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Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
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1

Integrated inorganic membrane electrode assembly with layered double hydroxides as ionic conductors for anion exchange membrane water electrolysis  

Science Journals Connector (OSTI)

Abstract In this work, we report a novel integrated inorganic membrane electrode assembly (I2MEA) for anion exchange membrane (AEM) water electrolysis by using inorganic Mg-Al layered double hydroxides (Mg-Al LDHs) as an ionic conductor. Mg-Al \\{LDHs\\} synthesized by a two-step approach exhibit high hydroxide ion conductivity and superior stability. The resultant ionic conducting nanoparticles are cold-pressed to form a membrane and mixed with a non-precious electrocatalyst to form the catalyst layer onto each side of the membrane. As such, an I2MEA is formed and used in a water electrolysis setup. It is shown that the present water electrolysis results in a maximum current density of 208 mA cm?2 with 0.1 M NaOH as the electrolyte and a cutoff voltage of 2.2 V at 70 °C. More impressively, using 0.1 M Na2CO3 as the electrolyte, the \\{I2MEAs\\} can continuously electrolyze at 80 mA cm?2 for 600 hours with a decay rate of as low as 100 ?V h?1. This superior stability is attributed to the integrated structure that allows hydroxide ions to transport smoothly.

L. Zeng; T.S. Zhao

2015-01-01T23:59:59.000Z

2

Affordable Hydrogen Fuel Cell Vehicles: Quaternary Phosphonium Based Hydroxide Exchange Membranes  

SciTech Connect

Broad Funding Opportunity Announcement Project: The University of Delaware is developing a new fuel cell membrane for vehicles that relies on cheaper and more abundant materials than those used in current fuel cells. Conventional fuel cells are very acidic, so they require acid-resistant metals like platinum to generate electricity. The University of Delaware is developing an alkaline fuel cell membrane that can operate in a non-acidic environment where cheaper materials like nickel and silver, instead of platinum, can be used. In addition to enabling the use of cheaper metals, the University of Delaware’s membrane is 500 times less expensive than other polymer membranes used in conventional fuel cells.

None

2010-01-01T23:59:59.000Z

3

Anion exchange membrane  

DOE Patents (OSTI)

An anion exchange membrane and fuel cell incorporating the anion exchange membrane are detailed in which proazaphosphatrane and azaphosphatrane cations are covalently bonded to a sulfonated fluoropolymer support along with anionic counterions. A positive charge is dispersed in the aforementioned cations which are buried in the support to reduce the cation-anion interactions and increase the mobility of hydroxide ions, for example, across the membrane. The anion exchange membrane has the ability to operate at high temperatures and in highly alkaline environments with high conductivity and low resistance.

Verkade, John G; Wadhwa, Kuldeep; Kong, Xueqian; Schmidt-Rohr, Klaus

2013-05-07T23:59:59.000Z

4

Morphology of Ion Exchange Membranes  

Science Journals Connector (OSTI)

......the HjO,- treatment of the ion exchange...and rinsed with water. After drying...Determined in sea water at 25 C by electrodialysis. Fig. 2. Neosepta...with deionized water, treated with...prepared by the treatment of the cation......

Yoshikazu HORI; Toru NAKATANI; Yukio MIZUTANI

1986-10-01T23:59:59.000Z

5

Anion Exchange Membranes for Fuel Cells | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Anion Exchange Membranes for Fuel Cells Anion Exchange Membranes for Fuel Cells Presentation at the AMFC Workshop, May 8-9, 2011, Arlington, VA amfc110811herring.pdf More...

6

Anion Exchange Membranes - Transport/Conductivity  

NLE Websites -- All DOE Office Websites (Extended Search)

Fundamental understanding Fundamental understanding * Driving membranes towards applications Anion Exchange Membranes - Transport/Conductivity High Priority * A need for a standard/available AEM (similar to Nafion in PEMs) * Define standard experimental conditions and protocols * A need for much more fundamental studies in transport mechanisms and mechanical properties * A need to develop much more new AEMs with alternative chemistries (new cation and backbone chemistries) Fundamental Studies * TRANSPORT * Conductivity (pure OH - hard to measure) * Water content, λ * Diffusion coefficients, NMR * Drag coefficients * Transference * Solubility * Fundamental transport mechanisms for anion and water transport * Computational Modeling * MORPHOLOGY/CHEMISTRY * Vibrational Spectroscopy: FTIR, Raman

7

Epoxy-crosslinked sulfonated poly (phenylene) copolymer proton exchange membranes  

DOE Patents (OSTI)

An epoxy-crosslinked sulfonated poly(phenylene) copolymer composition used as proton exchange membranes, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cell, in electrode casting solutions and electrodes, and in sulfur dioxide electrolyzers. These improved membranes are tougher, have higher temperature capability, and lower SO.sub.2 crossover rates.

Hibbs, Michael (Albuquerque, NM); Fujimoto, Cy H. (Albuquerque, NM); Norman, Kirsten (Albuquerque, NM); Hickner, Michael A. (State College, PA)

2010-10-19T23:59:59.000Z

8

Recovery of acids and sodium hydroxide from solutions of sodium sulfate and sodium chloride with the use of bipolar membranes  

SciTech Connect

The authors examined the kinetic laws governing the electrodialysis recovery of hydrochloric acid and sulfuric acid, as well as sodium hydroxide, from 1M sodium chloride and 0.5 M sodium sulfate solutions and from a mixture of these salts with the use of the MB-1, MB-2, and MB-3 bipolar membranes. Kinetic plots of the current density and the concentration of the acid and the base in the chambers next to the bipolar membranes during the electrodialysis treatment of 1M sodium chloride, 0.5 M sodium sulfate, and solutions are presented. It was established that it is better to use the MB-3 membrane for the electrodialysis conversion of sodium chloride and sodium sulfate into acids and sodium hydroxide owing to the high rate and current efficiency and low expenditure of electrical energy and degree of contamination of the products obtained by the salts. It was also established that the resistance of the MB-1 and MB-2 bipolar membranes is almost an order of magnitude higher than that of the MB-3 membrane.

Bobrinskaya, G.A.; Pavlova, T.V.; Shatalov, A.Ya.

1985-09-01T23:59:59.000Z

9

Journal of Membrane Science 239 (2004) 1726 Highly conductive ordered heterogeneous ion-exchange membranes  

E-Print Network (OSTI)

in the matrix required for reasonable ion transport through the membrane is 50­70 wt.% [2Journal of Membrane Science 239 (2004) 17­26 Highly conductive ordered heterogeneous ion-exchange membranes are used in electrodialysis (ED) as ion-selective membranes and in power sources (such as fuel

Freger, Viatcheslav "Slava"

10

Some durability considerations for proton exchange membranes...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Oct. 14, 2010 hightemphamrock.pdf More Documents & Publications New Membranes for PEM Fuel Cells Model Compound Studies of Fuel Cell Membrane Degradation Processing-Performance...

11

Some durability considerations for proton exchange membranes  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

creates an aggressive environment for the electrolyte membrane. This includes: - Mechanical stresses related to changes in the level of membrane hydration. - Thermal...

12

Electrodeposition of microparticles on polarized ion exchange membranes  

SciTech Connect

The use of ion exchange membranes to extract microparticles from an aqueous solution is considered. The efficiency of removing negatively charged aerosil particles depends substantially on the nature of the membrane located at the anode. It has been established that besides an increase in the electric field intensity the principal factor ensuring an increase in the efficiency of purifying a solution by electrodeposition of microparticles on a membrane surface is a reduction in the flowrate relative to the membrane surface.

Verbich, S.V.; Ponomarev, M.I.; Grebenyuk, V.D.; Dukhin, S.S.

1986-11-01T23:59:59.000Z

13

Ammonium Bicarbonate Transport in Anion Exchange Membranes for Salinity Gradient Energy  

Science Journals Connector (OSTI)

Ammonium Bicarbonate Transport in Anion Exchange Membranes for Salinity Gradient Energy ... Current status of ion exchange membranes for power generation from salinity gradients ...

Geoffrey M. Geise; Michael A. Hickner; Bruce E. Logan

2013-08-22T23:59:59.000Z

14

Optimized Anion Exchange Membranes for Vanadium Redox Flow Batteries  

Science Journals Connector (OSTI)

vanadium redox flow battery; anion exchange membrane; ion exchange capacity; cycling performance; power density ... All electrochemical measurements were conducted using a fully automated redox flow battery testing system (Scribner 857 Redox Flow Cell System). ... Characteristics of a new all-vanadium redox flow battery ...

Dongyang Chen; Michael A. Hickner; Ertan Agar; E. Caglan Kumbur

2013-06-25T23:59:59.000Z

15

Blend Membranes of Highly Phosphonated Polysulfone and Polybenzimidazoles for High Temperature Proton Exchange Membrane Fuel Cells  

E-Print Network (OSTI)

Energy, Office of Hydrogen, Fuel Cells and InfrastructureD. Kreuer, and J. Maier, Fuel Cells 5, 335 2. M. A. Hickner,Proton Exchange Membrane Fuel Cells R. A. Potrekar † , K. T.

Potrekar, Ravindra

2014-01-01T23:59:59.000Z

16

DOE Hydrogen Analysis Repository: Cost Analysis of Proton Exchange Membrane  

NLE Websites -- All DOE Office Websites (Extended Search)

Cost Analysis of Proton Exchange Membrane Fuel Cell Systems for Cost Analysis of Proton Exchange Membrane Fuel Cell Systems for Transportation Project Summary Full Title: Cost Analysis of Proton Exchange Membrane (PEM) Fuel Cell Systems for Transportation Project ID: 196 Principal Investigator: Eric Carlson Keywords: Fuel cells, fuel cell vehicles (FCV), transportation, costs Purpose Assess the cost of an 80 kW direct hydrogen fuel cell system relative to the DOE 2005 target of $125/kW. The system includes the fuel cell stack and balance-of-plant (BOP) components for water, thermal, and fuel management, but not hydrogen storage. Performer Principal Investigator: Eric Carlson Organization: TIAX, LLC Address: 15 Acorn Park Cambridge, MA 02140-2328 Telephone: 617-498-5903 Email: carlson.e@tiaxllc.com Additional Performers: P. Kopf, TIAX, LLC; J. Sinha, TIAX, LLC; S. Sriramulu, TIAX, LLC

17

Ion-Exchange Membranes in the Chemical Process Industry  

Science Journals Connector (OSTI)

Other applications of ion-exchange membranes are still in an early state of their development, such as the redox flow battery. ... (40) More recently, interest in electrodialysis as a flow battery has increased and will be briefly discussed in the following. ... One is based on a reversal of regular electrodialysis and is referred to as “concentration flow battery”,(40) and the other is based on reversal of electrodialysis with bipolar membranes and is referred to as “neutralization flow battery”. ...

Heiner Strathmann; Andrej Grabowski; Gerhart Eigenberger

2013-03-13T23:59:59.000Z

18

Interfacial Water-Transport Effects in Proton-Exchange Membranes  

SciTech Connect

It is well known that the proton-exchange membrane is perhaps the most critical component of a polymer-electrolyte fuel cell. Typical membranes, such as Nafion(R), require hydration to conduct efficiently and are instrumental in cell water management. Recently, evidence has been shown that these membranes might have different interfacial morphology and transport properties than in the bulk. In this paper, experimental data combined with theoretical simulations will be presented that explore the existence and impact of interfacial resistance on water transport for Nafion(R) 21x membranes. A mass-transfer coefficient for the interfacial resistance is calculated from experimental data using different permeation cells. This coefficient is shown to depend exponentially on relative humidity or water activity. The interfacial resistance does not seem to exist for liquid/membrane or membrane/membrane interfaces. The effect of the interfacial resistance is to flatten the water-content profiles within the membrane during operation. Under typical operating conditions, the resistance is on par with the water-transport resistance of the bulk membrane. Thus, the interfacial resistance can be dominant especially in thin, dry membranes and can affect overall fuel-cell performance.

Kienitz, Brian; Yamada, Haruhiko; Nonoyama, Nobuaki; Weber, Adam

2009-11-19T23:59:59.000Z

19

Membrane permeation process for dehydration of organic liquid mixtures using sulfonated ion-exchange polyalkene membranes  

DOE Patents (OSTI)

A membrane permeation process for dehydrating a mixture of organic liquids, such as alcohols or close boiling, heat sensitive mixtures. The process comprises causing a component of the mixture to selectively sorb into one side of sulfonated ion-exchange polyalkene (e.g., polyethylene) membranes and selectively diffuse or flow therethrough, and then desorbing the component into a gas or liquid phase on the other side of the membranes.

Cabasso, Israel (131 Buckingham Ave., Syracuse, NY 13210); Korngold, Emmanuel (P.O. Box 1025, Beer-Sheva 84110, IL)

1988-01-01T23:59:59.000Z

20

Ion Exchange Membrane Cathodes for Scalable Microbial Fuel Cells  

Science Journals Connector (OSTI)

Ion Exchange Membrane Cathodes for Scalable Microbial Fuel Cells ... The optimum amount of graphite fibers needed for these brush electrodes has not yet been optimized, and the cathode remains the greatest challenge for MFC designs. ... Different catalyst locations (inside versus outside) and loadings, specific surface areas, and solution chemistry (solution conductivity) were examined to optimize performance. ...

Yi Zuo; Shaoan Cheng; Bruce E. Logan

2008-08-13T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

PROTON EXCHANGE MEMBRANE FUEL CELL OPERATION AND DEGRADATION IN SHORT-CIRCUIT  

E-Print Network (OSTI)

PROTON EXCHANGE MEMBRANE FUEL CELL OPERATION AND DEGRADATION IN SHORT-CIRCUIT R.E. Silvaa, b, d , F exchange membrane fuel cells, short circuit, degradation mechanism, electrochemical impedance spectroscopy an electrical short circuit of a proton exchange membrane fuel cell stack. The physical quantities in the fuel

Boyer, Edmond

22

HYDROGEN ISOTOPE RECOVERY USING PROTON EXCHANGE MEMBRANE ELECTROLYSIS OF WATER  

SciTech Connect

A critical component of tritium glovebox operations is the recovery of high value tritium from the water vapor in the glove box atmosphere. One proposed method to improve existing tritium recovery systems is to replace the disposable hot magnesium beds used to separate the hydrogen and oxygen in water with continuous use Proton Exchange Membrane Electrolyzers (PEMEs). This study examines radiation exposure to the membrane of a PEME and examines the sizing difference that would be needed if the electrolyzer were operated with a cathode water vapor feed instead of an anode liquid water feed.

Fox, E; Scott Greenway, S; Amy Ekechukwu, A

2007-08-27T23:59:59.000Z

23

Interpenetrating polymer network ion exchange membranes and method for preparing same  

DOE Patents (OSTI)

Interpenetrating polymer network ion exchange membranes include a microporous polymeric support film interpenetrated by an ion exchange polymer and are produced by absorbing and polymerizing monomers within the support film. The ion exchange polymer provides ion exchange ligands at the surface of and throughout the support film which have sufficient ligand mobility to extract and transport ions across the membrane.

Alexandratos, Spiro D. (Knoxville, TN); Danesi, Pier R. (Vienna, AT); Horwitz, E. Philip (Naperville, IL)

1989-01-01T23:59:59.000Z

24

Conductivity Measurements of Synthesized Heteropoly Acid Membranes for Proton Exchange Membrane Fuel Cells  

SciTech Connect

Fuel cell technology is receiving attention due to its potential to be a pollution free method of electricity production when using renewably produced hydrogen as fuel. In a Proton Exchange Membrane (PEM) fuel cell H2 and O2 react at separate electrodes, producing electricity, thermal energy, and water. A key component of the PEM fuel cell is the membrane that separates the electrodes. DuPont’s Nafion® is the most commonly used membrane in PEM fuel cells; however, fuel cell dehydration at temperatures near 100°C, resulting in poor conductivity, is a major hindrance to fuel cell performance. Recent studies incorporating heteropoly acids (HPAs) into membranes have shown an increase in conductivity and thus improvement in performance. HPAs are inorganic materials with known high proton conductivities. The primary objective of this work is to measure the conductivity of Nafion, X-Ionomer membranes, and National Renewable Energy Laboratory (NREL) Developed Membranes that are doped with different HPAs at different concentrations. Four-point conductivity measurements using a third generation BekkTech? conductivity test cell are used to determine membrane conductivity. The effect of multiple temperature and humidification levels is also examined. While the classic commercial membrane, Nafion, has a conductivity of approximately 0.10 S/cm, measurements for membranes in this study range from 0.0030 – 0.58 S/cm, depending on membrane type, structure of the HPA, and the relative humidity. In general, the X-ionomer with H6P2W21O71 HPA gave the highest conductivity and the Nafion with the 12-phosphotungstic (PW12) HPA gave the lowest. The NREL composite membranes had conductivities on the order of 0.0013 – 0.025 S/cm.

Record, K.A.; Haley, B.T.; Turner, J.

2006-01-01T23:59:59.000Z

25

DEVELOPMENT AND SELECTION OF IONIC LIQUID ELECTROLYTES FOR HYDROXIDE CONDUCTING POLYBENZIMIDAZOLE MEMBRANES IN ALKALINE FUEL CELLS  

SciTech Connect

Alkaline fuel cell (AFC) operation is currently limited to specialty applications such as low temperatures and pure H{sub 2}/O{sub 2} due to the corrosive nature of the electrolyte and formation of carbonates. AFCs are the cheapest and potentially most efficient (approaching 70%) fuel cells. The fact that non-Pt catalysts can be used, makes them an ideal low cost alternative for power production. The anode and cathode are separated by and solid electrolyte or alkaline porous media saturated with KOH. However, CO{sub 2} from the atmosphere or fuel feed severely poisons the electrolyte by forming insoluble carbonates. The corrosivity of KOH (electrolyte) limits operating temperatures to no more than 80?C. This chapter examines the development of ionic liquids electrolytes that are less corrosive, have higher operating temperatures, do not chemically bond to CO{sub 2}, and enable alternative fuels. Work is detailed on the IL selection and characterization as well as casting methods within the polybenzimidazole based solid membrane. This approach is novel as it targets the root of the problem (the electrolyte) unlike other current work in alkaline fuel cells which focus on making the fuel cell components more durable.

Fox, E.

2012-05-01T23:59:59.000Z

26

Alkaline stable C2-substituted imidazolium-based cross-linked anion exchange membranes for alkaline fuel cell applications  

Science Journals Connector (OSTI)

Abstract Novel C2-substituted imidazolium-based cross-linked anion exchange membranes (AEMs) are prepared via irradiation with ultraviolet light cross-linking of styrene, acrylonitrile and 1,3-diallyl-2-methyl imidazolium bromine ([DAMIm][Br]), and followed by anion exchange with hydroxide ions. [DAMIm][Br] is synthesized and used both as crosslinker and hydrophilic phase. The ionic conductivity of the \\{AEMs\\} increases with increasing [DAMIm][Br] content due to the hydrophilic regions and the continuous hydrophilic polymeric networks formed in the membranes. The imidazolium-based cross-linked \\{AEMs\\} show excellent thermal stabilities, and the membrane which containing 30% mass fraction of [DAMIm][Br] shows ionic conductivity up to 2.0 × 10?2 S cm?1 and good long-term chemical stability in 1 M KOH solution. The results of this study suggest that the C2-substituted imidazolium-based cross-linked \\{AEMs\\} have good perspectives for alkaline fuel cell applications.

Bencai Lin; Fuqiang Chu; Yurong Ren; Baoping Jia; Ningyi Yuan; Hui Shang; Tianying Feng; Yuanyuan Zhu; Jianning Ding

2014-01-01T23:59:59.000Z

27

Material properties of cation exchange membranes for chloralkali electrolysis, water electrolysis and fuel cells  

Science Journals Connector (OSTI)

Owing to the development of perfluorinated ion-exchange membranes, the application of the membranes in electrochemical cells has advanced greatly, especially in chloralkali electrolysis. Material properties of pe...

T. Asawa

1989-07-01T23:59:59.000Z

28

Proton Exchange Membrane Fuel Cells for Electrical Power Generation On-Board Commercial Airplanes  

Energy.gov (U.S. Department of Energy (DOE))

This report is an initial investigation of the use of proton exchange membrane (PEM) fuel cells on-board commercial aircraft.

29

Identification and Characterization of Near-Term Direct Hydrogen Proton Exchange Membrane Fuel Cell Markets  

Energy.gov (U.S. Department of Energy (DOE))

This document provides information about near-term markets (such as for forklifts and telecommunications) for proton exchange membrane fuel cells.

30

Dynamic characteristics of a commercial Proton Exchange Membrane (PEM) fuel cell.  

E-Print Network (OSTI)

??Fast growing application of Proton Exchange Membrane (PEM) Fuel Cell in automotive industries, has brought the necessity of conducting research on automotive aspects of the… (more)

Toutounchian, Hamid

2008-01-01T23:59:59.000Z

31

Bio-engineered gas diffusion electrodes (GDEs) for proton exchange membrane fuel cells (PEMFCs).  

E-Print Network (OSTI)

??The current cost and finite nature of Platinum Group Metals (PGM) is a barrier to the successful commercialisation of Proton Exchange Membrane Fuel Cells (PEMFCs).… (more)

Courtney, James Matthew

2011-01-01T23:59:59.000Z

32

Charge Transport through a Novel Zeolite Y Membrane by a Self-Exchange Process Hyunjung Lee and Prabir K. Dutta*  

E-Print Network (OSTI)

Charge Transport through a Novel Zeolite Y Membrane by a Self-Exchange Process Hyunjung Lee-photoresist-coated membranes were found. Accessibility of the intrazeolitic volume was examined by ion exchange and for optimally illuminated membranes was comparable to uncoated membranes. Charge transport through the membrane

Dutta, Prabir K.

33

Application of Neural Network approach for Proton Exchange Membrane fuel cell systems  

Science Journals Connector (OSTI)

Artificial Intelligence (AI) techniques, particularly the Neural Networks (NNs), are recently having significant impact on power electronics. In a Proton Exchange Membrane (PEM) fuel cell system, there is a strong relationship between the available ... Keywords: NNC, PEM fuel cells, dynamic modelling, neural network controllers, neural networks, output variables, performance modelling, power electronics, proton exchange membrane

Mustapha Hatti; Mustapha Tioursi

2009-01-01T23:59:59.000Z

34

Proton Exchange Membrane Fuel Cell degradation prediction based on Adaptive Neuro Fuzzy Inference Systems  

E-Print Network (OSTI)

Proton Exchange Membrane Fuel Cell degradation prediction based on Adaptive Neuro Fuzzy Inference online XX XX XXXX Keywords: Proton Exchange Membrane fuel cell degradation, Prognostic and Health nominal operating condition of a PEM fuel cell stack. It proposes a methodology based on Adaptive Neuro

Paris-Sud XI, Université de

35

Membrane resistance: The effect of salinity gradients over a cation exchange membrane  

Science Journals Connector (OSTI)

Abstract Ion exchange membranes (IEMs) are used for selective transport of ions between two solutions. These solutions are often different in concentration or composition. The membrane resistance (RM) is an important parameter affecting power consumption or power production in electrodialytic processes. In contrast to real applications, often RM is determined while using a standard 0.5 M NaCl external solution. It is known that RM increases with decreasing concentration. However, the detailed effect of a salinity gradient present over an IEM on RM was not known, and is studied here using alternating and direct current. NaCl solution concentrations varied from 0.01 to 1.1 M. The results show that RM is mainly determined by the lowest external concentration. RM can be considered as two resistors in series i.e. a gel phase (concentration independent) and an ionic solution phase (concentration dependent). The membrane conductivity is limited by the conductivity of the ionic solution when the external concentration, cext<0.3 M. The membrane conductivity is limited by the conductivity of the gel phase when cext?0.3 M, then differences of RM are small. A good approximation of experimentally determined RM can be obtained. The internal ion concentration profile is a key factor in modeling RM.

A.H. Galama; D.A. Vermaas; J. Veerman; M. Saakes; H.H.M. Rijnaarts; J.W. Post; K. Nijmeijer

2014-01-01T23:59:59.000Z

36

DEVELOPMENT OF NOVEL ELECTROCATALYSTS FOR PROTON EXCHANGE MEMBRANE FUEL CELLS  

SciTech Connect

Fuel cells are electrochemical devices that convert the available chemical free energy directly into electrical energy, without going through heat exchange process. Of all different types of fuel cells, the Proton Exchange Membrane Fuel Cell (PEMFC) is one of the most promising power sources for stand-alone utility and electric vehicle applications. Platinum (Pt) Catalyst is used for both fuel and air electrodes in PEMFCs. However, carbon monoxide (CO) contamination of H{sub 2} greatly affects electro catalysts used at the anode of PEMFCs and decreases cell performance. The irreversible poisoning of the anode can occur even in CO concentrations as low as few parts per million (ppm). In this work, we have synthesized several novel elctrocatalysts (Pt/C, Pt/Ru/C, Pt/Mo/C, Pt/Ir and Pt/Ru/Mo) for PEMFCs. These catalysts have been tested for CO tolerance in the H{sub 2}/air fuel cell, using CO concentrations in the H{sub 2} fuel that varies from 10 to 100 ppm. The performance of the electrodes was evaluated by determining the cell potential against current density. The effects of catalyst composition and electrode film preparation method on the performance of PEM fuel cell were also studied. It was found that at 70 C and 3.5 atm pressure at the cathode, Pt-alloy catalyst (10 wt% Pt/Ru/C, 20 wt% Pt/Mo/C) were more CO tolerant than the 20 wt% Pt/C catalyst alone. It was also observed that spraying method was better than the brushing technique for the preparation of electrode film.

Shamsuddin Ilias

2003-04-24T23:59:59.000Z

37

DEVELOPMENT OF NOVEL ELECTROCATALYSTS FOR PROTON EXCHANGE MEMBRANE FUEL CELLS  

SciTech Connect

The Proton Exchange Membrane Fuel Cell (PEMFC) is one of the most promising power sources for stand-alone utility and electric vehicle applications. Platinum (Pt) Catalyst is used for both fuel and air electrodes in PEMFCs. However, carbon monoxide (CO) contamination of H{sub 2} greatly affects electro catalysts used at the anode of PEMFCs and decreases cell performance. The irreversible poisoning of the anode can occur even in CO concentrations as low as few parts per million (ppm). In this work, we have synthesized several novel elctrocatalysts (Pt/C, Pt/Ru/C, Pt/Mo/C, Pt/Ir and Pt/Ru/Mo) for PEMFCs. These catalysts have been tested for CO tolerance in the H{sub 2}/air fuel cell, using CO concentrations in the H{sub 2} fuel that varies from 10 to 100 ppm. The performance of the electrodes was evaluated by determining the cell potential against current density. The effects of catalyst composition and electrode film preparation method on the performance of PEM fuel cell were also studied. It was found that at 70 C and 3.5 atm pressure at the cathode, Pt-alloy catalyst (10 wt% Pt/Ru/C, 20 wt% Pt/Mo/C) were more CO tolerant than the 20 wt% Pt/C catalyst alone. It was also observed that spraying method was better than the brushing technique for the preparation of electrode film.

Shamsuddin Ilias

2002-06-11T23:59:59.000Z

38

DEVELOPMENT OF NOVEL ELECTROCATALYST FOR PROTON EXCHANGE MEMBRANE FUEL CELLS  

SciTech Connect

Proton-exchange membrane fuel cell (PEMFC) is one of the strongest contenders as a power source for space & electric vehicle applications. Platinum catalyst is used for both fuel and air electrodes in PEMFCs. CO contamination of H{sub 2} greatly affects electrocatalysts used at the anode of polymer electrolyte fuel cells and decrease the cell performance. Pt-Ru catalyst had been recognized to alleviate this problem by showing better tolerance to CO poisoning than only Pt catalyst. This irreversible poisoning of the anode can be happened even in concentrations as little as a few ppm, and therefore, require expensive scrubbing to reduce the contaminant concentration to acceptable level. In order to commercialize this environmentally sound source of energy/power system, development of suitable impurity tolerant catalyst is needed. This project will develop novel electrocatalysts for the PEMFCs and demonstrate the feasibility of a H{sub 2}/O{sub 2} fuel cell base on these materials. This project, if successful, will reduce the costs due to reduce Pt catalyst loading or use non-precious metals. It will increase the PEM fuel cell performance by increasing catalyst tolerance to methanol oxidation intermediate products (CO) and fuel impurities (H{sub 2}S), which will generate substantial interest for commercialization of the PEM fuel cell technology.

Shamsuddin Ilias

2000-01-19T23:59:59.000Z

39

Interfacial Water-Transport Effects in Proton-Exchange Membranes  

E-Print Network (OSTI)

Materials Modeling in Pem Fuel Cells, A  Combination Model Ionomer Membranes for Pem?Fuel Cells," Electrochimica Acta, 

Kienitz, Brian

2010-01-01T23:59:59.000Z

40

X-ray Line Profile Analysis of Nanoparticles in Proton Exchange Membrane Fuel Cell Electrodes  

Science Journals Connector (OSTI)

We present a method to extract X-ray diffraction patterns from a multiphase system and analyze the particle size distribution of each phase. The method is demonstrated for crystalline nanoparticles in the electrodes of proton exchange membrane fuel cells (...

Matthias Loster; Davor Balzar; K. Andreas Friedrich; Jürgen Garche

2007-06-06T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

A model and simulation of cathode flooding and drying on unsteady proton exchange membrane fuel cell  

Science Journals Connector (OSTI)

A water balance has a significant impact on the overall system performance in proton exchange membrane fuel cell. An actual fuel cell application has a dynamic electrical load which means also dynamic electrical ...

A. Bakhtiar; Young-Bok Kim; Jin-Kwang You…

2012-09-01T23:59:59.000Z

42

A New Hybrid Proton-Exchange-Membrane Fuel Cells-Battery Power System with Efficiencies Considered  

Science Journals Connector (OSTI)

Hybrid systems, based on lead-acid or lithium-ion batteries and proton-exchange-membrane fuel cells (PEMFCs), give the possibility of ... results show that the combination of lead-acid batteries or lithium-ion batteries

Chung-Hsing Chao; Jenn-Jong Shieh

2013-01-01T23:59:59.000Z

43

DEVELOPMENT OF NOVEL ELECTROCATALYSTS FOR PROTON EXCHANGE MEMBRANE FUEL CELLS  

SciTech Connect

Proton Exchange Membrane Fuel Cell (PEMFC) is one of the most promising power sources for space and electric vehicle applications. Platinum (Pt) catalyst is used for both fuel and air electrodes in PEMFCs. The carbon monoxide (CO) contamination of H{sub 2} greatly affects electrocatalysts used at the anode of PEMFCs and decrease the cell performance. This irreversible poisoning of the anode can happen even in CO concentrations as low as few ppm, and therefore, require expensive scrubbing of the H{sub 2}-fuel to reduce the contaminant concentration to acceptable level. In order to commercialize this environmentally sound source of energy/power system, development of suitable CO-tolerant catalyst is needed. In this work, we have synthesized several novel electrocatalysts (Pt/C, Pt/Ru/C Pt/Mo/C, Pt/Ir and Pt/Ru/Mo) for PEMFCs. These catalysts have been tested for CO tolerance in the H{sub 2}/air fuel cell. The concentration of CO in the H{sub 2} fuel varied from 10 ppm to 100 ppm. The performance of the electrodes was evaluated by determining the cell potential against current density. The effect of temperature, catalyst compositions, and electrode film preparation methods on the performance of PEM fuel cell has also been studied. It was found that at 70 C and 3.5 atm pressure at the cathode, Pt-alloy catalysts (10 wt % Pt/Ru/C, 20 wt % Pt/Mo/C) were more CO-tolerant than 20 wt % Pt catalyst alone. It was also observed that spraying method is better for the preparation of electrode film than the brushing technique. Some of these results are summarized in this report.

Shamsuddin Ilias

2001-07-06T23:59:59.000Z

44

SWNT?MWNT Hybrid Architecture for Proton Exchange Membrane Fuel Cell Cathodes  

Science Journals Connector (OSTI)

SWNT?MWNT Hybrid Architecture for Proton Exchange Membrane Fuel Cell Cathodes ... A thin film of single-wall carbon nanotubes (SWNTs) and SWNT?multiwall carbon nanotube (MWNT) hybrids loaded with Pt have been evaluated as the cathode catalyst layer in proton exchange membrane fuel cells. ... Hydrogen, Fuel Cells & Infrastructure Technologies Program: Multi-Year Research, Development and Demonstration Plan: Planned Program Activities for 2003?2010; U.S. Department of Energy: Energy Efficiency and Renewable Energy: January 21, 2005. ...

Palanisamy Ramesh; Mikhail E. Itkis; Jason M. Tang; Robert C. Haddon

2008-05-28T23:59:59.000Z

45

The Dynamics of Platinum Precipitation in an Ion Exchange Membrane  

E-Print Network (OSTI)

Microscopy of polymer electrolyte membranes that have undergone operation under fuel cell conditions, have revealed a well defined band of platinum in the membrane. Here, we propose a physics based model that captures the mechanism of platinum precipitation in the polymer electrolyte membrane. While platinum is observed throughout the membrane, the preferential growth of platinum at the band of platinum is dependent on the electrochemical potential distribution in the membrane. In this paper, the location of the platinum band is calculated as a function of the gas concentration at the cathode and anode, gas diffusion coefficients and solubility constants of the gases in the membrane, which are functions of relative humidity. Under H2/N2 conditions the platinum band is located near the cathode-membrane interface, as the oxygen concentration in the cathode gas stream increases and/or the hydrogen concentration in the anode gas stream decreases, the band moves towards the anode. The model developed in this paper...

Burlatsky, S F; Atrazhev, V V; Dmitriev, D V; Kuzminyh, N Y; Erikhman, N S

2013-01-01T23:59:59.000Z

46

Water uptake, ionic conductivity and swelling properties of anion-exchange membrane  

E-Print Network (OSTI)

occurs with negative excess volume of mixing. Percolative nature of the ion transport has been is reduced at the cathode to produce OHÃ? , which transports through the anion-exchange membrane (AEM membrane, AEM can conduct ions only in the presence of water. In addition, water is one of the reactants

47

Patterned ion exchange membranes for improved power production in microbial reverse-electrodialysis cells  

E-Print Network (OSTI)

Patterned ion exchange membranes for improved power production in microbial reverse-electrodialysis August 2014 Keywords: Microbial reverse electrodialysis cell Patterned membranes Integrated spacer Internal resistance a b s t r a c t Power production in microbial reverse-electrodialysis cells (MRCs) can

48

Growth of Pt nanoparticle for proton-exchange-membrane fuel cells by  

E-Print Network (OSTI)

at anode side of a polymer electrolyte membrane (PEM) fuel cell. With a Pt loading of 25 g-Pt/cm2 , current, PEM fuel cell, Mass specific power density, Electrochemical active surface area, Oxygen reduction PEMFC Growth of Pt nanoparticle for proton-exchange-membrane fuel cells

49

Anhydrous Phosphoric Acid Functionalized Sintered Mesoporous Silica Nanocomposite Proton Exchange Membranes for Fuel Cells  

Science Journals Connector (OSTI)

Anhydrous Phosphoric Acid Functionalized Sintered Mesoporous Silica Nanocomposite Proton Exchange Membranes for Fuel Cells ... The cell performance and stability may be further improved through an optimization of the interfacial contact between the electrocatalytic layer and the inorganic membrane. ... polycondensation procedure was optimized for individual case of PBI synthesis in order to obtain inherent viscosity of ?1 dL/g. ...

Jie Zeng; Beibei He; Krystina Lamb; Roland De Marco; Pei Kang Shen; San Ping Jiang

2013-10-14T23:59:59.000Z

50

Multi-block sulfonated poly(phenylene) copolymer proton exchange membranes  

DOE Patents (OSTI)

Improved multi-block sulfonated poly(phenylene) copolymer compositions, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cells, in electrode casting solutions and electrodes. The multi-block architecture has defined, controllable hydrophobic and hydrophilic segments. These improved membranes have better ion transport (proton conductivity) and water swelling properties.

Fujimoto, Cy H. (Albuquerque, NM); Hibbs, Michael (Albuquerque, NM); Ambrosini, Andrea (Albuquerque, NM)

2012-02-07T23:59:59.000Z

51

Highly Conductive Anion Exchange Membrane for High Power Density Fuel-Cell Performance  

Science Journals Connector (OSTI)

membranes (fueled with H or MeOH) and also to identify candidate alk. ... Anion exchange membranes (AEMs) provide one possible route to low platinum or platinum-free fuel cells with the potential for facile oxidn. of complex fuels beyond hydrogen and methanol. ... Price, S. C.; Ren, X. M.; Jackson, A. C.; Ye, Y. S.; Elabd, Y. A.; Beyer, F. L.Bicontinuous Alkaline Fuel Cell Membranes from Strongly Self-Segregating Block Copolymers Macromolecules 2013, 46, 7332– 7340 ...

Xiaoming Ren; Samuel C. Price; Aaron C. Jackson; Natalie Pomerantz; Frederick L. Beyer

2014-08-05T23:59:59.000Z

52

Nanocomposite reverse electrodialysis (RED) ion-exchange membranes for salinity gradient power generation  

Science Journals Connector (OSTI)

Abstract Despite the important role of ion-exchange membranes (IEMs) in reverse electrodialysis (RED) systems, the current absence of proper ion-exchange membranes delays the sustainable development of the RED process for salinity gradient power generation. This research presents the preparation of a new type of organic–inorganic nanocomposite cation exchange membrane and its performance characteristics. The combination of functionalized iron (III) oxide ( Fe 2 O 3 - SO 4 2 ? ) as an inorganic filler with the sulfonated poly (2,6-dimethyl-1,4-phenylene oxide) (sPPO) polymer matrix proved to have great potential for power generation by RED. The results showed that an optimal amount of Fe 2 O 3 - SO 4 2 ? (0.5–0.7 wt%) enhanced the key electrochemical properties of the ion-exchange membranes including a permselectivity up to 87.65% and an area resistance of 0.87 ? cm2. The nanocomposite membrane containing 0.7 wt% ( Fe 2 O 3 - SO 4 2 ? ) achieved a maximum power density (amount of power per unit membrane area) of 1.3 W m?2, which is relatively higher than that of the commercially available CSO (SelemionTM, Japan) membranes. The goal of the present work is to maximize the salinity gradient power generation by developing RED-specific nanocomposite IEMs. The results show the potential of the new design of the nanocomposite \\{IEMs\\} for viable energy generation by RED.

Jin Gi Hong; Yongsheng Chen

2014-01-01T23:59:59.000Z

53

Hydroxide Degradation Pathways for Substituted Trimethylammonium Cations: A DFT Study  

SciTech Connect

Substituted trimethylammonium cations serve as small molecule analogues for tetherable cations in anion exchange membranes. In turn, these membranes serve as the basis for alkaline membrane fuel cells by allowing facile conduction of hydroxide. As these cations are susceptible to hydroxide attack, they degrade over time and greatly limit the lifetime of the fuel cell. In this research, we performed density functional theory calculations to investigate the degradation pathways of substituted trimethylammonium cations to probe the relative durability of cation tethering strategies in alkyl and aromatic tethers. Our results show that significant changes in calculated energy barriers occur when substitution groups change. Specifically, we have found that, when available, the Hofmann elimination pathway is the most vulnerable pathway for degradation; however, this barrier is also found to depend on the carbon chain length and number of hydrogens susceptible to Hofmann elimination. S{sub N}2 barriers were also investigated for both methyl groups and substitution groups. The reported findings give important insight into potential tethering strategies for trimethylammonium cations in anion exchange membranes.

Long, H.; Kim, K.; Pivovar, B. S.

2012-05-03T23:59:59.000Z

54

Modeling a Proton Exchange Membrane Fuel Cell using Non-Equilibrium Thermodynamics: A Second Law analysis of assumptions and parameters:.  

E-Print Network (OSTI)

??In this work, a model derived from Non-Equilibrium Thermodynamics, for the Proton Exchange Membrane Fuel Cell, was utilized in order to explore the effect of… (more)

Garcia Navarro, J.C.

2014-01-01T23:59:59.000Z

55

New Membranes for High Temperature Proton Exchange Membrane Fuel Cells Based on Heteropoly Acids  

Energy.gov (U.S. Department of Energy (DOE))

"Summary of Colorado School of Mines heteropolyacid research presented to the High Temperature Membrane Working Group Meeting, Orlando FL, October 17, 2003 "

56

Transport of copper ammines through a cation-exchange membrane during electrodialysis  

SciTech Connect

Extraction of copper ammine complexes from waste waters in electroplating technology and in production of cuprammonium fibers is an important problem and electrodialysis with ion-exchange membranes is the most promising method of solving it. The authors aim was to study transport of copper(II) ammines through a commercial cation-exchange membrane of the MK-40 type. The electrodialyzer consisted of five Plexiglas compartments separated in alternating order by MK-40 cation-exchange and MA-40 anion-exchange membranes. The authors studied the dependence of the transport of copper(II) ammine complexes on the current density at copper concentration 0.025 M in the desalination compartment and 0.15 M ammonia concentration. The experiments lead to the conclusion that electrodialysis of copper(II) ammine complexes is possible only at current densities below the limiting values and that the transport is accompanied by decrease of the formation function of the complexes both in the membrane and in the solution of the concentrate receiving compartment.

Kireeva, L.D.; Shaposhnik, V.A.; Sorokina, V.I.

1987-09-10T23:59:59.000Z

57

Performance of a direct ethylene glycol fuel cell with an anion-exchange membrane  

E-Print Network (OSTI)

of an anion-exchange membrane with non-platinum electrocatalysts at both the anode and cathode on the development and performance test of an alkaline direct ethylene glycol fuel cell. The fuel cell consists with the existing electrocatalysts at low temperatures; as a result, the main product of ethanol oxidation reaction

Zhao, Tianshou

58

Instability of Pt/C Electrocatalysts in Proton Exchange Membrane Fuel Cells  

E-Print Network (OSTI)

catalysts. Catalyst durability during PEMFC operation remains a key challenge to developing PEMFCsInstability of Pt/C Electrocatalysts in Proton Exchange Membrane Fuel Cells A Mechanistic/C electrocatalyst sample in 0.5 M H2SO4 at 80°C were found to increase with applied potential from 0.9 to 1.1 V vs

Ferreira, Paulo J.

59

Electrochemical Removal of Carbon Monoxide in Reformate Hydrogen for Fueling Proton Exchange Membrane  

E-Print Network (OSTI)

Electrochemical Removal of Carbon Monoxide in Reformate Hydrogen for Fueling Proton Exchange Membrane Fuel Cells Sivagaminathan Balasubramanian, Charles E. Holland,* and John W. Weidner*,z Center in reformate hydrogen. In this design, the potential and gas flow are switched between the two filter cells so

Weidner, John W.

60

Growth of Carbon Support for Proton-Exchange-Membrane Fuel Cell by  

E-Print Network (OSTI)

Growth of Carbon Support for Proton-Exchange-Membrane Fuel Cell by Pulsed-Laser Deposition (PLDGDL)(catalyst) (pulsed laser deposition PLD) (plasma plume) () #12;III Abstract key word: Fuel CellPulsed Laser. People begin to develop fuel cells for seeking alternative energy sources. Fuel cell use the chemical

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61

160 C PROTON EXCHANGE MEMBRANE (PEM) FUEL CELL SYSTEM DEVELOPMENT  

SciTech Connect

The objectives of this program were: (a) to develop and demonstrate a new polymer electrolyte membrane fuel cell (PEMFC) system that operates up to 160 C temperatures and at ambient pressures for stationary power applications, and (b) to determine if the GTI-molded composite graphite bipolar separator plate could provide long term operational stability at 160 C or higher. There are many reasons that fuel cell research has been receiving much attention. Fuel cells represent environmentally friendly and efficient sources of electrical power generation that could use a variety of fuel sources. The Gas Technology Institute (GTI), formerly Institute of Gas Technology (IGT), is focused on distributed energy stationary power generation systems. Currently the preferred method for hydrogen production for stationary power systems is conversion of natural gas, which has a vast distribution system in place. However, in the conversion of natural gas into a hydrogen-rich fuel, traces of carbon monoxide are produced. Carbon monoxide present in the fuel gas will in time cumulatively poison, or passivate the active platinum catalysts used in the anodes of PEMFC's operating at temperatures of 60 to 80 C. Various fuel processors have incorporated systems to reduce the carbon monoxide to levels below 10 ppm, but these require additional catalytic section(s) with sensors and controls for effective carbon monoxide control. These CO cleanup systems must also function especially well during transient load operation where CO can spike 300% or more. One way to circumvent the carbon monoxide problem is to operate the fuel cell at a higher temperature where carbon monoxide cannot easily adsorb onto the catalyst and poison it. Commercially available polymer membranes such as Nafion{trademark} are not capable of operation at temperatures sufficiently high to prevent this. Hence this project investigated a new polymer membrane alternative to Nafion{trademark} that is capable of operation at temperatures up to 160 C.

L.G. Marianowski

2001-12-21T23:59:59.000Z

62

Review of Advanced Materials for Proton Exchange Membrane Fuel Cells  

Science Journals Connector (OSTI)

BASF reported on the long-term stability of its Celtec-P1100W membranes of more than 20?000 h with a 6 ?V/h voltage drop (160 °C and H2/air operation) “at optimized conditions”. ... Attempts to improve the stability of SPAEK have included optimization of the sulfonic group position (SPAEK is more stable if SO3 groups are attached to the pendant chain than to the main chain) and fluorination of the main-chain phenyl groups. ... Water management in PEFCs (polymer electrolyte fuel cells) is an important parameter to optimize for peak performance. ...

Alexander Kraytsberg; Yair Ein-Eli

2014-10-21T23:59:59.000Z

63

Investigations on degradation of the long-term proton exchange membrane water electrolysis stack  

Science Journals Connector (OSTI)

Abstract A 9-cell proton exchange membrane (PEM) water electrolysis stack is developed and tested for 7800 h. The average degradation rate of 35.5 ?V h?1 per cell is measured. The 4th MEA of the stack is offline investigated and characterized. The electrochemical impedance spectroscopy (EIS) shows that the charge transfer resistance and ionic resistance of the cell both increase. The linear sweep scan (LSV) shows the hydrogen crossover rate of the membrane has slight increase. The electron probe X-ray microanalyze (EPMA) illustrates further that Ca, Cu and Fe elements distribute in the membrane and catalyst layers of the catalyst-coated membranes (CCMs). The cations occupy the ion exchange sites of the Nafion polymer electrolyte in the catalyst layers and membrane, which results in the increase in the anode and the cathode overpotentials. The metallic impurities originate mainly from the feed water and the components of the electrolysis unit. Fortunately, the degradation was reversible and can be almost recovered to the initial performance by using 0.5 M H2SO4. This indicates the performance degradation of the stack running 7800 h is mainly caused by a recoverable contamination.

Shucheng Sun; Zhigang Shao; Hongmei Yu; Guangfu Li; Baolian Yi

2014-01-01T23:59:59.000Z

64

Carbon Nanotube Film by Filtration as Cathode Catalyst Support for Proton-Exchange Membrane Fuel Cell  

Science Journals Connector (OSTI)

Carbon Nanotube Film by Filtration as Cathode Catalyst Support for Proton-Exchange Membrane Fuel Cell ... 1-10 Some early investigations found that by using the normal paste method and simply replacing carbon black particles with disordered multiwalled CNTs as the support for Pt catalyst nanoparticles higher PEMFC and DMFC performances were achieved. ... activity of the CNT cathode catalysts was measured in a direct methanol fuel cell by use of a Pt-Ru/C anode, and use of a Nafion-115 membrane. ...

Wenzhen Li; Xin Wang; Zhongwei Chen; Mahesh Waje; Yushan Yan

2005-09-08T23:59:59.000Z

65

Mathematical Modeling of Cation Contamination in a Proton-exchange Membrane  

SciTech Connect

Transport phenomena in an ion-exchange membrane containing both H+ and K+ are described using multicomponent diffusion equations (Stefan-Maxwell). A model is developed for transport through a Nafion 112 membrane in a hydrogen-pump setup. The model results are analyzed to quantify the impact of cation contamination on cell potential. It is shown that limiting current densities can result due to a decrease in proton concentration caused by the build-up of contaminant ions. An average cation concentration of 30 to 40 percent is required for appreciable effects to be noticed under typical steady-state operating conditions.

Weber, Adam; Delacourt, Charles

2008-09-11T23:59:59.000Z

66

Correlating Humidity-Dependent Ionically Conductive Surface Area with Transport Phenomena in Proton-Exchange Membranes  

SciTech Connect

The objective of this effort was to correlate the local surface ionic conductance of a Nafion? 212 proton-exchange membrane with its bulk and interfacial transport properties as a function of water content. Both macroscopic and microscopic proton conductivities were investigated at different relative humidity levels, using electrochemical impedance spectroscopy and current-sensing atomic force microscopy (CSAFM). We were able to identify small ion-conducting domains that grew with humidity at the surface of the membrane. Numerical analysis of the surface ionic conductance images recorded at various relative humidity levels helped determine the fractional area of ion-conducting active sites. A simple square-root relationship between the fractional conducting area and observed interfacial mass-transport resistance was established. Furthermore, the relationship between the bulk ionic conductivity and surface ionic conductance pattern of the Nafion? membrane was examined.

He, Qinggang; Kusoglu, Ahmet; Lucas, Ivan T.; Clark, Kyle; Weber, Adam Z.; Kostecki, Robert

2011-08-01T23:59:59.000Z

67

A novel catalyst coated membrane embedded with Cs-substituted phosphotungstates for proton exchange membrane water electrolysis  

Science Journals Connector (OSTI)

Abstract Catalyst coated membrane (CCM) is the core component of proton exchange membrane (PEM) water electrolysis and the main place for electrochemical reaction and mass transfer. Its properties directly affect the performance of PEM water electrolysis. Aiming at decreasing the polarization loss and the ohmic loss, a novel CCM embedded with Cs1.5HPA in the skeleton of the Nafion® ionomer and the Nafion® membrane was prepared and possessed functionality of improved protonic conductivity. Meanwhile, the Cs1.5HPA-Nafion ionomer content in the catalyst layers was further optimized. The SEM, EDS and pore volume distribution measurement showed that the Cs1.5HPA embedded in the CCM without agglomeration and the micropore and mesopore were well distributed in the catalyst layer. Furthermore, \\{CCMs\\} were tested in a PEM water electrolyser at 80 °C, beneficial effects on both the Tafel slope and the iR loss were obtained due to the improved protonic conductivity as well as the appropriate pore structure and increased specific pore volume. The performance of the electrolyser cell was obviously improved with the novel CCM. The highest cell performance of 1.59 V at 2 A cm?2 was achieved at 80 °C. At 35 °C and 300 mA cm?2, the cell showed good durability within the test period of up to 570 h.

Gaoyang Liu; Junyuan Xu; Yituo Wang; Juming Jiang; Xindong Wang

2014-01-01T23:59:59.000Z

68

Mechanics of proton exchange membranes : time, temperature, and hydration dependence of the stress-strain behavior of persulfonated polytetrafluorethylene  

E-Print Network (OSTI)

Fuel cells are an important part of the future strategy for reducing dependence on fossil fuels as the world's supplies become more limited and greenhouse gasses become more of a concern. Proton Exchange Membrane Fuel Cells ...

Silberstein, Meredith N

2008-01-01T23:59:59.000Z

69

Predicting the Remaining Useful Lifetime of a Proton Exchange Membrane Fuel Cell using an Echo State Network  

E-Print Network (OSTI)

1 Predicting the Remaining Useful Lifetime of a Proton Exchange Membrane Fuel Cell using an Echo industrial Fuel Cell (FC) application resides in the system limited useful lifetime. Consequently, it Membrane Fuel Cell using an iterative predictive structure, which is the most common approach performing

Boyer, Edmond

70

DEVELOPMENT OF PROTOTYPE TITANATE ION EXCHANGE LOADED MEMBRANES FOR STRONTIUM, CESIUM AND ACTINIDE DECONTAMINATION FROM AQUEOUS MEDIA  

SciTech Connect

We have successfully incorporated high surface area particles of titanate ion exchange materials (monosodium titanate and crystalline silicotitanate) with acceptable particle size distribution into porous and inert support membrane fibrils consisting of polytetrafluoroethylene (Teflon{reg_sign}), polyethylene and cellulose materials. The resulting membrane sheets, under laboratory conditions, were used to evaluate the removal of surrogate radioactive materials for cesium-137 and strontium-90 from high caustic nuclear waste simulants. These membrane supports met the nominal requirement for nonchemical interaction with the embedded ion exchange materials and were porous enough to allow sufficient liquid flow. Some of this 47-mm size stamped out prototype titanium impregnated ion exchange membrane discs was found to remove more than 96% of dissolved cesium-133 and strontium-88 from a caustic nuclear waste salt simulants. Since in traditional ion exchange based column technology monosodium titanate (MST) is known to have great affinity for the sorbing of other actinides like plutonium, neptunium and even uranium, we expect that the MST-based membranes developed here, although not directly evaluated for uptake of these three actinides because of costs associated with working with actinides which do not have 'true' experimental surrogates, would also show significant affinity for these actinides in aqueous media. It was also observed that crystalline silicotitanate impregnated polytetrafluoroethylene or polyethylene membranes became less selective and sorbed both cesium and strontium from the caustic aqueous salt simulants.

Oji, L; Keisha Martin, K; David Hobbs, D

2008-05-30T23:59:59.000Z

71

Permeation of ethylene and ethane through sulfonated polysulfones and sulfonated poly(phenylene oxide) ion exchange membranes  

SciTech Connect

Permeation of ethylene and ethane is sulfonated poly(phenylene oxide), sulfonated bisphenol A polyarylethersulfone and sulfonated hexafluorobisphenol A polyarylethersulfone (6F-SPS) exchanged with Ag{sup +} ions were measured as a function of degree of sulfonation, temperature and trans membrane differential pressure. The data were compared with the permeation results for these membranes in acid form and alkaline metal salt form. Membranes exchanged with Ag{sup +} ions displayed enhanced etylene permeability and ethylene-ethane separation factors. The enhancement in transport of ethylene in ion exchange membranes is apparently related to an increase in ethylene solubility affected by complexation of ethylene with immobilized Ag{sup +} ions. A substantial increase in ethylene permeation rate and separation factor was observed when the feed gas was saturated with water vapors. Enhanced permeation/separation were attributed to an increase in the mobility of silver ions in water plasticized membranes. Membranes plasticized with glycerol exhibited high ethylene permeation rate and ethylene/ethane separation factors in dry feed gas streams that were comparable with permeation rates in water plasticized membranes.

Yurkovetsky, A.; Watterson, A. [Univ. of Massachusetts, Lowell, MA (United States); Bikson, B. [Innovative Membrane Systems, Inc., Norwood, MA (United States); Kharas, G.B. [DePaul Univ., Chicago, IL (United States)

1993-12-31T23:59:59.000Z

72

Metal nanoparticles in catalytic polymer membranes and ion-exchange systems for advanced purification of water from molecular oxygen  

Science Journals Connector (OSTI)

Methods of synthesis of metal nanoparticles and metal/polymer nanocomposites including ion-exchange materials are considered. The effect of the composition and size of nanoparticles on their catalytic activity is analyzed. Attention is focused on the composites used in catalytic processes, namely, catalytic membranes and ion-exchange systems. The problems associated with the removal of dissolved oxygen from water by means of such composites are discussed. The bibliography includes 225 references.

V V Volkov; T A Kravchenko; Vyacheslav I Roldughin

2013-01-01T23:59:59.000Z

73

Proton exchange membrane fuel cells for electrical power generation on-board commercial airplanes.  

SciTech Connect

Deployed on a commercial airplane, proton exchange membrane fuel cells may offer emissions reductions, thermal efficiency gains, and enable locating the power near the point of use. This work seeks to understand whether on-board fuel cell systems are technically feasible, and, if so, if they offer a performance advantage for the airplane as a whole. Through hardware analysis and thermodynamic and electrical simulation, we found that while adding a fuel cell system using today's technology for the PEM fuel cell and hydrogen storage is technically feasible, it will not likely give the airplane a performance benefit. However, when we re-did the analysis using DOE-target technology for the PEM fuel cell and hydrogen storage, we found that the fuel cell system would provide a performance benefit to the airplane (i.e., it can save the airplane some fuel), depending on the way it is configured.

Curgus, Dita Brigitte; Munoz-Ramos, Karina (Sandia National Laboratories, Albuquerque, NM); Pratt, Joseph William; Akhil, Abbas Ali (Sandia National Laboratories, Albuquerque, NM); Klebanoff, Leonard E.; Schenkman, Benjamin L. (Sandia National Laboratories, Albuquerque, NM)

2011-05-01T23:59:59.000Z

74

Proton Exchange Membrane Fuel Cells for Electrical Power Generation On-Board Commercial Airplanes  

NLE Websites -- All DOE Office Websites (Extended Search)

SAND2011-3119 SAND2011-3119 Unlimited Release Printed May 2011 Proton Exchange Membrane Fuel Cells for Electrical Power Generation On-Board Commercial Airplanes Joseph W. Pratt, Leonard E. Klebanoff, Karina Munoz-Ramos, Abbas A. Akhil, Dita B. Curgus, and Benjamin L. Schenkman Prepared by Sandia National Laboratories Albuquerque, New Mexico 87185 and Livermore, California 94550 Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE -AC04-94AL85000. Approved for public release; further dissemination unlimited. Issued by Sandia National Laboratories, operated for the United States Department of Energy

75

Effects of Fabricated Gas Diffusion Layers with Different Reinforce Materials in Proton Exchange Membrane Fuel Cell (PEMFC)  

Science Journals Connector (OSTI)

The anodes and cathodes both consisted of GDL substrate, and the proton exchange membrane consisted of a solid catalyst-coated electrolyte membrane (Gore three-layer CCM MEA with a thickness of 35 ?m; catalyst deposition: cathode, 0.6 mg of Pt/cm2; anode, 0.45 mg of Pt alloy/cm2) in the form of a membrane electrode assembly. ... reaction (ORR) kinetics on Pt catalysts is among the most limiting factors in the energy conversion efficiency of the state-of-the-art PEMFC. ...

Tse-Hao Ko; Yuan-Kai Liao; Ching-Han Liu

2008-09-30T23:59:59.000Z

76

Two-phase flow and transport in the air cathode of proton exchange membrane fuel cells  

SciTech Connect

Two-phase flow and transport of reactants and products in the air cathode of proton exchange membrane (PEM) fuel cells is studied analytically and numerically. Four regimes of water distribution and transport are classified by defining three threshold current densities and a maximum current density. They correspond to first appearance of liquid water at the membrane/cathode interface, extension of the gas-liquid two-phase zone to the cathode/channel interface, saturated moist air exiting the gas channel, and complete consumption of oxygen by the electrochemical reaction. When the cell operates above the first threshold current density, liquid water appears and a two-phase zone forms within the porous cathode. A two-phase, multi-component mixture model in conjunction with a finite-volume-based computational fluid dynamics (CFD) technique is applied to simulate the cathode operation in this regime. The model is able to handle the situation where a single-phase region co-exists with a two-phase zone in the air cathode. For the first time, the polarization curve as well as water and oxygen concentration distributions encompassing both single- and two-phase regimes of the air cathode are presented. Capillary action is found to be the dominant mechanism for water transport inside the two-phase zone. The liquid water saturation within the cathode is predicted to reach 6.3% at 1.4 A/cm{sup 2}.

WANG,Z.H.; WANG,C.Y.; CHEN,KEN S.

2000-03-20T23:59:59.000Z

77

Diagnosis of hydrogen crossover and emission in proton exchange membrane fuel cells  

Science Journals Connector (OSTI)

Abstract When hydrogen leaks through holes in membrane-electrode assemblies (MEAs) in proton exchange membrane (PEM) fuel cells, it recombines directly with air. This recombination results in a reduction in oxygen concentration on the cathode side of the MEA. In this paper, the signatures of electrochemical impedance spectroscopy (EIS) are analyzed in different multi-cell stack configurations to show the relation between hydrogen leak rate and reduced oxygen concentrations. The reduction in concentration was made by mixing oxygen with nitrogen at different rates, and the increase in hydrogen leak rate was made by controlling the differential pressure (dP) between anode and cathode. To analyze the impedance signatures, we fit the data of oxygen concentration and dP with the parameters of a Randles circuit. The correlation between the parameters of the two data sets allows us to understand the change in impedance signatures with respect to reduction of oxygen in the cathode side. To have a better insight on the effect of insufficient oxygen at the cathode, a model that establishes a relationship between impedance and voltage was considered. Using this model along with the impedance signatures we were able to detect the reduction of oxygen concentrations at the cathode with the help of fuzzy rule-base. However, resolution of detection was reduced with the reduction of leak rate and/or increases in the stack cell count.

G. Mousa; J. DeVaal; F. Golnaraghi

2014-01-01T23:59:59.000Z

78

Diagnosis of hydrogen crossover and emission in proton exchange membrane fuel cells  

Science Journals Connector (OSTI)

Abstract When hydrogen leaks through holes or cracks in membrane-electrode assemblies (MEAs) in Proton Exchange Membrane (PEM) fuel cells, it recombines directly with air. This recombination results in a reduction in oxygen concentration on the cathode side of the MEA. In this paper, the signatures of electrochemical impedance spectroscopy (EIS) are analyzed in different multi-cell stack configurations to show the relation between hydrogen leak rate and reduced oxygen concentrations. The reduction in concentration was made by mixing oxygen with nitrogen at different rates, and the increase in hydrogen leak rate was made by controlling the differential pressure (dP) between anode and cathode. To analyze the impedance signatures, we fit the data of oxygen concentration and dP with the parameters of a Randles circuit. The correlation between the parameters of the two data sets allows us to understand the change in impedance signatures with respect to reduction of oxygen in the cathode side. To have a better insight on the effect of insufficient oxygen at the cathode, a model that establishes a relationship between impedance and voltage was considered. Using this model along with the impedance signatures we were able to detect the reduction of oxygen concentrations at the cathode with the help of fuzzy rule-base. However, resolution of detection was reduced with the reduction of leak rate and/or increases in the stack cell count.

G. Mousa; J. DeVaal; F. Golnaraghi

2014-01-01T23:59:59.000Z

79

Performance Analysis of a Proton-Exchange Membrane Fuel Cell (PEMFC) with Various Hydrophobic Agents in a Gas Diffusion Layer  

Science Journals Connector (OSTI)

The microporous layer (MPL) between the carbon cloth and catalyst layer is a significant part in a proton-exchange membrane fuel cell (PEMFC). ... The electrode is treated with sufficient water-resistant additive to enable it to be used as a cathode in a PEMFC. ...

Jui-Hsiang Lin; Wei-Hung Chen; Yen-Ju Su; Tse-Hao Ko

2008-02-14T23:59:59.000Z

80

Interim report re: component parts for proton-exchange membrane fuel cells  

SciTech Connect

The purpose of the first phase of the grant project is to design, develop and test a simplified fuel cell electrode structure for use in proton-exchange membrane fuel cells (''PEMFC''). By simplifying the structure of the electrode, mass production manufacturing efficiencies can be brought into play which will result in significant cost reductions for this fuel cell component. With a reduction in the cost of this key fuel cell component overall costs for PEMFC's can be brought within the commercialization target range of about US$100 per kilowatt for the fuel cell stack. Fuel cell electrodes are necessarily ''multi-layered'' composites. Multi-layers are required because of the several functions that the electrode must be able to perform in the working PEM fuel cell. The current generation of state-of-the-art porous fuel cell electrodes for PEMFC's is comprised of three primary layers. The first layer is the catalyst layer. Since hydrogen is the fuel used in this project and air is used as the oxidant, the catalyst must be capable of adsorbing hydrogen and oxygen from the air. While work is constantly on-going with respect to new hydrogen or oxygen catalysts, the best available catalyst at present for both of the reactant gases is platinum. To be effective, the catalyst (1) must be exposed to a constant flow of the respective reactant gas; (2) must be in intimate contact with the proton-exchange membrane; and (3) must be a finely divided catalyst and have a large specific surface area, especially on the oxidant side where the electrochemical reaction is slower by several orders of magnitude. The second layer is the substrate layer. The substrate layer provides structural support for the finely divided catalyst. It also functions as an electronic junction for conducting electricity produced by the electrochemical reaction from the catalyst layer to the bipolar plate of the fuel cell. In state-of-the-art PEMFC's, this layer is comprised of carbon particles (onto which the catalyst has been deposited) and a binder material. In Dr. Mahlon Wilson's fuel cell electrode design, the binder material is liquid Nafion. By using liquid Nafion, the membrane is effectively extended into a third spatial dimension. This extension of the membrane serves to increase the effective catalyst surface area per real geometric unit of fuel cell area, which is quite important for the reasons discussed above. In the more traditional Los Alamos design, the binder is liquid Teflon, which is mixed with the catalyzed carbon particles and then sintered to create hydrophobic gas pores in the substrate layer. In order to extend the membrane into a third spatial dimension with this type of electrode, liquid Nafion is then applied to the substrate and allowed to seep through the sintered Teflon pores into the substrate/catalyst layer. The third layer is the backing layer. The backing layer is normally comprised of either carbon cloth or porous carbon paper. The purpose of the backing layer is (1) to conduct electricity generated by the electrochemical reaction; (2) to provide structural support for the substrate layer and (3) to allow the reactant gases to enter and leave the substrate/catalyst layers. Thus, in state-of-the-art fuel cell electrode design, the electrode is a ''triple layer composite'', consisting of the catalyst layer, the substrate layer and the backing layer. The triple layer composite electrode, when hot-pressed to the proton-exchange membrane, is strong enough to prevent the membrane from expanding in the localized area of the fuel cell electrode. This strength is significant because membrane expansion could otherwise damage the electrode and adversely affect its electronic conductivity. While triple layer composite electrodes function well, their structure does not readily lend itself to mass production. Consequently, fuel cell electrodes are extremely expensive to manufacture. For example, E-Tek of Natrick, Massachusetts, the leading manufacturer of fuel cell electrodes in this country, has quoted a mass production price of $0.30 per s

George Marchetti

1999-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

HOGEN{trademark} proton exchange membrane hydrogen generators: Commercialization of PEM electrolyzers  

SciTech Connect

PROTON Energy Systems` new HOGEN series hydrogen generators are Proton Exchange Membrane (PEM) based water electrolyzers designed to generate 300 to 1000 Standard Cubic Feet Per Hour (SCFH) of high purity hydrogen at pressures up to 400 psi without the use of mechanical compressors. This paper will describe technology evolution leading to the HOGEN, identify system design performance parameters and describe the physical packaging and interfaces of HOGEN systems. PEM electrolyzers have served US and UK Navy and NASA needs for many years in a variety of diverse programs including oxygen generators for life support applications. In the late 1970`s these systems were advocated for bulk hydrogen generation through a series of DOE sponsored program activities. During the military buildup of the 1980`s commercial deployment of PEM hydrogen generators was de-emphasized as priority was given to new Navy and NASA PEM electrolysis systems. PROTON Energy Systems was founded in 1996 with the primary corporate mission of commercializing PEM hydrogen generators. These systems are specifically designed and priced to meet the needs of commercial markets and produced through manufacturing processes tailored to these applications. The HOGEN series generators are the first step along the path to full commercial deployment of PEM electrolyzer products for both industrial and consumer uses. The 300/1000 series are sized to meet the needs of the industrial gases market today and provide a design base that can transition to serve the needs of a decentralized hydrogen infrastructure tomorrow.

Smith, W.F.; Molter, T.M. [Proton Energy Systems, Inc., Rocky Hill, CT (United States)

1997-12-31T23:59:59.000Z

82

Study on hydrophobicity degradation of gas diffusion layer in proton exchange membrane fuel cells  

Science Journals Connector (OSTI)

Abstract As one of the essential components of proton exchange membrane fuel cell (PEMFC), gas diffusion layer (GDL) is of importance on water management, as well on the performance and durability of PEMFC. In this paper, the hydrophobicity degradation of GDL was investigated by immersing it in the 1.0 mol L?1 H2SO4 solution saturated by air for 1200 h. From the measurements of contact angle and water permeability, the hydrophobic characteristics of the pristine and immersed \\{GDLs\\} were compared. To investigate the causes for hydrophobicity degradation, the \\{GDLs\\} were analyzed by scanning electron microscopy, X-ray photoelectron spectroscopy and thermogravimetry. Further, the chemical compositions of H2SO4 solutions before and after immersion test were analyzed with infrared spectroscopy. Results showed that the hydrophobicity of immersed GDL decreased distinctly, which was caused by the damage of physical structure and surface characteristics. Moreover, the immersed GDL showed a worse fuel cell performance than the pristine GDL, especially under a low humidity condition.

Shuchun Yu; Xiaojin Li; Jin Li; Sa Liu; Wangting Lu; Zhigang Shao; Baolian Yi

2013-01-01T23:59:59.000Z

83

Protective nitride formation on stainless steel alloys for proton exchange membrane fuel cell bipolar plates  

SciTech Connect

Gas nitridation has shown excellent promise to form dense, electrically conductive and corrosion-resistant Cr-nitride surface layers on Ni-Cr base alloys for use as proton exchange membrane fuel cell (PEMFC) bipolar plates. Due to the high cost of nickel, Fe-base bipolar plate alloys are needed to meet the cost targets for many PEMFC applications. Unfortunately, nitridation of Fe-base stainless steel alloys typically leads to internal Cr-nitride precipitation rather than the desired protective surface nitride layer formation, due to the high permeability of nitrogen in these alloys. This paper reports the finding that it is possible to form a continuous, protective Cr-nitride (CrN and Cr{sub 2}N) surface layer through nitridation of Fe-base stainless steel alloys. The key to form a protective Cr-nitride surface layer was found to be the initial formation of oxide during nitridation, which prevented the internal nitridation typically observed for these alloys, and resulted in external Cr-nitride layer formation. The addition of V to the alloy, which resulted in the initial formation of V{sub 2}O{sub 3}-Cr{sub 2}O{sub 3}, was found to enhance this effect, by making the initially formed oxide more amenable to subsequent nitridation. The Cr-nitride surface layer formed on model V-modified Fe-27Cr alloys exhibited excellent corrosion resistance and low interfacial contact resistance under simulated PEMFC bipolar plate conditions.

Yang, Bing [ORNL; Brady, Michael P [ORNL; Wang, Heli [National Renewable Energy Laboratory (NREL); Turner, John [National Renewable Energy Laboratory (NREL); More, Karren Leslie [ORNL; Young, David J [ORNL; Tortorelli, Peter F [ORNL; Payzant, E Andrew [ORNL; Walker, Larry R [ORNL

2007-01-01T23:59:59.000Z

84

ESS 2012 Peer Review - Novel Regenerative Fuel Cells based on Anion Exchange Membranes - Katherine Ayers, Proton Onsite  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

l l R ti F l C ll b d A i E h M b f Novel Regenerative Fuel Cells based on Anion Exchange Membranes for Novel Regenerative Fuel Cells based on Anion Exchange Membranes for g g Affordable Renewable Energy Storage Affordable Renewable Energy Storage Affordable Renewable Energy Storage PI: Dr Katherine Ayers Proton Energy Systems kayers@protononsite com PI: Dr. Katherine Ayers, Proton Energy Systems, kayers@protononsite.com y , gy y , y @p A h Key Challenges and Progress Approach Key Challenges and Progress Approach Key Challenges and Progress pp N PGM t l t ( l t l ) Fuel Cell Durability: Non-PGM catalysts (electrolyzer) * Leverage Proton experience in large scale Fuel Cell Durability: o G cata ysts (e ect o y e ) * Leverage Proton experience in large scale Anode flooding and cathode * Translation from RDE to cell results electrolysis and regenerative fuel

85

Proton exchange membrane water electrolysis with short-side-chain Aquivion® membrane and IrO2 anode catalyst  

Science Journals Connector (OSTI)

Abstract A series of three membrane types has been screened for medium temperature solid polymer electrolyte water electrolysis in membrane electrode assemblies coated with 2 mg cm?2 of iridium oxide as a catalyst for the oxygen evolution reaction, synthesised via a hydrolysis method from the hexachloroiridic acid precursor, and deposited on the membrane either directly by spray deposition or by decal transfer. The short-side-chain perfluorosulfonic acid Aquivion® ionomer of equivalent weight 870 meq g?1, in membranes of thickness 120 ?m, gives higher water electrolysis performance at 120 °C than a composite membrane of Aquivion® with zirconium phosphate, while a sulfonated ether-linked polybenzimidazole, sulfonated poly-[(1-(4,4?-diphenylether)-5-oxybenzimidazole)-benzimidazole], shows promising performance and no transport limitations up to 2 A cm?2. The lowest cell voltage was observed at 120 °C for an MEA prepared using spray-coating directly on the Aquivion® membrane, 1.57 V at 1 A cm?2.

Anita Skulimowska; Marc Dupont; Marta Zaton; Svein Sunde; Luca Merlo; Deborah J. Jones; Jacques Rozière

2014-01-01T23:59:59.000Z

86

Effect of direct liquid water injection and interdigitated flow field on the performance of proton exchange membrane fuel cells  

E-Print Network (OSTI)

70-108B One Cyclotron Road Berkeley, California 94720 December 2, 1997 Key Words: Proton Exchange Membrane fuel cells, humidification, gas distribution, direct liquid water injection, interdigitated flow fields. * Corresponding... of the catalyst layers were made of waterproof, carbon fiber cloths. Liquid water was injected by two metering pumps into two heated stainless steel coils, where it was preheated to the cell operating temperatures, and then directly into the gas streams...

Wood, D. L.; Yi, Y. S.; Nguyen, Trung Van

1998-01-01T23:59:59.000Z

87

Pt Nanoparticle-Dispersed Graphene-Wrapped MWNT Composites As Oxygen Reduction Reaction Electrocatalyst in Proton Exchange Membrane Fuel Cell  

Science Journals Connector (OSTI)

The rapid devastation of nonrenewable energy sources demanded the development of alternative energy conversion devices such as fuel cells with high efficiency and environmental benignity. ... (1-3) The commercialization of proton exchange membrane fuel cell (PEMFC) is still not achieved because of the high cost of the electrocatalyst, platinum (Pt). ... Carbon supported electrocatalysts have been found to be effective in reducing the amount of platinum and enhancing the PEMFC performance. ...

S. S. Jyothirmayee Aravind; Sundara Ramaprabhu

2012-08-01T23:59:59.000Z

88

Degradation of proton exchange membrane by Pt dissolved/deposited in fuel cells  

Science Journals Connector (OSTI)

An accelerated single cell test and single electrode cell test were carried out to investigate membrane degradation by Pt dissolved/deposited on the membrane. For a cell operating under accelerated conditions ...

Taehee Kim; Ho Lee; Woojong Sim; Jonghyun Lee…

2009-09-01T23:59:59.000Z

89

Mass transfer and kinetic phenomena at the nickel hydroxide electrode  

SciTech Connect

Thin-film (10 to 40 nm thickness) nickel hydroxide intercalation electrodes were constructed using an electroprecipitation technique. Cyclic voltammetry, potentiostatic step, and galvanostatic discharge experiments were performed and interpreted in terms of a macroscopic model treating the simultaneous mass transfer, kinetic, and thermodynamic phenomena occurring within the cell. The side reaction, oxygen evolution, exhibited irreversible Tafel behavior, with a proton concentration-dependent exchange current density of 4.5 {times} 10{sup {minus}9} [(c{sub 0} {minus} c)/c{sub 0}] A/cm{sup 2} on pure nickel hydroxide films, and a constant exchange current density of 4.5 {times} 10{sup {minus}9} A/cm{sup 2} on cobalt hydroxide-containing nickel hydroxide films. The apparent anodic transfer coefficient for the oxygen reaction is 0.49 on pure nickel hydroxide films and 0.42 on cobalt hydroxide-containing nickel hydroxide films. The apparent anodic transfer coefficient for the oxygen reaction is 0.49 on pure nickel hydroxide films and 0.42 on cobalt hydroxide-containing nickel hydroxide films. The intercalation reaction is described with a Butler-Volmer-type expression with a large, proton concentration-dependent exchange current density of 9.5 {times} 10{sup {minus}2} [c(c{sub 0} {minus} c)]{sup 1/2} A/cm{sup 2}, and anodic and cathodic apparent transfer coefficients of 0.5 for both electrode types. Here c and c{sub 0} have units of mol/cm{sup 3}. The proton diffusion coefficient in pure nickel hydroxide was found to depend on the proton concentration, with values ranging from 1.2 {times} 10{sup {minus}13} to 1.9 {times} 10{sup {minus}12} cm{sup 2}/s, with a concentration-averaged value of 3.417 {times} 10{sup {minus}13} cm{sup 2}/s. In cobalt hydroxide-containing nickel hydroxide, the values ranged from 2 {times} 10{sup {minus}13} to 1.9 {times} 10{sup {minus}12} cm{sup 2}/s, with a concentration-averaged value of 8.402 {times} 10{sup {minus}13} cm{sup 2}/s.

Ta, K.P.; Newman, J. [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technologies Div.]|[Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering

1998-11-01T23:59:59.000Z

90

A thin-film/agglomerate model of a proton-exchange-membrane fuel cell cathode catalyst layer with consideration of solid-polymer-electrolyte distribution  

Science Journals Connector (OSTI)

Experimental work on the proton-exchange-membrane fuel cell (PEMFC) has revealed that a better utilization of carbon supported platinum catalyst (Pt/C) hinges on an appropriate...1–12...]. GDE is prepared by a po...

Ken-Ming Yin

2007-08-01T23:59:59.000Z

91

Performance Degradation of TiN-and TiC-deposited AISI316 bipolar plates for proton exchange membrane fuel cells  

Science Journals Connector (OSTI)

TiN and TiC were deposited on AISI316 bipolar plates for proton exchange membrane fuel cells (PEMFCs) and their effects on the corrosion resistance and overall cell performance were investigated. TiN with a Ti...

Hee Yeol Lee; Jae Woong Choi; Gil Ho Hwang…

2006-04-01T23:59:59.000Z

92

Conceptual design report for a Direct Hydrogen Proton Exchange Membrane Fuel Cell for transportation application  

SciTech Connect

This report presents the conceptual design for a Direct-Hydrogen-Fueled Proton Exchange Membrane (PEM) Fuel Cell System for transportation applications. The design is based on the initial selection of the Chrysler LH sedan as the target vehicle with a 50 kW (gross) PEM Fuel Cell Stack (FCS) as the primary power source, a battery-powered Load Leveling Unit (LLU) for surge power requirements, an on-board hydrogen storage subsystem containing high pressure gaseous storage, a Gas Management Subsystem (GMS) to manage the hydrogen and air supplies for the FCS, and electronic controllers to control the electrical system. The design process has been dedicated to the use of Design-to-Cost (DTC) principles. The Direct Hydrogen-Powered PEM Fuel Cell Stack Hybrid Vehicle (DPHV) system is designed to operate on the Federal Urban Driving Schedule (FUDS) and Hiway Cycles. These cycles have been used to evaluate the vehicle performance with regard to range and hydrogen usage. The major constraints for the DPHV vehicle are vehicle and battery weight, transparency of the power system and drive train to the user, equivalence of fuel and life cycle costs to conventional vehicles, and vehicle range. The energy and power requirements are derived by the capability of the DPHV system to achieve an acceleration from 0 to 60 MPH within 12 seconds, and the capability to achieve and maintain a speed of 55 MPH on a grade of seven percent. The conceptual design for the DPHV vehicle is shown in a figure. A detailed description of the Hydrogen Storage Subsystem is given in section 4. A detailed description of the FCS Subsystem and GMS is given in section 3. A detailed description of the LLU, selection of the LLU energy source, and the power controller designs is given in section 5.

NONE

1995-09-05T23:59:59.000Z

93

Carbon Corrosion in Proton-Exchange Membrane Fuel Cells: From Model Experiments to Real-Life Operation in Membrane Electrode Assemblies  

Science Journals Connector (OSTI)

Those changes are in perfect agreement with what was observed on the model PEMFC electrocatalyst during the 96-h polarization (see TEM images, Pt particle size distribution, and the variation of the mean Pt particle size in Figure S6, Figure S7, and Table S1 of the SI). ... Pt/HSAC electrocatalysts, and mean cell voltage (calculated on the 110 cells) during the 12,860 h PEMFC aging test. ... The research and development of catalysts with high activity and high durability is a significant issue for proton exchange membrane fuel cell (PEMFC). ...

Luis Castanheira; Laetitia Dubau; Michel Mermoux; Gregory Berthomé; Nicolas Caqué; Elisabeth Rossinot; Marian Chatenet; Frédéric Maillard

2014-06-13T23:59:59.000Z

94

Dr. Ing. /PhD / Dr.techn. Students supervised by Signe Kjelstrup 1. Torleif Holt, Transport and equilibrium properties of a cation exchange membrane (1983)  

E-Print Network (OSTI)

, (1996) 6. Magnar Ottøy, Mass and heat transfer in ion-exchange membranes (1996) 7. Belinda Flem, Peltier in the Polymer Electrolyte Membrane Fuel Cell (2007) 17. Isabella Inzoli, Coupled transports of heat and massDr. Ing. /PhD / Dr.techn. Students supervised by Signe Kjelstrup 1. Torleif Holt, Transport

Kjelstrup, Signe

95

Oxygen diffusion, surface exchange and oxygen semi-permeation performances of Ln2NiO4+ membranes (Ln = La, Pr and Nd)  

E-Print Network (OSTI)

Oxygen diffusion, surface exchange and oxygen semi-permeation performances of Ln2NiO4+ membranes the rate determining step (rds) in oxygen semi-permeation of dense Ln2NiO4+ membranes (with Ln = La, Pr and Nd), a specific setup has been designed, which allowed measuring the oxygen semi-permeation flux

Paris-Sud XI, Université de

96

Hydroxide absorption heat pumps with spray absorber  

SciTech Connect

The absorber is one of the most expensive components of an absorption heat pump or chiller, respectively. In order to reduce the cost of a heat exchanger, much effort is invested into searching for additives for heat transfer enhancement. Another way to reduce heat exchanger cost, especially for machines with low capacities, is to use an adiabatic spray absorber. The basic principles of the spray absorber is to perform heat and mass transfer separated from each other in two different components. In this way the heat can be rejected effectively in a liquid-liquid heat exchanger, whereas the mass transfer occurs subsequently in a simple vessel. The spray technique can not only save heat exchanger cost in conventional absorption systems working with water and lithium bromide, it also allows the use of quite different working fluids such as hydroxides, which have lower heat transfer coefficients in falling films. Moreover, the separated heat transfer can easily be performed in a liquid-to-air heat exchanger. Hence it is obvious to use hydroxides that allow for a high temperature lift for building an air-cooled chiller with spray absorber. In this presentation theoretical and experimental investigations of the spray absorber as well as the setup will be described. Finally, possible applications will be outlined.

Summerer, F.; Alefeld, G. [Technische Univ. Muenchen, Munich (Germany). Physics Dept.; Zeigler, F.; Riesch, P. [Bayerisches Zentrum fuer Angewandte Energieforschung, Munich (Germany)

1996-11-01T23:59:59.000Z

97

The Investigation and Development of Low Cost Hardware Components for Proton-Exchange Membrane Fuel Cells - Final Report  

SciTech Connect

Proton exchange membrane (PEM) fuel cell components, which would have a low-cost structure in mass production, were fabricated and tested. A fuel cell electrode structure, comprising a thin layer of graphite (50 microns) and a front-loaded platinum catalyst layer (600 angstroms), was shown to produce significant power densities. In addition, a PEM bipolar plate, comprising flexible graphite, carbon cloth flow-fields and an integrated polymer gasket, was fabricated. Power densities of a two-cell unit using this inexpensive bipolar plate architecture were shown to be comparable to state-of-the-art bipolar plates.

George A. Marchetti

1999-12-15T23:59:59.000Z

98

The characteristics of voltage degradation of a proton exchange membrane fuel cell under a road operating environment  

Science Journals Connector (OSTI)

Abstract A real-life testing experiment of a proton exchange membrane fuel cell (PEMFC) and the basic characteristics of its voltage degradation are presented. A general package radio system (GPRS)-based remote monitoring system was used as the data acquisition method, and the non-linear regression method was used to estimate PEMFC's polarization curve within specific iso-interval periods. The voltage degradation rate was calculated using the differential method, and its average level was also analyzed. The experimental results indicated that the voltage degradation rate at a specific current density featured a bathtub-like curve, exhibiting 1) infant degradation, 2) steady degradation, 3) and accelerated degradation.

Xinfeng Zhang; Yang Rui; Zhang Tong; Xu Sichuan; Shen Yong; Ni Huaisheng

2014-01-01T23:59:59.000Z

99

FUEL CELLS – PROTON-EXCHANGE MEMBRANE FUEL CELLS | High-Temperature PEMFC  

Science Journals Connector (OSTI)

Abstract For various applications, higher temperature levels compared to the temperature level of classical polymer electrolyte membrane fuel cells (PEMFCs) with low-temperature membrane are favorable. The motivation for the development of this new type of \\{PEMFCs\\} with high-temperature membrane are easy water management and smaller, more compact cooling systems. Additionally, the electrocatalyst shows a better CO tolerance at higher temperature. In fuel cell systems with a reformer, no fine purification reactor is needed anymore. Applications with a high added value due to these criteria can be found in portable, in mobile as well as in stationary applications.

A. Heinzel; G. Bandlamudi; W. Lehnert

2014-01-01T23:59:59.000Z

100

Investigation of dynamic driving cycle effect on the degradation of proton exchange membrane fuel cell by segmented cell technology  

Science Journals Connector (OSTI)

Abstract Durability is one of the most important limiting factors for the commercialization of proton exchange membrane fuel cell (PEMFC). Fuel cells are more vulnerable to degradation under operating conditions as dynamic load cycle or start up/shut down. The purpose of this study is to evaluate influences of driving cycles on the durability of fuel cells through analyzing the degradation mechanism of a segmented cell in real time. This study demonstrates that the performance of the fuel cell significantly decreases after 200 cycles. The segmented cell technology is used to measure the local current density distribution, which shows that the current density at the exit region and the inlet region declines much faster than the other parts. Meanwhile, electro-chemical impedance spectroscopy (EIS) reveals that after 200 cycles the ohmic resistance of fuel cell increases, especially at the cathode, and electro-chemical surface area (ESA) decreases from 392 to 307 cm2 mg?1. Furthermore, scanning electron microscopy (SEM) images of the membrane–electrode assembly (MEA) in cross-section demonstrate crackle flaw on the surface of the catalyst layer and the delamination of the electrodes from the membrane. Transmission electron microscope (TEM) results also show that the Pt particle size increases distinctly after driving cycles.

R. Lin; F. Xiong; W.C. Tang; L. Técher; J.M. Zhang; J.X. Ma

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Haemocompatibility and ion exchange capability of nanocellulose polypyrrole membranes intended for blood purification  

Science Journals Connector (OSTI)

...highly purified water. The increasing...haemodialysis membranes and dialysis technology that...following groups: small water-soluble compounds...difficult to remove by dialysis. The failure to...during dialysis treatments [1]. However...extraction [11] and electric energy storage...

2012-01-01T23:59:59.000Z

102

Perchlorate Degradation Using Partially Oxidized Titanium Ions and Ion Exchange Membrane Hybrid System  

E-Print Network (OSTI)

. To enhance the overall rate of reaction, high concentrations of acid and Ti(III) are needed, but transport of hydrogen ions through the anion permeable membrane was observed and would be greater at higher acid concentrations. The proposed mathematical model...

Park, Sung Hyuk

2011-08-08T23:59:59.000Z

103

Measurements of water uptake and transport properties in anion-exchange membranes  

E-Print Network (OSTI)

, the electro-osmotic drag (EOD) coefficient, and the mass-transfer coefficient of water at the cathode catalyst/membrane interface falls in the range of 1.0 Ã? 10Ã?6 to 1.0 Ã? 10Ã?5 m sÃ?1 . The EOD coefficients measured at 30 C

Zhao, Tianshou

104

Highly Stable and CO-Tolerant Pt/Ti0.7W0.3O2 Electrocatalyst for Proton-Exchange Membrane Fuel Cells  

Science Journals Connector (OSTI)

Overview of the development of CO-tolerant anode electrocatalysts for proton-exchange membrane fuel cells ... Based on literature starting in 2000, a few efforts have still been conducted at developing a more CO-tolerant anode electrocatalyst than the traditional Pt/C or PtRu/C systems. ... The performance of proton exchange membrane fuel cells (PEMFC) fed with CO-contaminated hydrogen was studied for anodes with PtWOx/C and phosphotungstic acid (PTA) impregnated Pt/C electrocatalysts. ...

Deli Wang; Chinmayee V. Subban; Hongsen Wang; Eric Rus; Francis J. DiSalvo; Hector D. Abruña

2010-07-12T23:59:59.000Z

105

Ammonium Bicarbonate Transport in Anion Exchange Membranes for Salinity Gradient Energy  

E-Print Network (OSTI)

such as reverse electrodialysis (RED) rely on highly selective anion transport through polymeric anion exchange to address global energy needs, such as reverse electro- dialysis1-4 (RED), capacitive energy extraction based on Donnan potential5 (CDP), and capacitive reverse electro- dialysis6 (CRED), has encouraged

106

Calcium hydroxide pretreatment of biomass  

E-Print Network (OSTI)

HYDROXIDE RECOVERY DATA. . . . . . 135 138 142 . . . . . 148 . . . . . 150 . . . . . 153 156 LIST OF TABLES Table Page 1. Methods used for pretreatment of lignocellulosics. . . . . . . . 15 2. Ammoniation conditions used by previous workers...C-pH diagram for a carbonate solution. 32 12. Flow diagram for continuous calcium hydroxide recovery. . . 13. A tree of possible experimental conditions. . . . . . . . . . . . . . . . . . 14. Sugar yields obtained from ammoniated bagasse...

Nagwani, Murlidhar

1992-01-01T23:59:59.000Z

107

Pt/SWNT?Pt/C Nanocomposite Electrocatalysts for Proton-Exchange Membrane Fuel Cells  

Science Journals Connector (OSTI)

The dependence of the fuel cell performance on the dispersion and accessibility of SWNT support and Pt electrocatalysts in the electrocatalyst mixture for the oxygen reduction reaction in PEMFC has been discussed. ... Further, in PEMFC, most of the recent work is being focused on the development of cathode electrocatalyst materials. ... to 500-800°, and reducing PEMFC system complexity be developing 'water-free' membranes which can also be operated at temps. ...

A. Leela Mohana Reddy; S. Ramaprabhu

2007-10-17T23:59:59.000Z

108

Investigating the effects of proton exchange membrane fuel cell conditions on carbon supported platinum electrocatalyst composition and performance  

SciTech Connect

Changes that carbon-supported platinum electrocatalysts undergo in a proton exchange membrane fuel cell environment were simulated by ex situ heat treatment of catalyst powder samples at 150 #2;C and 100% relative humidity. In order to study modifications that are introduced to chemistry, morphology, and performance of electrocatalysts, XPS, HREELS and three-electrode rotating disk electrode experiments were performed. Before heat treatment, graphitic content varied by 20% among samples with different types of carbon supports, with distinct differences between bulk and surface compositions within each sample. Following the aging protocol, the bulk and surface chemistry of the samples were similar, with graphite content increasing or remaining constant and Pt-carbide decreasing for all samples. From the correlation of changes in chemical composition and losses in performance of the electrocatalysts, we conclude that relative distribution of Pt particles on graphitic and amorphous carbon is as important for electrocatalytic activity as the absolute amount of graphitic carbon present

Patel, Anant; Artyushkova, Kateryna; Atanassov, Plamen; Colbow, Vesna; Dutta, Monica; Harvey, Davie; Wessel, Silvia

2012-04-01T23:59:59.000Z

109

Ordered Hierarchical Nanostructured Carbon as a Highly Efficient Cathode Catalyst Support in Proton Exchange Membrane Fuel Cell  

Science Journals Connector (OSTI)

Ordered hierarchical nanostructured carbon (OHNC) has been fabricated through inverse replication of silica template and explored for the first time to support high loading of Pt nanoparticles as cathode catalyst in proton exchange membrane fuel cells (PEMFC). ... Ordered porous carbon materials with three-dimensionally interconnected pore structures and highly developed porosity have a variety of potential applications such as catalyst supports in low temperature fuel cells,(1, 2) electrode materials for electric double-layer capacitors(3, 4) and for lithium ion batteries,(5) adsorbents, and hydrogen storage materials. ... Carbon black Vulcan XC-72 (VC) is widely used as an electrocatalyst support in the PEMFCs due to its relatively large surface area and excellent chemical stability in the fuel cell environment. ...

Baizeng Fang; Jung Ho Kim; Minsik Kim; Jong-Sung Yu

2009-02-04T23:59:59.000Z

110

Low platinum, high limiting current density of the PEMFC (proton exchange membrane fuel cell) based on multilayer cathode catalyst approach  

Science Journals Connector (OSTI)

Abstract Novel multilayer cathode electrodes structures for PEMFC (proton exchange membrane fuel cell) based on sputtering technique were developed to provide high performance with low loading Pt of 0.05 mg/cm² compared to the standard MEA (membrane electrode assembly) cathode (?0.2–0.3 mg/cm²). Different configurations of cathode catalyst layer were made by altering Pt and CN (Carbon–Nafion) ink carefully prepared on gas diffusion layer containing MPL (micro porous layer). The performances of PEMFC containing the multilayer electrodes were compared based on their measured polarization curves. Higher limiting current densities were achieved compared to standard MEA with platinum loading of 0.2 mg/cm² both at the cathode and the anode sides. Limiting current densities over 1.1 A/cm2, 1.2 A/cm2 and 1.4 A/cm2 were reached whereas maximum powers were in the range of 500 mW/cm² at 600 mW/cm². The good performances obtained can be due to the structural improvement which has contributed to a better catalyst utilization compared to conventional methods. A CN loading inferior to 0.24 mg/cm² between each layer is preferred for multilayer electrode.

Daouda Fofana; Sadesh Kumar Natarajan; Jean Hamelin; Pierre Benard

2014-01-01T23:59:59.000Z

111

Performance data of a proton exchange membrane fuel cell using H{sub 2}/CO as fuel gas  

SciTech Connect

The performance of a proton exchange membrane fuel cell (PEMFC) was evaluated at 80 C in H{sub 2} with defined amounts of CO (25 to 250 ppm) and pure oxygen. Membrane electrode assemblies (MEAs) were made using Nafion{trademark} 117 with carbon-supported dispersed Pt, Pt{sub 0.7}Ru{sub 0.3}, and Pt{sub 0.5}Ru{sub 0.5} as anode catalysts, and Pt as a cathode catalyst. For comparison the MEAs were first characterized in H{sub 2}/O{sub 2}. In H{sub 2}/CO//O{sub 2} steady-state current-voltage curves were obtained after a poisoning period. It was found that the performance of the cell depends strongly on the CO concentration and the anode catalyst used. For Pt{sub 0.5}Ru{sub 0.5} as anode catalyst, the maximum power density in H{sub 2}/CO//O{sub 2} was enhanced by a factor of four compared with a Pt anode catalyst. Using Pt{sub 0.5}Ru{sub 0.5} no difference in power density was found between pure H{sub 2} and H{sub 2}/100 ppm CO up to current densities of about 0.4 cm{sup {minus}2}.

Oetjen, H.F.; Schmidt, V.M.; Stimming, U.; Trila, F. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Energieverfahrenstechnik

1996-12-01T23:59:59.000Z

112

Proton exchange membrane fuel cells with chromium nitride nanocrystals as electrocatalysts  

Science Journals Connector (OSTI)

Polymer electrolyte membrane fuel cells(PEMFCs) are energy conversion devices that produce electricity from a supply of fuel such as hydrogen. One of the major challenges in achieving efficient energy conversion is the development of cost-effective materials that can act as electrocatalysts for PEMFCs. In this letter we demonstrate that instead of conventional noble metals such as platinum chromium nitride nanocrystals of fcc structure exhibit attractive catalytic activity for PEMFCs. Device testing indicates good stability of nitride nanocrystals in low temperature fuel cell operational environment.

Hexiang Zhong; Xiaobo Chen; Huamin Zhang; Meiri Wang; Samuel S. Mao

2007-01-01T23:59:59.000Z

113

Effective Transport Properties Accounting for Electrochemical Reactions of Proton-Exchange Membrane Fuel Cell Catalyst Layers  

SciTech Connect

There has been a rapidly growing interest in three-dimensional micro-structural reconstruction of fuel cell electrodes so as to derive more accurate descriptors of the pertinent geometric and effective transport properties. Due to the limited accessibility of experiments based reconstruction techniques, such as dual-beam focused ion beam-scanning electro microscopy or micro X-Ray computed tomography, within sample micro-structures of the catalyst layers in polymer electrolyte membrane fuel cells (PEMFCs), a particle based numerical model is used in this study to reconstruct sample microstructure of the catalyst layers in PEMFCs. Then the reconstructed sample structure is converted into the computational grid using body-fitted/cut-cell based unstructured meshing technique. Finally, finite volume methods (FVM) are applied to calculate effective properties on computational sample domains.

Pharoah, Jon; Choi, Hae-Won; Chueh, Chih-Che; Harvey, David

2011-07-01T23:59:59.000Z

114

Two-dimensional NMR spectroscopy reveals cation-triggered backbone degradation in polysulfone-based anion exchange membranes  

Science Journals Connector (OSTI)

...Alkaline Membrane Fuel Cell Workshop final report: Proceedings from the Alkaline Membrane Fuel Cell Workshop. Available at www1.eere.energy.gov/hydrogenandfuelcells/wkshp_alkaline_membrane.html, pp 1–28. Accessed August 7, 2012 . 6 Pletcher...

Christopher G. Arges; Vijay Ramani

2013-01-01T23:59:59.000Z

115

Characterization of proton exchange membrane materials for fuel cells by solid state nuclear magnetic resonance  

SciTech Connect

Solid-state nuclear magnetic resonance (NMR) has been used to explore the nanometer-scale structure of Nafion, the widely used fuel cell membrane, and its composites. We have shown that solid-state NMR can characterize chemical structure and composition, domain size and morphology, internuclear distances, molecular dynamics, etc. The newly-developed water channel model of Nafion has been confirmed, and important characteristic length-scales established. Nafion-based organic and inorganic composites with special properties have also been characterized and their structures elucidated. The morphology of Nafion varies with hydration level, and is reflected in the changes in surface-to-volume (S/V) ratio of the polymer obtained by small-angle X-ray scattering (SAXS). The S/V ratios of different Nafion models have been evaluated numerically. It has been found that only the water channel model gives the measured S/V ratios in the normal hydration range of a working fuel cell, while dispersed water molecules and polymer ribbons account for the structures at low and high hydration levels, respectively.

Kong, Zueqian

2010-03-15T23:59:59.000Z

116

Conformational Exchange in a Membrane Transport Protein Is Altered in Protein Crystals  

SciTech Connect

Successful macromolecular crystallography requires solution conditions that may alter the conformational sampling of a macromolecule. Here, site-directed spin labeling is used to examine a conformational equilibrium within BtuB, the Escherichia coli outer membrane transporter for vitamin B{sub 12}. Electron paramagnetic resonance (EPR) spectra from a spin label placed within the N-terminal energy coupling motif (Ton box) of BtuB indicate that this segment is in equilibrium between folded and unfolded forms. In bilayers, substrate binding shifts this equilibrium toward the unfolded form; however, EPR spectra from this same spin-labeled mutant indicate that this unfolding transition is blocked in protein crystals. Moreover, crystal structures of this spin-labeled mutant are consistent with the EPR result. When the free energy difference between substates is estimated from the EPR spectra, the crystal environment is found to alter this energy by 3 kcal/mol when compared to the bilayer state. Approximately half of this energy change is due to solutes or osmolytes in the crystallization buffer, and the remainder is contributed by the crystal lattice. These data provide a quantitative measure of how a conformational equilibrium in BtuB is modified in the crystal environment, and suggest that more-compact, less-hydrated substates will be favored in protein crystals.

D Freed; P Horanyi; M Wiener; D Cafiso

2011-12-31T23:59:59.000Z

117

Conformational Exchange in a Membrane Transport Protein Is Altered in Protein Crystals  

SciTech Connect

Successful macromolecular crystallography requires solution conditions that may alter the conformational sampling of a macromolecule. Here, site-directed spin labeling is used to examine a conformational equilibrium within BtuB, the Escherichia coli outer membrane transporter for vitamin B{sub 12}. Electron paramagnetic resonance (EPR) spectra from a spin label placed within the N-terminal energy coupling motif (Ton box) of BtuB indicate that this segment is in equilibrium between folded and unfolded forms. In bilayers, substrate binding shifts this equilibrium toward the unfolded form; however, EPR spectra from this same spin-labeled mutant indicate that this unfolding transition is blocked in protein crystals. Moreover, crystal structures of this spin-labeled mutant are consistent with the EPR result. When the free energy difference between substates is estimated from the EPR spectra, the crystal environment is found to alter this energy by 3 kcal/mol when compared to the bilayer state. Approximately half of this energy change is due to solutes or osmolytes in the crystallization buffer, and the remainder is contributed by the crystal lattice. These data provide a quantitative measure of how a conformational equilibrium in BtuB is modified in the crystal environment, and suggest that more-compact, less-hydrated substates will be favored in protein crystals.

Freed, Daniel M.; Horanyi, Peter S.; Wiener, Michael C.; Cafiso, David S. (UV)

2010-09-27T23:59:59.000Z

118

Dynamic characteristics of spherical agglomerate for study of cathode catalyst layers in proton exchange membrane fuel cells (PEMFC)  

Science Journals Connector (OSTI)

There has been growing interest in the modeling of proton exchange membrane fuel cells (PEMFC) over the last two decades. While a variety of steady-state models have been proposed, literature is scarce in PEMFC dynamic models and transient studies. Typical dynamic models for PEM fuel cell are empirical current–voltage relationships. The internal transients associated with reactant and product species and other components are usually neglected. A detailed dynamic model for spherical agglomerate in PEM fuel cell is presented in this work. The dynamic model includes detailed mathematical equations for conservation of oxygen and hydrogen ions inside the agglomerate. The agglomerate dynamic model is simulated for typical operating conditions inside the PEMFC catalyst layer. Simulation studies show that the time scales in which the dynamics of agglomerate potential and concentration of dissolved oxygen respond differ by several orders of magnitude. Transient response of agglomerate current to step changes in surface boundary conditions are also presented. Reasons for the typical characteristics observed in the dynamic behavior of agglomerate current are also highlighted.

R. Madhusudana Rao; R. Rengaswamy

2006-01-01T23:59:59.000Z

119

Oxygen Reduction Kinetics on Electrodeposited PtCo as a Model Catalyst for Proton Exchange Membrane Fuel Cell Cathodes: Stability as a Function of PtCo Composition  

Science Journals Connector (OSTI)

Oxygen Reduction Kinetics on Electrodeposited PtCo as a Model Catalyst for Proton Exchange Membrane Fuel Cell Cathodes: Stability as a Function of PtCo Composition ... When the focus is at reducing cost and improving durability, the PEMFC cathode deserves special attention. ... (4-7) Mukerjee et al. investigated various Pt bimetallic alloys supported on carbon and found a 2?3-fold increase in the oxygen reduction reaction (ORR) activity for the alloy catalysts under PEMFC operating conditions. ...

Kaushik Jayasayee; Van Anh T. Dam; Tiny Verhoeven; Serdar Celebi; Frank A. de Bruijn

2009-11-02T23:59:59.000Z

120

Method of fabricating electrode catalyst layers with directionally oriented carbon support for proton exchange membrane fuel cell  

DOE Patents (OSTI)

A membrane electrode assembly (MEA) of the invention comprises an anode and a cathode and a proton conductive membrane therebetween, the anode and the cathode each comprising a patterned sheet of longitudinally aligned transition metal-containing carbon nanotubes, wherein the carbon nanotubes are in contact with and are aligned generally perpendicular to the membrane, wherein a catalytically active transition metal is incorporated throughout the nanotubes.

Liu, Di-Jia (Naperville, IL); Yang, Junbing (Bolingbrook, IL)

2012-03-20T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
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121

Dopant-Driven Nanostructured Loose-Tube SnO2 Architectures: Alternative Electrocatalyst Supports for Proton Exchange Membrane Fuel Cells  

Science Journals Connector (OSTI)

(6) Recently, SnO2 has also been used as an alternative material to conventional supports for electrocatalysts in proton exchange membrane fuel cells (PEMFC)(7, 8) in an approach attracting increasing interest to remediate the corrosion of conventional carbon support materials. ... Time-effective and reliable methods for studying catalyst durability are indispensable for developing PEMFC catalysts. ... These results indicate that SnO2-supported carbon-free electrocatalysts can be alternatives to the conventional Pt/C electrocatalyst, as a fundamental soln. ...

Sara Cavaliere; Surya Subianto; Iuliia Savych; Monique Tillard; Deborah J. Jones; Jacques Rozière

2013-07-31T23:59:59.000Z

122

Hydrothermal synthesis and formation mechanism of hexagonal yttrium hydroxide fluoride nanobundles  

SciTech Connect

Graphical abstract: The formation of yttrium hydroxide fluorides nanobundles can be expressed as a precipitation transformation from cubic NaYF{sub 4} to hexagonal NaYF{sub 4} and to hexagonal Y(OH){sub 2.02}F{sub 0.98} owing to ion exchange. - Highlights: • Novel Y(OH){sub 2.02}F{sub 0.98} nanobundles have been successfully prepared by hydrothermal method. • The branched nanobundles composed of numerous oriented-attached nanoparticles has been studied. • The growth mechanism is proposed to be ion exchange and precipitation transformation. - Abstract: This article presents the fabrication of hexagonal yttrium hydroxide fluoride nanobundles via one-pot hydrothermal process, using yttrium nitrate, sodium hydroxide and ammonia fluoride as raw materials to react in propanetriol solvent. The X-ray diffraction pattern clearly reveals that the grown product is pure yttrium hydroxide fluoride, namely Y(OH){sub 2.02}F{sub 0.98}. The morphology and microstructure of the synthesized product is testified to be nanobundles composed of numerous oriented-attached nanoparticles as observed from the field emission scanning electron microscopy (FESEM). The chemical composition was analyzed by the energy dispersive spectrum (EDS), confirming the phase transformation of the products which was clearly consistent with the result of XRD analysis. It is proposed that the growth of yttrium hydroxide fluoride nanobundles be attributed to ion exchange and precipitation transformation.

Tian, Li, E-mail: tianli_cl@163.com [Department of Material Science and Engineering, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Sun, QiLiang; Zhao, RuiNi; He, HuiLin; Xue, JianRong [Department of Material Science and Engineering, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Lin, Jun [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

2013-11-15T23:59:59.000Z

123

Platinum-Alloy Cathode Catalyst Degradation in Proton Exchange Membrane Fuel Cells: Nanometer-Scale Compositional and Morphological Changes  

E-Print Network (OSTI)

Electrochemical measurements showed an ?75% Pt surface area loss and an ?40% specific activity loss for a membrane electrode assembly (MEA) cathode with acid-treated “Pt[subscript 3]Co ” catalyst particles in a H[subscript ...

Chen, Shuo

124

Performance analysis of short-side-chain Aquivion® perfluorosulfonic acid polymer for proton exchange membrane water electrolysis  

Science Journals Connector (OSTI)

Abstract An Aquivion® E87-12 S short-side-chain perfluorosulfonic acid (SSC-PFSA) membrane with equivalent weight (EW) of 870 g/eq and 120 ?m thickness produced by Solvay Specialty Polymers was tested in a polymer electrolyte membrane water electrolyzer (PEMWE). For comparison, a benchmark Nafion® N115 membrane (EW 1100 g/eq) of similar thickness was investigated under similar operating conditions. Both membranes were tested in conjunction with in-house prepared unsupported IrO2 anode and carbon-supported Pt cathode electrocatalysts. The electrocatalysts consisted of nanosized IrO2 and Pt particles (particle size ~2–4 nm). Electrochemical tests showed better water splitting performance for the Aquivion® membrane and ionomer based membrane-electrode assembly (MEA) as compared to Nafion®. Lower ohmic drop constraints and smaller polarization resistance were observed for the electrocatalyst–Aquivion® ionomer interface indicating a better catalyst–electrolyte interface. A current density of 3.2 A cm?2 for water electrolysis was recorded at 1.8 V cell voltage and 90 °C with the Aquivion® based MEA. Some performance decay with time was observed indicating that the system requires further optimization of the interface characteristics.

S. Siracusano; V. Baglio; A. Stassi; L. Merlo; E. Moukheiber; A.S. Arico?

2014-01-01T23:59:59.000Z

125

Microwave-assisted synthesis of silica aerogel supported pt nanoparticles for self-humidifying proton exchange membrane fuel cell  

Science Journals Connector (OSTI)

In this study, the mesoporous silica aerogel supported Pt nanoparticle (SAP) was synthesized by the simple microwave-assisted method within 90 s and characterized by WXRD and BET measurements. SAP was then used as a filler to prepare the self-humidifying Nafion®-based composite membrane (N/SAP). The dispersion of the catalyst in N/SAP as well as the water uptake and proton conductivity of N/SAP were investigated. Compared to that of the recast Nafion® membrane (RN), the water uptake and the proton conductivity of N/SAP was improved for about 38% and 109%, respectively. In addition, the power density of the PEMFC single cell fabricated with N/SAP at 50 °C was 1104 mW cm?2 and 913 mW cm?2 measured under the humidified condition and dry condition, respectively, which was approximately 91% and 5.5 times higher than that with RN membrane, respectively.

Cheng-Hsiu Tsai; Feng-Lien Yang; Ching-Hung Chang; Yui Whei Chen-Yang

2012-01-01T23:59:59.000Z

126

Methotrexate intercalated ZnAl-layered double hydroxide  

SciTech Connect

The anticancerous drug methotrexate (MTX) has been intercalated into an ZnAl-layered double hydroxide (LDH) using an anion exchange technique to produce LDH-MTX hybrids having particle sizes in the range of 100-300 nm. X-ray diffraction studies revealed increases in the basal spacings of ZnAl-LDH-MTX hybrid on MTX intercalation. This was corroborated by the transmission electron micrographs, which showed an increase in average interlayer spacing from 8.9 A in pristine LDH to 21.3 A in LDH-MTX hybrid. Thermogravimetric analyses showed an increase in the decomposition temperature for the MTX molecule in the LDH-MTX hybrid indicating enhanced thermal stability of the drug molecule in the LDH nanovehicle. The cumulative release profile of MTX from ZnAl-LDH-MTX hybrids in phosphate buffer saline (PBS) at pH 7.4 was successfully sustained for 48 h following Rigter-Peppas model release kinetics via diffusion. - Graphical abstract: ZnAl-layered double hydroxide intercalated with methotrexate ({approx}34% loading) promises the possibility of use of ZnAl-LDH material as drug carrier and in controlled delivery. Highlights: > ZnAl-layered double hydroxide methotrexate nanohybrid has been synthesized. > XRD and TEM studies on nanohybrid revealed successful intercalation of methotrexate. > TG and CHN analyses showed {approx}34 wt% of methotrexate loading into the nanohybrid. > Possibility of use of ZnAl-LDH material as drug carrier and in delivery.

Chakraborty, Manjusha; Dasgupta, Sudip; Soundrapandian, Chidambaram [Central Glass and Ceramic Research Institute, CSIR, 196 Raja S.C. Mullick Road, Kolkata 700032 (India); Chakraborty, Jui, E-mail: jui@cgcri.res.in [Central Glass and Ceramic Research Institute, CSIR, 196 Raja S.C. Mullick Road, Kolkata 700032 (India); Ghosh, Swapankumar, E-mail: swapankumar.ghosh2@mail.dcu.ie [National Institute for Interdisciplinary Science and Technology (NIIST), CSIR, Trivandrum 695019 (India); Mitra, Manoj K. [Department of Metallurgical and Materials Engineering, Jadavpur University, Kolkata 700032 (India); Basu, Debabrata [Central Glass and Ceramic Research Institute, CSIR, 196 Raja S.C. Mullick Road, Kolkata 700032 (India)

2011-09-15T23:59:59.000Z

127

Program Wednesday, May 15, 2013 UNIVERSITY of DELAWARE  

E-Print Network (OSTI)

.m. Clean Energy: Hydroxide Exchange Membrane Fuel Cells and Flow Batteries Yushan Yan, Professor Chemical

Firestone, Jeremy

128

Nanoscale study of reactive transport in catalyst layer of proton exchange membrane fuel cells with precious and non-precious catalysts using lattice Boltzmann method  

E-Print Network (OSTI)

High-resolution porous structures of catalyst layer (CL) with multicomponent in proton exchange membrane fuel cells are reconstructed using a reconstruction method called quartet structure generation set. Characterization analyses of nanoscale structures are implemented including pore size distribution, specific area and phase connectivity. Pore-scale simulation methods based on the lattice Boltzmann method are developed and used to predict the macroscopic transport properties including effective diffusivity and proton conductivity. Nonuniform distributions of ionomer in CL generates more tortuous pathway for reactant transport and greatly reduces the effective diffusivity. Tortuosity of CL is much higher than conventional Bruggeman equation adopted. Knudsen diffusion plays a significant role in oxygen diffusion and significantly reduces the effective diffusivity. Reactive transport inside the CL is also investigated. Although the reactive surface area of non-precious metal catalyst (NPMC) CL is much higher t...

Chen, Li; Kang, Qinjun; Holby, Edward F; Tao, Wen-Quan

2014-01-01T23:59:59.000Z

129

Method of fabricating electrode catalyst layers with directionally oriented carbon support for proton exchange membrane fuel cell  

DOE Patents (OSTI)

A method of making a membrane electrode assembly (MEA) having an anode and a cathode and a proton conductive membrane there between. A bundle of longitudinally aligned carbon nanotubes with a catalytically active transition metal incorporated in the nanotubes forms at least one portion of the MEA and is in contact with the membrane. A combination selected from one or more of a hydrocarbon and an organometallic compound containing an catalytically active transition metal and a nitrogen containing compound and an inert gas and a reducing gas is introduced into a first reaction zone maintained at a first reaction temperature for a time sufficient to vaporize material therein. The vaporized material is transmitted to a second reaction zone maintained at a second reaction temperature for a time sufficient to grow longitudinally aligned carbon nanotubes with a catalytically active transition metal incorporated throughout the nanotubes. The nanotubes are in contact with a portion of the MEA at production or being positioned in contact thereafter. Methods of forming a PEMFC are also disclosed.

Liu, Di-Jia (Naperville, IL); Yang, Junbing (Willow brook, IL)

2010-07-20T23:59:59.000Z

130

Oblique Soft X-Ray Tomography as a Non-Destructive Method for Morphology Diagnostics in Degradation of Proton-Exchange Membrane Fuel Cell  

Science Journals Connector (OSTI)

Abstract Diagnostics of performance degradation is important for improving the durability of proton-exchange membrane (PEM) fuel cells. X-ray computed tomography (CT) is a valuable non-destructive method to study the internal structure of PEM fuel cells. However, sample cutting is usually needed for high-resolution observations, which prevents the observer from obtaining information about morphology changes during fuel cell testing. In this study, oblique soft X-ray CT has been developed and its suitability as a non-destructive method for PEM fuel cell diagnostics without sample cutting is demonstrated. The CT images of a membrane-electrode assembly (MEA) were obtained at several stages of cell operation, including hot-pressing, load cycles, wet/dry cycles, and start-up/shutdown (SU/SD) experiments. After SU/SD operation, carbon corrosion with newly generated cracks was observed in the catalyst layer at the cathode outlet of the cell, while no corrosion was observed at the cathode inlet and center and at all anode-side positions. The size of cracks in the microporous layer, especially under the rib area, decreased after cell operation. This study validates that it is possible to observe the cause of fuel cell degradation, i.e., carbon corrosion, at a certain position of the MEA under several stages of operation, without cutting the MEA.

Phengxay Deevanhxay; Takashi Sasabe; Katsunori Minami; Shohji Tsushima; Shuichiro Hirai

2014-01-01T23:59:59.000Z

131

Sub-Nanometer-Resolution Elemental Mapping of “Pt3Co” Nanoparticle Catalyst Degradation in Proton-Exchange Membrane Fuel Cells  

Science Journals Connector (OSTI)

However, the specific activity enhancement of “Pt3Co” NPs decreases during PEMFC operation, which has been attributed to the formation of a Pt-enriched shell near the NP surfaces. ... Rate Enhancements in Structural Transformations of Pt–Co and Pt–Ni Bimetallic Cathode Catalysts in Polymer Electrolyte Fuel Cells Studied by in Situ Time-Resolved X-ray Absorption Fine Structure ... In situ time-resolved X-ray absorption fine structure spectra of Pt/C, Pt3Co/C, and Pt3Ni/C cathode electrocatalysts in membrane electrode assemblies (catalyst loading: 0.5 mgmetal cm–2) were successfully measured every 100 ms for a voltage cycling ... ...

Christopher E. Carlton; Shuo Chen; Paulo J. Ferreira; Lawrence F. Allard; Yang Shao-Horn

2011-12-29T23:59:59.000Z

132

Research and development of proton-exchange membrane (PEM) fuel cell system for transportation applications. Phase I final report  

SciTech Connect

Objective during Phase I was to develop a methanol-fueled 10-kW fuel cell power source and evaluate its feasibility for transportation applications. This report documents research on component (fuel cell stack, fuel processor, power source ancillaries and system sensors) development and the 10-kW power source system integration and test. The conceptual design study for a PEM fuel cell powered vehicle was documented in an earlier report (DOE/CH/10435-01) and is summarized herein. Major achievements in the program include development of advanced membrane and thin-film low Pt-loaded electrode assemblies that in reference cell testing with reformate-air reactants yielded performance exceeding the program target (0.7 V at 1000 amps/ft{sup 2}); identification of oxidation catalysts and operating conditions that routinely result in very low CO levels ({le} 10 ppm) in the fuel processor reformate, thus avoiding degradation of the fuel cell stack performance; and successful integrated operation of a 10-kW fuel cell stack on reformate from the fuel processor.

NONE

1996-01-01T23:59:59.000Z

133

Coupling of porous filtration and ion-exchange membranes in an electrodialysis stack and impact on cation selectivity: A novel approach for sea water demineralization and the production of physiological water  

Science Journals Connector (OSTI)

Conventional electrodialysis (ED) and electrodialysis with ultrafiltration (EDUF) or nanofiltration (EDNF) membrane treatments were carried-out for partial desalination of sea water and to evaluate their potential for the production of physiological water. A demineralization rate of 10.6% was obtained with the EDNF and of 40.25% with EDUF and conventional ED processes. The nanofiltration membrane, due to its high electrical resistance, slowed down the migrations of ions. Moreover, the use of an ultrafiltration membrane had no significant effect on the demineralization rate of sea water and the electrodialytic parameters in comparison with the use of conventional ED membranes. A demineralization rate between 20.5 and 30.1% was obtained for each cation analyzed following EDNF treatments and between 43.3 and 64.4% when conventional ED or EDUF was used. Moreover, the decrease in the concentration of monovalent ions was slightly larger than for divalent ions in the case of ED and EDUF while for EDNF, the higher decrease was observed for calcium ion. This means that the replacement of a cation-exchange membrane by an ultrafiltration membrane would not change the selectivity of the process for ion separation but with a nanofiltration membrane a cation-selectivity appears.

Laurent Bazinet; Marianne Moalic

2011-01-01T23:59:59.000Z

134

Sol?Gel Synthesis, Electrochemical Characterization, and Stability Testing of Ti0.7W0.3O2 Nanoparticles for Catalyst Support Applications in Proton-Exchange Membrane Fuel Cells  

Science Journals Connector (OSTI)

Generally, a material with activity for hydrogen evolution can also catalyze hydrogen oxidation; hence, the sample was tested for activity toward hydrogen oxidation. ... The Pt/TiO2 cathode catalyst exhibited excellent fuel cell performance and ultrahigh stability under accelerated stress test conditions and can be considered as a promising alternative for improving the reliability and durability of polymer electrolyte membrane fuel cells. ... Durability of the catalysts in proton exchange membrane fuel cells (PEMFC) is one of the major issues as the oxidn. of carbon catalyst supports causes degrdn. in catalyst performance during cycling in PEMFC. ...

Chinmayee V. Subban; Qin Zhou; Anthony Hu; Thomas E. Moylan; Frederick T. Wagner; Francis J. DiSalvo

2010-11-19T23:59:59.000Z

135

Comparative degradation study of carbon supported proton exchange membrane fuel cell electrocatalysts – The influence of the platinum to carbon ratio on the degradation rate  

Science Journals Connector (OSTI)

Abstract A colloidal synthesis approach is used to prepare supported proton exchange membrane fuel cell (PEMFC) catalysts with various Pt loadings – from low to extremely high ones. The catalyst samples are used to continue our investigation of the role of the Pt:C ratio in the degradation processes. The influence of the platinum loading on the electrochemical surface area (ECSA) loss is evaluated in a systematic electrochemical study by using two commercially available carbon blacks, namely Vulcan XC72R and Ketjenblack EC-300J. Accelerated degradation tests simulating load cycle and start-up/shutdown conditions are carried out in accordance with the Fuel Cell Commercialization Conference of Japan (FCCJ) recommendations. Under conditions simulating the load cycle of PEM fuel cells no unambiguous correlation between the ECSA loss and the Pt:C ratio is found. By contrast, under conditions simulating the repetitive start-up/shutdown processes of \\{PEMFCs\\} the ECSA loss first increases with increasing Pt loading. However, it decreases again for very high loadings. Furthermore, the Vulcan samples exhibited higher ECSA losses than the Ketjenblack samples, indicating the important role of the physical and chemical properties of pristine carbon supports in the carbon degradation mechanism.

Jozsef Speder; Alessandro Zana; Ioannis Spanos; Jacob J.K. Kirkensgaard; Kell Mortensen; Marianne Hanzlik; Matthias Arenz

2014-01-01T23:59:59.000Z

136

Effect of particle size on the activity and durability of the Pt/C electrocatalyst for proton exchange membrane fuel cells  

Science Journals Connector (OSTI)

Carbon supported Pt (Pt/C) with various average particle sizes ranging from sub 3 nm to 6.5 nm were in situ prepared and characterized at the cathode of proton exchange membrane fuel cells (PEMFCs). A clear Pt particle size effect on both the catalytic activity for oxygen reduction reaction (ORR) and the durability of the electrocatalyst was revealed. With the Pt particle size increase, both the surface specific activity and the electrochemical stability of Pt/C improved; however, the mass specific activity of Pt/C is balanced by the electrochemical surface area loss. The reduced occupation of corner and edge atoms on the Pt surface during the Pt particle size increase is believed to weaken the adsorption of the oxygenated species on Pt, and thereafter releases more available active sites for ORR and also renders the Pt surface a stronger resistance against potential cycling. It is therefore proposed that by designing the Pt microstructure with more face atoms on the surface, cathode electrocatalyst with both improved activity and enhanced durability would be developed for PEMFCs.

Zhuang Xu; Huamin Zhang; Hexiang Zhong; Qiuhong Lu; Yunfeng Wang; Dangsheng Su

2012-01-01T23:59:59.000Z

137

Highly Stable and CO-Tolerant Pt/Ti0.7W0.3O2 Electrocatalyst for Proton-Exchange Membrane Fuel Cells  

SciTech Connect

The current materials used in proton-exchange membrane fuel cells (PEMFCs) are not sufficiently durable for commercial deployment. One of the major challenges lies in the development of an inexpensive, efficient, and CO-tolerant anode catalyst. Here we report the unique CO-tolerant property of Pt nanoparticles supported on Ti{sub 0.7}W{sub 0.3}O{sub 2}. The Ti{sub 0.7}W{sub 0.3}O{sub 2} nanoparticles (50 nm) were synthesized via a sol?gel process and platinized using an impregnation?reduction technique. Electrochemical studies of Pt/Ti{sub 0.7}W{sub 0.3}O{sub 2} show unique CO-tolerant electrocatalytic activity for hydrogen oxidation compared to commercial E-TEK PtRu/C catalysts. Differential electrochemical mass spectrometry measurements show the onset potential for CO oxidation on Pt/Ti{sub 0.7}W{sub 0.3}O{sub 2} to be below 0.1 V (vs RHE). Pt/Ti{sub 0.7}W{sub 0.3}O{sub 2} is a promising new anode catalyst for PEMFC applications.

Wang, Deli; Subban, Chinmayee V.; Wang, Hongsen; Rus, Eric; DiSalvo, Francis J.; Abruña, Héctor D.

2010-01-01T23:59:59.000Z

138

Membranes and MEAs for Dry Hot Operating Conditions  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

of this collaborative effort are to develop new proton exchange membranes (PEM's) for fuel cells, integrate them into membrane electrode assemblies (MEA's), and demonstrate in...

139

Membrane module assembly  

DOE Patents (OSTI)

A membrane module assembly is described which is adapted to provide a flow path for the incoming feed stream that forces it into prolonged heat-exchanging contact with a heating or cooling mechanism. Membrane separation processes employing the module assembly are also disclosed. The assembly is particularly useful for gas separation or pervaporation. 2 figures.

Kaschemekat, J.

1994-03-15T23:59:59.000Z

140

Electrodialysis-ion exchange for the separation of dissolved salts. Final report  

SciTech Connect

The program described in this report studies the suitability of electrodialysis-ion exchange (EDIX) to treat aqueous streams containing heavy metals and radioactive cations in a solution containing sodium and nitrates. The goal of the program was to produce a cation stream containing sodium, heavy metals, and radioactive cations; an anion stream of nitric acid free of heavy metals and radioactive cations; and a product stream that meets discharge criteria. The experimental results, described in detail, indicated that EDIX was not a suitable process for treating wastes containing metals that formed insoluble hydroxides in a basic solution; the metals precipitate in the catholyte and feed compartments, and in the cathode membrane. The test program was therefore terminated prior to completion of all planned activities. 2 refs., 22 figs., 8 tabs.

Harrison, J.L.; Baroch, C.J.; Litz, J.

1996-07-19T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Application of layered double hydroxides for removal of oxyanions: A review  

Science Journals Connector (OSTI)

Layered double hydroxides (LDHs) are lamellar mixed hydroxides containing positively charged main layers and undergoing anion exchange chemistry. In recent years, many studies have been devoted to investigating the ability of \\{LDHs\\} to remove harmful oxyanions such as arsenate, chromate, phosphate, etc. from contaminated waters by both surface adsorption and anion exchange of the oxyanions for interlayer anions in the LDH structure. This review article provides an overview of the LDH synthesis methods, the LDH characterization techniques, and the recent advancement that has been achieved in oxyanion removal using LDHs, highlighting areas of consensus and currently unresolved issues. Experimental studies relating to the sorption behaviors of \\{LDHs\\} with various oxyanions, and the kinetic models adopted to explain the adsorption rate of oxyanions from aqueous solution onto LDHs, have been comprehensively reviewed. This review discusses several key factors such as pH, competitive anions, temperature, etc., that influence the oxyanion adsorption on LDHs. The reusability of \\{LDHs\\} is discussed and some mechanistic studies of oxyanion adsorption on \\{LDHs\\} are highlighted. The sorption capacities of \\{LDHs\\} for various oxyanions are also compared with those of other adsorbents. In addition, this review critically identifies the shortcomings in current research on LDHs, such as the common weaknesses in the adopted methodology, discrepancies among reported results and ambiguous conclusions. Possible improvement of \\{LDHs\\} and potential areas for future application of \\{LDHs\\} are also proposed.

Kok-Hui Goh; Teik-Thye Lim; Zhili Dong

2008-01-01T23:59:59.000Z

142

Product development of FGD recovered magnesium hydroxide  

SciTech Connect

The ThioClear FGD processes developed by the Dravo Lime Company (DLC) produce a high brightness gypsum and magnesium hydroxide (Mg(OH){sub 2}) by-product. Both originate as white precipitates from a solution of magnesium sulfate. The use of magnesium-enhanced lime avoids the mineral impurities from direct neutralization when using pulverized limestone rock. White, pure FGD synthetic gypsum can be used to produce higher value products such as mineral fillers and industrial plasters. This paper focuses on the product development of the Mg(OH){sub 2} by-product. Commercial Mg(OH){sub 2} sells at over $200/Ton for a variety of uses, most of which is wastewater treatment and a feedstock to make magnesium chemicals and refractories. Beneficial uses in the power plant are pH control of acidic coal pile stormwater runoff and bottom ash quench water. A future use being explored is injection into coal fired boilers to neutralize sulfur trioxide (SO{sub 3}) to prevent stack gas opacity related emission problems and minimize air preheater corrosion and fouling. The objective of this project is to improve the purity and solids content of the by-product after it is separated from the gypsum. Several options were investigated to convert it into a more marketable or usable form. Test results and economic evaluations are reported during the different process steps needed to improve the product quality: (1) dissolving or washing out the gypsum impurity; (2) thickening the washed solids and using the overflow for makeup water within the FGD water balance; (3) finding the best means to dewater the washed, thickened slurry; and (4) repulp the dewatered cake into a stabilized slurry or dry it to powder. Flash drying the dewatered cake is compared to spray drying the thickened slurry. FGD Mg(OH){sub 2} is shown to have equal reactivity as an acid neutralization reagent on a Mg(OH){sub 2} molar basis to commercial Mg(OH){sub 2} products and other alkaline reagents. Its use for pH control in wastewater treatment is shown to produce a much smaller sludge volume than lime or sodium hydroxide.

Beeghly, J.H.; Babu, M.; Smith, K.J.

1999-07-01T23:59:59.000Z

143

Sodium Hydroxide Extraction From Caustic Leaching Solutions  

SciTech Connect

This report describes experiments conducted to demonstrate the proof-of-principle of a method to recover NaOH from Hanford tank sludge leaching solutions. Aqueous solutions generated from leaching actual Hanford tank waste solids were used. The process involves neutralization of a lipophilic weak acid (t-octylphenol was used in these experiments) by reaction with NaOH in the aqueous phase. This results in the transfer of Na into the organic phase. Contacting with water reverses this process, reprotonating the lipophilic weak acid and transferring Na back into the aqueous phase as NaOH. The work described here confirms the potential application of solvent extraction to recover and recycle NaOH from solutions generated by leaching Hanford tank sludges. Solutions obtained by leaching sludges from tanks S-110 and T-110 were used in this work. It was demonstrated that Na+ is transferred from caustic leaching solution to the organic phase when contacted with t-octylphenol solutions. This was accompanied by a concomitant decrease in the aqueous-phase hydroxide ion concentration. Seventy to 80 % of the extracted Na was recovered by 3 to 4 sequential contacts of the organic phase with water. Cesium was co-extracted by the procedure, but Al and Cr remained in the feed stream.

Lumetta, Gregg J.; Garza, Priscilla A.; Levitskaia, Tatiana G.; Brown, Gilbert M.

2002-09-18T23:59:59.000Z

144

Hysteresis During Cycling of Nickel Hydroxide Active Material  

NLE Websites -- All DOE Office Websites (Extended Search)

Hysteresis During Cycling of Nickel Hydroxide Active Material Hysteresis During Cycling of Nickel Hydroxide Active Material Title Hysteresis During Cycling of Nickel Hydroxide Active Material Publication Type Journal Article Year of Publication 2001 Authors Srinivasan, Venkat, John W. Weidner, and John S. Newman Journal Electrochemical Society Volume 148 Start Page A969 Issue 9 Pagination A969-A980 Date Published 04/2001 Abstract The nickel hydroxide electrode is known to exhibit a stable hysteresis loop, with the potential on charge being higher than that on discharge at every state-of-charge ~SOC!.What we show here is that this loop created during a complete charge and discharge ~i.e., boundary curves! is not sufficient to define the state of the system. Rather, internal paths within the boundary curves ~i.e., scanning

145

Surface-Induced Nickel Hydroxide Precipitation in the Presence of Citrate and Salicylate  

E-Print Network (OSTI)

). These identified the Ni hydroxide precipitates with diffuse reflectance spec- LDH phases consist of brucite

Sparks, Donald L.

146

Effects of Tungsten Oxide Addition on the Electrochemical Performance of Nanoscale Tantalum Oxide-Based Electrocatalysts for Proton Exchange Membrane PEM Fuel Cells  

SciTech Connect

In the present study, the properties of a series of non-platinum based nanoscale tantalum oxide/tungsten oxide-carbon composite catalysts was investigated for potential use in catalyzing the oxygen reduction reaction (ORR) on the cathode side of a PEM fuel cell membrane electrode assembly. Electrochemical performance was measured using a half-cell test set up with a rotating disc electrode and compared with a commercial platinum-on-carbon (Pt/C) catalyst. Overall, all of the oxide-based composite catalysts exhibit high ORR on-set potentials, comparable to that of the baseline Pt/C catalyst. The addition of tungsten oxide as a dopant to tantalum oxide greatly improved mass specific current density. Maximum performance was achieved with a catalyst containing 32 mol% of tungsten oxide, which exhibited a mass specific current density ~8% that of the Pt/C catalyst at 0.6 V vs. the normal hydrogen electrode (NHE) and ~35% that of the Pt/C catalyst at 0.2 V vs. NHE. Results from X-ray photoelectron spectroscopy analysis indicated that the tungsten cations in the composite catalysts exist in the +6 oxidation state, while the tantalum displays an average valence of +5, suggesting that the addition of tungsten likely creates an oxygen excess in the tantalum oxide structure that influences its oxygen absorption kinetics. When the 32mol% tungsten doped catalyst loading on the working electrode was increased to five times that of the original loading (which was equivalent to that of the baseline Pt/C catalyst), the area specific current density improved four fold, achieving an area specific current density ~35% that of the Pt/C catalyst at 0.6 V vs. NHE.

Oh, Tak Keun; Kim, Jin Yong; Shin, Yongsoon; Engelhard, Mark H.; Weil, K. Scott

2011-08-01T23:59:59.000Z

147

Design and Development of New Glass-Ceramic Proton Conducting Membranes  

E-Print Network (OSTI)

oxide anion conductivity. These membranes being solid in nature do not suffer from fuel cross membranes, phosphoric acid membranes, and solid oxide membranes. Polymer exchange membranes, or more electrodes. Solid oxide membranes are typically operated between 700o C to 1,000o C, where the use

148

Frequency control of a new topology in proton exchange membrane fuel cell/wind turbine/photovoltaic/ultra-capacitor/battery energy storage system based isolated networks by a novel intelligent controller  

Science Journals Connector (OSTI)

This paper proposes a new topology for hybrid isolated networks employing a wind turbine (WT) proton exchange membrane fuel cell (PEMFC) photovoltaic ultra-capacitor (UC) and battery energy storage system (BESS). The PEMFC is used in parallel with the UC and BESS; a configuration that improves the performance of the PEMFC in terms of dynamic response and lifetime. The proposed topology of the PEMFC along with a new model of WT reduces the initial costs of the hybrid isolated network. Due to power demand fluctuations in isolated networks to maintain the balance between power generation and consumption intelligent and flexible control methods must be applied. The variations of the solar irradiance of the wind speed and of the power consumption in hybrid isolated networks render the classic controllers and even fuzzy controllers inefficient. To overcome this problem we use a novel intelligent fuzzy controller which is optimized by the teaching-learning-based optimization method. In the structure of the new proposed controller the range and place of membership functions are optimized to reduce network frequency oscillations and improve network frequency stability. The designed control methodology is evaluated in the proposed isolated network and its performance is compared with the fuzzy controller proportional integral (PI) controller and optimal PI controller. To demonstrate the effectiveness of the proposed control strategies the above-mentioned detailed mathematical and dynamic models of the isolated network were integrated using MATLAB/Simulink.

2014-01-01T23:59:59.000Z

149

Ion Conducting Membranes for Fuel Cells and other Electrochemical Devices  

Science Journals Connector (OSTI)

ion conducting membrane; fuel cell; redox-flow battery; Li ion battery; proton; hydroxide; diffusion; conductivity; nanomorphology; hydration; visco-elastic constants; phosphate; polyelectrolyte; ionomer; block-copolymer; Nafion; Aquivion ... At this stage, however, they have an immediate potential for redox-flow battery applications, as will be discussed later. ... When the flow battery is charged or discharged, an equivalent amount of ionic charge has to cross the membrane, while the ions involved in the redox process have to be efficiently separated. ...

Klaus-Dieter Kreuer

2013-11-19T23:59:59.000Z

150

Composite oxygen transport membrane  

DOE Patents (OSTI)

A method of producing a composite oxygen ion membrane and a composite oxygen ion membrane in which a porous fuel oxidation layer and a dense separation layer and optionally, a porous surface exchange layer are formed on a porous support from mixtures of (Ln.sub.1-xA.sub.x).sub.wCr.sub.1-yB.sub.yO.sub.3-.delta. and a doped zirconia. In the porous fuel oxidation layer and the optional porous surface exchange layer, A is Calcium and in the dense separation layer A is not Calcium and, preferably is Strontium. Preferred materials are (La.sub.0.8Ca.sub.0.2).sub.0.95Cr.sub.0.5Mn.sub.0.5O.sub.3-.delta. for the porous fuel oxidation and optional porous surface exchange layers and (La.sub.0.8Sr.sub.0.2).sub.0.95Cr.sub.0.5Fe.sub.0.5O.sub.3-.delta. for the dense separation layer. The use of such materials allows the membrane to sintered in air and without the use of pore formers to reduce membrane manufacturing costs. The use of materials, as described herein, for forming the porous layers have application for forming any type of porous structure, such as a catalyst support.

Christie, Gervase Maxwell; Lane, Jonathan A.

2014-08-05T23:59:59.000Z

151

General Insights into Structural Evolution of Layered Double Hydroxide: Underlying Aspects in Topochemical Transformation from Brucite to Layered Double Hydroxide  

Science Journals Connector (OSTI)

General Insights into Structural Evolution of Layered Double Hydroxide: Underlying Aspects in Topochemical Transformation from Brucite to Layered Double Hydroxide ... The topochemical transformation from transition-metal brucite hydroxide (Co1-xFex(OH)2, Co(OH)2, Co1-xNix(OH)2) to corresponding (Co2+–(Co3+)–Fe3+, Co2+–(Ni2+)–Co3+) LDH under oxidizing halogen agents (iodine, bromine) exhibits different staging phenomena depending on the metallic composition/ratio in starting brucite. ... A plausible charge hopping mechanism based on valence interchange between redoxable charge center (Fe3+/Co3+) and neighboring divalent sites in the host sheet is proposed to understand the restoration of electron donor sites at the interface between brucite crystallites and halogen agents, which ensures a continual oxidative reaction, and a staged intercalation/diffusion of in situ reduced halide anions into the interlayer gallery commensurate with the host charge propagation. ...

Renzhi Ma; Jianbo Liang; Xiaohe Liu; Takayoshi Sasaki

2012-11-08T23:59:59.000Z

152

Solid-State NMR Spectroscopic Study of Phosphate Sorption Mechanisms on Aluminum (Hydr)oxides  

E-Print Network (OSTI)

Solid-State NMR Spectroscopic Study of Phosphate Sorption Mechanisms on Aluminum (Hydr)oxides Wei the mechanism of phosphate sorption on aluminum hydroxides under different environ- mental conditions, including

Sparks, Donald L.

153

DOUBLE SHELL TANK (DST) HYDROXIDE DEPLETION MODEL FOR CARBON DIOXIDE ABSORPTION  

SciTech Connect

This document generates a supernatant hydroxide ion depletion model based on mechanistic principles. The carbon dioxide absorption mechanistic model is developed in this report. The report also benchmarks the model against historical tank supernatant hydroxide data and vapor space carbon dioxide data. A comparison of the newly generated mechanistic model with previously applied empirical hydroxide depletion equations is also performed.

OGDEN DM; KIRCH NW

2007-10-31T23:59:59.000Z

154

Anion Exchange Membranes for Fuel Cells  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Parallel Breakout Sessions) * Stability Challenges - Chemical (OH attack) - Other (Mechanical, RH, peroxide?) * TransportConductivity Challenges - Conductivity - Water Uptake -...

155

The reaction of cesium hydroxide with 4-phenylvaleric acid  

E-Print Network (OSTI)

Alkali Metal Hycroxide Solutions Used in Potentio- metric and Spectrophotometric Titrations with 4-Phenylvaleric Acid 17 Samples for Nuclear Magnetic Resonance Spectra 18 Concentration of 4-Phenylvaleric Acid in Carbon Tetrachloride for Infrared.... Similarly, nuclear magnetic resonance techniques may be used to determine whether any TT-bonding involving the phenyl ring of 4- phenylvaleric acid occurs during its reaction with cesium hydroxide. If any such bonding to the n-electrons of the ring occurs...

Caughfield, Arvie Jeane

2012-06-07T23:59:59.000Z

156

THE VITELLINE MEMBRANE OF THE UNFERTILIZED HEN'S EGG  

E-Print Network (OSTI)

membrane is charged and asymmetrical. It's directional specificity to ion transport and accompanying volumeTHE VITELLINE MEMBRANE OF THE UNFERTILIZED HEN'S EGG : ELECTROLYTE AND WATER TRANSPORT T. RYMEN J more than just the result of the membrane's ion exchange behaviour and that it may involve an enzymatic

Paris-Sud XI, Université de

157

Membrane processes relevant for the polymer electrolyte fuel cell  

E-Print Network (OSTI)

Membrane processes relevant for the polymer electrolyte fuel cell Aleksander Kolstad Chemical. The important aspects concerning the Polymer Electrolyte Membrane Fuel Cell, more commonly known as Proton Exchange Membrane Fuel Cell (PEMFC), have been studied in two separate parts. Part 1 of the thesis

Kjelstrup, Signe

158

Method of treating inflammatory diseases using a radiolabeled ferric hydroxide calloid  

DOE Patents (OSTI)

A ferric hydroxide colloid having an alpha-emitting radionuclide essentially on the outer surfaces and a method of forming same. The method includes oxidizing a ferrous hydroxide to ferric hydroxide in the presence of a preselected radionuclide to form a colloid having the radionuclide on the outer surface thereof, and thereafter washing the colloid, and suspending the washed colloid in a suitable solution. The labelled colloid is useful in cancer therapy and for the treatment of inflamed joints.

Atcher, Robert W. (Chicago, IL); Hines, John J. (Glen Ellyn, IL)

1992-01-01T23:59:59.000Z

159

Layered double hydroxides : synthesis and application in gene delivery to mammalian cells in culture.  

E-Print Network (OSTI)

??Layered double hydroxides (LDHs) or hydrotalcite-like compounds (HTLcs) are classified as anionic clays in which their structure is based upon brucite and are represented by… (more)

Balcomb, Blake.

2010-01-01T23:59:59.000Z

160

E-Print Network 3.0 - aluminium hydroxides Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

on the powder by heating... process was to convert the oxides or hydroxides to carbides and nitrides by carburizing them with methane Source: Ecole Polytechnique, Centre de...

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Synthetic hydrotalcite-type and hydrocalumite-type layered double hydroxides for arsenate uptake  

Science Journals Connector (OSTI)

The objectives of this study were to (i) synthesize cost-effective layered double hydroxides (LDH) or anionic clays to remove arsenate from water and (ii) quantify arsenate uptake by LDH and understand the mechanisms of uptake. Hydrotalcite and hydrocalumite-type \\{LDHs\\} were synthesized by coprecipitation at room temperature or higher with different compositions of layers and interlayers. The kinetics study showed that anion exchange apparently attained a steady-state in the range of 8–16 h. The arsenate removal was 100% and 99.9% with nitrate form of hydrotalcite and hydrocalumite, respectively. Carbonate and chloride forms of hydrotalcite and chloride form of hydrocalumite removed 50–90% of arsenate from solution. The uptake capacities of hydrotalcites synthesized by different methods were also compared. Hydrotalcite-type LDH synthesized by coprecipitation method had greater uptake capacity than those synthesized by hydrothermal method because of smaller crystal size in the former. The uptake of oxyanions with calcined hydrotalcite-type LDH was higher than with commercially available uncalcined carbonate form of hydrotalcite-type LDH, as expected. Calcination of hydrotalcite-type LDH produced intermediate non-stoichiometric oxides, which underwent rehydration and regeneration of the structure with the incorporation of these oxyanions. In the presence of much larger concentrations of other anions, the uptake of arsenate was reduced but it was still selective on LDH. The results of uptake were confirmed by powder X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM).

Kanchan Grover; Sridhar Komarneni; Hiroaki Katsuki

2010-01-01T23:59:59.000Z

162

Study of two sampling procedures for the valorization of metal hydroxide sludge as pollutant trapper  

E-Print Network (OSTI)

treatment, CrVI 1 Introduction Industrial aqueous pollution (heavy metals) accounts for 30 to 40% of all1 Study of two sampling procedures for the valorization of metal hydroxide sludge as pollutant@emse.fr Abstract: For the valorisation of metal hydroxide sludge as adsorbent of pollutant, it is necessary to make

Boyer, Edmond

163

Alternate Fuel Cell Membranes for Energy Independence  

SciTech Connect

The overall objective of this project was the development and evaluation of novel hydrocarbon fuel cell (FC) membranes that possess high temperature performance and long term chemical/mechanical durability in proton exchange membrane (PEM) fuel cells (FC). The major research theme was synthesis of aromatic hydrocarbon polymers of the poly(arylene ether sulfone) (PAES) type containing sulfonic acid groups tethered to the backbone via perfluorinated alkylene linkages and in some cases also directly attached to the phenylene groups along the backbone. Other research themes were the use of nitrogen-based heterocyclics instead of acid groups for proton conduction, which provides high temperature, low relative humidity membranes with high mechanical/thermal/chemical stability and pendant moieties that exhibit high proton conductivities in the absence of water, and synthesis of block copolymers consisting of a proton conducting block coupled to poly(perfluorinated propylene oxide) (PFPO) blocks. Accomplishments of the project were as follows: 1) establishment of a vertically integrated program of synthesis, characterization, and evaluation of FC membranes, 2) establishment of benchmark membrane performance data based on Nafion for comparison to experimental membrane performance, 3) development of a new perfluoroalkyl sulfonate monomer, N,N-diisopropylethylammonium 2,2-bis(p-hydroxyphenyl) pentafluoropropanesulfonate (HPPS), 4) synthesis of random and block copolymer membranes from HPPS, 5) synthesis of block copolymer membranes containing high-acid-concentration hydrophilic blocks consisting of HPPS and 3,3'-disulfonate-4,4'-dichlorodiphenylsulfone (sDCDPS), 6) development of synthetic routes to aromatic polymer backbones containing pendent 1H-1,2,3-triazole moieties, 7) development of coupling strategies to create phase-separated block copolymers between hydrophilic sulfonated prepolymers and commodity polymers such as PFPO, 8) establishment of basic performance properties of experimental membranes, 9) fabrication and FC performance testing of membrane electrode assemblies (MEA) from experimental membranes, and 10) measurement of ex situ and in situ membrane durability of experimental membranes. Although none of the experimental hydrocarbon membranes that issued from the project displayed proton conductivities that met DOE requirements, the project contributed to our basic understanding of membrane structure-property relationships in a number of key respects. An important finding of the benchmark studies is that physical degradation associated with humidity and temperature variations in the FC tend to open new fuel crossover pathways and act synergistically with chemical degradation to accelerate overall membrane degradation. Thus, for long term membrane survival and efficient fuel utilization, membranes must withstand internal stresses due to humidity and temperature changes. In this respect, rigid aromatic hydrocarbon fuel cell membranes, e.g. PAES, offer an advantage over un-modified Nafion membranes. The benchmark studies also showed that broadband dielectric spectroscopy is a potentially powerful tool in assessing shifts in the fundamental macromolecular dynamics caused by Nafion chemical degradation, and thus, this technique is of relevance in interrogating proton exchange membrane durability in fuel cells and macromolecular dynamics as coupled to proton migration, which is of fundamental relevance in proton exchange membranes in fuel cells. A key finding from the hydrocarbon membrane synthesis effort was that rigid aromatic polymers containing isolated ion exchange groups tethered tightly to the backbone (short tether), such as HPPS, provide excellent mechanical and durability properties but do not provide sufficient conductivity, in either random or block configuration, when used as the sole ion exchange monomer. However, we continue to hypothesize that longer tethers, and tethered groups spaced more closely within the hydrophilic chain elements of the polymer, will yield highly conductive materials with excellent mech

Storey, Robson, F.; Mauritz, Kenneth, A.; Patton, Derek, L.; Savin, Daniel, A.

2012-12-18T23:59:59.000Z

164

Heat exchanger  

DOE Patents (OSTI)

A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

Brackenbury, Phillip J. (Richland, WA)

1986-01-01T23:59:59.000Z

165

Heat exchanger  

DOE Patents (OSTI)

A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

Brackenbury, P.J.

1983-12-08T23:59:59.000Z

166

Development of an spFRET method to measure structure changes in ion exchange proteins  

E-Print Network (OSTI)

transporter, major facilitator superfamily, membrane transport, membrane transporter, OxlT, single molecule, spFRET, transport protein. Tightly coupled ion exchangers, such as the AE anion exchange systems only take place at an appreciable rate if a suitable substrate ion is bound to the transport site

Novotny, Lukas

167

Honeywell Modular Automation System Computer Software Documentation for the Magnesium Hydroxide Precipitation Process  

SciTech Connect

The purpose of this Computer Software Document (CSWD) is to provide configuration control of the Honeywell Modular Automation System (MAS) in use at the Plutonium Finishing Plant (PFP) for the Magnesium Hydroxide Precipitation Process in Rm 230C/234-5Z. The magnesium hydroxide process control software Rev 0 is being updated to include control programming for a second hot plate. The process control programming was performed by the system administrator. Software testing for the additional hot plate was performed per PFP Job Control Work Package 2Z-00-1703. The software testing was verified by Quality Control to comply with OSD-Z-184-00044, Magnesium Hydroxide Precipitation Process.

STUBBS, A.M.

2001-06-25T23:59:59.000Z

168

Segmented heat exchanger  

DOE Patents (OSTI)

A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

Baldwin, Darryl Dean (Lafayette, IN); Willi, Martin Leo (Dunlap, IL); Fiveland, Scott Byron (Metamara, IL); Timmons, Kristine Ann (Chillicothe, IL)

2010-12-14T23:59:59.000Z

169

Interferometric tomography of fuel cells for monitoring membrane water content  

E-Print Network (OSTI)

We have developed a system that uses two 1D interferometric phase projections for reconstruction of 2D water content changes over time in situ in a proton exchange membrane (PEM) fuel cell system. By modifying the filtered ...

Waller, Laura

170

A comparison of ROChem reverse osmosis and spiral wound reverse osmosis membrane modules  

SciTech Connect

Testing of the ROChem Disc Tube[reg sign] reverse osmosis (RO) module's performance on biologically active feed waters has been completed. Both the ROChem module (using Filmtec standard-rejection seawater membranes) and the Filmtec spiral-wound membrane module (using Filmtec high-rejection seawater membranes) were tested with stimulant solutions containing typical bacteria and metal hydroxide levels found in the F/H Effluent Treatment Facility (ETF) influent. Results indicate that the ROChem module gave superior performance over the spiral-wound module. Water flux losses were reduced by over 30% for water recoveries above 40%.

Siler, J.L.

1992-01-31T23:59:59.000Z

171

A comparison of ROChem reverse osmosis and spiral wound reverse osmosis membrane modules  

SciTech Connect

Testing of the ROChem Disc Tube{reg_sign} reverse osmosis (RO) module`s performance on biologically active feed waters has been completed. Both the ROChem module (using Filmtec standard-rejection seawater membranes) and the Filmtec spiral-wound membrane module (using Filmtec high-rejection seawater membranes) were tested with stimulant solutions containing typical bacteria and metal hydroxide levels found in the F/H Effluent Treatment Facility (ETF) influent. Results indicate that the ROChem module gave superior performance over the spiral-wound module. Water flux losses were reduced by over 30% for water recoveries above 40%.

Siler, J.L.

1992-01-31T23:59:59.000Z

172

Membrane magic  

SciTech Connect

The Kansas Power and Light Co.'s La Cyne generating station has found success with membrane filtration water pretreatment technology. The article recounts the process followed in late 2004 to install a Pall Aria 4 microfilter in Unit 1 makeup water system at the plant to produce cleaner water for reverse osmosis feed. 2 figs., 2 photos.

Buecker, B. [Kansas City Power and Light Co. (United States)

2005-09-01T23:59:59.000Z

173

A Ni-Fe Layered Double Hydroxide-Carbon Nanotube Complex for Water Oxidation  

E-Print Network (OSTI)

Highly active, durable and cost-effective electrocatalysts for water oxidation to evolve oxygen gas hold a key to a range of renewable energy solutions including water splitting and rechargeable metal-air batteries. Here, we report the synthesis of ultrathin nickel iron layered double hydroxide nanoplates on mildly oxidized multi-walled carbon nanotubes. Incorporation of Fe into the nickel hydroxide induced the formation of NiFe-layered double hydroxide. The nanoplates were covalently attached to a network of nanotubes, affording excellent electrical wiring to the nanoplates. The ultra-thin Ni-Fe layered double hydroxide nanoplates/carbon nanotube complex was found to exhibit unusually high electro-catalytic activity and stability for oxygen evolution and outperformed commercial precious metal Ir catalysts.

Gong, Ming; Wang, Hailiang; Liang, Yongye; Wu, Justin Zachary; Zhou, Jigang; Wang, Jian; Regier, Tom; Wei, Fei; Dai, Hongjie

2013-01-01T23:59:59.000Z

174

Structure of aluminum hydroxide powders obtained as a byproduct of hydrogen fuel production  

Science Journals Connector (OSTI)

The structure of aluminum hydroxide powders obtained as byproducts of hydrogen fuel production was investigated. One of the main initial components comprised aluminum-magnesium chips with 0.6, 6 and 12 wt.% ma...

A. D. Shlyapin; A. Yu. Omarov; V. P. Tarasovskii; Yu. G. Trifonov

2013-09-01T23:59:59.000Z

175

Analysis of Hydroxide Sorbents for CO2 Capture from Warm Syngas  

Science Journals Connector (OSTI)

Analysis of Hydroxide Sorbents for CO2 Capture from Warm Syngas ... (1, 2) However, conventional coal combustion releases large amounts of the greenhouse gas CO2 into the atmosphere. ...

David J. Couling; Ujjal Das; William H. Green

2012-09-04T23:59:59.000Z

176

Reduction of Tc(VII) by Fe(II) Sorbed on Al (hydr)oxides. | EMSL  

NLE Websites -- All DOE Office Websites (Extended Search)

by Fe(II) Sorbed on Al (hydr)oxides. Abstract: Technetium speciation, solubility and sorption behavior is strongly dependent on its valence state. Under oxic conditions, Tc exists...

177

Nested potassium hydroxide etching and protective coatings for silicon-based microreactors  

E-Print Network (OSTI)

We have developed a multilayer, multichannel silicon-based microreactor that uses elemental fluorine as a reagent and generates hydrogen fluoride as a byproduct. Nested potassium hydroxide etching (using silicon nitride ...

de Mas, Nuria

178

New possibilities of electroinduced membrane gas and vapor separation  

SciTech Connect

A novel membrane technique to effect electroinduced facilitated transport of neutral molecules in ion-exchange membranes was suggested. Experiments have been carried out with platinum-coated Nafion membranes in Cu{sup 2+}/Cu{sup 1+} form. This may be a potential technique for the separation of olefin/paraffin mixtures. It was shown that by applying an electric current to the membrane the permeability of ethylene increased 6-fold, compared to the permeability of the initial Pt-coated membrane without current.

Bessarabov, D.G.; Sanderson, R.D. [Univ. of Stellenbosch (South Africa). Inst. for Polymer Science] [Univ. of Stellenbosch (South Africa). Inst. for Polymer Science; Valuev, V.V.; Popkov, Y.M.; Timashev, S.F. [Karpov Inst. of Physical Chemistry, Moscow (Russian Federation)] [Karpov Inst. of Physical Chemistry, Moscow (Russian Federation)

1997-06-01T23:59:59.000Z

179

Aptamer Directly Evolved from Live Cells Recognizes Membrane Bound Immunoglobin  

E-Print Network (OSTI)

. These include cell signaling, cell-cell interactions, ion/solute transport that facilitates the exchangeAptamer Directly Evolved from Live Cells Recognizes Membrane Bound Immunoglobin Heavy Mu Chain, and Weihong Tan The identification of tumor related cell membrane protein targets is important

Tan, Weihong

180

Psychology on Exchange InternationalExchangeProgram  

E-Print Network (OSTI)

Psychology on Exchange InternationalExchangeProgram Psychology majors are welcome to apply Honours, you need to take into account the advice from the Department of Psychology (http://sydney.edu.au/ current_students/student_exchange/forms_downloads.shtml). Timing To meet Australian Psychology

Viglas, Anastasios

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Microsoft Word - 25A5311 Continued  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

By switching fuel cell electrochemical reactions from an acidic medium to a basic one and utilizing highly conductive hydroxide exchange By switching fuel cell electrochemical reactions from an acidic medium to a basic one and utilizing highly conductive hydroxide exchange membranes, the high-performance hydroxide exchange membrane fuel cells (HEMFCs) are a truly innovative technology and radically different from the proton exchange membrane fuel cells (PEMFCs) that have been intensively researched and developed in the past two decades. The most exciting ability of HEMFCs is to solve fundamentally the PEMFCs' serious problems of catalysts cost and durability, while achieving PEMFCs' high power and energy density simultaneously. What has been critically missing for HEMFCs is a polymeric hydroxide exchange membrane (HEM) with high hydroxide conductivity and stability. With the totally revolutionarily design of hydroxide conducting functional

182

Microsoft Word - 25A5311 Continued  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

By switching fuel cell electrochemical reactions from an acidic medium to a basic one and utilizing highly conductive hydroxide exchange By switching fuel cell electrochemical reactions from an acidic medium to a basic one and utilizing highly conductive hydroxide exchange membranes, the high-performance hydroxide exchange membrane fuel cells (HEMFCs) are a truly innovative technology and radically different from the proton exchange membrane fuel cells (PEMFCs) that have been intensively researched and developed in the past two decades. The most exciting ability of HEMFCs is to solve fundamentally the PEMFCs' serious problems of catalysts cost and durability, while achieving PEMFCs' high power and energy density simultaneously. What has been critically missing for HEMFCs is a polymeric hydroxide exchange membrane (HEM) with high hydroxide conductivity and stability. With the totally revolutionarily design of hydroxide conducting functional

183

Sulfonated Polysulfone/POSS Nanofiber Composite Membranes for PEM Fuel Cells  

E-Print Network (OSTI)

Sulfonated Polysulfone/POSS Nanofiber Composite Membranes for PEM Fuel Cells Jonghyun Choi. Historically, most of the research work on Nafion replacements for proton exchange membrane PEM fuel cells has in H2/air fuel cells that operate at low humidity. The membranes were fabricated from electrospun

Mather, Patrick T.

184

Selective Aerobic Oxidation of 5-Hydroxymethylfurfural in Water Over Solid Ruthenium Hydroxide Catalysts with Magnesium-Based Supports  

Science Journals Connector (OSTI)

Solid catalyst systems comprised of ruthenium hydroxide supported on magnesium-based carrier materials (spinel, magnesium oxide and hydrotalcite) were investigated for the selective, aqueous aerobic oxidation of ...

Yury Y. Gorbanev; Søren Kegnæs; Anders Riisager

2011-12-01T23:59:59.000Z

185

Sorption of oxyanions on nanocrystalline Mg/Al layered double hydroxides : sorption characteristics, mechanisms, and matrix interferences.  

E-Print Network (OSTI)

??Nanocrystalline Mg/Al layered double hydroxide (LDH) with nitrate intercalation produced in this study exhibited excellent affinity for polyvalent oxyanions, but comparatively less affinity for monovalent… (more)

Goh, Kok Hui.

2010-01-01T23:59:59.000Z

186

Formation and Stability of Ni-Al Hydroxide Phases in Soils  

SciTech Connect

The formation of mixed metal-aluminum hydroxide surface precipitates is a potentially significant uptake route for trace metals (including Co, Ni, and Zn) in environmental systems. This paper investigates the effect of mixed Ni-Al hydroxide precipitate formation and aging on Ni solubility and bioavailability in laboratory contaminated soils. Two Delaware agricultural soils were reacted with a 3 mM Ni solution for 12 months at pH's above and below the threshold for mixed Ni-Al hydroxide formation. Ni speciation was determined at 1, 6, and 12 months using X-ray absorption spectroscopy (XAS). Precipitate solubility was examined through desorption experiments using HNO{sub 3} and EDTA as desorbing agents, whereas metal bioavailability was assessed using a Ni-specific bacterial biosensor. For both soils, the formation of Ni-Al hydroxide surface precipitates resulted in a reduction in the fraction of desorbed and bioavailable Ni. However, precipitate dissolution was greater, particularly with EDTA, than in published studies on isolated soil clay fractions, and less affected by aging processes. These results suggest that mixed Ni-Al hydroxide phases forming in real world environments may be both longer-lasting and more susceptible to ligand-promoted dissolution than previously expected.

Peltier, E.; Van Der Lelie, D; Sparks, D

2010-01-01T23:59:59.000Z

187

Woven heat exchanger  

DOE Patents (OSTI)

This invention relates to a heat exchanger for waste heat recovery from high temperature industrial exhaust streams. In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

Piscitella, R.R.

1984-07-16T23:59:59.000Z

188

Electrolyte membrane, methods of manufacture thereof and articles comprising the same  

DOE Patents (OSTI)

Disclosed herein is a method of forming an electrolyte membrane comprising forming a mixture; the mixture comprising a polyhydroxy compound, an aromatic polyhalide compound and an alkali metal hydroxide; disposing the mixture on a porous substrate; reacting the mixture to form a crosslinked proton conductor; and sulfonating the proton conductor. Disclosed herein too is an article comprising a porous substrate; and a sulfonated crosslinked proton conductor disposed within pores of the porous substrate.

Tamaki, Ryo; Rice, Steven Thomas; Yeager, Gary William

2013-11-05T23:59:59.000Z

189

Membrane-patch Excision  

Science Journals Connector (OSTI)

Mechanical manipulation of the cell using glass micropipettes that leads to the extraction of a narrow region of cell membrane. The excision can lead to an isolated membrane patch in which the side of the membran...

2009-01-01T23:59:59.000Z

190

Membrane cleaning in membrane bioreactors: A review  

Science Journals Connector (OSTI)

Abstract Membrane bioreactors (MBRs) have been widely used in wastewater treatment and reclamation. Membrane cleaning is an essential part during the operation of \\{MBRs\\} since membrane fouling is an unavoidable problem. In past decades, with the in-depth understanding on membrane fouling, significant advances in membrane cleaning have been achieved. However, a comprehensive review on membrane cleaning in \\{MBRs\\} is still lacking. This paper attempts to critically review the recent developments of membrane cleaning. Firstly, the fouling and cleaning fundamentals are addressed, and then a comprehensive review on physical, chemical, and biological/biochemical cleaning is presented. The procedures of determining proper cleaning protocols for MBR systems are also proposed. Finally, the existing challenges and future research efforts are discussed in order to ensure the development of membrane cleaning toward a more effective and sustainable way in MBRs.

Zhiwei Wang; Jinxing Ma; Chuyang Y. Tang; Katsuki Kimura; Qiaoying Wang; Xiaomeng Han

2014-01-01T23:59:59.000Z

191

Combined Utilization of Cation Exchanger and Neutral Receptor to Volume Reduction of Alkaline Tank Waste by Separation of Sodium Salts  

SciTech Connect

In this report, novel approaches to the selective liquid-liquid extraction separation of sodium hydroxide and sodium nitrate from high-level alkaline tank waste will be discussed. Sodium hydroxide can be successfully separated from alkaline tank-waste supernatants by weakly acidic lipophilic hydroxy compounds via a cation-exchange mechanism referred to as pseudo hydroxide extraction. In a multi-cycle process, as sodium hydroxide in the aqueous phase becomes depleted, it is helpful to have a neutral sodium receptor in the extraction system to exploit the high nitrate concentration in the waste solution to promote sodium removal by an ion-pair extraction process. Simultaneous utilization of an ionizable organic hydroxy compound and a neutral extractant (crown ether) in an organic phase results in the synergistic enhancement of ion exchange and improved separation selectivity due to the receptor's strong and selective sodium binding. Moreover, combination of the hydroxy compound and the crown ether provides for mutually increased solubility, even in a non-polar organic solvent. Accordingly, application of Isopar{reg_sign} L, a kerosene-like alkane solvent, becomes feasible. This investigation involves examination of such dual-mechanism extraction phases for sodium extraction from simulated and actual salt cake waste solutions. Sodium salts can be regenerated upon the contact of the loaded extraction phases with water. Finally, conditions of potential extraction/strip cycling will be discussed.

Levitskaia, Tatiana G.; Lumetta, Gregg J.; Moyer, Bruce A.

2004-03-29T23:59:59.000Z

192

Microcomposite Fuel Cell Membranes  

Energy.gov (U.S. Department of Energy (DOE))

Summary of microcomposite fuel cell membrane work presented to the High Temperature Membrane Working Group Meeting, Orlando FL, October 17, 2003

193

Membrane-Transistor Cable  

Science Journals Connector (OSTI)

Membrane-Transistor Cable ... The system is the basis for a development of bioelectronic transducers and for the study of nonlinear phenomena in membrane cables. ...

Marion Rentschler; Peter Fromherz

1998-01-20T23:59:59.000Z

194

Ammonia synthesis by N2 and steam electrolysis in molten hydroxide suspensions of nanoscale Fe2O3  

Science Journals Connector (OSTI)

...hydroxide suspensions of nanoscale Fe2O3 10.1126/science.1254234...hydroxide suspension of nano-Fe2O3. At 200°C in an electrolyte with...loaded into carbon black as an anode, again at a low rate; note that tin...which consumed water at the anode and air at the cathode at 0...

Stuart Licht; Baochen Cui; Baohui Wang; Fang-Fang Li; Jason Lau; Shuzhi Liu

2014-08-08T23:59:59.000Z

195

Synthesis of an un-supported, high-flow ZSM-22 zeolite membrane  

DOE Patents (OSTI)

Novel methods for synthesizing wholly un-supported, high-flow catalytic membranes consisting of 100% crystalline ZSM-22 crystals with no binder phase, having sufficient porosity to allow high Weight Hourly Space Velocities of feedstock to pass through without generating back pressure. The ZSM-22 membranes perform favorably to existing bulk ZSM-22 catalysts (e.g., via 1-butene conversion and selectivity). The method of membrane synthesis, based on Vapor Phase Transport, allows free-standing, binder-less membranes to be fabricated in varied geometries and sizes so that membranes can be tailor-made for particular geometries applications. The ZSM-22 precursor gel may be consolidated into a semi-cohesive body prior to vapor phase crystallization, for example, by uniaxial pressing. These crystalline membranes may be modified by ion exchange, pore ion exchange, framework exchange, synthesis modification techniques to incorporate other elements into the framework, such as K, H, Mg, Zn, V, Ga, and Pt.

Thoma, Steven G. (Albuquerque, NM); Nenoff, Tina M. (Albuquerque, NM)

2006-10-10T23:59:59.000Z

196

Nanoporous Hollow Transition Metal Chalcogenide Nanosheets Synthesized via the Anion-Exchange Reaction of Metal Hydroxides with Chalcogenide Ions  

Science Journals Connector (OSTI)

Department of Chemistry, School of Science, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China ... This work was financially supported by the National Natural Science Foundation of China (No. 21422104 and No. 21373149) and the Innovation Foundation of Tianjin University. ... With the great advances in material science and nanotechnol., porous Pt-based nanomaterials with well-controlled compn., shape, and geometrical configuration have been rationally designed and fabricated. ...

Weiwei Zhao; Chao Zhang; Feiyang Geng; Sifei Zhuo; Bin Zhang

2014-10-06T23:59:59.000Z

197

Empirical electronic polarizabilities in oxides, hydroxides, oxyfluorides, and oxychlorides  

Science Journals Connector (OSTI)

An extensive set of infinite-wavelength refractive indices recently derived from a single-oscillator Sellmeier equation [J. Phys. Chem. Ref. Data 31, 931 (2002)] was used to obtain mean total polarizabilities for 340 oxides, 3 hydroxides, 46 oxyhydroxides, 10 oxyfluorides, 8 oxychlorides, 80 hydrates, and 51 fluorides. These data, in conjunction with the polarizability additivity rule and a least-squares procedure, were used to obtain electronic polarizabilities for 79 cations, H2O, and 4 anions (F?,Cl?,OH?,O2?). Using literature values for free-cation polarizabilities, neglecting cation coordination, and allowing the variation of anion polarizability according to log??=log??o?No?Van2?3 where ??=anion polarizability, ??o=empirical free-anion polarizability, Van=anion molar volume and No=a constant, the refinement gives agreement (±5%) in only 92 out of 381 total mean polarizabilities of 252 compounds. Varying cation polarizabilities, but still neglecting dependencies on cation coordination numbers (CN), allowed us to reproduce total polarizability values to within 5% for 611 out of 650 data on 487 oxides, hydrates, oxyfluorides, and oxychlorides. In the next stage we modified a light-scattering (LS) model by Jemmer et al. [J. Phys. Chem. A 102, 8377 (1998)] to give the expression ?(CN,R)=[a1+a2CNcae?a3R]?1, where CNca=the number of nearest-neighbor ions (cation-anion interactions); R=cation-anion interatomic distance; and a1, a2, and a3 are constants. This expression provides for a smooth decrease in polarizability at low CN’s to the free-cation value at infinite CN’s (R=?). Fitting polarizability values for Mg, Ca, Sr, Ba, Pb, Y, and La to this relationship provided a fit to within 5% of 601 out of 650 data. The final step in the refinement process, which used 534 total polarizabilities from 387 compounds, excluded compounds with (1) sterically strained (SS) structures, (2) corner-shared octahedral (CSO) network and chain structures such as perovskites, tungsten bronzes, and titanite-related structures, and (3) piezoelectric (PZ) and/or pyroelectric (PY) structures with abnormally high deviations of observed from total calculated polarizabilities. This final refinement, which provides 79 cation polarizabilities with values for Li, Mg, Ca, Sr, Ba, Pb, B, Al, Ga, Sc, Y, Lu?La, Ge, and Ti in varying CN’s, shows a standard deviation of 0.150 and no discrepancies >4%. Systematic comparisons of differences (?Z*) of Born effective charges (Z*) from formal valence values with deviations of certain ions in ?-r3 plots and with differences between empirical and free-ion ?’s indicate good correlations with metal d-oxygen p-hybridization and covalence. The level of differences increases in the order alkali ions ? alkaline earth ions ? transition metal ions such as Ni2+,Mn2+,Cd2+,Pb2+,Fe3+,andCr3+?M ions found in AMO3 perovskites where M=Ti4+,Zr4+,Nb5+,andTa5+. We ascribe the differences between our empirical polarizabilities and the free-ion values to charge transfer, effectively increasing cation polarizabilities and decreasing anion polarizabilities. Systematic discrepancies are associated with compounds having SS, CSO, and PZ/PY structures. Underbonded cations such as Mg in Mg3Al2Si3O12 (garnet) lead to augmented cation polarizabilities that result in increased observed total calculated polarizabilities (up to 6%). Conversely, overbonded cations in the KClO4 structure lead to diminished cation polarizabilities and decreased observed total calculated polarizabilities. Deviations, ?, (up to 10%) of observed from total calculated polarizabilities are found in perovskite compounds such as SrTiO3. The octahedral corner-sharing and Mn+-O2?-Mn+ one-dimensional chains lead to enhanced covalency accompanying the Mnd?O2p hybridization that, in turn, leads to augmented total polarizabilities and refractive indices. Both (+) and (?) deviations from additivity in piezoelectric (PZ) and/or pyroelectric (PY) structures are caused by (1) underbonded cations in SS and enhanced Mnd?O

Robert D. Shannon and Reinhard X. Fischer

2006-06-15T23:59:59.000Z

198

Interfacial Effects in Iron-Nickel Hydroxide–Platinum Nanoparticles Enhance Catalytic Oxidation  

Science Journals Connector (OSTI)

...coordinatively unsaturated iron sites for activating O 2...the catalyst. To create the iron (hydr)oxide interface...acac) 2 (where acac is acetylacetonate) in the presence of CO...showed that this layer contained iron (fig. S3). Although the...

Guangxu Chen; Yun Zhao; Gang Fu; Paul N. Duchesne; Lin Gu; Yanping Zheng; Xuefei Weng; Mingshu Chen; Peng Zhang; Chih-Wen Pao; Jyh-Fu Lee; Nanfeng Zheng

2014-05-02T23:59:59.000Z

199

Soft Chemical Conversion of Layered Double Hydroxides to Superparamagnetic Spinel Platelets  

E-Print Network (OSTI)

magnetic materials. Introduction The layered double hydroxides (LDHs) and brucite-type divalent metal. Recent advances in the synthesis of highly crystalline LDH and brucite-type platelets of various LDHs and brucite-type structures as extremely well-defined, single crystalline platelets

200

Synergistic flame retardant effect of metal hydroxide and nanoclay in EVA composites  

Science Journals Connector (OSTI)

This study focused on the flame retardancy of ethylene-vinyl acetate copolymer (EVA) in combination with metal hydroxide and nanoclay. Fire tests, such as limiting oxygen index (LOI), flammability (UL-94), cone calorimeter, and smoke density chamber were employed to evaluate the effect of composition variation for the metal hydroxide and the nanoclay in EVA composites. The experimental results showed that when the nanoclay of 1 or 2 weight per cent was substituted for the aluminum hydroxide or magnesium hydroxide in EVA blends, the LOI value was significantly improved while the V-0 rating was maintained. The data obtained from the cone calorimeter test indicated that the peak heat release rate (pk-HRR) is reduced by about 28%–47%. The smoke density data (maximal smoke density, Dm) showed a reduction by about 16%–25%. The thermogravimetric analysis (TGA) data also showed that the nanoclay increased the thermal stability and char residue of the EVA samples. Hence, it is suggested that the metal oxide layer on the burning surface is reinforced by the formation of silicate layer, which is both structured and compacted and acts as the insulation, and the newly formed layer responds to the synergistic effect of flame retardancy as well as smoke suppression observed in the EVA blends.

Ynh-Yue Yen; Hsin-Ta Wang; Wen-Jen Guo

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Aging of Iron (Hydr)oxides by Heat Treatment and Effects on Heavy  

E-Print Network (OSTI)

)oxides are used to remove heavy metals from wastewater and in the treatment of air pollution control residuesAging of Iron (Hydr)oxides by Heat Treatment and Effects on Heavy Metal Binding M E T T E A . S Ã? R generated in waste incineration. In this study, iron oxides containing heavy metals (e.g., Pb, Hg, Cr

Frenkel, Anatoly

202

Factors Affecting Ni and Zn Hydroxide Precipitate Formation in Soils. (S02-peltier222185-oral)  

E-Print Network (OSTI)

Factors Affecting Ni and Zn Hydroxide Precipitate Formation in Soils. (S02-peltier222185-oral) Authors: E.F. Peltier* - Univ. of Delaware D.L. Sparks - Univ. of Delaware Abstract: The formation matter in the soil. Speaker Information: Edward Peltier, Univ. of Delaware, Dept. of Plant and Soil

Sparks, Donald L.

203

Separation and Fixation of Carbon Dioxide Using Polymeric Membrane Contactor  

NLE Websites -- All DOE Office Websites (Extended Search)

National Natural Science Foundation of China. National Natural Science Foundation of China. Separation and Fixation of Carbon Dioxide Using Polymeric Membrane Contactor Zhikang XU, Jianli WANG, Wei CHEN, Youyi XU Institute of Polymer Science, Zhejiang University, 310027, Hangzhou, P. R. China Tel: +86-571-7951342-8218, E-mail: xuzk@ipsm.zju.edu.cn ABSTRACT: Polypropylene hollow fiber membrane (PPHFM) contactor, with aqueous solution absorbent such as sodium hydroxide (NaOH), monoethanolamine (MEA) and diethanolamine (DEA), was designed and used to separate and fix CO 2 from CO 2 /N 2 gas mixtures. The factors that influence the separation properties of CO 2 /N 2 were investigated. It was found that the CO 2 removal efficiency is the best by using MEA solution as absorbent. The overall mass transfer coefficient (K) increases

204

Fuel Cell Technologies Office: High Temperature Membrane Working Group  

NLE Websites -- All DOE Office Websites (Extended Search)

High Temperature Membrane Working Group High Temperature Membrane Working Group The High Temperature Membrane Working Group consists of government, industry, and university researchers interested in developing high temperature membranes for fuel cells. Description Technical Targets Meetings Contacts Description Polymer electrolyte membrane (PEM) fuel cells typically operate at temperatures no higher than 60°C-80°C due to structural limitations of the membrane. Operating PEM fuel cell stacks at higher temperatures (120°C for transportation and 150°C for stationary applications), however, would yield significant energy benefits. For example, heat rejection is easier at higher temperatures, which would allow use of smaller heat exchangers in fuel cell power systems. In addition, for reformate fuel cell systems, carbon monoxide (CO) tolerance of the stack is less problematic at higher temperatures, which would reduce the size requirements or possibly eliminate the need for some CO clean-up beds in the fuel processor.

205

Thermodynamic Modeling of a Membrane Dehumidification System  

E-Print Network (OSTI)

by various industries: microfiltration, ultrafiltration, reverse osmosis, and electrodialysis [1]. In addition to these well established and common processes, two additional processes are increasingly being applied by industry: pervaporation and gas... of anion and cation exchange membranes. Electrodialysis is also commonly used in desalination processes and in the food industry [5]. Pervaporation is similar to both reverse osmosis and gas separation (discussed in the next section). Pervaporation...

Bynum, John 1983-

2012-11-28T23:59:59.000Z

206

Sulfonated Polybenzophenone/Poly(arylene ether) Block Copolymer Membranes for Fuel Cell Applications  

Science Journals Connector (OSTI)

Major car companies have announced that they will commercialize fuel cell vehicles from 2015. ... Future articles will describe the performance of these copolymers as proton-exchange membranes in hydrogen/air and direct methanol fuel cells. ...

Takahiro Miyahara; Tetsuji Hayano; Soichi Matsuno; Masahiro Watanabe; Kenji Miyatake

2012-06-12T23:59:59.000Z

207

Journal of Membrane Science 332 (2009) 8992 Contents lists available at ScienceDirect  

E-Print Network (OSTI)

C. McDonalda, , David W. Gidleyb , Tracy Sandersonb , Richard S. Valleryb a Giner, Inc., 89 Rumford 2009 Accepted 25 January 2009 Available online 5 February 2009 Keywords: Proton-exchange membrane Pore

Gidley, David

208

Alternative Sodium Recovery Technology—High Hydroxide Leaching: FY10 Status Report  

SciTech Connect

Boehmite leaching tests were carried out at NaOH concentrations of 10 M and 12 M, temperatures of 85°C and 60°C, and a range of initial aluminate concentrations. These data, and data obtained during earlier 100°C tests using 1 M and 5 M NaOH, were used to establish the dependence of the boehmite dissolution rate on hydroxide concentration, temperature, and initial aluminate concentration. A semi-empirical kinetic model for boehmite leaching was fitted to the data and used to calculate the NaOH additions required for leaching at different hydroxide concentrations. The optimal NaOH concentration for boehmite leaching at 85°C was estimated, based on minimizing the amount of Na that had to be added in NaOH to produce a given boehmite conversion.

Mahoney, Lenna A.; Neiner, Doinita; Peterson, Reid A.; Rapko, Brian M.; Russell, Renee L.; Schonewill, Philip P.

2011-02-04T23:59:59.000Z

209

Electron-gas model for molecular crystals. Application to the alkali and alkaline-earth hydroxides  

Science Journals Connector (OSTI)

A theoretical model for calculating the structure and energy of molecular crystals is presented. The model, which requires no empirical parameters, is based on the Gordon-Kim electron-gas model. Many-body effects are incorporated through the mutual overlap of the electronic distributions of all molecules or ions in the neighborhood of a given point in the crystal. Effects of the crystal environment on the molecular properties are approximated by inclusion of an electrostatic potential that mimics the crystal potential in ab initio calculations on the individual component molecules or ions in the crystal. Application is made to a number of alkali and alkaline-earth hydroxide crystals in which the components are taken to be hydroxide ions, and alkali or alkaline-earth cations. The agreement with experiment is good (within 2.5% in lattice constants and 1.1% in lattice dissociation energy). The calculated changes in molecular dipole moment are between 20 and 40%.

R. LeSar and R. G. Gordon

1982-06-15T23:59:59.000Z

210

Setting process of lime-based conservation mortars with barium hydroxide  

SciTech Connect

This paper presents the effect of barium hydroxide on the setting mechanism of lime-based conservation mortars, when used as an additive material. The study focuses on the monitoring of the setting process and the identification of the mineral phases formed, which are essential for furthering the study of the durability of barium mixtures against chemical degradation. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and thermal analysis (DTA-TG) were used to monitor the setting processes of these mixtures and identify new phases formed. The results suggest that barium hydroxide is evenly distributed within the lime and produces a homogeneous binding material, consisting of calcite (CaCO{sub 3}), witherite (BaCO{sub 3}) and barium-calcium carbonate [BaCa(CO{sub 3}){sub 2}]. Finally, it was found that barium carbonate can be directly bonded to calcitic aggregates and therefore increases its chemical compatibility with the binding material.

Karatasios, Ioannis [Institute of Materials Science, NCSR Demokritos, Aghia Paraskevi, 153 10 Athens (Greece)]. E-mail: ikarat@ims.demokritos.gr; Kilikoglou, Vassilis [Institute of Materials Science, NCSR Demokritos, Aghia Paraskevi, 153 10 Athens (Greece); Colston, Belinda [Department of Forensic and Biomedical Sciences, University of Lincoln, Lincoln, LN6 7TS (United Kingdom); Theoulakis, Panagiotis [Department of Conservation of Antiquities and Works of Art, TEI of Athens, Athens, 122 10 (Greece); Watt, David [Hutton and Rostron Environmental Investigations Limited/Centre for Sustainable Heritage, University College London (United Kingdom)

2007-06-15T23:59:59.000Z

211

Honeywell Modular Automation System Computer Software Documentation for the Magnesium Hydroxide Precipitation Process  

SciTech Connect

The purpose of this Computer Software Document (CSWD) is to provide configuration control of the Honeywell Modular Automation System (MAS) in use at the Plutonium Finishing Plant (PFP) for the Magnesium Hydroxide Precipitation Process in Rm 23OC/234-52. This CSWD describes hardware and PFP/FFS developed software for control of Magnesium Hydroxide Precipitation process located in room 230, 234-52. The Honeywell and Plant Scape software generate limited configuration reports for the developed control software. These reports are described in the following section and are attached as addendum's. This plan applies to PFP Engineering Manager, Thermal Stabilization Cognizant Engineers, Solutions Stabilization Engineers, and the Shift Technical Advisors responsible for the Honeywell MAS software/hardware and administration of the Honeywell System.

STUBBS, A.M.

2001-02-01T23:59:59.000Z

212

Composite zeolite membranes  

DOE Patents (OSTI)

A new class of composite zeolite membranes and synthesis techniques therefor has been invented. These membranes are essentially defect-free, and exhibit large levels of transmembrane flux and of chemical and isotopic selectivity.

Nenoff, Tina M. (Albuquerque, NM); Thoma, Steven G. (Albuquerque, NM); Ashley, Carol S. (Albuquerque, NM); Reed, Scott T. (Albuquerque, NM)

2002-01-01T23:59:59.000Z

213

Membrane Technology Workshop  

Energy.gov (U.S. Department of Energy (DOE))

At the Membrane Technology Workshop (held July 24, 2012, in Rosemont, IL), stakeholders from industry and academia explored the status of membrane research and development (R&D). Participants...

214

Membrane Technology Workshop  

Energy.gov (U.S. Department of Energy (DOE))

At the Membrane Technology Workshop (held July 24, 2012, in Rosemont, IL), stakeholders from industry and academia explored the status of membrane research and development (R&D). Participants ...

215

Hybrid adsorptive membrane reactor  

DOE Patents (OSTI)

A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

Tsotsis, Theodore T. (Huntington Beach, CA); Sahimi, Muhammad (Altadena, CA); Fayyaz-Najafi, Babak (Richmond, CA); Harale, Aadesh (Los Angeles, CA); Park, Byoung-Gi (Yeosu, KR); Liu, Paul K. T. (Lafayette Hill, PA)

2011-03-01T23:59:59.000Z

216

Supertubes and Superconducting Membranes  

SciTech Connect

We show the equivalence between configurations that arise from string theory of type IIA, called supertubes, and superconducting membranes at the bosonic level. We find equilibrium and oscillating configurations for a tubular membrane carrying a current along its axis.

Cordero, Ruben; Miguel-Pilar, Zelin [Departamento de Fisica, Escuela Superior de Fisica y Matematicas del IPN, Edificio 9, Unidad Profesional 'Adolfo Lopez Mateos', Zacatenco, 07738 Mexico D.F. (Mexico)

2007-02-09T23:59:59.000Z

217

Recycling of oleochemical wastewater for boiler feed water using reverse osmosis membranes — A case study  

Science Journals Connector (OSTI)

Currently, awareness of water conservation has increased worldwide due to water scarcity. Wastewater recycling appears to be attractive for water conservation. This paper addresses a case study of oleochemical wastewater treatment using an advanced process that comprises ultrafiltration (UF) and reverse osmosis (RO) membranes. Prior to the membrane process, the oleochemical effluent was first treated using a biological treatment system that was installed by the factory owner. The quantity and quality of the permeate stream of the membrane system were then periodically monitored over 43 days. The results showed that the system functioned effectively in reducing the chemical oxygen demand (COD), hardness content and the amount of total dissolved solids (TDS). However, the system started to deteriorate after 15 days of operation. Membrane biofouling was suspected to have occurred in the RO membrane. Nevertheless, the fouling problem could be resolved by chemically cleaning the RO membrane using a sodium hydroxide (NaOH) solution every 3–5 days. Despite of the fact that data set for a longer period is needed to provide a more comprehensive study on the biofouling mechanism of membrane, this study somehow reflects a real-life problem of the application of RO membrane in the water recycling industry in Malaysia.

Chai Hoon Koo; Abdul Wahab Mohammad; Fatihah Suja'

2011-01-01T23:59:59.000Z

218

Proton Exchange Membrane Fuel Cells for Electrical Power Generation...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

ft 3 ). Figure and data from 34. ... 45 11 Figure 14: The compressed gas hydrogen tanks from Lincoln Composites (left) and Quantum Technologies (right)....

219

Mathematical modeling of polymer exchange membrane fuel cells.  

E-Print Network (OSTI)

??Fuel cells are predicted to be the power delivery devices of the future. They have many advantages such as the wide fuel selection, high energy… (more)

Spiegel, Colleen

2008-01-01T23:59:59.000Z

220

Physical Chemistry Research Toward Proton Exchange Membrane Fuel Cell Advancement  

Science Journals Connector (OSTI)

He obtained his Ph.D. in semiconductor electrochemistry from Southampton University in 1987, and since 1994, he has worked on fuel cell electrochemistry and the development of oxygen reduction catalysts for automotive applications for Ballard and then AFCC. ... More work is needed to better understand electrocatalysts generally in terms of properties and characterization. ... Such lessons from PEMFC research are relevant to other electrochemical conversion systems, including Li–air batteries and flow batteries. ...

Karen E. Swider-Lyons; Stephen A. Campbell

2013-01-10T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Membrane Separations Research  

E-Print Network (OSTI)

MEMBRANE SEPARATIONS RESEARCH James R. Fair Chemical Engineering Department The University of Texas at Austin Austin, TX 78712 ABSTRACT The use of membranes for separating gaseous and liquid mixtures has grown dramatically in the past 15... years. Applications have been dominated by light gas separations and water purification. During this pioneering period, equipment containing the membrane suIfaces has been developed to a point where failures are minimal and the membranes themselves...

Fair, J. R.

222

Membrane Technology Workshop  

Energy.gov (U.S. Department of Energy (DOE))

Presentation by Charles Page (Air Products & Chemicals, Inc.) for the Membrane Technology Workshop held July 24, 2012

223

Polyphosphazene semipermeable membranes  

DOE Patents (OSTI)

A semipermeable, inorganic membrane is disclosed; the membrane is prepared from a phosphazene polymer and, by the selective substitution of the constituent groups bound to the phosphorous in the polymer structure, the selective passage of fluid from a feedstream can be controlled. Resistance to high temperatures and harsh chemical environments is observed in the use of the phosphazene polymers as semipermeable membranes.

Allen, Charles A. (Idaho Falls, ID); McCaffrey, Robert R. (Idaho Falls, ID); Cummings, Daniel G. (Idaho Falls, ID); Grey, Alan E. (Idaho Falls, ID); Jessup, Janine S. (Darlington, ID); McAtee, Richard E. (Idaho Falls, ID)

1988-01-01T23:59:59.000Z

224

Architecture on Exchange InternationalExchangeProgram  

E-Print Network (OSTI)

. Previous students have attended: · McMaster University, Canada · Malmö University, Sweden · University of Leeds, United Kingdom · Northeastern University, USA · Purdue University, USA · University of California on page 2 5 International Office Study Abroad and Exchange Program Level 4, Jane Foss Russell Building (G

Viglas, Anastasios

225

Agriculture on Exchange InternationalExchangeProgram  

E-Print Network (OSTI)

-wide exchange destinations for Agriculture majors include: Canada....................McGill University, Faculty of Arts (AgEc only) (www.umanitoba.ca) United Kingdom.....University of Leeds, School of Earth and Environment (www.leeds.ac.uk) .................................University of Nottingham, School of Biosciences

Viglas, Anastasios

226

The Bioenergetic Description of Light Energy Migration in Photoactive Membranes; Equivalence between the Theory of the Energy Fluxes and the Theory of the Proportion of Pigments Forms to Total Pigments  

Science Journals Connector (OSTI)

The energy exchanges between pigments in biological membranes irradiated with light can be described in a number of ... , is equivalent to the theory of the energy exchange fluxes developed by Strasser (1978). .....

C. Sironval; R. Strasser; M. Brouers

1984-01-01T23:59:59.000Z

227

Nitrogen Front Evolution in Purged Polymer Electrolyte Membrane Fuel Cell with Dead-Ended Anode  

E-Print Network (OSTI)

Nitrogen Front Evolution in Purged Polymer Electrolyte Membrane Fuel Cell with Dead-Ended Anode and experimentally verify the evolution of liquid water and nitrogen fronts along the length of the anode channel in a proton exchange membrane fuel cell operating with a dead-ended anode that is fed by dry hydrogen

Stefanopoulou, Anna

228

A HYBRID ADSORBENT-MEMBRANE REACTOR (HAMR) SYSTEM FOR HYDROGEN PRODUCTION  

E-Print Network (OSTI)

hydrogen production for proton exchange membrane (PEM) fuel cells for various mobile and stationaryA HYBRID ADSORBENT-MEMBRANE REACTOR (HAMR) SYSTEM FOR HYDROGEN PRODUCTION A. Harale, H. Hwang, P recently our focus has been on new HAMR systems for hydrogen production, of potential interest to pure

Southern California, University of

229

Enhanced membrane gas separations  

SciTech Connect

An improved membrane gas separation process is described comprising: (a) passing a feed gas stream to the non-permeate side of a membrane system adapted for the passage of purge gas on the permeate side thereof, and for the passage of the feed gas stream in a counter current flow pattern relative to the flow of purge gas on the permeate side thereof, said membrane system being capable of selectively permeating a fast permeating component from said feed gas, at a feed gas pressure at or above atmospheric pressure; (b) passing purge gas to the permeate side of the membrane system in counter current flow to the flow of said feed gas stream in order to facilitate carrying away of said fast permeating component from the surface of the membrane and maintaining the driving force for removal of the fast permeating component through the membrane from the feed gas stream, said permeate side of the membrane being maintained at a subatmospheric pressure within the range of from about 0.1 to about 5 psia by vacuum pump means; (c) recovering a product gas stream from the non-permeate side of the membrane; and (d) discharging purge gas and the fast permeating component that has permeated the membrane from the permeate side of the membrane, whereby the vacuum conditions maintained on the permeate side of the membrane by said vacuum pump means enhance the efficiency of the gas separation operation, thereby reducing the overall energy requirements thereof.

Prasad, R.

1993-07-13T23:59:59.000Z

230

NETL: Novel Polymer Membrane Process for Pre-Combustions CO2 Capture from  

NLE Websites -- All DOE Office Websites (Extended Search)

Polymer Membrane Process for Pre-Combustions CO2 Capture from Coal-Fired Syngas Polymer Membrane Process for Pre-Combustions CO2 Capture from Coal-Fired Syngas Project No.: DE-FE0001124 Membrane Technology Research (MTR) is developing a high-temperature stable polymer membrane to separate hydrogen from carbon dioxide (H2/CO2). MTR will investigate novel high-temperature-stable polymers identified by Tetramer for use in H2/CO2 selective membranes. They will also conduct bench-scale testing of optimized membranes and membrane modules with simulated syngas to evaluate the membrane performance and lifetime under expected operating conditions. The advantages of this technology are that the process can be done warm/hot to reduce the need for heat exchange and nitrogen sweep can be used to maintain permeate fuel gas at turbine pressure.

231

Polyelectrolyte complex/PVA membranes for diffusion dialysis  

Science Journals Connector (OSTI)

Abstract Polyelectrolyte complexes (PECs)/polyvinyl alcohol (PVA) membranes are prepared from PVA, anion exchange and cation exchange multisilicon copolymers, which contain plenty of functional groups of OH, N+(CH3)3/Si(OCH3)3, and SO3Na/Si(OCH3)3, respectively. The OH and Si(OCH3)3 groups can undertake sol–gel reaction to form crosslinking structure, while the N+(CH3)3 and \\{SO3Na\\} groups can be combined through electrostatic interaction. The PECs/PVA membranes exhibit improved thermal stability, swelling resistance and flexibility as compared with single anion or cation exchange hybrid membranes. The PECs/PVA membranes have the water uptakes (WR) of 25.3–70.4%, initial decomposition temperatures (IDTs) of 246–285 °C, tensile strength of 23.1–33.8 MPa, and elongation at break of 3.5–13.1%. The membranes can be potentially applied for both acid and alkali recovery through diffusion dialysis (DD) process. The separation factor (S) for HCl/FeCl2 mixture can reach up to 89.9, which is about five times higher than that of commercial DF-120 membrane (18.5 at 25 °C). The dialysis coefficients of NaOH (UOH) are in the range of 0.014–0.019 m/h, around 7–9 times higher than the value of commercial SPPO membrane (0.002 m/h at 25 °C). The membranes also show potential usefulness for industrial acidic and alkali wastes treatment.

Cong Wang; Cuiming Wu; Yonghui Wu; Jingjing Gu; Tongwen Xu

2013-01-01T23:59:59.000Z

232

Wound tube heat exchanger  

DOE Patents (OSTI)

What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

233

Green Exchange | Open Energy Information  

Open Energy Info (EERE)

Exchange Place: New York, New York Zip: NY 10282 Product: String representation "The Green Excha ... es marketplace." is too long. References: Green Exchange1 This article is a...

234

Evaluation of electrodialysis for scaling prevention of nanofiltration membranes at high water recoveries  

Science Journals Connector (OSTI)

The water recovery of nanofiltration in drinking water production is limited to 80–85%. When the water recovery is increased, there is a risk of scaling of sparingly soluble salts, such as CaSO4 or CaCO3, onto the membrane surface. There is a need for robust technologies that handle the problem of mineral scaling in nanofiltration and reverse osmosis, allowing operation at higher recoveries, i.e., with a higher production of potable water. In this study, the retentate stream of a nanofiltration unit was therefore desalinated by electrodialysis. Two different ion exchange membrane pairs, namely AMX-CMX (Neosepta, Japan) and FTAM-FTCM (Fumasep, Germany) were used for this purpose. The membrane pairs were compared on the basis of their removal efficiency of the main ions present in natural waters, with special attention to calcium and sulphate ions. The economic feasibility of retentate treatment by electrodialysis is discussed as well. The FTAM anion exchange membranes of Fumasep were able to remove sulphate ions faster, relative to chloride or nitrate ions. This is unexpected, because sulphate ions have a high hydrated ionic radius and steric hindrance typically obstructs their transport through anion exchange membranes, as is the case with the AMX membranes. This feature makes the FTAM membranes appropriate for the desalination of retentate streams of nanofiltration and reverse osmosis membranes, in water recycling applications. The other membranes can be regarded as non-selective.

Steven Van Geluwe; Leen Braeken; Thomas Robberecht; Maarten Jans; Claude Creemers; Bart Van der Bruggen

2011-01-01T23:59:59.000Z

235

Influence of electrolytes and membranes on cell operation for syn-gas production  

SciTech Connect

The impact of membrane type and electrolyte composition for the electrochemical generation of synthesis gas (CO + H2) using a Ag gas diffusion electrode are presented. Changing from a cation exchange membrane to an anion exchange membrane (AEM) extended the cell operational time at low Ecell values (up to 4x) without impacting product composition. The use of KOH as the catholyte decreased the Ecell and resulted in a minimum electrolyte cost reduction of 39%. The prime factor in determining operational time at low Ecell values was the ability to maintain a sufficiently high anolyte pH.

Eric J. Dufek; Tedd E. Lister; Michael E. McIlwain

2012-02-01T23:59:59.000Z

236

Active microchannel heat exchanger  

DOE Patents (OSTI)

The present invention is an active microchannel heat exchanger with an active heat source and with microchannel architecture. The microchannel heat exchanger has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat exchanger chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat exchanger chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.

Tonkovich, Anna Lee Y. (Pasco, WA) [Pasco, WA; Roberts, Gary L. (West Richland, WA) [West Richland, WA; Call, Charles J. (Pasco, WA) [Pasco, WA; Wegeng, Robert S. (Richland, WA) [Richland, WA; Wang, Yong (Richland, WA) [Richland, WA

2001-01-01T23:59:59.000Z

237

Technology Performance Exchange  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Technology Performance Exchange Technology Performance Exchange TDM - Jason Koman (BTO) TDM - Dave Catarious (FEMP) William Livingood National Renewable Energy Laboratory William.Livingood@nrel.gov 303-384-7490 April 2, 2013 2 | Building Technologies Office eere.energy.gov Purpose & Objectives Problem: Perceived fiscal risk associated with the installation of unfamiliar technologies impedes adoption rates for cost-effective, energy-saving products. Impact of Project: Enable end users to quickly and

238

Substituted polyacetylene separation membrane  

DOE Patents (OSTI)

A separation membrane is described which is useful for gas separation, particularly separation of C{sub 2+} hydrocarbons from natural gas. The invention encompasses the membrane itself, methods of making it and processes for using it. The membrane comprises a polymer having repeating units of a hydrocarbon-based, disubstituted polyacetylene, having the general formula shown in the accompanying diagram, wherein R{sub 1} is chosen from the group consisting of C{sub 1}-C{sub 4} alkyl and phenyl, and wherein R{sub 2} is chosen from the group consisting of hydrogen and phenyl. In the most preferred embodiment, the membrane comprises poly(4-methyl-2-pentyne) [PMP]. The membrane exhibits good chemical resistance and has super-glassy properties with regard to separating certain large, condensable permeant species from smaller, less-condensable permeant species. The membranes may also be useful in other fluid separations. 4 figs.

Pinnau, I.; Morisato, Atsushi

1998-01-13T23:59:59.000Z

239

Substituted polyacetylene separation membrane  

DOE Patents (OSTI)

A separation membrane useful for gas separation, particularly separation of C.sub.2+ hydrocarbons from natural gas. The invention encompasses the membrane itself, methods of making it and processes for using it. The membrane comprises a polymer having repeating units of a hydrocarbon-based, disubstituted polyacetylene, having the general formula: ##STR1## wherein R.sub.1 is chosen from the group consisting of C.sub.1 -C.sub.4 alkyl and phenyl, and wherein R.sub.2 is chosen from the group consisting of hydrogen and phenyl. In the most preferred embodiment, the membrane comprises poly(4-methyl-2-pentyne) ›PMP!. The membrane exhibits good chemical resistance and has super-glassy properties with regard to separating certain large, condensable permeant species from smaller, less-condensable permeant species. The membranes may also be useful in other fluid separations.

Pinnau, Ingo (Palo Alto, CA); Morisato, Atsushi (Tokyo, JP)

1998-01-13T23:59:59.000Z

240

Model Cell Membranes  

Science Journals Connector (OSTI)

... are being used as model systems to test particular hypotheses in membrane transport. Thus, Tosteson and his colleagues (Andreoli et al., J. Gen. PhysioL, 50, 1729; ...

A Correspondent

1968-01-13T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Interconversion of Brucite-like and Hydrotalcite-like Phases in Cobalt Hydroxide Compounds  

Science Journals Connector (OSTI)

Interconversion of Brucite-like and Hydrotalcite-like Phases in Cobalt Hydroxide Compounds ... While ?-Co(OH)2 is prepared with short-aging in nitrogen atmosphere, this divalent metal (Co2+) hydrotalcite-like phase transforms into brucite-like ?-Co(OH)2 under prolonged aging in nitrogen. ... 1-11 In their simplest structure, brucite-like phases form a close-packed array in which a divalent metal cation is located in an octahedral site generated by six hydroxyl oxygen atoms. ...

Z. P. Xu; H. C. Zeng

1998-12-24T23:59:59.000Z

242

Effect of calcium hydroxide and carbonates on IGA and SCC of Alloy 600. Final report. [PWR  

SciTech Connect

A series of five tests was conducted at the Westinghouse Forest Hills Single Tube Model Boiler (STMB) Facility under this project. The objective of the project was to determine if alkaline earth carbonates and/or hydroxides are key ingreidents in causing intergranular attack (IGA) or stress corrosion cracking (SCC) of mill-annealed Alloy 600. Also as part of this program a report was written and issued detailing the earlier related STMB work Westinghouse conducted that led to reproducible SCC. The work reported here was an extension of that work.

Balavage, J.R.

1983-05-01T23:59:59.000Z

243

A new approach to optimize the operating conditions of a polymer electrolyte membrane fuel cell based on degradation mechanisms  

Science Journals Connector (OSTI)

Performance degradation remains as one of the primary limitations ... practical applications of proton exchange membrane (PEM) fuel cells. The performance of a PEM fuel cell stack is affected by many internal and...

Ramin Roshandel; Tarannom Parhizgar

2013-09-01T23:59:59.000Z

244

Wastewater and water treatment: Anion exchange. (Latest citations from the Selected Water Resources Abstracts database). Published Search  

SciTech Connect

The bibliography contains citations concerning the theory and methods of anion exchange in the treatment of potable water and wastewaters. Citations discuss anion exchange resins and membranes, desalination techniques, and process evaluations. Methods for anion analysis using chromatographic techniques are also considered. (Contains a minimum of 74 citations and includes a subject term index and title list.)

Not Available

1993-09-01T23:59:59.000Z

245

Wastewater and water treatment: Anion exchange. (Latest citations from the Selected Water Resources Abstracts database). Published Search  

SciTech Connect

The bibliography contains citations concerning the theory and methods of anion exchange in the treatment of potable water and wastewaters. Citations discuss anion exchange resins and membranes, desalination techniques, and process evaluations. Methods for anion analysis using chromatographic techniques are also considered. (Contains a minimum of 74 citations and includes a subject term index and title list.)

Not Available

1994-01-01T23:59:59.000Z

246

Enhanced thermal- and photo-stability of acid yellow 17 by incorporation into layered double hydroxides  

SciTech Connect

2,5-dichloro-4-(5-hydroxy-3-methyl-4-(sulphophenylazo) pyrazol-1-yl) benzenesulphonate (DHSB) anions, namely acid yellow 17 anions, have been successfully intercalated into Zn-Al layered double hydroxides (LDH) to produce a novel organic-inorganic pigment by a simple method involving separate nucleation and aging steps (SNAS), and the dye-intercalated LDH was analyzed by various techniques, e.g., XRD, SEM, FT-IR, TG-DTA and ICP. The d-spacing of the prepared LDH is 2.09 nm. Furthermore, the incorporation of the DHSB aims to enhance the thermal- and photo-stability of the guest dye molecule, for example, the less color change after accelerated thermal- and photo-aging test. - Graphical abstract: Acid yellow anions were successfully assembled into ZnAl layered double hydroxides (LDH) to produce a novel organic-inorganic composite pigment by a simple method involving separate nucleation and aging steps (SNAS). Highlights: > Acid yellow 17 was directly intercalated into ZnAl-LDH to form a novel pigment. > The pigment was prepared by a method involving separate nucleation and aging steps. > The intercalation of dye anions enhances its thermal- and photo-stability.

Wang Qian; Feng Yongjun; Feng Junting [College of Science, State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Li Dianqing, E-mail: lidq@mail.buct.edu.cn [College of Science, State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

2011-06-15T23:59:59.000Z

247

Electrochemical formation of hydroxide for enhancing carbon dioxide and acid gas uptake by a solution  

DOE Patents (OSTI)

A system for forming metal hydroxide from a metal carbonate utilizes a water electrolysis cell having an acid-producing anode and a hydroxyl-producing cathode immersed in a water solution of sufficient ionic content to allow an electric current to pass between the hydroxyl-producing cathode and the acid-producing anode. A metal carbonate is placed in close proximity to the acid-producing anode. A direct current electrical voltage is provided across the acid-producing anode and the hydroxyl-producing cathode sufficient to generate acid at the acid-producing anode and hydroxyl ions at the hydroxyl-producing cathode. The acid dissolves at least part of the metal carbonate into metal and carbonate ions allowing the metal ions to travel toward the hydroxyl-producing cathode and to combine with the hydroxyl ions to form the metal hydroxide. The carbonate ions travel toward the acid-producing anode and form carbonic acid and/or water and carbon dioxide.

Rau, Gregory Hudson

2014-07-01T23:59:59.000Z

248

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

This report covers the following tasks: Task 1--Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints; Task 2--Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability; Task 3--Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres; Task 4--Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures; Task 5--Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability; and Task 6--Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2002-04-01T23:59:59.000Z

249

Ensure the best performance from membranes and demineralizers  

SciTech Connect

This article discusses how the use of various membrane technologies to provide high-purity water for power generation has increased dramatically in the last 10 years. This trend has been driven primarily by three factors: (1) reduction in costs achieved through reduced chemical, operation, and maintenance requirements; (2) reduction of waste-treatment requirements in response to new environmental legislation; and (3) reduction of man-power requirements for monitoring regeneration of ion-exchange (IX) regenerations. The economic impact of membrane technology applied ahead of a makeup water demineralizer can be illustrated by a series of examples with three different waters, each used at three different flow rates. A cost analysis is provided for each case, before and after backfitting a membrane system. For perspective, the leading membrane technologies are reviewed first.

Strauss, S.D.

1993-03-01T23:59:59.000Z

250

Synthesis and Characterization of Cross?linked Polymer Electrolyte Membranes for Supercapacitor  

Science Journals Connector (OSTI)

Cross?linked polyvinyl alcohol (PVA) electrolyte membranes have been synthesized by using a solution casting method. In this study PVA was blended with oxidative cross?linked agent (zinc acetate) and nano?sized silica as filler to stabilize PVA matrix and enhance conductivity. The cross?linked membranes were immersed into lithium hydroxide (LiOH) aqueous solution to increase their ionic conductivity. Two techniques were used to characterize the resulted membranes including Fourier transform infra red (FTIR) and AC impedance spectroscopies. The results showed that absorption peaks of C?O?C group and Si?O?Si are presence in the FTIR spectra attributed to the cross?linking process. Impedance spectra indicated that the contribution of ionic dopant (LiOH) to enhance conductivity is insignificant. The highest conductivity of the studied cross?linked PVA membrane is 1.34×10 ?3 ? S ? cm ?1 corresponding to 5% LiOH dopant concentration of cross?linked PVA?zinc acetate?nano silica membrane. The present study also suggested that the solution casting is appropriate for cross?linked membrane synthesis.

Memoria Rosi; Muhamad Prama Ekaputra; Mikrajuddin Abdullah; Khairurrijal

2010-01-01T23:59:59.000Z

251

Chemically and compositionally modified solid solution disordered multiphase nickel hydroxide positive electrode for alkaline rechargeable electrochemical cells  

DOE Patents (OSTI)

A high capacity, long cycle life positive electrode for use in an alkaline rechargeable electrochemical cell comprising: a solid solution nickel hydroxide material having a multiphase structure that comprises at least one polycrystalline .gamma.-phase including a polycrystalline .gamma.-phase unit cell comprising spacedly disposed plates with at least one chemical modifier incorporated around the plates, the plates having a range of stable intersheet distances corresponding to a 2.sup.+ oxidation state and a 3.5.sup.+, or greater, oxidation state; and at least one compositional modifier incorporated into the solid solution nickel hydroxide material to promote the multiphase structure.

Ovshinsky, Stanford R. (Bloomfield Hills, MI); Corrigan, Dennis (Troy, MI); Venkatesan, Srini (Southfield, MI); Young, Rosa (Troy, MI); Fierro, Christian (Troy, MI); Fetcenko, Michael A. (Rochester Hills, MI)

1994-01-01T23:59:59.000Z

252

Modeling of durability of polyelectrolyte membrane of O2/H2 fuel cell  

E-Print Network (OSTI)

In this paper, we discuss critical aspects of the mechanisms and features of polymer proton exchange membrane (PEM) degradation in low-temperature H2/O2 fuel cell. In this paper, we focused on chemical mechanism of OH radical generation and their distribution in operational fuel cell. According to the current concept, free radicals are generated from hydrogen and oxygen crossover gases at the surface of Pt particles that precipitated in the membrane. We explicitly calculate Pt precipitation rate and electrochemical potential distribution in the membrane that controls it. Based on radical generation rate and Pt distribution we calculate degradation rate of the membrane taking advantage of simple kinetics equations.

Atrazhev, Vadim V

2014-01-01T23:59:59.000Z

253

Original article Flat ceramic membranes  

E-Print Network (OSTI)

membranes. The orig- inal intellectual concept is protected by two international patents. Strategically of investment and functioning costs while keeping the interest of ceramics. ceramic membrane / plate / tubular

Paris-Sud XI, Université de

254

High Temperature Membrane Working Group  

Energy.gov (U.S. Department of Energy (DOE))

The High Temperature Membrane Working Group consists of government, industry, and university researchers interested in developing high temperature membranes for fuel cells.

255

Ordered ceramic membranes  

SciTech Connect

Ceramic membranes have been formed from colloidal sols coated on porous clay supports. These supported membranes have been characterized in terms of their permeabilities and permselectivities to various aqueous test solutions. The thermal stabilities and pore structures of these membranes have been characterized by preparing unsupported membranes of the correpsonding material and performing N{sub 2} adsorption-desorption and X-ray diffraction studies on these membranes. To date, membranes have been prepared from a variety of oxides, including TiO{sub 2}, SiO{sub 2}, ZrO{sub 2}, and Al{sub 2}O{sub 3}, as well as Zr-, Fe-, and Nb-doped TiO{sub 2}. In many of these membranes pore diameters are less than 2 nm, while in others the pore diameters are between 3 and 5 nm. Procedures for fabricating porous clay supports with reproducible permeabilities for pure water are also discussed. 30 refs., 59 figs., 22 tabs.

Anderson, M.A.; Hill, C.G. Jr.; Zeltner, W.A.

1991-10-01T23:59:59.000Z

256

Catalytic nanoporous membranes  

DOE Patents (OSTI)

A nanoporous catalytic membrane which displays several unique features Including pores which can go through the entire thickness of the membrane. The membrane has a higher catalytic and product selectivity than conventional catalysts. Anodic aluminum oxide (AAO) membranes serve as the catalyst substrate. This substrate is then subjected to Atomic Layer Deposition (ALD), which allows the controlled narrowing of the pores from 40 nm to 10 nm in the substrate by deposition of a preparatory material. Subsequent deposition of a catalytic layer on the inner surfaces of the pores reduces pore sizes to less than 10 nm and allows for a higher degree of reaction selectivity. The small pore sizes allow control over which molecules enter the pores, and the flow-through feature can allow for partial oxidation of reactant species as opposed to complete oxidation. A nanoporous separation membrane, produced by ALD is also provided for use in gaseous and liquid separations. The membrane has a high flow rate of material with 100% selectivity. Also provided is a method for producing a catalytic membrane having flow-through pores and discreet catalytic clusters adhering to the inside surfaces of the pores.

Pellin, Michael J; Hryn, John N; Elam, Jeffrey W

2013-08-27T23:59:59.000Z

257

CENTRIFUGAL MEMBRANE FILTRATION  

SciTech Connect

The overall project consists of several integrated research phases related to the applicability, continued development, demonstration, and commercialization of the SpinTek centrifugal membrane filtration process. Work performed during this reporting period consisted of Phase 2 evaluation of the SpinTek centrifugal membrane filtration technology and Phase 3, Technology Partnering. During Phase 1 testing conducted at the EERC using the SpinTek ST-IIL unit operating on a surrogate tank waste, a solids cake developed on the membrane surface. The solids cake was observed where linear membrane velocities were less than 17.5 ft/s and reduced the unobstructed membrane surface area up to 25%, reducing overall filtration performance. The primary goal of the Phase 2 research effort was to enhance filtration performance through the development and testing of alternative turbulence promoter designs. The turbulence promoters were designed to generate a shear force across the entire membrane surface sufficient to maintain a self-cleaning membrane capability and improve filtration efficiency and long-term performance. Specific Phase 2 research activities included the following: System modifications to accommodate an 11-in.-diameter, two-disk rotating membrane assembly; Development and fabrication of alternative turbulence promoter designs; Testing and evaluation of the existing and alternative turbulence promoters under selected operating conditions using a statistically designed test matrix; and Data reduction and analysis; The objective of Phase 3 research was to demonstrate the effectiveness of SpinTek's centrifugal membrane filtration as a pretreatment to remove suspended solids from a liquid waste upstream of 3M's WWL cartridge technology for the selective removal of technetium (Tc).

Daniel J. Stepan; Bradley G. Stevens; Melanie D. Hetland

1999-10-01T23:59:59.000Z

258

Adsorptive Membranes vs. Resins for Acetic Acid Removal from Biomass Hydrolysates  

SciTech Connect

Acetic acid is a compound commonly found in hemicellulosic hydrolysates. This weak acid strongly influences the bioconversion of sugar containing hydrolysates. Previous investigators have used anion exchange resins for acetic acid removal from different hemicellulosic hydrolysates. In this study, the efficiency of an anion exchange membrane was compared to that of an anion exchange resin, for acetic acid removal from a DI water solution and an acidic hemicellulose hydrolysate pretreated using two different methods. Ion exchange membranes and resins have very different geometries. Here the performance of membranes and resins is compared using two dimensionless parameters, the relative mass throughput and chromatographic bed number. The relative mass throughput arises naturally from the Thomas solution for ion exchange. The results show that the membrane exhibit better performance in terms of capacity, and loss of the desired sugars. In addition acetic acid may be eluted at a higher concentration from the membrane thus leading to the possibility of recovery and re-use of the acetic acid.

Han, B.; Carvalho, W.; Canilha, L.; da Silva, S. S.; e Silva, J. B. A.; McMillan, J. D.; Wickramasinghe, S. R.

2006-01-01T23:59:59.000Z

259

Chemical exchange program analysis.  

SciTech Connect

As part of its EMS, Sandia performs an annual environmental aspects/impacts analysis. The purpose of this analysis is to identify the environmental aspects associated with Sandia's activities, products, and services and the potential environmental impacts associated with those aspects. Division and environmental programs established objectives and targets based on the environmental aspects associated with their operations. In 2007 the most significant aspect identified was Hazardous Materials (Use and Storage). The objective for Hazardous Materials (Use and Storage) was to improve chemical handling, storage, and on-site movement of hazardous materials. One of the targets supporting this objective was to develop an effective chemical exchange program, making a business case for it in FY07, and fully implementing a comprehensive chemical exchange program in FY08. A Chemical Exchange Program (CEP) team was formed to implement this target. The team consists of representatives from the Chemical Information System (CIS), Pollution Prevention (P2), the HWMF, Procurement and the Environmental Management System (EMS). The CEP Team performed benchmarking and conducted a life-cycle analysis of the current management of chemicals at SNL/NM and compared it to Chemical Exchange alternatives. Those alternatives are as follows: (1) Revive the 'Virtual' Chemical Exchange Program; (2) Re-implement a 'Physical' Chemical Exchange Program using a Chemical Information System; and (3) Transition to a Chemical Management Services System. The analysis and benchmarking study shows that the present management of chemicals at SNL/NM is significantly disjointed and a life-cycle or 'Cradle-to-Grave' approach to chemical management is needed. This approach must consider the purchasing and maintenance costs as well as the cost of ultimate disposal of the chemicals and materials. A chemical exchange is needed as a mechanism to re-apply chemicals on site. This will not only reduce the quantity of unneeded chemicals and the amount spent on new purchases, but will also avoid disposal costs. If SNL/NM were to realize a 5 percent reduction in chemical inventory and a 10 percent reduction in disposal of unused chemicals the total savings would be $189, 200 per year.

Waffelaert, Pascale

2007-09-01T23:59:59.000Z

260

Composite metal membrane  

DOE Patents (OSTI)

A composite metal membrane including a first metal layer of Group IVB met or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof is provided together with a process for the recovery of hydrogen from a gaseous mixture including contacting a hydrogen-containing gaseous mixture with a first side of a nonporous composite metal membrane including a first metal of Group IVB metals or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof, and, separating hydrogen from a second side of the nonporous composite metal membrane.

Peachey, Nathaniel M. (Espanola, NM); Dye, Robert C. (Los Alamos, NM); Snow, Ronny C. (Los Alamos, NM); Birdsell, Stephan A. (Los Alamos, NM)

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Composite metal membrane  

DOE Patents (OSTI)

A composite metal membrane including a first metal layer of Group IVB met or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof is provided together with a process for the recovery of hydrogen from a gaseous mixture including contacting a hydrogen-containing gaseous mixture with a first side of a nonporous composite metal membrane including a first metal of Group IVB metals or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof, and, separating hydrogen from a second side of the nonporous composite metal membrane.

Peachey, N.M.; Dye, R.C.; Snow, R.C.; Birdsell, S.A.

1998-04-14T23:59:59.000Z

262

Isolation and Partial Purification of Plasma Membrane-associated Antigens from Human Osteosarcoma (TE-85) Cells in Tissue Culture  

Science Journals Connector (OSTI)

...Isolation and partial purification of plasma membrane-associated...Tumor-specific water-soluble antigens...Isolation and Partial Purification of Plasma Membrane...Tumor-specific water-soluble anti gens...could be rendered water soluble by limited...digestion and partial purification achieved by anion-exchange...

Iqbal Singh; Kwong Y. Tsang; and William S. Blakemore

1976-11-01T23:59:59.000Z

263

A membrane interferometer  

Science Journals Connector (OSTI)

...bilayer membranes from lipid monolayers. A critique . Biophys J 16 : 481 – 489 . Acknowledgments We thank Profs. Nick Melosh, Merritt Maduke, and Stephen White for useful insights and suggestions. The Cy5-DNA-lipid conjugate was synthesized...

Prasad V. Ganesan; Steven G. Boxer

2009-01-01T23:59:59.000Z

264

Wrinkling in polygonal membranes  

E-Print Network (OSTI)

boundary conditions of the polygons. When pressurised, the polygonal membranes naturally reach a parabolic shape towards their centre, the extent of which varies greatly depending on a large number of parameters, including most particularly pre...

Bonin, Arnaud Stephane

2012-02-07T23:59:59.000Z

265

Reverse Osmosis Membranes  

Science Journals Connector (OSTI)

A bibliography of citations from the U.S. National Technical Information Service data base with 183 abstracts on membranes for reverse osmosis desalination, electro-dialysis desalination and other osmotic desa...

Prof. Dr. Anthony Delyannis; Dr. Euridike-Emmy Delyannis

1980-01-01T23:59:59.000Z

266

Accurate measurement of the through-plane water content of proton-exchange  

NLE Websites -- All DOE Office Websites (Extended Search)

Accurate measurement of the through-plane water content of proton-exchange Accurate measurement of the through-plane water content of proton-exchange membranes using neutron radiography Title Accurate measurement of the through-plane water content of proton-exchange membranes using neutron radiography Publication Type Journal Article Year of Publication 2012 Authors Hussey, Daniel S., Dusan Spernjak, Adam Z. Weber, Rangachary Mukundan, Joseph Fairweather, Eric L. Brosha, John Davey, Jacob S. Spendelow, David L. Jacobson, and Rodney L. Borup Journal Journal of Applied Physics Volume 112 Issue 10 Pagination 104906 Date Published 2012 ISSN 00218979 Keywords electrolyte fuel-cells, in-situ, liquid water, microchannel plate detectors, model, nafion, polymer electrolytes, schroeders-paradox, transport, x-ray-scattering Abstract The water sorption of proton-exchange membranes (PEMs) was measured in situ using high-resolution neutron imaging in small-scale fuel cell test sections. A detailed characterization of the measurement uncertainties and corrections associated with the technique is presented. An image-processing procedure resolved a previously reported discrepancy between the measured and predicted membrane water content. With high-resolution neutron-imaging detectors, the water distributions across N1140 and N117 Nafion membranes are resolved in vapor-sorption experiments and during fuel cell and hydrogen-pump operation. The measured in situ water content of a restricted membrane at 80 degrees C is shown to agree with ex situ gravimetric measurements of free-swelling membranes over a water activity range of 0.5 to 1.0 including at liquid equilibration. Schroeder's paradox was verified by in situ water-content measurements which go from a high value at supersaturated or liquid conditions to a lower one with fully saturated vapor. At open circuit and during fuel cell operation, the measured water content indicates that the membrane is operating between the vapor-and liquid-equilibrated states.

267

Mild oxidation of tetrahydrothiophene to sulfolane over V-, Mo- and W-containing layered double hydroxides  

Science Journals Connector (OSTI)

A series of layered double hydroxides (LDH) with Mg2+ and Al3+ cations in the brucite-like layer and W-, V- and Mo-oxospecies in the interlayer gallery were prepared, characterized and tested as catalysts for the sulfolane synthesis by mild sulfoxidation of tetrahydrothiophene (THT) with H2O2. The structural and textural properties of solids and the nature of the metal species were investigated by X-ray diffraction (XRD), N2 adsorption, thermogravimetric analysis (TGA), diffuse reflectance ultraviolet spectroscopy (DRUV), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The catalytic activity was evaluated in the liquid-phase THT oxidation with dilute H2O2 in various organic solvents and temperature range of 20–30 °C. The best performances in terms of catalytic activity and stability were obtained with WO42?-containing LDH catalyst.

Alina-Livia Maciuca; Emil Dumitriu; François Fajula; Vasile Hulea

2008-01-01T23:59:59.000Z

268

Lithium-aluminum-carbonate-hydroxide hydrate coatings on aluminum alloys: Composition, structure, and processing bath chemistry  

SciTech Connect

A new corrosion resistant coating, being designed for possible replacement of chromate conversion coatings on aluminum alloys, was investigated for composition, structure, and solubility using a variety of techniques. The stoichiometry of the material, prepared by immersion of 1100 Al alloy into a lithium carbonate-lithium hydroxide solution, was approximately Li{sub 2}Al{sub 4}CO{sub 3}(OH){sub 12}{center_dot}3H{sub 2}O. Processing time was shown to be dependent upon the bath pH, and consistent coating formation required supersaturation of the coating bath with aluminum. The exact crystal structure of this hydrotalcite material, hexagonal or monoclinic, was not determined. It was shown that both the bulk material and coatings with the same nominal composition and crystal structure could be formed by precipitation from an aluminum supersatured solution of lithium carbonate. {copyright} {ital 1996 Materials Research Society.}

Drewien, C.A.; Eatough, M.O.; Tallant, D.R.; Hills, C.R.; Buchheit, R.G. [Materials and Process Sciences Center, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

1996-06-01T23:59:59.000Z

269

Hydroxide Hydrogen Bonding: Probing the Solvation Structure through Ultrafast Time Domain Raman Spectroscopy  

Science Journals Connector (OSTI)

(6-8) It has also been supported by neutron scattering experiments that suggest coordination numbers between 3.5 and 5.(9, 10) In addition, Car–Parrinello molecular dynamics (CPMD) calculations support the hypercoordination picture, suggesting a concentration and counterion-dependent distribution of 3–5 water molecules bonded to the hydroxide oxygen. ... (20, 30) The 15 fs pulses were generated by a Kerr-lens mode-locked Ti:Sapphire laser with center wavelength of 800 nm, an 80 nm bandwidth, and an 800 mW average power. ... energy structure on the potential energy surface, because the water drifts to become attached to one of the first solvation shell waters. ...

Ismael A. Heisler; Kamila Mazur; Stephen R. Meech

2011-04-27T23:59:59.000Z

270

Sorption of MS2 Bacteriophage to Layered Double Hydroxides: Effects of Reaction Time, pH, and Competing Anions  

E-Print Network (OSTI)

Sorption of MS2 Bacteriophage to Layered Double Hydroxides: Effects of Reaction Time, pBatch sorption and column breakthrough studies were conducted carbon could be used for virus removal. For example very high retention capacities for from an aqueous solution by bituminous coal (Oza and MS2. Sorption

Sparks, Donald L.

271

Chemoselective SN2? reaction of nitroalkanes to dialkyl 2-(bromomethyl)fumarates under cetyltrimethylammonium hydroxide (CTAOH) catalysis  

Science Journals Connector (OSTI)

The chemoselective SN2? reaction of a variety of primary nitroalkanes to dialkyl 2-(bromomethyl)fumarates can be efficiently performed under cetyltrimethylammonium hydroxide (CTAOH) catalysis. The ?,?-unsaturated esters were obtained in satisfactory to good yields with the complete retention of the nitro group.

Roberto Ballini; Serena Gabrielli; Alessandro Palmieri

2010-01-01T23:59:59.000Z

272

Building Energy Data Exchange Specification Scoping Report |...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Building Energy Data Exchange Specification Scoping Report Building Energy Data Exchange Specification Scoping Report The Building Energy Data Exchange Specification (BEDES),...

273

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

This is the third quarterly report on oxygen Transport Ceramic Membranes. In the following, the report describes the progress made by our university partners in Tasks 1 through 6, experimental apparatus that was designed and built for various tasks of this project, thermodynamic calculations, where applicable and work planned for the future. (Task 1) Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. (Task 2) Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. (Task 3) Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. (Task 4) Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. (Task 5) Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. (Task 6) Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2000-10-01T23:59:59.000Z

274

High Temperature Membrane Working Group  

Energy.gov (U.S. Department of Energy (DOE))

This presentation provides an overview of the High Temperature Membrane Working Group Meeting in May 2007.

275

Membrane fusion: Ready ? aim ? fire!  

Science Journals Connector (OSTI)

... All cells use a programme of membrane fusion and fission to assemble membranes, both internally and on their surface. Given that biological ... internally and on their surface. Given that biological membranes are essentially two-dimensional fluids, fusion must obey certain restrictions that prevent incompatible membranes from intermixing. Without such selective contact, ...

Randy Schekman

1998-12-10T23:59:59.000Z

276

Thermoelectric heat exchange element  

DOE Patents (OSTI)

A thermoelectric heat exchange module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.

Callas, James J. (Peoria, IL); Taher, Mahmoud A. (Peoria, IL)

2007-08-14T23:59:59.000Z

277

Trifluorostyrene containing compounds, and their use in polymer electrolyte membranes  

DOE Patents (OSTI)

A fluorinated ion exchange polymer is prepared by grafting a monomer onto a base polymer, wherein the grafting monomer is selected from the group consisting of structure 1a, 1b and mixture thereof; ##STR00001## wherein Y is selected from the group consisting of --R.sub.FSO.sub.2F, --R.sub.FSO.sub.3M, --R.sub.SO.sub.2NH.sub.2 and --R.sub.FSO.sub.2N(M)SO.sub.2R.sup.2.sub.F, where in M is hydrogen, an alkali cation or ammonium; and R.sub.F and R.sup.2.sub.F are perfluorinated or partially fluorinated, and may optionally include ether oxygens; and n is between 1 and 2 for 1a, or n is between 1 and 3 for 1b. These ion exchange polymers are useful is preparing catalyst coated membranes and membrane electrode assemblies for fuel cells.

Choudhury, Biswajit (Kingston, CA); Roelofs, Mark Gerrit (Hockessin, DE); Yang; Zhen-Yu (Hockessin, DE)

2009-07-21T23:59:59.000Z

278

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In the current research, the electrical conductivity and Seebeck coefficient were measured as a function of temperature in air. Based on these measurements, the charge carrier concentration, net acceptor dopant concentration, activation energy of conduction and mobility were estimated. The studies on the fracture toughness of the LSFT and dual phase membranes at room temperature have been completed and reported previously. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affects the mechanical properties. To study the effect of temperature on the membranes when exposed to an inert environment, the membranes (LAFT and Dual phase) were heat treated at 1000 C in air and N{sub 2} atmosphere and hardness and fracture toughness of the membranes were studied after the treatment. The indentation method was used to find the fracture toughness and the effect of the heat treatment on the mechanical properties of the membranes. Further results on the investigation of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appears to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model will serve to study ''frozen'' profiles in patterned or composite membranes.

S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-11-01T23:59:59.000Z

279

NETL: Hydrogen Selective Exfoliated Zeolite Membranes  

NLE Websites -- All DOE Office Websites (Extended Search)

Designing and Validating Ternay Pd Alloys for Optimum Sulfur/Carbon Resistance Designing and Validating Ternay Pd Alloys for Optimum Sulfur/Carbon Resistance Project No.: DE-FE0001181 Gas Permeation Cell and Test Stand Pall Corporation is developing an economically-viable hydrogen/carbon dioxide (H2/CO2) separation membrane system that would allow efficient capture of CO2 at high temperature and pressure from gasified coal in the presence of typical contaminants. Goals for the project include creating an advanced palladium alloy for optimum hydrogen separation performance using combinatorial material methods for high-throughput screening, testing, and characterization and demonstrating durability by long term testing of a pilot membrane module at a commercial coal gasification facility. The advantages of this technology are reduction of CO2 compression costs, lack of need for both upstream and downstream heat exchange and complex heat integration, and the potential for integration with water gas shift in a single compact membrane reactor system.

280

Final Report - Membranes and MEA's for Dry, Hot Operating Conditions  

SciTech Connect

The focus of this program was to develop a new Proton Exchange Membrane (PEM) which can operate under hotter, dryer conditions than the state of the art membranes today and integrate it into a Membrane Electrode Assembly (MEA). These MEA's should meet the performance and durability requirements outlined in the solicitation, operating under low humidification conditions and at temperatures ranging from -20���ºC to 120���ºC, to meet 2010 DOE technical targets for membranes. This membrane should operate under low humidification conditions and at temperatures ranging from -20���ºC to 120���ºC in order to meet DOE HFCIT 2010 commercialization targets for automotive fuel cells. Membranes developed in this program may also have improved durability and performance characteristics making them useful in stationary fuel cell applications. The new membranes, and the MEA�¢����s comprising them, should be manufacturable at high volumes and at costs which can meet industry and DOE targets. This work included: A) Studies to better understand factors controlling proton transport within the electrolyte membrane, mechanisms of polymer degradation (in situ and ex situ) and membrane durability in an MEA; B) Development of new polymers with increased proton conductivity over the range of temperatures from -20���ºC to 120���ºC and at lower levels of humidification and with improved chemical and mechanical stability; C) Development of new membrane additives for increased durability and conductivity under these dry conditions; D) Integration of these new materials into membranes and membranes into MEA�¢����s, including catalyst and gas diffusion layer selection and integration; E) Verification that these materials can be made using processes which are scalable to commercial volumes using cost effective methods; F) MEA testing in single cells using realistic automotive testing protocols. This project addresses technical barriers A (Durability) and C (Performance) from the Fuel Cells section of the 2005 Hydrogen, Fuel Cells and Infrastructure Technologies Program Multi-Year R&D Plan. In the course of this four-year program we developed a new PEM with improved proton conductivity, chemical stability and mechanical stability. We incorporated this new membrane into MEAs and evaluated performance and durability.

Hamrock, Steven J.

2011-06-30T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

In the present quarter, oxygen transport perovskite ceramic membranes are evaluated for strength and fracture in oxygen gradient conditions. Oxygen gradients are created in tubular membranes by insulating the inner surface from the reducing environment by platinum foils. Fracture in these test conditions is observed to have a gradient in trans and inter-granular fracture as opposed to pure trans-granular fracture observed in homogeneous conditions. Fracture gradients are reasoned to be due to oxygen gradient set up in the membrane, variation in stoichiometry across the thickness and due to varying decomposition of the parent perovskite. The studies are useful in predicting fracture criterion in actual reactor conditions and in understanding the initial evolution of fracture processes.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2002-07-01T23:59:59.000Z

282

Oxygen Transport Ceramic Membranes  

SciTech Connect

In this quarter a systematic analysis on the decomposition behavior of the OTM membranes at air and nitrogen were initiated to understand the structural and stoichiometric changes associated with elevated temperatures. Evaluation of the flexural strengths using 4-point bend test was also started for the dual phase membranes. Initial results on the synthesis of dual phase composite materials have been obtained. The measurements have focused on the compatibility of mixed conductors with the pure ionic conductors yttria stabilized zirconia (YSZ) and gadolinium doped ceria (GDC). The initial results obtained for three different mixed conductors suggest that (GDC) is the better choice. A new membrane permeation system has been designed and tested and sintering studies of biphasic systems are in progress.

S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2006-05-01T23:59:59.000Z

283

The many faces of ion-exchange resins  

SciTech Connect

Ion-exchange resins have been used commercially for over 60 years. Softening and demineralization of water for boiler feed and process use were then, and continue to be, the most familiar and widespread applications of ion-exchange resins throughout the chemical process industries (CPI). Several types of membrane-based technologies, such as electrodialysis, reverse osmosis and, more recently, electrodeionization are recognized as alternative methods for water treatment. Yet, modern versions of ion-exchange resins remain a major player in water treatment. In addition, these versatile materials can be found performing a wide range of tasks in both aqueous and nonaqueous environments. Some of these diverse applications include: acid or base catalysis; manufacture of high-purity solvents and reagent chemicals; separation of by-products of fermentation processes; deacidification of organic solvents; high-purity water production for semiconductor manufacture; recovery of valuable waste from dilute process effluents; controlled release of pharmaceutical products; and chromatography, both on the analytical and the industrial scale. The key to understanding the potential of ion-exchange resins is to look beyond their exchange and adsorptive characteristics, and to see their fundamental nature. In other words, it`s necessary to first consider them as spherical, particulate reactive polymers that perform chemical reactions.

McNutty, J.T. [Rohm and Haas Co., Philadelphia, PA (United States)

1997-06-01T23:59:59.000Z

284

Colloidal fouling of reverse osmosis membranes  

E-Print Network (OSTI)

the rate of fouling of reverse osmosis membranes treating32, 127-135. fouling of reverse osmosis membranes." Buros,Colloidal fouling of reverse osmosis membranes." J. Colloid

Elimelech, Menachem

1994-01-01T23:59:59.000Z

285

www.angewandte.org ACIEFS 48 (35) 63636562 (2009) ISSN 14337851 Vol. 48 No. 35  

E-Print Network (OSTI)

, Minwei Sun, Yan Liu, Gaohong He, and Yushan Yan* Hydrogen proton exchange membrane fuel cells (PEMFCs reduced, leading to high fuel cell efficiency, and catalysts in basic medium are also more durable.[3 ionomer is required to maximize the performance of hydroxide-exchange membrane fuel cells (HEMFCs

286

Heat exchanger-accumulator  

DOE Patents (OSTI)

What is disclosed is a heat exchanger-accumulator for vaporizing a refrigerant or the like, characterized by an upright pressure vessel having a top, bottom and side walls; an inlet conduit eccentrically and sealingly penetrating through the top; a tubular overflow chamber disposed within the vessel and sealingly connected with the bottom so as to define an annular outer volumetric chamber for receiving refrigerant; a heat transfer coil disposed in the outer volumetric chamber for vaporizing the liquid refrigerant that accumulates there; the heat transfer coil defining a passageway for circulating an externally supplied heat exchange fluid; transferring heat efficiently from the fluid; and freely allowing vaporized refrigerant to escape upwardly from the liquid refrigerant; and a refrigerant discharge conduit penetrating sealingly through the top and traversing substantially the length of the pressurized vessel downwardly and upwardly such that its inlet is near the top of the pressurized vessel so as to provide a means for transporting refrigerant vapor from the vessel. The refrigerant discharge conduit has metering orifices, or passageways, penetrating laterally through its walls near the bottom, communicating respectively interiorly and exteriorly of the overflow chamber for controllably carrying small amounts of liquid refrigerant and oil to the effluent stream of refrigerant gas.

Ecker, Amir L. (Dallas, TX)

1980-01-01T23:59:59.000Z

287

Lead Research and Development Activity for DOE's High Temperature, Low Relative Humidity Membrane Program (Topic 2)  

SciTech Connect

The Department of Energy’s High Temperature, Low Relative Humidity Membrane Program was begun in 2006 with the Florida Solar Energy Center (FSEC) as the lead organization. During the first three years of the program, FSEC was tasked with developing non-Nafion® proton exchange membranes with improved conductivity for fuel cells. Additionally, FSEC was responsible for developing protocols for the measurement of in-plane conductivity, providing conductivity measurements for the other funded teams, developing a method for through-plane conductivity and organizing and holding semiannual meetings of the High Temperature Membrane Working Group (HTMWG). The FSEC membrane research focused on the development of supported poly[perfluorosulfonic acid] (PFSA) – Teflon membranes and a hydrocarbon membrane, sulfonated poly(ether ether ketone). The fourth generation of the PFSA membrane (designated FSEC-4) came close to, but did not meet, the Go/No-Go milestone of 0.1 S/cm at 50% relative humidity at 120 °C. In-plane conductivity of membranes provided by the funded teams was measured and reported to the teams and DOE. Late in the third year of the program, DOE used this data and other factors to decide upon the teams to continue in the program. The teams that continued provided promising membranes to FSEC for development of membrane electrode assemblies (MEAs) that could be tested in an operating fuel cell. FSEC worked closely with each team to provide customized support. A logic flow chart was developed and discussed before MEA fabrication or any testing began. Of the five teams supported, by the end of the project, membranes from two of the teams were easily manufactured into MEAs and successfully characterized for performance. One of these teams exceeded performance targets, while the other requires further optimization. An additional team developed a membrane that shows great promise for significantly reducing membrane costs and increasing membrane lifetime.

James Fenton, PhD; Darlene Slattery, PhD; Nahid Mohajeri, PhD

2012-09-05T23:59:59.000Z

288

Ion exchange technology assessment report  

SciTech Connect

In the execution of its charter, the SRS Ion Exchange Technology Assessment Team has determined that ion exchange (IX) technology has evolved to the point where it should now be considered as a viable alternative to the SRS reference ITP/LW/PH process. The ion exchange media available today offer the ability to design ion exchange processing systems tailored to the unique physical and chemical properties of SRS soluble HLW's. The technical assessment of IX technology and its applicability to the processing of SRS soluble HLW has demonstrated that IX is unquestionably a viable technology. A task team was chartered to evaluate the technology of ion exchange and its potential for replacing the present In-Tank Precipitation and proposed Late Wash processes to remove Cs, Sr, and Pu from soluble salt solutions at the Savannah River Site. This report documents the ion exchange technology assessment and conclusions of the task team.

Duhn, E.F.

1992-01-01T23:59:59.000Z

289

Ion exchange technology assessment report  

SciTech Connect

In the execution of its charter, the SRS Ion Exchange Technology Assessment Team has determined that ion exchange (IX) technology has evolved to the point where it should now be considered as a viable alternative to the SRS reference ITP/LW/PH process. The ion exchange media available today offer the ability to design ion exchange processing systems tailored to the unique physical and chemical properties of SRS soluble HLW`s. The technical assessment of IX technology and its applicability to the processing of SRS soluble HLW has demonstrated that IX is unquestionably a viable technology. A task team was chartered to evaluate the technology of ion exchange and its potential for replacing the present In-Tank Precipitation and proposed Late Wash processes to remove Cs, Sr, and Pu from soluble salt solutions at the Savannah River Site. This report documents the ion exchange technology assessment and conclusions of the task team.

Duhn, E.F.

1992-12-31T23:59:59.000Z

290

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

This is the fifth quarterly report on a new study to develop a ceramic membrane/metal joint. Results of wetting experiments on commercially available Nickel based brazing alloys on perovskite surfaces are described. Additionally, experimental and numerical investigations on the strength of concentric ceramic/metal joints are presented.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2001-02-01T23:59:59.000Z

291

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

In the present quarter, the possibility of using a more complex interfacial engineering approach to the development of reliable and stable oxygen transport perovskite ceramic membranes/metal seals is discussed. Experiments are presented and ceramic/metal interactions are characterized. Crack growth and fracture toughness of the membrane in the reducing conditions are also discussed. Future work regarding this approach is proposed are evaluated for strength and fracture in oxygen gradient conditions. Oxygen gradients are created in tubular membranes by insulating the inner surface from the reducing environment by platinum foils. Fracture in these test conditions is observed to have a gradient in trans and inter-granular fracture as opposed to pure trans-granular fracture observed in homogeneous conditions. Fracture gradients are reasoned to be due to oxygen gradient set up in the membrane, variation in stoichiometry across the thickness and due to varying decomposition of the parent perovskite. The studies are useful in predicting fracture criterion in actual reactor conditions and in understanding the initial evolution of fracture processes.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2003-01-01T23:59:59.000Z

292

Hydrogen-Selective Membrane  

DOE Patents (OSTI)

A hydrogen-selective membrane comprises a tubular porous ceramic support having a palladium metal layer deposited on an inside surface of the ceramic support. The thickness of the palladium layer is greater than about 10 .mu.m but typically less than about 20 .mu.m. The hydrogen permeation rate of the membrane is greater than about 1.0 moles/m.sup.2.s at a temperature of greater than about 500.degree. C. and a transmembrane pressure difference of about 1,500 kPa. Moreover, the hydrogen-to-nitrogen selectivity is greater than about 600 at a temperature of greater than about 500.degree. C. and a transmembrane pressure of about 700 kPa. Hydrogen can be separated from a mixture of gases using the membrane. The method may include the step of heating the mixture of gases to a temperature of greater than about 400.degree. C. and less than about 1000.degree. C. before the step of flowing the mixture of gases past the membrane. The mixture of gases may include ammonia. The ammonia typically is decomposed to provide nitrogen and hydrogen using a catalyst such as nickel. The catalyst may be placed inside the tubular ceramic support. The mixture of gases may be supplied by an industrial process such as the mixture of exhaust gases from the IGCC process.

Collins, John P. (Boulder, CO); Way, J. Douglas (Boulder, CO)

1995-09-19T23:59:59.000Z

293

Hydrogen-selective membrane  

DOE Patents (OSTI)

A hydrogen-selective membrane comprises a tubular porous ceramic support having a palladium metal layer deposited on an inside surface of the ceramic support. The thickness of the palladium layer is greater than about 10 {micro}m but typically less than about 20 {micro}m. The hydrogen permeation rate of the membrane is greater than about 1.0 moles/m{sup 2} s at a temperature of greater than about 500 C and a transmembrane pressure difference of about 1,500 kPa. Moreover, the hydrogen-to-nitrogen selectivity is greater than about 600 at a temperature of greater than about 500 C and a transmembrane pressure of about 700 kPa. Hydrogen can be separated from a mixture of gases using the membrane. The method may include the step of heating the mixture of gases to a temperature of greater than about 400 C and less than about 1000 C before the step of flowing the mixture of gases past the membrane. The mixture of gases may include ammonia. The ammonia typically is decomposed to provide nitrogen and hydrogen using a catalyst such as nickel. The catalyst may be placed inside the tubular ceramic support. The mixture of gases may be supplied by an industrial process such as the mixture of exhaust gases from the IGCC process. 9 figs.

Collins, J.P.; Way, J.D.

1997-07-29T23:59:59.000Z

294

Hydrogen-selective membrane  

DOE Patents (OSTI)

A hydrogen-selective membrane comprises a tubular porous ceramic support having a palladium metal layer deposited on an inside surface of the ceramic support. The thickness of the palladium layer is greater than about 10 {micro}m but typically less than about 20 {micro}m. The hydrogen permeation rate of the membrane is greater than about 1.0 moles/m{sup 2}s at a temperature of greater than about 500 C and a transmembrane pressure difference of about 1,500 kPa. Moreover, the hydrogen-to-nitrogen selectivity is greater than about 600 at a temperature of greater than about 500 C and a transmembrane pressure of about 700 kPa. Hydrogen can be separated from a mixture of gases using the membrane. The method may include the step of heating the mixture of gases to a temperature of greater than about 400 C and less than about 1000 C before the step of flowing the mixture of gases past the membrane. The mixture of gases may include ammonia. The ammonia typically is decomposed to provide nitrogen and hydrogen using a catalyst such as nickel. The catalyst may be placed inside the tubular ceramic support. The mixture of gases may be supplied by an industrial process such as the mixture of exhaust gases from the IGCC process. 9 figs.

Collins, J.P.; Way, J.D.

1995-09-19T23:59:59.000Z

295

Developing a Mechanistic Understanding of Lamellar Hydroxide Mineral Carbonation Reaction Processes to Reduce CO2 Mineral Sequestration Process Cost  

NLE Websites -- All DOE Office Websites (Extended Search)

Mechanistic Understanding of Lamellar Hydroxide Mechanistic Understanding of Lamellar Hydroxide Mineral Carbonation Reaction Processes to Reduce CO 2 Mineral Sequestration Process Cost Michael J. McKelvy (mckelvy@asu.edu; 480-965-4535), Andrew V. G. Chizmeshya (chizmesh@asu.edu; 480-965-6072), Hamdallah Bearat (Hamdallah.Bearat@asu.edu; 480-965-2624), Renu Sharma (Renu.Sharma@asu.edu; 480-965-4541), and Ray W. Carpenter (carpenter@asu.edu; 480-965-4549) Center for Solid State Science and Science and Engineering of Materials PhD Program, P.O. Box 871704, Arizona State University, Tempe, Arizona 85287 USA ABSTRACT The potential environmental effects of increasing atmospheric CO 2 levels are of major worldwide concern. One alternative for managing CO 2 emissions is carbon sequestration: the capture and secure confinement of CO

296

Crystal structure of brucite-type cobalt hydroxide ?-Co{O(H,D)}2 — neutron diffraction, IR and Raman spectroscopy  

Science Journals Connector (OSTI)

The crystal structure of brucite-type Co(OD)2 (space group P3?ml, Z = 1, a = 317.79(4) pm and c = 464.2(1) pm, RI = 5.89%) has been refined by neutron powder diffraction studies on the basis of 671 observations and 44 reflections. Infrared and Raman spectra of cobalt hydroxide at different degrees of deuteration are presented and assigned to the internal, librational and translational modes. The D?O distance of 252.8 pm and the wavenumbers of the OH and OD stretching modes (3604 and 2665 cm?1, 90 K, mean values of the unit-cell group modes) do not exclude the formation of weak trifurcated hydrogen bonds. The librational and translational vibrations of Eu species are strongly coupled as shown by the respective isotopic shifts. A reassignment of the IR-allowed librations and lattice vibrations of transition metal brucite-type hydroxides is given.

Ch. Mockenhaupt; Th. Zeiske; H.D. Lutz

1998-01-01T23:59:59.000Z

297

Membrane Scientist Los Angeles, CA  

E-Print Network (OSTI)

and working hands on to ensure quality and commercial viability of reverse osmosis products including hand cast and commercial reverse osmosis membrane testing and synthesis, prototype membrane testing and new

Alpay, S. Pamir

298

Deconstruction of Lignin Model Compounds and Biomass-Derived Lignin using Layered Double Hydroxide Catalysts  

SciTech Connect

Lignin is an underutilized value stream in current biomass conversion technologies because there exist no economic and technically feasible routes for lignin depolymerization and upgrading. Base-catalyzed deconstruction (BCD) has been applied for lignin depolymerization (e.g., the Kraft process) in the pulp and paper industry for more than a century using aqueous-phase media. However, these efforts require treatment to neutralize the resulting streams, which adds significantly to the cost of lignin deconstruction. To circumvent the need for downstream treatment, here we report recent advances in the synthesis of layered double hydroxide and metal oxide catalysts to be applied to the BCD of lignin. These catalysts may prove more cost-effective than liquid-phase, non-recyclable base, and their use obviates downstream processing steps such as neutralization. Synthetic procedures for various transition-metal containing catalysts, detailed kinetics measurements using lignin model compounds, and results of the application of these catalysts to biomass-derived lignin will be presented.

Chmely, S. C.; McKinney, K. A.; Lawrence, K. R.; Sturgeon, M.; Katahira, R.; Beckham, G. T.

2013-01-01T23:59:59.000Z

299

Textural properties of synthetic nano-calcite produced by hydrothermal carbonation of calcium hydroxide  

E-Print Network (OSTI)

The hydrothermal carbonation of calcium hydroxide (Ca(OH)2) at high pressure of CO2 (initial PCO2 1/4 55 bar) and moderate to high temperature (30 and 90 1C) was used to synthesize fine particles of calcite. This method allows a high carbonation efficiency (about 95% of Ca(OH)2-CaCO3 conversion), a significant production rate (48 kg/m3 h) and high purity of product (about 96%). However, the various initial physicochemical conditions have a strong influence on the crystal size and surface area of the synthesized calcite crystals. The present study is focused on the estimation of the textural properties of synthesized calcite (morphology, specific surface area, average particle size, particle size distribution and particle size evolution with reaction time), using Rietveld refinements of X-ray diffraction (XRD) spectra, Brunauer-Emmett-Teller (BET) measurements, and scanning electron microscope (SEM) and transmission electron microscope (TEM) observations. This study demonstrate that the pressure, the temperatu...

Montes-Hernandez, German; Charlet, L; Tisserand, Delphine; Renard, F

2008-01-01T23:59:59.000Z

300

Removal of ash from Indian Assam coking coal using sodium hydroxide and acid solutions  

SciTech Connect

Mineral matter (ash) removal from Assam coking coal by leaching with different concentrations of sodium hydroxide and acid (HCl, H{sub 2}SO{sub 4}, HNO{sub 3}, and HF) solutions has been investigated at a temperature of 75 C. The parameters tested were concentration of NaOH, type of acid, concentration of acids, and number of acid leaching steps. Total ash removed increased with increase of NaOH and acid concentrations up to the range studied. For the same experimental conditions, treatment of caustic leached coal in HCl acid resulted in better demineralization than in H{sub 2}SO{sub 4} or HNO{sub 3} acid. In the NaOH-HNO{sub 3} leaching method, a higher concentration (>20%) of HNO{sub 3} acid had an adverse effect on the de-ashing of coal. The NaOH-HF leaching process has been found to be the most effective method of coal de-ashing. The two acid treatment steps (HCl-H{sub 2}SO{sub 4}/HCl-HNO{sub 3}) after caustic leaching are the next most effective methods of coal de-ashing. The removal of mineral matter (including S) from coal is expected to decrease the graphite reactivity and thus the atmospheric pollution (due to the generation of smaller quantities of CO and SO{sub 2} gases).

Kumar, M.; Shankar, R.H.

2000-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

basic exchange telecommunications radio service  

Science Journals Connector (OSTI)

A service that extends telecommunications service to rural, outlying, and remote...Common abbreviation BETRS. Note: In the basic exchange telecommunications radio service (BETRS), the (a)....

2001-01-01T23:59:59.000Z

302

Ion Recognition Approach to Volume Reduction of Alkaline Tank Waste by Separation and Recycle of Sodium Hydroxide and Sodium Nitrate  

SciTech Connect

Disposal of high-level nuclear waste is horrendously expensive, in large part because the actual radioactive matter in the tanks has been diluted over 1000-fold by ordinary inorganic chemicals. Treatment processes themselves can exacerbate the problem by adding further volume to the waste. Waste retrieval and sludge washing, for example, will require copious amounts of sodium hydroxide. If the needed sodium hydroxide could be separated from the waste and recycled, however, the addition of fresh sodium hydroxide could be avoided, ultimately reducing the final waste volume and associated disposal costs. The major objective of this research is to explore new liquid-liquid extraction approaches to the selective separation of sodium hydroxide from alkaline high-level wastes stored in underground tanks at the Hanford and Savannah River sites. Consideration is also given to separating potassium and abundant anions, including nitrate, nitrite, aluminate, and carbonate. Salts of these ions represent possible additional value for recycle, alternative disposal, or even use as commodity chemicals. A comprehensive approach toward understanding the extractive chemistry of these salts is envisioned, involving systems of varying complexity, from use of simple solvents to new bifunctional host molecules for ion-pair recognition. These extractants will ideally require no adjustment of the waste composition and will release the extracted salt into water, thereby consuming no additional chemicals and producing no additional waste volume. The overall goal of this research is to provide a scientific foundation upon which the feasibility of new liquid-liquid extraction chemistry applicable to the bulk reduction of the volume of tank waste can be evaluated.

Moyer, Bruce A.; Marchand, Alan P.

2001-06-01T23:59:59.000Z

303

Ion Recognition Approach to Volume Reduction of Alkaline Tank Waste by Separation and Recycle of Sodium Hydroxide and Sodium Nitrate  

SciTech Connect

Disposal of high- level waste is horrendously expensive, in large part because the actual radioactive matter in the tanks has been diluted over 1000-fold by ordinary inorganic chemicals. Treatment processes themselves can exacerbate the problem by adding further volume to the waste. Waste retrieval and sludge washing, for example, will require copious amounts of sodium hydroxide. If the needed sodium hydroxide could be separated from the waste and recycled, however, the addition of fresh sodium hydroxide could be avoided, ultimately reducing the final waste volume and associated disposal costs. The major objective of this research is to explore new liquid- liquid extraction approaches to the selective separation of sodium hydroxide from alkaline high-level wastes stored in underground tanks at the Hanford and Savannah River sites. Consideration is also given to separating potassium and abundant anions, including nitrate, nitrite, aluminate, and carbonate. Salts of these ions represent possible additional value for recycle, alternative disposal, or even use as commodity chemicals. A comprehensive approach toward understanding the extractive chemistry of these salts is envisioned, involving systems of varying complexity, from use of simple solvents to new bifunctional host molecules for ion-pair recognition. These extractants will ideally require no adjustment of the waste composition and will release the extracted salt into water, thereby consuming no additional chemicals and producing no additional waste volume. The overall goal of this research is to provide a scientific foundation upon which the feasibility of new liquid-liquid extraction chemistry applicable to the bulk reduction of the volume of tank waste can be evaluated.

Moyer, Bruce A.; Marchand, Alan P.

2000-06-01T23:59:59.000Z

304

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

Conversion of natural gas to liquid fuels and chemicals is a major goal for the Nation as it enters the 21st Century. Technically robust and economically viable processes are needed to capture the value of the vast reserves of natural gas on Alaska's North Slope, and wean the Nation from dependence on foreign petroleum sources. Technologies that are emerging to fulfill this need are all based syngas as an intermediate. Syngas (a mixture of hydrogen and carbon monoxide) is a fundamental building block from which chemicals and fuels can be derived. Lower cost syngas translates directly into more cost-competitive fuels and chemicals. The currently practiced commercial technology for making syngas is either steam methane reforming (SMR) or a two-step process involving cryogenic oxygen separation followed by natural gas partial oxidation (POX). These high-energy, capital-intensive processes do not always produce syngas at a cost that makes its derivatives competitive with current petroleum-based fuels and chemicals. This project has the following 6 main tasks: Task 1--Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. Task 2--Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. Task 3--Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. Task 4--Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. Task 5--Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. Task 6--Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2001-12-01T23:59:59.000Z

305

PII S0016-7037(98)00136-7 The kinetics of mixed Ni-Al hydroxide formation on clay and aluminum oxide minerals  

E-Print Network (OSTI)

PII S0016-7037(98)00136-7 The kinetics of mixed Ni-Al hydroxide formation on clay and aluminum. This finding indicates that the dissolution of clay and aluminum oxide minerals can be promoted by metal ions

Sparks, Donald L.

306

Ni Sorption on Pyrophyllite: Evidence for the Formation of Ni-Al Hydroxide and Its Transformation into Ni-Silicate by Visible,  

E-Print Network (OSTI)

Ni Sorption on Pyrophyllite: Evidence for the Formation of Ni-Al Hydroxide and Its Transformation. Ford, K. S. Scheckel Former EXAFS studies of the sorption of Co and Ni on Al-containing clay minerals

Sparks, Donald L.

307

Automotive Perspective on Membrane Evaluation  

Energy.gov (U.S. Department of Energy (DOE))

Presentation at the 2008 High Temperature Membrane Working Group Meeting held June 9, 2008, in Washington, DC

308

Reactive Membrane Barriers for Containment of Subsurface Contamination  

SciTech Connect

The overall goal of this project was to develop reactive membrane barriers--a new and flexible technique to contain and stabilize subsurface contaminants. Polymer membranes will leak once a contaminant is able to diffuse through the membrane. By incorporating a reactive material in the polymer, however, the contaminant is degraded or immobilized within the membrane. These processes increase the time for contaminants to breakthrough the barrier (i.e. the lag time) and can dramatically extend barrier lifetimes. In this work, reactive barrier membranes containing zero-valent iron (Fe{sup 0}) or crystalline silicotitanate (CST) were developed to prevent the migration of chlorinated solvents and cesium-137, respectively. These studies were complemented by the development of models quantifying the leakage/kill time of reactive membranes and describing the behavior of products produced via the reactions within the membranes. First, poly(vinyl alcohol) (PVA) membranes containing Fe{sup 0} and CST were prepared and tested. Although PVA is not useful in practical applications, it allows experiments to be performed rapidly and the results to be compared to theory. For copper ions (Cu{sup 2+}) and carbon tetrachloride, the barrier was effective, increasing the time to breakthrough over 300 times. Even better performance was expected, and the percentage of the iron used in the reaction with the contaminants was determined. For cesium, the CST laden membranes increased lag times more than 30 times, and performed better than theoretical predictions. A modified theory was developed for ion exchangers in reactive membranes to explain this result. With the PVA membranes, the effect of a groundwater matrix on barrier performance was tested. Using Hanford groundwater, the performance of Fe{sup 0} barriers decreased compared to solutions containing a pH buffer and high levels of chloride (both of which promote iron reactivity). For the CST bearing membrane, performance improved by a factor of three when groundwater was used in place of deionized water. The performance of high density polyethylene (HDPE) membranes containing Fe{sup 0} was then evaluating using carbon tetrachloride as the target contaminant. Only with a hydrophilic additive (glycerol), was the iron able to extend lag times. Lag times were increased by a factor of 15, but only 2-3% of the iron was used, likely due to formation of oxide precipitates on the iron surface, which slowed the reaction. With thicker membranes and lower carbon tetrachloride concentrations, it is expected that performance will improve. Previous models for reactive membranes were also extended. The lag time is a measurement of when the barrier is breached, but contaminants do slowly leak through prior to the lag time. Thus, two parameters, the leakage and the kill time, were developed to determine when a certain amount of pollutant has escaped (the kill time) or when a given exposure (concentration x time) occurs (the leakage). Finally, a model was developed to explain the behavior of mobile reaction products in reactive barrier membranes. Although the goal of the technology is to avoid such products, it is important to be able to predict how these products will behave. Interestingly, calculations show that for any mobile reaction products, one half of the mass will diffuse into the containment area and one half will escape, assuming that the volumes of the containment area and the surrounding environment are much larger than the barrier membrane. These parameters/models will aid in the effective design of barrier membranes.

William A. Arnold; Edward L. Cussler

2007-02-26T23:59:59.000Z

309

Robust Polymer Composite Membranes for Hydrogen Separation |...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Robust Polymer Composite Membranes for Hydrogen Separation Robust Polymer Composite Membranes for Hydrogen Separation polymercompositemembranes.pdf More Documents & Publications...

310

Active oxygen species and mechanism for low-temperature CO oxidation reaction on a TiO{sub 2}-supported Au catalyst prepared from Au(PPh{sub 3})(NO{sub 3}) and as-precipitated titanium hydroxide  

SciTech Connect

The active oxygen species and mechanism for catalytic CO oxidation with O{sub 2} on a highly active TiO{sub 2}-supported Au catalyst (denoted as Au/Ti(OH){sub 4}{sup *}), which was prepared by supporting a Au-phophine complex on as-precipitated wet titanium hydroxide followed by calcination at 673 K, have been studied by means of oxygen isotope exchange, O{sub 2} temperature-programmed desorption (O{sub 2} TPD), electron spin resonance (ESR), and Fourier-transformed infrared spectroscopy (FT-IR). Surface lattice oxygen atoms on the Au/Ti(OH){sub 4}{sup *} catalyst were inactive for oxygen exchange with O{sub 2} and CO and also for CO oxidation at room temperature. The surface lattice oxygen atoms were exchanged only with the oxygen atoms of CO{sub 2}, probably via carbonates. O{sub 2} did not dissociate to atomic oxygen on the catalyst. The catalyst showed a paramagnetic signal at g = 2.002 due to unpaired electrons trapped at oxygen vacancies mainly at the surface. O{sub 2} adsorbed on the oxygen vacancies to form superoxide O{sub 2}{sup {minus}} with g{sub 1} = 2.020, g{sub 2} = 2.010, and g{sub 3} = 2.005, which are characteristic of O{sub 2}{sup {minus}} with an angular arrangement. Upon CO exposure, all the adsorbed oxygen species disappeared. The mechanism for the catalytic CO oxidation on the active Au/Ti(OH){sub 4}{sup *} catalyst is discussed in detail and compared with mechanisms reported previously.

Liu, H.; Kozlov, A.I.; Kozlova, A.P.; Shido, Takafumi; Asakura, Kiyotaka; Iwasawa, Yasuhiro [Univ. of Tokyo (Japan)] [Univ. of Tokyo (Japan)

1999-07-25T23:59:59.000Z

311

Interaction of D2O with a Thick BaO Film: Formation of and Phase Transitions in Barium Hydroxides  

SciTech Connect

The interaction of D2O with a thick BaO film (? 20 mono-layer equivalent (MLE)) on ultra-thin Al2O3/NiAl(110) was investigated with temperature programmed desorption (TPD) and infrared reflection absorption spectroscopy (IRAS). Upon D2O exposure of a thick BaO film amorphous barium hydroxide formed at room temperature that readily converted to crystalline Ba(OD)2 phases during annealing in ultra-high vacuum (UHV). The formation of crystalline hydroxide phases depends on the initial D2O exposure at 300 K. Following low D2O exposure at room temperature that results in the formation of amorphous barium hydroxide with no hydrating water, only the a-Ba(OD)2 phase was observed after 400 K annealing. The sample that was exposed to D2O extensively (i.e. hydrated amorphous barium hydroxide formed) showed a series of phase transformations as the sample was annealed to increasingly higher temperatures: amorphous- Ba(OD)2•xD2O (x>1)à b-Ba(OD)2.D2Oà b-Ba(OD)2àa-Ba(OD)2. The results of TPD experiments completely agreed with this phase transformation scheme: hydrating water molecules desorbed first at 425 K, allowing the formation of the b-Ba(OD)2.D2O phase. Desorption of water from b-Ba(OD)2.D2O at around 475 K leads to the formation of b-Ba(OD)2 and its subsequent conversion to a-Ba(OH)2. All the barium hydroxides thermally decomposed at T < 550 K. When the BaO film was exposed to D2O at 425 K crystalline b-Ba(OD)2 formed initially, which lead to the formation of a small amount of a-Ba(OD)2 as well at low D2O exposures. At high D2O exposures the dominant phase was b-Ba(OD)2.xD2O, and no a-phase was seen.

Yi, Cheol-Woo; Szanyi, Janos

2009-09-03T23:59:59.000Z

312

Neutron-Proton Exchange Demonstrated  

Science Journals Connector (OSTI)

Neutron-Proton Exchange Demonstrated ... EVIDENCE of the exchange of charge between protons and neutrons has recently been obtained from studies in the high power cyclotron, according to Ernest O. Lawrence, professor of physics at the University of California a* Berkeley. ...

1947-11-03T23:59:59.000Z

313

Technology Performance Exchange (Fact Sheet)  

SciTech Connect

This fact sheet, 'The Technology Performance Exchange' will be presented at the ET Summit, held at the Pasadena Convention Center on October 15-17, 2012. The Technology Performance Exchange will be a centralized, Web-based portal for finding and sharing energy performance data for commercial building technologies.

Not Available

2012-10-01T23:59:59.000Z

314

Gas Exchange, Partial Pressure Gradients,  

E-Print Network (OSTI)

Gas Exchange, Partial Pressure Gradients, and the Oxygen Window Johnny E. Brian, Jr., M of circulatory and gas transport physiology, and the best place to start is with normobaric physiology. LIFE affect the precise gas exchange occurring in individual areas of the lungs and body tissues. To make

Riba Sagarra, Jaume

315

Waste treatment by reverse osmosis and membrane processes. January 1980-January 1992 (Citations from the NTIS Data Base). Rept. for Jan 80-Jan 92  

SciTech Connect

The bibliography contains citations concerning the use of membranes and reverse osmosis to treat wastes. Ion exchange, electrodialysis, and ultrafiltration processes are described. Removal of metals, sodium compounds, nitrates, fluorides, dyes, and radioactive waste using membranes is examined. Wastewater treatment for chemical, pulp, textile, and steel mills using this technology is included. (Contains 63 citations with title list and subject index.)

Not Available

1991-12-01T23:59:59.000Z

316

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. Thermogravimetric analysis (TGA) was carried out on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} to investigate oxygen deficiency ({delta}) of the sample. The TGA was performed in a controlled atmosphere using oxygen, argon, carbon monoxide and carbon dioxide with adjustable gas flow rates. In this experiment, the weight loss and gain of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} was directly measured by TGA. The weight change of the sample was evaluated at between 600 and 1250 C in air or 1000 C as a function of oxygen partial pressure. The oxygen deficiencies calculated from TGA data as a function of oxygen activity and temperature will be estimated and compared with that from neutron diffraction measurement in air. The LSFT and LSFT/CGO membranes were fabricated from the powder obtained from Praxair Specialty Ceramics. The sintered membranes were subjected to microstructure analysis and hardness analysis. The LSFT membrane is composed of fine grains with two kinds of grain morphology. The grain size distribution was characterized using image analysis. In LSFT/CGO membrane a lot of grain pullout was observed from the less dense, porous phase. The hardness of the LSFT and dual phase membranes were studied at various loads. The hardness values obtained from the cross section of the membranes were also compared to that of the values obtained from the surface. An electrochemical cell has been designed and built for measurements of the Seebeck coefficient as a function of temperature and pressure. Measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} as a function of temperature an oxygen partial pressure are reported. Further analysis of the dilatometry data obtained previously is presented. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

S. Bandopadhyay; N. Nagabhushana; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-02-01T23:59:59.000Z

317

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

In the present quarter, experiments are presented on ceramic/metal interactions of Zirconia/Ni-B-Si system and with a thin Ti coating deposited on zirconia surface. Processing of perovskites of LSC, LSF and LSCF composition for evaluation of mechanical properties as a function of environment are begun. The studies are to be in parallel with LSFCO composition to characterize the segregation of cations and slow crack growth in environmental conditions. La{sub 1-x}Sr{sub x}FeO{sub 3-d} has also been characterized for paramagnetic ordering at room temperature and the evolution of magnetic moments as a function of temperature are investigated. Investigation on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane transport.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2003-01-01T23:59:59.000Z

318

Solid-state membrane module  

DOE Patents (OSTI)

Solid-state membrane modules comprising at least one membrane unit, where the membrane unit has a dense mixed conducting oxide layer, and at least one conduit or manifold wherein the conduit or manifold comprises a dense layer and at least one of a porous layer and a slotted layer contiguous with the dense layer. The solid-state membrane modules may be used to carry out a variety of processes including the separating of any ionizable component from a feedstream wherein such ionizable component is capable of being transported through a dense mixed conducting oxide layer of the membrane units making up the membrane modules. For ease of construction, the membrane units may be planar.

Gordon, John Howard (Salt Lake City, UT); Taylor, Dale M. (Murray, UT)

2011-06-07T23:59:59.000Z

319

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

This is the fourth quarterly report on a new study to develop a ceramic membrane/metal joint. The first experiments using the La-Sr-Fe-O ceramic are reported. Some of the analysis performed on the samples obtained are commented upon. A set of experiments to characterize the mechanical strength and thermal fatigue properties of the joints has been designed and begun. Finite element models of joints used to model residual stresses are described.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2000-07-01T23:59:59.000Z

320

Computational and experimental study of nanoporous membranes for water desalination and decontamination.  

SciTech Connect

Fundamentals of ion transport in nanopores were studied through a joint experimental and computational effort. The study evaluated both nanoporous polymer membranes and track-etched nanoporous polycarbonate membranes. The track-etched membranes provide a geometrically well characterized platform, while the polymer membranes are more closely related to ion exchange systems currently deployed in RO and ED applications. The experimental effort explored transport properties of the different membrane materials. Poly(aniline) membranes showed that flux could be controlled by templating with molecules of defined size. Track-etched polycarbonate membranes were modified using oxygen plasma treatments, UV-ozone exposure, and UV-ozone with thermal grafting, providing an avenue to functionalized membranes, increased wettability, and improved surface characteristic lifetimes. The modeling effort resulted in a novel multiphysics multiscale simulation model for field-driven transport in nanopores. This model was applied to a parametric study of the effects of pore charge and field strength on ion transport and charge exclusion in a nanopore representative of a track-etched polycarbonate membrane. The goal of this research was to uncover the factors that control the flux of ions through a nanoporous material and to develop tools and capabilities for further studies. Continuation studies will build toward more specific applications, such as polymers with attached sulfonate groups, and complex modeling methods and geometries.

Hickner, Michael A. (Penn State University, University Park, PA); Chinn, Douglas Alan (Sandia National Laboratories, Albuquerque, NM); Adalsteinsson, Helgi; Long, Kevin R. (Texas Tech University, Lubbock, TX); Kent, Michael Stuart (Sandia National Laboratories, Albuquerque, NM); Debusschere, Bert J.; Zendejas, Frank J.; Tran, Huu M.; Najm, Habib N.; Simmons, Blake Alexander

2008-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Air bubble-initiated biofabrication of freestanding, semi-permeable biopolymer membranes in PDMS microfluidics  

Science Journals Connector (OSTI)

Abstract Membrane functionality in microfluidics is critical for sample separation, concentration, compartmentalization, filtration, pumping, gradient generation, gas–liquid exchange, and other processes. Integration of functional membranes in microfluidics, however, is nontrivial. Here, we report a simple approach for biofabricating freestanding, semi-permeable biopolymer membranes in microfluidics, initiated with intentionally trapped air bubbles caught within specifically designed polydimethylsiloxane (PDMS) apertures. Pressure-driven dissipation of air bubbles through the gas permeable PDMS facilitates local and quiescent contact of two oppositely charged polyelectrolyte polysaccharides forming a layered or sandwiched membrane. This polyelectrolyte complex membrane (PECM) is permeable to ions including hydroxyl ions, which further facilitates layer-by-layer assembly of membrane stratum. Assembled membranes that bridge the 40-?m apertures are sufficiently strong to withstand >1 atmosphere hydrostatic pressure. Further, the semi-permeable membranes allow for programmed generation of small molecule gradients while preventing protein efflux. We envision the simplicity of fabrication, which requires no reagents or complicated valving, when coupled with the functional properties of the membrane polysaccharides, will find utility in cell and tissue studies including preclinical drug screening and toxicity analyses.

Xiaolong Luo; Hsuan-Chen Wu; Jordan Betz; Gary W. Rubloff; William E. Bentley

2014-01-01T23:59:59.000Z

322

Novel Catalytic Membrane Reactors  

SciTech Connect

There are many industrial catalytic organic reversible reactions with amines or alcohols that have water as one of the products. Many of these reactions are homogeneously catalyzed. In all cases removal of water facilitates the reaction and produces more of the desired chemical product. By shifting the reaction to right we produce more chemical product with little or no additional capital investment. Many of these reactions can also relate to bioprocesses. Given the large number of water-organic compound separations achievable and the ability of the Compact Membrane Systems, Inc. (CMS) perfluoro membranes to withstand these harsh operating conditions, this is an ideal demonstration system for the water-of-reaction removal using a membrane reactor. Enhanced reaction synthesis is consistent with the DOE objective to lower the energy intensity of U.S. industry 25% by 2017 in accord with the Energy Policy Act of 2005 and to improve the United States manufacturing competitiveness. The objective of this program is to develop the platform technology for enhancing homogeneous catalytic chemical syntheses.

Stuart Nemser, PhD

2010-10-01T23:59:59.000Z

323

SingleSep Disposable Capsules A Separation Technology Based on Microporous Membranes  

E-Print Network (OSTI)

Sartobind SingleSep Disposable Capsules A Separation Technology Based on Microporous Membranes into a conventional housing for easy and quick handling, making ion exchange purification nearly as easy as filtration procedures. For upscaling to production and downstream pro- cessing, Sartorius offers Sartobind Multi

Lebendiker, Mario

324

Regeneration of strong-base anion-exchange resins by sequential chemical displacement  

DOE Patents (OSTI)

A method for regenerating strong-base anion exchange resins utilizing a sequential chemical displacement technique with new regenerant formulation. The new first regenerant solution is composed of a mixture of ferric chloride, a water-miscible organic solvent, hydrochloric acid, and water in which tetrachloroferrate anion is formed and used to displace the target anions on the resin. The second regenerant is composed of a dilute hydrochloric acid and is used to decompose tetrachloroferrate and elute ferric ions, thereby regenerating the resin. Alternative chemical displacement methods include: (1) displacement of target anions with fluoroborate followed by nitrate or salicylate and (2) displacement of target anions with salicylate followed by dilute hydrochloric acid. The methodology offers an improved regeneration efficiency, recovery, and waste minimization over the conventional displacement technique using sodium chloride (or a brine) or alkali metal hydroxide.

Brown, Gilbert M. (Knoxville, TN); Gu, Baohua (Oak Ridge, TN); Moyer, Bruce A. (Oak Ridge, TN); Bonnesen, Peter V. (Knoxville, TN)

2002-01-01T23:59:59.000Z

325

CX-000598: Categorical Exclusion Determination | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

598: Categorical Exclusion Determination 598: Categorical Exclusion Determination CX-000598: Categorical Exclusion Determination 25A5311 - Quaternary Phosphonium Based Hydroxide Exchange Membranes CX(s) Applied: B3.6 Date: 12/15/2009 Location(s): California Office(s): Advanced Research Projects Agency - Energy The technical objective of this project is to develop and master a series of technologies to prepare/produce the commercialization-ready high-performance quarternary phosphorium (QP)-based hydroxide exchange membranes (HEMs) that have high hydroxide conductivity, outstanding alkaline-stability, suitable dimension-stability, and high hydroxide exchange membrane fuel cell (HEMFC) performance. This project will help the United States maintain, unquestionably, the technological lead in developing and deploying advanced energy technologies. If successful, the

326

Modular heat exchanger  

DOE Patents (OSTI)

A shell and tube heat exchanger having a plurality of individually removable tube bundle modules. A lattice of structural steel forming rectangular openings therein is placed at each end of a cylindrical shell. Longitudinal structural members are placed in the shell between corners of the rectangular openings situated on opposite ends of the shell. Intermediate support members interconnect the longitudinal supports so as to increase the longitudinal supports rigidity. Rectangular parallelpiped tube bundle moldules occupy the space defined by the longitudinal supports and end supports and each include a rectangular tube sheet situated on each end of a plurality of tubes extending therethrough, a plurality of rectangular tube supports located between the tube sheets, and a tube bundle module stiffening structure disposed about the bundle's periphery and being attached to the tube sheets and tube supports. The corners of each tube bundle module have longitudinal framework members which are mateable with and supported by the longitudinal support members. Intermediate support members constitute several lattice, each of which is situate d in a plane between the end support members. The intermediate support members constituting the several lattice extend horizontally and vertically between longitudinal supports of adjacent tube module voids. An alternative embodiment for intermediate support members constitute a series of structural plates situated at the corners of the module voids and having recesses therein for receiving the respective longitudinal support members adjacent thereto, protrusions separating the recesses, and a plurality of struts situated between protrusions of adjacent structural plates.

Giardina, Angelo R. [Marple Township, Delaware County, PA

1981-03-03T23:59:59.000Z

327

Membranes, methods of making membranes, and methods of separating gases using membranes  

DOE Patents (OSTI)

Membranes, methods of making membranes, and methods of separating gases using membranes are provided. The membranes can include at least one hydrophilic polymer, at least one cross-linking agent, at least one base, and at least one amino compound. The methods of separating gases using membranes can include contacting a gas stream containing at least one of CO.sub.2, H.sub.2S, and HCl with one side of a nonporous and at least one of CO.sub.2, H.sub.2S, and HCl selectively permeable membrane such that at least one of CO.sub.2, H.sub.2S, and HCl is selectively transported through the membrane.

Ho, W. S. Winston

2012-10-02T23:59:59.000Z

328

Worldwide 'Power exchanges' | OpenEI Community  

Open Energy Info (EERE)

Indian government is attempting to set-up power exchang, where one can buysell electrical power (just like stock exchange). Please let me know: If power exchange exists in...

329

Heat exchanger with ceramic elements  

DOE Patents (OSTI)

An annular heat exchanger assembly includes a plurality of low thermal growth ceramic heat exchange members with inlet and exit flow ports on distinct faces. A mounting member locates each ceramic member in a near-annular array and seals the flow ports on the distinct faces into the separate flow paths of the heat exchanger. The mounting member adjusts for the temperature gradient in the assembly and the different coefficients of thermal expansion of the members of the assembly during all operating temperatures.

Corey, John A. (North Troy, NY)

1986-01-01T23:59:59.000Z

330

EVALUATION OF PROTON-CONDUCTING MEMBRANES FOR USE IN A SULFUR-DIOXIDE DEPOLARIZED ELECTROLYZER  

SciTech Connect

The chemical stability, sulfur dioxide transport, ionic conductivity, and electrolyzer performance have been measured for several commercially available and experimental proton exchange membranes (PEMs) for use in a sulfur dioxide depolarized electrolyzer (SDE). The SDE's function is to produce hydrogen by using the Hybrid Sulfur (HyS) Process, a sulfur based electrochemical/thermochemical hybrid cycle. Membrane stability was evaluated using a screening process where each candidate PEM was heated at 80 C in 60 wt. % H{sub 2}SO{sub 4} for 24 hours. Following acid exposure, chemical stability for each membrane was evaluated by FTIR using the ATR sampling technique. Membrane SO{sub 2} transport was evaluated using a two-chamber permeation cell. SO{sub 2} was introduced into one chamber whereupon SO{sub 2} transported across the membrane into the other chamber and oxidized to H{sub 2}SO{sub 4} at an anode positioned immediately adjacent to the membrane. The resulting current was used to determine the SO{sub 2} flux and SO{sub 2} transport. Additionally, membrane electrode assemblies (MEAs) were prepared from candidate membranes to evaluate ionic conductivity and selectivity (ionic conductivity vs. SO{sub 2} transport) which can serve as a tool for selecting membranes. MEAs were also performance tested in a HyS electrolyzer measuring current density versus a constant cell voltage (1V, 80 C in SO{sub 2} saturated 30 wt% H2SO{sub 4}). Finally, candidate membranes were evaluated considering all measured parameters including SO{sub 2} flux, SO{sub 2} transport, ionic conductivity, HyS electrolyzer performance, and membrane stability. Candidate membranes included both PFSA and non-PFSA polymers and polymer blends of which the non-PFSA polymers, BPVE-6F and PBI, showed the best selectivity.

Hobbs, D.; Elvington, M.; Colon-Mercado, H.

2009-11-11T23:59:59.000Z

331

Durable, Low-cost, Improved Fuel Cell Membranes  

SciTech Connect

The development of low cost, durable membranes and membranes electrode assemblies (MEAs) that operate under reduced relative humidity (RH) conditions remain a critical challenge for the successful introduction of fuel cells into mass markets. It was the goal of the team lead by Arkema, Inc. to address these shortages. Thus, this project addresses the following technical barriers from the fuel cells section of the Hydrogen Fuel Cells and Infrastructure Technologies Program Multi-Year Research, Development and Demonstration Plan: (A) Durability (B) Cost Arkema’s approach consisted of using blends of polyvinylidenefluoride (PVDF) and proprietary sulfonated polyelectrolytes. In the traditional approach to polyelectrolytes for proton exchange membranes (PEM), all the required properties are “packaged” in one macromolecule. The properties of interest include proton conductivity, mechanical properties, durability, and water/gas transport. This is the case, for example, for perfluorosulfonic acid-containing (PFSA) membranes. However, the cost of these materials is high, largely due to the complexity and the number of steps involved in their synthesis. In addition, they suffer other shortcomings such as mediocre mechanical properties and insufficient durability for some applications. The strength and originality of Arkema’s approach lies in the decoupling of ion conductivity from the other requirements. Kynar® PVDF provides an exceptional combination of properties that make it ideally suited for a membrane matrix (Kynar® is a registered trademark of Arkema Inc.). It exhibits outstanding chemical resistance in highly oxidative and acidic environments. In work with a prior grant, a membrane known as M41 was developed by Arkema. M41 had many of the properties needed for a high performance PEM, but had a significant deficiency in conductivity at low RH. In the first phase of this work, the processing parameters of M41 were explored as a means to increase its proton conductivity. Optimizing the processing of M41 was found to increase its proton conductivity by almost an order of magnitude at 50% RH. Characterization of the membrane morphology with Karren More at Oak Ridge National Laboratory showed that the membrane morphology was complex. This technology platform was dubbed M43 and was used as a baseline in the majority of the work on the project. Although its performance was superior to M41, M43 still showed proton conductivity an order of magnitude lower than that of a PFSA membrane at 50% RH. The MEA performance of M43 could be increased by reducing the thickness from 1 to 0.6 mils. However, the performance of the thinner M43 still did not match that of a PFSA membrane.

Chris Roger; David Mountz; Wensheng He; Tao Zhang

2011-03-17T23:59:59.000Z

332

Energy Efficiency Exchange 2015 | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Energy Efficiency Exchange 2015 Energy Efficiency Exchange 2015 As the nation's largest energy consumer, the federal government has a tremendous opportunity and clear...

333

Materials - Micro heat exchangers ... | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

Materials - Micro heat exchangers ... Heat exchanger components fabricated with 3-D printing and analyzed with neutron imaging create a world of opportunities for electronic...

334

Integrated Module Heat Exchanger | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Module Heat Exchanger Integrated Module Heat Exchanger 2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting...

335

Better Buildings Residential Network Orientation Peer Exchange...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Better Buildings Residential Network Orientation Peer Exchange Webinar Better Buildings Residential Network Orientation Peer Exchange Webinar September 11, 2014 7:00PM to 8:3...

336

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In the previous research, the reference point of oxygen occupancy was determined and verified. In the current research, the oxygen occupancy was investigated at 1200 C as a function of oxygen activity and compared with that at 1000 C. The cause of bumps at about 200 C was also investigated by using different heating and cooling rates during TGA. The fracture toughness of LSFT and dual phase membranes at room temperature is an important mechanical property. Vicker's indentation method was used to evaluate this toughness. Through this technique, a K{sub Ic} (Mode-I Fracture Toughness) value is attained by means of semi-empirical correlations between the indentation load and the length of the cracks emanating from the corresponding Vickers indentation impression. In the present investigation, crack propagation behavior was extensively analyzed in order to understand the strengthening mechanisms involved in the non-transforming La based ceramic composites. Cracks were generated using Vicker's indenter and used to identify and evaluate the toughening mechanisms involved. Preliminary results of an electron microscopy study of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appear to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. Modeling of the isotopic transients on operating membranes (LSCrF-2828 at 900 C) and a ''frozen'' isotope profile have been analyzed in conjunction with a 1-D model to reveal the gradient in oxygen diffusivity through the membrane under conditions of high chemical gradients.

S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-08-01T23:59:59.000Z

337

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. The in situ electrical conductivity and Seebeck coefficient measurements were made on LSFT at 1000 and 1200 C over the oxygen activity range from air to 10{sup -15} atm. The electrical conductivity measurements exhibited a p to n type transition at an oxygen activity of 1 x 10{sup -10} at 1000 C and 1 x 10{sup -6} at 1200 C. Thermogravimetric studies were also carried out over the same oxygen activities and temperatures. Based on the results of these measurements, the chemical and mechanical stability range of LSFT were determined and defect structure was established. The studies on the fracture toughness of the LSFT and dual phase membranes exposed to air and N{sub 2} at 1000 C was done and the XRD and SEM analysis of the specimens were carried out to understand the structural and microstructural changes. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affect the mechanical properties. A complete transformation of fracture behavior was observed in the N{sub 2} treated LSFT samples. Further results to investigate the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appear to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. Recent results on transient kinetic data are presented. The 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model is used to study ''frozen'' profiles in patterned or composite membranes.

S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-02-01T23:59:59.000Z

338

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the initial studies on newer compositions and also includes newer approaches to address various materials issues such as in metal-ceramic sealing. The current quarter's research has also focused on developing a comprehensive reliability model for predicting the structural behavior of the membranes in realistic conditions. In parallel to industry provided compositions, models membranes have been evaluated in varying environment. Of importance is the behavior of flaws and generation of new flaws aiding in fracture. Fracture mechanics parameters such as crack tip stresses are generated to characterize the influence of environment. Room temperature slow crack growth studies have also been initiated in industry provided compositions. The electrical conductivity and defect chemistry of an A site deficient compound (La{sub 0.55}Sr{sub 0.35}FeO{sub 3}) was studied. A higher conductivity was observed for La{sub 0.55}Sr{sub 0.35}FeO{sub 3} than that of La{sub 0.60}Sr{sub 0.40}FeO{sub 3} and La{sub 0.80}Sr{sub 0.20}FeO{sub 3}. Defect chemistry analysis showed that it was primarily contributed by a higher carrier concentration in La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. Moreover, the ability for oxygen vacancy generation is much higher in La{sub 0.55}Sr{sub 0.35}FeO{sub 3} as well, which indicates a lower bonding strength between Fe-O and a possible higher catalytic activity for La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. The program continued to investigate the thermodynamic properties (stability and phase separation behavior) and total conductivity of prototype membrane materials. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previous report listed initial measurements on a sample of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-x} prepared in-house by Praxair. Subsequently, a second sample of powder from a larger batch of sample were characterized and compared with the results from the previous batch.

S. Bandopadhyay; N. Nagabhushana; Thomas W. Eagar; Harold R. Larson; Raymundo Arroyave; X.-D Zhou; Y.-W. Shin; H.U. Anderson; Nigel Browning; Alan Jacobson; C.A. Mims

2003-11-01T23:59:59.000Z

339

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, in situ neutron diffraction was used to characterize the chemical and structural properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} (here after as L2SF55T) specimen, which was subject to measurements of neutron diffraction from room temperature to 900 C. It was found that space group of R3c yielded a better refinement than a cubic structure of Pm3m. Oxygen occupancy was nearly 3 in the region from room temperature to 700 C, above which the occupancy decreased due to oxygen loss. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. The X-Ray data and fracture mechanisms points to non-equilibrium decomposition of the LSFCO OTM membrane. The non-equilibrium conditions could probably be due to the nature of the applied stress field (stressing rates) and leads to transition in crystal structures and increased kinetics of decomposition. The formations of a Brownmillerite or Sr2Fe2O5 type structures, which are orthorhombic are attributed to the ordering of oxygen vacancies. The cubic to orthorhombic transitions leads to 2.6% increase in strains and thus residual stresses generated could influence the fracture behavior of the OTM membrane. Continued investigations on the thermodynamic properties (stability and phase-separation behavior) and total conductivity of prototype membrane materials were carried out. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previously characterization, stoichiometry and conductivity measurements for samples of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} were reported. In this report, measurements of the chemical and thermal expansion as a function of temperature and p{sub O2} are described.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-05-01T23:59:59.000Z

340

Gas Separation Using Membranes  

E-Print Network (OSTI)

.133.132, May 12. 1964. 45. Kesting, R. E., Synthetic Polymeric Membranes. McGraw-Hill, N. Y. (1971). 46. Strathmann, H., Kock. K., Amar. P., and Baker, R. W., Desalination 16, 179 (1975). 47. Strathmann, H., Schel""ble, P?? and Baker. R. W?? J. Appl...?? Desalination 21. 241 (1977). 51. Cohen. C?? Tanny, G. B?? and Prager, S., J. Polym. Sci.. Polym. Phys. Ed. 17, 477 (1979). 52. Tanny, G. B., J. App], Polym. ~i. 1!. 2149 (1974). 53. Cabasso, I?? Klein, E?? and smith. J. K., "Research and Development...

Koros, W. J.; Paul, D. R.

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Ion Recognition Approach to Volume Reduction of Alkaline Tank Waste by Separation and Recycle of Sodium Hydroxide and Sodium Nitrate  

SciTech Connect

This research has focused on new liquid-liquid extraction chemistry applicable to separation of major sodium salts from alkaline tank waste. It was the overall goal to provide the scientific foundation upon which the feasibility of liquid-liquid extraction chemistry for bulk reduction of the volume of tank waste can be evaluated. Sodium hydroxide represented the initial test case and primary focus. It is a primary component of the waste1 and has the most value for recycle. A full explanation of the relevance of this research to USDOE Environmental Management needs will be given in the Relevance, Impact, and Technology Transfer section below. It should be noted that this effort was predicated on the need for sodium removal primarily from low-activity waste, whereas evolving needs have shifted attention to volume reduction of the high-activity waste. The results of the research to date apply to both applications, though treatment of high-activity wastes raises new questions that will be addressed in the renewal period. Toward understanding the extractive chemistry of sodium hydroxide and other sodium salts, it was the intent to identify candidate extractants and determine their applicable basic properties regarding selectivity, efficiency, speciation, and structure. A hierarchical strategy was to be employed in which the type of liquid-liquid-extraction system varied in sophistication from simple, single-component solvents to solvents containing designer host molecules. As an aid in directing this investigation toward addressing the fundamental questions having the most value, a conceptualization of an ideal process was advanced. Accordingly, achieving adequate selectivity for sodium hydroxide represented a primary goal, but this result is worthwhile for waste applications only if certain conditions are met.

Moyer, Bruce A.; Marchand, Alan P.; Bonnesen, Peter V.; Bryan, Jeffrey C.; Haverlock, Tamara J.

2002-03-30T23:59:59.000Z

342

Hydrogen embrittlement of type 410 stainless steel in sodium chloride, sodium sulfate, and sodium hydroxide environments at 90 C  

SciTech Connect

Susceptibility of martensitic type 410 (UNS S41000) stainless steel (SS) to environmental cracking was evaluated at 90 C in concentrated sodium chloride, sodium sulfate and sodium hydroxide solutions, all of which are environments related to steam turbine conditions, using the slow strain rate testing (SSRT) technique. In NaCl, the effects of solution pH, concentration, and anodic and cathodic polarization were investigated. Tests were supplemented by detailed electron fractography and hydrogen permeation measurements. A clear correlation was found between the degree of embrittlement and the amount of hydrogen permeating the steel, suggesting a hydrogen-induced cracking mechanism.

Gonzalez-Rodriguez, J.G.; Salinas-Bravo, V.M. [Inst. de Investigaciones Electricas, Cuernavaca (Mexico). Dept. Fisico Quimica Aplicada; Martinez-Villafane, A. [Centro de Investigaciones en Materiales Avanzados Leon Tolstoi, Chihuahua (Mexico)

1997-06-01T23:59:59.000Z

343

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped Ti-substituted perovskites, La{sub 0.7}Sr{sub 0.3}Mn{sub 1-x}Ti{sub x}O{sub 3}, with 0 {le} x {le} 0.20, were investigated by neutron diffraction, magnetization, electric resistivity, and magnetoresistance (MR) measurements. All samples show a rhombohedral structure (space group R3C) from 10 K to room temperature. At room temperature, the cell parameters a, c and the unit cell volume increase with increasing Ti content. However, at 10 K, the cell parameter a has a maximum value for x = 0.10, and decreases for x > 0.10, while the unit cell volume remains nearly constant for x > 0.10. The average (Mn,Ti)-O bond length increases up to x = 0.15, and the (Mn,Ti)-O-(Mn,Ti) bond angle decreases with increasing Ti content to its minimum value at x = 0.15 at room temperature. Below the Curie temperature TC, the resistance exhibits metallic behavior for the x {le} 0.05 samples. A metal (semiconductor) to insulator transition is observed for the x {ge} 0.10 samples. A peak in resistivity appears below TC for all samples, and shifts to a lower temperature as x increases. The substitution of Mn by Ti decreases the 2p-3d hybridization between O and Mn ions, reduces the bandwidth W, and increases the electron-phonon coupling. Therefore, the TC shifts to a lower temperature and the resistivity increases with increasing Ti content. A field-induced shift of the resistivity maximum occurs at x {le} 0.10 compounds. The maximum MR effect is about 70% for La{sub 0.7}Sr{sub 0.3}Mn{sub 0.8}Ti{sub 0.2}O{sub 3}. The separation of TC and the resistivity maximum temperature T{sub {rho},max} enhances the MR effect in these compounds due to the weak coupling between the magnetic ordering and the resistivity as compared with La{sub 0.7}Sr{sub 0.3}MnO{sub 3}. The bulk densities of the membranes were determined using the Archimedes method. The bulk density was 5.029 and 5.57 g/cc for LSFT and dual phase membranes, respectively. The microstructure of the dual phase membrane was analyzed using SEM. It is evident from the micrograph that the microstructure is composed of dual phases. The dense circular regions are enclosed by the less dense, continuous phase which accommodates most of the pores. The pores are normally aggregated and found clustered along the dense regions where as the dense regions do not have pores. Upon closer observation of the micrograph it is revealed that the dense region has a clear circular cleavage or crack as their boundary. The circular cleavage clearly encompasses a dense region and which consists of no pore or any flaw that is visible. The size distribution of the dense, discontinuous regions is varying from 5 to 20 {micro}m with a D{sub 50} of 15 {micro}m. The grain size distribution was estimated from the micrographs using image analysis and a unimodal distribution of grains was observed with an average grain size of 1.99 {micro}m. The chemical compositions of the membranes were analyzed using EDS analysis and no other impurities were observed. The XRD analysis was carried out for the membranes and the phase purity was confirmed. The fracture toughness of LSFT membranes at room temperature has to be calculated using the Vickers indentation method. An electrochemical cell has been designed and built for measurements of the ionic conductivity by the use of blocking electrodes. Preliminary measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} are reported. Modifications to the apparatus to improve the data quality have been completed. Electron microscopy studies of the origin of the slow kinetics on reduction of ferrites have been initiated. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradient

S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-05-01T23:59:59.000Z

344

Operation of staged membrane oxidation reactor systems  

SciTech Connect

A method of operating a multi-stage ion transport membrane oxidation system. The method comprises providing a multi-stage ion transport membrane oxidation system with at least a first membrane oxidation stage and a second membrane oxidation stage, operating the ion transport membrane oxidation system at operating conditions including a characteristic temperature of the first membrane oxidation stage and a characteristic temperature of the second membrane oxidation stage; and controlling the production capacity and/or the product quality by changing the characteristic temperature of the first membrane oxidation stage and/or changing the characteristic temperature of the second membrane oxidation stage.

Repasky, John Michael

2012-10-16T23:59:59.000Z

345

Spectroscopic in Situ Imaging of Acid Coextraction Processes in Solvent Polymeric Ion-Selective Electrode and Optode Membranes  

Science Journals Connector (OSTI)

Spectroscopic in Situ Imaging of Acid Coextraction Processes in Solvent Polymeric Ion-Selective Electrode and Optode Membranes ... 11 The optical and potentiometric responses can, therefore, be interrelated. ... 10 At high pH, on the other hand, the lower detection limit of the ISE is defined by an ion-exchange process, where H+ from the membrane is replaced by an interfering cation of the sample. ...

Ernö Lindner; Titus Zwickl; Eric Bakker; Bui Thi Thu Lan; Klara Tóth; Ernö Pretsch

1998-02-14T23:59:59.000Z

346

Oxygen Transport Membranes  

SciTech Connect

The focus of this research was to develop new membrane materials by synthesizing different compounds and determining their defect structures, crystallographic structures and electrical properties. In addition to measuring electrical conductivity, oxygen vacancy concentration was also evaluated using thermogravimetry, Neutron diffraction and Moessbauer Spectroscopy. The reducing conditions (CO{sub 2}/CO/H{sub 2} gas mixtures with steam) as encountered in a reactor environment can be expected to have significant influence on the mechanical properties of the oxides membranes. Various La based materials with and without Ti were selected as candidate membrane materials for OTM. The maximum electrical conductivity of LSF in air as a function of temperature was achieved at < 600 C and depends on the concentration of Sr (acceptor dopant). Oxygen occupancy in LSF was estimated using Neutron diffractometry and Moessbauer Spectroscopy by measuring magnetic moment changes depending on the Fe{sup 3+} and Fe{sup 4+} ratio. After extensive studies of candidate materials, lanthanum ferrites (LSF and LSFT) were selected as the favored materials for the oxygen transport membrane (OTM). LSF is a very good material for an OTM because of its high electronic and oxygen ionic conductivity if long term stability and mechanical strength are improved. LSFT not only exhibits p-type behavior in the high oxygen activity regime, but also has n-type conduction in reducing atmospheres. Higher concentrations of oxygen vacancies in the low oxygen activity regime may improve the performance of LSFT as an OTM. The hole concentration is related to the difference in the acceptor and donor concentration by the relation p = [Sr'{sub La}]-[Ti{sm_bullet}{sub Fe}]. The chemical formulation predicts that the hole concentration is, p = 0.8-0.45 or 0.35. Experimental measurements indicated that p is about {approx} 0.35. The activation energy of conduction is 0.2 eV which implies that LSCF conducts via the small polaron conduction mechanism. Scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) were used to develop strategies to detect and characterize vacancy creation, dopant segregations and defect association in the oxygen conducting membrane material. The pO{sub 2} and temperature dependence of the conductivity, non-stoichiometry and thermal-expansion behavior of compositions with increasing complexity of substitution on the perovskite A and B sites were studied. Studies with the perovskite structure show anomalous behavior at low oxygen partial pressures (<10{sup -5} atm). The anomalies are due to non-equilibrium effects and can be avoided by using very strict criteria for the attainment of equilibrium. The slowness of the oxygen equilibration kinetics arises from two different mechanisms. In the first, a two phase region occurs between an oxygen vacancy ordered phase such as brownmillerite SrFeO{sub 2.5} and perovskite SrFeO{sub 3-x}. The slow kinetics is associated with crossing the two phase region. The width of the miscibility gap decreases with increasing temperature and consequently the effect is less pronounced at higher temperature. The preferred kinetic pathway to reduction of perovskite ferrites when the vacancy concentration corresponds to the formation of significant concentrations of Fe{sup 2+} is via the formation of a Ruddlesden-Popper (RP) phases as clearly observed in the case of La{sub 0.5}Sr{sub 0.5}FeO{sub 3-x} where LaSrFeO{sub 4} is found together with Fe. In more complex compositions, such as LSFTO, iron or iron rich phases are observed locally with no evidence for the presence of discrete RP phase. Fracture strength of tubular perovskite membranes was determined in air and in reducing atmospheric conditions. The strength of the membrane decreased with temperature and severity of reducing conditions although the strength distribution (Weibull parameter, m) was relatively unaltered. Surface and volume dominated the fracture origins and the overall fracture was purely transgranular. The dual phas

S. Bandopadhyay

2008-08-30T23:59:59.000Z

347

Nickel-cobalt alloy nanosheets obtained from reductive hydrothermal-treatment of nickel-cobalt hydroxide carbonate  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer An anionic layered material, nickel-cobalt hydroxide carbonate was synthesized. Black-Right-Pointing-Pointer Reductive hydrothermal-treatment of the layered precursor produced an alloy. Black-Right-Pointing-Pointer The alloy is a bimetallic nanostructured nickel-cobalt and a soft magnet material. -- Abstract: Nickel-cobalt hydroxide carbonate, a layered material was synthesized by the co-precipitation method using urea as precipitant agent. This anionic layered material with hexagonal structure is constructed from nickel and cobalt ions within the layers and carbonate anions between the layers. Nickel-cobalt alloy with pure cubic phase was obtained by a reductive hydrothermal-treatment of the layered precursor. Powder X-ray diffraction pattern and Fourier transform infrared spectroscopy confirmed the formation of the initial layered material and its metallic alloy product. That is, the nickel-cobalt alloy has really produced via a wet chemical route for the first time. Magnetic measurement revealed that the alloy sample is a soft magnet material.

Ghotbi, Mohammad Yeganeh, E-mail: yeganehghotbi@gmail.com [Nanomaterials and Nanotechnology Program, Ceramic Engineering Department, Faculty of Engineering, Malayer University, Malayer (Iran, Islamic Republic of); Jolagah, Ali; Afrasiabi, Hasan-ali [Nanomaterials and Nanotechnology Program, Ceramic Engineering Department, Faculty of Engineering, Malayer University, Malayer (Iran, Islamic Republic of)] [Nanomaterials and Nanotechnology Program, Ceramic Engineering Department, Faculty of Engineering, Malayer University, Malayer (Iran, Islamic Republic of)

2012-03-15T23:59:59.000Z

348

Oxygen Transport Ceramic Membranes  

SciTech Connect

Ti doping on La{sub 1-x}Sr{sub x}FeO{sub 3-{delta}} (LSF) tends to increase the oxygen equilibration kinetics of LSF in lower oxygen activity environment because of the high valence state of Ti. However, the addition of Ti decreases the total conductivity because the acceptor ([Sr{prime}{sub La}]) is compensated by the donor ([Ti{sub Fe}{sup {sm_bullet}}]) which decreases the carrier concentration. The properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 1-x}Ti{sub x}O{sub 3-{delta}} (LSFT, x = 0.45) have been experimentally and theoretically investigated to elucidate (1) the dependence of oxygen occupancy and electrochemical properties on temperature and oxygen activity by thermogravimetric analysis (TGA) and (2) the electrical conductivity and carrier concentration by Seebeck coefficient and electrical measurements. In the present study, dual phase (La{sub 0.2}Sr{sub 0.8}Fe{sub 0.6}Ti{sub 0.4}O{sub 3-{delta}}/Ce{sub 0.9}Gd{sub 0.1}O{sub 2-{delta}}) membranes have been evaluated for structural properties such as hardness, fracture toughness and flexural strength. The effect of high temperature and slightly reducing atmosphere on the structural properties of the membranes was studied. The flexural strength of the membrane decreases upon exposure to slightly reducing conditions at 1000 C. The as-received and post-fractured membranes were characterized using XRD, SEM and TG-DTA to understand the fracture mechanisms. Changes in structural properties of the composite were sought to be correlated with the physiochemical features of the two-phases. We have reviewed the electrical conductivity data and stoichiometry data for La{sub 0.2}Sr{sub 0.8}Cr{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} some of which was reported previously. Electrical conductivity data for La{sub 0.2}Sr{sub 0.8}Cr{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCrF) were obtained in the temperature range, 752 {approx} 1055 C and in the pO{sub 2} range, 10{sup -18} {approx} 0.5 atm. The slope of the plot of log {sigma} vs. log pO{sub 2} is {approx} 1/5 in the p-type region, pO{sub 2} = 10{sup -5} {approx} 10{sup -1} atm. The pO{sub 2} at which the p-n transition is observed increases with increasing temperature. The activation energy for ionic conduction was estimated to be 0.86 eV from an Arrhenius plot of the minimum conductivity vs. reciprocal temperature. At temperatures below 940 C, a plateau in the conductivity isotherm suggests the presence of a two-phase region. Most likely, phase separation occurs to form a mixture of a perovskite phase and an oxygen vacancy ordered phase related to brownmillerite. Additional data for the oxygen non stoichiometry are presented.

S. Bandopadhyay; T. Nithyanantham

2006-12-31T23:59:59.000Z

349

Staged membrane oxidation reactor system  

DOE Patents (OSTI)

Ion transport membrane oxidation system comprising (a) two or more membrane oxidation stages, each stage comprising a reactant zone, an oxidant zone, one or more ion transport membranes separating the reactant zone from the oxidant zone, a reactant gas inlet region, a reactant gas outlet region, an oxidant gas inlet region, and an oxidant gas outlet region; (b) an interstage reactant gas flow path disposed between each pair of membrane oxidation stages and adapted to place the reactant gas outlet region of a first stage of the pair in flow communication with the reactant gas inlet region of a second stage of the pair; and (c) one or more reactant interstage feed gas lines, each line being in flow communication with any interstage reactant gas flow path or with the reactant zone of any membrane oxidation stage receiving interstage reactant gas.

Repasky, John Michael; Carolan, Michael Francis; Stein, VanEric Edward; Chen, Christopher Ming-Poh

2012-09-11T23:59:59.000Z

350

Staged membrane oxidation reactor system  

DOE Patents (OSTI)

Ion transport membrane oxidation system comprising (a) two or more membrane oxidation stages, each stage comprising a reactant zone, an oxidant zone, one or more ion transport membranes separating the reactant zone from the oxidant zone, a reactant gas inlet region, a reactant gas outlet region, an oxidant gas inlet region, and an oxidant gas outlet region; (b) an interstage reactant gas flow path disposed between each pair of membrane oxidation stages and adapted to place the reactant gas outlet region of a first stage of the pair in flow communication with the reactant gas inlet region of a second stage of the pair; and (c) one or more reactant interstage feed gas lines, each line being in flow communication with any interstage reactant gas flow path or with the reactant zone of any membrane oxidation stage receiving interstage reactant gas.

Repasky, John Michael; Carolan, Michael Francis; Stein, VanEric Edward; Chen, Christopher Ming-Poh

2014-05-20T23:59:59.000Z

351

Staged membrane oxidation reactor system  

DOE Patents (OSTI)

Ion transport membrane oxidation system comprising (a) two or more membrane oxidation stages, each stage comprising a reactant zone, an oxidant zone, one or more ion transport membranes separating the reactant zone from the oxidant zone, a reactant gas inlet region, a reactant gas outlet region, an oxidant gas inlet region, and an oxidant gas outlet region; (b) an interstage reactant gas flow path disposed between each pair of membrane oxidation stages and adapted to place the reactant gas outlet region of a first stage of the pair in flow communication with the reactant gas inlet region of a second stage of the pair; and (c) one or more reactant interstage feed gas lines, each line being in flow communication with any interstage reactant gas flow path or with the reactant zone of any membrane oxidation stage receiving interstage reactant gas.

Repasky, John Michael; Carolan, Michael Francis; Stein, VanEric Edward; Chen, Christopher Ming-Poh

2013-04-16T23:59:59.000Z

352

Oxygen Transport Ceramic Membranes  

SciTech Connect

A non-agglomerated and nanocrystalline-sized powder was successfully produced using ethylene glycol nitrate methods. The LSFT powder prepared using this method exhibits well dispersed and nano-sized particles about 100-200 nm. The density of LSFT sintered at 1300 C was about 90% of the theoretical density at which is 100 C less than that of the previous LSFT which was sintered at 1400 C. The sample sintered at 1400 C exhibited the evidence of a liquid phase at the grain boundaries and 2nd phase formation which probably caused low mechanical stability. The electrical conductivity and Seebeck coefficient were measured as a function of temperature. The LSFT-CGO specimens were cut from the as sintered bars and used for the evaluation of Mechanical Properties after polishing. The effect of strain rate on the flexural strength of the LSFT-CGO test specimens was studied. Three strain rates 6, 60 and 600 {micro}m/ min were chosen for this study. It is observed from the results that with increasing cross head speed the membrane takes higher loads to fail. A reduction in the strength of the membrane was observed at 1000 C in N{sub 2}. Two different routes were investigated to synthesis GDC using either formate or carbonate precursors. The precursor and CGO particle morphologies were examined by scanning electron microscopy. The thermal decomposition behaviors of Ce(Gd)(HCOO){sub 3} and Ce(Gd)(CO{sub 3})(OH) were determined by thermogravimetric analysis (TGA) at a rate of 3 C/min in air. The X-ray powder diffraction patterns of the precursor and CGO were collected and nitrogen adsorption isotherms were measured. Conductivity measurements were made by AC impedance spectroscopy on sintered disks in air using platinum electrodes.

S. Bandopadhyay; T. Nithyanantham

2006-06-30T23:59:59.000Z

353

Oxygen Transport Ceramic Membranes  

SciTech Connect

In the present quarter, experiments are presented on ceramic/metal interactions of Zirconia/ Ni-B-Si system and with a thin Ti coating deposited on zirconia surface. Existing facilities were modified for evaluation of environmental assisted slow crack growth and creep in flexural mode. Processing of perovskites of LSC, LSF and LSCF composition were continued for evaluation of mechanical properties as a function of environment. These studies in parallel to those on the LSFCO composition is expect to yield important information on questions such as the role of cation segregation and the stability of the perovskite structure on crack initiation vs. crack growth. Studies have been continued on the La{sub 1-x}Sr{sub x}FeO{sub 3-d} composition using neutron diffraction and TGA studies. A transition from p-type to n-type of conductor was observed at relative low pO{sub 2}, at which the majority carriers changed from the holes to electrons because of the valence state decreases in Fe due to the further loss of oxygen. Investigation on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane transport. Data obtained at 850 C show that the stoichiometry in La{sub 0.2}Sr{sub 0.8}Fe{sub 0.8}Cr{sub 0.2}O{sub 3-x} vary from {approx}2.85 to 2.6 over the pressure range studied. From the stoichiometry a lower limit of 2.6 corresponding to the reduction of all Fe{sup 4+} to Fe{sup 3+} and no reduction of Cr{sup 3+} is expected.

S. Bandopadhyay; N. Nagabhushana

2003-08-07T23:59:59.000Z

354

Use of charge-selective membranes for electrodialytic desalination of mineralized drainage collector waters  

SciTech Connect

The purpose of this work was to examine the possibility of desalination, without preliminary softening, of drainage collector waters of a medium degree mineralization, represented by a simulated solution of the same cation composition, with the use of single-charge-selective membranes. A cation-exchange membrane obtained by modification of the commercial MK-100 membrane with ethylenediamine (6), was used for this purpose. The modification was effected by treatment of the chlorosulfonated matrix with aqueous ethylenediamine solution at room temperature. The matrix, aminated on one side was then treated with concentrated NaOH solution to convert unreacted sulfonyl chloride groups into sulfo. The capacity of the modified MK-100M membrane for sulfo groups was 1.8 meq/g. The possibility of obtaining highly concentrated brines was examined at the same time.

Grebenyuk, V.D.; Veisov, B.K.; Chebotareva, R.D.; Braude, K.P.; Nefedova, G.Z.

1986-10-10T23:59:59.000Z

355

Intracellular Sequestration of Sodium by a Novel Na /H Exchanger in Yeast Is Enhanced by Mutations in the  

E-Print Network (OSTI)

membrane Na /K -ATPase, a P-type ion pump, that drives Na ions out of the cell in exchange for K ions (1). The resultant Na gradient serves as the primary energy source for the transport of other ions and metabolites threat to agricultural production worldwide (4, 5). Because of a basic similarity in ion transport

Rao, Rajini

356

Evaluation of synthetic salt water desalination by using a functionalized polysulfone based bipolar membrane electrodialysis cell  

Science Journals Connector (OSTI)

Abstract The work reported herein describes the study of desalination of synthetic salt water at laboratory scale in five different feed concentrations using a lab-made functionalized high molecular weight polysulfone (PSu) polymer based monopolar (cation exchange and anion exchange) and bipolar ion exchange membranes (with PVA as the intermediate layer) using bipolar membrane electrodialysis cell. Various parameters such as conductivity, solution pH, feed concentration, current efficiency, energy consumption, transport number, fluxes and water dissociation efficiency were determined. During the 8 h treatment under optimal conditions (i.e. time, current, higher acid and base concentrations), for the various initial feed concentrations (from 10 g/L to 50 g/L), the current efficiencies obtained ranged from 27% to 75%. And for the highest feed concentration, the highest current efficiency (? max. of about 75% for \\{PSu\\} and 63% for polystyrene divinylbenzene (PSDVB)) with lowest energy consumption (? max. of about 1.2 Wh/mol for \\{PSu\\} and 2.6 Wh/mol for PSDVB) in addition to acid-base production (? max. of about 0.018 N acid: 0.016 N base for \\{PSu\\} and 0.012 N acid: 0.013 N base for PSDVB) was observed. The results of the study demonstrated the promising potential of functionalized polysulfone based ion exchange membranes for greater water dissociation efficiency in desalination of water.

Krishnaveni Venugopal; Sangeetha Dharmalingam

2014-01-01T23:59:59.000Z

357

General Aspects of Membrane Separation Processes  

Science Journals Connector (OSTI)

This chapter focuses on the current challenges of water and wastewater treatment aiming reuse. Membrane separation processes are presented and electrodialysis is compared to pressure driven membrane processes,...

Andréa Moura Bernardes

2014-01-01T23:59:59.000Z

358

Acid Doped Membranes for High Temperature PEMFC  

Energy.gov (U.S. Department of Energy (DOE))

Presentation on Acid Doped Membranes for High Temperature PEMFC to the High Temperature Membrane Working Group, May 25, 2004 in Philadelphia, PA.

359

Theoretical and experimental investigation of membrane distillation.  

E-Print Network (OSTI)

??Invented in the 1960s, membrane distillation is an emerging technology for water treatment attracting more attention since 1980s. There are four configurations of membrane distillations… (more)

Zhang, Jianhua

2011-01-01T23:59:59.000Z

360

Webinar: Hydrogen Production by Polymer Electrolyte Membrane...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Production by Polymer Electrolyte Membrane (PEM) Electrolysis-Spotlight on Giner and Proton Webinar: Hydrogen Production by Polymer Electrolyte Membrane (PEM) Electrolysis-Spotligh...

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Extracorporeal membrane oxygenation promotes long chain fatty...  

NLE Websites -- All DOE Office Websites (Extended Search)

membrane oxygenation promotes long chain fatty acid oxidation in the immature swine heart in vivo. Extracorporeal membrane oxygenation promotes long chain fatty acid oxidation...

362

Controlling membrane protein folding using photoresponsive surfactant.  

E-Print Network (OSTI)

??Membrane proteins perform a number of roles in biological function. Membrane lipids can self assembly into numerous different phases in aqueous solution, including micelles, vesicles… (more)

Chang, Chia Hao

2012-01-01T23:59:59.000Z

363

Sandia National Laboratories: fuel cell membrane  

NLE Websites -- All DOE Office Websites (Extended Search)

membrane ECIS-Automotive Fuel Cell Corporation: Hydrocarbon Membrane Fuels the Success of Future Generation Vehicles On February 14, 2013, in CRF, Energy, Energy Efficiency,...

364

ADVANCED MATERIALS Membranes for Clean Water  

E-Print Network (OSTI)

and security. Polymer-based membrane separation technologies based on reverse osmosis, forward osmosis active layer used in reverse osmosis membranes, interfacial polymerization of trimesoyl chloride (TMC

365

New Membranes for PEM Fuel Cells  

Energy.gov (U.S. Department of Energy (DOE))

Presentation on New Membranes for PEM Fuel Cells to the High Temperature Membrane Working Group Meeting held in Arlington, Virginia, May 26,2005.

366

Fullerene-Nafion Composite Recast Membranes  

Energy.gov (U.S. Department of Energy (DOE))

Presentation on Fullerene-Nafion Composite Recast Membranes to the High Temperature Membrane Working Group Meeting held in Arlington, Virginia, May 26,2005.

367

Waste treatment by reverse osmosis and membrane processes: Industrial. (Latest citations from the EI compendex*plus database). Published Search  

SciTech Connect

The bibliography contains citations concerning the use of membranes in the treatment of industrial wastewaters. Reverse osmosis, ion exchange, electrodialysis, liquid membranes, and ultrafiltration techniques are described. Wastewater treatments for removal of metals, ammonia, sodium compounds, nitrates, fluorides, dyes, biologicals, and radioactive waste using membrane technology are discussed. Applications of this technology to the chemical, petrochemical, pulp, textile, steel, ore treatment, electro-plating, and other wastewater and groundwater-remediation industries are included.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1995-09-01T23:59:59.000Z

368

Waste treatment by reverse osmosis and membrane processes: Industrial. (Latest citations from the EI Compendex*Plus database). Published Search  

SciTech Connect

The bibliography contains citations concerning the use of membranes in the treatment of industrial wastewaters. Reverse osmosis, ion exchange, electrodialysis, liquid membranes, and ultrafiltration techniques are described. Wastewater treatments for removal of metals, ammonia, sodium compounds, nitrates, fluorides, dyes, biologicals, and radioactive waste using membrane technology are discussed. Applications of this technology to the chemical, petrochemical, pulp, textile, steel, ore treatment, electro-plating, and other wastewater and groundwater-remediation industries are included. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1993-12-01T23:59:59.000Z

369

Waste treatment by reverse osmosis and membrane processes: Industrial. (Latest citations from the Compendex database). Published Search  

SciTech Connect

The bibliography contains citations concerning the use of membranes in the treatment of industrial wastewaters. Reverse osmosis, ion exchange, electrodialysis, liquid membranes, and ultrafiltration techniques are described. Wastewater treatments for removal of metals, ammonia, sodium compounds, nitrates, fluorides, dyes, biologicals, and radioactive waste using membrane technology are discussed. Applications of this technology to the chemical, petrochemical, pulp, textile, steel, ore treatment, electro-plating, and other wastewater and groundwater-remediation industries are included. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1993-05-01T23:59:59.000Z

370

Grafted methylenediphosphonate ion exchange resins  

DOE Patents (OSTI)

An ion exchange resin is disclosed that is comprised of an insoluble copolymer onto which are grafted pendent groups that provide 1.0 to about 10 mmol/g dry weight phosphorous. The pendent groups have the formula ##STR1## wherein R is hydrogen, a cation or mixtures thereof; and R.sup.1 is hydrogen or an C.sub.1 -C.sub.2 alkyl group. The resin also contains zero to about 5 mmol/g dry weight of pendent aromatic sulfonate groups. Processes for making and using an ion exchange resin are also disclosed.

Trochimcznk, Andrzej W. (Knoxbille, TN); Gatrone, Ralph C. (Plymouth, PA); Alexandratos, Spiro (Knoxville, TN); Horwitz, E. Philip (Naperville, IL)

1997-01-01T23:59:59.000Z

371

Grafted methylenediphosphonate ion exchange resins  

DOE Patents (OSTI)

An ion exchange resin is disclosed that is comprised of an insoluble copolymer onto which are grafted pendent groups that provide 1.0 to about 10 mmol/g dry weight phosphorous. The pendent groups have the formula ##STR1## wherein R is hydrogen, a cation or mixtures thereof; and R.sup.1 is hydrogen or an C.sub.1 -C.sub.2 alkyl group. The resin also contains zero to about 5 mmol/g dry weight of pendent aromatic sulfonate groups. Processes for making and using an ion exchange-resin are also disclosed.

Trochimcznk, Andrzej W. (Knoxville, TN); Gatrone, Ralph C. (Plymouth, PA); Alexandratos, Spiro (Knoxville, TN); Horwitz, E. Philip (Naperville, IL)

1998-01-27T23:59:59.000Z

372

Softhard exchange-coupled layered structures with modulated exchange coupling  

E-Print Network (OSTI)

, Tuscaloosa, Alabama 35487-0209 Received 8 April 2003; accepted 28 June 2003 Magnetically soft/hard exchange-coupled for high performance permanent magnets in the past decades and much progress has been made in improving permanent mag- netic properties. A figure of merit of permanent magnetic materials is the maximum magnetic

Garmestani, Hamid

373

Gas Separations using Ceramic Membranes  

SciTech Connect

This project has been oriented toward the development of a commercially viable ceramic membrane for high temperature gas separations. A technically and commercially viable high temperature gas separation membrane and process has been developed under this project. The lab and field tests have demonstrated the operational stability, both performance and material, of the gas separation thin film, deposited upon the ceramic membrane developed. This performance reliability is built upon the ceramic membrane developed under this project as a substrate for elevated temperature operation. A comprehensive product development approach has been taken to produce an economically viable ceramic substrate, gas selective thin film and the module required to house the innovative membranes for the elevated temperature operation. Field tests have been performed to demonstrate the technical and commercial viability for (i) energy and water recovery from boiler flue gases, and (ii) hydrogen recovery from refinery waste streams using the membrane/module product developed under this project. Active commercializations effort teaming with key industrial OEMs and end users is currently underway for these applications. In addition, the gas separation membrane developed under this project has demonstrated its economical viability for the CO2 removal from subquality natural gas and landfill gas, although performance stability at the elevated temperature remains to be confirmed in the field.

Paul KT Liu

2005-01-13T23:59:59.000Z

374

Fabrication of graphene-encapsulated CoO/CoFe2O4 composites derived from layered double hydroxides and their application as anode materials for lithium-ion batteries  

Science Journals Connector (OSTI)

Bicomponent CoO/CoFe2O4 composites with tunable particle sizes are prepared using Co–Fe layered double hydroxides (LDHs) or Co–Fe hydroxides as precursors. Moreover, graphene-encapsulated CoO/CoFe2O4 composites (...

Dejian Du; Wenbo Yue; Yu Ren; Xiaojing Yang

2014-12-01T23:59:59.000Z

375

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, Moessbauer spectroscopy was used to study the local environmentals of LSFT with various level of oxygen deficiency. Ionic valence state, magnetic interaction and influence of Ti on superexchange are discussed Stable crack growth studies on Dense OTM bars provided by Praxair were done at elevated temperature, pressure and elevated conditions. Post-fracture X-ray data of the OTM fractured at 1000 C in environment were refined by FullProf code and results indicate a distortion of the parent cubic perovskite to orthorhombic structure with reduced symmetry. TGA-DTA studies on the post-fracture samples also indicated residual effect arising from the thermal and stress history of the samples. An electrochemical cell has been designed and built for measurements of the Seebeck coefficient as a function of temperature and pressure. The initial measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} are reported. Neutron diffraction measurements of the same composition are in agreement with both the stoichiometry and the kinetic behavior observed in coulometric titration measurements. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The COCO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-10-01T23:59:59.000Z

376

STUDYING MEMBRANE ANCHOR ORGANIZATION IN LIVING CELL MEMBRANES  

E-Print Network (OSTI)

17 Figure 2.2. PIE-FCCS acquisition generates cross-talkin Cell Membranes is Revealed by PIE-FCCS .. 11 2.115 2.3.5 PIE-

Huang, Hector Han-Li

2011-01-01T23:59:59.000Z

377

The kinetics of water sorption in Nafion membranes: a small-angle neutron scattering  

Science Journals Connector (OSTI)

The optimization of the water management in proton exchange membrane fuel cells is a major issue for the large-scale development of this technology. In addition to the operating conditions, the membrane water sorption and transport processes obviously control the water management. The main objective of this work is to provide new experimental evidence based on the use of the small-angle neutron scattering (SANS) technique in order to allow a better understanding of water sorption processes. SANS spectra were recorded for membranes equilibrated with either water vapor or liquid. Sorption kinetics data were determined and the SANS spectra were analyzed using the method developed for extracting water concentration profiles across the membrane in operating fuel cells. The water concentration profiles across the membrane are completely flat, which indicates that the water diffusion within the membrane is not the limiting process. This result provides new insight into the numerous data published on these properties. For the first time, the swelling kinetics of a Nafion membrane immersed in liquid water is studied and a complete swelling is obtained in less than 1 min.

Gérard Gebel; Sandrine Lyonnard; Hakima Mendil-Jakani; Arnaud Morin

2011-01-01T23:59:59.000Z

378

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and initial studies on newer composition of Ti doped LSF. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. In addition, studies were also begun to obtain reliable estimates of fracture toughness and stable crack growth in specific environments. Newer composition of Ti doped LSF membranes were characterized by neutron diffraction analysis. Quench studies indicated an apparent correlation between the unit cell volume and oxygen occupancy. The studies however, indicated an anomaly of increasing Fe/Ti ratio with change in heat treatment. Ti doped LSF was also characterized for stoichiometry as a function of temp and pO{sub 2}. The non stoichiometry parameter {delta} was observed to increase almost linearly on lowering pO{sub 2} until a ideal stoichiometric composition of {delta} = 0.175 was approached.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; W.B. Yelon; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-02-01T23:59:59.000Z

379

Primer on nuclear exchange models  

SciTech Connect

Basic physics is applied to nuclear force exchange models between two nations. Ultimately, this scenario approach can be used to try and answer the age old question of 'how much is enough?' This work is based on Chapter 2 of Physics of Societal Issues: Calculations on National Security, Environment and Energy (Springer, 2007 and 2014)

Hafemeister, David [Physics Department, Cal Poly University, San Luis Obispo, California (United States)

2014-05-09T23:59:59.000Z

380

HiGee Stripper-Membrane System for Decentralized Bioethanol Recovery and Purification  

Science Journals Connector (OSTI)

Fresh dilute feed (here, ethanol–water mixture) at atmospheric conditions enters the liquid distributor of the HiGee (a torus-shaped packed bed involving countercurrent vapor–liquid interaction), which is operated at vacuum conditions and is equipped with a reboiler. ... Instantaneous condensation of the permeated water vapor stream can help in creating and maintaining the rough vacuum in the permeate zone of the membrane. ... To recover the energy in the retentate stream of “membrane 2”, it is condensed in the second auxiliary heat exchanger situated prior to the reboiler of the HiGee stripper. ...

Krishna Gudena; G. P. Rangaiah; S. Lakshminarayanan

2013-02-19T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Alkaline Membrane Fuel Cell Workshop  

Energy.gov (U.S. Department of Energy (DOE))

A workshop on alkaline membrane fuel cells (AMFC) was held May 8-9, 2011, before the 2011 Hydrogen and Fuel Cells Annual Merit Review, at Crystal Gateway Marriott in Arlington, Virginia.

382

Layered plasma polymer composite membranes  

DOE Patents (OSTI)

Layered plasma polymer composite fluid separation membranes are disclosed, which comprise alternating selective and permeable layers for a total of at least 2n layers, where n is [>=]2 and is the number of selective layers. 2 figs.

Babcock, W.C.

1994-10-11T23:59:59.000Z

383

ALUMINUM READINESS EVALUATION FOR ALUMINUM REMOVAL AND SODIUM HYDROXIDE REGENRATION FROM HANFORD TANK WASTE BY LITHIUM HYDROTALCITE PRECIPITATION  

SciTech Connect

A Technology Readiness Evaluation (TRE) performed by AREV A Federal Services, LLC (AFS) for Washington River Protection Solutions, LLC (WRPS) shows the lithium hydrotalcite (LiHT) process invented and patented (pending) by AFS has reached an overall Technology Readiness Level (TRL) of 3. The LiHT process removes aluminum and regenerates sodium hydroxide. The evaluation used test results obtained with a 2-L laboratory-scale system to validate the process and its critical technology elements (CTEs) on Hanford tank waste simulants. The testing included detailed definition and evaluation for parameters of interest and validation by comparison to analytical predictions and data quality objectives for critical subsystems. The results of the TRE would support the development of strategies to further mature the design and implementation of the LiHT process as a supplemental pretreatment option for Hanford tank waste.

SAMS TL; MASSIE HL

2011-01-27T23:59:59.000Z

384

Hydrothermal synthesis of Mg–Al layered double hydroxides (LDHs) from natural brucite and Al(OH)3  

Science Journals Connector (OSTI)

By using natural brucite and Al(OH)3 as the starting materials, the Mg–Al layered double hydroxides (Mg–Al–CO3-LDHs) have been successfully synthesized via a simple hydrothermal strategy. The effect of hydrothermal synthesis temperature and reaction time on the crystal structure, grains size and Mg/Al molar ratios of Mg–Al–CO3-LDHs were investigated. The results showed that the cell parameters and Mg/Al molar ratios of the Mg–Al–CO3-LDHs increase when the hydrothermal reaction temperature increases from 140 °C to 180 °C. The size of crystal grain parallel to the direction of the layer D1 1 0 is roughly constant, while the size of crystal grain in the vertical direction of the layer D0 0 3 increases and D1 1 0/D0 0 3 decreases with the increment of hydrothermal reaction temperature.

Libing Liao; Ning Zhao; Zhiguo Xia

2012-01-01T23:59:59.000Z

385

The effect of substitution of zinc with aluminium in the brucite-like layers on the physicochemical properties of zinc-aluminium-layered double hydroxide-pamoate nanocomposite  

Science Journals Connector (OSTI)

Layered organic–inorganic hybrid materials of Zn-Al-layered double hydroxide (LDH)-pamoate nanocomposite (ZAPR) were prepared using various initial Zn/Al molar ratios (Ri) from 8:1 to 2:1 which gave initial value...

Zaemah Binti Jubri; Mohd Zobir Bin Hussein; Asmah Hj Yahaya…

2012-02-01T23:59:59.000Z

386

The aqueous phase in the interfacial synthesis of polycarbonates. Part 1. Ionic equilibria and experimental solubilities in the BPA-sodium hydroxide-water system  

Science Journals Connector (OSTI)

Part 1. Ionic equilibria and experimental solubilities in the BPA-sodium hydroxide-water system ... The effect of physicochemical properties of organic micropollutants on removal efficiencies over iron-tetrasulfophthalocyanine (FeTsPc)-immobilized Amberlite was investigated with one endocrine-disrupting chemical (EDC), bisphenol-A (BPA), and three ... ...

Philip G. Kosky; James M. Silva; Elizabeth A. Guggenheim

1991-03-01T23:59:59.000Z

387

Membrane Separations of Liquid Mixtures  

E-Print Network (OSTI)

MEMBRANE SEPARATIONS OF LIQUID MIXTURES Douglas R. Lloyd Separations Research Program Department of Chemical Engineering The University of Texas at Austin Austin, Texas In recent years considerable attention has been given to the need... for reduced energy costs in the chemical processing industry. A major portion of the energy consumed in this industry is associated with the separation and recovery of chemicals. Membrane processes offer energy-efficient, cost effective methods...

Lloyd, D. R.

388

Oxygen Transport Ceramic Membranes Quarterly Report  

E-Print Network (OSTI)

/Reaction rates in Ion 21 Transport Membranes using Isotope Tracer and Transient Kinetic Techniques CONCLUSIONS 30Oxygen Transport Ceramic Membranes Quarterly Report January 2003 ­ March 2003 Principal Authors on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane

Eagar, Thomas W.

389

Membrane Technology Workshop Summary Report, November 2012  

Energy.gov (U.S. Department of Energy (DOE))

Final report summarizing discussions held at the Membrane Technology Workshop (July 24, 2012, Rosemont, Illinois)

390

Engineering Development of Ceramic Membrane Reactor  

E-Print Network (OSTI)

ceramic Ion Transport Membrane (ITM) reactor system for low-cost conversion of natural gas to hydrogen;7 A Revolutionary Technology Using Ceramic Membranes Ion Transport Membranes (ITM) ­ Non-porous multiEngineering Development of Ceramic Membrane Reactor Systems for Converting Natural Gas to Hydrogen

391

Ninth International Workshop on Plant Membrane Biology  

SciTech Connect

This report is a compilation of abstracts from papers which were discussed at a workshop on plant membrane biology. Topics include: plasma membrane ATP-ases; plant-environment interactions, membrane receptors; signal transduction; ion channel physiology; biophysics and molecular biology; vaculor H+ pumps; sugar carriers; membrane transport; and cellular structure and function.

Not Available

1993-12-31T23:59:59.000Z

392

Chapter 1. Basic principles of membrane contactors  

Science Journals Connector (OSTI)

Publisher Summary This chapter discusses the basic principles of membrane contactors. The membrane contactors identify the membrane systems that are employed to keep two phases in contact. To avoid the mixing of the two phases, the operating pressures must be controlled. The pressure of the aqueous/polar phase has to be equal to or higher than the pressure of the wetting/filling phase. In membrane strippers and scrubbers, a liquid is in contact with a gas, the difference between the two systems being the direction in which the species are transferred: from the liquid to the gas and vice versa, respectively. In supported liquid membranes, the micropores of the membrane are filled by an organic phase and the membrane is located between two aqueous phases. Membrane distillation is the only example of membrane contactor where the driving force is related to a temperature gradient across the membrane. Osmotic distillation performs the same work of the membrane distillation but uses a different method for creating the partial pressure gradient. Membrane crystallizers represent a particular application of membrane and osmotic distillation. Membrane emulsifiers employ both hydrophobic and hydrophilic membranes for creating microemulsions. Membrane contactors can be also used to carry out catalytic reactions.

2005-01-01T23:59:59.000Z

393

Hydrogen purifier module with membrane support  

DOE Patents (OSTI)

A hydrogen purifier utilizing a hydrogen-permeable membrane to purify hydrogen from mixed gases containing hydrogen is disclosed. Improved mechanical support for the permeable membrane is described, enabling forward or reverse differential pressurization of the membrane, which further stabilizes the membrane from wrinkling upon hydrogen uptake.

A hydrogen purifier utilizing a hydrogen-permeable membrane to purify hydrogen from mixed gases containing hydrogen is disclosed. Improved mechanical support for the permeable membrane is described, enabling forward or reverse differential pressurization of the membrane, which further stabilizes the membrane from wrinkling upon hydrogen uptake.

2012-07-24T23:59:59.000Z

394

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, in situ neutron diffraction was used to characterize the chemical and structural properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} (here after as L2SF55T) specimen, which was subject to measurements of neutron diffraction from room temperature to 900 C in N{sub 2}. Space group of R3c was found to result in a better refinement and is used in this study. The difference for crystal structure, lattice parameters and local crystal chemistry for LSFT nearly unchanged when gas environment switched from air to N{sub 2}. Stable crack growth studies on Dense OTM bars provided by Praxair were done at room temperature in air. A bridge-compression fixture was fabricated to achieve stable pre-cracks from Vickers indents. Post fracture evaluation indicated stable crack growth from the indent and a regime of fast fracture. Post-fracture X-ray data of the OTM fractured at 1000 C in environment were refined by FullProf code and results indicate a distortion of the parent cubic perovskite to orthorhombic structure with reduced symmetry. TGA-DTA studies on the post-fracture samples also indicated residual effect arising from the thermal and stress history of the samples. The thermal and chemical expansion of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} were studied at 800 {le} T {le} 1000 C and at {approx} 1 x 10{sup -15} {le} pO{sub 2} {le} 0.21 atm. The thermal expansion coefficient of the sample was calculated from the dilatometric analysis in the temperature range between room temperature and 1200 C in air. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-05-01T23:59:59.000Z

395

Membrane Purification Cell for Aluminum Recycling  

SciTech Connect

Recycling mixed aluminum scrap usually requires adding primary aluminum to the scrap stream as a diluent to reduce the concentration of non-aluminum constituents used in aluminum alloys. Since primary aluminum production requires approximately 10 times more energy than melting scrap, the bulk of the energy and carbon dioxide emissions for recycling are associated with using primary aluminum as a diluent. Eliminating the need for using primary aluminum as a diluent would dramatically reduce energy requirements, decrease carbon dioxide emissions, and increase scrap utilization in recycling. Electrorefining can be used to extract pure aluminum from mixed scrap. Some example applications include producing primary grade aluminum from specific scrap streams such as consumer packaging and mixed alloy saw chips, and recycling multi-alloy products such as brazing sheet. Electrorefining can also be used to extract valuable alloying elements such as Li from Al-Li mixed scrap. This project was aimed at developing an electrorefining process for purifying aluminum to reduce energy consumption and emissions by 75% compared to conventional technology. An electrolytic molten aluminum purification process, utilizing a horizontal membrane cell anode, was designed, constructed, operated and validated. The electrorefining technology could also be used to produce ultra-high purity aluminum for advanced materials applications. The technical objectives for this project were to: - Validate the membrane cell concept with a lab-scale electrorefining cell; - Determine if previously identified voltage increase issue for chloride electrolytes holds for a fluoride-based electrolyte system; - Assess the probability that voltage change issues can be solved; and - Conduct a market and economic analysis to assess commercial feasibility. The process was tested using three different binary alloy compositions (Al-2.0 wt.% Cu, Al-4.7 wt.% Si, Al-0.6 wt.% Fe) and a brazing sheet scrap composition (Al-2.8 wt.% Si-0.7 wt.% Fe-0.8 wt.% Mn),. Purification factors (defined as the initial impurity concentration divided by the final impurity concentration) of greater than 20 were achieved for silicon, iron, copper, and manganese. Cell performance was measured using its current and voltage characteristics and composition analysis of the anode, cathode, and electrolytes. The various cells were autopsied as part of the study. Three electrolyte systems tested were: LiCl-10 wt. % AlCl3, LiCl-10 wt. % AlCl3-5 wt.% AlF3 and LiF-10 wt.% AlF3. An extended four-day run with the LiCl-10 wt.% AlCl3-5 wt.% AlF3 electrolyte system was stable for the entire duration of the experiment, running at energy requirements about one third of the Hoopes and the conventional Hall-Heroult process. Three different anode membranes were investigated with respect to their purification performance and survivability: a woven graphite cloth with 0.05 cm nominal thickness & > 90 % porosity, a drilled rigid membrane with nominal porosity of 33%, and another drilled rigid graphite membrane with increased thickness. The latter rigid drilled graphite was selected as the most promising membrane design. The economic viability of the membrane cell to purify scrap is sensitive to primary & scrap aluminum prices, and the cost of electricity. In particular, it is sensitive to the differential between scrap and primary aluminum price which is highly variable and dependent on the scrap source. In order to be economically viable, any scrap post-processing technology in the U.S. market must have a total operating cost well below the scrap price differential of $0.20-$0.40 per lb to the London Metal Exchange (LME), a margin of 65%-85% of the LME price. The cost to operate the membrane cell is estimated to be < $0.24/lb of purified aluminum. The energy cost is estimated to be $0.05/lb of purified aluminum with the remaining costs being repair and maintenance, electrolyte, labor, taxes and depreciation. The bench-scale work on membrane purification cell process has demonstrated technological advantages and subs

David DeYoung; James Wiswall; Cong Wang

2011-11-29T23:59:59.000Z

396

Wind effects on a stretched membrane heliostat  

SciTech Connect

Wind effects on stretched membrane heliostat were investigated in a boundary layer wind tunnel. The membrane response was measured at stow and representative operational conditions. It was found that both at the stow and operational conditions the mean response was much higher than the rms response. At stow conditions the largest response occurred near the leading edge of the membrane, while the rms response was the largest at the membrane center point. For the operational conditions, the largest mean and rms responses were found at the membrane centerpoint. The membrane response was significantly reduced by the membrane focusing induced through the internal underpressure.

Bienkiewicz, B. (Colorado State Univ., Fort Collins, CO (United States). Dept. of Civil Engineering)

1993-08-01T23:59:59.000Z

397

Heat Exchanger Fouling- Prediction, Measurement and Mitigation  

E-Print Network (OSTI)

The U. S. Department of Energy (DOE), Office of Industrial Programs (OIP) sponsors the development of innovative heat exchange systems. Fouling is a major and persistent cost associated with most industrial heat exchangers and nationally wastes...

Peterson, G. R.

398

SPR - Historical Oil Sales and Exchanges | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

- Historical Oil Sales and Exchanges SPR - Historical Oil Sales and Exchanges SPR - Historical Oil Sales and Exchanges More Documents & Publications SPR Annual Reports to Congress...

399

Thermohydraulic Simulation of Heat Exchanger Networks  

Science Journals Connector (OSTI)

The determination of network temperatures is carried out together with the evaluation of flow rates and pressures along the network, considering head losses in heat exchangers and associated piping. ... The HEN responsible to distribute cooling water in an industrial unit is composed by three heat exchangers in parallel. ... However, the cooling water distribution among the three exchangers presents a considerable unbalance, where heat exchanger E-101 receives much less cooling water than the design specification. ...

Viviane B. G. Tavares; Eduardo M. Queiroz; Andre? L. H. Costa

2010-04-26T23:59:59.000Z

400

Anisotropic surface tension of buckled fluid membrane  

E-Print Network (OSTI)

Solid sheets and fluid membranes exhibit buckling under lateral compression. Here, it is revealed that fluid membranes have anisotropic buckling surface tension contrary to solid sheets. Surprisingly, the surface tension perpendicular to the buckling direction shows stronger dependence than that parallel to it. Our theoretical predictions are supported by numerical simulations of a meshless membrane model. This anisotropic tension can be used to measure the membrane bending rigidity. It is also found phase synchronization occurs between multilayered buckled membranes.

Hiroshi Noguchi

2011-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

THE EXCHANGE RATE-INVESTMENT NEXUS AND EXCHANGE RATE INSTABILITY: ANOTHER REASON FOR `FEAR OF FLOATING'  

E-Print Network (OSTI)

THE EXCHANGE RATE-INVESTMENT NEXUS AND EXCHANGE RATE INSTABILITY: ANOTHER REASON FOR `FEAR repercussion comes through the reaction of firms to changed asset prices and the firms' decisions to invest: F31, F32 *Corresponding author 1 #12;THE EXCHANGE RATE-INVESTMENT NEXUS AND EXCHANGE RATE

Ahmad, Sajjad

402

EXCHANGE:  

Science Journals Connector (OSTI)

......Automatic Sampler A 7-page brochure describes the Shimadzu AOC-6, a syringe-type automatic sampler designed to automate...sampling, measurement, and injection, A system composed of an AOC-6 GC and an integrator provides completely automated GC. Features......

Exchange

1976-07-01T23:59:59.000Z

403

Advanced proton-exchange materials for energy efficient fuel cells.  

SciTech Connect

The ''Advanced Proton-Exchange Materials for Energy Efficient Fuel Cells'' Laboratory Directed Research and Development (LDRD) project began in October 2002 and ended in September 2005. This LDRD was funded by the Energy Efficiency and Renewable Energy strategic business unit. The purpose of this LDRD was to initiate the fundamental research necessary for the development of a novel proton-exchange membranes (PEM) to overcome the material and performance limitations of the ''state of the art'' Nafion that is used in both hydrogen and methanol fuel cells. An atomistic modeling effort was added to this LDRD in order to establish a frame work between predicted morphology and observed PEM morphology in order to relate it to fuel cell performance. Significant progress was made in the area of PEM material design, development, and demonstration during this LDRD. A fundamental understanding involving the role of the structure of the PEM material as a function of sulfonic acid content, polymer topology, chemical composition, molecular weight, and electrode electrolyte ink development was demonstrated during this LDRD. PEM materials based upon random and block polyimides, polybenzimidazoles, and polyphenylenes were created and evaluated for improvements in proton conductivity, reduced swelling, reduced O{sub 2} and H{sub 2} permeability, and increased thermal stability. Results from this work reveal that the family of polyphenylenes potentially solves several technical challenges associated with obtaining a high temperature PEM membrane. Fuel cell relevant properties such as high proton conductivity (>120 mS/cm), good thermal stability, and mechanical robustness were demonstrated during this LDRD. This report summarizes the technical accomplishments and results of this LDRD.

Fujimoto, Cy H.; Grest, Gary Stephen; Hickner, Michael A.; Cornelius, Christopher James; Staiger, Chad Lynn; Hibbs, Michael R.

2005-12-01T23:59:59.000Z

404

Durable, Low Cost, Improved Fuel Cell Membranes  

NLE Websites -- All DOE Office Websites (Extended Search)

Durable, Low-cost, Improved Durable, Low-cost, Improved Fuel Cell Membranes US Department of Energy Office of Hydrogen, Fuel Cells and Infrastructure Technologies Kickoff Meeting, Washington DC, February 13, 2007 Michel Fouré Project Objectives z To develop a low cost (vs. perfluorosulfonated ionomers), durable membrane. z To develop a membrane capable at 80°C at low relative humidity (25-50%). z To develop a membrane capable of operating at 120°C for brief periods of time. z To elucidate membrane degradation and failure mechanisms. U:jen/slides/pres.07/FC kickoff Washington DC 2-13-07 2 Technical Barriers Addressed z Membrane Cost z Membrane Durability z Membrane capability to operate at low relative humidity. z Membrane capability to operate at 120ºC for brief period of times.

405

High Temperature Membrane & Advanced Cathode Catalyst Development  

SciTech Connect

Current project consisted of three main phases and eighteen milestones. Short description of each phase is given below. Table 1 lists program milestones. Phase 1--High Temperature Membrane and Advanced Catalyst Development. New polymers and advanced cathode catalysts were synthesized. The membranes and the catalysts were characterized and compared against specifications that are based on DOE program requirements. The best-in-class membranes and catalysts were downselected for phase 2. Phase 2--Catalyst Coated Membrane (CCM) Fabrication and Testing. Laboratory scale catalyst coated membranes (CCMs) were fabricated and tested using the down-selected membranes and catalysts. The catalysts and high temperature membrane CCMs were tested and optimized. Phase 3--Multi-cell stack fabrication. Full-size CCMs with the down-selected and optimized high temperature membrane and catalyst were fabricated. The catalyst membrane assemblies were tested in full size cells and multi-cell stack.

Protsailo, Lesia

2006-04-20T23:59:59.000Z

406

CX-010528: Categorical Exclusion Determination | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

528: Categorical Exclusion Determination 528: Categorical Exclusion Determination CX-010528: Categorical Exclusion Determination Durability Investigation for Quarternary Phosphonium-based Polymer Hydroxide Exchange Membranes CX(s) Applied: B3.6 Date: 09/18/2012 Location(s): Delaware Offices(s): Advanced Research Projects Agency-Energy Funding will support two efforts: 1) durability testing and analysis of battery cells outfitted with the University of Delaware's novel phosphonium based polymer hydroxide exchange membrane, and 2) creation of a batch of phosphonium based polymer hydroxide exchange membranes for use in another ARPA-E project. CX-010528.pdf More Documents & Publications CX-000598: Categorical Exclusion Determination CX-009898: Categorical Exclusion Determination Energy Storage Systems 2012 Peer Review Presentations - Poster Session 1

407

Microsoft Word - 25A5311 Continued  

NLE Websites -- All DOE Office Websites (Extended Search)

X - B3.6 Siting/construction/operation/decommissioning of facilities for bench-scale research, conventional laboratory operations, small-scale research and development and pilot projects X - B3.6 Siting/construction/operation/decommissioning of facilities for bench-scale research, conventional laboratory operations, small-scale research and development and pilot projects By switching fuel cell electrochemical reactions from an acidic medium to a basic one and utilizing highly conductive hydroxide exchange membranes, the high-performance hydroxide exchange membrane fuel cells (HEMFCs) are a truly innovative technology and radically different from the proton exchange membrane fuel cells (PEMFCs) that have been intensively researched and developed in the past two decades. The most exciting ability of HEMFCs is to solve fundamentally the PEMFCs' serious problems of catalysts cost and durability, while achieving PEMFCs' high power and energy density simultaneously. What has been critically missing for HEMFCs is a polymeric hydroxide

408

Universal Membrane Classification Scheme: Maximizing the Return on High Temperature PEM Membrane Research  

Energy.gov (U.S. Department of Energy (DOE))

This presentation on maximizing the return of high temperature PEM membrane research was given at the High Temperature Membrane Working Group Meeting in May 2007.

409

Solid state oxygen anion and electron mediating membrane and catalytic membrane reactors containing them  

DOE Patents (OSTI)

A process for production of synthesis gas employing a catalytic membrane reactor wherein the membrane comprises a mixed metal oxide material.

Schwartz, Michael (Boulder, CO); White, James H. (Boulder, CO); Sammells, Anthony F. (Boulder, CO)

2001-01-01T23:59:59.000Z

410

Waste treatment by reverse osmosis and membrane processes: Industrial. November 1976-October 1989 (Citations from the COMPENDEX data base). Report for November 1976-October 1989  

SciTech Connect

This bibliography contains citations concerning the use of membranes to treat industrial waste water. Reverse osmosis, ion exchange, electrodialysis, and ultrafiltration processes are described. Removal of metals, sodium compounds, nitrates, flourides, dyes, and radioactive waste using membranes is examined. Waste-water treatment for chemical, pulp, textile, and steel mills using this technology is included. (This updated bibliography contains 294 citations, 13 of which are new entries to the previous edition.)

Not Available

1989-12-01T23:59:59.000Z

411

Waste treatment by reverse osmosis and membrane processes: industrial. January 1976-June 1989 (Citations from the COMPENDEX data base). Report for January 1976-June 1989  

SciTech Connect

This bibliography contains citations concerning the use of membranes to treat industrial waste water. Reverse osmosis, ion exchange, electrodialysis, and ultrafiltration processes are described. Removal of metals, sodium compounds, nitrates, flourides, dyes, and radioactive waste using membranes is examined. Waste-water treatment for chemical, pulp, textile, and steel mills using this technology is included. (This updated bibliography contains 281 citations, 35 of which are new entries to the previous edition.)

Not Available

1989-06-01T23:59:59.000Z

412

Waste treatment by reverse osmosis and membrane processes: industrial. January 1976-June 1988 (citations from the Engineering Index data base). Report for January 1976-June 1988  

SciTech Connect

This bibliography contains citations concerning the use of membranes to treat industrial waste water. Reverse osmosis, ion exchange, electrodialysis, and ultrafiltration processes are described. Removal of metals, sodium compounds, nitrates, flourides, dyes, and radioactive waste using membranes is examined. Wastewater treatment for chemical, pulp, textile, and steel mills using this technology is included. (This updated bibliography contains 246 citations, 26 of which are new entries to the previous edition.)

Not Available

1988-06-01T23:59:59.000Z

413

Stretched-membrane heliostat technology  

SciTech Connect

The stretched-membrane concept is a potentially low-cost and structurally efficient method of attaining and supporting a large, optically accurate surface for heliostat applications. In this concept, a high-strength structural film coated with a highly reflective surface is stretched uniformly on a torroidal frame. Prior and current research, directed at allowing the full potential of this novel concept to be realized, is described. Technical issues and results described include membrane attachment approaches, focusing, and the numerous structural response mechanisms specific to this concept.

Murphy, L.M.

1986-08-01T23:59:59.000Z

414

Production of permeable cellulose triacetate membranes  

DOE Patents (OSTI)

A phase inversion process for the preparation of cellulose triacetate (CTA) and regenerated cellulose membranes is disclosed. Such membranes are useful as supports for liquid membranes in facilitated transport processes, as microfiltration membranes, as dialysis or ultrafiltration membranes, and for the preparation of ion-selective electrodes. The process comprises the steps of preparing a casting solution of CTA in a solvent comprising a mixture of cyclohexanone and methylene chloride, casting a film from the casting solution, and immersing the cast film in a methanol bath. The resulting CTA membrane may then be hydrolyzed to regenerated cellulose using conventional techniques.

Johnson, B.M.

1986-12-23T23:59:59.000Z

415

Production of permeable cellulose triacetate membranes  

DOE Patents (OSTI)

A phase inversion process for the preparation of cellulose triacetate (CTA) and regenerated cellulose membranes is disclosed. Such membranes are useful as supports for liquid membranes in facilitated transport processes, as microfiltration membranes, as dialysis or ultrafiltration membranes, and for the preparation of ion-selective electrodes. The process comprises the steps of preparing a casting solution of CTA in a solvent comprising a mixture of cyclohexanone and methylene chloride, casting a film from the casting solution, and immersing the cast film in a methanol bath. The resulting CTA membrane may then be hydrolyzed to regenerated cellulose using conventional techniques.

Johnson, Bruce M. (Bend, OR)

1986-01-01T23:59:59.000Z

416

Membrane applications to control VOC emissions  

SciTech Connect

A thin film composite membrane to separate and recover organic vapors is briefly described. The membrane is designed for end of pipe installation with a separation efficiency of greater than 90%. The main components of the membrane system are feed compressor, vacuum pump, and membrane modules. The paper focuses on operating characteristics of the membrane, and provides data on various ideal selectivities for organics; dependence of toluene/nitrogen selectivity and stage cut on flow velocity; and dependence of plant capacity, recovery rate, pressure ratio, stage cut, retentate concentration, and specific energy consumption on membrane area for gasoline vapor separation process conditions. 5 refs., 6 figs., 1 tab.

Ohlrogge, K.; Wind, J. [GKSS Research Center, Geesthacht (Germany)

1996-12-31T23:59:59.000Z

417

Solvent-resistant microporous polymide membranes  

DOE Patents (OSTI)

An asymmetric microporous membrane with exceptional solvent resistance and highly desirable permeability is disclosed. The membrane is made by a solution-casting or solution-spinning process from a copolyamic acid comprising the condensation reaction product in a solvent of at least three reactants selected from certain diamines and dianhydrides and post-treated to imidize and in some cases cross-link the copolyamic acid. The membrane is useful as an uncoated membrane for ultrafiltration, microfiltration, and membrane contactor applications, or may be used as a support for a permselective coating to form a composite membrane useful in gas separations, reverse osmosis, nanofiltration, pervaporation, or vapor permeation.

Miller, W.K.; McCray, S.B.; Friesen, D.T.

1998-03-10T23:59:59.000Z

418

Solvent-resistant microporous polymide membranes  

DOE Patents (OSTI)

An asymmetric microporous membrane with exceptional solvent resistance and highly desirable permeability is disclosed. The membrane is made by a solution-casting or solution-spinning process from a copolyamic acid comprising the condensation reaction product in a solvent of at least three reactants selected from certain diamines and dianhydrides and post-treated to imidize and in some cases cross-link the copolyamic acid. The membrane is useful as an uncoated membrane for ultrafiltration, microfiltration, and membrane contactor applications, or may be used as a support for a permselective coating to form a composite membrane useful in gas separations, reverse osmosis, nanofiltration, pervaporation, or vapor permeation.

Miller, Warren K. (Bend, OR); McCray, Scott B. (Bend, OR); Friesen, Dwayne T. (Bend, OR)

1998-01-01T23:59:59.000Z

419

Spectroscopic studies of tryptophan and membrane- associated peptides  

E-Print Network (OSTI)

Thermodynamics of membrane protein folding measured byThermodynamics of Membrane Protein Folding: Lessons from theKim, Thermodynamics of membrane protein folding measured by

Schlamadinger, Diana Elizabeth

2011-01-01T23:59:59.000Z

420

Membrane and MEA Accelerated Stress Test Protocols | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Membrane and MEA Accelerated Stress Test Protocols Membrane and MEA Accelerated Stress Test Protocols This presentation on fuel cell membrane and MEA stress test protocols was...

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Ion exchange purification of scandium  

DOE Patents (OSTI)

An improvement in purification of scandium through ion exchange chromatography is disclosed in which the oxidation potential of the eluting solution is altered by the addition of potassium chlorate or ammonium chloride so that removal of contaminants is encouraged. The temperature, pH and concentration of the eluent HEDTA are controlled in order to maintain the scandium in the column while minimizing dilution of the scandium band. Recovery of scandium is improved by pumping dilute scandium over the column prior to stripping the scandium and precipitation. This eliminates the HEDTA ion and other monovalent cations contaminating the scandium band. This method maximizes recovery of scandium while maintaining purity. 2 figs.

Herchenroeder, L.A.; Burkholder, H.R.

1990-10-23T23:59:59.000Z

422

Protein Flips Lipids Across Membranes  

NLE Websites -- All DOE Office Websites (Extended Search)

Protein Flips Lipids Across Membranes Print Protein Flips Lipids Across Membranes Print Found ubiquitously in both bacteria and humans, membrane proteins of the adenosine triphosphate (ATP)-binding cassette (ABC) transporter family have been implicated in both antibiotic and cancer-drug resistance. The mechanisms used by these proteins to expel toxins from cells therefore represent key targets for the development of drugs designed to combat the growing problem of multidrug resistance. Toward this end, researchers from The Scripps Research Institute have succeeded in crystallizing MsbA-an ABC transporter protein-together with a substrate (the molecule to be transported) and a hydrolyzed (spent) form of the nucleotide ATP, the transporter's source of chemical energy. The resulting molecular complex is caught at a moment following the transporter's "power stroke," the force-generating part of the transport cycle. This snapshot suggests a mechanism by which the substrate molecule gets flipped head-over-tail from one side of the membrane to the other, on its way out of the cell.

423

Protein Flips Lipids Across Membranes  

NLE Websites -- All DOE Office Websites (Extended Search)

Protein Flips Lipids Across Protein Flips Lipids Across Membranes Protein Flips Lipids Across Membranes Print Wednesday, 26 October 2005 00:00 Found ubiquitously in both bacteria and humans, membrane proteins of the adenosine triphosphate (ATP)-binding cassette (ABC) transporter family have been implicated in both antibiotic and cancer-drug resistance. The mechanisms used by these proteins to expel toxins from cells therefore represent key targets for the development of drugs designed to combat the growing problem of multidrug resistance. Toward this end, researchers from The Scripps Research Institute have succeeded in crystallizing MsbA-an ABC transporter protein-together with a substrate (the molecule to be transported) and a hydrolyzed (spent) form of the nucleotide ATP, the transporter's source of chemical energy. The resulting molecular complex is caught at a moment following the transporter's "power stroke," the force-generating part of the transport cycle. This snapshot suggests a mechanism by which the substrate molecule gets flipped head-over-tail from one side of the membrane to the other, on its way out of the cell.

424

Protein Flips Lipids Across Membranes  

NLE Websites -- All DOE Office Websites (Extended Search)

Protein Flips Lipids Across Membranes Print Protein Flips Lipids Across Membranes Print Found ubiquitously in both bacteria and humans, membrane proteins of the adenosine triphosphate (ATP)-binding cassette (ABC) transporter family have been implicated in both antibiotic and cancer-drug resistance. The mechanisms used by these proteins to expel toxins from cells therefore represent key targets for the development of drugs designed to combat the growing problem of multidrug resistance. Toward this end, researchers from The Scripps Research Institute have succeeded in crystallizing MsbA-an ABC transporter protein-together with a substrate (the molecule to be transported) and a hydrolyzed (spent) form of the nucleotide ATP, the transporter's source of chemical energy. The resulting molecular complex is caught at a moment following the transporter's "power stroke," the force-generating part of the transport cycle. This snapshot suggests a mechanism by which the substrate molecule gets flipped head-over-tail from one side of the membrane to the other, on its way out of the cell.

425

Amorphous Alloy Membranes Prepared by Melt-Spin methods for Long-Term use in Hydrogen Separation Applications  

SciTech Connect

Amorphous Ni-based alloy membranes show great promise as inexpensive, hydrogenselective membrane materials. In this study, we developed membranes based on nonprecious Ni-Nb-Zr alloys by adjusting the alloying content and using additives. Several studies on crystallization of the amorphous ribbons, in-situ x-ray diffraction, SEM and TEM, hydrogen permeation, hydrogen solubility, hydrogen deuterium exchange, and electrochemical studies were conducted. An important part of the study was to completely eliminate Palladium coatings of the NiNbZr alloys by hydrogen heattreatment. The amorphous alloy (Ni0.6Nb0.4)80Zr20 membrane appears to be the best with high hydrogen permeability and good thermal stability.

Chandra, Dhanesh; Kim, Sang-Mun; Adibhatla, Anasuya; Dolan, Michael; Paglieri, Steve; Flanagan, Ted; Chien, Wen-Ming; Talekar, Anjali; Wermer, Joseph

2013-02-28T23:59:59.000Z

426

Microporous Inorganic Membranes for Hydrogen Purification  

NLE Websites -- All DOE Office Websites (Extended Search)

Microporous Microporous Inorganic Membranes for Hydrogen Purification Brian L. Bischoff, Roddie R. Judkins, and Timothy R. Armstrong Oak Ridge National Laboratory Presented at: DOE Workshop on Hydrogen Separations and Purification Technologies Arlington, Virginia September 8, 2004 2 OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY Hydrogen Separation Membranes * Non-Porous - Palladium based films - Ion transport membranes * Porous - Ordered microporous membranes (IUPAC Recommendations 2001), e.g. zeolite membranes - Microporous membranes 3 OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY Microporous Membranes * IUPAC defines micropores as pores smaller than 2nm in diameter * Generally a microporous membrane is made by applying 1 to 3 thin layers to a porous support * Porous support can be ceramic or metallic

427

Composite carbon-ceramic hollow fiber membranes  

SciTech Connect

This work describes the synthesis of a new type of composite membrane by applying porous ceramic layers onto the surface of carbon membranes using the sol-gel process. The pore structure is discussed.

Linkov, V.M.; Kaiser, K.; Sanderson, R.; Lapidus, A.L. [Rossiiskaya Akademiya, Nauk (Russian Federation)

1994-12-31T23:59:59.000Z

428

Hybrid Membranes for Light Gas Separations  

E-Print Network (OSTI)

Membrane separations provide a potentially attractive technology over conventional processes due to their advantages, such as low capital cost and energy consumption. The goal of this thesis is to design hybrid membranes that facilitate specific gas...

Liu, Ting

2012-07-16T23:59:59.000Z

429

Energy Conservation Possibilities Using Gas Separating Membranes  

E-Print Network (OSTI)

The separation of gases using semi permeable membranes is a viable unit operation. A novel composite membrane combined with hollow fiber spinning technology enable Monsanto Co. to offer PRISM (TM); Separators to the industrial market. The separator...

Knieriem, H.; Henis, J. M. S.

1980-01-01T23:59:59.000Z

430

membrane-mtr | netl.doe.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

developing a new type of membrane contactor (or mega-module) to separate carbon dioxide (CO2) from power plant flue gas. This module's membrane area is 500 square meters, 20 to 25...

431

Energy Recovery Ventilator Membrane Efficiency Testing  

E-Print Network (OSTI)

A test setup was designed and built to test energy recovery ventilator membranes. The purpose of this test setup was to measure the heat transfer and water vapor transfer rates through energy recover ventilator membranes and find their effectiveness...

Rees, Jennifer Anne

2013-05-07T23:59:59.000Z

432

Single Molecule Probes of Lipid Membrane Structure  

E-Print Network (OSTI)

structural metrics with function in biological membranes. Single-molecule fluorescence studies were used to measure membrane structure at the molecular level. Several groups have shown that polarized total internal reflection fluorescence microscopy (PTIRF...

Livanec, Philip W.

2009-12-14T23:59:59.000Z

433

Electrodialysis with Bipolar Membranes for Sustainable Development  

Science Journals Connector (OSTI)

Electrodialysis with Bipolar Membranes for Sustainable Development ... A mathematical model of a typical three-compartment electrodialysis with bipolar membranes (EDBM) process has been developed to calculate the energy consumption and total cost of the process. ...

Chuanhui Huang; Tongwen Xu

2006-07-22T23:59:59.000Z

434

Ni catalysts derived from Mg–Al layered double hydroxides for hydrogen production from landfill gas conversion  

Science Journals Connector (OSTI)

A layered double hydroxide (LDH) precursor with a hydrotalcite-like structure containing Ni/Mg/Al cations was prepared. A series of Ni catalysts containing mixed-oxides and spinel phases were then obtained through thermal treatment of the LDH precursor. X-ray diffraction (XRD), transmission electron microscopy (TEM), and temperature-programmed reduction (TPR) revealed that the LDH derived Ni catalysts have well-dispersed nickel phases upon reduction. The thermal treatment temperatures have noticeable effects on the specific surface area, pore volume, phase transformation, particle size, and reducibility of the catalysts. Thermal treatment temperatures up to 700 °C promote the generation of mesopores which facilitate an increase in specific area and pore volume. Beyond 700 °C sintering occurs, mesopores collapse, and specific area and pore volume decrease. High thermal treatment temperatures favor the phase transformation to spinel solid solutions and the particle size growth. Metal-support interaction is enhanced but reducibility is hindered due to the formation of spinel solid solution phases. The LDH derived Ni catalysts were tested for landfill gas conversion at 750 °C and have shown excellent activity and stability in terms of methane conversion. At gas hourly space velocity (GHSV) of 240,000 h?1 and pressure of 1 atm, 81% methane conversion was achieved during a 48 h test period without apparent catalyst deactivation.

Qingsong Wang; Wei Ren; Xueliang Yuan; Ruimin Mu; Zhanlong Song; Xiaolin Wang

2012-01-01T23:59:59.000Z

435

Templating Effects on the Mineralization of Layered Inorganic Compounds:? (1) Density Functional Calculations of the Formation of Single-Layered Magnesium Hydroxide as a Brucite Model  

Science Journals Connector (OSTI)

Templating Effects on the Mineralization of Layered Inorganic Compounds:? (1) Density Functional Calculations of the Formation of Single-Layered Magnesium Hydroxide as a Brucite Model ... This work aims at understanding the formation and stability of a layered structure of brucite mineral [Mg(OH)2] via density functional calculations. ... It has been confirmed that this polymerization reaction leads spontaneously to a planar cluster, which is regarded as a part of the brucite layer. ...

Hisako Sato; Akihiro Morita; Kanta Ono; Haruyuki Nakano; Noboru Wakabayashi; Akihiko Yamagishi

2003-07-12T23:59:59.000Z

436

ALUMINUM REMOVAL AND SODIUM HYDROXIDE REGENERATION FROM HANFORD TANK WASTE BY LITHIUM HYDROTALCITE PRECIPITATION SUMMARY OF PRIOR LAB-SCALE TESTING  

SciTech Connect

Scoping laboratory scale tests were performed at the Chemical Engineering Department of the Georgia Institute of Technology (Georgia Tech), and the Hanford 222-S Laboratory, involving double-shell tank (DST) and single-shell tank (SST) Hanford waste simulants. These tests established the viability of the Lithium Hydrotalcite precipitation process as a solution to remove aluminum and recycle sodium hydroxide from the Hanford tank waste, and set the basis of a validation test campaign to demonstrate a Technology Readiness Level of 3.

SAMS TL; GUILLOT S

2011-01-27T23:59:59.000Z

437

Local environment and composition of magnesium gallium layered double hydroxides determined from solid-state 1H and 71Ga NMR spectroscopy  

SciTech Connect

Ordering of gallium(III) in a series of magnesium gallium layered double hydroxides (LDH’s), [Mg1-xGax(OH)2(NO3)x yH2O], was determined using solid-state 1H and 71Ga NMR spectroscopy. Depletion of Ga in these LDH’s is demonstrated to be the result of soluble [Ga(OH)4]-complexes formed during synthesis.

Petersen, Line B.; Lipton, Andrew S.; Zorin, Vadim; Nielsen, Ulla Gro

2014-11-01T23:59:59.000Z

438

Table II: Technical Targets for Membranes: Automotive  

Energy.gov (U.S. Department of Energy (DOE))

Technical targets for fuel cell membranes in automotive applications defined by the High Temperature Working Group (February 2003).

439

Challenges in Bio-Inspired Membranes  

Energy.gov (U.S. Department of Energy (DOE))

Presentation by Jun Lin (Pacific Northwest National Laboratory, PNNL) for the Membrane Technology Workshop held July 24, 2012

440

Review of Historical Membrane Workshop Results  

Energy.gov (U.S. Department of Energy (DOE))

Presentation by Sharon Robinson (Oak Ridge National Laboratory) for the Membrane Technology Workshop held July 24, 2012

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Table IV: Technical Targets for Membranes: Stationary  

Energy.gov (U.S. Department of Energy (DOE))

"Technical targets for fuel cell membranes in stationary applications defined by the High Temperature Working Group (February 2003). "

442

Agenda: High Temperature Membrane Working Group Meeting  

Energy.gov (U.S. Department of Energy (DOE))

Agenda for the High Temperature Membrane Working Group (HTMWG) meeting on May 18, 2009, in Arlington, Virginia

443

DHE (downhole heat exchangers). [Downhole Heat Exchangers (DHE)  

SciTech Connect

The use of downhole heat exchangers (DHE) for residential or commercial space and domestic water heating and other applications has several desirable features. Systems are nearly or completely passive -- that is, no or very little geothermal water or steam is produced from the well either reducing or completely eliminating surface environmental concerns and the need for disposal systems or injection wells. Initial cost of pumps and installation are eliminated or reduced along with pumping power costs and maintenance costs associated with pumping often corrosive geothermal fluids. Many residential and small commercial systems do not require circulating pumps because the density difference in the incoming and outgoing sides of the loop are sufficient to overcome circulating friction losses in the entire system. The major disadvantage of DHEs is their dependence on natural heat flow. In areas where geological conditions provide high permeability and a natural hydraulic gradient, DHEs can provide a substantial quantity of heat. A single 500-ft (152 m) well in Klamath Falls, Oregon, supplies over one megawatt thermal and output is apparently limited by the surface area of pipe that can be installed in the well bore. In contrast, DHEs used in conjunction with heat pumps may supply less than 8 KW from a well of similar depth. Here output is limited by conductive heat flow with perhaps a small contribution from convection near the well bore. The highest capacity DHE reported to date, in Turkey, supplies 6 MW thermal from an 820-ft (250 m) well. There were two main goals for this project. The first was to gather, disseminate and exchange internationally information on DHES. The second was to perform experiments that would provide insight into well bore/aquifer interaction and thereby provide more information on which to base DHE designs. 27 refs., 31 figs., 3 tabs.

Culver, G.

1990-11-01T23:59:59.000Z

444

Exchange Fluctuation Theorem for correlated quantum systems  

E-Print Network (OSTI)

We extend the Exchange Fluctuation Theorem for energy exchange between thermal quantum systems beyond the assumption of molecular chaos, and describe the non-equilibrium exchange dynamics of correlated quantum states. The relation quantifies how the tendency for systems to equilibrate is modified in high-correlation environments. Our results elucidate the role of measurement disturbance for such scenarios. We show a simple application by finding a semi-classical maximum work theorem in the presence of correlations.

Sania Jevtic; David Jennings; Terry Rudolph; Yuji Hirono; Shojun Nakayama; Mio Murao

2014-12-04T23:59:59.000Z

445

Waste treatment by reverse osmosis and membrane processes: Industrial. (Latest citations from the EI Compendex*plus database). NewSearch  

SciTech Connect

The bibliography contains citations concerning the use of membranes in the treatment of industrial wastewaters. Reverse osmosis, ion exchange, electrodialysis, liquid membranes, and ultrafiltration techniques are described. Wastewater treatments for removal of metals, ammonia, sodium compounds, nitrates, fluorides, dyes, biologicals, and radioactive waste using membrane technology are discussed. Applications of this technology to the chemical, petrochemical, pulp, textile, steel, ore treatment, electro-plating, and other wastewater and groundwater-remediation industries are included. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1994-10-01T23:59:59.000Z

446

Identification and Characterization of Near-Term Direct Hydrogen Proton Exchange Membrane Fuel Cell Markets  

NLE Websites -- All DOE Office Websites (Extended Search)

This report is a work prepared for the United States Government by Battelle. In no event shall either the United States Government or Battelle have any responsibility or liability for any consequences of any use, misuse, inability to use, or reliance on the information contained herein, nor does either warrant or otherwise represent in any way the accuracy, adequacy, efficacy, or applicability of the contents hereof. ii TABLE OF CONTENTS 1.0 INTRODUCTION ........................................................................................................ 1 1.1 Marketing Research Design.......................................................................................... 2 1.1.1 Phase 1 Research .............................................................................................

447

Electrical coupling in proton exchange membrane fuel cell stacks: mathematical and computational modelling  

Science Journals Connector (OSTI)

......unique solution (the equations force all other cells to run at this...and voltage, V . The scaled fundamental voltage equation (21) forces the voltage to be constant...HODGMAN, C. (ed.) (1959) Handbook of Chemistry and Physics......

Peter Berg; Atife Caglar; Keith Promislow; Jean St-Pierre; Brian Wetton

2006-04-01T23:59:59.000Z

448

A feasibility study of internal evaporative cooling for proton exchange membrane fuel cells  

E-Print Network (OSTI)

of internal evaporative cooling of the PEM fuel cell is to introduce finely atomized liquid water into the anode gas stream, so that the finely atomized liquid water adsorbs onto the anode and then moves to the cathode via electro-osmotic drag, where...

Snyder, Loren E

2006-04-12T23:59:59.000Z

449

-Supporting Information-2 Patterned ion exchange membranes for improved power production in4  

E-Print Network (OSTI)

production in4 microbial reverse-electrodialysis cells5 6 Jia Liua , Geoffrey M. Geisea, b , Xi Luoc

450

Increasing Proton Exchange Membrane Fuel Cell Catalyst Effectiveness Through Sputter Deposition  

E-Print Network (OSTI)

, University of South Carolina, Columbia, South Carolina 29208, USA b Plug Power, Incorporated, Latham, New and carbon- supported catalyst.3-6 It is this three-phase interface of catalyst, car- bon, and electrolyte typically Nafion® that allows effective gas and water diffusion and proton transport and electron transport

451

Haemocompatibility and ion exchange capability of nanocellulose polypyrrole membranes intended for blood purification  

Science Journals Connector (OSTI)

...the use of ex vivo flow systems to measure the dynamic...heparinized composite after steam sterilization 8 2 non-heparinized...microextraction: a new tool for clinical analysis...platelets and the coagulation system. In Platelets (ed...biocompatibility by parallel assessment in an ex vivo model in...

2012-01-01T23:59:59.000Z

452

E-Print Network 3.0 - anion-exchange membrane fuel Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

of Mechanical Engineering, Hong Kong University of Science and Technology Collection: Energy Storage, Conversion and Utilization ; Chemistry 2 IP Pragmatics Limited, 1 Quality...

453

Optimization of channel geometry in a proton exchange membrane (PEM) fuel cell.  

E-Print Network (OSTI)

??Bipolar plates are the important components of the PEM fuel cell. The flow distribution inside the bipolar plate should be uniform. Non-uniform flow distribution inside… (more)

Kasukurthi, Jephanya

2009-01-01T23:59:59.000Z

454

SEPARATION OF PROTEINS BY ION EXCHANGE AND MEMBRANE CHROMATOGRAPHY: BUFFER COMPOSITION, INTERFERING IMPURITIES AND FOULING CONSIDERATIONS  

E-Print Network (OSTI)

on identifying major impurity and optimization of solution properties for target protein purification. The second approach consisted of designing an adsorbent that interacted specifically with the target molecule. The first study included modification of protein...

Imam, Tahmina

2010-01-16T23:59:59.000Z

455

NETL's Energy Data eXchange  

ScienceCinema (OSTI)

A brief tour around NETL's Energy Data Exchange site, where researchers can upload data or look at data from another researcher.

None

2014-07-22T23:59:59.000Z

456

COMPACT HEAT EXCHANGERS FOR CONDENSATION APPLICATIONS: YESTERDAY...  

Office of Scientific and Technical Information (OSTI)

or allow other to do so, for U. S. Government purposes, i I ABSTRACT Compact heat exchangers are being increasinglyconsidered for condensationapplications in the...

457

Heat transfer and heat exchangers reference handbook  

SciTech Connect

The purpose of this handbook is to provide Rocky Flats personnel with an understanding of the basic concepts of heat transfer and the operation of heat exchangers.

Not Available

1991-01-15T23:59:59.000Z

458

"Heat Exchange Enhancing Insert" Inventors .--.. Andrei Khodak...  

NLE Websites -- All DOE Office Websites (Extended Search)

Heat Exchange Enhancing Insert" Inventors .--.. Andrei Khodak, Michael A. Jaworski A new shape of the heat enhancing insert is proposed. This device creates an impinging jet...

459

Technology Performance Exchange | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Performance Exchange Performance Exchange Technology Performance Exchange A collaboration between the U.S. Department of Energy's (DOE's) Federal Energy Management Program Office and the Building Technologies Office, the Technology Performance Exchange will establish a Web-based portal and accompanying database that allows technology suppliers to submit product performance data that private and public sector end users can use to make fact-based procurement decisions. Suppliers will populate the database with technologies that affect building activities, including construction, commissioning, maintenance, monitoring, equipment, and verification. This project will help the U.S. energy efficiency technology market by providing objective product performance data to building engineers and

460

PEM Electrolyzer Incorporating an Advanced Low Cost Membrane  

Energy Savers (EERE)

Virginia Tech University (Academic)- Membrane Development Collaborations 3M Fuel Cell Components Program- NSTF Catalyst & Membrane Entegris - Carbon Cell Separators...

Note: This page contains sample records for the topic "hydroxide exchange membranes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Quality Assurance Exchange August 2012  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

With the help of dedicated quality With the help of dedicated quality professionals across the complex and beyond, I am pleased to announce that this issue of the Quality Assurance Exchange (QAE) newsletter focuses on hard hitting issues, as well as opportunities to explore abatement methods in regards to our quality assurance (QA) challenges. Within, you will find a brief discussion on the Department of Energy (DOE) Federal Quality Council and its Calendar Year 2011 accomplishments; an exploration of Safety Software QA activities including an overview of the annual meeting; an update on the Safety Software Communication Forum; and activities surrounding new and upcoming guides and systems. Also, you will get an inside look on the Differing Professional Opinions Process; read an exclusive interview

462

Membranes solve North Sea waterflood sulfate problems  

SciTech Connect

To prevent barium sulfate scale from forming in the North Sea Brae field producing wells, Marathon Oil Co. UK Ltd. is successfully employing thin-film composite (nanofiltration) membranes for removing sulfate from injected seawater. In the early 1980s, FilmTec Corp., a Dow Chemical Co. subsidiary, first developed these composite membranes, which now are in their third generation. Marathon Oil Co. holds the patent for the specific nanofiltration membrane process for mitigating scale formation and deleterious reservoir effects. This first article in a three-part series describes membrane technology. The remaining articles detail specific membrane performance characteristics and field experiences in the Brae fields.

Davis, R. [Dow Chemical Co., Midland, MI (United States); Lomax, I. [Dow Chemical Co., Dubai (United Arab Emirates); Plummer, M. [Marathon Oil Co., Littleton, CO (United States)

1996-11-25T23:59:59.000Z

463

Process for restoring membrane permeation properties  

DOE Patents (OSTI)

A process for restoring the selectivity of high-flee-volume, glassy polymer membranes for condensable components over less-condensable components or non-condensable components of a gas mixture. The process involves exposing the membrane to suitable sorbent vapor, such as propane or butane, thereby reopening the microvoids that make up the free volume. The selectivity of an aged membrane may be restored to 70-100% of its original value. The selectivity of a membrane which is known to age over time can also be maintained by keeping the membrane in a vapor environment when it is not in use.

Pinnau, Ingo (Palo Alto, CA); Toy, Lora G. (San Francisco, CA); Casillas, Carlos G. (San Jose, CA)

1997-05-20T23:59:59.000Z

464

Process for restoring membrane permeation properties  

DOE Patents (OSTI)

A process is described for restoring the selectivity of high-free-volume, glassy polymer membranes for condensable components over less-condensable components or non-condensable components of a gas mixture. The process involves exposing the membrane to suitable sorbent vapor, such as propane or butane, thereby reopening the microvoids that make up the free volume. The selectivity of an aged membrane may be restored to 70--100% of its original value. The selectivity of a membrane which is known to age over time can also be maintained by keeping the membrane in a vapor environment when it is not in use. 8 figs.

Pinnau, I.; Toy, L.G.; Casillas, C.G.

1997-05-20T23:59:59.000Z

465

Pollution prevention drives membrane technologies  

SciTech Connect

Currently, such membrane technologies as crossflow micro-, ultra-, and nanofiltration, reverse osmosis, electrodialysis and pervaporation offer interesting possibilities, each tackling a specific aspect of pollution control. Although none of these methods can, on its own, alter or break down pollutants, each has the ability to separate, fractionate and concentrate contaminants. In addition, they: permit continuous, uninterrupted processing via automatic control; use far less energy than traditional treatment methods; require only minimal temperature changes and no chemical additives; exert no impact on contaminants, and keep them physically separated from the stream; and are easy to install, either alone or combined with other treatment systems, since they are modular and contain few moving parts. The paper discusses the benefits and disadvantages of membrane technology and recommends thorough testing.

Cartwright, P.

1994-09-01T23:59:59.000Z

466

NETL: Hydrogen Selective Exfoliated Zeolite Membranes  

NLE Websites -- All DOE Office Websites (Extended Search)

Hydrogen Selective Exfoliated Zeolite Membranes Hydrogen Selective Exfoliated Zeolite Membranes Project No.: DE-FE0001322 The University of Minnesota is developing a technically and economically viable membrane for carbon dioxide (CO2) separation from typical water-gas-shift (WGS) mixture feeds. The goal of this project is to further develop recently developed membrane technology based on exfoliated zeolite coatings as components for carbon capture in integrated gasification combined cycle plants. These membranes have the potential to contribute to carbon capture by high-temperature separation of hydrogen from CO2 and other gases present in shifted synthesis gas. Molecular sieve membrane for the pre-combustion capture of CO2. Molecular sieve membrane for the pre-combustion capture of CO2. Related Papers and Publications:

467

Ion transport membrane module and vessel system  

DOE Patents (OSTI)

An ion transport membrane system comprising (a) a pressure vessel having an interior, an exterior, an inlet, and an outlet; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein any inlet and any outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; and (c) one or more gas manifolds in flow communication with interior regions of the membrane modules and with the exterior of the pressure vessel. The ion transport membrane system may be utilized in a gas separation device to recover oxygen from an oxygen-containing gas or as an oxidation reactor to oxidize compounds in a feed gas stream by oxygen permeated through the mixed metal oxide ceramic material of the membrane modules.

Stein, VanEric Edward (Allentown, PA); Carolan, Michael Francis (Allentown, PA); Chen, Christopher M. (Allentown, PA); Armstrong, Phillip Andrew (Orefield, PA); Wahle, Harold W. (North Canton, OH); Ohrn, Theodore R. (Alliance, OH); Kneidel, Kurt E. (Alliance, OH); Rackers, Keith Gerard (Louisville, OH); Blake, James Erik (Uniontown, OH); Nataraj, Shankar (Allentown, PA); Van Doorn, Rene Hendrik Elias (Obersulm-Willsbach, DE); Wilson, Merrill Anderson (West Jordan, UT)

2012-02-14T23:59:59.000Z

468

Ion transport membrane module and vessel system  

DOE Patents (OSTI)

An ion transport membrane system comprising (a) a pressure vessel having an interior, an exterior, an inlet, and an outlet; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein any inlet and any outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; and (c) one or more gas manifolds in flow communication with interior regions of the membrane modules and with the exterior of the pressure vessel.The ion transport membrane system may be utilized in a gas separation device to recover oxygen from an oxygen-containing gas or as an oxidation reactor to oxidize compounds in a feed gas stream by oxygen permeated through the mixed metal oxide ceramic material of the membrane modules.

Stein, VanEric Edward (Allentown, PA); Carolan, Michael Francis (Allentown, PA); Chen, Christopher M. (Allentown, PA); Armstrong, Phillip Andrew (Orefield, PA); Wahle, Harold W. (North Canton, OH); Ohrn, Theodore R. (Alliance, OH); Kneidel, Kurt E. (Alliance, OH); Rackers, Keith Gerard (Louisville, OH); Blake, James Erik (Uniontown, OH); Nataraj, Shankar (Allentown, PA); van Doorn, Rene Hendrik Elias (Obersulm-Willsbach, DE); Wilson, Merrill Anderson (West Jordan, UT)

2008-02-26T23:59:59.000Z

469

Photo-switchable membrane and method  

DOE Patents (OSTI)

Switchable gas permeation membranes in which a photo-switchable low-molecular-weight liquid crystalline (LC) material acts as the active element, and a method of making such membranes. Different LC eutectic mixtures were doped with mesogenic azo dyes and infused into track-etched porous membranes with regular cylindrical pores. Photo-induced isothermal phase changes in the imbibed mesogenic material afforded large, reversible changes in the permeability of the photo-switchable membrane to nitrogen. For example, membranes imbibed with a photo-switchable cyanobiphenyl LC material demonstrated low permeability in the nematic state, while the photo-generated isotropic state demonstrated a 16.times.-greater sorption coefficient. Both states obey a high linear sorption behavior in accordance with Henry's Law. In contrast, membranes imbibed with a photo-switchable phenyl benzoate LC material showed the opposite permeability behavior to the biphenyl-imbibed membrane, along with nonlinear sorption behavior.

Marshall, Kenneth L; Glowacki, Eric

2013-05-07T23:59:59.000Z

470

Hydrogen Selective Exfoliated Zeolite Membranes  

NLE Websites -- All DOE Office Websites (Extended Search)

Hydrogen Selective Exfoliated Zeolite Hydrogen Selective Exfoliated Zeolite Membranes Background An important component of the Department of Energy (DOE) Carbon Sequestration Program is the development of carbon capture technologies for power systems. Capturing carbon dioxide (CO 2 ) from mixed-gas streams is a first and critical step in carbon sequestration. To be technically and economically viable, a successful separation method must be applicable to industrially relevant gas streams at realistic

471

Ion Recognition Approach to Volume Reduction of Alkaline Tank Waste by Separation and Recycle of Sodium Hydroxide and Sodium Nitrate  

SciTech Connect

The objective of this research is to explore new liquid-liquid extraction approaches to the selective separation of major sodium salts from alkaline high-level wastes stored in underground tanks at Hanford, Savannah River, and Oak Ridge sites. Disposal of high level waste is horrendously expensive, in large part because the actual radioactive matter in the tanks has been diluted over 1000-fold by ordinary inorganic chemicals. Since the residual bulk chemicals must still undergo expensive treatment and disposal after most of the hazardous radionuclides have been removed, large cost savings will result from processes that reduce the overall waste volume. It is proposed that major cost savings can be expected if sodium hydroxide needed for sludge washing can be obtained from the waste itself, thus avoiding the addition of yet another bulk chemical to the waste and still further increase of the waste volume and disposal cost. Secondary priority is given to separating potassium an d abundant anions, including nitrate, nitrite, aluminate, and carbonate. Salts of these ions represent possible additional value for recycle, alternative disposal, or even use as commodity chemicals. A comprehensive approach toward understanding the extractive chemistry of these salts is envisioned, involving systems of varying complexity, from use of simple solvents to new bifunctional host molecules for ion-pair recognition. These extractants will ideally require no adjustment of the waste composition and will release the extracted salt into water, thereby consuming no additional chemicals and producing no additional waste volume. The overall goal of this research is to provide a scientific foundation upon which the feasibility of new liquid-liquid extraction chemistry applicable to the bulk reduction of the volume of tank waste can be evaluated.

Moyer, Bruce A.; Marchand, Alan P.; Bryan, Jeffrey C.; Bonnesen, Peter V.

1999-06-01T23:59:59.000Z

472

Building Energy Data Exchange Specification Scoping Report  

Energy.gov (U.S. Department of Energy (DOE))

Building Energy Data Exchange Specification Scoping Report. The Building Energy Data Exchange Specification (BEDES), developed by DOE, is a uniform format is intended to make it easier for external stakeholders to use DOE tools, streamline reporting for DOE programs, and help unlock the full utility of the data that the DOE collects.

473

Cryogenic heat exchanger with turbulent flows  

Science Journals Connector (OSTI)

An evaporator-type cryogenic heat exchanger is designed and built for introducing fluid–solid heat exchange phenomena to undergraduates in a practical and efficient way. The heat exchanger functions at liquid nitrogen temperature and enables cooling of N2 and He gases from room temperatures. We present first the experimental results of various parameters which characterize the heat exchanger (efficiency, number of transfer units, heat exchange coefficient, etc) as a function of the mass flow rate of the gas to be cooled. An analysis of the Nu–Re diagram is also presented. All experiments were conducted with N2 gas. The scope of this tool is readily extended to research purposes.

Jay Amrit; Christelle Douay; Francis Dubois; Gérard Defresne

2012-01-01T23:59:59.000Z

474

Korea Power Exchange (KPX) | Open Energy Information  

Open Energy Info (EERE)

Exchange (KPX) Exchange (KPX) Jump to: navigation, search Logo: Korea Power Exchange (KPX) Name Korea Power Exchange (KPX) Agency/Company /Organization Argonne National Laboratory Sector Energy Focus Area Energy Efficiency Topics Background analysis Website http://www.dis.anl.gov/news/Ko Country South Korea Eastern Asia References http://www.dis.anl.gov/news/KoreaKpxIit.html Abstract In an agreement signed on March 26, 2007, Argonne National Laboratory and the Illinois Institute of Technology are joining with the Korea Power Exchange to establish a joint training program combining training and research at Argonne with formal academic education at IIT. Argonne-IIT Joint Graduate Program in Electricity Markets: In an agreement signed on March 26, 2007, Argonne National Laboratory and the Illinois

475

Final Report: Computer Simulation of Osmosis and Reverse Osmosis in Structured Membranes  

SciTech Connect

Molecular simulation methods were developed as part of this project to increase our fundamental understanding of membrane based separation systems. Our simulations clarified for example that steric (size) effects had a significant impact on the desalination membranes. Previously it was thought the separation was entirely driven by coulombic force (attractive/repulsive forces at the membrane surfaces). Steric effects played an important role, because salt ions in brackish water are never present alone, but are strongly hydrated which effectively increases their size, and makes it impossible to enter a membrane, while the smaller water molecules can enter more readily. Membrane surface effects did play a role in increasing the flux of water, but not in the separation itself. In addition we also developed simulation methods to study ion exchange, gas separations, and pervaporation. The methods developed were used to once again increase our fundamental understanding of these separation processes. For example our studies showed that when the separation factor of gases in membranes can be significantly affected by the presence of another gas, it is generally because the separation mechanism has changed. For example in the case of nitrogen and carbon dioxide, in their pure state the separation factor is determined by diffusion, while in mixtures it is influenced more by adsorption in the membrane (zeolite in our case) Finally we developed a new technique using the NMR chemical shift to determine intermolecular interactions for mixtures. For polar-nonpolar systems such as Xe dissolved in water we were able to significantly improve the accuracy of gas solubilities, which are very sensitive to the cross interaction between water and Xe.

Sohail Murad

2012-01-03T23:59:59.000Z

476

9 - Microporous silica membranes: fundamentals and applications in membrane reactors for hydrogen separation  

Science Journals Connector (OSTI)

Abstract: This chapter discusses the research and development of membrane reactors, incorporating microporous silica-based membranes, specifically for hydrogen production. Microporous silica membranes are first introduced alongside a discussion of relevant gas transport mechanisms, membrane performance parameters, membrane reactor designs and membrane reactor performance metrics. This is followed by an in-depth analysis of the various research investigations where silica membrane reactors have been used to produce hydrogen and/or syngas from hydrocarbon reforming reactions. Of particular importance here is the hydrothermal instability of silica-based membranes at the required operating temperatures and so the chapter closes by presenting the future research trends and industrial design challenges and considerations of silica-based membrane reactors.

S. Smart; J. Beltramini; J.C. Diniz da Costa; S.P. Katikaneni; T. Pham

2013-01-01T23:59:59.000Z

477

Advanced membrane electrode assemblies for fuel cells  

DOE Patents (OSTI)

A method of preparing advanced membrane electrode assemblies (MEA) for use in fuel cells. A base polymer is selected for a base membrane. An electrode composition is selected to optimize properties exhibited by the membrane electrode assembly based on the selection of the base polymer. A property-tuning coating layer composition is selected based on compatibility with the base polymer and the electrode composition. A solvent is selected based on the interaction of the solvent with the base polymer and the property-tuning coating layer composition. The MEA is assembled by preparing the base membrane and then applying the property-tuning coating layer to form a composite membrane. Finally, a catalyst is applied to the composite membrane.

Kim, Yu Seung; Pivovar, Bryan S

2014-02-25T23:59:59.000Z

478

Industrial Plate Exchangers Heat Recovery and Fouling  

E-Print Network (OSTI)

by choosing a more suitable material of construction. Plate exchangers being economic on surface area are able to use materials such as stainless steels, titanium,hastelloy,incolloy etc.without excessive cost. Normally the more e~pensive the material... it to the plate exchanger which is easy to open and clean. During the late sixties the first plate heat exchangers were used for acid cooling direct. These had plates of Hastelloy C and gaskets of Viton rubber. These were generally restricted to an acid...

Cross, P. H.

1981-01-01T23:59:59.000Z