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Note: This page contains sample records for the topic "hydrofluorocarbons hfcs perfluorocarbons" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
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1

Atmospheric histories and global emissions of the anthropogenic hydrofluorocarbons HFC-365mfc, HFC-245fa, HFC-227ea, and HFC-236fa  

E-Print Network [OSTI]

We report on ground-based atmospheric measurements and emission estimates of the four anthropogenic hydrofluorocarbons (HFCs) HFC-365mfc (CH[subscript 3]CF[subscript 2]CH[subscript 2]CF[subscript 3], 1,1,1,3,3-pentafluorobutane), ...

Rigby, Matthew

2

The greenhouse gases HFCs, PFCs Danish consumption and emissions, 2007  

E-Print Network [OSTI]

The greenhouse gases HFCs, PFCs and SF6 Danish consumption and emissions, 2007 Tomas Sander Poulsen AND EMISSION OF F-GASES 7 1.1.1 Consumption 7 1.1.2 Emission 7 1.1.3 Trends in total GWP contribution from F 21 4 EMISSION OF F-GASES 23 4.1.1 Emissions of HFCs from refrigerants 23 4.1.2 Emissions of HFCs from

3

Perfluorocarbon tracer method for air-infiltration measurements  

DOE Patents [OSTI]

A method of measuring air infiltration rates suitable for use in rooms of homes and buildings comprises the steps of emitting perfluorocarbons in the room to be measured, sampling the air containing the emitted perfluorocarbons over a period of time, and analyzing the samples at a laboratory or other facility.

Dietz, R.N.

1982-09-23T23:59:59.000Z

4

Trends and inferred emissions of atmospheric high molecular weight perfluorocarbons  

E-Print Network [OSTI]

Atmospheric observations and atmospheric observation-based global emission estimates are presented for the five high molecular weight perfluorocarbons (PFCs): decafluorobutane (C 4 F 1 0 ), dodecafluoropentane (C5 F1 2 ), ...

Ivy, Diane Jean

2012-01-01T23:59:59.000Z

5

Perfluorocarbons in the global atmosphere: tetrafluoromethane, hexafluoroethane, and octafluoropropane  

E-Print Network [OSTI]

We present atmospheric baseline growth rates from the 1970s to the present for the long-lived, strongly infrared-absorbing perfluorocarbons (PFCs) tetrafluoromethane (CF4), hexafluoroethane (C2F6), and octafluoropropane ...

Muhle, J.

6

Method for enhancing microbial utilization rates of gases using perfluorocarbons  

DOE Patents [OSTI]

A method of enhancing the bacterial reduction of industrial gases using perfluorocarbons (PFCs) is disclosed. Because perfluorocarbons (PFCs) allow for a much greater solubility of gases than water does, PFCs have the potential to deliver gases in higher concentrations to microorganisms when used as an additive to microbial growth media thereby increasing the rate of the industrial gas conversion to economically viable chemicals and gases.

Turick, Charles E. (Idaho Falls, ID)

1997-01-01T23:59:59.000Z

7

Method for enhancing microbial utilization rates of gases using perfluorocarbons  

DOE Patents [OSTI]

A method of enhancing the bacterial reduction of industrial gases using perfluorocarbons (PFCs) is disclosed. Because perfluorocarbons (PFCs) allow for a much greater solubility of gases than water does, PFCs have the potential to deliver gases in higher concentrations to microorganisms when used as an additive to microbial growth media thereby increasing the rate of the industrial gas conversion to economically viable chemicals and gases. 3 figs.

Turick, C.E.

1997-06-10T23:59:59.000Z

8

Adsorption of Hydrofluorocarbons HFC-134 and HFC-134A on X and Y Zeolites: Effect of Ion-Exchange on Selectivity and Heat of Adsorption  

E-Print Network [OSTI]

rapidly as worldwide refrigerator and air-conditioner production rises almost exponentially.1 A byproduct) is a hydrofluorocarbon coolant for refrigerators designated to replace the ozone-damaging chloro- fluorocarbons (CFCs

Siperstein, Flor R.

9

QUANTIFICATION OF FUGITIVE REACTIVE ALKENE EMISSIONS FROM PETROCHEMICAL PLANTS WITH PERFLUOROCARBON TRACERS.  

SciTech Connect (OSTI)

Recent studies demonstrate the impact of fugitive emissions of reactive alkenes on the atmospheric chemistry of the Houston Texas metropolitan area (1). Petrochemical plants located in and around the Houston area emit atmospheric alkenes, such as ethene, propene and 1,3-butadiene. The magnitude of emissions is a major uncertainty in assessing their effects. Even though the petrochemical industry reports that fugitive emissions of alkenes have been reduced to less than 0.1% of daily production, recent measurement data, obtained during the TexAQS 2000 experiment indicates that emissions are perhaps a factor of ten larger than estimated values. Industry figures for fugitive emissions are based on adding up estimated emission factors for every component in the plant to give a total estimated emission from the entire facility. The dramatic difference between estimated and measured rates indicates either that calculating emission fluxes by summing estimates for individual components is seriously flawed, possibly due to individual components leaking well beyond their estimated tolerances, that not all sources of emissions for a facility are being considered in emissions estimates, or that there are known sources of emissions that are not being reported. This experiment was designed to confirm estimates of reactive alkene emissions derived from analysis of the TexAQS 2000 data by releasing perfluorocarbon tracers (PFTs) at a known flux from a petrochemical plant and sampling both the perfluorocarbon tracer and reactive alkenes downwind using the Piper-Aztec research aircraft operated by Baylor University. PFTs have been extensively used to determine leaks in pipelines, air infiltration in buildings, and to characterize the transport and dispersion of air parcels in the atmosphere. Over 20 years of development by the Tracer Technology Center (TTC) has produced a range of analysis instruments, field samplers and PFT release equipment that have been successfully deployed in a large variety of experiments. PFTs are inert, nontoxic, noncombustible and nonreactive. Up to seven unique PFTs can be simultaneously released, sampled and analyzed and the technology is well suited for determining emission fluxes from large petrochemical facilities. The PFT experiment described here was designed to quantitate alkene emissions from a single petrochemical facility, but such experiments could be applied to other industrial sources or groups of sources in the Houston area.

SENUM,G.I.; DIETZ,R.N.

2004-06-30T23:59:59.000Z

10

A Really Good Hammer: Quantification of Mass Transfer Using Perfluorocarbon Tracers (475th Brookhaven Lecture)  

SciTech Connect (OSTI)

Brookhaven Lab’s perfluorocarbon tracer (PFT) technology can be viewed as a hammer looking for nails. But, according to Tom Watson, leader of the Lab’s Tracer Technology Group in the Environmental Research and Technology Division (ERTD), “It’s a really good hammer!” The colorless, odorless and safe gases have a number of research uses, from modeling how airborne contaminants might move through urban canyons to help first responders plan their response to potential terrorist attacks and accidents to locating leaks in underground gas pipes. Their extremely low background level — detectable at one part per quadrillion — allows their transport to be easily tracked. Lab researchers used PFTs during the 2005 Urban Dispersion Program field studies in New York City, gathering data to help improve models of how a gas or chemical release might move around Manhattan’s tall buildings and canyons. Closer to home, scientists also used PFTs to make ventilation measurements in Bldg. 400 on the Lab site to provide data to test air flow models used in determining the effects of passive and active air exchange on the levels of indoor and outdoor air pollution, and to determine the effects of an accidental or intentional release of hazardous substances in or around buildings.

Watson, Tom [BNL Environmental Sciences, Tracer Technology Group

2012-02-15T23:59:59.000Z

11

Measurement of HVAC system performance and local ventilation using passive perfluorocarbon tracer technology  

SciTech Connect (OSTI)

In April of 1993, two (2) perfluorocarbon tracer (PFT) ventilation/indoor air quality assessment tests were performed in the Gleeson Hall building of the SUNY Farmingdale campus. The building was being modified, in part, as a result of significant occupant complaints of perceived poor air quality. The four story building had a basement first floor with air supplied normally by an HVAC system labelled as AC1. During this study, AC1 was inoperational and the basement interior rooms (walls) were primarily gone; the other three floors were still being used for classes. It is possible that a sense of poor air quality may have been perceived by first-floor occupants because they were working in the basement, but this issue could not be addressed. The second floor had two (2) lecture halls--Rm 202 (handled by AC4) and Rm 204 (handled by AC5); the balance of the second floor interior rooms and corridors was split between two other air handling systems, AC2 for the west side of the building and AC3 for the east side. The remaining 3rd and 4th floors were also split about evenly between AC2 and AC3. The perimeter rooms, equipped with wall units having their own outside air (OA) source plus centralized return air (RA) bypasses, were not included in this testing which was restricted to the basement floor (1st floor) and the four operating air handling systems, AC2 to AC5, during Test 1 and only AC2 to AC5 during Test 2. Two types of tests were performed using the full suite of 5 PFT types available. The first test was designed to measure the infiltration, exfiltration, and air exchange between the 5 AC zones above and the second test used the 5th tracer, which had been in the basement, as a distributed source throughout the four other zones to act as a surrogate pollutant source. This report provides final conclusions of both tests and suggestions regarding its usefulness in similar building ventilation and indoor air quality assessments.

Dietz, R.N.; Goodrich, R.W.

1995-06-01T23:59:59.000Z

12

USING PERFLUOROCARBON TRACERS FOR VERIFICATION OF CAP AND COVER SYSTEMS PERFORMANCE.  

SciTech Connect (OSTI)

The Department of Energy (DOE) Environmental Management (EM) office has committed itself to an accelerated cleanup of its national facilities. The goal is to have much of the DOE legacy waste sites remediated by 2006. This includes closure of several sites (e.g., Rocky Flats and Fernald). With the increased focus on accelerated cleanup, there has been considerable concern about long-term stewardship issues in general, and verification and long-term monitoring (LTM) of caps and covers, in particular. Cap and cover systems (covers) are vital remedial options that will be extensively used in meeting these 2006 cleanup goals. Every buried waste site within the DOE complex will require some form of cover system. These covers are expected to last from 100 to 1000 years or more. The stakeholders can be expected to focus on system durability and sustained performance. DOE EM has set up a national committee of experts to develop a long-term capping (LTC) guidance document. Covers are subject to subsidence, erosion, desiccation, animal intrusion, plant root infiltration, etc., all of which will affect the overall performance of the cover. Very little is available in terms of long-term monitoring other than downstream groundwater or surface water monitoring. By its very nature, this can only indicate that failure of the cover system has already occurred and contaminants have been transported away from the site. This is unacceptable. Methods that indicate early cover failure (prior to contaminant release) or predict approaching cover failure are needed. The LTC committee has identified predictive monitoring technologies as a high priority need for DOE, both for new covers as well as existing covers. The same committee identified a Brookhaven National Laboratory (BNL) technology as one approach that may be capable of meeting the requirements for LTM. The Environmental Research and Technology Division (ERTD) at BNL developed a novel methodology for verifying and monitoring subsurface barriers (1,2). The technology uses perfluorocarbon tracers (PFTs) to determine flaws (e.g., holes or cracks) and high permeability areas in subsurface barriers. Gaseous tracers are injected on one side of the barrier and searched for on the opposite side of the barrier. The sampling grid, concentration, and time of arrival of the tracer(s) on the opposite side are used to determine the size and location of flaws and relative permeability of the barrier. In addition, there are multiple tracers available, which allows different tracers to be injected in different quadrants of the barrier. This yields additional information on transport phenomena of the barrier.

HEISER,J.; SULLIVAN,T.

2001-11-01T23:59:59.000Z

13

Emissions of greenhouse gases in the United States 1995  

SciTech Connect (OSTI)

This is the fourth Energy Information Administration (EIA) annual report on US emissions of greenhouse gases. This report presents estimates of US anthropogenic (human-caused) emissions of carbon dioxide, methane, nitrous oxide, and several other greenhouse gases for 1988 through 1994. Estimates of 1995 carbon dioxide, nitrous oxide, and halocarbon emissions are also provided, although complete 1995 estimates for methane are not yet available. Emissions of carbon dioxide increased by 1.9% from 1993 to 1994 and by an additional 0.8% from 1994 to 1995. Most carbon dioxide emissions are caused by the burning of fossil fuels for energy consumption, which is strongly related to economic growth, energy prices, and weather. The US economy grew rapidly in 1994 and slowed in 1995. Estimated emissions of methane increased slightly in 1994, as a result of a rise in emissions from energy and agricultural sources. Estimated nitrous oxide emissions increased by 1.8% in 1995, primarily due to increased use of nitrogen fertilizers and higher output of chemicals linked to nitrous oxide emissions. Estimated emissions of hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs), which are known to contribute to global warming, increased by nearly 11% in 1995, primarily as a result of increasing substitution for chlorofluorocarbons (CFCs). With the exception of methane, the historical emissions estimates presented in this report are only slightly revised from those in last year`s report.

NONE

1996-10-01T23:59:59.000Z

14

THE BROOKHAVEN NATIONAL LABORATORY PERFLUOROCARBON TRACER TECHNOLOGY: A PROVEN AND COST EFFECTIVE METHOD TO VERIFY INTEGRITY AND MONITOR LONG TERM PERFORMANCE OF WALLS, FLOORS, CAPS, AND COVER SYSTEMS.  

SciTech Connect (OSTI)

Currently, containment system failures are detected by monitoring wells downstream of the waste site. Clearly this approach is inefficient, as the contaminants will have migrated from the disposal area before they are detected. Methods that indicate early cover failure (prior to contaminant release) or predict impending cover failure are needed. The Brookhaven National Laboratory (BNL) Perfluorocarbon Tracer (PFT) technology can measure performance changes and integrity losses as the cover ages. This allows early detection of cover failure or pending failure so that repair or replacement can be made before contaminants leave the disposal cell. The PFT technology has been successfully applied to four subsurface barrier problems, one leak detection problem from underground ducts, and one surface cover problem. Testing has demonstrated that the PFTs are capable of accurately detecting and locating leaks down to fractions of an inch. The PFT technology has several advantages over competing approaches. The ability to simultaneously use multiple PFTs separates it from other gas tracer technologies. Using multiple tracers provides independent confirmation of flaw location, helps to clearly define transport pathways, and can be used for confirmatory testing (e.g., repeat the test using a new tracer). The PFT tests provide a direct measure of flaws in a barrier, whereas other measurements (pressure, moisture content, temperature, subsidence) provide indirect measures that need interpretation. The focus of the six PFT demonstrations has been on engineering aspects of the technology with the intent of finding if a flaw existed in the barrier. Work remains to be done on the scientific basis for this technology. This includes determining PFT diffusion rates through various materials (soils and barrier) as a function of moisture content, determining the effects of barometric pumping on PFT flow for cover systems, and determining wind effects on side slopes of cover systems and their impact on PFT performance. It also includes application of models to assist in the design of the monitoring system and the interpretation of the data. The set of demonstrations was performed on small sites (< 1/4 acre). Future work also needs to consider scaling issues to develop and design optimal techniques for delivery and monitoring of the PFTs.

HEISER, J.; SULLIVAN, T.

2002-03-11T23:59:59.000Z

15

Greenhouse Gas Management Program Overview (Fact Sheet)  

SciTech Connect (OSTI)

Program fact sheet highlighting federal requirements for GHG emissions management, FEMP services to help agencies reduce emissions, and additional resources. The U.S. Department of Energy (DOE) Federal Energy Management Program (FEMP) assists Federal agencies with managing their greenhouse gas (GHG) emissions. GHG management entails measuring emissions and understanding their sources, setting a goal for reducing emissions, developing a plan to meet this goal, and implementing the plan to achieve reductions in emissions. FEMP provides the following services to help Federal agencies meet the requirements of inventorying and reducing their GHG emissions: (1) FEMP offers one-on-one technical assistance to help agencies understand and implement the Federal Greenhouse Gas Accounting and Reporting Guidance and fulfill their inventory reporting requirements. (2) FEMP provides training, tools, and resources on FedCenter to help agencies complete their annual inventories. (3) FEMP serves a leadership role in the interagency Federal Working Group on Greenhouse Gas Accounting and Reporting that develops recommendations to the Council on Environmental Quality (CEQ) for the Federal Greenhouse Gas Accounting and Reporting Guidance. (4) As the focus continues to shift from measuring emissions (completing inventories) to mitigating emissions (achieving reductions), FEMP is developing a strategic planning framework and resources for agencies to prioritize among a variety of options for mitigating their GHG emissions, so that they achieve their reduction goals in the most cost-effective manner. These resources will help agencies analyze their high-quality inventories to make strategic decisions about where to use limited resources to have the greatest impact on reducing emissions. Greenhouse gases trap heat in the lower atmosphere, warming the earth's surface temperature in a natural process known as the 'greenhouse effect.' GHGs include carbon dioxide (CO{sub 2}), methane (CH{sub 4}), nitrous oxide (N{sub 2}O), perfluorocarbons (PFCs), hydrofluorocarbons (HFCs), and sulfur hexafluoride (SF{sub 6}). Human activities have caused a rapid increase in GHG concentrations. This rising level contributes to global climate change, which contributes to environmental and public health problems.

Not Available

2011-11-01T23:59:59.000Z

16

Atmospheric and soil-gas monitoring for surface leakage at the San Juan Basin CO{sub 2} pilot test site at Pump Canyon New Mexico, using perfluorocarbon tracers, CO{sub 2} soil-gas flux and soil-gas hydrocarbons  

SciTech Connect (OSTI)

Near-surface monitoring and subsurface characterization activities were undertaken in collaboration with the Southwest Regional Carbon Sequestration Partnership on their San Juan Basin coal-bed methane pilot test site near Navajo City, New Mexico. Nearly 18,407 short tons (1.670 × 107 kg) of CO{sub 2} were injected into 3 seams of the Fruitland coal between July 2008 and April 2009. Between September 18 and October 30, 2008, two additions of approximately 20 L each of perfluorocarbon (PFC) tracers were mixed with the CO{sub 2} at the injection wellhead. PFC tracers in soil-gas and in the atmosphere were monitored over a period of 2 years using a rectangular array of permanent installations. Additional monitors were placed near existing well bores and at other locations of potential leakage identified during the pre-injection site survey. Monitoring was conducted using sorbent containing tubes to collect any released PFC tracer from soil-gas or the atmosphere. Near-surface monitoring activities also included CO{sub 2} surface flux and carbon isotopes, soil-gas hydrocarbon levels, and electrical conductivity in the soil. The value of the PFC tracers was demonstrated when a significant leakage event was detected near an offset production well. Subsurface characterization activities, including 3D seismic interpretation and attribute analysis, were conducted to evaluate reservoir integrity and the potential that leakage of injected CO{sub 2} might occur. Leakage from the injection reservoir was not detected. PFC tracers made breakthroughs at 2 of 3 offset wells which were not otherwise directly observable in produced gases containing 20–30% CO{sub 2}. These results have aided reservoir geophysical and simulation investigations to track the underground movement of CO{sub 2}. 3D seismic analysis provided a possible interpretation for the order of appearance of tracers at production wells.

Wells, Arthur W.; Diehl, J. Rodney; Strazisar, Brian R.; Wilson, Thomas; H Stanko, Dennis C.

2012-05-01T23:59:59.000Z

17

Novel hydrofluorocarbon polymers for use as pellicles in 157 nm semiconductor photolithography: fundamentals of transparency  

E-Print Network [OSTI]

Pont Photomasks Inc., 4 Finance Dr., Danbury, CT 06810, USA c INEOS, Russian Academy of Sciences, Vavilova 28

Rollins, Andrew M.

18

Trends and Inferred Emissions of Atmospheric High Molecular Weight Perfluorocarbons  

E-Print Network [OSTI]

) and octadecafluorooctane (C8F18). Their atmospheric histories are based on measurements of 36 Northern Hemisphere and 468F18. Based on our observations, the 2011 globally averaged dry air mole fractions of these high12, 0.27 ppt for C6F14, 0.12 ppt for C7F16 and 0.09 ppt for C8F18. Newly measured infrared absorption

19

Synopsis of residential refrigerator/freezer alternative refrigerants evaluation  

SciTech Connect (OSTI)

The experimental testing on residential refrigerator/freezers (R/Fs) is summarized in this paper. R/F testing focused on two areas: alternative refrigerants and equipment configurations. The refrigerants evaluated consisted of single components, azeotropes, and zeotropes derived from hydrofluorocarbons (HFCs) and hydrocarbons (HCs). These refrigerants were evaluated in conventional and unconventional R/F designs. Major and minor design modifications were studied. Minor modifications consisted of various capillary tube lengths, door insulations, and compressors, while major modifications included two-evaporator and two-cycle R/F systems. Results obtained from testing the two-cycle system will be discussed in a later paper. This paper presents the experimental results of alternative technologies evaluated as replacements for ozone depleting chemicals.

Baskin, E. [Environmental Protection Agency, Research Triangle Park, NC (United States)

1998-12-31T23:59:59.000Z

20

Laboratory testing and modeling to evaluate perfluorocarbon compounds as tracers in geothermal systems  

SciTech Connect (OSTI)

The thermal stability and adsorption characteristics of three perfluorinated hydrocarbon compounds were evaluated under geothermal conditions to determine the potential to use these compounds as conservative or thermally-degrading tracers in Engineered (or Enhanced) Geothermal Systems (EGS). The three compounds tested were perfluorodimethyl-cyclobutane (PDCB), perfluoromethylcyclohexane (PMCH), and perfluorotrimethylcyclohexane (PTCH), which are collectively referred to as perfluorinated tracers, or PFTs. Two sets of duplicate tests were conducted in batch mode in gold-bag reactors, with one pair of reactors charged with a synthetic geothermal brine containing the PFTs and a second pair was charged with the brine-PFT mixture plus a mineral assemblage chosen to be representative of activated fractures in an EGS reservoir. A fifth reactor was charged with deionized water containing the three PFTs. The experiments were conducted at {approx}100 bar, with temperatures ranging from 230 C to 300 C. Semi-analytical and numerical modeling was also conducted to show how the PFTs could be used in conjunction with other tracers to interrogate surface area to volume ratios and temperature profiles in EGS reservoirs. Both single-well and cross-hole tracer tests are simulated to illustrate how different suites of tracers could be used to accomplish these objectives. The single-well tests are especially attractive for EGS applications because they allow the effectiveness of a stimulation to be evaluated without drilling a second well.

Reimus, Paul W [Los Alamos National Laboratory

2011-01-21T23:59:59.000Z

Note: This page contains sample records for the topic "hydrofluorocarbons hfcs perfluorocarbons" 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

Demonstration of High Efficiency Elastocaloric Cooling with Large Delta- T Using NiTi Wires  

SciTech Connect (OSTI)

Vapor compression (VC) is by far the most dominant technology for meeting all cooling and refrigeration needs around the world. It is a mature technology with the efficiency of modern compressors approaching the theoretical limit, but its envi-ronmental footprint remains a global problem. VC refrigerants such as hydrochlo-roflurocarbons (HCFCs) and hydrofluorocarbons (HFCs) are a significant source of green house gas (GHG) emissions, and their global warming potential (GWP) is as high as 1000 times that of CO2. It is expected that building space cooling and re-frigeration alone will amount to {approx} 5% of primary energy consumption and {approx}5% of all CO2 emission in U.S. in 2030 . As such, there is an urgent need to develop an al-ternative high-efficiency cooling technology that is affordable and environmentally friendly. Among the proposed candidates, magnetocaloric cooling (MC) is currently received a lot of attention because of its high efficiency. However, MC is inherently expensive because of the requirement of large magnetic field and rare earth materi-als. Here, we demonstrate an entirely new type of solid-state cooling mechanism based on the latent heat of reversible martensitic transformation. We call it elasto-caloric cooling (EC) after the superelastic transformation of austenite it utilizes. The solid-state refrigerant of EC is cost-effective, and it completely eliminates the use of any refrigerants including HCFCs/HFCs. We show that the COP (coefficient of per-formance) of a jugular EC with optimized materials can be as high as > 10 with measured {Delta}T of 17 C.

Cui, Jun; Wu, Yiming; Muehlbauer, Jan; Hwang, Yunho; Radermacher, Reinhard; Fackler, Sean; Wuttig, Manfred; Takeuchi, Ichiro

2012-08-01T23:59:59.000Z

22

Energy and global warming impacts of HFC refrigerants and emerging technologies: TEWI-III  

SciTech Connect (OSTI)

The use of hydrofluorocarbons (BFCs) which were developed as alternative refrigerants and insulating foam blowing agents to replace chlorofluorocarbons (CFCs) is now being affected by scientific investigations of greenhouse warming and questions about the effects of refrigerants and blowing agents on global warming. A Total Equivalent Warming Impact (TEWI) assessment analyzes the environmental affects of these halogenated working fluids in energy consuming applications by combining a direct effect resulting from the inadvertent release of HFCs to the atmosphere with an indirect effect resulting from the combustion of fossil fuels needed to provide the energy to operate equipment using these compounds as working fluids. TEWI is a more balanced measure of environmental impact because it is not based solely on the global warming potential (GWP) of the working fluid. It also shows the environmental benefit of efficient technologies that result in less CO{sub 2} generation and eventual emission to the earth`s atmosphere. The goal of TEWI is to assess total global warming impact of all the gases released to the atmosphere, including CO{sub 2} emissions from energy conversion. Alternative chemicals and technologies have been proposed as substitutes for HFCs in the vapor-compression cycle for refrigeration and air conditioning and for polymer foams in appliance and building insulations which claim substantial environmental benefits. Among these alternatives are: (1) Hydrocarbon (HC) refrigerants and blowing agents which have zero ozone depleting potential and a negligible global warming potential, (2) CO{sub 2} as a refrigerant and blowing agent, (3) Ammonia (NH{sub 3}) vapor compression systems, (4) Absorption chiller and heat pumping cycles using ammonia/water or lithium bromide/water, and (5) Evacuated panel insulations. This paper summarizes major results and conclusions of the detailed final report on the TEWI-111 study.

Sand, J.R.; Fischer, S.K.; Baxter, V.D.

1997-06-01T23:59:59.000Z

23

Energy and global warming impacts of next generation refrigeration and air conditioning technologies  

SciTech Connect (OSTI)

Significant developments have occurred in hydrofluorocarbon (HFC) and the application of ammonia and hydrocarbons as refrigerant working fluids since the original TEWI (Total Equivalent Warming Impact) report in 1991. System operating and performance data on alternative refrigerants and refrigeration technologies justify and updated evaluation of these new alternative refrigerants and competing technologies in well-characterized applications. Analytical and experimental results are used to show quantitative comparisons between HFCS, HFC blends, hydrocarbons, and ammonia, used as refrigerants. An objective evaluation is presented for commercial and near commercial non-CFC refrigerants/blowing agents and alternative refrigeration technologies. This information is needed for objective and quantitative decisions on policies addressing greenhouse gas emissions from refrigeration and air conditioning equipment. The evaluation assesses the energy use and global warming impacts of refrigeration and air conditioning technologies that could be commercialized during the phase out of HCFCS. Quantitative comparison TEWI for two application areas are presented. Opportunities for significant reductions in TEWI are seen with currently known refrigerants through improved maintenance and servicing practices and improved product designs.

Sand, J.R.; Fischer, S.K.; Baxter, V.D.

1996-10-01T23:59:59.000Z

24

Feasibility of a Perfluorocarbon tracer based network to support Monitoring, Verification, and Accounting of Sequestered CO2  

E-Print Network [OSTI]

, and Accounting of Sequestered CO2 Thomas B. Watson* and Terrence Sullivan Brookhaven National Laboratory, Upton% of total sequestered CO2 over the lifetime of the reservoir. This is 0.001% per year for a 1000 year lifetime of a storage reservoir. Effective detection of CO2 leaks at the surface may require incorporation

Johnson, Peter D.

25

E-Print Network 3.0 - absorber gadolinum comparative Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Fluoropolymer; Hydrofluorocarbon; 157 nm; Photolithography; Optical absorbance Source: French, Roger H. - Department of Materials Science and Engineering, University of...

26

TEWI Analysis: Its Utility, Its Shortcomings, and Its Results  

SciTech Connect (OSTI)

The past decade has been a challenging time for the refrigeration and air conditioning industry worldwide. Provisions of the Montreal Protocol and its amendments require the phaseout of chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) compounds that have been used extensively as insulating foam blowing agents and refrigerants in refrigeration systems, heat pumps, and air conditioners. In response, hydrofluorocarbon (HFC) compounds were proposed, developed, and are starting to be used as the primary alternatives to CFCs and HCFCs. However, in 1997 under the Kyoto Protocol, industrialized nations have agreed to roll back emissions of HCFCs, carbon dioxide (CO*), and four other greenhouse gases which threaten to cause excessive global warming. The US. Department of Energy and the Alternative Fluorocarbon Environmental Acceptability Study (AFEAS) jointly sponsored research projects to identify the major applications of CFCs, HCFCs, and HFCs and to examine the impacts of these compounds and the energy use of applications employing these compounds on global warming. The five major uses of fluorocarbons based on sales were automobile air conditioning, supermarket refrigeration, unitary heat pumps and air conditioning, chillers for cooling large office buildings, and household refrigeration. Almost all of the refrigerants used in these applications are global warming gases, and if the refrigerant leaks out of the system during operation, is lost during maintenance or is not recovered when the system is scraped, it contributes to global warming. But, it is also true that the energy consumed by refrigeration and air conditioning systems, in the form of electricity or the direct combustion of fossil fuel, results in the release of CO*, the primary cause of atmospheric global warming.

Baxter, V.D.; Fischer, S.K.; Sand, J.R.

1999-09-13T23:59:59.000Z

27

Global warming impacts of ozone-safe refrigerants and refrigeration, heating, and air-conditioning technologies  

SciTech Connect (OSTI)

International agreements mandate the phase-out of many chlorine containing compounds that are used as the working fluid in refrigeration, air-conditioning, and heating equipment. Many of the chemical compounds that have been proposed, and are being used in place of the class of refrigerants eliminated by the Montreal Protocol are now being questioned because of their possible contributions to global warming. Natural refrigerants are put forth as inherently superior to manufactured refrigerants because they have very low or zero global warming potentials (GWPs). Questions are being raised about whether or not these manufactured refrigerants, primarily hydrofluorocarbons (HFCs), should be regulated and perhaps phased out in much the same manner as CFCs and HCFCs. Several of the major applications of refrigerants are examined in this paper and the results of an analysis of their contributions to greenhouse warming are presented. Supermarket refrigeration is shown to be an application where alternative technologies have the potential to reduce emissions of greenhouse gases (GHG) significantly with no clear advantage to either natural or HFC refrigerants. Mixed results are presented for automobile air conditioners with opportunities to reduce GHG emissions dependent on climate and comfort criteria. GHG emissions for hermetic and factory built systems (i.e. household refrigerators/freezers, unitary equipment, chillers) are shown to be dominated by energy use with much greater potential for reduction through efficiency improvements than by selection of refrigerant. The results for refrigerators also illustrate that hydrocarbon and carbon dioxide blown foam insulation have lower overall effects on GHG emissions than HFC blown foams at the cost of increased energy use.

Fischer, S.; Sand, J.; Baxter, V.

1997-12-01T23:59:59.000Z

28

The Climate Change Action Plan: Technical supplement  

SciTech Connect (OSTI)

This Technical Annex documents the assumptions and parameters used in developing the supporting analysis for the Climate Change Action Plan (the Plan) issued by President Clinton on October 19, 1993. The Annex is intended to meet the needs of independent energy and environmental analysts who wish to better understand the Plan, its analytical underpinnings, and the events that need to transpire for the emissions reductions called for in the Plan to be realized. The Plan documented in this Annex reflects the outcome of a wide-ranging effort by Government agencies and interested members of the public to develop and implement actions that can reduce net greenhouse gas emissions in the year 2000 to their aggregate 1990 level. Based on agency and public input, the Climate Change Mitigation Group, chaired by the White House Office on Environmental Policy, developed the Plan`s content. Many of the actions called for in the Plan are now underway, while others are in advanced planning pending congressional action on the fiscal year 1995 budget. The analysis supporting the Plan represents the results of an interagency effort. The US Department of Energy (DOE) was responsible for the integrated analysis of energy-related options, based on the analysis of individual energy-related options by DOE, the US Environmental Protection Agency (EPA), and the US Department of Transportation (DOT). EPA led in providing analysis for actions related to methane, hydrofluorocarbons, and perfluorocarbons. The US Department of Agriculture (USDA) led the analysis of carbon sequestration actions and cooperated with EPA in the analysis of actions to reduce nitrous oxide emissions.

Not Available

1994-03-01T23:59:59.000Z

29

Millenium Science Complex New clean room: 10,000 sq. ft. class 100/1000  

E-Print Network [OSTI]

-ring outgassing · All high temperature O-rings made of fluorocarbon or perfluorocarbon materials have this issue

30

Molecular Design Using Quantum Chemical Calculations for Property Estimation  

E-Print Network [OSTI]

techniques for molecular design. A simple hydrofluorocarbon refrigerant design example and a solvent design level information about any system can be predicted (e.g., molecular energies, electronic charge as the target property, motivated by an interest in chemically stable hydrofluorocarbon refrigerants. The second

Maranas, Costas

31

E-Print Network 3.0 - alkenes Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

was performed under the auspices of the U.S. Department Summary: ALKENE EMISSIONS FROM PETROCHEMICAL PLANTS WITH PERFLUOROCARBON TRACERS Gunnar I. Senum and Russell N... of...

32

BNL-73106-2004-IR Research by BNL investigators was performed under the auspices of the U.S. Department  

E-Print Network [OSTI]

ALKENE EMISSIONS FROM PETROCHEMICAL PLANTS WITH PERFLUOROCARBON TRACERS Gunnar I. Senum and Russell N (1). Petrochemical plants located in and around the Houston area emit atmospheric alkenes by releasing perfluorocarbon tracers (PFTs) at a known flux from a petrochemical plant and sampling both

33

Reliability of Heat Pumps Containing R410-A Refrigerant  

E-Print Network [OSTI]

on alternate refrigerants. One major manufacturer announced a formation of black smudge on internal surfaces of field trial units using HFCs. Several causes were suggested but none were published. Reports of capillary tube plugging were wide spread. Polyol...

McJimsey, B. A.; Cawley, D.

1998-01-01T23:59:59.000Z

34

A Comparison of Fault Detection Methods For a Transcritical Refrigeration System  

E-Print Network [OSTI]

on Climate Change, eleven of the twelve years between 1995 and 2006 ranked with the highest temperatures since direct measurement has been available [3]. The use of hydroflourocarbons (HFCs) as refrigerants contributes to climate change. Global warming...

Janecke, Alex Karl

2012-10-19T23:59:59.000Z

35

Wind Power and the Clean Development Mechanism  

E-Print Network [OSTI]

Biogas Cement HFCs Geothermal EE Households Solar N2O Fugitive Tidal EE Service Transport Energy distrib 200 300 400 500 600 700 Lara Landfill (10 MW) Korat Biogas (3 MW) Rukmani Rice Husk (10 MW) Palestina

36

The State of the CDM & its Contribution to SD  

E-Print Network [OSTI]

distribution of CDM projects 2012 CER Total in the CDM Pipeline kCERs Population per cap. Latin America 609 23 category Renewables 61% Demand-side EE 5% Supply-side EE 11% Fuel sw itch 3% HFCs, PFCs & N2O reduction 2% Supply-side EE 10% CH4 reduction & Cement & Coal mine/bed 20% Renewables 28% HFCs, PFCs & N2O reduction

37

Global emission estimates and radiative impact of C[subscript 4]F[subscript 10], C[subscript 5]F[subscript 12], C[subscript 6]F[subscript 14], C[subscript 7]F[subscript 16] and C[subscript 8]F[subscript 18  

E-Print Network [OSTI]

Global emission estimates based on new atmospheric observations are presented for the acylic high molecular weight perfluorocarbons (PFCs): decafluorobutane (C[subscript 4]F[subscript 10]), dodecafluoropentane (C[subscript ...

Ivy, Diane J.

38

Infrared absorption spectra, radiative efficiencies, and global warming potentials  

E-Print Network [OSTI]

Infrared absorption spectra, radiative efficiencies, and global warming potentials absorption spectra, radiative efficiencies, and global warming potentials of perfluorocarbons: Comparison. (1995) and combined with atmospheric lifetimes from the literature to determine global warming

Wirosoetisno, Djoko

39

Primary aluminum production : climate policy, emissions and costs  

E-Print Network [OSTI]

Climate policy regarding perfluorocarbons (PFCs) may have a significant influence on investment decisions in the production of primary aluminum. This work demonstrates an integrated analysis of the effectiveness and likely ...

Harnisch, Jochen.; Sue Wing, Ian.; Jacoby, Henry D.; Prinn, Ronald G.

40

Update in Fluoroelastomers : fromPerfluoroelastomers to Fluorosilicones and Fluorophosphazenes  

E-Print Network [OSTI]

of the fluoroelastomers, ranging from (per)fluorocarbon elastomers to fluorophosphazenes, and fluorosilicones. 2 to be crosslinked and those are do not 2-1 Fluorocarbon elastomers. Usually, fluorocarbon elastomers are synthesised

Boyer, Edmond

Note: This page contains sample records for the topic "hydrofluorocarbons hfcs perfluorocarbons" 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

Enhanced naphthenic refrigeration oils for household refrigerator systems  

SciTech Connect (OSTI)

Due to industry concerns about the successful employment of hydrofluorocarbon-immiscible hydrocarbon oils in refrigeration systems, enhanced naphthenic refrigeration oils have been developed. These products have been designed to be more dispersible with hydrofluorocarbon (HFC) refrigerants, such as R-134a, in order to facilitate lubricant return to the compressor and to ensure proper energy efficiency of the system. Bench tests and system performance evaluations indicate the feasibility of these oils for use in household refrigeration applications. Results of these evaluations are compared with those obtained with polyol esters and typical naphthenic mineral oils employed in chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) refrigeration applications.

Reyes-Gavilan, J.L.; Flak, G.T.; Tritcak, T.R. [Witco Corp., Oakland, NJ (United States); Barbour, C.B. [Americold, Cullman, AL (United States)

1997-12-31T23:59:59.000Z

42

Environmental Data Sheet ENVIRONMENTAL DATA SHEET Dell Inc.  

E-Print Network [OSTI]

, the customer should not rely upon this information in making decisions about electrical tolerances or otherwise) other than in cables and interconnect parts · CFCs (chlorofluorocarbons), HCFCs (hydrofluorocarbons in the Montreal Protocol annex A, B, or C is used in Dell's manufacturing plants. Additional Materials Information

Fiebig, Peter

43

INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES The French APACHE project aims at  

E-Print Network [OSTI]

commercially available fuel cell vehicles [1­4]. Several projects of fuel cell aircrafts intend to demonstrate at demonstrating the feasibility of using a Hybrid Fuel Cell System (HFCS) as the power generator for all electric Fuel Cells (PEMFC), their hybridization with Lithium Ion (Li-Ion) batteries and systems' integration

Paris-Sud XI, Université de

44

Transportation and Greenhouse Gas Emissions: Measurement, Causation and Mitigation  

E-Print Network [OSTI]

.S. CO2 emissions sources. U.S. CO2 transportation emissions sources by mode. #12;Center% of the carbon dioxide we produce. As such it is a leading candidate for greenhouse gas ((GHG) (CO2, NH4, HFCsTransportation and Greenhouse Gas Emissions: Measurement, Causation and Mitigation Oak Ridge

45

Fracture Model, Ground Displacements and Tracer Observations: Fruitland Coals, San Juan Basin, New Mexico,  

E-Print Network [OSTI]

that the coal reservoirs consist of six separate coal beds rather than three. Perfluorocarbon tracer monitoring the site consist of two coal beds, each separated by a shale parting. This observation indicates will improve our understanding of Fruitland coal reservoirs; help develop more effective strategies to enhance

Wilson, Thomas H.

46

NOAA ARL Monthly Activity Report January 2005  

E-Print Network [OSTI]

. SURFRAD/ISIS 9. DHS Model Evaluation Planning 10. U.S. Climate Reference 11. Community Multiscale Air. Tracer Analysis Facility (TAF) Adaptation for Perfluorocarbon Tracer Analysis 19. Smart Balloon" Method for DCNet added to READY. A routine that inserts DCNet tower observations into the Eta gridded

47

Environment International, Vol. 8, pp. 419-433, 1982 0160-4120/82/070419-15503.00/0 Printed in the USA. All rights reserved. Copyright 1982 Pergamon Press Ltd.  

E-Print Network [OSTI]

perfluorocarbon tracer (PFT) sources and miniature passive samplers, both about the size of a cigarette, tests of passive adsorption tube samplers performed reproducibly and identically (to within + 2%-3%) in laboratory-story house. Multiple location sampling, as well as sampling in rooms with and without a miniature source

48

Evaluation of performance and composition shift of zeotropic mixtures in a Lorenz-Meutzner refrigerator/freezer  

SciTech Connect (OSTI)

Results from previous testing of this refrigerator/freezer using a 750 Btu/h compressor and several zeotropic mixtures revealed a performance enhancement up to 16% above that of hydrofluorocarbon R-134a. In the study presented in this paper, the Lorenz-Meutzner (LM) refrigerator/freezer equipped with a 1060 Btu/h compressor, two evaporators, and two intercoolers was experimentally tested in an environmental chamber according to the Association of Home Appliance Manufacturers/Department of Energy (AHAM/DOE) testing standards using several hydrofluoropropane-based zeotropic mixtures. The results are compared to baseline testing with R-134a and results obtained using the 750 Btu/h compressor. Hydrofluorocarbons R-245ca/R-152a performed comparably to R-134a. R-245ca/hydrocarbon R-270 (cyclopropane C{sub 3}H{sub 6}) outperformed all zeotropic mixtures and R-134a by at least 12.2 {+-} 0.7%. All refrigerants performed better using the larger compressor due to its inherently better efficiency. Refrigerant samples taken during refrigerator/freezer operation revealed substantial composition shifts (e.g., a 30% running composition shift of R-134a in the R-245ca/R-134a mixture). Sand et al. (1993) obtained an approximately 20% energy reduction using steady-state on-cycle energy consumption results; a comparison was made between chlorofluorocarbon R-12 and a hydrofluorocarbon R-32/hydrochlorofluorocarbon R-124 mixture. Lorenz and Meutzner (1975), originators of the Lorenz-Meutzner refrigerator/freezer design, state that the following parameters influence the optimum performance of the design: (1) heat exchanger size, (2) capillary tube length, (3) refrigerant charge, and (4) compressor size. This work investigates three of these parameters--capillary tube length, compressor size, and refrigerant charge.

Baskin, E.; Smith, N.D.; Delafield, F.R.; Tufts, M.W.

1999-07-01T23:59:59.000Z

49

Empirical correlations for the modeling of R-134a flow through adiabatic capillary tubes  

SciTech Connect (OSTI)

This paper presents the results of an experimental study on capillary tubes commonly used as an expansion device in household refrigerators and freezers. The experiments were performed with the hydrofluorocarbon R-134a at different condensing pressures and levels of subcooling. The pressure and temperature profiles along the capillary tubes were measured in each test run. The data set was then used to evaluate the suitability of some equations previously reported in the literature for the single-phase friction factor, the underpressure of vaporization, and the entrance contraction loss factor. Correlations for the average and local two-phase friction factors were also developed based on the measured data.

Melo, C.; Neto, C.B.; Silva Ferreira, R.T. da

1999-07-01T23:59:59.000Z

50

Chemical and thermal stability of refrigerant-lubricant mixtures with metals  

SciTech Connect (OSTI)

This report presents the results of a sealed tube stability study on twenty-one refrigerant-lubricant mixtures selected from the following groupings: HFCs R-32, R-125, R-134, R-134a, R-143a, and R-152a with one or more lubricants selected from among three pentaerythritol esters and three polyalkylene glycols. All lubricants were carefully predried to 25 ppm or less moisture content. HCFCs R-22, R-123, R-124, and R-142b, as well as CFC R-11, with one or more lubricants selected from among two mineral oils and one alkylbenzene fluid. Bach test mixture was aged at three temperature levels.

Huttenlocher, D.F.

1992-10-09T23:59:59.000Z

51

Chemical and thermal stability of refrigerant-lubricant mixtures with metals. Final report  

SciTech Connect (OSTI)

This report presents the results of a sealed tube stability study on twenty-one refrigerant-lubricant mixtures selected from the following groupings: HFCs R-32, R-125, R-134, R-134a, R-143a, and R-152a with one or more lubricants selected from among three pentaerythritol esters and three polyalkylene glycols. All lubricants were carefully predried to 25 ppm or less moisture content. HCFCs R-22, R-123, R-124, and R-142b, as well as CFC R-11, with one or more lubricants selected from among two mineral oils and one alkylbenzene fluid. Bach test mixture was aged at three temperature levels.

Huttenlocher, D.F.

1992-10-09T23:59:59.000Z

52

FINAL REPORT: EDDY-COVARIANCE FLUX TOWER AND TRACER TECHNOLOGY SUPPORT FOR THE UNIVERSITY OF GEORGIA PROPOSAL: FROM TOWER TO PIXEL: INTEGRATION OF PATCH-SIZE NEE USING EXPERIMENTAL MODELING FOOTPRINT ANALYSIS.  

SciTech Connect (OSTI)

Brookhaven National Laboratory has been funded since October of 2000 to provide assistance to the University of Georgia in conducting footprint analyses of individual towers based on meteorology and trace gas measurements. Brookhaven researchers conducted air flow measurements using perfluorocarbon tracers and meteorological instrumentation for three experimental campaigns at an AmeriFlux research site maintained by Dr. Monique Leclerc near Gainesville, FL. In addition, BNL provided assistance with remote data collection and distribution from remote field sites operated by Dr. John Hom of the US Forest Service in the Pine Barrens of New Jersey and at FACE research sites in North Carolina and Wisconsin.

LEWIN,K.F.; NAGY, J.; WATSON, T.B.

2007-09-01T23:59:59.000Z

53

Method for inducing hypothermia  

DOE Patents [OSTI]

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Becker, Lance B. (Chicago, IL); Hoek, Terry Vanden (Chicago, IL); Kasza, Kenneth E. (Palos Park, IL)

2008-09-09T23:59:59.000Z

54

Method for inducing hypothermia  

DOE Patents [OSTI]

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Becker, Lance B. (Chicago, IL); Hoek, Terry Vanden (Chicago, IL); Kasza, Kenneth E. (Palos Park, IL)

2003-04-15T23:59:59.000Z

55

Method for inducing hypothermia  

DOE Patents [OSTI]

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Becker, Lance B.; Hoek, Terry Vanden; Kasza, Kenneth E.

2005-11-08T23:59:59.000Z

56

Reducing the Carbon Footprint of Commercial Refrigeration Systems Using Life Cycle Climate Performance Analysis: From System Design to Refrigerant Options  

SciTech Connect (OSTI)

In this paper, Life Cycle Climate Performance (LCCP) analysis is used to estimate lifetime direct and indirect carbon dioxide equivalent gas emissions of various refrigerant options and commercial refrigeration system designs, including the multiplex DX system with various hydrofluorocarbon (HFC) refrigerants, the HFC/R744 cascade system incorporating a medium-temperature R744 secondary loop, and the transcritical R744 booster system. The results of the LCCP analysis are presented, including the direct and indirect carbon dioxide equivalent emissions for each refrigeration system and refrigerant option. Based on the results of the LCCP analysis, recommendations are given for the selection of low GWP replacement refrigerants for use in existing commercial refrigeration systems, as well as for the selection of commercial refrigeration system designs with low carbon dioxide equivalent emissions, suitable for new installations.

Fricke, Brian A [ORNL] [ORNL; Abdelaziz, Omar [ORNL] [ORNL; Vineyard, Edward Allan [ORNL] [ORNL

2013-01-01T23:59:59.000Z

57

Lubricant return comparison of naphthenic and polyol ester oils in R-134a household refrigeration applications  

SciTech Connect (OSTI)

This paper presents mineral oils and polyol esters as possible lubricant options for domestic refrigeration applications employing R-134a as the heat exchange fluid. A performance comparison, based on data presented, is made between the mineral oils and polyol esters evaluated. To more closely examine lubricant return with N-70 and R-134a and ensure that the oil is not contributing to any deterioration in efficiency due to its accumulation in evaporators, a special test unit was designed with a difficult oil return configuration and its performance carefully monitored. Oil return with a hydrofluorocarbon-miscible polyol ester, R-133-O was also evaluated in this setup and its performance results compared to those obtained with the naphthenic refrigeration oil.

Reyes-Gavilan, J.L.; Flak, G.T.; Tritcak, T.R. [Witco Corp., Oakland, NJ (United States)

1996-12-31T23:59:59.000Z

58

Measurement of large strains in ropes using plastic optical fibers  

DOE Patents [OSTI]

A method for the direct measurement of large strains in ropes in situ using a plastic optical fiber, for example, perfluorocarbon or polymethyl methacrylate and Optical Time-Domain Reflectometer or other light time-of-flight measurement instrumentation. Protective sheaths and guides are incorporated to protect the plastic optical fiber. In one embodiment, a small rope is braided around the plastic optical fiber to impose lateral compressive forces to restrain the plastic optical fiber from slipping and thus experience the same strain as the rope. Methods are described for making reflective interfaces along the length of the plastic optical fiber and to provide the capability to measure strain within discrete segments of the rope. Interpretation of the data allows one to calculate the accumulated strain at any point in time and to determine if the rope has experienced local damage.

Williams, Jerry Gene; Smith, David Barton; Muhs, Jeffrey David

2006-02-14T23:59:59.000Z

59

Delocalization and hybridization enhance the magnetocaloric effect in Ni2Mn0.75Cu0.25Ga  

SciTech Connect (OSTI)

In view of the looming energy crisis facing our planet, attention increasingly focuses on materials potentially useful as a basis for energy saving technologies. The discovery of giant magnetocaloric (GMC) compounds - materials that exhibit especially large changes in temperature as the externally applied magnetic field is varied - is one such compound 1. These materials have potential for use in solid state cooling technology as a viable alternative to existing gas based refrigeration technologies that use choro-fluoro - and hydro-fluoro-carbon chemicals known to have a severe detrimental effect on human health and environment 2,3. Examples of GMC compounds include Gd5(SiGe)4 4, MnFeP1-xAsx 5 and Ni-Mn-Ga shape memory alloy based compounds 6-8. Here we explain how the properties of one of these compounds (Ni2MnGa) can be tuned as a function of temperature by adding dopants. By altering the free energy such that the structural and magnetic transitions coincide, a GMC compound that operates at just the right temperature for human requirements can be obtained 9. We show how Cu, substituted for Mn, pulls the magnetic transition downwards in temperature and also, counterintuitively, increases the delocalization of the Mn magnetism. At the same time, this reinforces the Ni-Ga chemical bond, raising the temperature of the martensite-austenite transition. At 25percent doping, the two transitions coincide at 317 K.

Roy, Sujoy; Blackburn, E.; Valvidares, S. M.; Fitzsimmons, M. R.; Vogel, Sven C.; Khan, M.; Dubenko, I.; Stadler, S.; Ali, N.; Sinha, S. K.; Kortright, J. B.

2008-11-26T23:59:59.000Z

60

Passive Two-Phase Cooling of Automotive Power Electronics: Preprint  

SciTech Connect (OSTI)

Experiments were conducted to evaluate the use of a passive two-phase cooling strategy as a means of cooling automotive power electronics. The proposed cooling approach utilizes an indirect cooling configuration to alleviate some reliability concerns and to allow the use of conventional power modules. An inverter-scale proof-of-concept cooling system was fabricated, and tests were conducted using the refrigerants hydrofluoroolefin HFO-1234yf and hydrofluorocarbon HFC-245fa. Results demonstrated that the system can dissipate at least 3.5 kW of heat with 250 cm3 of HFC-245fa. An advanced evaporator design that incorporates features to improve performance and reduce size was conceived. Simulation results indicate its thermal resistance can be 37% to 48% lower than automotive dual side cooled power modules. Tests were also conducted to measure the thermal performance of two air-cooled condensers--plain and rifled finned tube designs. The results combined with some analysis were then used to estimate the required condenser size per operating conditions and maximum allowable system (i.e., vapor and liquid) temperatures.

Moreno, G.; Jeffers, J. R.; Narumanchi, S.; Bennion, K.

2014-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "hydrofluorocarbons hfcs perfluorocarbons" 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.


61

Final report on activities and findings under DOE grant “Interactive Photochemistry in Earth System Models to Assess Uncertainty in Ozone and Greenhouse Gases”  

SciTech Connect (OSTI)

Atmospheric chemistry controls the abundances and hence climate forcing of important greenhouse gases including N2O, CH4, HFCs, CFCs, and O3. Attributing climate change to human activities requires, at a minimum, accurate models of the chemistry and circulation of the atmosphere that relate emissions to abundances. This DOE-funded research provided realistic, yet computationally optimized and affordable, photochemical modules to the Community Earth System Model (CESM) that augment the CESM capability to explore the uncertainty in future stratospheric-tropospheric ozone, stratospheric circulation, and thus the lifetimes of chemically controlled greenhouse gases from climate simulations. To this end, we have successfully implemented Fast-J (radiation algorithm determining key chemical photolysis rates) and Linoz v3.0 (linearized photochemistry for interactive O3, N2O, NOy and CH4) packages in LLNL-CESM and for the first time demonstrated how change in O2 photolysis rate within its uncertainty range can significantly impact on the stratospheric climate and ozone abundances. From the UCI side, this proposal also helped LLNL develop a CAM-Superfast Chemistry model that was implemented for the IPCC AR5 and contributed chemical-climate simulations to CMIP5.

Prather, Michael J. [UCI

2014-11-07T23:59:59.000Z

62

Global warming implications of non-fluorocarbon technologies as CFC replacements  

SciTech Connect (OSTI)

Many technologies could be developed for use in place of conventional compression systems for refrigeration and air conditioning. Comparisons of the global warming impacts using TEWI (Total Equivalent Warming Impact) can be used to identify alternatives that have the potential for lower environmental impacts than electric-driven vapor compression systems using HCFCs and HFCs. Some options, such as secondary heat transfer loops in commercial refrigeration systems to reduce refrigerant charge and emission rates, could be useful in reducing the losses of refrigerants to the atmosphere. Use of ammonia instead of a fluorocarbon in a system with a secondary loop offers only a small potential for decreasing TEWI, and this may not warrant the increased complexity and risks of using ammonia in a retail sales environment. A few technologies, such as adsorption heat pumps, have efficiency levels that show reduced TEWI levels compared to conventional and state of the art compression systems, and further development could lead to an even more favorable comparison. Health and safety risks of the alternative technologies and the materials they employ must also be considered.

Fischer, S.K.; Tomlinson, J.J.

1993-12-31T23:59:59.000Z

63

Global warming and end-use efficiency implications of replacing CFCs  

SciTech Connect (OSTI)

The direct contribution of CFCs to calculated global warming has been recognized for some time. As a result of the international agreement to phase out CFCs due to stratospheric ozone and the ensuing search for suitable alternatives, there has recently been increased attention on the DIRECT global warming potential (GWP) of the fluorocarbon alternatives as greenhouse gases. However, to date there has been little focus on the INDIRECT global warming effect arising from end-use efficiency changes and associated CO{sub 2} emissions. A study being conducted at Oak Ridge National Laboratory (ORNL) addresses this combined or total global warming impact of viable options to replace CFCs in their major energy-related applications. This paper reviews selected results for air-conditioning, refrigeration, and heat pump applications. The analysis indicates that the CFC user industries have made substantial progress in approaching near-equal energy efficiency with the HCFC/HFC alternative refrigerants. The findings also bring into question the relative importance of the DIRECT (chemical-related) effect in many applications. Replacing CFCs is an important step in reducing the total global warming impact, and at present the HCFC and HFCS appear to offer the best efficiency and lowest total impact of options available in the relatively short time period required for the transition away from CFCs.

Fairchild, P.D.; Fischer, S.K.

1991-12-31T23:59:59.000Z

64

Effects of Water in Synthetic Lubricant Systems and Clathrate Formation: A Literature Search and Review  

SciTech Connect (OSTI)

An extensive literature search and a confidential survey were critically analyzed to determine the effects of water on the stability of hydrofluorocarbon/synthetic lubricant systems and to identify key areas requiring further investigation. Following are highlights from the analysis: Clathrate hydrates are solid solutions formed when water molecules are linked through hydrogen bonding creating cavities that can enclose various guest molecules from hydrate formers, such as hydrofluorocarbons R-32, R-125, R-134a, R-407C and R-410A. The four methods for preventing clathrate formation were drying the gas, heating it, reducing its pressure, or using inhibitors. The hydrolysis of polyolester lubricants was mostly acid-catalyzed and its reaction rate constant typically followed the Arrhenius equation of an activated process. Hydrolytic stability improved with hindered molecular structures, and with the presence of acid catcher additives and desiccants. Water vapor can effect the adsorption of long-chain fatty acids and the chemistry of formation of protective oxide film. However, these effects on lubrication can be either positive or negative. Fifty to sixty percent of the moisture injected into an air-conditioning system remained in the refrigerant and the rest mixed with the compressor oil. In an automotive air-conditioning system using R-134a, ice would form at 0 C evaporating temperature when the water content in the vapor refrigerant on the low-pressure side was more than 350 ppm. Moisture would cause the embrittlement of polyethylene terephthalate and the hydrolysis of polyesters, but would reduce the effect of amine additives on fluoroelastomer rubbers. The reactions of water with refrigerants and lubricants would cause formicary and large-pit corrosion in copper tubes, as well as copper plating and sludge formation. Moreover, blockage of capillary tubes increased rapidly in the presence of water. Twenty-four companies responded to the survey. From the responses, the water concentrations specified and expected for different refrigerant/lubricant systems varied depending on the products, their capacities and applications, and also on the companies. Among the problems associated with high moisture level, lubricant breakdown was of greatest concern, followed by acid formation, compressor failure and expansion valve sticking. The following research topics are suggested: 1. The air-conditioning and refrigeration industry needs to measure and record the water content and total acid number of the lubricant of newly installed systems as well as operating systems that are shutdown for service or repair. The reason for the shutdown needs to be documented. A database can then be established to correlate water content with type and cause of breakdown. 2. Detailed studies on the distribution of water in refrigeration and air-conditioning systems should be conducted to pinpoint problem areas associated with free water. 3. Research is needed to validate the current theories and mechanisms of formicary corrosion. Corrosion inhibitors need to be developed. 4. The conditions for clathrate formation and decomposition of other alternative refrigerants, such as R-23, R-41, R-116, R-125, R-143a, R-404A and R-507C, and water should be determined to avoid possible problems associated with tube plugging. The mechanism by which water facilitates or hinders lubrication needs to be studied.

Rohatgi, Ngoc Dung T.

2001-08-08T23:59:59.000Z

65

Toxicity of trifluoroacetate to aquatic organisms  

SciTech Connect (OSTI)

As a result of the atmospheric degradation of several hydrofluorocarbons and hydrochlorofluorocarbons, trifluoroacetate (TFA) will be formed. Through precipitation, TFA will enter aquatic ecosystems. To evaluate the impact on the aquatic environment, an aquatic toxicity testing program was carried out with sodium trifluoroacetate (NaTFA). During acute toxicity tests, no effects of NaTFA on water fleas (Daphnia magna) and zebra fish (Danio retrio) were found at a concentration of 1,200 mg/L. A 7-d study with duckweed (Lemna gibba Ge) revealed a NOEC of 300 mg/L. On the basis of the results of five toxicity tests with Selenastrum capricornutum, they determined a NOEC of 0.12 mg/L. However, algal toxicity tests with NaTFA and Chlorella vulgaris, Scenedesmus subspicatus, Chlamydomonas reinhardtii, Dunaliella tertiolecta, Eugelan gracilis, Phaeodactylum tricornutum, Navicula pelliculosa, Skeletonema costatum, Anabaena flos-aquae, and Microcystis aeruginosa resulted in EC50 values that were all higher than 100 mg/L. The toxicity of TFA to S. capricornutum could be due to metabolic defluorination to monofluoroacetate (MFA), which is known to inhibit the citric acid cycle. A toxicity test with MFA and S. capricornutum revealed it to be about three orders of magnitude more toxic than TFA. However, a bioactivation study revealed that defluorination of TFA was less than 4%. On the other hand, S. capricornutum exposed to a toxic concentration of NaTFA showed a recovery of growth when citric acid was added, suggesting that TFA (or a metabolite of TFA) interferes with the citric acid cycle. A recovery of the growth of S. capricornutum was also found when TFA was removed from the test solutions. Therefore, TFA should be considered algistatic and not algicidic for S. capricornutum. On the basis of the combined results of the laboratory tests and a previously reported semi-field study, they can consider a TFA concentration of 0.10 mg/L as safe for the aquatic ecosystem.

Berends, A.G.; Rooij, C.G. de [Solvay S.A., Brussels (Belgium); Boutonnet, J.C. [Elf Atochem, Levallois-Perret (France); Thompson, R.S. [Zeneca Ltd., Devon (United Kingdom). Brixham Environmental Lab.

1999-05-01T23:59:59.000Z

66

An Evaluation of the Environmental Impact of Different Commercial Supermarket Refrigeration Systems Using Low Global Warming Potential Refrigerants  

SciTech Connect (OSTI)

Commercial refrigeration systems consumed 1.21 Quads of primary energy in 2010 and are known to be a major source for refrigerant charge leakage into the environment. Thus, it is important to study the environmental impact of commercial supermarket refrigeration systems and improve their design to minimize any adverse impacts. The system s Life Cycle Climate Performance (LCCP) was presented as a comprehensive metric with the aim of calculating the equivalent mass of carbon dioxide released into the atmosphere throughout its lifetime, from construction to operation and destruction. In this paper, an open source tool for the evaluation of the LCCP of different air-conditioning and refrigeration systems is presented and used to compare the environmental impact of a typical multiplex direct expansion (DX) supermarket refrigeration systems based on three different refrigerants as follows: two hydrofluorocarbon (HFC) refrigerants (R-404A, and R-407F), and a low global warming potential (GWP) refrigerant (N-40). The comparison is performed in 8 US cities representing different climates. The hourly energy consumption of the refrigeration system, required for the calculation of the indirect emissions, is calculated using a widely used building energy modeling tool (EnergyPlus). A sensitivity analysis is performed to determine the impact of system charge and power plant emission factor on the LCCP results. Finally, we performed an uncertainty analysis to determine the uncertainty in total emissions for both R-404A and N-40 operated systems. We found that using low GWP refrigerants causes a considerable drop in the impact of uncertainty in the inputs related to direct emissions on the uncertainty of the total emissions of the system.

Beshr, Mohamed [University of Maryland, College Park; Aute, Vikrant [University of Maryland, College Park; Abdelaziz, Omar [ORNL; Fricke, Brian A [ORNL; Radermacher, Reinhard [University of Maryland, College Park

2014-01-01T23:59:59.000Z

67

FLORIDA TOWER FOOTPRINT EXPERIMENTS  

SciTech Connect (OSTI)

The Florida Footprint experiments were a series of field programs in which perfluorocarbon tracers were released in different configurations centered on a flux tower to generate a data set that can be used to test transport and dispersion models. These models are used to determine the sources of the CO{sub 2} that cause the fluxes measured at eddy covariance towers. Experiments were conducted in a managed slash pine forest, 10 km northeast of Gainesville, Florida, in 2002, 2004, and 2006 and in atmospheric conditions that ranged from well mixed, to very stable, including the transition period between convective conditions at midday to stable conditions after sun set. There were a total of 15 experiments. The characteristics of the PFTs, details of sampling and analysis methods, quality control measures, and analytical statistics including confidence limits are presented. Details of the field programs including tracer release rates, tracer source configurations, and configuration of the samplers are discussed. The result of this experiment is a high quality, well documented tracer and meteorological data set that can be used to improve and validate canopy dispersion models.

WATSON,T.B.; DIETZ, R.N.; WILKE, R.; HENDREY, G.; LEWIN, K.; NAGY, J.; LECLERC, M.

2007-01-01T23:59:59.000Z

68

Uncertainties in Air Exchange using Continuous-Injection, Long-Term Sampling Tracer-Gas Methods  

SciTech Connect (OSTI)

The PerFluorocarbon Tracer (PFT) method is a low-cost approach commonly used for measuring air exchange in buildings using tracer gases. It is a specific application of the more general Continuous-Injection, Long-Term Sampling (CILTS) method. The technique is widely used but there has been little work on understanding the uncertainties (both precision and bias) associated with its use, particularly given that it is typically deployed by untrained or lightly trained people to minimize experimental costs. In this article we will conduct a first-principles error analysis to estimate the uncertainties and then compare that analysis to CILTS measurements that were over-sampled, through the use of multiple tracers and emitter and sampler distribution patterns, in three houses. We find that the CILTS method can have an overall uncertainty of 10-15percent in ideal circumstances, but that even in highly controlled field experiments done by trained experimenters expected uncertainties are about 20percent. In addition, there are many field conditions (such as open windows) where CILTS is not likely to provide any quantitative data. Even avoiding the worst situations of assumption violations CILTS should be considered as having a something like a ?factor of two? uncertainty for the broad field trials that it is typically used in. We provide guidance on how to deploy CILTS and design the experiment to minimize uncertainties.

Sherman, Max H.; Walker, Iain S.; Lunden, Melissa M.

2013-12-01T23:59:59.000Z

69

TheU-Tube: A Novel System for Acquiring Borehole Fluid Samplesfrom a Deep Geologic CO2 Sequestration Experiment  

SciTech Connect (OSTI)

A novel system has been deployed to obtain geochemical samples of water and gas, at in situ pressure, during a geologic CO2 sequestration experiment conducted in the Frio brine aquifer in Liberty County, Texas. Project goals required high-frequency recovery of representative and uncontaminated aliquots of a rapidly changing two-phase (supercritical CO2-brine) fluid from 1.5 km depth. The datasets collected, using both the liquid and gas portions of the downhole samples, provide insights into the coupled hydro-geochemical issues affecting CO2 sequestration in brine-filled formations. While the basic premise underlying the U-Tube sampler is not new, the system is unique because careful consideration was given to the processing of the recovered two-phase fluids. In particular, strain gauges mounted beneath the high-pressure surface sample cylinders measured the ratio of recovered brine to supercritical CO2. A quadrupole mass spectrometer provided real-time gas analysis for perfluorocarbon and noble gas tracers that were injected along with the CO2. The U-Tube successfully acquired frequent samples, facilitating accurate delineation of the arrival of the CO2 plume, and on-site analysis revealed rapid changes in geochemical conditions.

Freifeld, Barry M.; Trautz, Robert C.; Kharaka, Yousif K.; Phelps, Tommy J.; Myer, Larry R.; Hovorka, Susan D.; Collins, Daniel J.

2005-03-17T23:59:59.000Z

70

Taggants, method for forming a taggant, and a method for detecting an object  

DOE Patents [OSTI]

A taggant comprising at least one perfluorocarbon compound surrounded by a polyphosphazene compound. The polyphosphazene compound has the chemical structure: ##STR00001## wherein G.sub.1 and G.sub.2 are pendant groups having different polarities, m is an integer greater than or equal to 100, and each of A and B is independently selected from hydrogen, an alkyl, an alkene, an alkoxide, a polyether, a polythioether, a siloxane, and --X(CH.sub.2).sub.nY.sup.1(CH.sub.2)p.sub.1Y.sup.2(CH.sub.2)p.sub.2 . . . Y.sup.i(CH.sub.2)p.sub.iCH.sub.3, where n ranges from 1 to 6, X and Y are independently selected from oxygen, sulfur, selenium, tellurium, and polonium, and p.sub.1 through p.sub.i range from 1 to 6. Cyclic polyphosphazene compounds lacking the A and B groups are also disclosed, as are methods of forming the taggant and of detecting an object.

Harrup, Mason K. (Idaho Falls, ID); Stewart, Frederick F. (Idaho Falls, ID); Stone, Mark L. (Idaho Falls, ID)

2012-02-28T23:59:59.000Z

71

Innovative techniques for the description of reservoir heterogeneity using tracers. Second technical annual progress report, October 1991--September 1992  

SciTech Connect (OSTI)

This second annual report on innovative uses of tracers for reservoir characterization contains four sections each describing a novel use of oilfield tracers. The first section describes and illustrates the use of a new single-well tracer test to estimate wettability. This test consists of the injection of brine containing tracers followed by oil containing tracers, a shut-in period to allow some of the tracers to react, and then production of the tracers. The inclusion of the oil injection slug with tracers is unique to this test, and this is what makes the test work. We adapted our chemical simulator, UTCHEM, to enable us to study this tracer method and made an extensive simulation study to evaluate the effects of wettability based upon characteristic curves for relative permeability and capillary pressure for differing wetting states typical of oil reservoirs. The second section of this report describes a new method for analyzing interwell tracer data based upon a type-curve approach. Theoretical frequency response functions were used to build type curves of ``transfer function`` and ``phase spectrum`` that have dimensionless heterogeneity index as a parameter to characterize a stochastic permeability field. We illustrate this method by analyzing field tracer data. The third section of this report describes a new theory for interpreting interwell tracer data in terms of channeling and dispersive behavior for reservoirs. Once again, a stochastic approach to reservoir description is taken. The fourth section of this report describes our simulation of perfluorocarbon gas tracers. This new tracer technology developed at Brookhaven National Laboratory is being tested at the Elk Hills Naval Petroleum Reserve No. 1 in California. We report preliminary simulations made of these tracers in one of the oil reservoirs under evaluation with these tracers in this field. Our compostional simulator (UTCOMP) was used for this simulation study.

Pope, G.A.; Sepehrnoori, K.

1992-12-31T23:59:59.000Z

72

Side-by-side evaluation of a stressed-skin insulated-core panel house and a conventional stud-frame house. Final report  

SciTech Connect (OSTI)

Side-by-side energy testing and monitoring was conducted on two houses in Louisville, KY between January--March 1993. Both houses were identical except that one house was constructed with conventional US 2 by 4 studs and a truss roof while the other house was constructed with stress-skin insulated core panels for the walls and second floor ceiling. Air-tightness testing included fan pressurization by blower door, hour long tracer tests using sulphur hexafluoride, and two-week long time-averaged tests using perfluorocarbon tracers. An average of all the air-tightness test results showed the SSIC panel house to have 22 percent less air infiltration than the frame house. Air-tightness testing resulted in a recommendation that both houses have a fresh air ventilation system installed to provide 0.35 air changes per hour continuously. Thermal insulation quality testing was by infrared imaging. Pressure differential testing resulted in recommendations to use sealed combustion appliances, and to allow for more return air flow from closed rooms. This can be accomplished by separate return ducts or transfer ducts which simply connect closed rooms to the main body with a short duct. The SSIC house UA was lower in both cases. By measurement, co-heating tests showed the SSIC panel house total UA to be 12 percent lower than the frame house. Short-term energy monitoring was also conducted for the two houses. A 17 day period of electric heating and a 14 day period of gas furnace heating was evaluated. Monitoring results showed energy savings for the panel house to be 12 percent during electric heating and 15 percent during gas heating. A comparison of the two monitoring periods showed that the lumped efficiency of the gas furnace and air distribution system for both houses was close to 80 percent. Simple regression models using Typical Meteorological Year weather data gave a preliminary prediction of seasonal energy savings between 14 and 20 percent.

Rudd, A.; Chandra, S.

1994-01-14T23:59:59.000Z

73

Desalination utilizing clathrate hydrates (LDRD final report).  

SciTech Connect (OSTI)

Advances are reported in several aspects of clathrate hydrate desalination fundamentals necessary to develop an economical means to produce municipal quantities of potable water from seawater or brackish feedstock. These aspects include the following, (1) advances in defining the most promising systems design based on new types of hydrate guest molecules, (2) selection of optimal multi-phase reactors and separation arrangements, and, (3) applicability of an inert heat exchange fluid to moderate hydrate growth, control the morphology of the solid hydrate material formed, and facilitate separation of hydrate solids from concentrated brine. The rate of R141b hydrate formation was determined and found to depend only on the degree of supercooling. The rate of R141b hydrate formation in the presence of a heat exchange fluid depended on the degree of supercooling according to the same rate equation as pure R141b with secondary dependence on salinity. Experiments demonstrated that a perfluorocarbon heat exchange fluid assisted separation of R141b hydrates from brine. Preliminary experiments using the guest species, difluoromethane, showed that hydrate formation rates were substantial at temperatures up to at least 12 C and demonstrated partial separation of water from brine. We present a detailed molecular picture of the structure and dynamics of R141b guest molecules within water cages, obtained from ab initio calculations, molecular dynamics simulations, and Raman spectroscopy. Density functional theory calculations were used to provide an energetic and molecular orbital description of R141b stability in both large and small cages in a structure II hydrate. Additionally, the hydrate of an isomer, 1,2-dichloro-1-fluoroethane, does not form at ambient conditions because of extensive overlap of electron density between guest and host. Classical molecular dynamics simulations and laboratory trials support the results for the isomer hydrate. Molecular dynamics simulations show that R141b hydrate is stable at temperatures up to 265K, while the isomer hydrate is only stable up to 150K. Despite hydrogen bonding between guest and host, R141b molecules rotated freely within the water cage. The Raman spectrum of R141b in both the pure and hydrate phases was also compared with vibrational analysis from both computational methods. In particular, the frequency of the C-Cl stretch mode (585 cm{sup -1}) undergoes a shift to higher frequency in the hydrate phase. Raman spectra also indicate that this peak undergoes splitting and intensity variation as the temperature is decreased from 4 C to -4 C.

Simmons, Blake Alexander; Bradshaw, Robert W.; Dedrick, Daniel E.; Cygan, Randall Timothy (Sandia National Laboratories, Albuquerque, NM); Greathouse, Jeffery A. (Sandia National Laboratories, Albuquerque, NM); Majzoub, Eric H. (University of Missouri, Columbia, MO)

2008-01-01T23:59:59.000Z

74

Modeling of CBM production, CO{sub 2} injection, and tracer movement at a field CO{sub 2} sequestration site  

SciTech Connect (OSTI)

Sequestration of carbon dioxide in unmineable coal seams is a potential technology mainly because of the potential for simultaneous enhanced coalbed methane production (ECBM). Several pilot tests have been performed around the globe leading to mixed results. Numerous modeling efforts have been carried out successfully to model methane production and carbon dioxide (CO{sub 2}) injection. Sensitivity analyses and history matching along with several optimization tools were used to estimate reservoir properties and to investigate reservoir performance. Geological and geophysical techniques have also been used to characterize field sequestration sites and to inspect reservoir heterogeneity. The fate and movement of injected CO{sub 2} can be determined by using several monitoring techniques. Monitoring of perfluorocarbon (PFC) tracers is one of these monitoring technologies. As a part of this monitoring technique, a small fraction of a traceable fluid is added to the injection wellhead along with the CO{sub 2} stream at different times to monitor the timing and location of the breakthrough in nearby monitoring wells or offset production wells. A reservoir modeling study was performed to simulate a pilot sequestration site located in the San Juan coal basin of northern New Mexico. Several unknown reservoir properties at the field site were estimated by modeling the coal seam as a dual porosity formation and by history matching the methane production and CO{sub 2} injection. In addition to reservoir modeling of methane production and CO{sub 2} injection, tracer injection was modeled. Tracers serve as a surrogate for determining potential leakage of CO{sub 2}. The tracer was modeled as a non-reactive gas and was injected into the reservoir as a mixture along with CO{sub 2}. Geologic and geometric details of the field site, numerical modeling details of methane production, CO{sub 2} injection, and tracer injection are presented in this paper. Moreover, the numerical predictions of the tracer arrival times were compared with the measured field data. Results show that tracer modeling is useful in investigating movement of injected CO{sub 2} into the coal seam at the field site. Also, such new modeling techniques can be utilized to determine potential leakage pathways, and to investigate reservoir anisotropy and heterogeneity.

Siriwardane, Hema J.; Bowes, Benjamin D.; Bromhal, Grant S.; Gondle, Raj K.; Wells, Arthur W.; Strazisar, Brian R.

2012-07-01T23:59:59.000Z

75

Using Acid Number as a Leading Indicator of Refrigeration and Air Conditioning System Performance  

SciTech Connect (OSTI)

This report summarizes a literature review to assess the acidity characteristics of the older mineral oil and newer polyolester (POE) refrigeration systems as well as to evaluate acid measuring techniques used in other non-aqueous systems which may be applicable for refrigeration systems. Failure in the older chlorofluorocarbon/hydrochlorofluorocarbon (CFC/HCFC) / mineral oil systems was primarily due to thermal degradation of the refrigerant which resulted in the formation of hydrochloric and hydrofluoric acids. These are strong mineral acids, which can, over time, severely corrode the system metals and lead to the formation of copper plating on iron surfaces. The oil lubricants used in the older systems were relatively stable and were not prone to hydrolytic degradation due to the low solubility of water in oil. The refrigerants in the newer hydrofluorocarbon (HFC)/POE systems are much more thermally stable than the older CFC/HCFC refrigerants and mineral acid formation is negligible. However, acidity is produced in the new systems by hydrolytic decomposition of the POE lubricants with water to produce the parent organic acids and alcohols used to prepare the POE. The individual acids can therefore vary but they are generally C5 to C9 carboxylic acids. Organic acids are much weaker and far less corrosive to metals than the mineral acids from the older systems but they can, over long time periods, react with metals to form carboxylic metal salts. The salts tend to accumulate in narrow areas such as capillary tubes, particularly if residual hydrocarbon processing chemicals are present in the system, which can lead to plugging. The rate of acid production from POEs varies on a number of factors including chemical structure, moisture levels, temperature, acid concentration and metals. The hydrolysis rate of reaction can be reduced by using driers to reduce the free water concentration and by using scavenging chemicals which react with the system acids. Total acid number (TAN), which includes both mineral acids and organic acids, is therefore a useful indicator which can be used to monitor the condition of the system in order to perform remedial maintenance, when required, to prevent system failure. The critical TAN value is the acid level at which remedial action should be taken to prevent the onset of rapid acid formation which can result in system failure. The level of 0.05 mg KOH/g of oil was established for CFC/mineral oil systems based on analysis of 700 used lubricants from operating systems and failed units. There is no consensus within the refrigeration industry as to the critical TAN value for HFC/POE systems, however, the value will be higher than the CFC/mineral oil systems critical TAN value because of the much weaker organic acids produced from POE. A similar study of used POE lubricants should be performed to establish a critical TAN limit for POE systems. Titrimetric analysis per ASTM procedures is the most commonly used method to determine TAN values in lubricants in the refrigeration industry and other industries dealing with lubricating oils. For field measurements, acid test kits are often used since they provide rapid, semi-quantitative TAN results.

Dennis Cartlidge; Hans Schellhase

2003-07-31T23:59:59.000Z

76

Evaluation of metrics and baselines for tracking greenhouse gas emissions trends: Recommendations for the California climate action registry  

SciTech Connect (OSTI)

Executive Summary: The California Climate Action Registry, which was initially established in 2000 and began operation in Fall 2002, is a voluntary registry for recording annual greenhouse gas (GHG) emissions. The purpose of the Registry is to assist California businesses and organizations in their efforts to inventory and document emissions in order to establish a baseline and to document early actions to increase energy efficiency and decrease GHG emissions. The State of California has committed to use its ''best efforts'' to ensure that entities that establish GHG emissions baselines and register their emissions will receive ''appropriate consideration under any future international, federal, or state regulatory scheme relating to greenhouse gas emissions.'' Reporting of GHG emissions involves documentation of both ''direct'' emissions from sources that are under the entity's control and indirect emissions controlled by others. Electricity generated by an off-site power source is consider ed to be an indirect GHG emission and is required to be included in the entity's report. Registry participants include businesses, non-profit organizations, municipalities, state agencies, and other entities. Participants are required to register the GHG emissions of all operations in California, and are encouraged to report nationwide. For the first three years of participation, the Registry only requires the reporting of carbon dioxide (CO2) emissions, although participants are encouraged to report the remaining five Kyoto Protocol GHGs (CH4, N2O, HFCs, PFCs, and SF6). After three years, reporting of all six Kyoto GHG emissions is required. The enabling legislation for the Registry (SB 527) requires total GHG emissions to be registered and requires reporting of ''industry-specific metrics'' once such metrics have been adopted by the Registry. The Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) was asked to provide technical assistance to the California Energy Commission (Energy Commission) related to the Registry in three areas: (1) assessing the availability and usefulness of industry-specific metrics, (2) evaluating various methods for establishing baselines for calculating GHG emissions reductions related to specific actions taken by Registry participants, and (3) establishing methods for calculating electricity CO2 emission factors. The third area of research was completed in 2002 and is documented in Estimating Carbon Dioxide Emissions Factors for the California Electric Power Sector (Marnay et al., 2002). This report documents our findings related to the first areas of research. For the first area of research, the overall objective was to evaluate the metrics, such as emissions per economic unit or emissions per unit of production that can be used to report GHG emissions trends for potential Registry participants. This research began with an effort to identify methodologies, benchmarking programs, inventories, protocols, and registries that u se industry-specific metrics to track trends in energy use or GHG emissions in order to determine what types of metrics have already been developed. The next step in developing industry-specific metrics was to assess the availability of data needed to determine metric development priorities. Berkeley Lab also determined the relative importance of different potential Registry participant categories in order to asses s the availability of sectoral or industry-specific metrics and then identified industry-specific metrics in use around the world. While a plethora of metrics was identified, no one metric that adequately tracks trends in GHG emissions while maintaining confidentiality of data was identified. As a result of this review, Berkeley Lab recommends the development of a GHG intensity index as a new metric for reporting and tracking GHG emissions trends.Such an index could provide an industry-specific metric for reporting and tracking GHG emissions trends to accurately reflect year to year changes while protecting proprietary data. This GHG intensity index changes

Price, Lynn; Murtishaw, Scott; Worrell, Ernst

2003-06-01T23:59:59.000Z

77

Industry  

SciTech Connect (OSTI)

This chapter addresses past, ongoing, and short (to 2010) and medium-term (to 2030) future actions that can be taken to mitigate GHG emissions from the manufacturing and process industries. Globally, and in most countries, CO{sub 2} accounts for more than 90% of CO{sub 2}-eq GHG emissions from the industrial sector (Price et al., 2006; US EPA, 2006b). These CO{sub 2} emissions arise from three sources: (1) the use of fossil fuels for energy, either directly by industry for heat and power generation or indirectly in the generation of purchased electricity and steam; (2) non-energy uses of fossil fuels in chemical processing and metal smelting; and (3) non-fossil fuel sources, for example cement and lime manufacture. Industrial processes also emit other GHGs, e.g.: (1) Nitrous oxide (N{sub 2}O) is emitted as a byproduct of adipic acid, nitric acid and caprolactam production; (2) HFC-23 is emitted as a byproduct of HCFC-22 production, a refrigerant, and also used in fluoroplastics manufacture; (3) Perfluorocarbons (PFCs) are emitted as byproducts of aluminium smelting and in semiconductor manufacture; (4) Sulphur hexafluoride (SF{sub 6}) is emitted in the manufacture, use and, decommissioning of gas insulated electrical switchgear, during the production of flat screen panels and semiconductors, from magnesium die casting and other industrial applications; (5) Methane (CH{sub 4}) is emitted as a byproduct of some chemical processes; and (6) CH{sub 4} and N{sub 2}O can be emitted by food industry waste streams. Many GHG emission mitigation options have been developed for the industrial sector. They fall into three categories: operating procedures, sector-wide technologies and process-specific technologies. A sampling of these options is discussed in Sections 7.2-7.4. The short- and medium-term potential for and cost of all classes of options are discussed in Section 7.5, barriers to the application of these options are addressed in Section 7.6 and the implication of industrial mitigation for sustainable development is discussed in Section 7.7. Section 7.8 discusses the sector's vulnerability to climate change and options for adaptation. A number of policies have been designed either to encourage voluntary GHG emission reductions from the industrial sector or to mandate such reductions. Section 7.9 describes these policies and the experience gained to date. Co-benefits of reducing GHG emissions from the industrial sector are discussed in Section 7.10. Development of new technology is key to the cost-effective control of industrial GHG emissions. Section 7.11 discusses research, development, deployment and diffusion in the industrial sector and Section 7.12, the long-term (post-2030) technologies for GHG emissions reduction from the industrial sector. Section 7.13 summarizes gaps in knowledge.

Bernstein, Lenny; Roy, Joyashree; Delhotal, K. Casey; Harnisch, Jochen; Matsuhashi, Ryuji; Price, Lynn; Tanaka, Kanako; Worrell, Ernst; Yamba, Francis; Fengqi, Zhou; de la Rue du Can, Stephane; Gielen, Dolf; Joosen, Suzanne; Konar, Manaswita; Matysek, Anna; Miner, Reid; Okazaki, Teruo; Sanders, Johan; Sheinbaum Parado, Claudia

2007-12-01T23:59:59.000Z

78

PROOF OF CONCEPT TEST OF A UNIQUE GASEOUS PERFLUROCARBON TRACER SYSTEM FOR VERIFICATION AND LONG TERM MONITORING OF CAPS AND COVER SYSTEMS CONDUCTED AT THE SAVANNAH RIVER SITE BENTONITE MAT TEST FACILITY.  

SciTech Connect (OSTI)

Engineered covers have been placed on top of buried/subsurface wastes to minimize water infiltration and therefore, release of hazardous contaminants. In order for the cover to protect the environment it must remain free of holes and breaches throughout its service life. Covers are subject to subsidence, erosion, animal intrusion, plant root infiltration, etc., all of which will affect the overall performance of the cover. The U.S. Department of Energy Environmental Management (DOE-EM) Program 2006 Accelerated Cleanup Plan is pushing for rapid closure of many of the DOE facilities. This will require a great number of new cover systems. Some of these new covers are expected to maintain their performance for periods of up to 1000 years. Long-term stewardship will require monitoring/verification of cover performance over the course of the designed lifetime. In addition, many existing covers are approaching the end of their design life and will need validation of current performance (if continued use is desired) or replacement (if degraded). The need for a reliable method of verification and long-term monitoring is readily apparent. Currently, failure is detected through monitoring wells downstream of the waste site. This is too late as the contaminants have already left the disposal area. The proposed approach is the use of gaseous Perfluorocarbon tracers (PFT) to verify and monitor cover performance. It is believed that PFTs will provide a technology that can verify a cover meets all performance objectives upon installation, be capable of predicting changes in cover performance and failure (defined as contaminants leaving the site) before it happens, and be cost-effective in supporting stewardship needs. The PFTs are injected beneath the cover and air samples taken above (either air samples or soil gas samples) at the top of the cover. The location, concentrations, and time of arrival of the tracer(s) provide a direct measure of cover performance. PFT technology can be used as a non-invasive method (if injection ports are emplaced prior to cover emplacement) on new covers or a minimally invasive method on existing covers. PFT verification will be useful at all buried waste sites using a cover system (e.g., treated or untreated chemical waste landfills) including DOE, commercial, and private sector sites. This paper discusses the initial field trial of the PFT cover monitoring system performed at the Savannah River Site (SRS) in FY01. The experiments provided a successful proof-of-principle test of the PFT technology in monitoring caps and covers. An injection and sampling array was installed in the Bentomat test cap at the SRS Caps Test Facility. This system contained 6 feet of sandy soil beneath a 1/2 inch geosynthetic clay liner covered by an HDPE liner which was covered by 2 feet of clayey top soil. PFTs were injected into the sandy soil though a pre-existing system of access pipes below the cap and soil gas samples were taken on top of the cap. Mid-way into the injection period a series of 1 1/2 inch holes were punched into the cap (through the geomembrane) to provide a positive breach in the cap. Data will be presented that shows the initial cap was fairly tight and leak free and that the artificially induced leaks were detectable within two hours of occurrence.

HEISER,J.; SULLIVAN,T.; SERRATO,M.

2002-02-24T23:59:59.000Z