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1

Fluid catalytic cracking of heavy petroleum fractions  

SciTech Connect (OSTI)

A process is claimed for fluid catalytic cracking of residuum and other heavy oils comprising of gas oil, petroleum residue, reduced and whole crudes and shale oil to produce gasoline and other liquid products which are separated in various streams in a fractionator and associated vapor recovery equipment. The heat from combustion of coke on the coked catalyst is removed by reacting sulfur-containing coke deposits with steam and oxygen in a separate stripper-gasifier to produce a low btu gas stream comprising of sulfur compounds, methane, carbon monoxide, hydrogen, and carbon dioxide at a temperature of from about 1100/sup 0/F. To about 2200/sup 0/F. The partially regenerated catalyst then undergoes complete carbon removal in a regeneration vessel. The regenerated catalyst is recycled for re-use in the cracking of heavy petroleum fractions. The liquid products are gasoline, distillates, heavy fuel oil, and light hydrocarbons.

McHenry, K.W.

1981-06-30T23:59:59.000Z

2

Energy Recovery System for Fluid Catalytic Cracking Units  

E-Print Network [OSTI]

This paper describes the power and heat recovery processes and equipment for modern fluid catalytic cracking (FCC) units made possible by improvements in catalyst fines removal technology and the availability of erosion resistant high temperature...

Wen, H.; Lou, S. C.

1982-01-01T23:59:59.000Z

3

TCS 2014 Symposium on Thermal and Catalytic Sciences for Biofuels...  

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

TCS 2014 Symposium on Thermal and Catalytic Sciences for Biofuels and Biobased Products TCS 2014 Symposium on Thermal and Catalytic Sciences for Biofuels and Biobased Products...

4

“Petroleum Gas Oil?Ethanol” Blends Used as Feeds: Increased Production of Ethylene and Propylene over Catalytic Steam-Cracking (CSC) Hybrid Catalysts. Different Behavior of Methanol in Blends with Petroleum Gas Oil  

Science Journals Connector (OSTI)

“Petroleum Gas Oil?Ethanol” Blends Used as Feeds: Increased Production of Ethylene and Propylene over Catalytic Steam-Cracking (CSC) Hybrid Catalysts. ... Recently developed hybrid catalysts used in the catalytic steam cracking (CSC, formerly called selective deep catalytic cracking or SDCC(1, 2) and also thermal catalytic cracking or TCC(3, 4)) of hydrocarbon heavy feedstocks (naphthas and gas oils) are very efficient in the production of light olefins, particularly ethylene and propylene with a product propylene-to-ethylene ratio close to 1.0. ...

A. Muntasar; R. Le Van Mao; H. T. Yan

2010-03-22T23:59:59.000Z

5

Reaction kinetics of olefin saturation in the hydrodesulfurization of fluid catalytic cracked naphtha  

E-Print Network [OSTI]

U.S. governmental agencies are calling for strict environmental regulations on the quality of gasoline. Fluid catalytic cracked naphtha is an important blending component of the gasoline pool. The majority of the sulfur in the gasoline pool comes...

Schumann, Brian Herbert

2012-06-07T23:59:59.000Z

6

Spectroscopic studies on the formation of coke on individual Fluid Catalytic Cracking particles: the effect of poisoning metal compounds.  

E-Print Network [OSTI]

??The formation of coke on individual Fluid Catalytic Cracking (FCC) catalyst particles was studied using UV/Vis microspectroscopy and confocal fluorescence microscopy, with n-hexane cracking as… (more)

Goetze, J.G.

2013-01-01T23:59:59.000Z

7

A heavy oil thermal cracking simulation program  

SciTech Connect (OSTI)

Correlations were developed to simulate the thermal cracking reaction of petroleum vacuum distillation residues through pilot plant data analysis. They use charge properties like specific gravity, viscosity, sulphur content and initial boiling point to give the yield and quality of products as a function of conversion, which is measured in terms of wt.% products with normal boiling point below 350{degrees}C. The mixture is represented with 24 lumps, and kinetic parameters for the reaction feed {r_arrow} products were also found as a function of feedstock properties. Finally, a computer program was developed to simulate fired heater operation for visbreaking and delayed coking units. 3 refs., 10 figs., 1 tab.

Maciel, R. [UNICAMP, Campinas (Brazil); Sugaya, M.F. [Petrobrais, Rio de Janeiro (Brazil)

1996-12-31T23:59:59.000Z

8

Hydrodesulfurization of Fluid Catalytic Cracking Decant Oils for the Production of Low-sulfur Needle Coke Feedstocks.  

E-Print Network [OSTI]

??Needle coke, produced by the delayed coking of fluid catalytic cracking decant oils, is the primary filler used in the production of graphite electrodes. The… (more)

Wincek, Ronald

2013-01-01T23:59:59.000Z

9

Thermal cracking in disc brakes Thomas J. Mackin *,1  

E-Print Network [OSTI]

Thermal cracking in disc brakes Thomas J. Mackin *,1 , Steven C. Noe, K.J. Ball, B.C. Bedell, D, or hub, which is connected to the wheel and axle, and an inboard and outboard braking surface

Salvaggio, Carl

10

Catalytic cracking of a Gippsland reduced crude on zeolite catalysts  

SciTech Connect (OSTI)

Cracking reactions of a Gippsland reduced crude have been investigated at 520[degrees]C over HY and HZSM-5. Gasolines with similar characteristics can be obtained on both zeolites, although the mechanistic routes to these products are quite distinct. Changes in aromatic product selectivities are consistent with the zeolite pore geometries. Minor quantities of aromatics are formed via hydrogen transfer processes involving product olefins and naphthenes over the faujasite and the cyclization (and to a lesser extent oligomerization) of olefinic species on the pentasil. Dehydrogenation of naphthenic species in the feedstock is also important for aromatic formation. While paraffins are formed via hydrogen transfer processes together with cracking and isomerization of feed paraffins on HY, only the latter route can explain formation of saturated species on HZSM-5. The removal of linear paraffins from the GRC was traced as a function of conversion on HY. It was found that the relative reactivity of the linear paraffins increased monotonically with paraffin chain length. 43 refs., 11 figs., 8 tabs.

Guerzoni, F.N.; Abbot, J. (Univ. of Tasmania (Australia))

1994-06-01T23:59:59.000Z

11

Relation between the characteristics of the pitches produced on the basis of heavy gas-oil of catalytic cracking  

SciTech Connect (OSTI)

Mesophase pitches are often used to produce carbon fibers. Results of microanalysis and fiber-forming ability of the pitches are described. The pitches were obtained by the catalytic cracking of heavy gas-oil.

Nikolaeva, L.V.; Bulanova, V.V. [Rossiiskaya Akadeiya, Nauk (Russian Federation)

1995-12-31T23:59:59.000Z

12

Task 3.9 -- Catalytic tar cracking. Semi-annual report, January 1--June 30, 1995  

SciTech Connect (OSTI)

Tar produced in the gasification of coal is deleterious to the operation of downstream equipment including fuel cells, gas turbines, hot-gas stream cleanup filters, and pressure swing adsorption systems. Catalytic cracking of tars to smaller hydrocarbons can be an effective means to remove these tars from gas streams and, in the process, generate useful products, e.g., methane gas, which is crucial to the operation of molten carbonate fuel cells. The objectives of this project are to investigate whether gasification tars can be cracked by synthetic nickel-substituted micamontmorillonite, zeolite, or dolomite material; and whether the tars can be cracked selectively by these catalysts to produce a desired liquid and/or gas stream. Results to date are presented in the cited papers.

Young, B.C.; Timpe, R.C.

1995-12-31T23:59:59.000Z

13

Features of hydrotreating catalytic cracking feed and heavy slow coking gas oils  

SciTech Connect (OSTI)

A possible means of more extensive processing of crude oil is the use, in catalytic cracking, of heavy coking gas oils (HCGOs), a feature of which is a higher content of polycyclic aromatic compounds and resins by comparison with straight-run vacuum distillates. The presence of these compounds in catalytic cracking feed causes a reduction in the product yield and increased coke formation. Therefore, one of the problems of hydrotreating feedstock of this kind is the hydrogenation of polycyclic arenes. Processes of extensive desulphurization and denitration occur in parallel, since the sulphur and nitrogen compounds of HCGO are chiefly condensed benzoderivatives of thiophene, pyridine and carbazole, and largely concentrated in heavy aromatic and resinous fractions. The composition of the saturated part of the cracking feed plays a large role in achieving the optimum yields of gaseous and gasoline fractions. Thus an increase in the proportion of cyclanes in the feed raises the gasoline yield. In this way, an investigation of the hydrocarbon conversions during the hydrotreatment of cracking feed is of great importance. The present paper sets out the results for studying the change in the group-structural characteristics of the hydrogenation products of a mixture containing 30% HCGOs according to data of {sup 1}H and {sup 13}C NMR spectroscopy. 7 refs., 7 figs., 1 tab.

Yefremov, N.I.; Kushnarev, D.F.; Frolov, P.A.; Chagovets, A.N.; Kalabin, G.A.

1993-12-31T23:59:59.000Z

14

Energy and environmental research emphasizing low-rank coal: Task 3.9 catalytic tar cracking  

SciTech Connect (OSTI)

Tar produced in the gasification of coal is deleterious to the operation of downstream equipment, including fuel cells, gas turbines, hot-gas stream cleanup filters, and pressure-swing absorption systems. Catalytic cracking of tars to smaller hydrocarbons can be an effective means of removing these tars from gas streams and, in the process, generating useful products, such as methane gas, which is crucial to operation of molten carbonate fuel cells. Aerosol tars are not readily removed from gas streams by conventional means and, as a consequence, often end up plugging filters or fouling fuel cells, turbines, or sorbents. Catalytic cracking of these tars to molecular moieties of C{sub 10} or smaller would prevent the problems commonly attributed to the tars. As an example, the moving Bourdon fixed-bed gasifier, by virtue of its efficient countercurrent heat exchange and widespread commercial use, may offer the lowest-cost integrated gasification combined-cycle (IGCC) system if tar generation and wastewater contamination can be minimized. We evaluate the potential of selected catalysts to minimize tar accumulation and maximize char conversion to useful liquid and/or gaseous products. Owing to the potential for production of extremely toxic nickel carbonyl gas, care must be exercised in the use of a NISMM catalyst for cracking tars at high temperatures in reducing atmospheres such as those produced by coal gasification. We observed a fifty percent or more of tar produced during steam gasification of Beulah lignite at temperatures of 400{degrees}-800+{degrees}C when cracked by either dolomite or zeolite maintained at a temperature of 50{degrees}C-100{degrees}C below that of the reactor.

Timpe, R.C.

1995-09-01T23:59:59.000Z

15

Hydrogen Crack Growth Resistance of Thermal Power Plant Material Collector  

Science Journals Connector (OSTI)

Abstract The influence of electrolytical hydrogenation on fracture toughness, corrosion crack-growth resistance and fracture micromechanisms of operated 12Cr1MoV steel of thermal power plant superheater collector has been studied. Compact tension specimens were cut from perforated surface of thermal power plant superheater collector dismounted after 178,500 hours of operation. Corrosion crack-growth resistance under tension of previously hydrogenated compact specimens with fatigue cracks was studied. Due to the increased concentration of hydrogen in solution an additional buffer was being created that prevents hydrogen leakage from the specimen through the fracture surface during the experiment. The hydrogenation causes the significant decrease of critical stress intensity factor Kc, during the experiment in 0.1 N NaOH solution as compared with critical stress intensity factor K of non-hydrogenation 12Cr1MoV steel obtained by the 5% secant line method and in comparison with critical stress intensity factor Kc, determined through the J-integral. The areas of ductile crack growth in hydrogenated and non-hydrogenated specimens were found to have similar material fracture micromechanisms with dimples creation of different shape and size. But on the ductile crack growth area in hydrogenated specimens material intergranular fracture mechanisms were found caused by the hydrogen embrittlement which are similar to areas without ridges with the products corrosion traces.

V. Iasnii; P. Maruschak; O. Yasniy; Y. Lapusta

2014-01-01T23:59:59.000Z

16

The selective catalytic cracking of Fischer-Tropsch liquids to high value transportation fuels. Final report  

SciTech Connect (OSTI)

Amoco Oil Company, investigated a selective catalytic cracking process (FCC) to convert the Fischer-Tropsch (F-T) gasoline and wax fractions to high value transportation fuels. The primary tasks of this contract were to (1) optimize the catalyst and process conditions of the FCC process for maximum conversion of F-T wax into reactive olefins for later production of C{sub 4}{minus}C{sub 8} ethers, and (2) use the olefin-containing light naphtha obtained from FCC processing of the F-T wax as feedstock for the synthesis of ethers. The catalytic cracking of F-T wax feedstocks gave high conversions with low activity catalysts and low process severities. HZSM-5 and beta zeolite catalysts gave higher yields of propylene, isobutylene, and isoamylenes but a lower gasoline yield than Y zeolite catalysts. Catalyst selection and process optimization will depend on product valuation. For a given catalyst and process condition, Sasol and LaPorte waxes gave similar conversions and product selectivities. The contaminant iron F-T catalyst fines in the LaPorte wax caused higher coke and hydrogen yields.

Schwartz, M.M.; Reagon, W.J.; Nicholas, J.J.; Hughes, R.D.

1994-11-01T23:59:59.000Z

17

Methods applied to investigate the major VCE that occured in the TOTAL refinery's Fluid Catalytic Cracking Unit at La Mede,  

E-Print Network [OSTI]

95-35 Methods applied to investigate the major �VCE that occured in the TOTAL refinery's Fluid.V.C.E, occured in the Gas Plant of the TOTAL refinery's Fluid Catalytic Cracking ünit at La Mede, France sources: control room hard copy and electronically stored records: no deviation of process operating

Paris-Sud XI, Université de

18

Influence of the nature of FCC feed on the production of light olefins by catalytic cracking  

SciTech Connect (OSTI)

The 1990 Clean Air Act has act rules for gasoline reformulation, which requires major compositional changes, Including a higher contribution of oxygenated compounds to the gasoline pool. This explains why FCC units are expected to play a major role in the coming years as a producer of light olefins (propylene, butenes and amylenes) to be used as feedstock for oxygenate (MTBE/TAME) production. The impact of the nature of FCC feedstock on light olefins production (C3 to C5 olefins) has been studied using a MAT unit running at various operating conditions (C/O ratio, reactor temperature). Paraffinic feeds are potentially efficient to produce light olefins by catalytic cracking. Heavier paraffinic feeds like mixtures VGO + reside and pure reside have also been evaluated, and compared to naphthenic and aromatic feeds.

Chapus, Th.; Cauffriez, H.; Marcilly, Ch. [Institut Francais du Petrole, Rueil-Malmaison (France)

1996-10-01T23:59:59.000Z

19

Enhanced thermal and gas flow performance in a three-way catalytic...  

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

flow performance in a three-way catalytic converter through use of insulation within the ceramic monolith Enhanced thermal and gas flow performance in a three-way catalytic...

20

Effects of Matrix Cracks on the Thermal Diffusivity of a Fiber-Reinforced Ceramic Composite  

E-Print Network [OSTI]

when the material is subjected to temperature gradients and is therefore relevant to its thermal shock resistance. The present study focuses on the effects of a periodic array of matrix cracks on thermal displacement are used to determine the contributions to the longitudinal thermal resistance due to each crack

Zok, Frank

Note: This page contains sample records for the topic "thermal catalytic cracking" 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

Fluid catalytic cracking feed hydrotreatment and its severity impact on product yields and quality  

Science Journals Connector (OSTI)

This paper investigates the effect of fluid catalytic cracking (FCC) feed hydrotreatment and its severity increase on product yields and quality obtained in a commercial and a laboratory MAT FCC units. The hydrotreatment of Ural heavy vacuum gas oil reduces not only sulfur, nitrogen, Conradson carbon and metals content in the FCC feed but also increases the mononuclear aromatic hydrocarbons content by 8% absolute at almost no change in the total aromatics content. Regardless of this 8% increase of the mononuclear aromatics in the hydrotreated FCC feed the conversion increase in both commercial and laboratory MAT units was only 2%. The severity increase in the FCC feed hydrotreater leads to a higher conversion in the FCC, higher hydrogen transfer rate that results in higher isobutane/butylenes ratio, lower gasoline olefins content, and higher gasoline motor octane number. The hydrotreatment of the Ural heavy vacuum gas oil exhibited the same changes in FCC catalyst selectivities: lower coke and LCO selectivities and higher gasoline selectivity in both commercial riser FCC unit that has between 2 and 3 s time on stream, and the fixed bed reactor MAT unit, that has 30 s time on stream.

Dicho S. Stratiev; Ivelina K. Shishkova; Dimitar S. Dobrev

2012-01-01T23:59:59.000Z

22

Different process schemes for converting light straight run and fluid catalytic cracking naphthas in a FCC unit for maximum propylene production  

Science Journals Connector (OSTI)

Light straight run (LSR) and fluid catalytic cracking (FCCN) naphthas were cracked in a transported bed reactor (MicroDowner) and in a fixed bed reactor (MAT) over a commercial Y zeolite based catalyst, over a commercial ZSM-5 zeolite based additive, and over a mixture of both at selected conditions. Based on the mechanisms through which naphtha hydrocarbons are converted, we evaluated the best alternatives for processing these streams to produce light olefins and/or to reduce olefins content in commercial gasoline. The experimental set-up allowed us to simulate the cracking behaviour of the different naphtha streams in a fluid catalytic cracking (FCC) unit by different processing schemes. Results indicate that LSR only cracks at high severity, yielding large amounts of dry gas. Despite its high olefins content, FCCN practically does not crack when it is fed together with gas oil feed. When cracking FCCN alone at typical gas oil cracking conditions, olefins are transformed preferentially into naphtha-range isoparaffins and aromatics, and when cracking FCCN at high severity, olefins are transformed preferentially into propylene and butylenes. Finally, cracking naphtha in the stripper produces some propylene and increases the aromatics in the remaining gasoline.

Avelino Corma; FranciscoV Melo; Laurent Sauvanaud; F.J Ortega

2004-01-01T23:59:59.000Z

23

A probabilistic model to predict the formation and propagation of crack networks in thermal  

E-Print Network [OSTI]

. In the case of cooling systems in nuclear power plants, observations revealed the presence of thermal crazing loading even if thermal fatigue is multiaxial. However, the first simulations on a uniaxial mechanicalA probabilistic model to predict the formation and propagation of crack networks in thermal fatigue

24

Design of a turbomachine set for a fluid catalytic cracking plant and its shop-testing under full-load conditions  

SciTech Connect (OSTI)

In fluid catalytic cracking plants, heavy hydrocarbons are converted into low-boiling point products. Starting from a concise description of the energy recovery system, this paper details the design features of a turbo machine set for an FCC plant, with the emphasis on the design of the four-stage 12,000 kW process gas expander. 6 refs.

Turanskyj, L.; Woelk, G.U.

1982-04-01T23:59:59.000Z

25

Application of Nanotechnology for Heavy Oil Upgrading: Catalytic Steam Gasification/Cracking of Asphaltenes  

Science Journals Connector (OSTI)

It is well-known that oilsands processing and production faces several challenges that need to be surmounted to make it an environmentally sound and economically feasible industry. ... In this work, we are exploring a novel method for the elimination of asphaltenes, waste hydrocarbons, by adsorption on nanoparticles and, subsequent, catalytic steam gasification of the adsorbed asphaltenes for synthesis gas production. ...

Nashaat N. Nassar; Azfar Hassan; Pedro Pereira-Almao

2011-03-21T23:59:59.000Z

26

Improved high efficiency third stage separator cyclones for separation of fines from fluid catalytic cracking flue gas  

SciTech Connect (OSTI)

Stairmand type small diameter (0.254 m) multicyclones were cold flow tested for fluid catalytic cracking third stage separator application. The gas discharge from the cyclone dust outlet into the common collection hopper was found to far exceed the hopper bleed rate (underflow). The excess gas reentrained dust from the hopper back into cyclones, which lowered collection efficiencies. Vortex {open_quotes}stabilization{close_quotes} using apex cones was unsuccessful whereas a Mobil proprietary cyclone modification was successful in minimizing excess gas discharge and dust reentrainment at the cyclone-hopper boundary. In tests at 700 {degrees}C, the modified cyclones captured all particles above 4 {mu}m. Mobil-Kellogg incorporated the modified cyclones in a new third stage separator design which is targeted for achieving lowest opacity and <50 mg/Nm{sup 3} emissions at the stack. The first such unit will be commercialized in Mobil`s newest catalytic cracker (M.W. Kellogg design) under construction in Altona, Australia in late 1996. 5 refs., 4 figs., 2 tabs.

Chitnis, G.K.; Schatz, K.W. [Mobil Technology Co., Paulsboro, NJ (United States); Bussey, B.K. [M.W. Kellogg Co., Houston, TX (United States)

1996-12-31T23:59:59.000Z

27

Thermal resistance of bridged cracks in fiber-reinforced ceramic John Dryden  

E-Print Network [OSTI]

and elasticity in multiphase materials is emphasized. The results for the constriction resistance are comparedThermal resistance of bridged cracks in fiber-reinforced ceramic composites John Dryden Department of Mechanical and Materials Engineering, The University of Western Ontario, London, Ontario, Canada, N6A 5B9

Zok, Frank

28

Modeling the kinetics of parallel thermal and catalytic hydrotreating of heavy oil  

Science Journals Connector (OSTI)

Abstract A series of experiments were performed for obtaining the kinetics of the parallel thermal and catalytic hydrotreating reactions. The reactions considered were: hydrodesulfurization, hydrodenitrogenation (basic and non-basic), hydrodemetallization, hydrodeasphaltenization and hydro Conradson carbon removal. Hydrodesulfurization reaction was described by Langmuir–Hinshelwood kinetics while the other reactions were modeled with power-law approach. The tests were carried out in a CSTBR at the following conditions: 380–420 °C, 9.8 MPa, 891 std m3/m3 of hydrogen-to-oil ratio, 0.98–2.56 of g feed/(g cat h), and 200 h of time-on-stream. The developed kinetic model incorporates the effectiveness factor and a time-dependant deactivation function for obtaining the intrinsic kinetic parameters. It was demonstrated that at low severity reaction conditions the reactions occur via catalytic route, while at high severity conditions thermal reactions are more favored.

Jeremías Martínez; Jorge Ancheyta

2014-01-01T23:59:59.000Z

29

Effect of cracks on the thermal resistance of aligned fiber composites Department of Mechanical and Materials Engineering, University of Western Ontario, London,  

E-Print Network [OSTI]

Effect of cracks on the thermal resistance of aligned fiber composites J. Dryden Department are bridged by the fibers, and this crack- ing causes an increase in the longitudinal thermal resistance of the matrix and the fiber, respectively. The thermal resistance of a pristine unit cell is R0 L b2 kz . 4

Zok, Frank

30

Sulfur distribution in the oil fractions obtained by thermal cracking of Jordanian El-Lajjun oil Shale  

E-Print Network [OSTI]

by the thermal cracking process of the El-Lujjan oil shale showed that the yield of oil was around 12 wt of the boiling point for different distillate fractions. Sulfur in Jordanian oil shale was found to be mainly the dominant phases in these fractions. q 2005 Published by Elsevier Ltd. 1. Introduction Oil shale

Shawabkeh, Reyad A.

31

Thermally activated dislocation creep model for primary water stress corrosion cracking of NiCrFe alloys  

SciTech Connect (OSTI)

There is a growing awareness that awareness that environmentally assisted creep plays an important role in integranular stress corrosion cracking (IGSCC) of NiCrFe alloys in the primary coolant water environment of a pressurized water reactor (PWR). The expected creep mechanism is the thermally activated glide of dislocations. This mode of deformation is favored by the relatively low temperature of PWR operation combined with the large residual stresses that are most often identified as responsible for the SCC failure of plant components. Stress corrosion crack growth rate (CGR) equations that properly reflect the influence of this mechanism of crack tip deformation are required for accurate component life predictions. A phenomenological IGSCC-CGR model, which is based on an apriori assumption that the IGSCC-CGR is controlled by a low temperature dislocation creep mechanism, is developed in this report. Obstacles to dislocation creep include solute atoms such as carbon, which increase the lattice friction force, and forest dislocations, which can be introduced by cold prestrain. Dislocation creep also may be environmentally assisted due to hydrogen absorption at the crack tip. The IGSCC-CGR model developed here is based on an assumption that crack growth occurs by repeated fracture events occurring within an advancing crack-tip creep-fracture zone. Thermal activation parameters for stress corrosion cracking are obtained by fitting the CGR model to IGSCC-CGR data obtained on NiCrFe alloys, Alloy X-750 and Alloy 600. These IGSCC-CGR activation parameters are compared to activation parameters obtained from creep and stress relaxation tests. Recently reported CGR data, which exhibit an activation energy that depends on yield stress and the applied stress intensity factor, are used to benchmark the model. Finally, the effects of matrix carbon concentration, grain boundary carbides and absorbed hydrogen concentration are discussed within context of the model.

Hall, M.M., Jr

1995-12-31T23:59:59.000Z

32

ZSM-5- and MgAl2O4-Based Bifunctional Additives for Enhancing the Production of Propene and Removal of SO2 in the Fluid Catalytic Cracking (FCC) Process  

Science Journals Connector (OSTI)

ZSM-5- and MgAl2O4-Based Bifunctional Additives for Enhancing the Production of Propene and Removal of SO2 in the Fluid Catalytic Cracking (FCC) Process† ... The effects of adding the bifunctional additives containing MgAl2O4 and the commercial propene additive ZSM-5/kaolin to the base catalyst in cracking of vacuum gas oil (VGO) were investigated. ... Those additives adsorb SOx and then transfer sulfur back into the riser, where it is released as H2S, which is removed in the usual way (Claus process). ...

Xiaoling Xu; Xiaoli Ran; Qiukai Cui; Chunyi Li; Honghong Shan

2010-01-26T23:59:59.000Z

33

Effects of thermal aging on Stress Corrosion Cracking and mechanical properties of stainless steel weld metals  

E-Print Network [OSTI]

Stress Corrosion Cracking (SCC) in and around primary loop piping welds in Boiling Water Reactors has been observed worldwide as plants continue to operate at temperatures and pressures near 2880C (5500F) and 6.9 MPa (1000 ...

Hixon, Jeff

2006-01-01T23:59:59.000Z

34

Thermally Coupled Catalytic Reactor for Steam Reforming of Methane and Liquid Hydrocarbons: Experiment and Mathematical Modeling  

Science Journals Connector (OSTI)

An energy-efficient catalytic reactor for producing synthesis gas from methane and liquid hydrocarbons is proposed that is ... on the coupling of an endothermic reaction (steam reforming of methane, hexane, or is...

V. A. Kirillov; N. A. Kuzin; A. V. Kulikov…

2003-05-01T23:59:59.000Z

35

Thermally activated low temperature creep and primary water stress corrosion cracking of NiCrFe alloys  

SciTech Connect (OSTI)

A phenomenological SCC-CGR model is developed based on an apriori assumption that the SCC-CGR is controlled by low temperature creep (LTC). This mode of low temperature time dependent deformation occurs at stress levels above the athermal flow stress by a dislocation glide mechanism that is thermally activated and may be environmentally assisted. The SCC-CGR model equations developed contain thermal activation parameters descriptive of the dislocation creep mechanism. Thermal activation parameters are obtained by fitting the CGR model to SCC-CGR data obtained on Alloy 600 and Alloy X-750. These SCC-CGR activation parameters are compared to LTC activation parameters obtained from stress relaxation tests. When the high concentration of hydrogen at the tip of an SCC crack is considered, the SCC-CGR activation energies and rate sensitivities are shown to be quantitatively consistent with hydrogen reducing the activation energy and increasing the strain rate sensitivity in LTC stress relaxation tests. Stress dependence of SCC-CGR activation energy consistent with that found for the LTC activation energy. Comparisons between temperature dependence of the SCC-CGR stress sensitivity and LTC stress sensitivity provide a basis for speculation on effects of hydrogen and solute carbon on SCC crack growth rates.

Hall, M.M. Jr.

1993-10-01T23:59:59.000Z

36

The evolution of solid density within a thermal explosion II. Dynamic proton radiography of cracking and solid consumption by burning  

SciTech Connect (OSTI)

We report proton transmission images obtained subsequent to the laser assisted thermal ignition of a sample of PBX 9501 (a plastic bonded formulation of the explosive nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)). We describe the laser assisted thermal ignition technique as a means to synchronize a non-linear thermal ignition event while preserving the subsequent post-ignition behavior. We have obtained dynamic proton transmission images at two spatial magnifications and viewed both the radial and transverse axis of a solid cylindrical sample encased in aluminum. Images have been obtained with 3 to 15 {mu}s temporal resolution and approximately 100 {mu}m spatial resolution at the higher magnification. We observe case expansion from very early in the experiment, until case fragmentation. We observe spatially anisotropic features in the transmission which we attribute to cracking in the solid explosive, in agreement with previous measurements conducted on two dimensional samples with optical viewing. Digital analysis of the images also reveals spatially isotropic features which we attribute to the evolution of the loss of density by burning subsequent to thermal ignition.

Smilowitz, L.; Henson, B. F.; Romero, J. J.; Asay, B. W.; Saunders, A.; Merrill, F. E.; Morris, C. L.; Kwiatkowski, K.; Grim, G.; Mariam, F.; Schwartz, C. L.; Hogan, G.; Nedrow, P.; Murray, M. M.; Thompson, T. N.; Espinoza, C.; Lewis, D.; Bainbridge, J.; McNeil, W.; Rightley, P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); and others

2012-05-15T23:59:59.000Z

37

Effect of thermal treatment on coke reactivity and catalytic iron mineralogy  

SciTech Connect (OSTI)

Iron minerals in coke can catalyze its gasification and may affect coke behavior in the blast furnace. The catalytic behavior of iron depends largely upon the nature of the iron-bearing minerals. To determine the mineralogical changes that iron could undergo in the blast furnace, cokes made from three coals containing iron present in different mineral forms (clays, carbonates, and pyrite) were examined. All coke samples were heat-treated in a horizontal furnace at 1373, 1573, and 1773 K and then gasified with CO{sub 2} at 1173 K in a fixed bed reactor (FBR). Coke mineralogy was characterized using quantitative X-ray diffraction (XRD) analysis of coke mineral matter prepared by low-temperature ashing (LTA) and field emission scanning electron microscopy combined with energy dispersive X-ray analysis (FESEM/EDS). The mineralogy of the three cokes was most notably distinguished by differing proportions of iron-bearing phases. During heat treatment and subsequent gasification, iron-containing minerals transformed to a range of minerals but predominantly iron-silicides and iron oxides, the relative amounts of which varied with heat treatment temperature and gasification conditions. The relationship between initial apparent reaction rate and the amount of catalytic iron minerals - pyrrhotite, metallic iron, and iron oxides - was linear and independent of heat treatment temperature at total catalyst levels below 1 wt %. The study showed that the coke reactivity decreased with increasing temperature of heat treatment due to decreased levels of catalytic iron minerals (largely due to formation of iron silicides) as well as increased ordering of the carbon structure. The study also showed that the importance of catalytic mineral matter in determining reactivity declines as gasification proceeds. 37 refs., 13 figs., 7 tabs.

Byong-chul Kim; Sushil Gupta; David French; Richard Sakurovs; Veena Sahajwalla [University of New South Wales, Sydney, NSW (Australia). Centre for Sustainable Materials Research and Technology

2009-07-15T23:59:59.000Z

38

Enhanced thermal and gas flow performance in a three-way catalytic converter through use of insulation within the ceramic monolith  

Broader source: Energy.gov [DOE]

Emissions performance comparison of conventional catalytic converter with multi-channel catalytic converter (ceramic fiber insulation layers introduced into ceramic monolith of three-way catalytic converter)

39

Catalytic reactor  

DOE Patents [OSTI]

A catalytic reactor is provided with one or more reaction zones each formed of set(s) of reaction tubes containing a catalyst to promote chemical reaction within a feed stream. The reaction tubes are of helical configuration and are arranged in a substantially coaxial relationship to form a coil-like structure. Heat exchangers and steam generators can be formed by similar tube arrangements. In such manner, the reaction zone(s) and hence, the reactor is compact and the pressure drop through components is minimized. The resultant compact form has improved heat transfer characteristics and is far easier to thermally insulate than prior art compact reactor designs. Various chemical reactions are contemplated within such coil-like structures such that as steam methane reforming followed by water-gas shift. The coil-like structures can be housed within annular chambers of a cylindrical housing that also provide flow paths for various heat exchange fluids to heat and cool components.

Aaron, Timothy Mark (East Amherst, NY); Shah, Minish Mahendra (East Amherst, NY); Jibb, Richard John (Amherst, NY)

2009-03-10T23:59:59.000Z

40

Thermal decomposition of ethanol and growth of vertically aligned single-walled carbon nanotubes by alcohol catalytic chemical vapor deposition  

E-Print Network [OSTI]

Thermal decomposition of ethanol and growth of vertically aligned single-walled carbon nanotubes. In this study, we have investigated the thermal decomposition of ethanol at various temperatures, as well National Meeting, San Francisco, CA, September 10-14, 2006 1/1 PRES 29 - Thermal decomposition of ethanol

Maruyama, Shigeo

Note: This page contains sample records for the topic "thermal catalytic cracking" 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

Regenerative catalytic oxidation  

SciTech Connect (OSTI)

Currently Regenerative Thermal Oxidizers (R.T.O.`s) are an accepted technology for the control of volatile organic compounds (VOC`s) and hazardous air pollutants (HAP`s). This control technology, when introduced, offered substantial reductions in operating costs, especially auxiliary fuel requirements when compared to existing control technologies such as recuperative thermal and recuperative catalytic oxidizers. While these savings still exist, there is a demand for control of new and/or hybrid technologies, one of which is Regenerative Catalytic Oxidizers (R.C.O.`s). This paper will explore the development of regenerative catalytic oxidation from the theoretical stage through pilot testing through a commercial installation. The operating cost of R.C.O.`s will be compared to R.T.O.`s to verify the savings that are achievable through the use of regenerative catalytic oxidation. In the development of this technology, which is a combination of two (2) existing technologies, R.T.O.`s and catalysis, a second hybrid technology was explored and pilot tested. This is a combination R.C.O. for VOC and HAP control and simultaneous SCR (Selective Catalytic Reduction) for NOx (Oxides of Nitrogen) control. Based on the pilot and full scale testing, both regenerative catalytic oxidizers and systems which combine R.C.O. with SCR for both VOC and NOx reduction are economically viable and are in fact commercially available. 6 figs., 2 tabs.

Gribbon, S.T. [Engelhard Process Emission Systems, South Lyon, MI (United States)

1996-12-31T23:59:59.000Z

42

Materials Science and Engineering A 490 (2008) 2635 Mechanisms of cracking and delamination within thick thermal barrier  

E-Print Network [OSTI]

. Introduction The maximum temperature capability of thermal barrier systems used in gas turbines is often that characterizes the susceptibility to delamination of thermal barrier coated (TBC) hot-section aero-turbine and sub-surface delaminations, as well as spalls. Estimates of the residual stress gradients made on cross

Hutchinson, John W.

43

Carbenium ion intermediates in catalytic cracking  

E-Print Network [OSTI]

polymerization for which carbenium ions are proposed intermediates. In order to increase the signal amplitude, propene 2-13C (99. 2% enriched) was used as the adsorbate. The results of these experiments indicate that carbe- nium ions are in fact... C, (d) 300 C, (e) 400 C C HNR spectra of sec-butyl chloride antimony pentafluoride mixture 16 13C NMR spectrum of C- ethene on H-ZSN5 . . . . 19 C CPNAS spectrum of tri-phenylmethyl chloride adsorbed on silica-alumina Schematic representation...

Zardkoohi, Minoo

2012-06-07T23:59:59.000Z

44

Fluid Catalytic Cracking Power Recovery Computer Simulation  

E-Print Network [OSTI]

re covery available in new plants results in the air string being almost self sustaining, 8S far as direct input power. With some processes, it is possible to produce excess power on the order of 1,000 to 9,000 HP. Waste heat recovery in the form...

Samurin, N. A.

1979-01-01T23:59:59.000Z

45

Thermal decomposition of Cu-based hydroxycarbonate catalytic precursors for the low-temperature co-shift reaction  

Science Journals Connector (OSTI)

The thermal decomposition of Cu-Zn-Al hydroxycarbonate precursors to obtain water-gas shift catalysts was studied by employing a variety of experimental techniques. A set of six samples containing 34 wt% of Cu an...

M. J. L. Ginés; C. R. Apesteguía

1997-12-01T23:59:59.000Z

46

Combustion in cracks of PBX 9501  

SciTech Connect (OSTI)

Recent experiments involving the combustion of PBX 9501 explosive under confined conditions reveal the importance of crack and flaws in reaction violence. Experiments on room temperature confined disks of pristine and thermally damaged PBX 9501 reveal that crack ignition depends on hot gases entering existing or pressure induced cracks rather than on energy release at the crack tip. PBX 9501 slot combustion experiments show that the reaction propagation rate in the slot does not depend on the external pressure. We have observed 1500 d s in long slots of highly-confined PBX 9501. We present experiments that examine the combustion of mechanically and thermally damaged samples of PBX 9501.

Berghout, H. L. (Henry L.); Son, S. F. (Steven F.); Bolme, C. A. (Cynthia A.); Hill, L. G. (Larry G.); Asay, B. W. (Blaine W.); Dickson, P. M. (Peter M.); Henson, B. F. (Bryan F.); Smilowitz, L. B. (Laura B.)

2002-01-01T23:59:59.000Z

47

Cracking knuckles  

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

Cracking knuckles Cracking knuckles Name: Renee Knuckles Location: N/A Country: N/A Date: N/A Question: Does cracking your joints especially the knuckles cause arthritis? What are some of the results of doing so? Replies: Cracking knuckles has NEVER been associated with causing arthritis. This concept is as wrong as saying weight lifting makes you short, or playing basketball makes you tall. The "popping" of the knuckles results from forcing joint fluid to very rapidly pass from one side of the joint to the other, where the "sides" are partitioned off by the main bones of the joint. Let me rephrase that: a joint is an area where two or more separate and distinct bones meet. The joint fluid provides a cushioning between the joints so that they don't grate into each other. Cracking your knuckles forces the joint fluid from one part of the joint to another, and the popping sound is just the result of the high pressured rushing of fluid.

48

Thermal Cracking of Higher Paraffins  

Science Journals Connector (OSTI)

The model was based on the Kossiakoff and Rice theory, that is, including the following five elementary reactions:? initiation, ... ...

H. H. Voge; G. M. Good

1949-02-01T23:59:59.000Z

49

CATALYTIC BIOMASS LIQUEFACTION  

E-Print Network [OSTI]

LBL-11 019 UC-61 CATALYTIC BIOMASS LIQUEFACTION Sabri Ergun,Catalytic Liquefaction of Biomass,n M, Seth, R. Djafar, G.of California. CATALYTIC BIOMASS LIQUEFACTION QUARTERLY

Ergun, Sabri

2013-01-01T23:59:59.000Z

50

Catalytic Coherence  

Science Journals Connector (OSTI)

Because of conservation of energy we cannot directly turn a quantum system with a definite energy into a superposition of different energies. However, if we have access to an additional resource in terms of a system with a high degree of coherence, as for standard models of laser light, we can overcome this limitation. The question is to what extent coherence gets degraded when utilized. Here it is shown that coherence can be turned into a catalyst, meaning that we can use it repeatedly without ever diminishing its power to enable coherent operations. This finding stands in contrast to the degradation of other quantum resources and has direct consequences for quantum thermodynamics, as it shows that latent energy that may be locked into superpositions of energy eigenstates can be released catalytically.

Johan Åberg

2014-10-07T23:59:59.000Z

51

Cracking of Composite Modified Alloy 825 Primary Air Port Tubes  

SciTech Connect (OSTI)

Twenty primary air ports fabricated from modified Alloy 825-based composite tubes underwent a metallurgical examination to document the mode and extent of cracking on the external fireside surface of a kraft recovery boiler. Collectively, the crack features found are most consistent with thermal fatigue, but corrosion fatigue cannot be ruled out. Regardless of the true cracking mechanism, temperature cycling is implicated as a critical factor for crack propagation. on the basis of the relative crack lengths observed, membrane welds and tube weld repairs, and their adjacent heat-affected zones, appear to be more susceptible to cracking than the cladding itself. This work suggests that mills should avoid boiler operating conditions that promote large temperature fluctuations, which can cause Alloy 825-based composite tubes to crack.

Kish, Joseph R. [Paprican; Keiser, James R [ORNL; Singbeil, Douglas [Paprican; Willoughby, Adam W [ORNL; Longmire, Hu Foster [ORNL

2007-04-01T23:59:59.000Z

52

CATALYTIC LIQUEFACTION OF BIOMASS  

E-Print Network [OSTI]

liquid Fuels from Biomass: "Catalyst Screening and KineticUC-61 (l, RCO osn CDL or BIOMASS CATALYTIC LIQUEFACTION ManuCATALYTIC LIQUEFACTION OF BIOMASS Manu Seth, Roger Djafar,

Seth, Manu

2012-01-01T23:59:59.000Z

53

CATALYTIC BIOMASS LIQUEFACTION  

E-Print Network [OSTI]

Solvent Systems Catalystic Biomass Liquefaction Investigatereactor Product collection Biomass liquefaction process12-13, 1980 CATALYTIC BIOMASS LIQUEFACTION Sabri Ergun,

Ergun, Sabri

2013-01-01T23:59:59.000Z

54

Catalytic Reforming Downstream Processing of Fresh Feed Input  

U.S. Energy Information Administration (EIA) Indexed Site

Process: Catalytic Reforming Catalytic Cracking Catalytic Hydrocracking Delayed and Fluid Coking Period-Unit: Monthly-Thousand Barrels per Day Annual-Thousand Barrels per Day Process: Catalytic Reforming Catalytic Cracking Catalytic Hydrocracking Delayed and Fluid Coking Period-Unit: Monthly-Thousand Barrels per Day Annual-Thousand Barrels per Day Download Series History Download Series History Definitions, Sources & Notes Definitions, Sources & Notes Show Data By: Process Area Apr-13 May-13 Jun-13 Jul-13 Aug-13 Sep-13 View History U.S. 2,563 2,667 2,739 2,807 2,705 2,609 2010-2013 PADD 1 176 178 180 173 156 167 2010-2013 East Coast 166 164 163 161 140 153 2010-2013 Appalachian No. 1 9 14 16 12 15 14 2010-2013 PADD 2 642 638 668 695 677 615 2010-2013 Ind., Ill. and Ky. 426 411 426 460 450 399 2010-2013 Minn., Wis., N. Dak., S. Dak. 67 62 70 72 72 57 2010-2013 Okla., Kans., Mo.

55

Energy Conservation Revamps in Fluid Catalytic Cracking Systems  

E-Print Network [OSTI]

and product recovery through revamping. Older FCCU designs did not take full advantage of the heat available in the main fractionator. These older designs typically reject large amounts of heat to air or water cooling while using steam to reboil towers...

Wilson, J. W.; Sloan, H. D.

1984-01-01T23:59:59.000Z

56

Rich catalytic injection  

DOE Patents [OSTI]

A gas turbine engine includes a compressor, a rich catalytic injector, a combustor, and a turbine. The rich catalytic injector includes a rich catalytic device, a mixing zone, and an injection assembly. The injection assembly provides an interface between the mixing zone and the combustor. The injection assembly can inject diffusion fuel into the combustor, provides flame aerodynamic stabilization in the combustor, and may include an ignition device.

Veninger, Albert (Coventry, CT)

2008-12-30T23:59:59.000Z

57

Cumene by catalytic distillation  

SciTech Connect (OSTI)

Catalytic distillation, a combination of catalytic reaction and distillation in a single column, has several advantages when used in a process to make cumene from benzene and propylene. An extremely high purity cumene is obtained in high yield. The catalytic distillation principle was used in an earlier process to make MTBE. A unit, started up up in Houston refinery in 1981, operated successfully for four years. Since then, three other MTBE units of this design have gone into service.

Shoemaker, J.D.; Jones, E.M. Jr.

1987-06-01T23:59:59.000Z

58

Solar reforming of methane in a direct absorption catalytic reactor on a parabolic dish  

SciTech Connect (OSTI)

The concept of solar driven chemical reactions in a commercial-scale volumetric receiver/reactor on a parabolic concentrator was successfully demonstrated in the CAtalytically Enhanced Solar Absorption Receiver (CAESAR) test. Solar reforming of methane (CH{sub 4}) with carbon dioxide (CO{sub 2}) was achieved in a 64-cm diameter direct absorption reactor on a parabolic dish capable of 150 kW solar power. The reactor was a catalytic volumetric absorber consisting of a multi-layered, porous alumina foam disk coated with rhodium (Rh) catalyst. The system was operated during both steady-state and solar transient (cloud passage) conditions. The total solar power absorbed reached values up to 97 kW and the maximum methane conversion was 70%. Receiver thermal efficiencies ranged up to 85% and chemical efficiencies peaked at 54%. The absorber performed satisfactorily in promoting the reforming reaction during the tests without carbon formation. However, problems of cracking and degradation of the porous matrix, nonuniform dispersion of the Rh through the absorber, and catalyst deactivation due to sintering and possible encapsulation, must be resolved to achieve long-term operation and eventual commercialization. 17 refs., 11 figs., 1 tab.

Muir, J.F.; Hogan, R.E. Jr.; Skocypec, R.D. (Sandia National Labs., Albuquerque, NM (USA)); Buck, R. (Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Stuttgart (Germany, F.R.). Inst. fuer Technische Thermodynamik)

1990-01-01T23:59:59.000Z

59

Catalytic distillation structure  

SciTech Connect (OSTI)

Catalytic distillation structure for use in reaction distillation columns, a providing reaction sites and distillation structure and consisting of a catalyst component and a resilient component intimately associated therewith. The resilient component has at least about 70 volume % open space and being present with the catalyst component in an amount such that the catalytic distillation structure consist of at least 10 volume % open space.

Smith, Jr., Lawrence A. (Bellaire, TX)

1984-01-01T23:59:59.000Z

60

Elevated temperature crack propagation  

SciTech Connect (OSTI)

This paper is a summary of two NASA contracts on high temperature fatigue crack propagation in metals. The first evaluated the ability of fairly simple nonlinear fracture parameters to correlate crack propagation. Hastelloy-X specimens were tested under isothermal and thermomechanical cycling at temperatures up to 980 degrees C (1800 degrees F). The most successful correlating parameter was the crack tip opening displacement derived from the J-integral. The second evaluated the ability of several path-independent integrals to correlate crack propagation behavior. Inconel 718 specimens were tested under isothermal, thermomechanical, temperature gradient, and creep conditions at temperatures up to 650 degrees C (1200 degrees F). The integrals formulated by Blackburn and by Kishimoto correlated the data reasonably well under all test conditions.

Orange, T.W.

1994-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal catalytic cracking" 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

Evaluation of cracking in steam generator feedwater piping in pressurized water reactor plants  

SciTech Connect (OSTI)

Cracking in feedwater piping was detected near the inlet to steam generators in 15 pressurized water reactor plants. Sections with cracks from nine plants are examined with the objective of identifying the cracking mechanism and assessing various factors that might contribute to this cracking. Using transmission electron microscopy, fatigue striations are observed on replicas of cleaned crack surfaces. Calculations based on the observed striation spacings gave a cyclic stress value of 150 MPa (22 ksi) for one of the major cracks. The direction of crack propagation was invariably related to the piping surface and not to the piping axis. These two factors are consistent with the proposed concept of thermally induced, cyclic, tensile surface stresses and it is concluded that the overriding factor in the cracking problem was the presence of such undocumented cyclic loads.

Goldberg, A.; Streit, R.D.

1981-05-01T23:59:59.000Z

62

VOC Destruction by Catalytic Combustion Microturbine  

SciTech Connect (OSTI)

This project concerned the application of a catalytic combustion system that has been married to a micro-turbine device. The catalytic combustion system decomposes the VOC's and transmits these gases to the gas turbine. The turbine has been altered to operate on very low-level BTU fuels equivalent to 1.5% methane in air. The performance of the micro-turbine for VOC elimination has some flexibility with respect to operating conditions, and the system is adaptable to multiple industrial applications. The VOC source that was been chosen for examination was the emissions from coal upgrading operations. The overall goal of the project was to examine the effectiveness of a catalytic combustion based system for elimination of VOCs while simultaneously producing electrical power for local consumption. Project specific objectives included assessment of the feasibility for using a Flex-Microturbine that generates power from natural gas while it consumes VOCs generated from site operations; development of an engineering plan for installation of the Flex-Microturbine system; operation of the micro-turbine through various changes in site and operation conditions; measurement of the VOC destruction quantitatively; and determination of the required improvements for further studies. The micro-turbine with the catalytic bed worked effectively to produce power on levels of fuel much lower than the original turbine design. The ability of the device to add or subtract supplemental fuel to augment the amount of VOC's in the inlet air flow made the device an effective replacement for a traditional flare. Concerns about particulates in the inlet flow and the presence of high sulfur concentrations with the VOC mixtures was identified as a drawback with the current catalytic design. A new microturbine design was developed based on this research that incorporates a thermal oxidizer in place of the catalytic bed for applications where particulates or contamination would limit the lifetime of the catalytic bed.

Tom Barton

2009-03-10T23:59:59.000Z

63

Catalytic distillation process  

DOE Patents [OSTI]

A method is described for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C[sub 4] feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

Smith, L.A. Jr.

1982-06-22T23:59:59.000Z

64

Catalytic distillation process  

DOE Patents [OSTI]

A method for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C.sub.4 feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

Smith, Jr., Lawrence A. (Bellaire, TX)

1982-01-01T23:59:59.000Z

65

Catalytic Combustion Processes  

Science Journals Connector (OSTI)

This work presents experimental data on the effect of catalytic additives on the combustion characteristics of ammonium nitrate and perchlorate and the explosives of different classes. Burning rates are determ...

A. P. Glaskova

1991-01-01T23:59:59.000Z

66

PHYSICAL REVIEW E 84, 036104 (2011) Average crack-front velocity during subcritical fracture propagation in a heterogeneous medium  

E-Print Network [OSTI]

PHYSICAL REVIEW E 84, 036104 (2011) Average crack-front velocity during subcritical fracture]. In consequence the slow kinetic crack propagation is usually referred to as subcritical crack growth or the subcritical regime. Statistical physics models suggest that this subcritical regime is governed by a thermally

Schmittbuhl, Jean

67

ensl-00156750,version1-22Jun2007 A dynamical law for slow crack growth in polycarbonate films  

E-Print Network [OSTI]

that subcritical crack growth in paper sheets can be successfully described by a thermally activated mechanismensl-00156750,version1-22Jun2007 A dynamical law for slow crack growth in polycarbonate films: 24 juin 2007) We study experimentally the slow growth of a single crack in polycarbonate films

Paris-Sud XI, Université de

68

Catalytic distillation structure  

DOE Patents [OSTI]

Catalytic distillation structure is described for use in reaction distillation columns, and provides reaction sites and distillation structure consisting of a catalyst component and a resilient component intimately associated therewith. The resilient component has at least about 70 volume % open space and is present with the catalyst component in an amount such that the catalytic distillation structure consists of at least 10 volume % open space. 10 figs.

Smith, L.A. Jr.

1984-04-17T23:59:59.000Z

69

Fundamentals of Petroleum Residue Cracking Gasification for Coproduction of Oil and Syngas  

Science Journals Connector (OSTI)

Fundamentals of Petroleum Residue Cracking Gasification for Coproduction of Oil and Syngas ... Thus, the terminology of heavy oil or heavy residue can be also used to indicate all such heavy petroleum oils. ... Notwithstanding, for the RCG process it is ideal to develop the catalyst that has moderate cracking activity for heavy residues or heavy oils but meanwhile good activity for catalyzing the deposited coke gasification so that the gasification can be at reasonably low temperatures to maintain the catalytic activity for cracking heavy fractions. ...

Yuming Zhang; Deping Yu; Wangliang Li; Yin Wang; Shiqiu Gao; Guangwen Xu

2012-10-23T23:59:59.000Z

70

Crack propagation in Hastelloy X  

SciTech Connect (OSTI)

The fatigue and creep crack growth rates of Hastelloy X were examined both in air and impure helium. Creep crack growth rate is higher in air and impure helium at 650/sup 0/C. Initial creep crack growth from the original sharp fatigue crack is by an intergranular mode of fracture. As the cracking accelerates at higher stress intensities, growth is by a mixed mode of both intergranular and transgranular fracture. Fatigue crack growth rate increases with increasing temperature and decreasing frequency for the range of stress intensities reported in the literature and is lower in impure helium than in air.

Weerasooriya, T.; Strizak, J.P.

1980-05-01T23:59:59.000Z

71

Crack Fundamental Element (CFE) for Multi-scale Crack Classification  

Science Journals Connector (OSTI)

With the advance of sensor and information technology, high-resolution 2D image and 3D range data are available to support crack classification. However, crack classification still remains a challenge because sta...

Yuchun Huang; Yichang (James) Tsai

2012-01-01T23:59:59.000Z

72

Catalytic nanoporous membranes  

DOE Patents [OSTI]

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

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

2013-08-27T23:59:59.000Z

73

Catalytic Solutions Inc CSI | Open Energy Information  

Open Energy Info (EERE)

Developer of the breakthrough catalytic coating technology and the Mixed Phase Catalyst (MPCTM), and also manufacturer of catalytic converters. References: Catalytic...

74

Reflective Cracking Study: Summary Report  

E-Print Network [OSTI]

Cracking Study: First-level Report on Laboratory ShearStudy: Second-Level Analysis Report. Davis and Berkeley, CA:Cracking Study: First-level Report on HVS Testing on Section

Jones, David; Harvey, John T; Monismith, Carl L.

2008-01-01T23:59:59.000Z

75

Catalytic Coal Gasification Process  

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

Catalytic Coal Gasification Process Catalytic Coal Gasification Process for the Production of Methane-Rich Syngas Opportunity Research is active on the patent pending technology, titled "Production of Methane-Rich Syngas from Fuels Using Multi-functional Catalyst/Capture Agent." This technology is available for licensing and/or further collaborative research from the U.S. Department of Energy's National Energy Technology Laboratory. Overview Reducing pollution emitted by coal and waste power plants in an economically viable manner and building power plants that co-generate fuels and chemicals during times of low electricity demand are pressing goals for the energy industry. One way to achieve these goals in an economically viable manner is through the use of a catalytic gasifier that

76

Acidity and catalytic activity of zeolite catalysts bound with silica and alumina  

E-Print Network [OSTI]

. Micropore surface area and micropore volume are reduced by about 19% and 18%, respectively, indicating some micropores of ZSM-5 are blocked on binding with silica. SiO2-bound ZSM-5 catalysts have less catalytic activity for butane transformation (cracking...

Wu, Xianchun

2004-09-30T23:59:59.000Z

77

Analysis of composite tube cracking in recovery boiler floors  

SciTech Connect (OSTI)

Cracking of co-extruded (generally identified as composite) floor tubes in kraft black liquor recovery boilers was first observed in Scandinavia, but this problem has now been found in many North American boilers. In most cases, cracking in the outer 304L stainless steel has not progressed into the carbon steel, but the potential for such crack propagation is a cause of concern. A multidimensional study has been initiated to characterize the cracking seen in composite floor tubes, to measure the residual stresses resulting from composite tube fabrication, and to predict the stresses in tubes under operating conditions. The characterization studies include review of available reports and documents on composite tube cracking, metallographic examination of a substantial number of cracked tubes, and evaluation of the dislocation structure in cracked tubes. Neutron and X-ray diffraction are being used to determine the residual stresses in composite tubes from two major manufacturers, and finite element analysis is being used to predict the stresses in the tubes during normal operation and under conditions where thermal fluctuations occur.

Keiser, J.R.; Taljat, B.; Wang, X.L.; Maziasz, P.J.; Hubbard, C.R.; Swindeman, R.W. [Oak Ridge National Lab., TN (United States); Singbeil, D.L.; Prescott, R. [Pulp and Paper Research Inst. of Canada, Vancouver, British Columbia (Canada)

1996-08-01T23:59:59.000Z

78

The reaction kinetics of gasoline sulfur compounds: Catalytic mechanisms for sulfur reduction  

SciTech Connect (OSTI)

One of the key elements of reformulated gasoline is the reduction of the sulfur compounds produced by fluid catalytic cracking. This paper probes the reaction kinetics of refractory gasoline-range thiophene derivatives (thiophene, tetrahydrothiophene, and alkylthiophenes) in an effort to determine the mechanisms of sulfur compound cracking in the FCC unit. The gasoline-range sulfur compounds were analyzed using gas chromatography with an atomic emission detector. The authors` results show that the FCC catalysts affects the cracking of sulfur compounds through both hydrogen transfer and zeolite pore restriction mechanisms. An experimental FCC catalyst is shown to reduce gasoline sulfur content in the Davidson Circulating Riser (DCR{sup TM}) pilot unit. Model compound tests show that the activity of the catalyst is due to both its catalytic and adsorptive properties. Tetrahydrothiophene, which is produced from thiophenes by hydrogen transfer, is completely removed by the experimental catalyst.

Harding, R.H.; Gatte, R.R.; Albro, T.G.; Wormsbecher, R.F. [W.R. Grace & Co. Conn, Columbia, MD (United States)

1993-12-31T23:59:59.000Z

79

Subcritical crack growth in fibrous materials  

E-Print Network [OSTI]

We present experiments on the slow growth of a single crack in a fax paper sheet submitted to a constant force $F$. We find that statistically averaged crack growth curves can be described by only two parameters : the mean rupture time $\\tau$ and a characteristic growth length $\\zeta$. We propose a model based on a thermally activated rupture process that takes into account the microstructure of cellulose fibers. The model is able to reproduce the shape of the growth curve, the dependence of $\\zeta$ on $F$ as well as the effect of temperature on the rupture time $\\tau$. We find that the length scale at which rupture occurs in this model is consistently close to the diameter of cellulose microfibrils.

Santucci, Stéphane; Deschanel, Stéphanie; Vanel, Loic; Ciliberto, Sergio

2006-01-01T23:59:59.000Z

80

11 - Stresses due to Change of Air Temperature and Superficial Thermal Insulation  

Science Journals Connector (OSTI)

Experience shows that most cracks in mass concrete structures are originally superficial cracks, but some of them may become larger and deeper cracks later on which will reduce the safety and durability of the structure. Thermal insulation is the most efficient measure for preventing superficial cracks of mass concrete structures.

Zhu Bofang

2014-01-01T23:59:59.000Z

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


81

An atomic-scale analysis of catalytically-assisted chemical vapor deposition of carbon nanotubes  

E-Print Network [OSTI]

An atomic-scale analysis of catalytically-assisted chemical vapor deposition of carbon nanotubes M Growth of carbon nanotubes during transition-metal particles catalytically-assisted thermal decomposition of various nanotube surface and edge reactions (e.g. adsorption of hydrocarbons and hydrogen onto the surface

Grujicic, Mica

82

Micro Catalytic Combustor with Pd/Nano-porous Alumina for High-Temperature Application  

E-Print Network [OSTI]

, the mixture temperature at the combustor inlet is set to 630 o C. Thermal conductivity of the ceramic wall Keywords: Catalytic combustion, Pd/nano-porous alumina, Ceramic tape casting, Thermophotovoltaic Abstract: A micro-scale catalytic combustor using high-precision ceramic tape-casting technology has been developed

Kasagi, Nobuhide

83

CSD: Research: Catalytic Science  

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

Catalytic Science Catalytic Science The DOE Chemical Energy program supports basic research in the area of chemical transformations or conversions which are fundamental to new or existing concepts of energy production and storage. A further goal of the program is to identify and develop environmentally benign approaches to the synthesis of chemicals via routes requiring a minimal consumption of energy. These objectives lead naturally to an emphasis on catalysis. Novel homogeneous and heterogeneous catalysts are constantly being sought to enable the synthesis of desired products from nontraditional reactants, often with the aim of minimizing the production of toxic intermediates or byproducts, or to enable the more efficient production of products via existing reaction pathways. To this end, efforts are undertaken to

84

Crack-resistant siloxane molding compounds. [Patent application  

DOE Patents [OSTI]

The crack resistance of phenyl silicone molding resins containing siliceous fillers is improved by incorporating therein about 0.5 to 5.5% by weight of ..beta..-eucryptite, a lithium aluminum silicate having a negative thermal expansion coefficient. These molding resins are particularly suitable for encapsulating electronic devices such as diodes, coils, resistors, and the like.

McFarland, J.W.; Swearngin, C.B.

1980-11-03T23:59:59.000Z

85

The Co-cracking Experiment and Application Route of Waste Plastics and Heavy Oil  

Science Journals Connector (OSTI)

Abstract The co-cracking experiment of waste plastics and heavy oil was done in the condition of 400 °C and pressure not higher than 2.0 MPa. The experimental results showed that the yield of heavy oil and coke decreased but the light oil and gas yield increased with the increasing amount of waste plastics. The products of heavy oil's solidifying point, flash point, viscosity and density decreased and had a good pour point depression effect. Heavy oil containing heat conduction oil and solvent contributed to heat transfer, melting and transport and had the effect of dissolution and co-cracking. It would have a good prospect when the co-cracking of waste plastics and heavy oil was applied to the combination processes of visbreaking and delayed coking and catalytic cracking and delayed coking.

Shikui Wu; Kaixiong Xu; Lusen Jiang; Li Wang

2014-01-01T23:59:59.000Z

86

Status Report on Studies of Recovery Boiler Composite Floor Tube Cracking  

SciTech Connect (OSTI)

Cracking of the stainless steel layer of co-extruded 304L stainless steel/SA210 Gd A 1 carbon steel black liquor recovery boiler floor tubes has been identified as one of the most serious material problems in the pulp and paper industry. A DOE-funded study was initiated in 1995 with the goal of determining the cause of and possible solutions to this cracking problem. These studies have characterized tube cracking as well as the chemical and thermal environment and stress state of floor tubes. Investigations of possible cracking mechanisms indicate that stress corrosion cracking rather than thermal fatigue is a more likely cause of crack initiation. The cracking mechanism appears to require the presence of hydrated sodium sulfide and is most likely active during shut-downs and/or start-ups. Based on these results and operating experience, certain alloys appear to be more resistant than others to cracking in the floor environment, and certain operating practices appear to significantly lessen the likelihood of cracking. This report is the latest in a series of progress reports presented on this project.

Eng, P.; Frederick, L.A.; Hoffmann, C.M.; Keiser, J.R.; Mahmood, J.; Maziasz, P.J.; Prescott, R.; Sarma, G.B.; Singbeil, D.L.; Singh, P.M.; Swindeman, R.W.; Wang, X.-L.

1999-09-12T23:59:59.000Z

87

Catalytic Activity of Alkali Metals on the Thermochemical Conversion of Biomass Materials  

Science Journals Connector (OSTI)

The first reaction in the thermal decomposition of cellulose is very sensitive to the existence of mineral impurities such as alkali metals and iron at concentrations as low as 0.5%. The catalytic reaction app...

Mahmood M. Barbooti

1986-01-01T23:59:59.000Z

88

Catalytic distillation : design and application of a catalytic distillation column.  

E-Print Network [OSTI]

??Catalytic Distillation (CD) is a hybrid technology that utilizes the dynamics of si- multaneous reaction and separation in a single process unit to achieve a… (more)

Nieuwoudt, Josias Jakobus (Jako)

2005-01-01T23:59:59.000Z

89

Identifying and Understanding Environment-Induced Crack propagation Behavior in Ni-based Superalloy INCONEL 617  

SciTech Connect (OSTI)

The nickel-based superalloy INCONEL 617 is a candidate material for heat exchanger applications in the next-generation nuclear plant (NGNP) system. This project will study the crack propagation process of alloy 617 at temperatures of 650°C-950°C in air under static/cyclic loading conditions. The goal is to identify the environmental and mechanical damage components and to understand in-depth the failure mechanism. Researchers will measure the fatigue crack propagation (FCP) rate (da/dn) under cyclic and hold-time fatigue conditions, and sustained crack growth rates (da/dt) at elevated temperatures. The independent FCP process will be identified and the rate-controlled sustained loading crack process will be correlated with the thermal activation equation to estimate the oxygen thermal activation energy. The FCP-dependent model indicates that if the sustained loading crack growth rate, da/dt, can be correlated with the FCP rate, da/dn, at the full time dependent stage, researchers can confirm stress-accelerated grain-boundary oxygen embrittlement (SAGBOE) as a predominate effect. Following the crack propagation tests, the research team will examine the fracture surface of materials in various cracking stages using a scanning electron microscope (SEM) and an optical microscope. In particular, the microstructure of the crack tip region will be analyzed in depth using high resolution transmission electron microscopy (TEM) and electron energy loss spectrum (EELS) mapping techniques to identify oxygen penetration along the grain boundary and to examine the diffused oxygen distribution profile around the crack tip. The cracked sample will be prepared by focused ion beam nanofabrication technology, allowing researchers to accurately fabricate the TEM samples from the crack tip while minimizing artifacts. Researchers will use these microscopic and spectroscopic results to interpret the crack propagation process, as well as distinguish and understand the environment or SAGBOE damage process under hold-time fatigue and sustained loading conditions

Longzhou Ma

2012-11-30T23:59:59.000Z

90

Stress corrosion crack growth in porous sandstones.   

E-Print Network [OSTI]

Stress corrosion crack growth occurs when the chemical weakening of strained crack tip bonds facilitates crack propagation. I have examined the effect of chemical processes on the growth of a creack population by carrying out triaxial compression...

Ojala, Ira O

91

Cumene by Catalytic Distillation  

SciTech Connect (OSTI)

The novel concept of Catalytic Distillation has been commercialized in the CRandL MTBE process, in which combined reaction and distillation provide energy savings over conventional processes. This concept has now been extended to production of cumene from benzene and propylene. In this case the advantages of the technique are not only energy savings but significant reductions in by-product losses and capital requirements. In this paper the development of the process is discussed and the economics of commercial operation are presented.

Jones, E.M.; Mawer, J.

1986-01-01T23:59:59.000Z

92

Novel Catalytic Membrane Reactors  

SciTech Connect (OSTI)

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

Stuart Nemser, PhD

2010-10-01T23:59:59.000Z

93

Effect of Syngas Addition on Lower Alkene Production by the Oxidative Cracking of Hexane  

Science Journals Connector (OSTI)

For the COC of C6 with added syngas, the mechanism of exothermic heterogeneous combustion reactions (e.g., H2?O2 catalytic combustion), followed by endothermic homogeneous pyrolysis reaction of C6, is supposed, in which lower alkenes are produced in the gas-phase cracking of C6, using the heat generated from heterogeneously catalytic combustion reactions. ... Both Sn/SiO2 and PtSn/SiO2 seem to be able to selectively combust hydrogen in a gas mixt. ...

Haiou Zhu; Xuebin Liu; Wenzhao Li; Qingjie Ge; Hengyong Xu

2005-04-21T23:59:59.000Z

94

Discrete Element Model for Simulations of Early-Life Thermal Fracturing Behaviors in Ceramic Nuclear Fuel Pellets  

SciTech Connect (OSTI)

A discrete element Model (DEM) representation of coupled solid mechanics/fracturing and heat conduction processes has been developed and applied to explicitly simulate the random initiations and subsequent propagations of interacting thermal cracks in a ceramic nuclear fuel pellet during initial rise to power and during power cycles. The DEM model clearly predicts realistic early-life crack patterns including both radial cracks and circumferential cracks. Simulation results clearly demonstrate the formation of radial cracks during the initial power rise, and formation of circumferential cracks as the power is ramped down. In these simulations, additional early-life power cycles do not lead to the formation of new thermal cracks. They do, however clearly indicate changes in the apertures of thermal cracks during later power cycles due to thermal expansion and shrinkage. The number of radial cracks increases with increasing power, which is consistent with the experimental observations.

Hai Huang; Ben Spencer; Jason Hales

2014-10-01T23:59:59.000Z

95

Method and apparatus for thermal management of vehicle exhaust systems  

DOE Patents [OSTI]

A catalytic converter is surrounded by variable conductance insulation for maintaining the operating temperature of the catalytic converter at an optimum level, for inhibiting heat loss when raising catalytic converter temperature to light-off temperature, for storing excess heat to maintain or accelerate reaching light-off temperature, and for conducting excess heat away from the catalytic converter after reaching light-off temperature. The variable conductance insulation includes vacuum gas control and metal-to-metal thermal shunt mechanisms. Radial and axial shielding inhibits radiation and convection heat loss. Thermal storage media includes phase change material, and heat exchanger chambers and fluids carry heat to and from the catalytic converter.

Benson, David K. (Golden, CO); Potter, Thomas F. (Denver, CO)

1995-01-01T23:59:59.000Z

96

5, 35333559, 2005 Catalytic conversion  

E-Print Network [OSTI]

measurement technique, employing selective gas- phase catalytic conversion of methanol to formaldehyde it the second most abundant organic trace gas after methane. Methanol can play an important role in upper tropoACPD 5, 3533­3559, 2005 Catalytic conversion of methanol to formaldehyde S. J. Solomon et al. Title

Paris-Sud XI, Université de

97

Analysis of cracking of co-extruded recovery boiler floor tubes  

SciTech Connect (OSTI)

Cracking of the stainless steel layer in co-extruded 304L/SA210 tubing used in black liquor recovery boilers is being found in an ever-increasing number of North American pulp and paper mills. Because of the possibility of a tube failure, this is a significant safety issue, and, because of the extra time required for tube inspection and repair, this can become an economic issue as well. In a project funded by the U.S. Department of Energy and given wide support among paper companies, boiler manufacturers, and tube fabricators, studies are being conducted to determine the cause of the cracking and to identify alternate materials and/or operating procedures to prevent tube cracking. Examination of cracked tubes has permitted characterization of crack features, and transmission electron microscopy is providing information about the thermal history, particularly cyclic thermal exposures, that tubes have experienced. Neutron and x-ray diffraction techniques are being used to determine the residual stresses in as-fabricated tube panels and exposed tubes, and finite element modeling is providing information about the stresses the tubes experience during operation. Laboratory studies are being conducted to determine the susceptibility of the co-extruded 304L/SA210 tubes to stress corrosion cracking, thermal fatigue, and corrosion in molten smelt. This paper presents the current status of these studies. On the basis of all of these studies, recommendations for means to prevent tube cracking will be offered.

Keiser, J.R.; Taljat, B.; Wang, X.L. [and others

1997-08-01T23:59:59.000Z

98

The catalytic activity of Ru and Ir supported on Eu2O3 for the reaction, CO2 + CH4 ? 2 H2 + 2 CO: a viable solar-thermal energy system  

Science Journals Connector (OSTI)

Methane and carbon dioxide which often co-exist in nature, constitute valuable potential resources both for the storage of solar (thermal) energy and the convenient production of synthesis gas....2O3 are effectiv...

J. S. H. Q. Perera; J. W. Couves; G. Sankar; J. M. Thomas

1991-01-01T23:59:59.000Z

99

FOREIGN INVESTMENT: Commerce Cracks Down  

Science Journals Connector (OSTI)

FOREIGN INVESTMENT: Commerce Cracks Down ... U.S. companies "will have to learn to live with" some form of mandatory federal controls on direct overseas investments "for at least a few years." ...

1968-09-02T23:59:59.000Z

100

Peridynamic model for fatigue cracking.  

SciTech Connect (OSTI)

The peridynamic theory is an extension of traditional solid mechanics in which the field equations can be applied on discontinuities, such as growing cracks. This paper proposes a bond damage model within peridynamics to treat the nucleation and growth of cracks due to cyclic loading. Bond damage occurs according to the evolution of a variable called the %22remaining life%22 of each bond that changes over time according to the cyclic strain in the bond. It is shown that the model reproduces the main features of S-N data for typical materials and also reproduces the Paris law for fatigue crack growth. Extensions of the model account for the effects of loading spectrum, fatigue limit, and variable load ratio. A three-dimensional example illustrates the nucleation and growth of a helical fatigue crack in the torsion of an aluminum alloy rod.

Silling, Stewart A.; Abe Askari (Boeing)

2014-10-01T23:59:59.000Z

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


101

Cracking behavior of cored structures  

SciTech Connect (OSTI)

The effects of compositional gradients, are considered based on a thermodynamic analysis, referred to as the Cahn-Hillard analysis, which describes the degree to which a local surface energy is modified by the presence of a composition gradient. The analysis predicts that both ductile and brittle fracture mechanisms are enhanced by the presence of a composition gradient. Data on stress corrosion cracking and fatigue crack growth in selected FCC alloys are used to illustrate the significance of microsegregation on mechanical properties.

Wahid, A.; Olson, D.L.; Matlock, D.K. (Colorado School of Mines, Golden, CO (United States). Center for Welding and Joining Research); Kelly, T.J. (General Electric Aircraft Engines, Evendale, OH (United States))

1991-01-01T23:59:59.000Z

102

Fraunhofer-Center fr Silizium-Photovoltaik CSP CRACK INVESTIGATION OF ENCAPSULATED  

E-Print Network [OSTI]

© Fraunhofer-Center für Silizium-Photovoltaik CSP CRACK INVESTIGATION OF ENCAPSULATED SOLAR CELLS UNDER THERMAL AND MECHANICAL STRESSES Martin Sander Fraunhofer Center for Silicon Photovoltaics CSP-5999, martin.sander@csp.fraunhofer.de Workshop "Impact of mechanical and thermal loads on the long term

103

Development of a catalytically assisted combustor for a gas turbine  

Science Journals Connector (OSTI)

A catalytically assisted low \\{NOx\\} combustor has been developed which has the advantage of catalyst durability. This combustor is composed of a burner section and a premixed combustion section behind the burner section. The burner system consists of six catalytic combustor segments and six premixing nozzles, which are arranged alternately and in parallel. Fuel flow rate for the catalysts and the premixing nozzles are controlled independently. The catalytic combustion temperature is maintained under 1000°C, additional premixed gas is injected from the premixing nozzles into the catalytic combustion gas, and lean premixed combustion at 1300°C is carried out in the premixed combustion section. This system was designed to avoid catalytic deactivation at high temperature and thermal or mechanical shock fracture of the honeycomb monolith. In order to maintain the catalyst temperature under 1000°C, the combustion characteristics of catalysts at high pressure were investigated using a bench scale reactor and an improved catalyst was selected for the combustor test. A combustor for a 20 MW class multi-can type gas turbine was designed and tested under high pressure conditions using LNG fuel. Measurements of NOx, CO and unburned hydrocarbon were made and other measurements were made to evaluate combustor performance under various combustion temperatures and pressures. As a result of the tests, it was proved that \\{NOx\\} emission was lower than 10 ppm converted at 16% O2, combustion efficiency was almost 100% at 1300°C of combustor outlet temperature and 13.5 ata of combustor inlet pressure.

Yasushi Ozawa; Tomoharu Fujii; Mikio Sato; Takaaki Kanazawa; Hitoshi Inoue

1999-01-01T23:59:59.000Z

104

Catalytic steam gasification of coals  

Science Journals Connector (OSTI)

Catalytic steam gasification of coals ... Steam–Coal Gasification Using CaO and KOH for in Situ Carbon and Sulfur Capture ... Steam–Coal Gasification Using CaO and KOH for in Situ Carbon and Sulfur Capture ...

P. Pereira; G. A. Somorjai; H. Heinemann

1992-07-01T23:59:59.000Z

105

Degradation of Structural Alloys Under Thermal Insulation  

E-Print Network [OSTI]

Wet thermal insulation may actively degrade steel and stainless steel structures by general corrosion or stress-corrosion cracking. Two different mechanisms of water ingress into insulation are discussed; flooding from external sources...

McIntyre, D. R.

1984-01-01T23:59:59.000Z

106

The catalytic oxidation of propane  

E-Print Network [OSTI]

THE CATALYTIC OXIDATION OP PROPANE A Thesis By Charles Frederick Sandersont * * June 1949 Approval as to style and content recommended: Head of the Department of Chemical Engineering THE CATALYTICi OXIDATTON OF PROPANE A Thesis By Charles... Frederick ;Sandersonit * June 1949 THE CATALYTIC OXIDATION OP PROPANE A Thesis Submitted to the Faculty of the Agricultural and Mechanical College of Texas in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Major...

Sanderson, Charles Frederick

2013-10-04T23:59:59.000Z

107

Environmental stress cracking of plastics under dynamic conditions  

E-Print Network [OSTI]

The objective of this study was to find out if dynamic conditions have any effect on the phenomenon of environmental stress cracking (ESC). Dynamic conditions in this study include thermal shock, mechanical shock, and vibrations. Injection blow molded... resistance of blow molded polyethylene containers. The experimental data indicated that each of the dynamic conditions accelerated the ESC. Therefore, the results obtained from the static tests cannot be used to predict the service life of the containers...

Suresh, Mitta

1992-01-01T23:59:59.000Z

108

Evaluation of cracking in feedwater piping adjacent to the steam generators in Nine Pressurized Water Reactor Plants  

SciTech Connect (OSTI)

Cracking in ASTM A106-B and A106-C feedwater piping was detected near the inlet to the steam generators in a number of pressurized water reactor plants. We received sections with cracks from nine of the plants with the objective of identifying the cracking mechanism and assessing various factors that might contribute to this cracking. Variations were observed in piping surface irregularities, corrosion-product, pit, and crack morphology, surface elmental and crystal structure analyses, and steel microstructures and mechanical properties. However, with but two exceptions, namely, arrest bands and major surface irregularities, we were unable to relate the extent of cracking to any of these factors. Tensile and fracture toughness (J/sub Ic/ and tearing modulus) properties were measured over a range of temperatures and strain rates. No unusual properties or microstructures were observed that could be related to the cracking problem. All crack surfaces contained thick oxide deposits and showed evidence of cyclic events in the form of arrest bands. Transmission electron microscopy revealed fatigue striations on replicas of cleaned crack surfaces from one plant and possibly from three others. Calculations based on the observed striation spacings gave a value of ..delta..sigma = 150 MPa (22 ksi) for one of the major cracks. The direction of crack propagation was invariably related to the piping surface and not to the piping axis. These two factors are consistent with the proposed concept of thermally induced, cyclic, tensile surface stresses. Although surface irregularities and corrosion pits were sources for crack initiation and corrosion may have contributed to crack propagation, it is proposed that the overriding factor in the cracking problem is the presence of unforeseen cyclic loads.

Goldberg, A.; Streit, R.D.; Scott, R.G.

1980-06-25T23:59:59.000Z

109

Crack propagation driven by crystal growth  

SciTech Connect (OSTI)

Crystals that grow in confinement may exert a force on their surroundings and thereby drive crack propagation in rocks and other materials. We describe a model of crystal growth in an idealized crack geometry in which the crystal growth and crack propagation are coupled through the stress in the surrounding bulk solid. Subcritical crack propagation takes place during a transient period, which may be very long, during which the crack velocity is limited by the kinetics of crack propagation. When the crack is sufficiently large, the crack velocity becomes limited by the kinetics of crystal growth. The duration of the subcritical regime is determined by two non-dimensional parameters, which relate the kinetics of crack propagation and crystal growth to the supersaturation of the fluid and the elastic properties of the surrounding material.

A. Royne; Paul Meaking; A. Malthe-Sorenssen; B. Jamtveit; D. K. Dysthe

2011-10-01T23:59:59.000Z

110

To Crack or Not to Crack: Strain in High Temperature Superconductors  

E-Print Network [OSTI]

Strain in High Temperature Superconductors Arno GodekeCrack: Strain in High Temperature Superconductors MotivationCrack: Strain in High Temperature Superconductors How do Nb

Godeke, Arno

2008-01-01T23:59:59.000Z

111

Catalytic cartridge SO/sub 3/ decomposer  

DOE Patents [OSTI]

A catalytic cartridge surrounding a heat pipe driven by a heat source is utilized as a SO/sub 3/ decomposer for thermochemical hydrogen production. The cartridge has two embodiments, a cross-flow cartridge and an axial flow cartridge. In the cross-flow cartridge, SO/sub 3/ gas is flowed through a chamber and incident normally to a catalyst coated tube extending through the chamber, the catalyst coated tube surrounding the heat pipe. In the axial-flow cartridge, SO/sub 3/ gas is flowed through the annular space between concentric inner and outer cylindrical walls, the inner cylindrical wall being coated by a catalyst and surrounding the heat pipe. The modular cartridge decomposer provides high thermal efficiency, high conversion efficiency, and increased safety. A fusion reactor may be used as the heat source.

Galloway, T.R.

1980-11-18T23:59:59.000Z

112

Nonlinear structural crack growth monitoring  

DOE Patents [OSTI]

A method and apparatus are provided for the detection, through nonlinear manipulation of data, of an indicator of imminent failure due to crack growth in structural elements. The method is a process of determining energy consumption due to crack growth and correlating the energy consumption with physical phenomena indicative of a failure event. The apparatus includes sensors for sensing physical data factors, processors or the like for computing a relationship between the physical data factors and phenomena indicative of the failure event, and apparatus for providing notification of the characteristics and extent of such phenomena.

Welch, Donald E. (Oak Ridge, TN); Hively, Lee M. (Philadelphia, TN); Holdaway, Ray F. (Clinton, TN)

2002-01-01T23:59:59.000Z

113

Intern experience at Fluor Engineers and Constructors, Inc.: an internship report  

E-Print Network [OSTI]

) catalytic cracking, (4) catalytic hydrocracking, (5) alkylation, (6) thermal cracking, (7) hydrotreating, and (8) gas concentration [1:225]. To these primary processes are added auxiliary processes involving treatment units for liquid and gas purification...

Afiesimama, Boma Thompson, 1952-

2013-03-13T23:59:59.000Z

114

Crack propagation in hydrided zircaloy-2  

Science Journals Connector (OSTI)

Transmission electron microscope observations of cracks in thin foils of Zircaloy—2 which contains hydride particles have shown that the fracture process is one of linking up satellite cracks in the hydride ph...

G. Östberg

1968-06-01T23:59:59.000Z

115

Applied Catalysis A: General 192 (2000) 227234 Hydrogen production via the direct cracking of methane over Ni/SiO2  

E-Print Network [OSTI]

of hydrogen and carbon oxides, catalytic cracking produces hy- drogen and solid carbon, thereby eliminating is highly desir- able for use in proton-exchange membrane (PEM) fuel Corresponding author. Fax: +1 be recovered and utilized, this approach can be financially attractive [9]. In our previous work [10] we showed

zur Loye, Hans-Conrad

116

Catalytic distillation extends its reach  

SciTech Connect (OSTI)

Since the early 1980s, catalytic distillation processes have been selected by more than a hundred operators for various applications. Since such a unit performs both reaction and distillation simultaneously, a combined column can replace a separate, fixed-bed reactor and distillation column, thereby eliminating equipment and reducing capital costs. And, compared to the conventional approach, catalytic distillation may also improve other factors, such as reactant conversion, selectivity, mass transfer, operating pressure, oligomer formation and catalyst fouling. The constant washing of the catalyst by liquid flowing down the column and the distillation of high-boiling foulants results in extended catalyst life. Four selective hydrogenation applications of catalytic distillation are discussed: Butadiene selective hydrogenation combined within an MTBE unit; Pentadiene selective hydrogenation; C{sub 4} acetylene conversion; and Benzene saturation.

Rock, K.; McGuirk, T. [Catalytic Distillation Technologies, Houston, TX (United States); Gildert, G.R. [Catalytic Distillation Technologies, Pasadena, TX (United States)

1997-07-01T23:59:59.000Z

117

Cracking of simulated oil refinery off-gas over a coal char, petroleum coke, and quartz  

SciTech Connect (OSTI)

The cracking of oil refinery off-gas, simulated with a gas mixture containing methane (51%), ethylene (21.4%), ethane (21.1%), and propane (6.5%), over a coal char, petroleum coke, and quartz, respectively, has been studied in a fixed bed reactor. The experiments were performed at temperatures between 850 and 1000{sup o}C and at atmospheric pressure. The results show that the conversions of all species considered increased with increasing temperature. Ethane and propane completely decomposed over all three bed materials in the temperature range investigated. However, the higher initial conversion rates of methane and ethylene cracking at all temperatures were observed only over the coal char and not on the petroleum coke and quartz, indicating a significant catalytic effect of the coal char on methane and ethylene cracking. Methane and ethylene conversions decreased with reaction time due to deactivation of the coal char by carbon deposition on the char surface and, in the later stage of a cracking experiment, became negative, suggesting that methane and ethylene had been formed during the cracking of ethane and propane. 16 refs., 13 figs., 2 tabs.

Yuan Zhang; Jin-hu Wu; Dong-ke Zhang [Chinese Academy of Sciences, Taiyuan (China). Institute of Coal Chemistry

2008-03-15T23:59:59.000Z

118

A Kinetic model of crack fusion  

Science Journals Connector (OSTI)

......Research Note A Kinetic model of crack fusion Zbigniew Czechowski Institute of Geophysics...presents a kinetic approach to the problem of fusion of cracks. A kinetic equation for the...repetitive episodes of seismicity. crack fusion|kinetic model|seismicity| References......

Zbigniew Czechowski

1991-02-01T23:59:59.000Z

119

Thermal treatment for VOC control  

SciTech Connect (OSTI)

Catalytic and thermal oxidation are well-established technologies for controlling volatile organic compounds (VOCs). Oxidation destroys pollutants, rather than capturing them. Oxidation units can destroy nearly 100% of VOC and toxic emissions targeted by the Clean Air Act Amendments of 1990--some systems attain destruction efficiencies over 99.99%. To assist in the design of these systems, an engineer will often look a/t the heat of combustion of the gas stream, along with the type of pollutant, to best determine the correct type of oxidation device to use. The paper discusses catalytic and thermal oxidation, energy recovery, and equipment for these processes.

Cloud, R.A. [Huntington Environmental Systems, Schaumburg, IL (United States)

1998-07-01T23:59:59.000Z

120

Catalytic gasification of automotive shredder residues with hydrogen generation  

Science Journals Connector (OSTI)

Hydrogen is a clean and new energy carrier to generate power through the Proton exchange membrane fuel cell (PEMFC) system. Hydrogen can be effectively turned out through the catalytic gasification of organic material such as automotive shredder residues (ASR). The main objective of this manuscript is to present an analysis of the catalytic gasification of ASR for the generation of high-purity hydrogen in a lab-scale fixed-bed downdraft gasifier using 15 wt.% NiO/Al2O3 catalysts at 760–900 K. In the catalytic gasification process, reduction of Ni(II) catalyst into Ni(0) has been confirmed through XANES spectra and consequently EXAFS data shows that the central Ni atoms have Ni–O and Ni–Ni bonds with bond distances of 2.03 ± 0.05 and 2.46 ± 0.05 Å, respectively. ASR is partially oxidized and ultimately converts into hydrogen rich syngas (CO and H2) and increases of the reaction temperature are favored the generation of hydrogen with decomposition of the CO. As well, approximately 220 kg h?1 of ASR would be catalytically gasified at 760–900 K and 46.2 atm with the reactor volume 0.27 m3 to obtain approximately 3.42 × 105 kcal h?1 of thermal energy during over 87% syngas generation with the generation of 100 kW electric powers.

Kuen-Song Lin; Sujan Chowdhury; Ze-Ping Wang

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal catalytic cracking" 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.


121

Response of Surface Cracks in Tubular Members During Global Buckling and Instability  

Science Journals Connector (OSTI)

Abstract Beam-columns in compression are subject to potential buckling. If the axial load is combined with a global bending moment, member instability may occur. One situation where this can occur is for pipelines on the seabed, where thermal strains induce significant compression in the pipeline due to constrained expansion. This may lead to upheaval buckling or snaking. In this condition one should also assess how a weld defect in the buckle zone will evolve. If the crack is located on the compressive side of the cross section, the crack remains closed. If the crack is located on the side where beam bending eventually leads to tension, fracture may develop. This has not been studied sufficiently in the past, and is the topic of the present paper. Here the interesting case of initial compression, with closure of the crack, is followed by a transition to tension and opening of the crack when the transverse displacement increases in the post-buckling regime. Simple cases of tubular beam-columns with surface cracks are investigated for cracks growing in a ductile manner. The simulations are based on shell and linespring finite elements.

Bjørn Skallerud

2014-01-01T23:59:59.000Z

122

Understanding ammonia selective catalytic reduction kinetics...  

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

temperature programmed reduction (TPR), and electron paramagnetic resonance (EPR) spectroscopy. Catalytic properties are examined using NO oxidation, ammonia oxidation,...

123

Coolant Sub-Channel and Smeared-Cracking Models in BISON | Department of  

Broader source: Energy.gov (indexed) [DOE]

Coolant Sub-Channel and Smeared-Cracking Models in BISON Coolant Sub-Channel and Smeared-Cracking Models in BISON Coolant Sub-Channel and Smeared-Cracking Models in BISON January 29, 2013 - 10:45am Addthis Coolant Sub-Channel and Smeared-Cracking Models in BISON A single-pin coolant sub-channel model was implemented in BISON, the pin-scale simulation code. This enables BISON to compute the heat transfer coefficient and coolant temperature as a function of axial position along the fuel pin (rather than requiring this information to be supplied by the user). At present, the model is only applicable to pressurized water reactor coolant conditions, but modifications to include boiling water reactor (BWR) coolant conditions are in progress. A preliminary UO2 thermal and irradiation creep model has been implemented in BISON and is

124

Stiffness reduction and stress transfer in composite laminates with transverse matrix cracks  

E-Print Network [OSTI]

-staggered cracking. Laminates with staggered cracks showed a greater reduction in effective modulus at lower crack densities. The crack opening displacements at different crack densities were normalized in a way as to compare with the solution for an isolated crack...

Praveen, Grama Narasimhaprasad

2012-06-07T23:59:59.000Z

125

Catalytic Device International LLC | Open Energy Information  

Open Energy Info (EERE)

Catalytic Device International LLC Catalytic Device International LLC Jump to: navigation, search Name Catalytic Device International LLC Place Pleasanton, California Product California-based, firm focused on portable, heat-on-demand products. References Catalytic Device International LLC[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Catalytic Device International LLC is a company located in Pleasanton, California . References ↑ "Catalytic Device International LLC" Retrieved from "http://en.openei.org/w/index.php?title=Catalytic_Device_International_LLC&oldid=343285" Categories: Clean Energy Organizations Companies Organizations Stubs What links here Related changes Special pages

126

A new mineralogical approach to predict coefficient of thermal expansion of aggregate and concrete  

E-Print Network [OSTI]

the construction allows for accurate prediction of the potential thermal change on crack development and crack width and enhances the overall design process. Siliceous gravel use results in larger crack width than does the limestone and at low temperature... increment between the contacts to the flask volume, the amount of aggregate in the flask, and the thermal characteristics of the aggregate. For measurements made below the freezing point of water, a non-reactive liquid, such as toluene, which does...

Neekhra, Siddharth

2005-02-17T23:59:59.000Z

127

A NOVEL TECHNIQUE TO GENERATE SHARP CRACKS IN METALLIC/CERAMIC FUNCTIONALLY GRADED  

E-Print Network [OSTI]

materials with high fracture toughness and elevated temperature resistance. Ideally, the ceramic side of the FGM provides thermal and corrosion resistance while the metallic side gives the necessary strengthA NOVEL TECHNIQUE TO GENERATE SHARP CRACKS IN METALLIC/CERAMIC FUNCTIONALLY GRADED MATERIALS

Paulino, Glaucio H.

128

ABSTRACT. The stress-relief cracking (SRC) susceptibility of single-pass welds  

E-Print Network [OSTI]

steel, HCM2S, has been evaluated and compared to 2.25Cr-1Mo steel using Gleeble thermal simulation and pressure vessels for chemical and fossil power plants. Many components in these power plants oper- ate techniques. HCM2S was found to be more susceptible to stress-relief cracking than 2.25Cr-1Mo steel. Simulated

DuPont, John N.

129

Study on grain boundary character and strain distribution of intergranular cracking in the CGHAZ of T23 steel  

SciTech Connect (OSTI)

Intergranular reheat cracking in the coarse-grained heat-affected zone of T23 steel was produced by strain to fracture tests on a Gleeble 3500 thermal–mechanical simulator. Then the grain boundary character, as well as the strain distribution after reheat crack propagation, was studied by electron backscatter diffraction technique. The results showed that incoherent ?3 boundaries were seldom found on the prior austenite grain boundaries. Therefore, only the type of random high-angle boundaries played a crucial role in the intergranular cracking. Microstructurally cavities and small cracks were preferentially initiated from high-angle grain boundaries. Low-angle grain boundaries and high-angle ones with misorientation angles less than 15° were more resistant to the cracking. More importantly, the fraction of high-angle grain boundaries increased with the plastic strain induced by both temperature gradient and stress in the coarse-grained heat-affected zone, which contributed to the crack initiation and propagation. Furthermore, the strain distributions in the vicinity of cavities and cracks revealed the accommodation processes of plastic deformation during stress relaxation. It also reflected the strength differences between grain interior and grain boundary at different heat-treated temperatures, which had a large influence on the cracking mechanism. - Highlights: • The coincidence site lattice boundaries play little role in the reheat cracking. • Cavity and crack occur at high-angle grain boundaries rather than low-angle ones. • The strain leads low-angle grain boundaries to transform to high-angle ones. • Strain distribution differs for cavity and crack zones at different temperatures.

Jin, Y.J.; Lu, H., E-mail: shweld@sjtu.edu.cn; Yu, C.; Xu, J.J.

2013-10-15T23:59:59.000Z

130

White Etching Cracks | Argonne National Laboratory  

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

Etching Cracks Presented by Walter Holweger of Schaeffler at the Wind Turbine Tribology Seminar 2014. NREL Chicago291014Holweger26nosec...

131

Selective catalytic reduction used at Scanraff to reduce NO{sub x}, particulate emissions from FCCU  

SciTech Connect (OSTI)

This article describes various studies conducted to identify how the Scanraff Refinery in Sweden could best comply with environmental legislation for NO{sub x} and particulate emissions. Initial work identified flue gas from the catalyst regenerator of the fluidized catalytic cracking unit as the largest single source of NO{sub x} emissions. A more detailed study identified process modifications to reduce emissions, including the addition of a selective catalytic reduction (SCR) unit and a ceramic hot-gas filter. For the SCR unit, subtopics discussed include design option selection, SCR size and performance, selection of catalyst, catalyst configuration and performance, contamination, and modification of the waste heat boiler. The description of the hot-gas filtration system includes a comparison with electrostatic precipitator systems, the Schumacher filter, filtration medium, design temperature, and handling.

Brook, P.; Hagger, B.; Wood, J. [Foster Wheeler Energy Limited, Reading (United Kingdom)

1996-12-31T23:59:59.000Z

132

Overview of the DOE studies of recovery boiler floor tube cracking  

SciTech Connect (OSTI)

Cracking of the stainless steel layer of coextruded 304L/SA210 recovery boiler floor tubes has been observed in an increasing number of black liquor recovery boilers. Because failure of such tubes is a serious safety concern as well as an economic issue, this project was initiated with the objective of identifying alternate materials or process changes that would prevent tube cracking. Tensile stresses are essential for the most likely failure mechanisms, i.e., fatigue or stress corrosion cracking, therefore stresses were measured at room temperature and modeling was used to predict stresses under operating conditions. Laboratory studies have identified conditions under which composite tubes crack due to thermal fatigue and stress corrosion. Floor tube temperature measurements have defined the magnitude and frequency of temperature fluctuations experienced by such tubes, and smelt corrosion studies have measured the degradation rate when molten smelt comes in contact with tubes. Based on these observations, certain materials appear more likely to resist cracking and certain process changes should help avoid conditions that cause composite tube cracking.

Keiser, J.R.; Taljat, B.; Wang, X.L. [and others

1998-03-01T23:59:59.000Z

133

Biomaterials 24 (2003) 52095221 Crack blunting, crack bridging and resistance-curve fracture  

E-Print Network [OSTI]

Biomaterials 24 (2003) 5209­5221 Crack blunting, crack bridging and resistance-curve fracture focused on a description of the fracture toughness properties of dentin in terms of resistance-curve (R-curve) behavior, i.e., fracture resistance increasing with crack extension, particularly in light of the relevant

Ritchie, Robert

134

Effects of Current upon Electrochemical Catalytic Reforming of Anisole  

Science Journals Connector (OSTI)

The reforming of anisole (as model compound of bio-oil) was performed over the NiCuZn-Al2O3 catalyst, using a recently-developed electrochemical catalytic reforming (ECR). The influence of the current on the anisole reforming in the ECR process has been investigated. It was observed that anisole reforming was significantly enhanced by the current approached over the catalyst in the electrochemical catalytic process, which was due to the non-uniform temperature distribution in the catalytic bed and the role of the thermal electrons originating from the electrified wire. The maximum hydrogen yield of 88.7% with a carbon conversion of 98.3% was obtained through the ECR reforming of anisole at 700°C and 4 A. X-ray diffraction was employed to characterize catalyst features and their alterations in the anisole reforming. The apparent activation energy for the anisole reforming is calculated as 99.54 kJ/mol, which is higher than ethanol, acetic acid, and light fraction of bio-oil. It should owe to different physical and chemical properties and reforming mechanism for different hydrocarbons.

Jia-xing Xiong; Tao Kan; Xing-long Li; Tong-qi Ye; Quan-xin Li

2010-01-01T23:59:59.000Z

135

Chapter 10 - Regenerative catalytic oxidizer technology for VOC control  

Science Journals Connector (OSTI)

Publisher Summary The regenerative catalytic oxidizer (RCO) technology has evolved significantly as an efficient method to control volatile organic compounds. The RCO technology favors using oxide catalysts because it allows for easy compensation of lower activity by an increase in the catalyst amount or temperature. Heat transfer and accumulation properties of ceramic packing material strongly influence RCO performance. The rate of heat transfer affects the temperature gradients along the bed length that, in turn, determine the volume of material required to preheat the gas to the temperature of catalytic or thermal oxidation. During the catalyst operation, it gradually becomes less active and must be eventually replaced. The factors affecting the catalyst lifetime include high temperature, catalytic poisons, and masking agents. Compounds of halogens and sulfur are the most common catalyst poisons. Temperature control, poison tolerant catalysts, and gas-flow pretreatment are used to reduce the impact of catalyst deactivation. This chapter also presents the behavior of an RCO when the catalyst deactivates, and proposes strategies ensuring the required performance during the entire catalyst lifetime.

V.O. Strots; G.A. Bunimovich; C.R. Roach; Yu.Sh. Matros

2000-01-01T23:59:59.000Z

136

Bifunctional Catalysts for the Selective Catalytic Reduction...  

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

for the Selective Catalytic Reduction of NO by Hydrocarbons Development of Optimal Catalyst Designs and Operating Strategies for Lean NOx Reduction in Coupled LNT-SCR Systems...

137

Synthesis, Characterization, and Catalytic Function of Novel...  

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

Function of Novel Highly Dispersed Tungsten Oxide Catalysts on Mesoporous Silica . Synthesis, Characterization, and Catalytic Function of Novel Highly Dispersed Tungsten Oxide...

138

Characterization of Fatigue Cracking and Healing of Asphalt Mixtures  

E-Print Network [OSTI]

Fatigue cracking is one of the most common distresses of asphalt pavements, whereas healing is a counter process to cracking which alleviates cracking damage and extends fatigue life of asphalt pavements. Most of existing methods to characterize...

Luo, Xue

2012-07-16T23:59:59.000Z

139

Effect of Desiccation Cracks on Earth Embankments  

E-Print Network [OSTI]

............................................................................. 4 1.4 Methodology ........................................................................................ 6 1.5 Summary .............................................................................................. 8 1.6 Layout... geometry recorded in literature ..... 17 2.5 Desiccation crack behavior during drying-wetting cycles ................... 29 2.6 Flow through a single crack ................................................................. 30 2.7 Flow through a...

Khandelwal, Siddharth

2012-07-11T23:59:59.000Z

140

3:2:1 Crack Spread  

Gasoline and Diesel Fuel Update (EIA)

:2:1 Crack Spread :2:1 Crack Spread Figure 1 Source: U.S. Energy Information Administration, based on Thomson Reuters. A crack spread measures the difference between the purchase price of crude oil and the selling price of finished products, such as gasoline and distillate fuel, that a refinery produces from the crude oil. Crack spreads are an indicator of the short-term profit margin of oil refineries because they compare the cost of the crude oil inputs to the wholesale, or spot, prices of the outputs (although they do not include other variable costs or any fixed costs). The 3:2:1 crack spread approximates the product yield at a typical U.S. refinery: for every three barrels of crude oil the refinery processes, it makes two barrels of gasoline and one barrel of distillate

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


141

High-Resolution Crack Imaging Reveals Degradation Processes in...  

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

Crack Imaging Reveals Degradation Processes in Nuclear Reactor Structural Materials. High-Resolution Crack Imaging Reveals Degradation Processes in Nuclear Reactor Structural...

142

Catalytic steam reforming of hydrocarbons  

SciTech Connect (OSTI)

The hot effluent from the catalytic steam reforming of a major portion of a fluid hydrocarbon feed stream in the reformer tubes of a primary reformer, or said effluent after secondary reforming thereof, is mixed with the hot effluent from the catalytic steam reforming of the remaining portion of the feed discharged from the reformer tubes of a primary reformer-exchanger. The combined gas steam is passed on the shell side of the reformer-exchanger countercurrently to the passage of feed in the reformer tubes thereof, thus supplying the heat for the reforming of the portion of the feed passed through the reformer tubes of the reformerexchanger. At least about 2/3 of the hydrocarbon feed stream is passed to the reformer tubes of said primary reformer, heated by radiant heat transfer and/or by contact with combustion gases, at a steam/hydrocarbon mole ratio of about 2-4/1. The remainder of said feed stream is passed to the reformer tubes of said reformer -exchanger at a steam/hydrocarbon mole ratio of about 3-6/1. The reformer shell of the reformer-exchanger is internally insulated by a refractory lining or by use of a double shell with passage of water or a portion of the feed material between the inner and outer shells. There is no significant difference between the pressure inside and outside of the reformer tubes of said primary reformer-exchanger.

Fuderer, A.

1982-06-29T23:59:59.000Z

143

Utilization of char from biomass gasification in catalytic applications  

E-Print Network [OSTI]

Utilization of char from biomass gasification in catalytic applications Naomi Klinghoffer Submitted Utilization of char from biomass gasification in catalytic applications Naomi Klinghoffer Utilization takes place during catalytic decomposition. This thesis focuses on the utilization of char as a catalyst

144

Early stages in the development of stress corrosion cracks  

SciTech Connect (OSTI)

Processes in growth of short cracks and stage I of long stress corrosion cracks were identified and evaluated. There is evidence that electrochemical effects can cause short stress corrosion cracks to grow at rates faster or slower than long cracks. Short cracks can grow at faster rates than long cracks for a salt film dissolution growth mechanism or from reduced oxygen inhibition of hydrolytic acidification. An increasing crack growth rate with increasing crack length could result from a process of increasing crack tip concentration of a critical anion, such as Cl{sup {minus}}, with increasing crack length in a system where the crack velocity is dependent on the Cl{sup {minus}} or some other anion concentration. An increasing potential drop between crack tip and mouth would result in an increased anion concentration at the crack tip and hence an increasing crack velocity. Stage I behavior of long cracks is another early development stage in the life of a stress corrosion crack which is poorly understood. This stage can be described by da/dt = AK{sup m} where da/dt is crack velocity, A is a constant, K is stress intensity and m ranges from 2 to 24 for a variety of materials and environments. Only the salt film dissolution model was found to quantitatively describe this stage; however, the model was only tested on one material and its general applicability is unknown.

Jones, R.H.; Simonen, E.P.

1993-12-01T23:59:59.000Z

145

Microstructural and Microchemical Characterization of Dual Step Aged Alloy X-750 and its Relationship to Environmentally Assisted Cracking  

SciTech Connect (OSTI)

When exposed to deaerated high purity water, Alloy X-750 is susceptible to both high temperature (> 249 C) intergranular stress corrosion cracking (IGSCC) and intergranular low temperature (< 149 C) fracture (LTF). However, the microstructural and microchemical factors that govern environmentally assisted cracking (EAC) susceptibility are poorly understood. The present study seeks to characterize the grain boundary microstructure and microchemistry in order to gain a better mechanistic understanding of stress corrosion crack initiation, crack growth rate, and low temperature fracture. Light microscopy, scanning electron microscopy, transmission electron microscopy, orientation imaging microscopy, scanning Auger microscopy, and thermal desorption spectroscopy were performed on selected heats of Alloy X-750 AH. These data were correlated to EAC tests performed in 338 C deaerated water. Results show that grain boundary MC-type [(Ti,Nb)C] carbides and increased levels of grain boundary phosphorus correlate with an increase in LTF susceptibility but have little effect on the number of initiation sites or the SCC crack growth rate. Thermal desorption data show that multiple hydrogen trapping states exist in Alloy X-750 condition AH. Moreover, it appears that exposure to high temperature (> 249 C), hydrogen deaerated water increases the hydrogen concentration in strong hydrogen trap states and degrades the resistance of the material to low temperature fracture. These findings are consistent with a hydrogen embrittlement based mechanism of LTF where intergranular fracture occurs ahead of a crack tip and is exacerbated by phosphorus segregation to grain boundaries and grain boundary hydrogen trap states.

G.A. Young; N. Lewis; M. Hanson; W. Matuszyk; B. Wiersma; S. Gonzalez

2001-05-08T23:59:59.000Z

146

Passive Catalytic Approach to Low Temperature NOx Emission Abatement...  

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

Catalytic Approach to Low Temperature NOx Emission Abatement Passive Catalytic Approach to Low Temperature NOx Emission Abatement Numerically evaluated and optimized proposed...

147

Measurement of diesel solid nanoparticle emissions using a catalytic...  

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

diesel solid nanoparticle emissions using a catalytic stripper for comparison with Europe's PMP protocol Measurement of diesel solid nanoparticle emissions using a catalytic...

148

Fuel-Flexible, Low-Emissions Catalytic Combustor for Opportunity...  

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

Flexible, Low-Emissions Catalytic Combustor for Opportunity Fuels Fuel-Flexible, Low-Emissions Catalytic Combustor for Opportunity Fuels This fact sheet provides an overview of the...

149

Catalytic Hydrothermal Gasification of Biomass  

SciTech Connect (OSTI)

A recent development in biomass gasification is the use of a pressurized water processing environment in order that drying of the biomass can be avoided. This paper reviews the research undertaken developing this new option for biomass gasification. This review does not cover wet oxidation or near-atmospheric-pressure steam-gasification of biomass. Laboratory research on hydrothermal gasification of biomass focusing on the use of catalysts is reviewed here, and a companion review focuses on non-catalytic processing. Research includes liquid-phase, sub-critical processing as well as super-critical water processing. The use of heterogeneous catalysts in such a system allows effective operation at lower temperatures, and the issues around the use of catalysts are presented. This review attempts to show the potential of this new processing concept by comparing the various options under development and the results of the research.

Elliott, Douglas C.

2008-05-06T23:59:59.000Z

150

Catalytic converter with thermoelectric generator  

SciTech Connect (OSTI)

The unique design of an electrically heated catalyst (EHC) and the inclusion of an ECO valve in the exhaust of an internal combustion engine will meet the strict new emission requirements, especially at vehicle cold start, adopted by several states in this country as well as in Europe and Japan. The catalytic converter (CC) has been a most useful tool in pollution abatement for the automobile. But the emission requirements are becoming more stringent and, along with other improvements, the CC must be improved to meet these new standards. Coupled with the ECO valve, the EHC can meet these new emission limits. In an internal combustion engine vehicle (ICEV), approximately 80% of the energy consumed leaves the vehicle as waste heat: out the tail pipe, through the radiator, or convected/radiated off the engine. Included with the waste heat out the tail pipe are the products of combustion which must meet strict emission requirements. The design of a new CC is presented here. This is an automobile CC that has the capability of producing electrical power and reducing the quantity of emissions at vehicle cold start, the Thermoelectric Catalytic Power Generator. The CC utilizes the energy of the exothermic reactions that take place in the catalysis substrate to produce electrical energy with a thermoelectric generator. On vehicle cold start, the thermoelectric generator is used as a heat pump to heat the catalyst substrate to reduce the time to catalyst light-off. Thus an electrically heated catalyst (EHC) will be used to augment the abatement of tail pipe emissions. Included with the EHC in the exhaust stream of the automobile is the ECO valve. This valve restricts the flow of pollutants out the tail pipe of the vehicle for a specified amount of time until the EHC comes up to operating temperature. Then the ECO valve opens and allows the full exhaust, now treated by the EHC, to leave the vehicle.

Parise, R.J.

1998-07-01T23:59:59.000Z

151

Stress corrosion cracking of power boiler drums  

Science Journals Connector (OSTI)

This paper deals with the study, analysis and technical diagnosis fundamentals concerning damage induced by stress corrosion cracking. The main repair and safe operation methods for power boiler drums are described; this work being based on plant experience.

Alecsandru Pavel; Alexandru Pelle; Alexandru Epure; Cornel Radulescu; Petric? Baciu; Alexandru Bogdan; Mihai Stefanescu

1991-01-01T23:59:59.000Z

152

Methodology for extracting local constants from petroleum cracking flows  

DOE Patents [OSTI]

A methodology provides for the extraction of local chemical kinetic model constants for use in a reacting flow computational fluid dynamics (CFD) computer code with chemical kinetic computations to optimize the operating conditions or design of the system, including retrofit design improvements to existing systems. The coupled CFD and kinetic computer code are used in combination with data obtained from a matrix of experimental tests to extract the kinetic constants. Local fluid dynamic effects are implicitly included in the extracted local kinetic constants for each particular application system to which the methodology is applied. The extracted local kinetic model constants work well over a fairly broad range of operating conditions for specific and complex reaction sets in specific and complex reactor systems. While disclosed in terms of use in a Fluid Catalytic Cracking (FCC) riser, the inventive methodology has application in virtually any reaction set to extract constants for any particular application and reaction set formulation. The methodology includes the step of: (1) selecting the test data sets for various conditions; (2) establishing the general trend of the parametric effect on the measured product yields; (3) calculating product yields for the selected test conditions using coupled computational fluid dynamics and chemical kinetics; (4) adjusting the local kinetic constants to match calculated product yields with experimental data; and (5) validating the determined set of local kinetic constants by comparing the calculated results with experimental data from additional test runs at different operating conditions.

Chang, Shen-Lin (Woodridge, IL); Lottes, Steven A. (Naperville, IL); Zhou, Chenn Q. (Munster, IN)

2000-01-01T23:59:59.000Z

153

Gasoline conversion: reactivity towards cracking with equilibrated FCC and ZSM-5 catalysts  

Science Journals Connector (OSTI)

Cracking of a straight-run FCC gasoline using either a steamed ZSM-5 catalyst or a base, FCC equilibrium, catalyst shows that the only significantly reactive components in the gasoline fraction are normal and branched olefins with a carbon number of seven and higher. Overall, the reactivity of gasoline is one to two orders of magnitude smaller than that of a normal FCC feedstock. The ZSM-5 catalyst produces light olefins (LPG-range and some ethene) through cracking of the gasoline-range olefins. The base catalyst produces these light olefins in lower amounts than ZSM-5 does. Further, the base catalyst produces small amounts of paraffins and products that are heavier than the gasoline feedstock. The overall reason for the differences between the two catalysts is a shape-selective mechanism; in the small pores of ZSM-5 only monomolecular cracking reactions take place, while in the larger pores of the FCC base catalyst also a bimolecular reaction mechanism is operative. As a result of the absence of bimolecular reactions, with ZSM-5, the average size of the products and the amount of hydrogen transfer products is smaller than with the base catalyst. On the other hand, because of the relatively small pore size of ZSM-5, the interaction between the catalytic surface of ZSM-5 and the reactants is larger resulting in a higher conversion of linear olefins and a higher production of ethene than with the base catalyst.

M.A. den Hollander; M. Wissink; M. Makkee; J.A. Moulijn

2002-01-01T23:59:59.000Z

154

Parallel interacting edge cracks under pure bending  

E-Print Network [OSTI]

. Once the applicability of the Williams' equations, have been proved or disproved, the power of the singularity represented by the first term of equation 1. 1 and the polynomial expansion can be truncated in order to extract information... of Williams' approach for the case of cracked bodies under pure bending is demonstrated. Four point bending load is applied on specimens with either a vertical or a slant crack giving Mode I or Mixed Mode I ? II respectively. The existence...

Moran, Ivan

1991-01-01T23:59:59.000Z

155

Studies on fruit cracking of tomatoes  

E-Print Network [OSTI]

STUDIES ON FRUIT CRACKING OF TOMATOES A Thesis Sam Don Cotner Submitted to the Graduate College of' ths Texas A&M University in partial fulfillment of the requirements i' or the degree of MASTER OF SCIENCE January~ 1966 Major Subject...: Horticulture STUDlES ON FRUIT CRACKING OF TOMATOES A Thesis Sam Dcn Cotnsr Approved as to style and content by; (Chairman of tes Member (Head o Department) mbsr) January 1966 TABLE OF CONTENTS Chapter I. INTRODUCTION . II. REVIEW OF LITERATURE Page...

Cotner, Sam Don

1966-01-01T23:59:59.000Z

156

Lattice Boltzmann simulation of catalytic reactions  

Science Journals Connector (OSTI)

A lattice Boltzmann model is developed to simulate finite-rate catalytic surface chemistry. Diffusive wall boundary conditions are established to account for catalytic reactions in multicomponent mixtures. Implementation of wall boundary conditions with chemical reactions is based on a general second-order accurate interpolation scheme. Results of lattice Boltzmann simulations for a four-component mixture with a global catalytic methane oxidation reaction in a straight channel are in excellent agreement with a finite volume Navier-Stokes solver in terms of both the flow field and species concentrations.

S. Arcidiacono; J. Mantzaras; I. V. Karlin

2008-10-28T23:59:59.000Z

157

Crack-Size Effects on Cyclic and Monotonic Crack Growth in Polycrystalline Alumina: Quantification of the Role of Grain Bridging  

E-Print Network [OSTI]

-prediction methodologies, it is necessary in many materials that the subcritical crack-growth and toughness propertiesCrack-Size Effects on Cyclic and Monotonic Crack Growth in Polycrystalline Alumina: Quantification propagation has been quantitatively examined in a 99.5% pure alumina. Fatigue-crack growth properties for both

Ritchie, Robert

158

High pressure test results of a catalytically assisted ceramic combustor for a gas turbine  

SciTech Connect (OSTI)

A catalytically assisted ceramic combustor for a gas turbine was designed to achieve low NOx emission under 5 ppm at a combustor outlet temperature over 1300 C. This combustor is composed of a burner system and a ceramic liner behind the burner system. The burner system consist of 6 catalytic combustor segments and 6 premixing nozzles, which are arranged in parallel and alternately. The ceramic liner is made up of the layer of outer metal wall, ceramic fiber, and inner ceramic tiles. Fuel flow rates for the catalysts and the premixing nozzles are controlled independently. Catalytic combustion temperature is controlled under 1000 C, premixed gas is injected from the premixing nozzles to the catalytic combustion gas and lean premixed combustion over 1300 C is carried out in the ceramic liner. This system was designed to avoid catalytic deactivation at high temperature and thermal and mechanical shock fracture of the honeycomb monolith of catalyst. A combustor for a 10 MW class, multican type gas turbine was tested under high pressure conditions using LNG fuel. Measurements of emission, temperature, etc. were made to evaluate combustor performance under various combustion temperatures and pressures. This paper presents the design features and the test results of this combustor.

Ozawa, Y.; Tochihara, Y.; Mori, N.; Yuri, I. [Central Research Inst. of Electric Power Industry, Yokosuka, Kanagawa (Japan); Kanazawa, T.; Sagimori, K. [Kansai Electric Power Co., Inc., Amagasaki, Hyogo (Japan)

1999-07-01T23:59:59.000Z

159

Glycoside hydrolases: Catalytic base/nucleophile diversity  

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

Glycoside Glycoside Hydrolases: Catalytic Base/Nucleophile Diversity Thu V. Vuong, David B. Wilson Department of Molecular Biology and Genetics, Cornell University, 458 Biotechnology Building, Ithaca, New York 14850; telephone: 607-255-5706; fax: 607-255-2428; e-mail: dbw3@cornell.edu Received 1 April 2010; revision received 27 May 2010; accepted 2 June 2010 Published online 15 June 2010 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/bit.22838 ABSTRACT: Recent studies have shown that a number of glycoside hydrolase families do not follow the classical catalytic mechanisms, as they lack a typical catalytic base/ nucleophile. A variety of mechanisms are used to replace this function, including substrate-assisted catalysis, a network of several residues, and the use of non-carboxylate residues or exogenous nucleophiles. Removal of the catalytic base/ nucleophile

160

Preparation, Characterization, and Catalytic Properties of Tungsten...  

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

Abstract: The structure and catalytic activity of tungsten oxide clusters formed via sublimation of monodispersed cyclic (WO3)3 onto FeO(111)Pt(111) surface has been studied...

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


161

Bifunctional Catalysts for the Selective Catalytic Reduction...  

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

Reduction of NO by Hydrocarbons Selectlive Catalytic Reducution of NOx wilth Diesel-Based Fuels as Reductants Engine and Reactor Evaluations of HC-SCR for Diesel NOx Reduction...

162

Microsecond Catalytic Partial Oxidation of Alkanes  

Science Journals Connector (OSTI)

...HICKMAN A. D. , PRODUCTION OF SYNGAS BY DIRECT CATALYTIC-OXIDATION OF METHANE...PFEFFERLE D. L. , CATALYSIS IN COMBUSTION , CATALYSIS...a-alu-mina monoliths coated with Rh (for syngas) (1, 2) or with Pt (for olefins...

Duane A. Goetsch; Lanny D. Schmidt

1996-03-15T23:59:59.000Z

163

Vacuum-insulated catalytic converter  

DOE Patents [OSTI]

A catalytic converter has an inner canister that contains catalyst-coated substrates and an outer canister that encloses an annular, variable vacuum insulation chamber surrounding the inner canister. An annular tank containing phase-change material for heat storage and release is positioned in the variable vacuum insulation chamber a distance spaced part from the inner canister. A reversible hydrogen getter in the variable vacuum insulation chamber, preferably on a surface of the heat storage tank, releases hydrogen into the variable vacuum insulation chamber to conduct heat when the phase-change material is hot and absorbs the hydrogen to limit heat transfer to radiation when the phase-change material is cool. A porous zeolite trap in the inner canister absorbs and retains hydrocarbons from the exhaust gases when the catalyst-coated substrates and zeolite trap are cold and releases the hydrocarbons for reaction on the catalyst-coated substrate when the zeolite trap and catalyst-coated substrate get hot.

Benson, David K. (Golden, CO)

2001-01-01T23:59:59.000Z

164

Test results of a catalytically assisted combustor for a gas turbine  

Science Journals Connector (OSTI)

A catalytically assisted ceramic combustor for a gas turbine was designed and tested to achieve low \\{NOx\\} emissions. This combustor is composed of a burner and a ceramic liner. The burner consists of an annular preburner, six catalytic combustor segments and six premixing nozzles, which are arranged in parallel and alternately. In this combustor system, catalytic combustion temperature is controlled under 1000 °C, premixed gas is injected from the premixing nozzles to the catalytic combustion gas and lean premixed combustion over 1300 °C is carried out in the ceramic liner. This system was designed to avoid catalyst deactivation at high temperature and thermal shock fracture of the ceramic honeycomb monolith of the catalyst. A 1 MW class combustor was tested using LNG fuel. Firstly, \\{NOx\\} emissions from the preburner were investigated under various pressure conditions. Secondly, two sets of honeycomb cell density catalysts and one set of thermally pretreated catalysts ware applied to the combustor, and combustion tests were carried out under various pressure conditions. As a result, it was found that the main source of \\{NOx\\} was the preburner, and total \\{NOx\\} emissions from the combustor were approximately 4 ppm (at 16% O2) at an adiabatic combustion temperature of 1350 °C and combustor inlet pressure of 1.33 MPa.

Yasushi Ozawa; Yoshihisa Tochihara; Noriyuki Mori; Isao Yuri; Junichi Sato; Koji Kagawa

2003-01-01T23:59:59.000Z

165

Effects of thermal pretreatment (removal of steric hindrance) on subsequent nuclear hydrogenation of heavy alkylaromatics  

SciTech Connect (OSTI)

The changes in structures by thermal pretreatment of heavy alkylaromatics, which are very difficult to nuclear hydrogenate, and the effects of the pretreatment on subsequent nuclear hydrogenation were investigated in comparison with catalytic pretreatment of the same feedstock. The following results were obtained: (1) the structures of the thermally pretreated products are quite different from those of the catalytically pretreated ones; (2) subsequent nuclear hydrogenation of the thermally pretreated products becomes much easier because the steric hindrance is removed; (3) in the case where the same feedstock was catalytically pretreated, the products were difficult to nuclear hydrogenate. These results suggest various applications, including heavy oil hydrotreating.

Kubo, Junichi [Nippon Oil Co., Ltd., Yokohama (Japan). Central Technical Research Lab.] [Nippon Oil Co., Ltd., Yokohama (Japan). Central Technical Research Lab.

1996-01-01T23:59:59.000Z

166

The analysis of cracks in high-pressure piping and their effects on strength and lifetime of construction components at the Ignalina nuclear plant  

SciTech Connect (OSTI)

A number of cracks and damages of other sorts have been identified in the high-pressure parts at the Ignalina Nuclear Plant. They are caused by inadequate production- and repair technologies, as well as by thermal, chemical and mechanical processes of their performance. Several techniques are available as predictions of cracks and other defects of pressurized vessels. The choice of an experimental technique should be based on the level of its agreement with the actual processes.

Aleev, A.; Petkevicius, K.; Senkus, V. [and others

1997-04-01T23:59:59.000Z

167

Thermal spray coatings on Yankee dryers  

SciTech Connect (OSTI)

Several failure investigations and recent research on thermal spray coatings on Yankee dryer surfaces show at least three modes of environmentally induced degradation. Corrosion may occur with the ingress of certain chemicals into coating pores. Erosion or corrosion is manifested by streaks at local sites of high doctor blade loading. Erosion and cracking occur due to coating parameters, thermal stress, and differential expansion. While most of the results described in this paper are from investigations of molybdenum, stainless steel coatings also are discussed.

Bowers, D.F. (Packer Engineering, Inc., Naperville, IL (United States))

1994-08-01T23:59:59.000Z

168

Fracture mechanics and subcritical crack growth approach to model time-dependent failure in brittle rock.  

E-Print Network [OSTI]

??Subcritical crack growth (SCG) takes place when a crack is stressed below its short-term strength. This slow fracturing process may lead to an accelerating crack… (more)

Rinne, Mikael

2008-01-01T23:59:59.000Z

169

E-Print Network 3.0 - axially cracked pressure Sample Search...  

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

Collection: Engineering 2 MATERIAL POINT METHOD CALCULATIONS WITH EXPLICIT CRACKS, FRACTURE PARAMETERS, AND CRACK Summary: under axial impact with a crack in the central disk....

170

E-Print Network 3.0 - anomolous fatigue crack Sample Search Results  

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

Science ; Engineering 6 Cracking Resistance of Asphalt Rubber Mix Versus Summary: vs. Fracture Mechanics Conventional Fatigue Testing Crack initiation Fracture Mechanics Crack......

171

Interfacial and near interfacial crack growth phenomena in metal bonded alumina  

E-Print Network [OSTI]

studies looking at subcritical crack growth at interfaces,An understanding of subcritical crack growth is important,the amount of subcritical crack growth data that could be

Kruzic, Jamie Joseph

2002-01-01T23:59:59.000Z

172

Plasma catalytic reforming of methane  

Science Journals Connector (OSTI)

Thermal plasma technology can be efficiently used in the production of hydrogen and hydrogen-rich gases from methane and a variety of fuels. This article describes progress in plasma reforming experiments and calculations of high temperature conversion of methane using heterogeneous processes. The thermal plasma is a highly energetic state of matter that is characterized by extremely high temperatures (several thousand degrees Celsius), and a high degree of dissociation and a substantial degree of ionization. The high temperatures accelerate the reactions involved in the reforming process. Hydrogen-rich gas (40% H2, 17% CO2 and 33% N2, for partial oxidation/water shifting) can be efficiently made in compact plasma reformers. Experiments have been carried out in a small device (2–3 kW) and without the use of efficient heat regeneration. For partial oxidation/water shifting, it was determined that the specific energy consumption in the plasma reforming processes is 16 MJ/kg H2 with high conversion efficiencies. Larger plasmatrons, better reactor thermal insulation, efficient heat regeneration and improved plasma catalysis could also play a major role in specific energy consumption reduction and increasing the methane conversion. A system has been demonstrated for hydrogen production with low CO content (?1.5%) with power densities of ?30 kW (H2 HHV)/l of reactor, or ?10 m3/h H2 per liter of reactor. Power density should further increase with increased power and improved design.

L Bromberg; D.R Cohn; A Rabinovich; N Alexeev

1999-01-01T23:59:59.000Z

173

Surface Modification of Nanoclays by Catalytically Active Transition Pranav Nawani, Mikhail Y. Gelfer, Benjamin S. Hsiao,*, Anatoly Frenkel,  

E-Print Network [OSTI]

Surface Modification of Nanoclays by Catalytically Active Transition Metal Ions Pranav Nawani, New York 11973-5000 ReceiVed March 29, 2007. In Final Form: May 20, 2007 A unique class of nanoclays). The composition, structure, morphology and thermal properties of TMI-modified nanoclays were investigated

Frenkel, Anatoly

174

Catalytic pyrolysis of straight-run gasoline on a promoted vanadium catalyst  

SciTech Connect (OSTI)

Over the years the catalytic pyrolysis has been studied of various hydrocarbon materials - from gaseous (ethane, propane and n-butane) to heavy petroleum fractions with an end boiling point higher than 500/sup 0/C. The process indices for all the raw materials studied were significantly better than those from thermal pyrolysis. Improvement of operational properties for the vanadium catalyst for pyrolysis involved the selecting a better acceptor and the use of promotor additives which inhibit coke formation.

Chernykh, S.P.; Adel'son, S.V.; Rudyk, E.M.; Zhagfarov, F.G.; Motorina, I.A.; Nikonov, V.I.; Mukhina, T.N.; Barabanov, N.L.; Pyatiletov, V.I.

1983-04-01T23:59:59.000Z

175

Crack detection using resonant ultrasound spectroscopy  

DOE Patents [OSTI]

Method and apparatus are provided for detecting crack-like flaws in components. A plurality of exciting frequencies are generated and applied to a component in a dry condition to obtain a first ultrasonic spectrum of the component. The component is then wet with a selected liquid to penetrate any crack-like flaws in the component. The plurality of exciting frequencies are again applied to the component and a second ultrasonic spectrum of the component is obtained. The wet and dry ultrasonic spectra are then analyzed to determine the second harmonic components in each of the ultrasonic resonance spectra and the second harmonic components are compared to ascertain the presence of crack-like flaws in the component. 5 figs.

Migliori, A.; Bell, T.M.; Rhodes, G.W.

1994-10-04T23:59:59.000Z

176

Plasma catalytic reforming of methane  

SciTech Connect (OSTI)

Thermal plasma technology can be efficiently used in the production of hydrogen and hydrogen-rich gases from methane and a variety of fuels. This paper describes progress in plasma reforming experiments and calculations of high temperature conversion of methane using heterogeneous processes. The thermal plasma is a highly energetic state of matter that is characterized by extremely high temperatures (several thousand degrees Celsius) and high degree of dissociation and substantial degree of ionization. The high temperatures accelerate the reactions involved in the reforming process. Hydrogen-rich gas (50% H{sub 2}, 17% CO and 33% N{sub 2}, for partial oxidation/water shifting) can be efficiently made in compact plasma reformers. Experiments have been carried out in a small device (2--3 kW) and without the use of efficient heat regeneration. For partial oxidation/water shifting, it was determined that the specific energy consumption in the plasma reforming processes is 16 MJ/kg H{sub 2} with high conversion efficiencies. Larger plasmatrons, better reactor thermal insulation, efficient heat regeneration and improved plasma catalysis could also play a major role in specific energy consumption reduction and increasing the methane conversion. A system has been demonstrated for hydrogen production with low CO content ({approximately} 1.5%) with power densities of {approximately} 30 kW (H{sub 2} HHV)/liter of reactor, or {approximately} 10 m{sup 3}/hr H{sub 2} per liter of reactor. Power density should further increase with increased power and improved design.

Bromberg, L.; Cohn, D.R.; Rabinovich, A. [Massachusetts Inst. of Technology, Cambridge, MA (United States). Plasma Science and Fusion Center; Alexeev, N. [Russian Academy of Sciences, Moscow (Russian Federation). Baikov Inst. of Metallurgy

1998-08-01T23:59:59.000Z

177

Catalytic Combustor for Fuel-Flexible Turbine  

SciTech Connect (OSTI)

Under the sponsorship of the U.S. Department of Energy's National Energy Technology Laboratory, Siemens Westinghouse is conducting a three-year program to develop an ultra low NOx, fuel flexible catalytic combustor for gas turbine application in IGCC. The program is defined in three phases: Phase 1-Implementation Plan, Phase 2-Validation Testing and Phase 3-Field Testing. The Phase 1 program has been completed. Phase II was initiated in October 2004. In IGCC power plants, the gas turbine must be capable of operating on syngas as a primary fuel and an available back-up fuel such as natural gas. In this program the Rich Catalytic Lean (RCL{trademark}) technology is being developed as an ultra low NOx combustor. In this concept, ultra low NOx is achieved by stabilizing a lean premix combustion process by using a catalytic reactor to react part of the fuel, increasing the fuel/air mixture temperature. In Phase 1, the feasibility of the catalytic concept for syngas application has been evaluated and the key technology issues identified. In Phase II the catalytic concept will be demonstrated through subscale testing. Phase III will consist of full-scale combustor basket testing on natural gas and syngas.

W. R. Laster; E. Anoshkina; P. Szedlacsek

2006-03-31T23:59:59.000Z

178

Catalytic Combustor for Fuel-Flexible Turbine  

SciTech Connect (OSTI)

Under the sponsorship of the U. S. Department of Energy's National Energy Technology Laboratory, Siemens Westinghouse has conducted a three-year program to develop an ultra low NOx, fuel flexible catalytic combustor for gas turbine application in IGCC. The program is defined in three phases: Phase 1 - Implementation Plan, Phase 2 - Validation Testing and Phase 3 - Field Testing. Both Phase 1 and Phase 2 of the program have been completed. In IGCC power plants, the gas turbine must be capable of operating on syngas as a primary fuel and an available back-up fuel such as natural gas. In this program the Rich Catalytic Lean (RCLTM) technology is being developed as an ultra low NOx combustor. In this concept, ultra low NOx is achieved by stabilizing a lean premix combustion process by using a catalytic reactor to oxidize a portion of the fuel, increasing the temperature of fuel/air mixture prior to the main combustion zone. In Phase 1, the feasibility of the catalytic concept for syngas application has been evaluated and the key technology issues identified. In Phase II the technology necessary for the application of the catalytic concept to IGCC fuels was developed through detailed design and subscale testing. Phase III (currently not funded) will consist of full-scale combustor basket testing on natural gas and syngas.

W. R. Laster; E. Anoshkina

2008-01-31T23:59:59.000Z

179

Catalytic Combustor for Fuel-Flexible Turbine  

SciTech Connect (OSTI)

Under the sponsorship of the U. S. Department of Energy’s National Energy Technology Laboratory, Siemens Westinghouse has conducted a three-year program to develop an ultra low NOx, fuel flexible catalytic combustor for gas turbine application in IGCC. The program is defined in three phases: Phase 1- Implementation Plan, Phase 2- Validation Testing and Phase 3 – Field Testing. Both Phase 1 and Phase 2 of the program have been completed. In IGCC power plants, the gas turbine must be capable of operating on syngas as a primary fuel and an available back-up fuel such as natural gas. In this program the Rich Catalytic Lean (RCLTM) technology is being developed as an ultra low NOx combustor. In this concept, ultra low NOx is achieved by stabilizing a lean premix combustion process by using a catalytic reactor to oxidize a portion of the fuel, increasing the temperature of fuel/air mixture prior to the main combustion zone. In Phase 1, the feasibility of the catalytic concept for syngas application has been evaluated and the key technology issues identified. In Phase II the technology necessary for the application of the catalytic concept to IGCC fuels was developed through detailed design and subscale testing. Phase III (currently not funded) will consist of full-scale combustor basket testing on natural gas and syngas.

Laster, W. R.; Anoshkina, E.

2008-01-31T23:59:59.000Z

180

Total Number of Operable Refineries  

U.S. Energy Information Administration (EIA) Indexed Site

Data Series: Total Number of Operable Refineries Number of Operating Refineries Number of Idle Refineries Atmospheric Crude Oil Distillation Operable Capacity (B/CD) Atmospheric Crude Oil Distillation Operating Capacity (B/CD) Atmospheric Crude Oil Distillation Idle Capacity (B/CD) Atmospheric Crude Oil Distillation Operable Capacity (B/SD) Atmospheric Crude Oil Distillation Operating Capacity (B/SD) Atmospheric Crude Oil Distillation Idle Capacity (B/SD) Vacuum Distillation Downstream Charge Capacity (B/SD) Thermal Cracking Downstream Charge Capacity (B/SD) Thermal Cracking Total Coking Downstream Charge Capacity (B/SD) Thermal Cracking Delayed Coking Downstream Charge Capacity (B/SD Thermal Cracking Fluid Coking Downstream Charge Capacity (B/SD) Thermal Cracking Visbreaking Downstream Charge Capacity (B/SD) Thermal Cracking Other/Gas Oil Charge Capacity (B/SD) Catalytic Cracking Fresh Feed Charge Capacity (B/SD) Catalytic Cracking Recycle Charge Capacity (B/SD) Catalytic Hydro-Cracking Charge Capacity (B/SD) Catalytic Hydro-Cracking Distillate Charge Capacity (B/SD) Catalytic Hydro-Cracking Gas Oil Charge Capacity (B/SD) Catalytic Hydro-Cracking Residual Charge Capacity (B/SD) Catalytic Reforming Charge Capacity (B/SD) Catalytic Reforming Low Pressure Charge Capacity (B/SD) Catalytic Reforming High Pressure Charge Capacity (B/SD) Catalytic Hydrotreating/Desulfurization Charge Capacity (B/SD) Catalytic Hydrotreating Naphtha/Reformer Feed Charge Cap (B/SD) Catalytic Hydrotreating Gasoline Charge Capacity (B/SD) Catalytic Hydrotreating Heavy Gas Oil Charge Capacity (B/SD) Catalytic Hydrotreating Distillate Charge Capacity (B/SD) Catalytic Hydrotreating Kerosene/Jet Fuel Charge Capacity (B/SD) Catalytic Hydrotreating Diesel Fuel Charge Capacity (B/SD) Catalytic Hydrotreating Other Distillate Charge Capacity (B/SD) Catalytic Hydrotreating Residual/Other Charge Capacity (B/SD) Catalytic Hydrotreating Residual Charge Capacity (B/SD) Catalytic Hydrotreating Other Oils Charge Capacity (B/SD) Fuels Solvent Deasphalting Charge Capacity (B/SD) Catalytic Reforming Downstream Charge Capacity (B/CD) Total Coking Downstream Charge Capacity (B/CD) Catalytic Cracking Fresh Feed Downstream Charge Capacity (B/CD) Catalytic Hydro-Cracking Downstream Charge Capacity (B/CD) Period:

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


181

Atmospheric Crude Oil Distillation Operable Capacity  

Gasoline and Diesel Fuel Update (EIA)

(Barrels per Calendar Day) (Barrels per Calendar Day) Data Series: Total Number of Operable Refineries Number of Operating Refineries Number of Idle Refineries Atmospheric Crude Oil Distillation Operable Capacity (B/CD) Atmospheric Crude Oil Distillation Operating Capacity (B/CD) Atmospheric Crude Oil Distillation Idle Capacity (B/CD) Atmospheric Crude Oil Distillation Operable Capacity (B/SD) Atmospheric Crude Oil Distillation Operating Capacity (B/SD) Atmospheric Crude Oil Distillation Idle Capacity (B/SD) Vacuum Distillation Downstream Charge Capacity (B/SD) Thermal Cracking Downstream Charge Capacity (B/SD) Thermal Cracking Total Coking Downstream Charge Capacity (B/SD) Thermal Cracking Delayed Coking Downstream Charge Capacity (B/SD Thermal Cracking Fluid Coking Downstream Charge Capacity (B/SD) Thermal Cracking Visbreaking Downstream Charge Capacity (B/SD) Thermal Cracking Other/Gas Oil Charge Capacity (B/SD) Catalytic Cracking Fresh Feed Charge Capacity (B/SD) Catalytic Cracking Recycle Charge Capacity (B/SD) Catalytic Hydro-Cracking Charge Capacity (B/SD) Catalytic Hydro-Cracking Distillate Charge Capacity (B/SD) Catalytic Hydro-Cracking Gas Oil Charge Capacity (B/SD) Catalytic Hydro-Cracking Residual Charge Capacity (B/SD) Catalytic Reforming Charge Capacity (B/SD) Catalytic Reforming Low Pressure Charge Capacity (B/SD) Catalytic Reforming High Pressure Charge Capacity (B/SD) Catalytic Hydrotreating/Desulfurization Charge Capacity (B/SD) Catalytic Hydrotreating Naphtha/Reformer Feed Charge Cap (B/SD) Catalytic Hydrotreating Gasoline Charge Capacity (B/SD) Catalytic Hydrotreating Heavy Gas Oil Charge Capacity (B/SD) Catalytic Hydrotreating Distillate Charge Capacity (B/SD) Catalytic Hydrotreating Kerosene/Jet Fuel Charge Capacity (B/SD) Catalytic Hydrotreating Diesel Fuel Charge Capacity (B/SD) Catalytic Hydrotreating Other Distillate Charge Capacity (B/SD) Catalytic Hydrotreating Residual/Other Charge Capacity (B/SD) Catalytic Hydrotreating Residual Charge Capacity (B/SD) Catalytic Hydrotreating Other Oils Charge Capacity (B/SD) Fuels Solvent Deasphalting Charge Capacity (B/SD) Catalytic Reforming Downstream Charge Capacity (B/CD) Total Coking Downstream Charge Capacity (B/CD) Catalytic Cracking Fresh Feed Downstream Charge Capacity (B/CD) Catalytic Hydro-Cracking Downstream Charge Capacity (B/CD) Period:

182

Evaluation of the MMCLIFE 3.0 code in predicting crack growth in titanium aluminide composites  

SciTech Connect (OSTI)

Crack growth and fatigue life predictions made with the MMCLIFE 3.0 code are compared to test data for unidirectional, continuously reinforced SCS-6/Ti-14Al-21Nb (wt pct) composite laminates. The MMCLIFE 3.0 analysis package is a design tool capable of predicting strength and fatigue performance in metal matrix composite (MMC) laminates. The code uses a combination of micromechanic lamina and macromechanic laminate analyses to predict stresses and uses linear elastic fracture mechanics to predict crack growth. The crack growth analysis includes a fiber bridging model to predict the growth of matrix flaws in 0{degree} laminates and is capable of predicting the effects of interfacial shear stress and thermal residual stresses. The code has also been modified to include edge-notch flaws in addition to center-notch flaws. The model was correlated with constant amplitude, isothermal data from crack growth tests conducted on 0- and 90{degree} SCS-6/Ti-14-21 laminates. Spectrum fatigue tests were conducted, which included dwell times and frequency effects. Strengths and areas for improvement for the analysis are discussed.

Harmon, D. [Boeing Co., St. Louis, MO (United States); Larsen, J.M. [Materials and Mfg. Directorate, Wright-Patterson AFB, OH (United States). Air Force Research Lab.; Peralta, A.; Hall, J.A. [Allied Signal Engines, Phoenix, AZ (United States)

1999-02-01T23:59:59.000Z

183

Linking Grain Boundary Structure and Composition to Intergranular Stress Corrosion Cracking of Austenitic Stainless Steels  

SciTech Connect (OSTI)

Grain boundary structure and composition is assessed in austenitic stainless steels along with its influence on intergranular stress corrosion cracking (IGSCC) in high-temperature water. Brief examples are presented illustrating effects of grain boundary character and segregation on behavior in specific light-water-reactor environments. Although grain boundary engineering can produce an increased fraction of special boundaries in austenitic stainless alloys, practical benefits depend on the boundary orientation distribution. It is critical to recognize that only coherent sigma 3s appear to be resistant to SCC and the behavior of other low sigma boundaries is uncertain. Grain boundary composition can have a dominant effect on IGSCC under certain conditions, but altered interfacial chemistry is not required for cracking. In high-potential oxidizing environments, IGSCC susceptibility is a direct function of the boundary Cr concentration. Non-equilibrium thermal segregation of Cr and Mo is often present in millannealed stainless steels and may influence cracking susceptibility. This initial grain boundary composition alters subsequent radiation-induced segregation and delays irradiation-assisted SCC susceptibility to higher doses. Other alloying elements and impurities in 300-series stainless steels have been seen to enrich grain boundaries, but few have any significant impact on IGSCC susceptibility. One exception is Si that strongly segregates during irradiation. recent results suggest that Si may accelerate crack propagation in both low- and high-potential water environments. Critical research is still needed to isolate individual grain boundary characteristics and quantitatively link to IGSCC.

Bruemmer, Stephen M.

2004-08-10T23:59:59.000Z

184

Fatigue Enhancement of Undersized, Drilled Crack-Arrest Holes  

E-Print Network [OSTI]

Fatigue cracks occur in steel bridges from repeated loads. If allowed to continue to grow, eventually the fatigue cracks will require either expensive repairs or reduction of traffic loads on the bridge, or they may lead ...

Simmons, Gary Gene

2013-12-31T23:59:59.000Z

185

Dynamical fracture instabilities due to local hyperelasticity at crack tips  

Science Journals Connector (OSTI)

... a crack propagating through a brittle material increases, a dynamical instability leads to an increased roughening of the fracture surface. Cracks moving at low speeds create atomically flat mirror-like ...

Markus J. Buehler; Huajian Gao

2006-01-19T23:59:59.000Z

186

Reflective cracking of shear keys in multi-beam bridges  

E-Print Network [OSTI]

strength to resist cracking from vehicular loads, but uneven temperature changes and shrinkage strains cause high tensile stresses in the shear key regions and lead to reflective cracking. The analyses showed the highest stresses were often times near...

Sharpe, Graeme Peter

2009-06-02T23:59:59.000Z

187

Digital radiographic systems detect boiler tube cracks  

SciTech Connect (OSTI)

Boiler water wall leaks have been a major cause of steam plant forced outages. But conventional nondestructive evaluation techniques have a poor track record of detecting corrosion fatigue cracking on the inside surface of the cold side of waterwall tubing. EPRI is performing field trials of a prototype direct-digital radiographic system that promises to be a game changer. 8 figs.

Walker, S. [EPRI, Charlotte, NC (United States)

2008-06-15T23:59:59.000Z

188

NORTHWESTERN UNIVERSITY Autonomous Crack Comparometer Phase II  

E-Print Network [OSTI]

program between the two universities. Thanks are also given to the staff of the Infrastructure Technology Institute and in particular Dan Marron for all his advice and assistance during the project. I would like that daily and weekly weather related crack displacements are greater than those produced by dynamic events

189

CRACKING OF PIc NUCLEAR CONTAINMENT STRUCTURES  

E-Print Network [OSTI]

CRACKING OF PIc NUCLEAR CONTAINMENT STRUCTURES By Sami H. Rizkalla,l Sidney H. Simmonds': and James structures for some Canadian nuclear reactors consist of a heavy concrete base, a cylindrical wall, a ring the design accident pressure. This would result in the walls and dome of the containment being stressed

190

Feedback algorithm for simulation of multi-segmented cracks  

SciTech Connect (OSTI)

In this paper, a method for obtaining a three dimensional crack model from a radiographic image is discussed. A genetic algorithm aiming at close simulation of crack's shape is presented. Results obtained with genetic algorithm are compared to those achieved in authors' previous work. The described algorithm has been tested on both simulated and real-life cracks.

Chady, T.; Napierala, L. [Department of Electrical and Computer Engineering, Faculty of Electrical Engineering, West Pomeranian University of Technology, al. Piastow 17, 70-310 Szczecin (Poland)

2011-06-23T23:59:59.000Z

191

ESTABLISHEMENT OF CRACK INDEXES BY ELECTRICAL APPARENT RESISTIVITY DATA  

E-Print Network [OSTI]

ESTABLISHEMENT OF CRACK INDEXES BY ELECTRICAL APPARENT RESISTIVITY DATA A. Samouelian (1,2), I is indeed well adapted to recognize the electrical resistant signature of crack filled by air during-destructive geophysical methods permits a 3D temporal monitoring of the cracking patterns. Electrical resis- tivity

Boyer, Edmond

192

Fracture toughness and fatigue crack growth characteristics of nanotwinned copper  

E-Print Network [OSTI]

fracture and subcritical fatigue crack growth life. Possible mechanistic origins of these trends and the resistance to stable subcritical crack growth under mono- tonic and cyclic loading, especially at lowerFracture toughness and fatigue crack growth characteristics of nanotwinned copper A. Singh a,1 , L

Suresh, Subra

193

Dynamic crack response to a localized shear pulse perturbation in brittle amorphous materials: on crack surface roughening  

Science Journals Connector (OSTI)

Linear Elastic Fracture Mechanics (LEFM) provides a coherent framework to evaluate quantitatively the energy flux released at the tip of a growing crack. However, the way in which the crack chooses its path in re...

D. Bonamy; K. Ravi-Chandar

2005-07-01T23:59:59.000Z

194

Characterization of cracking restraint at sawcut joints using the German Cracking Frame  

E-Print Network [OSTI]

. Cracks Follow Capillary Channels . . 3. Warping stress coefficients (from Bradbury). , 4. Cracks follow capillary channels. 5. Schematic representation of the slab instrumentation. . . . 6. Weather data on the day the bike trail concrete was laid... the curling stresses caused by temperature differentials through the slab, and are used to find the total stress due to bending, in a slab. The Bradbury curling coefficient (Figure 3) was developed by Bradbury in 1938 based on Westergaard analysis. Bradbury...

Vepakomma, Shilpa

2012-06-07T23:59:59.000Z

195

Cracking catalyst and method of producing the same  

SciTech Connect (OSTI)

This invention relates to exchanged ammoniated cogels having improved catalytic activity and process for producing the same.

Alafandi, H.; Stamires, D.

1980-12-16T23:59:59.000Z

196

Evolving crack patterns in thin films with the extended finite element method  

E-Print Network [OSTI]

-exist in the film. To describe subcritical crack growth, we prescribe a kinetic law that relates the crack velocity is susceptible to subcritical cracking, obeying a kinetic law that relates the velocity of each crack to its Elsevier Science Ltd. All rights reserved. Keywords: Crack patterns; Subcritical cracking; Thin films

Suo, Zhigang

197

Catalytic gasification of tars from a dumping site  

Science Journals Connector (OSTI)

The work deals with catalytic gasification, pyrolysis and non-catalytic gasification of tar from an industrial dumping site. ... were carried out in a vertical stainless steel gasification reactor at 800 °C. Crus...

Lukáš Gašparovi?; Lukáš Šugár…

2013-10-01T23:59:59.000Z

198

Fracture Modeling of Crack Propagation in Wood and Wood Composites Including Crack Tip Processes and Fiber Bridging Mechanics  

E-Print Network [OSTI]

1 Fracture Modeling of Crack Propagation in Wood and Wood Composites Including Crack Tip Processes and Fiber Bridging Mechanics J. A. Nairn, N. Matsumoto Wood Science & Engineering, Oregon State University wood and wood composites develop process zones often consisting of fibers bridging the crack surfaces

Nairn, John A.

199

Cleavage crack-tip deformation in single-crystal zinc  

Science Journals Connector (OSTI)

Dislocation distribution ahead of a cleavage crack tip in single crystal Zn is observed by using the etch pit technique. The results show that the distribution has the feature predicted by the DFZ models, and both X1, the distance from the crack tip to the first dislocation and N0, the total number of dislocations ahead of the crack tip, agree with Majumdar and Burns's DFZ theory. The problems of dislocation emission from the crack tip and dislocation shielding effects on the crack tip are also discussed based on the experimental results.

Fu Ran; Q Y Long; T Y Zhang; C W Lung

1989-01-01T23:59:59.000Z

200

Rapid Deployment of Rich Catalytic Combustion  

SciTech Connect (OSTI)

The overall objective of this research under the Turbines Program is the deployment of fuel flexible rich catalytic combustion technology into high-pressure ratio industrial gas turbines. The resulting combustion systems will provide fuel flexibility for gas turbines to burn coal derived synthesis gas or natural gas and achieve NO{sub x} emissions of 2 ppmvd or less (at 15 percent O{sub 2}), cost effectively. This advance will signify a major step towards environmentally friendly electric power generation and coal-based energy independence for the United States. Under Phase 1 of the Program, Pratt & Whitney (P&W) performed a system integration study of rich catalytic combustion in a small high-pressure ratio industrial gas turbine with a silo combustion system that is easily scalable to a larger multi-chamber gas turbine system. An implementation plan for this technology also was studied. The principal achievement of the Phase 1 effort was the sizing of the catalytic module in a manner which allowed a single reactor (rather than multiple reactors) to be used by the combustion system, a conclusion regarding the amount of air that should be allocated to the reaction zone to achieve low emissions, definition of a combustion staging strategy to achieve low emissions, and mechanical integration of a Ceramic Matrix Composite (CMC) combustor liner with the catalytic module.

Richard S. Tuthill

2004-06-10T23:59:59.000Z

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


201

Catalytic wet oxidation of phenolic wastes  

E-Print Network [OSTI]

Possible catalyst deactivation problems High capital, low operating Supercritical water oxidation (SCWO) Feasible only at high organic concentra- tions High Fast reaction, complete oxidation Severe reaction conditions, canosion problems... of milder reaction conditions and is much less energy intensive. Thus, catalytic wet oxidation would be an alternative to solvent extraction, supercritical water oxidation, homogeneous oxidation, and incineration. It should also be feasible at low...

Thomas, Brook James

1995-01-01T23:59:59.000Z

202

Catalytic Partial Oxidation Pilot Plant Study  

Science Journals Connector (OSTI)

Foster Wheeler Corporation, 585 North Dairy Ashford Street, Houston, Texas 77079 ... This is accomplished in this study with a new reactor system named the catalytic hot oxygen reactor (CHOR). ... Studying the integration of the reactor with the rest of the plant and developing detailed process economics in parallel with the system development are necessary. ...

Vasilis Papavassiliou; Perry Pacouloute; KT Wu; Raymont Drnevich; Dionisios Vlachos; John Hemmings; Leo Bonnel

2009-11-24T23:59:59.000Z

203

Remediation of water contamination using catalytic technologies  

Science Journals Connector (OSTI)

Remediation of contaminated ground and underground water is becoming a critical issue in Europe and worldwide. We discuss here the role of catalysis in water remediation, with reference to two specific examples of catalytic water remediation technologies: (i) the elimination of nitrate and pesticides from water contaminated as a result of agricultural practices and (ii) the conversion of methyl tert-butyl ether (MTBE) in contaminated underground water. Of particular interest is a technology based on catalytic membranes for remediation of water contaminated by nitrate, which offers various advantages with respect to conventional technologies. Using a Pd-Cu-based catalytic membrane, a reaction temperature below 15 °C, a mixed 4:1 CO2:H2 feed and controlling bulk solution pH by \\{HCl\\} addition, it is possible to obtain a nitrate conversion higher than 80% even with ammonium ion formation below 0.5 ppm, i.e. the maximum concentration allowed to meet the requirements for drinking water quality. In MTBE conversion in contaminated underground water, acid zeolites with suitable pore structures (channel structure and pore openings) such as H-ZSM-5 and H-BEA can be used as catalytic permeable reactive barriers for in situ remediation. These zeolites not only act as adsorbents for both MTBE and its reaction products, but also effectively catalyze the hydrolysis of MTBE to t-butyl alcohol (TBA) and methanol (MeOH) which then can be rapidly biodegraded by indigenous microorganisms.

Gabriele Centi; Siglinda Perathoner

2003-01-01T23:59:59.000Z

204

Effect of aging of the pillaring reagent on the microstructure and cracking activity of pillared clay  

SciTech Connect (OSTI)

Pillared interlayer clay (PILC) is formed by exchanging large hydroxyaluminum polycations into the interlayer of a smectite clay such as montmorillonite, which is made up of sheet-like silica/alumina layers. Calcination of the exchanged clay gives a well dispersed array of metal oxide clumps (i.e., pillars) bonded top and bottom to the silica/alumina layers of the clay. The permanent separation of the clay layers gives an 8 to 10-fold increase in surface area, from 30 to 250-300 m{sup 2}/g, and a microporous structure similar to but less constrained than that of zeolites. Recently, there has been an increased interest in the use of these clays as cracking catalysts. For example, pillared clays have been shown to be an active cracking catalyst for both single component and gas oil feeds. PILC's also lead to both higher light cycle oil (LCO) and coke yields than conventional cracking catalysts. Commercially available, metal-hydrolyzed hydroxyaluminum solutions containing chlorhydrol, A1{sub 2}(OH){sub 5}C1.2H{sub 2}O, have been used as one source of the polycation solution. The approach of these hydrolyzed polycation solutions to equilibrium is known as aging. During the aging process certain polycationic species disappear from the solution and new species are formed. For this reason, the aging process can have a significant influence on the properties of the pillared clays. The objective of this work was to determine how the physical and catalytic properties of the pillared clay depend on the aging of dilute cholorhydrol solutions.

Harris, J.R. (Phillips Petroleum Company, Bartlesville, OK (USA))

1987-08-01T23:59:59.000Z

205

The Stress Corrosion Crack Growth Rate of Alloy 600 Heat Affected Zones Exposed to High Purity Water  

SciTech Connect (OSTI)

Grain boundary chromium carbides improve the resistance of nickel based alloys to primary water stress corrosion cracking (PWSCC). However, in weld heat affected zones (HAZ's), thermal cycles from fusion welding can solutionize beneficial grain boundary carbides, produce locally high residual stresses and strains, and promote PWSCC. The present research investigates the crack growth rate of an A600 HAZ as a function of test temperature. The A600 HAZ was fabricated by building up a gas-tungsten-arc-weld deposit of EN82H filler metal onto a mill-annealed A600 plate. Fracture mechanics based, stress corrosion crack growth rate testing was performed in high purity water between 600 F and 680 F at an initial stress intensity factor of 40 ksi {radical}in and at a constant electrochemical potential. The HAZ samples exhibited significant SCC, entirely within the HAZ at all temperatures tested. While the HAZ samples showed the same temperature dependence for SCC as the base material (HAZ: 29.8 {+-} 11.2{sub 95%} kcal/mol vs A600 Base: 35.3 {+-} 2.58{sub 95%} kcal/mol), the crack growth rates were {approx} 30X faster than the A600 base material tested at the same conditions. The increased crack growth rates of the HAZ is attributed to fewer intergranular chromium rich carbides and to increased plastic strain in the HAZ as compared to the unaffected base material.

George A. Young; Nathan Lewis

2003-04-05T23:59:59.000Z

206

Novel Fast Pyrolysis/Catalytic Technology for the Production of Stable Upgraded Liquids  

SciTech Connect (OSTI)

The objective of the proposed research is the demonstration and development of a novel biomass pyrolysis technology for the production of a stable bio-oil. The approach is to carry out catalytic hydrodeoxygenation (HDO) and upgrading together with pyrolysis in a single fluidized bed reactor with a unique two-level design that permits the physical separation of the two processes. The hydrogen required for the HDO will be generated in the catalytic section by the water-gas shift reaction employing recycled CO produced from the pyrolysis reaction itself. Thus, the use of a reactive recycle stream is another innovation in this technology. The catalysts will be designed in collaboration with BASF Catalysts LLC (formerly Engelhard Corporation), a leader in the manufacture of attrition-resistant cracking catalysts. The proposed work will include reactor modeling with state-of-the-art computational fluid dynamics in a supercomputer, and advanced kinetic analysis for optimization of bio-oil production. The stability of the bio-oil will be determined by viscosity, oxygen content, and acidity determinations in real and accelerated measurements. A multi-faceted team has been assembled to handle laboratory demonstration studies and computational analysis for optimization and scaleup.

Ted Oyama, Foster Agblevor, Francine Battaglia, Michael Klein

2013-01-18T23:59:59.000Z

207

Treating isopropyl alcohol by a regenerative catalytic oxidizer  

Science Journals Connector (OSTI)

Regenerative catalytic oxidizer (RCO) can be conveniently used to control emissions of volatile organic compounds (VOCs), because of their thermal recovery efficiency (TRE), low fuel cost and high oxidation. In this work, catalysts with various metal weight loadings were prepared by deposition–precipitation, wet impregnation and incipient impregnation to treat isopropyl alcohol (IPA). We used the excellent catalytic performance in a pilot RCO to test IPA oxidation performance under various conditions. The best catalyst was selected and its TRE, bed temperature variations, pressure drops and selectivity of the catalyst were more widely discussed. The results demonstrate that the optimal catalyst was prepared by wet impregnation with 20 wt.% metal on ceramic honeycomb (CH). 20 wt.% Cu–Co/(CH) catalyst was the best catalyst used in a RCO because it was effective in treating IPA, with a CO2 yield of up to 95% at a heating zone temperature (Tset) = 400 °C under various conditions. It also had the largest tolerance of variations in inlet IPA concentration and gas velocity (Ug). This 20 wt.% Cu–Co/(CH) catalyst in a RCO performed well in terms of TRE, pressure drop and selectivity to CO2. The TRE range in a RCO was from 87.8 to 91.2% under various conditions, and decreased as Ug increased in a fixed Tset. The pressure drop increased with Ug and Tset. The selectivity to CO2 increased to over 95% at 300 °C, and that to propene remained at 2–5% from 200 to 400 °C. Finally, the stability test results indicated that the 20 wt.% Cu–Co/(CH) catalyst was very stable at various CO2 yields and temperatures.

Jie-Chung Lou; Shih-Wei Huang

2008-01-01T23:59:59.000Z

208

Modeling a Catalytic Reactor for Hydrotreating of Straight-Run Gas Oil Blended with Fluid Catalytic Cracking Naphtha and Light Cycle Oil: Influence of Vapor–Liquid Equilibrium  

Science Journals Connector (OSTI)

Model results were validated using the industrial test run data, and very good predictions of overall sulfur conversion and reactor temperature were obtained. ...

Ivana M. Mijatovi?; Sandra B. Glisic; Aleksandar M. Orlovi?

2014-11-17T23:59:59.000Z

209

Process for magnetic beneficiating petroleum cracking catalyst  

DOE Patents [OSTI]

A process for beneficiating a particulate zeolite petroleum cracking catalyst having metal values in excess of 1000 ppm nickel equivalents. The particulate catalyst is passed through a magnetic field in the range of from about 2 Tesla to about 5 Tesla generated by a superconducting quadrupole open-gradient magnetic system for a time sufficient to effect separation of said catalyst into a plurality of zones having different nickel equivalent concentrations. A first zone has nickel equivalents of about 6,000 ppm and greater, a second zone has nickel equivalents in the range of from about 2000 ppm to about 6000 ppm, and a third zone has nickel equivalents of about 2000 ppm and less. The zones of catalyst are separated and the second zone material is recycled to a fluidized bed of zeolite petroleum cracking catalyst. The low nickel equivalent zone is treated while the high nickel equivalent zone is discarded.

Doctor, Richard D. (Lisle, IL)

1993-01-01T23:59:59.000Z

210

Process for magnetic beneficiating petroleum cracking catalyst  

DOE Patents [OSTI]

A process is described for beneficiating a particulate zeolite petroleum cracking catalyst having metal values in excess of 1000 ppm nickel equivalents. The particulate catalyst is passed through a magnetic field in the range of from about 2 Tesla to about 5 Tesla generated by a superconducting quadrupole open-gradient magnetic system for a time sufficient to effect separation of said catalyst into a plurality of zones having different nickel equivalent concentrations. A first zone has nickel equivalents of about 6,000 ppm and greater, a second zone has nickel equivalents in the range of from about 2000 ppm to about 6000 ppm, and a third zone has nickel equivalents of about 2000 ppm and less. The zones of catalyst are separated and the second zone material is recycled to a fluidized bed of zeolite petroleum cracking catalyst. The low nickel equivalent zone is treated while the high nickel equivalent zone is discarded. 1 figures.

Doctor, R.D.

1993-10-05T23:59:59.000Z

211

Static strength assessment of cracked tubular joints  

SciTech Connect (OSTI)

Results from a number of investigations on the ultimate capacity of cracked tubular joints are available. A comparison of the results with predictions from parametric equations for the static strength capacity of intact joints indicates that the presence of a defect can have a significant influence on the joint capacity. The data, which were obtained from experiments on small-scale and large-scale tests and numerical analyses, are assessed in this paper. A range of tubular joint geometries containing surface and through-thickness cracks are considered. The data are assessed with respect to characteristic static strength predictions and fracture mechanics predictions based on the use of the Failure Assessment Diagram approach. Finally, an outline of current research in this area is presented.

Stacey, A.; Sharp, J.V. [Health and Safety Executive, London (United Kingdom). Offshore Safety Div.; Nichols, N.W. [AEA Technology, Culham (United Kingdom)

1996-12-01T23:59:59.000Z

212

Fluid-Bed Testing of Greatpoint Energy's Direct Oxygen Injection Catalytic Gasification Process for Synthetic Natural Gas and Hydrogen Coproduction Year 6 - Activity 1.14 - Development of a National Center for Hydrogen Technology  

SciTech Connect (OSTI)

The GreatPoint Energy (GPE) concept for producing synthetic natural gas and hydrogen from coal involves the catalytic gasification of coal and carbon. GPE’s technology “refines” coal by employing a novel catalyst to “crack” the carbon bonds and transform the coal into cleanburning methane (natural gas) and hydrogen. The GPE mild “catalytic” gasifier design and operating conditions result in reactor components that are less expensive and produce pipeline-grade methane and relatively high purity hydrogen. The system operates extremely efficiently on very low cost carbon sources such as lignites, subbituminous coals, tar sands, petcoke, and petroleum residual oil. In addition, GPE’s catalytic coal gasification process eliminates troublesome ash removal and slagging problems, reduces maintenance requirements, and increases thermal efficiency, significantly reducing the size of the air separation plant (a system that alone accounts for 20% of the capital cost of most gasification systems) in the catalytic gasification process. Energy & Environmental Research Center (EERC) pilot-scale gasification facilities were used to demonstrate how coal and catalyst are fed into a fluid-bed reactor with pressurized steam and a small amount of oxygen to “fluidize” the mixture and ensure constant contact between the catalyst and the carbon particles. In this environment, the catalyst facilitates multiple chemical reactions between the carbon and the steam on the surface of the coal. These reactions generate a mixture of predominantly methane, hydrogen, and carbon dioxide. Product gases from the process are sent to a gas-cleaning system where CO{sub 2} and other contaminants are removed. In a full-scale system, catalyst would be recovered from the bottom of the gasifier and recycled back into the fluid-bed reactor. The by-products (such as sulfur, nitrogen, and CO{sub 2}) would be captured and could be sold to the chemicals and petroleum industries, resulting in near-zero hazardous air or water pollution. This technology would also be conducive to the efficient coproduction of methane and hydrogen while also generating a relatively pure CO{sub 2} stream suitable for enhanced oil recovery (EOR) or sequestration. Specific results of bench-scale testing in the 4- to 38-lb/hr range in the EERC pilot system demonstrated high methane yields approaching 15 mol%, with high hydrogen yields approaching 50%. This was compared to an existing catalytic gasification model developed by GPE for its process. Long-term operation was demonstrated on both Powder River Basin subbituminous coal and on petcoke feedstocks utilizing oxygen injection without creating significant bed agglomeration. Carbon conversion was greater than 80% while operating at temperatures less than 1400°F, even with the shorter-than-desired reactor height. Initial designs for the GPE gasification concept called for a height that could not be accommodated by the EERC pilot facility. More gas-phase residence time should allow the syngas to be converted even more to methane. Another goal of producing significant quantities of highly concentrated catalyzed char for catalyst recovery and material handling studies was also successful. A Pd–Cu membrane was also successfully tested and demonstrated to produce 2.54 lb/day of hydrogen permeate, exceeding the desired hydrogen permeate production rate of 2.0 lb/day while being tested on actual coal-derived syngas that had been cleaned with advanced warm-gas cleanup systems. The membranes did not appear to suffer any performance degradation after exposure to the cleaned, warm syngas over a nominal 100-hour test.

Swanson, Michael; Henderson, Ann

2012-04-01T23:59:59.000Z

213

Structures for dense, crack free thin films  

DOE Patents [OSTI]

The process described herein provides a simple and cost effective method for making crack free, high density thin ceramic film. The steps involve depositing a layer of a ceramic material on a porous or dense substrate. The deposited layer is compacted and then the resultant laminate is sintered to achieve a higher density than would have been possible without the pre-firing compaction step.

Jacobson, Craig P. (Lafayette, CA); Visco, Steven J. (Berkeley, CA); De Jonghe, Lutgard C. (Lafayette, CA)

2011-03-08T23:59:59.000Z

214

Catalytic igniters and their use to ignite lean hydrogen-air mixtures  

DOE Patents [OSTI]

A catalytic igniter which can ignite a hydrogen-air mixture as lean as 5.5% hydrogen with induction times ranging from 20 s to 400 s, under conditions which may be present during a loss-of-liquid-coolant accident at a light water nuclear reactor comprises (a) a perforate catalytically active substrate, such as a platinum coated ceramic honeycomb or wire mesh screen, through which heated gases produced by oxidation of the mixture can freely flow and (b) a plurality of thin platinum wires mounted in a thermally conductive manner on the substrate and positioned thereon so as to be able to receive heat from the substrate and the heated gases while also in contact with unoxidized gases.

McLean, William J. (Oakland, CA); Thorne, Lawrence R. (Livermore, CA); Volponi, Joanne V. (Livermore, CA)

1988-01-01T23:59:59.000Z

215

High pressure test results of a catalytic combustor for gas turbine  

SciTech Connect (OSTI)

Recently, the use of gas turbine systems, such as combined cycle and cogeneration systems, has gradually increased in the world. But even when a clean fuel such as LNG (liquefied natural gas) is used, thermal NO{sub x} is generated in the high temperature gas turbine combustion process. The NO{sub x} emission from gas turbines is controlled through selective catalytic reduction processes (SCR) in the Japanese electric industry. If catalytic combustion could be applied to the combustor of the gas turbine, it is expected to lower NO{sub x} emission more economically. Under such high temperature and high pressure conditions, as in the gas turbine, however, the durability of the catalyst is still insufficient. So it prevents the realization of a high temperature catalytic combustor. To overcome this difficulty, a catalytic combustor combined with premixed combustion for a 1,300 C class gas turbine was developed. In this method, catalyst temperature is kept below 1,000 C, and a lean premixed gas is injected into the catalytic combustion gas. As a result, the load on the catalyst is reduced and it is possible to prevent the catalyst deactivation. After a preliminary atmospheric test, the design of the combustion was modified and a high pressure combustion test was conducted. As a result, it was confirmed that NO{sub x} emission was below 10 ppm (at 16 percent O{sub 2}) at a combustor outlet gas temperature of 1,300 C and that the combustion efficiency was almost 100%. This paper presents the design features and test results of the combustor.

Fujii, T.; Ozawa, Y.; Kikumoto, S.; Sato, M. [Central Research Inst. of Electric Power Industry, Yokosuka, Kanagawa (Japan); Yuasa, Y.; Inoue, H. [Kansai Electric Power Co., Inc., Amagasaki, Hyogo (Japan)

1998-07-01T23:59:59.000Z

216

Method and apparatus for a catalytic firebox reactor  

DOE Patents [OSTI]

A catalytic firebox reactor employing an exothermic catalytic reaction channel and multiple cooling conduits for creating a partially reacted fuel/oxidant mixture. An oxidation catalyst is deposited on the walls forming the boundary between the multiple cooling conduits and the exothermic catalytic reaction channel, on the side of the walls facing the exothermic catalytic reaction channel. This configuration allows the oxidation catalyst to be backside cooled by any fluid passing through the cooling conduits. The heat of reaction is added to both the fluid in the exothermic catalytic reaction channel and the fluid passing through the cooling conduits. After discharge of the fluids from the exothermic catalytic reaction channel, the fluids mix to create a single combined flow. A further innovation in the reactor incorporates geometric changes in the exothermic catalytic reaction channel to provide streamwise variation of the velocity of the fluids in the reactor.

Smith, Lance L. (North Haven, CT); Etemad, Shahrokh (Trumbull, CT); Ulkarim, Hasan (Hamden, CT); Castaldi, Marco J. (Bridgeport, CT); Pfefferle, William C. (Madison, CT)

2001-01-01T23:59:59.000Z

217

Modeling and Optimization of Direct Chill Casting to Reduce Ingot Cracking  

SciTech Connect (OSTI)

Approximately 68% of the aluminum produced in the United States is first cast into ingots prior to further processing into sheet, plate, extrusions, or foil. The direct chill (DC) semi-continuous casting process has been the mainstay of the aluminum industry for the production of ingots due largely to its robust nature and relative simplicity. Though the basic process of DC casting is in principle straightforward, the interaction of process parameters with heat extraction, microstructural evolution, and development of solidification stresses is too complex to analyze by intuition or practical experience. One issue in DC casting is the formation of stress cracks [1-15]. In particular, the move toward larger ingot cross-sections, the use of higher casting speeds, and an ever-increasing array of mold technologies have increased industry efficiencies but have made it more difficult to predict the occurrence of stress crack defects. The Aluminum Industry Technology Roadmap [16] has recognized the challenges inherent in the DC casting process and the control of stress cracks and selected the development of 'fundamental information on solidification of alloys to predict microstructure, surface properties, and stresses and strains' as a high-priority research need, and the 'lack of understanding of mechanisms of cracking as a function of alloy' and 'insufficient understanding of the aluminum solidification process', which is 'difficult to model', as technology barriers in aluminum casting processes. The goal of this Aluminum Industry of the Future (IOF) project was to assist the aluminum industry in reducing the incidence of stress cracks from the current level of 5% to 2%. Decreasing stress crack incidence is important for improving product quality and consistency as well as for saving resources and energy, since considerable amounts of cast metal could be saved by eliminating ingot cracking, by reducing the scalping thickness of the ingot before rolling, and by eliminating butt sawing. Full-scale industrial implementation of the results of the proposed research would lead to energy savings in excess of 6 trillion Btu by the year 2020. The research undertaken in this project aimed to achieve this objective by a collaboration of industry, university, and national laboratory personnel through Secat, Inc., a consortium of aluminum companies. During the four-year project, the industrial partners and the research team met in 16 quarterly meetings to discuss research results and research direction. The industrial partners provided guidance, facilities, and experience to the research team. The research team went to two industrial plants to measure temperature distributions in commercial 60,000-lb DC casting ingot production. The project focused on the development of a fundamental understanding of ingot cracking and detailed models of thermal conditions, solidification, microstructural evolution, and stress development during the initial transient in DC castings of the aluminum alloys 3004 and 5182. The microstructure of the DC casting ingots was systematically characterized. Carefully designed experiments were carried out at the national laboratory and university facilities as well as at the industrial locations using the industrial production facilities. The advanced computational capabilities of the national laboratories were used for thermodynamic and kinetic simulations of phase transformation, heat transfer and fluid flow, solidification, and stress-strain evolution during DC casting. The achievements of the project are the following: (1) Identified the nature of crack formation during DC casting; (2) Developed a novel method for determining the mechanical properties of an alloy at the nonequilibrium mushy zone of the alloy; (3) Measured heat transfer coefficients (HTCs) between the solidifying ingot and the cooling water jet; (4) Determined the material constitutive model at high temperatures; and (5) Developed computational capabilities for the simulation of cracking formation in DC casting ingot. The models and the database de

Das, S.K.; Ningileri, S.; Long, Z.; Saito, K.; Khraisheh, M.; Hassan, M.H.; Kuwana, K.; Han, Q.; Viswanathan, S.; Sabau, A.S.; Clark, J.; Hyrn, J. (ANL)

2006-08-15T23:59:59.000Z

218

Catalytic fast pyrolysis of lignocellulosic biomass  

SciTech Connect (OSTI)

Increasing energy demand, especially in the transportation sector, and soaring CO2 emissions necessitate the exploitation of renewable sources of energy. Despite the large variety of new energy Q3 carriers, liquid hydrocarbon still appears to be the most attractive and feasible form of transportation fuel taking into account the energy density, stability and existing infrastructure. Biomass is an abundant, renewable source of energy; however, utilizing it in a cost-effective way is still a substantial challenge. Lignocellulose is composed of three major biopolymers, namely cellulose, hemicellulose and lignin. Fast pyrolysis of biomass is recognized as an efficient and feasible process to selectively convert lignocellulose into a liquid fuel—bio-oil. However bio-oil from fast pyrolysis contains a large amount of oxygen, distributed in hundreds of oxygenates. These oxygenates are the cause of many negative properties, such as low heating values, high corrosiveness, high viscosity, and instability; they also greatly Q4 limit the application of bio-oil particularly as transportation fuel. Hydrocarbons derived from biomass are most attractive because of their high energy density and compatibility with the existing infrastructure. Thus, converting lignocellulose into transportation fuels via catalytic fast pyrolysis has attracted much attention. Many studies related to catalytic fast pyrolysis of biomass have been published. The main challenge of this process is the development of active and stable catalysts that can deal with a large variety of decomposition intermediates from lignocellulose. This review starts with the current understanding of the chemistry in fast pyrolysis of lignocellulose and focuses on the development of catalysts in catalytic fast pyrolysis. Recent progress in the experimental studies on catalytic fast pyrolysis of biomass is also summarized with the emphasis on bio-oil yields and quality.

Liu, Changjun; Wang, Huamin; Karim, Ayman M.; Sun, Junming; Wang, Yong

2014-11-21T23:59:59.000Z

219

Method and apparatus for generating a natural crack  

DOE Patents [OSTI]

A method and apparatus for generating a measurable natural crack includes forming a primary notch in the surface of a solid material. A nonsustained single pressure pulse is then generated in the vicinity of the primary notch, reuslting in the formation of a shock wave which travels through the material. The shock wave creates a measurable natural crack within the material which extends from the primary notch. The natural crack formed possesses predictable geometry, location and orientation.

Fulton, F.J.; Honodel, C.A.; Holman, W.R.; Weingart, R.C.

1982-05-06T23:59:59.000Z

220

Factors Affecting the Hydrogen Environment Assisted Cracking Resistance of an AL-Zn-Mg-(Cu) Alloy  

SciTech Connect (OSTI)

Precipitation hardenable Al-Zn-Mg alloys are susceptible to hydrogen environment assisted cracking (HEAC) when exposed to aqueous environments. In Al-Zn-Mg-Cu alloys, overaged tempers are used to increase HEAC resistance at the expense of strength but overaging has little benefit in low copper alloys. However, the mechanism or mechanisms by which overaging imparts HEAC resistance is poorly understood. The present research investigated hydrogen uptake, diffusion, and crack growth rate in 90% relative humidity (RH) air for both a commercial copper bearing Al-Zn-Mg-Cu alloy (AA 7050) and a low copper variant of this alloy in order to better understand the factors which affect HEAC resistance. Experimental methods used to evaluate hydrogen concentrations local to a surface and near a crack tip include nuclear reaction analysis (NRA), focused ion beam, secondary ion mass spectroscopy (FIB/SIMS) and thermal desorption spectroscopy (TDS). Results show that overaging the copper bearing alloys both inhibits hydrogen ingress from oxide covered surfaces and decreases the apparent hydrogen diffusion rates in the metal.

G.A. Young; J.R. Scully

2002-04-09T23:59:59.000Z

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


221

Vibration Diagnosis of Elastic Shafts with A Transverse Crack.  

E-Print Network [OSTI]

??Detection of the shaft crack in a rotating machine is one of the most challenging problems in equipment predictive maintenance. In the available literature, various… (more)

Cai, ZHONGYI

2011-01-01T23:59:59.000Z

222

White-Etching Crack Failure Overview, Tomography Analysis, and...  

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

White-Etching Crack Failure Overview, Tomography Analysis, and Test Development Presented by Aaron Greco of Argonne National Laboratory at the Wind Turbine Tribology Seminar 2014....

223

Investigation of White Etching Crack (WEC) Formation Mechanisms...  

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

Investigation of White Etching Crack (WEC) Formation Mechanisms Under Non-hydrogen Charged Test Conditions Presented by Alex Richardson, Afton Chemical (representing University of...

224

Hot Rolling Scrap Reduction through Edge Cracking and Surface...  

Broader source: Energy.gov (indexed) [DOE]

properties as a routine part of design. OEMs design typically with linear elastic fracture mechanics, isotropic crack direction criteria (maximum tensile stress) In...

225

Crack initiation and crack growth resistance of Ti-48Al-2Cr sheet material  

SciTech Connect (OSTI)

The present paper reports on the fracture toughness tests conducted on Ti-48Al-2Cr sheet material with near-gamma microstructure produced by hot rolling. Compact tension specimens were sectioned from sheet material and tested at room temperature to determine the fracture toughness and crack growth resistance curves. The deformation and fracture behavior were studied on tested specimens.

Dogan, B.; Schwalbe, K.H. [GKSS Research Centre, Geesthacht (Germany)] [GKSS Research Centre, Geesthacht (Germany); Clemens, H. [Plansee AG, Reutte (Austria)] [Plansee AG, Reutte (Austria)

1998-03-03T23:59:59.000Z

226

An evaluation of crack front effect on threshold and crack propagation  

SciTech Connect (OSTI)

That a through-thickness crack may exhibit over the entire fatigue crack propagation (FCP) regime morphological variations such as curvature, deviation and deflection appears to be very common. This effect is hereafter referred to as the crack front effect (CFE). It includes the practical consequence that when CFE occurs, local crack length, and hence the surface and the through-thickness data derived, tend to differ. Apparently, the difference should not be significant a least for thin specimens, for which data acquisition on one face suffices, and therefore, problems resulting from CFE can be neglected in certain cases. The authors became involved in the CFE problem while studying hysteresis effects in the threshold regime, particularly when post-threshold non-propagation was observed on the surface. In brief, the specimens had a section thickness of 4mm, i.e., relatively thin (B/W = 0.066), and according to the ASIM test recommendations the surface data should have been accurate. The major questions which arose were, however, whether surface and through-thickness effects are comparable, and how reliable surface observations are. Pure copper was chosen as the material since it exhibits a mixed mode fracture path, and thus should be inherently prone to yield CFE.

Vaidya, W.V.

1989-01-01T23:59:59.000Z

227

Corrosion-fatigue crack growth behavior of surface crack on AH36 TMCP steel weld in seawater  

SciTech Connect (OSTI)

Fatigue crack growth behavior in seawater of surface crack on the weld was studied with a structural steel, AH36, manufactured by the thermo-mechanical control process (TMCP). Crack growth rate was measured for the surface cracks located in different regions of weld, such as the heat affected zone, the weld metal and the base metal. Influence of the welding condition was investigated with the variation of heat inputs of 80, 120 and 180 kJ/cm. Electrochemical analysis of each region of the weld was also performed to investigate the corrosion behavior between the weld and the base metal.

Kweon, Y.G.; Jeong, H.D.; Chang, R.W. [Research Inst. of Industrial Science and Technology, Pohang (Korea, Republic of). Welding Research Center

1995-12-31T23:59:59.000Z

228

CIRCUMFERENTIAL MFL IN-LINE INSPECTION FOR CRACKS IN PIPELINES  

SciTech Connect (OSTI)

Circumferential MFL is a new implementation of a widely used technology that has potential to provide improved detection and quantification of axially oriented defects such as cracks, seam weld defects, mechanical damage, and groove corrosion. This implementation works by orienting the magnetic field around the pipe rather that along the axis. By orienting the magnetic field around the pipe (the circumferential direction), the axial defects that were magnetically transparent can disrupt more of the magnetic field and can be more easily detected. Initial implementations of circumferential MFL have found that flux leakage from cracks at the interior of the pipe is small, and the signals from cracks are difficult to detect. The objective of this project is to improve detection of cracks by changing the implementation along with using data from overlapping and complementary inspection techniques. Two technology enhancements were investigated: Combining high- and low-magnetization technology for stress detection; and Combining axial and circumferential MFL methods. Although a method combining high- and low-magnetization technology showed promise for characterizing gouges cause by third party excavation equipment, its commercial development was not successful for two reasons. First, the stress diminishes the crack signal, while the opening of the crack increases the signal. The stress-induced changes in flux leakage around cracks were small and any critical information on the severity of cracks and crack-like defects is difficult to distinguish from changes caused by the crack opening and other inspection variables. Second, it is difficult to magnetize pipe material in the circumferential direction. A relatively low, non-uniform magnetization level produced by the circumferential magnetizer makes detection of changes due to stress extremely difficult. This project also examined combining axial and circumferential MFL to improve crack detection and distinguish cracks for axially oriented volumetric defects. While successful results are presented in this report, circumferential MFL can only detect larger cracks. Even with the field aligned properly, circumferential MFL technology has difficulty detecting cracks on the outside surface that have the potential to grow to failure. Circumferential MFL can be used to detect many corrosion, mechanical damage, and crack defects. However, the detection capabilities and sizing accuracies may not be sufficient for all pipeline threats. Inspection tools that use more sophisticated technologies for detecting and sizing defects may have better performance capabilities, but will likely be expensive to operate. Circumferential MFL will be useful in identifying locations for detailed testing. While performance enhancements may be limited, circumferential MFL inspections will be part of the inspection process for many decades.

J.B. Nestleroth

2003-06-01T23:59:59.000Z

229

Final Technical Report [Development of Catalytic Alkylation and Fluoroalkylation Methods  

SciTech Connect (OSTI)

In the early stages of this DOE-funded research project, we sought to prepare and study a well-defined nickel-alkyl complex containing tridentate nitrogen donor ligands. We found that reaction of (TMEDA)NiMe2 (1) with terpyridine ligand cleanly led to the formation of (terpyridyl)NiMe (2), which we also determined to be an active alkylation catalyst. The thermal stability of 2 was unlike that seen for any of the active pybox ligands, and enabled a number of key studies on alkyl transfer reactions to be performed, providing new insights into the mechanism of nickel-mediated alkyl-alkyl cross-coupling reactions. In addition to the mechanistic studies, we showed that the terpyridyl nickel compounds can catalytically cross-couple alkyl iodides in yields up to 98% and bromides in yields up to 46 %. The yields for the bromides can be increased up to 67 % when the new palladium catalyst [(tpy’)Pd-Ph]I is used. The best route to the targeted [(tpy)NiBr] (1) was found to involve the comproportionation reaction of [(dme)NiBr{sub 2}] and [Ni(COD){sub 2}] in the presence of two equivalents of terpyridine. This reaction was driven to high yields of product formation (72 % isolated) by the precipitation of 1 from THF solvent.

Vicic, David A.

2014-05-01T23:59:59.000Z

230

Selective Catalytic Reduction and Exhaust Gas Recirculation Systems...  

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

Catalytic Reduction and Exhaust Gas Recirculation Systems Optimization A patented EGR-SCR approach was shown to readily meet the 2010 EPA requirments for NOx and PM emisisons...

231

Selectlive Catalytic Reducution of NOx wilth Diesel-Based Fuels...  

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

of NO by Hydrocarbons Bifunctional Catalysts for the Selective Catalytic Reduction of NO by Hydrocarbons Progress on Acidic Zirconia Mixed Oxides for Efficient NH3-SCR Catalysis...

232

Printing 3D Catalytic Devices | The Ames Laboratory  

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

Printing 3D Catalytic Devices Ames Laboratory scientist Igor Slowing discusses using 3D printers to create new materials, including catalysts...

233

Catalytic Conversion of Biomass-derived Feedstock (HMF) into...  

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

Industrial Technologies Industrial Technologies Biomass and Biofuels Biomass and Biofuels Find More Like This Return to Search Catalytic Conversion of Biomass-derived Feedstock...

234

Catalytic distillation for the synthesis of tertiary butyl alcohol.  

E-Print Network [OSTI]

??Catalytic Distillation for the synthesis of tertiary butyl alcohol (TBA) is investigated in this thesis. The solvent, ethylene glycol, is proposed as a means of… (more)

Safinski, Tomasz

2005-01-01T23:59:59.000Z

235

Single Supported Atoms Participate in Catalytic Processes | ornl...  

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

Functional Materials for Energy Single Supported Atoms Participate in Catalytic Processes December 04, 2014 Pathways for NO oxidation on single Pt atoms supported on the (010)...

236

3D Printing of nanostructured catalytic materials | The Ames...  

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

3D Printing of nanostructured catalytic materials Over the last couple of decades, scientists have been able to develop a tremendous control over the synthesis and properties of...

237

The Effects of Trace Contaminants on Catalytic Processing of...  

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

Processing of Biomass-Derived Feedstocks . Abstract: Trace components in biomass feedstocks are potential catalyst poisons when catalytically processing these materials to...

238

Catalytic Upgrading of Sugars to Hydrocarbons Technology Pathway...  

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

the catalytic conversion of solubilized carbohydrate streams to hydrocarbon biofuels, utilizing data from recent efforts within the National Advanced Biofuels Consortium...

239

Passive Catalytic Approach to Low Temperature NOx Emission Abatement  

Broader source: Energy.gov [DOE]

Numerically evaluated and optimized proposed state-of-the-art passive catalytic technology designed to reduce NOx released during vehicle cold start portion of the FTP-75 cycle

240

E-Print Network 3.0 - applications crack growth Sample Search...  

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

that the critical crack-tip opening angle (CTOA) value measured on the specimen... fracture changes a Mode-I type of crack growth to a mixed-mode IIII type of crack growth. It...

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


241

A nanomechanical investigation of the crack tip process zone of marble  

E-Print Network [OSTI]

This study explores the interaction between crack initiation and nanomechanical properties in the crack tip process zone (zone of microcracking at the tip of a propagating crack) of a brittle geomaterial. Samples of Carrara ...

Brooks, Zenzile (Zenzile Z.)

2010-01-01T23:59:59.000Z

242

Fatigue of polycrystalline silicon for MEMS applications: Crack growth and stability under resonant loading conditions  

E-Print Network [OSTI]

S.B. , 1999. Subcritical crack growth in silicon MEMS. J.appearance of subcritical crack growth in the absence ofbe mistaken for subcritical fatigue-crack growth when the

Muhlstein, C.L.; Howe, R.T.; Ritchie, R.O.

2001-01-01T23:59:59.000Z

243

Propagating solitary waves along a rapidly moving crack front  

Science Journals Connector (OSTI)

... Much recent research has focused on crack front coherence and roughening. Simplified models (mode III) of fracture as well as more general models of ... the cumulative effect of numerous asperities would be to cause a crack front to continually roughen. We point out that despite this possibility of increasing roughness, the propagating nature of ...

Eran Sharon; Gil Cohen; Jay Fineberg

2001-03-01T23:59:59.000Z

244

Fracture mechanics analysis of slow crack growth in polyethylene  

E-Print Network [OSTI]

Slow crack growth in polyethylene is often the limiting factor in long-term service of plastic pipe or other structural applications. A new test method and analysis method was developed to study slow crack growth in polyethylene. Two high density...

Self, Robert Alan

1997-01-01T23:59:59.000Z

245

The Influence of Crystallographic Orientation on Crack Tip Displacements of  

E-Print Network [OSTI]

consists of 212 randomly shaped, sized and oriented grains, loaded monotonically in uniaxial tension to a maximum load of 0.9Rp0.2 (240 MPa). The influence that a random grain structure imposes on a Stage I crack will preferably follow the slip plane where the crack tip opening displacement is highest, we show

Cizelj, Leon

246

Prediction of pure water stress corrosion cracking (PWSCC) in nickel base alloys using crack growth rate models  

SciTech Connect (OSTI)

The Ford/Andresen slip dissolution SCC model, originally developed for stainless steel components in BWR environments, has been applied to Alloy 600 and Alloy X-750 tested in deaerated pure water chemistry. A method is described whereby the crack growth rates measured in compact tension specimens can be used to estimate crack growth in a component. Good agreement was found between model prediction and measured SCC in X-750 threaded fasteners over a wide range of temperatures, stresses, and material condition. Most data support the basic assumption of this model that cracks initiate early in life. The evidence supporting a particular SCC mechanism is mixed. Electrochemical repassivation data and estimates of oxide fracture strain indicate that the slip dissolution model can account for the observed crack growth rates, provided primary rather than secondary creep rates are used. However, approximately 100 cross-sectional TEM foils of SCC cracks including crack tips reveal no evidence of enhanced plasticity or unique dislocation patterns at the crack tip or along the crack to support a classic slip dissolution mechanism. No voids, hydrides, or microcracks are found in the vicinity of the crack tips creating doubt about classic hydrogen related mechanisms. The bulk oxide films exhibit a surface oxide which is often different than the oxides found within a crack. Although bulk chromium concentration affects the rate of SCC, analytical data indicates the mechanism does not result from chromium depletion at the grain boundaries. The overall findings support a corrosion/dissolution mechanism but not one necessarily related to slip at the crack tip.

Thompson, C.D.; Krasodomski, H.T.; Lewis, N.; Makar, G.L.

1995-02-22T23:59:59.000Z

247

Catalytic bromine recovery from HBr waste  

SciTech Connect (OSTI)

Waste HBr is formed during the bromination of many organic molecules, such as flame retardants, pharmaceuticals, and agricultural chemicals. For over 50 years attempts to recover the bromine from waste HBr by catalytic oxidation have been unsuccessful due to low catalyst activity and stability. The discovery of a new high-activity catalysts with excellent long-term stability and life capable of high HBr conversion below 300{degrees}C has made catalytic oxidation of waste HBr commercially feasible. The oxidation of anhydrous HBr using oxygen is highly exothermic, giving an adiabatic temperature rise of 2000{degrees}C. Use of 48 wt% HBr in the oxidation reduces the adiabatic temperature rise to only 300{degrees}C. A multitubular heat exchanger type of reactor can then be used to manage the heat. A 5,000 kg/yr pilot plant was built to verify the performance of the catalyst, the suitability of the reactor materials of construction, and the multibular reactor concept. The pilot unit has a single full-scale reactor tube 4 m long and 2.54 cm in diameter with a hot oil jacket for heat management. Excellent catalyst stability was observed during a 600 h catalyst-life test. HBr conversion of 99% was maintained throughout the run, and over 360 kg of bromine was produced. The temperature at a localized hot spot near the reactor inlet was only 15-20{degrees}C above the reactor inlet temperature, indicating efficient heat management.

Schubert, P.F.; Beatty, R.D.; Mahajan, S. [Catalytica Inc., Mountain View, CA (United States)

1993-12-31T23:59:59.000Z

248

Catalytic reactor for low-Btu fuels  

DOE Patents [OSTI]

An improved catalytic reactor includes a housing having a plate positioned therein defining a first zone and a second zone, and a plurality of conduits fabricated from a heat conducting material and adapted for conducting a fluid therethrough. The conduits are positioned within the housing such that the conduit exterior surfaces and the housing interior surface within the second zone define a first flow path while the conduit interior surfaces define a second flow path through the second zone and not in fluid communication with the first flow path. The conduit exits define a second flow path exit, the conduit exits and the first flow path exit being proximately located and interspersed. The conduits define at least one expanded section that contacts adjacent conduits thereby spacing the conduits within the second zone and forming first flow path exit flow orifices having an aggregate exit area greater than a defined percent of the housing exit plane area. Lastly, at least a portion of the first flow path defines a catalytically active surface.

Smith, Lance (North Haven, CT); Etemad, Shahrokh (Trumbull, CT); Karim, Hasan (Simpsonville, SC); Pfefferle, William C. (Madison, CT)

2009-04-21T23:59:59.000Z

249

E-Print Network 3.0 - assisted cracking resistance Sample Search...  

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

crack... and the time-dependent, environmentally-assisted, crack initiation and subcritical growth in the oxide layer... of exploring these prin- ciples is seen in Figure 5....

250

The significance of crack-resistance curves to the mixed-mode fracture toughness of human cortical bone  

E-Print Network [OSTI]

in the presence of subcritical crack growth. It involvesgrowth (not crack initiation). As a result, stable (subcritical)

Zimmermann, Elizabeth A.

2010-01-01T23:59:59.000Z

251

Insights into Stress Corrosion Cracking Mechanisms from High-Resolution Measurements of Crack-Tip Structures and Compositions  

SciTech Connect (OSTI)

The fundamental basis for mechanistic understanding and modeling of SCC remains in question for many systems. Specific mechanisms controlling SCC can vary with changes in alloy characteristics, applied/residual stress or environmental conditions. The local crack electrochemistry, crack-tip mechanics and material metallurgy are the main factors controlling crack growth. These localized properties are difficult or impossible to measure in active cracks. Nevertheless, it is essential to quantitatively interrogate these crack-tip conditions if mechanistic understanding is to be obtained. A major recent advance has been the ability to investigate SCC cracks and crack tips using high-resolution ATEM techniques. ATEM enables the characterization of SCC cracks including trapped tip solution chemistries, corrosion product/film compositions and structures, and elemental composition gradients and defect microstructures along the crack walls and at the crack tip. A wide variety of methods for imaging and analyses at resolutions down to the atomic level can be used to examine the crack and corrosion film characteristics. Surface films and reaction layers have been examined by cross-sectional TEM techniques, but little work had been conducted on environmentally induced internal cracks until that of Lewis and co-workers [1-3] and the current authors [4-17]. This capability combined with modern ATEM techniques has enabled exciting new insights into corrosion processes occurring at buried interfaces and is being used to identify mechanisms controlling IGSCC in boiling water reactor (BWR) and pressurized water reactor (PWR) components. The objective of this paper is to summarize certain results focused on IGSCC of Fe- base and Ni-base stainless alloys in high-temperature water environments. Representative crack-tip examples will be shown to illustrate specific aspects that are characteristic of SCC in the material/environment combinations. Differences and similarities in crack-tip structures- chemistries will be highlighted comparing Fe-base 316/304SS to Ni-base alloy 600/182 and for tests in oxidizing versus hydrogenated water environments.

Bruemmer, Stephen M.; Thomas, Larry E.

2010-04-05T23:59:59.000Z

252

Catalytic Membrane Reactor for Extraction of Hydrogen from Bioethanol Reforming  

E-Print Network [OSTI]

-gas-shift catalytic membrane reactor, and (2) a multi-layer design for bioethanol reforming. A two-dimensional model is developed to describe reaction and diffusion in the catalytic membrane coupled with plug-flow equations in the retentate and permeate volumes using...

Kuncharam, Bhanu Vardhan

2013-11-26T23:59:59.000Z

253

Factors Affecting the Hydrogen Environment Assisted Cracking Resistance of an Al-Zn-Mg-(Cu) Alloy  

SciTech Connect (OSTI)

It is well established that Al-Zn-Mg-(Cu) aluminum alloys are susceptible to hydrogen environment assisted cracking (HEAC) when exposed to aqueous environments. In Al-Zn-Mg-Cu alloys, overaged tempers are commonly used to increase HEAC resistance at the expense of strength. Overaging has little benefit in low copper alloys. However, the mechanism or mechanisms by which overaging imparts HEAC resistance is poorly understood. The present research investigated hydrogen uptake, diffusion, and crack growth rate in 90% relative humidity (RH) air for both a commercial copper bearing Al-Zn-Mg-Cu alloy (AA 7050) and a low copper variant of this alloy in order to better understand the factors which affect HEAC resistance. Experimental methods used to evaluate hydrogen concentrations local to a surface and near a crack tip include nuclear reaction analysis (NRA), focused ion beam, secondary ion mass spectroscopy (FIB/SIMS) and thermal desorption spectroscopy (TDS). When freshly bared coupons of AA 7050 are exposed to 90 C, 90% RH air, hydrogen ingress follows inverse-logarithmic-type kinetics and is equivalent for underaged (HEAC susceptible) and overaged (HEAC resistant) tempers. However, when the native oxide is allowed to form (24 hrs in 25 C, 40% RH lab air) prior to exposure to 90 C, 90% RH air, underaged alloy shows significantly greater hydrogen ingress than the overaged alloy. Humid air is a very aggressive environment producing local ({approx}1{micro}m) hydrogen concentrations in excess of 10,000 wt. ppm at 90 C. In the copper bearing alloy, overaging also effects the apparent diffusivity of hydrogen. As AA 7050 is aged from underaged {yields} peak aged {yields} overaged, the activation energy for hydrogen diffusion increases and the apparent diffusivity for hydrogen decreases, In the low copper alloy, overaging has little effect on hydrogen diffusion. Comparison of the apparent activation energies for hydrogen diffusion and for K independent (stage II) crack growth rate in 90% RH air between 25 and 90 C indicates that hydrogen transport kinetics are responsible for the decreased crack growth rate of overaged AA 7050 relative to the peak aged temper.

G.A. Young; J.R. Scully

2001-09-12T23:59:59.000Z

254

Contact structure for use in catalytic distillation  

DOE Patents [OSTI]

A method is described for conducting catalytic chemical reactions and fractionation of the reaction mixture comprising feeding reactants into a distillation column reactor, contracting said reactant in liquid phase with a fixed bed catalyst in the form of a contact catalyst structure consisting of closed porous containers containing the catalyst for the reaction and a clip means to hold and support said containers, which are disposed above, i.e., on the distillation trays in the tower. The trays have weir means to provide a liquid level on the trays to substantially cover the containers. In other words, the trays function in their ordinary manner with the addition thereto of the catalyst. The reaction mixture is concurrently fractionated in the column. 7 figs.

Jones, E.M. Jr.

1984-03-27T23:59:59.000Z

255

Contact structure for use in catalytic distillation  

DOE Patents [OSTI]

A method and apparatus are disclosed for conducting catalytic chemical reactions and fractionation of the reaction mixture, comprising and feeding reactants into a distillation column reactor contracting said reactant in a liquid phase with a fixed bed catalyst in the form of a contact catalyst structure, consisting of closed porous containers containing the catalyst for the reaction and a clip means to hold and support said containers, which are disposed above, i.e., on the distillation trays in the tower. The trays have weir means to provide a liquid level on the trays to substantially cover the containers. In other words, the trays function in their ordinary manner with the addition thereto of the catalyst. The reaction mixture is concurrently fractionated in the column. 7 figs.

Jones, E.M. Jr.

1985-08-20T23:59:59.000Z

256

Contact structure for use in catalytic distillation  

DOE Patents [OSTI]

A method for conducting catalytic chemical reactions and fractionation of the reaction mixture comprising feeding reactants into a distillation column reactor contracting said reactant in liquid phase with a fixed bed catalyst in the form of a contact catalyst structure consisting of closed porous containers containing the catatlyst for the reaction and a clip means to hold and support said containers, which are disposed above, i.e., on the distillation trays in the tower. The trays have weir means to provide a liquid level on the trays to substantially cover the containers. In other words, the trays function in their ordinary manner with the addition thereto of the catalyst. The reaction mixture is concurrently fractionated in the column.

Jones, Jr., Edward M. (Friendswood, TX)

1984-01-01T23:59:59.000Z

257

Contact structure for use in catalytic distillation  

DOE Patents [OSTI]

A method and apparatus for conducting catalytic chemical reactions and fractionation of the reaction mixture, comprising and feeding reactants into a distillation column reactor contracting said reactant in a liquid phase with a fixed bed catalyst in the form of a contact catalyst structure, consisting of closed porous containers containing the catalyst for the reaction and a clip means to hold and support said containers, which are disposed above, i.e., on the distillation trays in the tower. The trays have weir means to provide a liquid level on the trays to substantially cover the containers. In other words, the trays function in their ordinary manner with the addition thereto of the catalyst. The reaction mixture is concurrently fractionated in the column.

Jones, Jr., Edward M. (Friendswood, TX)

1985-01-01T23:59:59.000Z

258

Author's personal copy Effect of fluid salinity on subcritical crack propagation in calcite  

E-Print Network [OSTI]

Author's personal copy Effect of fluid salinity on subcritical crack propagation in calcite Fatma Accepted 22 October 2012 Available online 31 October 2012 Keywords: Subcritical crack growth Calcite Salt Damage The slow propagation of cracks, also called subcritical crack growth, is a mechanism of fracturing

259

A three-dimensional validation of crack curvature in muscovite mica  

SciTech Connect (OSTI)

Experimental and computational efforts focused on characterizing crack tip curvature in muscovite mica. Wedge-driven cracks were propagated under monochromatic light. Micrographs verified the subtle curvature of the crack front near the free surface. A cohesive approach was employed to model mixed-mode fracture in a three-dimensional framework. Finite element calculations captured the crack curvature observed in experiment.

J. C. Hill; J. W. Foulk III; P. A. Klein; E. P. Chen

2001-01-07T23:59:59.000Z

260

EFFECT OF VISCOUS GRAIN BRIDGING ON CYCLIC FATIGUE-CRACK GROWTH IN MONOLITHIC CERAMICS  

E-Print Network [OSTI]

, toughness, creep, and subcritical crack growth [1± 10]. Under quasi-static loading, subcritical crack growthEFFECT OF VISCOUS GRAIN BRIDGING ON CYCLIC FATIGUE-CRACK GROWTH IN MONOLITHIC CERAMICS AT ELEVATED allow for consistent crack-growth monitoring in these materials at high temperatures, and even

Ritchie, Robert

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


261

Cyclic fatigue-crack propagation in sapphire in air and simulated physiological environments  

E-Print Network [OSTI]

for the first time in sapphire for both modes of subcritical cracking. It was found that growth rates were on the subcritical crack-growth prop- erties of sapphire. In general, crack growth in many polycrystalline ce- ramics loads. This article describes an investigation of subcritical crack growth in sapphire under both mon

Ritchie, Robert

262

Environmentally Assisted Cracking of Ni-Base Alloys [Corrosion and  

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

LWRs > Environmentally Assisted LWRs > Environmentally Assisted Cracking of Ni-Base Alloys Capabilities Materials Testing Environmentally Assisted Cracking (EAC) of Reactor Materials Corrosion Performance/Metal Dusting Overview Light Water Reactors Fatigue Testing of Carbon Steels and Low-Alloy Steels Environmentally Assisted Cracking of Ni-Base Alloys Irradiation-Induced Stress Corrosion Cracking of Austenitic Stainless Steels Steam Generator Tube Integrity Program Air Oxidation Kinetics for Zr-based Alloys Fossil Energy Fusion Energy Metal Dusting Publications List Irradiated Materials Steam Generator Tube Integrity Other Facilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Corrosion and Mechanics of Materials Light Water Reactors

263

Irradiation-Induced Stress Corrosion Cracking of Austenitic Stainless  

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

Environmentally Assisted Environmentally Assisted Cracking of Ni-Base Alloys Capabilities Materials Testing Environmentally Assisted Cracking (EAC) of Reactor Materials Corrosion Performance/Metal Dusting Overview Light Water Reactors Fatigue Testing of Carbon Steels and Low-Alloy Steels Environmentally Assisted Cracking of Ni-Base Alloys Irradiation-Induced Stress Corrosion Cracking of Austenitic Stainless Steels Steam Generator Tube Integrity Program Air Oxidation Kinetics for Zr-based Alloys Fossil Energy Fusion Energy Metal Dusting Publications List Irradiated Materials Steam Generator Tube Integrity Other Facilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Corrosion and Mechanics of Materials Light Water Reactors Bookmark and Share

264

Automated crack control analysis for concrete pavement construction  

E-Print Network [OSTI]

The focus of this research is on the control of random cracking in concrete paving by using sawcut notch locations in the early stages of construction. This is a major concern in concrete pavement construction. This research also addresses a...

Jang, Se Hoon

2005-11-01T23:59:59.000Z

265

Modeling of crack initiation, propagation and coalescence in rocks  

E-Print Network [OSTI]

Natural or artificial fracturing of rock plays a very important role in geologic processes and for engineered structures in and on rock. Fracturing is associated with crack initiation, propagation and coalescence, which ...

Gonçalves da Silva, Bruno Miguel

2009-01-01T23:59:59.000Z

266

Delayed hydride cracking behavior for ZIRCALOY-2 tubing  

Science Journals Connector (OSTI)

The delayed hydride cracking (DHC) behavior for ZIRCALOY-2 tubing was characterized at temperatures ranging from 93 °C to 288 °C. Testing was performed on the three types of pressure tubes that were used in th...

F. H. Huang; W. J. Mills

1991-09-01T23:59:59.000Z

267

Field Examples of Axial Cracked Bearings in Wind Turbine Gearboxes...  

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

Field Examples of Axial Cracked Bearings in Wind Turbine Gearboxes Presented by Paul John Baker of FrontierPro Services at the Wind Turbine Tribology Seminar 2014. 141030 Axial...

268

SAFT Imaging of Transverse Cracks in Austenitic and Dissimilar Welds  

Science Journals Connector (OSTI)

Up to now there is no sufficient technique to detect transverse cracks in austenitic and dissimilar welds which recently are of increasing interest in the integrity surveillance of nuclear power plants as well as...

Christian Höhne; Sanjeevareddy Kolkoori…

2013-03-01T23:59:59.000Z

269

Failure analysis of a cracked diesel engine clutch spring plate  

Science Journals Connector (OSTI)

A diesel engine clutch spring plate used in a truck cracked when testing was being performed. The crack initiated from the middle of the thickness direction of the plate and propagated toward the front and the back of the plate. Fractographic studies indicate that brittle intergranular fracture was the dominant failure mechanism. Many parallel band structures were observed along the radial direction of the plate in the intergranular fracture region; a high density of secondary cracks and fine intergranular particles were found in this banded region. Metallurgical examinations indicated segregation of elongated MnS inclusions and the presence of granular vanadium carbides along the radial direction of the plate, at the location of the crack origin. Segregation of the elongated MnS inclusions leads to a reduction in toughness, and the combined segregation of inclusions and impurity elements at grain boundaries result in weakening of the boundaries. These conditions led to the intergranular brittle fracture of the clutch spring plate.

Zhiwei Yu; Xiaolei Xu

2008-01-01T23:59:59.000Z

270

Sequential tasks performed by catalytic pumps for colloidal crystallization  

E-Print Network [OSTI]

Gold-platinum catalytic pumps immersed in a chemical fuel are used to manipulate silica colloids. The manipulation relies on the electric field and the fluid flow generated by the pump. Catalytic pumps perform various tasks, such as the repulsion of colloids, the attraction of colloids, and the guided crystallization of colloids. We demonstrate that catalytic pumps can execute these tasks sequentially over time. Switching from one task to the next is related to the local change of the proton concentration, which modifies the colloid zeta potential and consequently the electric force acting on the colloids.

Ali Afshar Farniya; Maria J. Esplandiu; Adrian Bachtold

2014-10-20T23:59:59.000Z

271

J-integral values for cracks in conventional fatigue specimens  

SciTech Connect (OSTI)

Comprehensive S-N fatigue data has been developed worldwide using conventional low-cycle fatigue tests. Such tests use smooth unnotched specimens subjected to controlled axial deflection or strain ranges. The tests must be run in the plastic regime in order to achieve the required cycles-to-failure. Recent developments have highlighted the need to understand and interpret the significance of the resulting strain range vs. cycles to failure data in terms of crack initiation and propagation. Since conventional fatigue tests are conducted in the plastic regime, linear elastic fracture mechanics cannot be used to accurately quantify crack growth in such tests. Elastic-plastic J-integral theory, however, has been shown to provide excellent correlations of crack growth in the elastic, elastic-plastic and grossly-plastic regimes for a wide range of geometric and loading conditions. The authors are applying this theory to the low-cycle fatigue specimen crack behavior. As cracks progress in conventional fatigue specimens, bending becomes significant. Since fatigue testing machines are quite stiff relative to the small fatigue specimens, the ends of the specimen are constrained to remain parallel, and this reduces bending in the cracked cross-section. Three-dimensional finite element elastic-plastic analyses are required to include these constraints in the J-integral solutions.

O`Donnell, T.P.; O`Donnell, W.J. [O`Donnell Consulting Engineers, Pittsburgh, PA (United States)

1996-12-01T23:59:59.000Z

272

Research on mechanisms of stress corrosion cracking in Zircaloy  

SciTech Connect (OSTI)

The results of internal gas pressurization tests, primarily at 320/sup 0/C, on cladding tubes from two suppliers, Supplier A and Supplier B, are presented. The two lots show a substantial difference in iodine SCC susceptibility so a test matrix is used to resolve the relative contributions of surface condition, residual stress, and texture. Additional tests with constant deflection split-ring specimens and with unstressed cladding segments are used to understand crack initiation and the early crack growth stages of SCC. The difference in SCC susceptibility is due to crystallographic texture. Other variables such as surface finish, stress relief temperature, and residual stress have little or no effect. Mechanical properties, crack initiation, and crack propagation all depend on texture. Both initiation and propagation features are analyzed by scanning electron microscopy. A mechanism for crack initiation consistent with most observations in this study and with the work of other investigators is proposed. At 320/sup 0/C, lifetime is crack initiation limited while several tests at 390/sup 0/C indicate that lifetime is less initiation limited at higher temperature. 31 figures, 9 tables.

Knorr, D.B.; Pelloux, R.M.

1981-06-01T23:59:59.000Z

273

Thermal treatment  

Science Journals Connector (OSTI)

Thermal treatment can be regarded as either a pre-treatment of waste prior to final disposal, or as a means of valorising waste by recovering energy. It includes both the burning of mixed MSW in municipal inciner...

Dr. P. White; Dr. M. Franke; P. Hindle

1995-01-01T23:59:59.000Z

274

Thermal Processes  

Broader source: Energy.gov [DOE]

Some thermal processes use the energy in various resources, such as natural gas, coal, or biomass, to release hydrogen, which is part of their molecular structure. In other processes, heat, in...

275

ffe1098 FFE March 7, 2007 21:55 Crack tip displacements of microstructurally small cracks in 316L steel  

E-Print Network [OSTI]

steel and their dependence on crystallographic orientations of grains I. SIMONOVSKI1 , KARL orientations on a short Stage I surface crack in a 316L stainless steel. The analysis is based on a plane

Cizelj, Leon

276

CATALYTIC MICROWAVE PYROLYSIS OF BIOMASS FOR RENEWABLE PHENOLS AND FUELS .  

E-Print Network [OSTI]

??Bio-oil is an unstable intermediate and needs to be upgraded before its use. This study focused on improving the selectivity of bio-oilby catalytic pyrolysis of… (more)

[No author

2013-01-01T23:59:59.000Z

277

Catalyst Cartography: 3D Super-Resolution Mapping of Catalytic...  

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

Catalyst Cartography: 3D Super-Resolution Mapping of Catalytic Activity Thanks to a groundbreaking new method, scientists have created the first 3D super-resolution maps of...

278

In situ XAS Characterization of Catalytic Nano-Materials with...  

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

XAS Characterization of Catalytic Nano-Materials with Applications to Fuel Cells and Batteries Friday, July 12, 2013 - 11:00am SLAC, Conference Room 137-322 Presented by Qingying...

279

Strengthening, Crack Arrest And Multiple Cracking In Brittle Materials Using Residual Stresses.  

DOE Patents [OSTI]

Embodiments include a method for forming a glass which displays visible cracking prior to failure when subjected to predetermined stress level that is greater than a predetermined minimum stress level and less than a failure stress level. The method includes determining a critical flaw size in the glass and introducing a residual stress profile to the glass so that a plurality of visible cracks are formed prior to failure when the glass is subjected to a stress that is greater than the minimum stress level and lower than the critical stress. One method for forming the residual stress profile includes performing a first ion exchange so that a first plurality of ions of a first element in the glass are exchanged with a second plurality of ions of a second element that have a larger volume than the first ions. A second ion exchange is also performed so that a plurality of the second ions in the glass are exchanged back to ions of the first element.

Green, David J. (State College, PA); Sglavo, Vincenzo M. (Roncegno, IT); Tandon, Rajan (Fremont, CA)

2003-02-11T23:59:59.000Z

280

Catalytic Reactor For Oxidizing Mercury Vapor  

DOE Patents [OSTI]

A catalytic reactor (10) for oxidizing elemental mercury contained in flue gas is provided. The catalyst reactor (10) comprises within a flue gas conduit a perforated corona discharge plate (30a, b) having a plurality of through openings (33) and a plurality of projecting corona discharge electrodes (31); a perforated electrode plate (40a, b, c) having a plurality of through openings (43) axially aligned with the through openings (33) of the perforated corona discharge plate (30a, b) displaced from and opposing the tips of the corona discharge electrodes (31); and a catalyst member (60a, b, c, d) overlaying that face of the perforated electrode plate (40a, b, c) opposing the tips of the corona discharge electrodes (31). A uniformly distributed corona discharge plasma (1000) is intermittently generated between the plurality of corona discharge electrode tips (31) and the catalyst member (60a, b, c, d) when a stream of flue gas is passed through the conduit. During those periods when corona discharge (1000) is not being generated, the catalyst molecules of the catalyst member (60a, b, c, d) adsorb mercury vapor contained in the passing flue gas. During those periods when corona discharge (1000) is being generated, ions and active radicals contained in the generated corona discharge plasma (1000) desorb the mercury from the catalyst molecules of the catalyst member (60a, b, c, d), oxidizing the mercury in virtually simultaneous manner. The desorption process regenerates and activates the catalyst member molecules.

Helfritch, Dennis J. (Baltimore, MD)

1998-07-28T23:59:59.000Z

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


281

Catalytic pyrolysis using UZM-39 aluminosilicate zeolite  

SciTech Connect (OSTI)

A new family of coherently grown composites of TUN and IMF zeotypes has been synthesized and shown to be effective catalysts for catalytic pyrolysis of biomass. These zeolites are represented by the empirical formula. Na.sub.nM.sub.m.sup.n+R.sub.rQ.sub.qAl.sub.1-xE.sub.xSi.sub.yO.s- ub.z where M represents zinc or a metal or metals from Group 1, Group 2, Group 3 or the lanthanide series of the periodic table, R is an A,.OMEGA.-dihalosubstituted paraffin such as 1,4-dibromobutane, Q is a neutral amine containing 5 or fewer carbon atoms such as 1-methylpyrrolidine and E is a framework element such as gallium. The process involves contacting a carbonaceous biomass feedstock with UZM-39 at pyrolysis conditions to produce pyrolysis gases comprising hydrocarbons. The catalyst catalyzes a deoxygenation reaction converting oxygenated hydrocarbons into hydrocarbons and removing the oxygen as carbon oxides and water. A portion of the pyrolysis gases is condensed to produce low oxygen biomass-derived pyrolysis oil.

Nicholas, Christopher P; Boldingh, Edwin P

2014-10-07T23:59:59.000Z

282

Microchannel Reactor System for Catalytic Hydrogenation  

SciTech Connect (OSTI)

We successfully demonstrated a novel process intensification concept enabled by the development of microchannel reactors, for energy efficient catalytic hydrogenation reactions at moderate temperature, and pressure, and low solvent levels. We designed, fabricated, evaluated, and optimized a laboratory-scale microchannel reactor system for hydrogenation of onitroanisole and a proprietary BMS molecule. In the second phase of the program, as a prelude to full-scale commercialization, we designed and developed a fully-automated skid-mounted multichannel microreactor pilot plant system for multiphase reactions. The system is capable of processing 1 – 10 kg/h of liquid substrate, and an industrially relevant immiscible liquid-liquid was successfully demonstrated on the system. Our microreactor-based pilot plant is one-of-akind. We anticipate that this process intensification concept, if successfully demonstrated, will provide a paradigm-changing basis for replacing existing energy inefficient, cost ineffective, environmentally detrimental slurry semi-batch reactor-based manufacturing practiced in the pharmaceutical and fine chemicals industries.

Adeniyi Lawal; Woo Lee; Ron Besser; Donald Kientzler; Luke Achenie

2010-12-22T23:59:59.000Z

283

Catalytic pyrolysis using UZM-39 aluminosilicate zeolite  

DOE Patents [OSTI]

A new family of coherently grown composites of TUN and IMF zeotypes has been synthesized and show to be effective catalysts for catalytic pyrolysis of biomass. These zeolites are represented by the empirical formula. Na.sub.nM.sub.m.sup.n+R.sub.rQ.sub.qAl.sub1-xE.sub.xSi.sub.yO.s- ub.z where M represents zinc or a metal or metals from Group 1, Group 2, Group 3 or the lanthanide series of the periodic table, R is an A,.OMEGA.-dihalosubstituted paraffin such as 1,4-dibromobutane, Q is a neutral amine containing 5 or fewer carbon atoms such as 1-methylpyrrolidine and E is a framework element such as gallium. The process involves contacting a carbonaceous biomass feedstock with UZM-39 at pyrolysis conditions to produce pyrolysis gases comprising hydrocarbons. The catalyst catalyzes a deoxygenation reaction converting oxygenated hyrdocarbons into hydrocarbons removing the oxygen as carbon oxides and water. A portion of the pyrolysis gases is condensed to produce low oxygen biomass-derived pyrolysis oil.

Nicholas, Christpher P; Boldingh, Edwin P

2013-12-17T23:59:59.000Z

284

Matrix fatigue cracking mechanisms of alpha(2) TMC for hypersonic applications  

SciTech Connect (OSTI)

The objective of this work was to understand matrix cracking mechanisms in a unidirectional alpha[sub 2] TMC in possible hypersonic applications. A (0)[sub 8] SCS-6/Ti-24Al-11Nb (at. percent) TMC was first subjected to a variety of simple isothermal and nonisothermal fatigue cycles to evaluate the damage mechanisms in simple conditions. A modified ascent mission cycle test was then performed to evaluate the combined effects of loading modes. This cycle mixes mechanical cycling at 150 and 483 C, sustained loads, and a slow thermal cycle to 815 C. At low cyclic stresses and strains more common in hypersonic applications, environment-assisted surface cracking limited fatigue resistance. This damage mechanism was most acute for out-of-phase nonisothermal cycles having extended cycle periods and the ascent mission cycle. A simple linear fraction damage model was employed to help understand this damage mechanism. Time-dependent environmental damage was found to strongly influence out-of-phase and mission life, with mechanical cycling damage due to the combination of external loading and CTE mismatch stresses playing a smaller role. The mechanical cycling and sustained loads in the mission cycle also had a smaller role.

Gabb, T.P.; Gayda, J.

1994-02-01T23:59:59.000Z

285

Matrix fatigue cracking in {alpha}{sub 2} titanium matrix composites for hypersonic applications  

SciTech Connect (OSTI)

The objective of this work was to understand matrix cracking mechanisms in a unidirectional {alpha}{sub 2} titanium matrix composite (TMC) in possible hypersonic applications. A [0]{sub 8} SCS-6/Ti-24Al-11Nb (atomic %) TMC was first subjected to a variety of simple isothermal and nonisothermal fatigue cycles to evaluate the damage mechanisms in simple conditions. A modified ascent mission cycle test was then performed to evaluate the combined effects of loading modes. This cycle mixes mechanical cycling at 150 and 483 C, sustained loads, and a slow thermal cycle to 815 C. At low cyclic stresses and strains more common in hypersonic applications, environment-assisted surface cracking limited fatigue resistance. This damage mechanism was most acute for out-of-phase nonisothermal cycles having extended cycle periods and the ascent mission cycle. A simple linear fraction damage model was employed to help understand this damage mechanism. Time-dependent environmental damage was found to strongly influence out-of-phase and mission life, with mechanical cycling damage due to the combination of external loading and CTE mismatch stresses playing a smaller role. The mechanical cycling and sustained loads in the mission cycle also had a smaller role.

Gabb, T.P.; Gayda, J. [NASA Lewis Research Center, Cleveland, OH (United States)

1996-12-31T23:59:59.000Z

286

Catalytic Transformation of Waste Carbon Dioxide into Valuable Products  

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

Catalytic Transformation of Waste Catalytic Transformation of Waste Carbon Dioxide into Valuable Products Background Many industrial processes contribute large amounts of carbon dioxide (CO 2 ) to the earth's atmosphere. In an effort to reduce the amount of CO 2 released to the atmosphere, the U.S. Department of Energy (DOE) is funding efforts to develop CO 2 capture and storage technologies. In addition to permanent storage of CO 2 in underground reservoirs, some

287

Northwestern University Facility for Clean Catalytic Process Research  

SciTech Connect (OSTI)

Northwestern University with DOE support created a Facility for Clean Catalytic Process Research. This facility is designed to further strengthen our already strong catalysis research capabilities and thus to address these National challenges. Thus, state-of-the art instrumentation and experimentation facility was commissioned to add far greater breadth, depth, and throughput to our ability to invent, test, and understand catalysts and catalytic processes, hence to improve them via knowledge-based design and evaluation approaches.

Marks, Tobin Jay [Northwestern University

2013-05-08T23:59:59.000Z

288

Aluminosilicates as controlled molecular environments for selective photochemical and catalytic reactions  

SciTech Connect (OSTI)

This dissertation concerns research that involves photochemical, catalytic and spectroscopic studies of clays, pillared clays and zeolites. Incorporation of uranyl ions into hectorite, montmorillonite, bentonite and vermiculite clays was monitored by XRD and luminescence methods. Excitation and emission characteristics were studied in order to understand the behavior of uranyl ions in clays after various thermal treatments. Luminescence lifetime measurements elucidated the number of uranyl sites. Uranyl-exchanged clays were found to absorb light at lower energies (445-455nm) than analogous uranyl-exchanged zeolites (425nm). Each uranyl-exchanged clay was tested as a catalyst for the photoassisted oxidation of isopropyl alcohol. Energy transfer (ET) between uranyl and Eu(III) ions in different zeolite framework systems was examined. The efficiency of ET (eta/sub t/) was found to be affected by the type of framework present. Pillared bentonites were examined in the hydrocracking of decane. A catalytically and spectroscopically active dopant ion, Cr(III), was introduced into the clays in both pillared and unpillared forms depending upon synthetic conditions. EPR and DRS were employed to monitor the environment of Cr(III) for determination of its location - whether in the micropore structure or associated with alumina pillars. Catalytic behavior based upon this variability of location was examined. Incorporation of Cr(III) ions into an alumina pillar was found to increase the stability and activity with respect to an alumina PILC catalyst. The results of these studies suggest that selective, efficient catalysts can be designed around inorganic ions in aluminosilicate supports.

Carrado, K.A.

1986-01-01T23:59:59.000Z

289

Statistical simulation of small fatigue crack nucleation and coalescence in a lamellar TiAl alloy  

SciTech Connect (OSTI)

This article examines the possibility of fatigue failure as the result of fatigue crack nucleation and coalescence at stress ranges below the fatigue limit and the large crack threshold where fatigue cracks are expected not to grow. By representing the material as a two-dimensional array of beam elements, the nucleation of nonpropagating small cracks at various material locations is modeled via a statistical approach that considers fatigue crack nucleation by accumulation of damage at randomly distributed weak regions. Once nucleated, the fatigue cracks do not propagate but extend only by linking with fatigue cracks subsequently formed in the contiguous elements. Result of the computer simulation suggests that fatigue failure by crack nucleation and coalescence is feasible, but the cycles-to-coalescence is much longer than the cycles-to-initiation for the first crack. Implications of the results in fatigue life assessment based on the Kitagawa diagram are discussed for TiAl alloys.

Chan, K.S. [Southwest Research Inst., San Antonio, TX (United States); Wittowsky, B. [Proctor and Gamble European Service GmbH, Euskirchen (Germany); Pfuff, M. [GKSS Research Center, Geesthacht (Germany)

1999-05-01T23:59:59.000Z

290

Measure the Crack Instead of Construction Vibrations by Charles H. Dowding, Ph.D., P.E.  

E-Print Network [OSTI]

Measure the Crack Instead of Construction Vibrations by Charles H. Dowding, Ph.D., P.E. Figure 1 to address fears of vibration-induced cracking by directly measuring crack response. Relatively inexpensive. HOUSE AND CRACK RESPONSE TO VIBRATIONS Crack measurement concepts are illustrated by the response

291

FITNESS-FOR-SERVICE ASSESSMENT FOR A RADIOACTIVE WASTE TANK THAT CONTAINS STRESS CORROSION CRACKS  

SciTech Connect (OSTI)

Radioactive wastes are confined in 49 underground storage tanks at the Savannah River Site. The tanks are examined by ultrasonic (UT) methods for thinning, pitting, and stress corrosion cracking in order to assess fitness-for-service. During an inspection in 2002, ten cracks were identified on one of the tanks. Given the location of the cracks (i.e., adjacent to welds, weld attachments, and weld repairs), fabrication details (e.g., this tank was not stress-relieved), and the service history the degradation mechanism was stress corrosion cracking. Crack instability calculations utilizing API-579 guidance were performed to show that the combination of expected future service condition hydrostatic and weld residual stresses do not drive any of the identified cracks to instability. The cracks were re-inspected in 2007 to determine if crack growth had occurred. During this re-examination, one indication that was initially reported as a 'possible perpendicular crack <25% through wall' in 2002, was clearly shown not to be a crack. Additionally, examination of a new area immediately adjacent to other cracks along a vertical weld revealed three new cracks. It is not known when these new cracks formed as they could very well have been present in 2002 as well. Therefore, a total of twelve cracks were evaluated during the re-examination. Comparison of the crack lengths measured in 2002 and 2007 revealed that crack growth had occurred in four of the nine previously measured cracks. The crack length extension ranged from 0.25 to 1.8 inches. However, in all cases the cracks still remained within the residual stress zone (i.e., within two to three inches of the weld). The impact of the cracks that grew on the future service of Tank 15 was re-assessed. API-579 crack instability calculations were again performed, based on expected future service conditions and trended crack growth rates for the future tank service cycle. The analysis showed that the combined hydrostatic and weld residual stresses do not drive the identified cracks to instability. This tank expected to be decommissioned in the near future. However, if these plans are delayed, it was recommended that a third examination of selected cracks in the tank be performed in 2014.

Wiersma, B; James Elder, J; Rodney Vandekamp, R; Charles Mckeel, C

2009-04-23T23:59:59.000Z

292

Influence of cracking on the diffusion properties of cement-based materials. Part I: Influence of continuous cracks on the steady-state regime  

SciTech Connect (OSTI)

The influence of traversing cracks on the steady-state diffusion properties of concrete was studied. The effect of both anisotropic and isotropic crack networks was first theoretically assessed using an analytical approach. To simplify the transport equations, cracks were assumed to be of uniform size and evenly distributed on a one- or two-dimensional grid. Results of the theoretical analysis were then compared to experimental data. Both series of results indicate that cracking can markedly alter the diffusion properties of the material and favor the penetration (or the leaching) of drifting species. A simple method to predict the effect of cracking on the concrete diffusivity is proposed. Predictions are made on the basis of two parameters: the crack density and the mean crack aperture. This method can provide a first estimate of the diffusion properties of severely damaged concrete elements.

Gerard, B.; Marchand, J.

2000-01-01T23:59:59.000Z

293

Heating of a testing room by use of a hydrogen-fueled catalytic heater  

Science Journals Connector (OSTI)

Space heating experiments were carried out using flameless (catalytic) combustion of hydrogen with atmospheric oxygen on Pt and oxide catalyst pads. The heating rate required for warming of a testing room was calculated and material balance equations for oxygen depletion and steam production were derived. The following parameters have been investigated: 1. (a) change of the oxygen and water vapour contents in the testing room in comparison with the calculated values, 2. (b) the established thermal regime in the testing room is discussed in comparison with conventional heating. The following conclusions are drawn: 1. (1) The hydrogen combustion can be adjusted to produce the desired temperature level, 2. li(2) in order to maintain the oxygen concentration at the comfort level, the free ventilation in the room should be supplemented by short, periodic, forced ventilation, 3. (3) the comfort limits of humidity require the condensation of the surplus water vapour by using a suitable device.

J. Mercea; E. Grecu; T. Fodor

1981-01-01T23:59:59.000Z

294

Chapter 15 - Catalytic Thermochemical Processes for Biomass Conversion to Biofuels and Chemicals  

Science Journals Connector (OSTI)

Abstract Biomass is the most abundant and biorenewable resource with great potential for sustainable production of chemicals and fuels. Thermochemical conversion technologies (pyrolysis, gasification and hydrothermal liquefaction) are a promising option for transforming biomass feedstocks into liquid oils and chemicals. In the article, for the thermal process of biomass for biofuels and chemicals, the effect of reaction conditions, reactors, solvents and catalysts on the yield and distribution of the products are reviewed. Fast pyrolysis of cellulose is primarily conducted over catalysts with proper acidity/basicity and has undergone many pilot tests. Gasification is typically conducted over supported noble metal catalysts and has been profiled as being CO2-neutral, having a high potential to provide power, chemicals and fuels. Catalytically hydrothermal liquefaction of biomass produces a very complex mixture of liquid products; therefore, novel technology for separation and extraction of downstream products from hydrothermal liquefaction of lignocellulosic biomass need to be developed.

Lin Mei Wu; Chun Hui Zhou; Dong Shen Tong; Wei Hua Yu

2014-01-01T23:59:59.000Z

295

Characterization of geothermal reservoir crack patterns using shear-wave  

Open Energy Info (EERE)

geothermal reservoir crack patterns using shear-wave geothermal reservoir crack patterns using shear-wave splitting Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Characterization of geothermal reservoir crack patterns using shear-wave splitting Details Activities (1) Areas (1) Regions (0) Abstract: Microearthquakes recorded by a downhole, three-component seismic network deployed around the Coso, California, geothermal reservoir since 1992 display distinctive shear-wave splitting and clear polarization directions. From the polarizations the authors estimated three predominant subsurface fracture directions, and from the time delays of the split waves they determined tomographically the 3-D fracture density distribution in the reservoir. Author(s): Lou, M.; Rial, J.A. Published: Geophysics, 3/1/1997

296

Shear-wave splitting and reservoir crack characterization: the Coso  

Open Energy Info (EERE)

Shear-wave splitting and reservoir crack characterization: the Coso Shear-wave splitting and reservoir crack characterization: the Coso geothermal field Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Shear-wave splitting and reservoir crack characterization: the Coso geothermal field Details Activities (1) Areas (1) Regions (0) Abstract: This paper aims to improve current understanding of the subsurface fracture system in the Coso geothermal field, located in east-central California. The Coso reservoir is in active economic development, so that knowledge of the subsurface fracture system is of vital importance for an accurate evaluation of its geothermal potential and day-to-day production. To detect the geometry and density of fracture systems we applied the shear-wave splitting technique to a large number of

297

Stress-corrosion cracking in BWR and PWR piping  

SciTech Connect (OSTI)

Intergranular stress-corrosion cracking of weld-sensitized wrought stainless steel piping has been an increasingly ubiquitous and expensive problem in boiling-water reactors over the last decade. In recent months, numerous cracks have been found, even in large-diameter lines. A number of potential remedies have been developed. These are directed at providing more resistant materials, reducing weld-induced stresses, or improving the water chemistry. The potential remedies are discussed, along with the capabilities of ultrasonic testing to find and size the cracks and related safety issues. The problem has been much less severe to date in pressurized-water reactors, reflecting the use of different materials and much lower coolant oxygen levels.

Weeks, R.W.

1983-07-01T23:59:59.000Z

298

Method for fabrication of crack-free ceramic dielectric films  

DOE Patents [OSTI]

The invention provides a process for forming crack-free dielectric films on a substrate. The process comprise the application of a dielectric precursor layer of a thickness from about 0.3 .mu.m to about 1.0 .mu.m to a substrate. The deposition is followed by low temperature heat pretreatment, prepyrolysis, pyrolysis and crystallization step for each layer. The deposition, heat pretreatment, prepyrolysis, pyrolysis and crystallization are repeated until the dielectric film forms an overall thickness of from about 1.5 .mu.m to about 20.0 .mu.m and providing a final crystallization treatment to form a thick dielectric film. Also provided was a thick crack-free dielectric film on a substrate, the dielectric forming a dense thick crack-free dielectric having an overall dielectric thickness of from about 1.5 .mu.m to about 20.0 .mu.m.

Ma, Beihai; Balachandran, Uthamalingam; Chao, Sheng; Liu, Shanshan; Narayanan, Manoj

2014-02-11T23:59:59.000Z

299

Cracking a Cold Case and Enduring Mystery | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Cracking a Cold Case and Enduring Mystery Cracking a Cold Case and Enduring Mystery Cracking a Cold Case and Enduring Mystery July 1, 2013 - 3:04pm Addthis Chris Brandon of the ROMACONS project collects a sample of ancient Roman concrete drilled from a breakwater in Pozzuoli Bay, near Naples, Italy. The breakwater dates back to roughly 37 B.C. | Photo courtesy of J.P. Oleson. Chris Brandon of the ROMACONS project collects a sample of ancient Roman concrete drilled from a breakwater in Pozzuoli Bay, near Naples, Italy. The breakwater dates back to roughly 37 B.C. | Photo courtesy of J.P. Oleson. Charles Rousseaux Charles Rousseaux Senior Writer, Office of Science What are the key facts? Modern concrete buildings -- most made with Portland cement -- are built to last for a hundred or so years. But Roman concrete has withstood

300

Performance and emission evaluation of biodiesel fueled diesel engine abetted with exhaust gas recirculation and Ni coated catalytic converter  

Science Journals Connector (OSTI)

This article summarizes the results of a laboratory exertion to evaluate the performance and emission parameters of a single cylinder water cooled direct injection diesel engine with and without the aid of exhaust gas recirculation (EGR) as well as with and without the assistance of nickel coated catalytic converter. Neat diesel ethyl esters of waste frying oil (B100) and its diesel blends (B20 and B40) were used as test fuels to assess the various engine operating parameters. Conjointly in this work the effects of emission characteristics by incorporating nickel coated catalytic converter along with 0% 15% and 20% of HOT EGR technique are elaborately discussed. Experimental results proved that the diesel engine operated up to B40 blends assisted by catalytic converter and 15% EGR level showed an adequate reduction in oxides of nitrogen in the exhaust pipe. Also EGR level up to 15% proved reasonable brake thermal efficiency and specific fuel consumption when the test engine operated up to B40 biodiesel-diesel blends.

D. Subramaniam; A. Murugesan; A. Avinash

2013-01-01T23:59:59.000Z

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


301

Weld solidification cracking in 304 to 304L stainless steel  

SciTech Connect (OSTI)

A series of annulus welds were made between 304 and 304L stainless steel coaxial tubes using both pulsed laser beam welding (LBW) and pulsed gas tungsten arc welding (GTAW). In this application, a change in process from pulsed LBW to pulsed gas tungsten arc welding was proposed to limit the possibility of weld solidification cracking since weldability diagrams developed for GTAW display a greater range of compositions that are not crack susceptible relative to those developed for pulsed LBW. Contrary to the predictions of the GTAW weldability diagram, cracking was found. This result was rationalized in terms of the more rapid solidification rate of the pulsed gas tungsten arc welds. In addition, for the pulsed LBW conditions, the material compositions were predicted to be, by themselves, 'weldable' according to the pulsed LBW weldability diagram. However, the composition range along the tie line connecting the two compositions passed through the crack susceptible range. Microstructurally, the primary solidification mode (PSM) of the material processed with higher power LBW was determined to be austenite (A), while solidification mode of the materials processed with lower power LBW apparently exhibited a dual PSM of both austenite (A) and ferrite-austenite (FA) within the same weld. The materials processed by pulsed GT A W showed mostly primary austenite solidification, with some regions of either primary austenite-second phase ferrite (AF) solidification or primary ferrite-second phase austenite (FA) solidification. This work demonstrates that variations in crack susceptibility may be realized when welding different heats of 'weldable' materials together, and that slight variations in processing can also contribute to crack susceptibility.

Hochanadel, Patrick W [Los Alamos National Laboratory; Lienert, Thomas J [Los Alamos National Laboratory; Martinez, Jesse N [Los Alamos National Laboratory; Martinez, Raymond J [Los Alamos National Laboratory; Johnson, Matthew Q [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

302

Weld solidification cracking in 304 to 204L stainless steel  

SciTech Connect (OSTI)

A series of annulus welds were made between 304 and 304L stainless steel coaxial tubes using both pulsed laser beam welding (LBW) and pulsed gas tungsten arc welding (GTAW). In this application, a change in process from pulsed LBW to pulsed gas tungsten arc welding was proposed to limit the possibility of weld solidification cracking since weldability diagrams developed for GTAW display a greater range of compositions that are not crack susceptible relative to those developed for pulsed LBW. Contrary to the predictions of the GTAW weldability diagram, cracking was found.This result was rationalized in terms of the more rapid solidification rate of the pulsed gas tungsten arc welds. In addition, for the pulsed LBW conditions, the material compositions were predicted to be, by themselves, 'weldable' according to the pulsed LBW weldability diagram. However, the composition range along the tie line connecting the two compositions passed through the crack susceptible range. Microstructurally, the primary solidification mode (PSM) of the material processed with higher power LBW was determined to be austenite (A), while solidification mode of the materials processed with lower power LBW apparently exhibited a dual PSM of both austenite (A) and ferrite-austenite (FA) within the same weld. The materials processed by pulsed GTAW showed mostly primary austenite solidification, with some regions of either primary austenite-second phase ferrite (AF) solidification or primary ferrite-second phase austenite (FA) solidification. This work demonstrates that variations in crack susceptibility may be realized when welding different heats of 'weldable' materials together, and that slight variations in processing can also contribute to crack susceptibility.

Hochanadel, Patrick W [Los Alamos National Laboratory; Lienert, Thomas J [Los Alamos National Laboratory; Martinez, Jesse N [Los Alamos National Laboratory; Johnson, Matthew Q [Los Alamos National Laboratory

2010-09-15T23:59:59.000Z

303

Stress intensity factors for small fatigue cracks in tubular joints  

SciTech Connect (OSTI)

Some simple fracture mechanics models are presented for estimating stress intensity factors for small surface fatigue cracks in welded tubular joints. Model predictions are compared with large-scale experimental results for the cases of in-plane and out-of-plane bending in multi-brace tubular nodes. It is demonstrated that reasonably accurate predictions of the stress intensity factor are possible using a modified flat plate solution if the effects of weld geometry, load shedding and crack shape are adequately accounted for.

Monahan, C.C. [Memorial Univ. of Newfoundland, St. Johns, Newfoundland (Canada). Centre for Cold Ocean Resources Engineering; Dover, W.D. [University College, London (United Kingdom)

1995-12-31T23:59:59.000Z

304

Model of crack propagation in a clay soil  

E-Print Network [OSTI]

of independent variables for maximum R to determine A for crack de th, 2 Number of variables in model (p) R Variables in model 0. 703913 0. 916176 0. 988151 0. 997207 0. 999328 H*CLrH*M~CL H, H*M, H~M*CL H, CL, H*M, H*M*CL H, CL, H"M, H*CL, H...: Agricultural Engineering MODEL OF CRACK PROPAGATION IN A CLAY SOIL A Thesis by PATRICK EDWIDGE CARRIERE Approved as to style and content by: John L. Nieber (Chairman of Committee) Donald L. Reddell (Member) Kirk W, Brown (Member ) Wilbert H...

Carriere, Patrick Edwidge

2012-06-07T23:59:59.000Z

305

AQUIFER THERMAL ENERGY STORAGE  

E-Print Network [OSTI]

using aquifers for thermal energy storage. Problems outlinedmatical Modeling of Thermal Energy Storage in Aquifers,"ings of Aquifer Thermal Energy Storage Workshop, Lawrence

Tsang, C.-F.

2011-01-01T23:59:59.000Z

306

A sintering model for thermal barrier coatings R.G. Hutchinson a  

E-Print Network [OSTI]

Turbine blades in the high-pressure, high-temperature stages of gas turbines are manufactured from creep model is developed for the progressive sintering of ceramic columns in a thermal barrier coating made. Explicit calculations are reported for the evolution of sintering within an array of mud-cracked columns

Fleck, Norman A.

307

E-Print Network 3.0 - assisted crack growth Sample Search Results  

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

cal crack growth by stress... for the first time in sapphire for both modes of subcritical cracking. It was found that growth rates were... growth rates could be closely...

308

Monitoring Cracking of a Smectitic Vertisol using Three-dimensional Electrical Resistivity Tomography  

E-Print Network [OSTI]

Upon desiccation, the matrix of Vertisols and other expansive soils shrinks. Matrix shrinkage results in the formation of cracks that can alter the hydrology of the soil. Despite the importance of cracks, many hydrologic models do not account...

Ackerson, Jason Paul

2013-11-20T23:59:59.000Z

309

DOE - Office of Legacy Management -- Catalytic Co - PA 40  

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

Catalytic Co - PA 40 Catalytic Co - PA 40 FUSRAP Considered Sites Site: Catalytic Co. (PA.40 ) Eliminated from further consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Philadelphia , Pennsylvania PA.40-1 Evaluation Year: 1991 PA.40-1 Site Operations: Prime contractor for construction of the Fernald facility. Records indicate one time shipment of a very small quantity (4 lbs) of uranium metal to this site. PA.40-1 Site Disposition: Eliminated - Construction contractor - Potential for residual contamination from the very small quantity of uranium shipped to this site is considered remote PA.40-2 Radioactive Materials Handled: None - as a construction contractor Primary Radioactive Materials Handled: Uranium Metal - Believed to be a Souvenier. PA.40-1

310

Imaging Catalytic Surfaces by Multiplexed Capillary Electrophoresis With Absorption Detection  

SciTech Connect (OSTI)

A new technique for in situ imaging and screening heterogeneous catalysts by using multiplexed capillary electrophoresis with absorption detection was developed. By bundling the inlets of a large number of capillaries, an imaging probe can be created that can be used to sample products formed directly from a catalytic surface with high spatial resolution. In this work, they used surfaces made of platinum, iron or gold wires as model catalytic surfaces for imaging. Various shapes were recorded including squares and triangles. Model catalytic surfaces consisting of both iron and platinum wires in the shape of a cross were also imaged successfully. Each of the two wires produced a different electrochemical product that was separated by capillary electrophoresis. Based on the collected data they were able to distinguish the products from each wire in the reconstructed image.

Michael Christodoulou

2002-08-27T23:59:59.000Z

311

Test results of a catalytic combustor for a gas turbine  

Science Journals Connector (OSTI)

A catalytically assisted low \\{NOx\\} combustor has been developed which has the advantage of catalyst durability. Combustion characteristics of catalysts at high pressure were investigated using a bench scale reactor and an improved catalyst was selected. A combustor for multi-can type gas turbine of 10 MW class was designed and tested at high-pressure conditions using liquefied natural gas (LNG) fuel. This combustor is composed of a burner system and a premixed combustion zone in a ceramic type liner. The burner system consists of catalytic combustor segments and premixing nozzles. Catalyst bed temperature is controlled under 1000°C, premixed gas is injected from the premixing nozzles to catalytic combustion gas and lean premixed combustion is carried out in the premixed combustion zone. As a result of the combustion tests, \\{NOx\\} emission was lower than 5 ppm converted at 16% O2 at a combustor outlet temperature of 1350°C and a combustor inlet pressure of 1.33 MPa.

Y Ozawa; T Fujii; Y Tochihara; T Kanazawa; K Sagimori

1998-01-01T23:59:59.000Z

312

Fuel Flexible, Low Emission Catalytic Combustor for Opportunity Fuel Applications  

SciTech Connect (OSTI)

Limited fuel resources, increasing energy demand and stringent emission regulations are drivers to evaluate process off-gases or process waste streams as fuels for power generation. Often these process waste streams have low energy content and/or highly reactive components. Operability of low energy content fuels in gas turbines leads to issues such as unstable and incomplete combustion. On the other hand, fuels containing higher-order hydrocarbons lead to flashback and auto-ignition issues. Due to above reasons, these fuels cannot be used directly without modifications or efficiency penalties in gas turbine engines. To enable the use of these wide variety of fuels in gas turbine engines a rich catalytic lean burn (RCL®) combustion system was developed and tested in a subscale high pressure (10 atm.) rig. The RCL® injector provided stability and extended turndown to low Btu fuels due to catalytic pre-reaction. Previous work has shown promise with fuels such as blast furnace gas (BFG) with LHV of 85 Btu/ft3 successfully combusted. This program extends on this work by further modifying the combustor to achieve greater catalytic stability enhancement. Fuels containing low energy content such as weak natural gas with a Lower Heating Value (LHV) of 6.5 MJ/m3 (180 Btu/ft3 to natural gas fuels containing higher hydrocarbon (e.g ethane) with LHV of 37.6 MJ/m3 (1010 Btu/ft3) were demonstrated with improved combustion stability; an extended turndown (defined as the difference between catalytic and non-catalytic lean blow out) of greater than 250oF was achieved with CO and NOx emissions lower than 5 ppm corrected to 15% O2. In addition, for highly reactive fuels the catalytic region preferentially pre-reacted the higher order hydrocarbons with no events of flashback or auto-ignition allowing a stable and safe operation with low NOx and CO emissions.

Eteman, Shahrokh

2013-06-30T23:59:59.000Z

313

Detailed modeling of the evaporation and thermal decomposition of urea-water-solution in SCR systems  

E-Print Network [OSTI]

Detailed modeling of the evaporation and thermal decomposition of urea-water-solution in SCRE Journal. Keywords: Multi-component, , evaporation, UWS, Adbue, urea decomposition, thermolysis SCR Catalytic Reduction (SCR) systems. In the multi-component evaporation model, the influence of urea

Boyer, Edmond

314

Applications of the thermal DeNO{sub x} process to FBC boilers  

SciTech Connect (OSTI)

This paper presents graphical and tabular information on Exxon Research and Engineering Company`s proprietary NH{sub 3} based selective non-catalytic nitrogen oxides reduction process. The process is applicable to boilers, incinerators, and fired heaters. Process operating parameters, technology, and equipment are outlined. Thermal performance data and simplified flow diagrams are also presented.

McIntyre, A.D. [Exxon Research & Engineering Company, Florham Park, NJ (United States)

1997-12-31T23:59:59.000Z

315

EARLY-AGE CRACKING REVIEW: MECHANISMS, MATERIAL PROPERTIES,  

E-Print Network [OSTI]

://cementbarriers.org/ and Savannah River National Laboratory website: http://srnl.doe.gov #12;Early-Age Cracking Review: Mechanisms Commission (NRC), the National Institute of Standards and Technology (NIST), the Savannah River National of work performed in part under that contract. This report was prepared in support of the Savannah River

Bentz, Dale P.

316

CONTAINED PLASTIC DEFORMATION NEAR CRACKS AND NOTCHES UNDER LONGITUDINAL SHEAR  

E-Print Network [OSTI]

CONTAINED PLASTIC DEFORMATION NEAR CRACKS AND NOTCHES UNDER LONGITUDINAL SHEAR James R. Rice* ABSTRACT An exact linear elastic-perfectly plastic solution is presented for the problem of a sharp notch coordinates corresponding to given stresses, position of the elastic-plastic boundary, and accompanying

317

Predicting overload-affected fatigue crack growth in steels  

SciTech Connect (OSTI)

The ability of semi-empirical crack closure models to predict the effect of overloads on fatigue crack growth in low-alloy steels has been investigated. With this purpose, the CORPUS model developed for aircraft metals and spectra has been checked first through comparisons between the simulated and observed results for a low-alloy steel. The CORPUS predictions of crack growth under several types of simple load histories containing overloads appeared generally unconservative which prompted the authors to formulate a new model, more suitable for steels. With the latter approach, the assumed evolution of the crack opening stress during the delayed retardation stage has been based on experimental results reported for various steels. For all the load sequences considered, the predictions from the proposed model appeared to be by far more accurate than those from CORPUS. Based on the analysis results, the capability of semi-empirical prediction concepts to cover experimentally observed trends that have been reported for sequences with overloads is discussed. Finally, possibilities of improving the model performance are considered.

Skorupa, M.; Skorupa, A.; Ladecki, B. [Univ. of Mining and Metallurgy, Krakow (Poland). Dept. of Mechanical Engineering and Robotics

1996-12-01T23:59:59.000Z

318

Cracks and Atoms** By Dominic Holland* and Michael Marder  

E-Print Network [OSTI]

Cracks and Atoms** By Dominic Holland* and Michael Marder 1. Introduction Many materials scientists the atomic scale on the mechanical response of materials. On the one hand, there is a reluctance to believe that the invisible atomic scale is important for macroscopic mechanical deformation. Out of sight, out of mind

Texas at Austin. University of

319

Corrosion pitting and environmentally assisted small crack growth  

Science Journals Connector (OSTI)

...of pit geometry and the local pit chemistry. In addition, the pit may have significant microtopographical...these can be found in the work of Burns et al. [29] in relation to...that cracks may initiate near the pit mouth, but the specific location...

2014-01-01T23:59:59.000Z

320

Fatigue crack growth testing of sub-clad defects  

SciTech Connect (OSTI)

Fatigue crack growth tests were performed on four-point bend specimens with cracklike defects intentionally placed in A302B low-alloy pressure vessel steel clad with 308/309L weld-deposited stainless steel. The defects were placed in the base metal under the cladding by machining a cavity from the side opposite the cladding, electric-discharge machining a very sharp flaw, fatigue precracking the flaw, and then filling up the cavity by a weld repair process. The specimens were stress relieved before fatigue testing. The specimens were fatigue cycled at positive load ratios until the defects broke through to the surface. The specimens were then fractured at liquid nitrogen temperatures to reveal the fracture surfaces. Seven different sub-clad flaw specimens were tested in room temperature air and each test provides a record of cycles to defect breakthrough. Changes in defect size and shape as a function of applied load cycles were obtained by beach-marking the crack at various stages of the load history. The results provide a set of embedded defect data which can be used for qualifying fatigue crack growth analysis procedures such as those in Section XI of the ASME boiler and Pressure Vessel Code. A comparison between calculated and measured values shows that the ASME B and PV Section XI fatigue crack growth procedures conservatively predict cycles to defect breakthrough for small sub-clad defects.

Jones, D.P.; Leax, T.R. [Bechtel Bettis, Inc., West Mifflin, PA (United States). Bettis Atomic Power Lab.

1999-08-01T23:59:59.000Z

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


321

Incipient Crack Detection in Composite Wind Turbine Blades  

SciTech Connect (OSTI)

This paper presents some analysis results for incipient crack detection in a 9-meter CX-100 wind turbine blade that underwent fatigue loading to failure. The blade was manufactured to standard specifications, and it underwent harmonic excitation at its first resonance using a hydraulically-actuated excitation system until reaching catastrophic failure. This work investigates the ability of an ultrasonic guided wave approach to detect incipient damage prior to the surfacing of a visible, catastrophic crack. The blade was instrumented with piezoelectric transducers, which were used in an active, pitchcatch mode with guided waves over a range of excitation frequencies. The performance results in detecting incipient crack formation in the fiberglass skin of the blade is assessed over the range of frequencies in order to determine the point at which the incipient crack became detectable. Higher excitation frequencies provide consistent results for paths along the rotor blade's carbon fiber spar cap, but performance falls off with increasing excitation frequencies for paths off of the spar cap. Lower excitation frequencies provide more consistent performance across all sensor paths.

Taylor, Stuart G. [Los Alamos National Laboratory; Choi, Mijin [Chonbuk National University, Korea; Jeong, Hyomi [Chonbuk National University, Korea; Jang, Jae Kyeong [Chonbuk National University, Korea; Park, Gyuhae [Chonnam National University, Korea; Farinholt, Kevin [Commonwealth Center for Advanced Manufacturing, VA; Farrar, Charles R. [Los Alamos National Laboratory; Ammerman, Curtt N. [Los Alamos National Laboratory; Todd, Michael D. [Los Alamos National Laboratory; Lee, Jung-Ryul [Chonbuk National University, Korea

2012-08-28T23:59:59.000Z

322

A new approach to the subcritical cracking of ceramic Pierre Ladev`eze,a,1  

E-Print Network [OSTI]

A new approach to the subcritical cracking of ceramic fibers Pierre Ladev`eze,a,1 , Martin Geneta a Cachan Cedex, France Abstract A new modeling approach to subcritical crack propagation (i.e. static fa, the result comes down to the widely-used Paris-like subcritical crack propagation law. For the general case

323

Average crack front velocity during subcritical fracture propagation in a heterogeneous medium  

E-Print Network [OSTI]

Average crack front velocity during subcritical fracture propagation in a heterogeneous medium relaxation tests, exploring subcritical to critical regimes. Transparency of the material (PMMA) allows kinetic crack propagation is usually referred to as sub-critical crack growth or sub- critical regime

Paris-Sud XI, Université de

324

On the physics of moisture-induced cracking in metal-glass ,,copper-silica... interfaces  

E-Print Network [OSTI]

September 2007 Environmentally dependent subcritical crack growth, or stress-corrosion cracking, along on the moisture content in gaseous environments. Water and several organic liquids, namely n-butanol, methanol, additionally, subcritical crack growth17 and cyclically induced fracture18 at or near these interfaces when

Ritchie, Robert

325

Stress corrosion cracking under low stress: Continuous or discontinuous Longkui K. Zhu a  

E-Print Network [OSTI]

Stress corrosion cracking under low stress: Continuous or discontinuous cracks? Longkui K. Zhu a , Yu Yan a , Jinxu X. Li a , Lijie J. Qiao a, , Alex A. Volinsky b,a a Corrosion and Protection Center. Stress corrosion C. Anodic dissolution a b s t r a c t Two-dimensional and three-dimensional crack

Volinsky, Alex A.

326

Influence of Impurity Segregation on Temper Embrittlement and on Slow Fatigue Crack  

E-Print Network [OSTI]

of segregated impurity atoms (temper embrittlement) and hydrogen atoms, evolved from crack tip surface reactions with water vapor in the moist air environment (hydrogen embrittlement). The signifi- cance of crack closureInfluence of Impurity Segregation on Temper Embrittlement and on Slow Fatigue Crack Growth

Ritchie, Robert

327

Brittle fracture in a periodic structure with internal potential energy. Spontaneous crack propagation  

Science Journals Connector (OSTI)

...with the crack speed-energy relation is presented...crack-related dynamic Green's function. For anisotropic...crack-related dynamic Green's function Note that...absence of the internal energy was considered in [14] without evaluation of the Green's function (also see...

2014-01-01T23:59:59.000Z

328

MICRO-METER MEASUREMENT OF CRACKS TO COMPARE BLAST AND ENVIRONMENTAL EFFECTS.  

E-Print Network [OSTI]

to development of a new approach to vibration monitoring called autonomous crack measurement (ACM vibration time histories. Measurements reported herein show that weather- induced response of cracksMICRO-METER MEASUREMENT OF CRACKS TO COMPARE BLAST AND ENVIRONMENTAL EFFECTS. Charles H Dowding

329

The Application of Reliability-Based Design Factors In Stress Corrosion Cracking Evaluations  

SciTech Connect (OSTI)

First-order reliability methodology (FORM) is used to develop reliability-based design factors for deterministic analyses of stress corrosion cracking. The basic elements of FORM as applied to structural reliability problems are reviewed and then employed specifically to stress corrosion cracking evaluations. Failure due to stress corrosion cracking is defined as crack initiation followed by crack growth to a critical depth. The stress corrosion cracking process is thus represented in terms of a crack initiation time model and a crack growth rate model, with the crack growth rate integrated from the initiation time to the time at which the crack grows to its critical depth. Both models are described by log-normal statistical distribution functions. A procedure is developed to evaluate design factors that are applied to the mean values of the crack initiation time and the crack growth rate for specified temperature and stress conditions. The design factors, which depend on the standard deviations of the statistical distributions, are related to a target reliability, which is inversely related to an acceptable probability of failure. The design factors are not fixed, but are evaluated on a case-to-case basis for each application. The use of these design factors in a deterministic analysis assures that the target reliability will be attained and the corresponding acceptable probability of failure will not be exceeded. An example problem illustrates use of this procedure.

E. Friedman

2001-12-20T23:59:59.000Z

330

White(etching!matter!in!bearing!steel! Part1:!Controlled(cracking!of!52100!steel!  

E-Print Network [OSTI]

! 1! White(etching!matter!in!bearing!steel! Part1:!Controlled(cracking!of!52100!steel! ! W!phenomena!such!as!the!appearance!of!"white(etching!areas"!or!"white(etching! cracks",!crack!particular!kind!of!microstructural!damage!in!the!form!of!regions!of!the! structure,! which! appear! white! in

Cambridge, University of

331

ensl-00138774,version1-27Mar2007 Slow crack growth: models and experiments  

E-Print Network [OSTI]

the subcritical growth of a single crack in thin sheets of paper. A good agreement between the theoreticalensl-00138774,version1-27Mar2007 Slow crack growth: models and experiments S. Santucci, L. Vanel, S'Italie, 69364 Lyon Cedex 07, France March 28, 2007 Abstract The properties of slow crack growth in brittle

Paris-Sud XI, Université de

332

J Am Cerom Soc 73 [4]893-903 (1990) Cyclic Fatigue-Crack Propagation in  

E-Print Network [OSTI]

InternationalScience Center, Thousand Oaks, California 91360 The subcritical growth of fatigue cracks under variable-amplitude cyclic loading, crack-growth rates show transient accelera- tions following low overloads, again analogous to behavior commonly observed in ductile metals. Cyclic crack-growth rates

Ritchie, Robert

333

Biomaterials 28 (2007) 49014911 Stresscorrosion crack growth of SiNaKMgCaPO bioactive  

E-Print Network [OSTI]

Elsevier Ltd. All rights reserved. Keywords: Stress corrosion; Bioactive glass; Subcritical crack growthBiomaterials 28 (2007) 4901­4911 Stress­corrosion crack growth of Si­Na­K­Mg­Ca­P­O bioactive Available online 21 August 2007 Abstract This paper describes research on the stress­corrosion crack growth

Ritchie, Robert

334

Chemistry, phase formation, and catalytic activity of thin palladium-containing oxide films synthesized by plasma-assisted physical vapor deposition  

SciTech Connect (OSTI)

The chemistry, microstructure, and catalytic activity of thin films incorporating palladium were studied using scanning and transmission electron microscopies, X-ray diffraction, spectrophotometry, 4-point probe and catalytic tests. The films were synthesized using pulsed filtered cathodic arc and magnetron sputter deposition, i.e. techniques far from thermodynamic equilibrium. Catalytic particles were formed by thermally cycling thin films of the Pd-Pt-O system. The evolution and phase formation in such films as a function of temperature were discussed in terms of the stability of PdO and PtO2 in air. The catalytic efficiency was found to be strongly affected by the chemical composition, with oxidized palladium definitely playing a major role in the combustion of methane. Reactive sputter deposition of thin films in the Pd-Zr-Y-O system allowed us forming microstructures ranging from nanocrystalline zirconia to palladium nanoparticles embedded in a (Zr,Y)4Pd2O matrix. The sequence of phase formation is put in relation to simple thermodynamic considerations.

Anders, Andre

2010-11-26T23:59:59.000Z

335

Use of Pd membranes in catalytic reactors for steam methane reforming for pure hydrogen production  

Science Journals Connector (OSTI)

This review analyzes publications on experimental studies and mathematical modeling in the field of development of a catalytic reformer (mainly, steam methane conversion) with a fixed catalytic bed. The specif...

A. B. Shigarov; V. D. Meshcheryakov…

2011-10-01T23:59:59.000Z

336

Impact of Biodiesel-Based Na on the Selective Catalytic Reduction...  

Broader source: Energy.gov (indexed) [DOE]

Impact of Biodiesel-Based Na on the Selective Catalytic Reduction (SCR) of NOx Using Cu-zeolite Impact of Biodiesel-Based Na on the Selective Catalytic Reduction (SCR) of NOx Using...

337

E-Print Network 3.0 - atpase catalytic domain Sample Search Results  

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

impressive progress has been made in understanding of the catalytic mechanism of F-type ATP synthase, which is the key enzyme in the energy metabolism of Summary: of the catalytic...

338

Utilization and Mitigation of VAM/CMM Emissions by a Catalytic Combustion Gas Turbine  

Science Journals Connector (OSTI)

A system configured with a catalytic combustion gas turbine generator unit is introduced. The system has ... Heavy Industries, Ltd., such as small gas turbines, recuperators and catalytic combustors, and catalyti...

K. Tanaka; Y. Yoshino; H. Kashihara; S. Kajita

2013-01-01T23:59:59.000Z

339

Process analysis of syngas production by non-catalytic POX of oven gas  

Science Journals Connector (OSTI)

A non-catalytic POX of oven gas is proposed to solve the problem of secondary pollution due to solid wastes produced from the great amount of organic sulfur contained in oven gas in the traditional catalytic p...

Fuchen Wang; Xinwen Zhou; Wenyuan Guo…

2009-03-01T23:59:59.000Z

340

WATTS TOWERS: THE EFFECTS OF THERMAL CYCLES ON THE FORMATION AND BEHAVIOR OF CRACKS  

E-Print Network [OSTI]

to make lasting repairs to the Watts Towers. 15 REFERENCES [1] LSTC. "LS-DYNA KEYWROD MANUAL." DYNA Support. Livermore Software Technology Corporation, n.d. Web. 5 Apr. 2013.

Spencer, Matthew T

2013-02-06T23:59:59.000Z

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


341

Estimation of Damage to the Collector of a Water Economizer by Thermal Fatigue Cracks  

Science Journals Connector (OSTI)

We study defects formed on the outer and inner surfaces of the input collector of water economizer of a TPP-312 boiler at the...

R. Ya. Kosarevych; O. Z. Student; Ya. D. Onyshchak; A. D. Markov…

2004-01-01T23:59:59.000Z

342

High Performance Catalytic Heat Exchanger for SOFC Systems - FuelCell Energy  

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

Catalytic Heat Catalytic Heat Exchanger for SOFC Systems-FuelCell Energy Background In a typical solid oxide fuel cell (SOFC) power generation system, hot (~900 °C) effluent gas from a catalytic combustor serves as the heat source within a high-temperature heat exchanger, preheating incoming fresh air for the SOFC's cathode. The catalytic combustor and the cathode air heat exchanger together represent the largest opportunity for cost

343

Fuel-Flexible, Low-Emissions Catalytic Combustor for Opportunity Fuels  

Broader source: Energy.gov [DOE]

Factsheet overview of how project will develop a unique, feul-flexible catalytic combustor for gas turbines

344

Thermal Shock-resistant Cement  

SciTech Connect (OSTI)

We studied the effectiveness of sodium silicate-activated Class F fly ash in improving the thermal shock resistance and in extending the onset of hydration of Secar #80 refractory cement. When the dry mix cement, consisting of Secar #80, Class F fly ash, and sodium silicate, came in contact with water, NaOH derived from the dissolution of sodium silicate preferentially reacted with Class F fly ash, rather than the #80, to dissociate silicate anions from Class F fly ash. Then, these dissociated silicate ions delayed significantly the hydration of #80 possessing a rapid setting behavior. We undertook a multiple heating -water cooling quenching-cycle test to evaluate the cement’s resistance to thermal shock. In one cycle, we heated the 200 and #61616;C-autoclaved cement at 500 and #61616;C for 24 hours, and then the heated cement was rapidly immersed in water at 25 and #61616;C. This cycle was repeated five times. The phase composition of the autoclaved #80/Class F fly ash blend cements comprised four crystalline hydration products, boehmite, katoite, hydrogrossular, and hydroxysodalite, responsible for strengthening cement. After a test of 5-cycle heat-water quenching, we observed three crystalline phase-transformations in this autoclaved cement: boehmite and #61614; and #61543;-Al2O3, katoite and #61614; calcite, and hydroxysodalite and #61614; carbonated sodalite. Among those, the hydroxysodalite and #61614; carbonated sodalite transformation not only played a pivotal role in densifying the cementitious structure and in sustaining the original compressive strength developed after autoclaving, but also offered an improved resistance of the #80 cement to thermal shock. In contrast, autoclaved Class G well cement with and without Class F fly ash and quartz flour failed this cycle test, generating multiple cracks in the cement. The major reason for such impairment was the hydration of lime derived from the dehydroxylation of portlandite formed in the autoclaved cement, causing its volume to expand.

Sugama T.; Pyatina, T.; Gill, S.

2012-02-01T23:59:59.000Z

345

The Biodiversity of Catalytic Super-Brownian Motion Klaus Fleischmann  

E-Print Network [OSTI]

The Biodiversity of Catalytic Super-Brownian Motion Klaus Fleischmann WeierstraÃ?-Institut f that the reactant has an infinite local biodiversity or genetic abundance. This contrasts the finite local biodiversity of the equilibrium of classical super-Brownian motion. Another question we address

Klenke, Achim

346

Short Communication Catalytic coal gasification: use of calcium versus potassium*  

E-Print Network [OSTI]

Short Communication Catalytic coal gasification: use of calcium versus potassium* Ljubisa R on the gasification in air and 3.1 kPa steam of North Dakota lignitic chars prepared under slow and rapid pyrolysis of calcium is related to its sintering via crystallite growth. (Keywords: coal; gasification; catalysis

347

Catalytic Domain of Phosphoinositide-specific Phospholipase C (PLC)  

E-Print Network [OSTI]

Catalytic Domain of Phosphoinositide-specific Phospholipase C (PLC) MUTATIONAL ANALYSIS OF RESIDUES WITHIN THE ACTIVE SITE AND HYDROPHOBIC RIDGE OF PLC 1* (Received for publication, November 20, 1997 Institute, University of Dundee, Dundee DD1 4HN, United Kingdom Structural studies of phospholipase C 1 (PLC

Williams, Roger L.

348

Production of Syngas by Direct Catalytic Oxidation of Methane  

Science Journals Connector (OSTI)

...DESORPTION AT HIGH-TEMPERATURES...of abundant natural gas into liquid...a 50-mI high-pressure Autoclave...atmospheric pressure, and the...with very high CH4 yields...Contact times of gases within the...catalytic combustors and reactors...

D. A. Hickman; L. D. Schmidt

1993-01-15T23:59:59.000Z

349

Ex-Situ Catalytic Fast Pyrolysis Technology Pathway  

SciTech Connect (OSTI)

This technology pathway case investigates converting woody biomass using ex-situ catalytic fast pyrolysis followed by upgrading to gasoline-, diesel-, and jet-range hydrocarbon blendstocks. Technical barriers and key research needs that should be pursued for this pathway to be competitive with petroleum-derived blendstocks have been identified.

Biddy, M.; Dutta, A.; Jones, S.; Meyer, A.

2013-03-01T23:59:59.000Z

350

In-Situ Catalytic Fast Pyrolysis Technology Pathway  

SciTech Connect (OSTI)

This technology pathway case investigates converting woody biomass using in-situ catalytic fast pyrolysis followed by upgrading to gasoline-, diesel-, and jet-range hydrocarbon blendstocks. Technical barriers and key research needs that should be pursued for this pathway to be competitive with petroleum-derived blendstocks have been identified.

Biddy, M.; Dutta, A.; Jones, S.; Meyer, A.

2013-03-01T23:59:59.000Z

351

Scaling behavior of optimally structured catalytic microfluidic reactors  

E-Print Network [OSTI]

In this study of catalytic microfluidic reactors we show that, when optimally structured, these reactors share underlying scaling properties. The scaling is predicted theoretically and verified numerically. Furthermore, we show how to increase the reaction rate significantly by distributing the active porous material within the reactor using a high-level implementation of topology optimization.

Okkels, F; Bruus, Henrik; Okkels, Fridolin

2006-01-01T23:59:59.000Z

352

Nanostructured Molybdenum Carbide: Sonochemical Synthesis and Catalytic Properties  

E-Print Network [OSTI]

to be a useful technique to generate nanophase transition metals.7,8 Recently, molybdenum and tungsten carbides of metal salts.5,6 Sonochemical decomposition of transition metal carbonyl compounds has also been provenNanostructured Molybdenum Carbide: Sonochemical Synthesis and Catalytic Properties Taeghwan Hyeon

Suslick, Kenneth S.

353

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of polycarbonate and plastic waste to recover monomers  

DOE Patents [OSTI]

A process is described using fast pyrolysis to convert a plastic waste feed stream containing polycarbonate and ABS to high value monomeric constituents prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of a given polymer to its high value monomeric constituents prior to a temperature range that causes pyrolysis of other plastic components; selecting an acid or base catalysts and an oxide or carbonate support for treating the feed stream to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of the high value monomeric constituents of polycarbonate and ABS in the first temperature program range; differentially heating the feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituents prior to pyrolysis or other plastic components; separating the high value monomeric constituents from the polycarbonate to cause pyrolysis to a different high value monomeric constituent of the plastic waste and differentially heating the feed stream at the second higher temperature program range to cause pyrolysis of different high value monomeric constituents; and separating the different high value monomeric constituents. 68 figs.

Evans, R.J.; Chum, H.L.

1994-06-14T23:59:59.000Z

354

Ultrasonic Flaw Detection of Cracks and Machined Flaws as Observed Through Austenitic Stainless Steel Piping Welds  

SciTech Connect (OSTI)

Piping welds in the pressure boundary of light water reactors (LWRs) are subject to a volumetric examination based on Section XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. Due to access limitations and high background radiation levels, the technique used is primarily ultrasonic rather than radiographic. Many of the austenitic welds in safety-related piping systems provide limited access to both sides of the weld, so a far-side examination is necessary. Historically, far-side inspections have performed poorly because of the coarse and elongated grains that make up the microstructures of austenitic weldments. The large grains cause the ultrasound to be scattered, attenuated, and redirected. Additionally, grain boundaries or weld geometry may reflect coherent ultrasonic echoes, making flaw detection and discrimination a more challenging endeavor. Previous studies conducted at the Pacific Northwest National Laboratory (PNNL) on ultrasonic far-side examinations in austenitic piping welds involved the application of conventional transducers, use of low-frequency Synthetic Aperture Focusing Techniques (SAFT), and ultrasonic phased-array (PA) methods on specimens containing implanted thermal fatigue cracks and machined reflectors [1-2]. From these studies, PA inspection provided the best results, detecting nearly all of the flaws from the far side. These results were presented at the Fifth International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurised Components in 2006. This led to an invitation to examine field-removed specimens containing service-induced intergranular stress corrosion cracks (IGSCC) at the Electric Power Research Institute’s (EPRI) Nondestructive Evaluation (NDE) Center, in Charlotte, North Carolina. Results from this activity are presented.

Anderson, Michael T.; Cinson, Anthony D.; Crawford, Susan L.; Cumblidge, Stephen E.; Diaz, Aaron A.

2009-07-01T23:59:59.000Z

355

Chapter 22 - Heterogeneous Catalytic Reduction for Water Purification: Nanoscale Effects on Catalytic Activity, Selectivity, and Sustainability  

Science Journals Connector (OSTI)

Reductive catalysis is a promising water treatment technology that employs heterogeneous metal catalysts (e.g., Pd nanoparticles on a support) to convert dihydrogen to adsorbed atomic hydrogen in order to promote reactions with functional groups in various contaminants. Reductive catalysis has several potential advantages, including high selectivity for a given target, fast rates under mild conditions, and low production of harmful by-products. The technology has been applied mostly for remediation of groundwater contaminated with halogenated hydrocarbons and for treatment of nitrate, but recent studies have expanded the range of target contaminants to include perchlorate and N-nitrosamines. Palladium-based catalysts hold tremendous promise for their ability to selectively destroy several drinking water contaminants, and some compounds that exhibit slow reaction kinetics with Pd alone are rapidly degraded when a second, promoter metal is added to the catalyst. However, there is a lack of information about the long-term sustainability of these catalytic treatment processes, which is a major consideration in their possible adoption for remediation applications. Recent research has focused on the nanoscale characterization of these heterogeneous catalysts in order to develop an improved understanding of their mechanisms of deactivation and the pathways for regeneration. Two examples of studies from the authors’ laboratories, involving (i) hydrodehalogenation of iodinated X-ray contrast media with Ni or Pd catalysts and (ii) selective reduction of nitrate with a regenerable Pd-In/alumina catalyst, are discussed in this chapter.

Timothy J. Strathmann; Charles J. Werth; John R. Shapley

2014-01-01T23:59:59.000Z

356

EFFECT OF UNBROKEN LIGAMENTS ON STRESS CORROSION CRACKING BEHAVIOR OF ALLOY 82H WELDS  

SciTech Connect (OSTI)

Previously reported stress corrosion cracking (SCC) rates for Alloy 82H gas-tungsten-arc welds tested in 360 C water showed tremendous variability. The excessive data scatter was attributed to the variations in microstructure, mechanical properties and residual stresses that are common in welds. In the current study, however, re-evaluation of the SCC data revealed that the large data scatter was an anomaly due to erroneous crack growth rates inferred from crack mouth opening displacement (CMOD) measurements. Apparently, CMOD measurements provided reasonably accurate SCC rates for some specimens, but grossly overestimated rates in others. The overprediction was associated with large unbroken ligaments that often form in welds in the wake of advancing crack fronts. When ligaments were particularly large, they prevented crack mouth deflection, so apparent crack incubation times (i.e. period of time before crack advance commences) based on CMOD measurements were unrealistically long. During the final states of testing, ligaments began to separate allowing the crack mouth to open rather quickly. This behavior was interpreted as a rapid crack advance, but it actually reflects the ligament separation rate, not the SCC rate. Revised crack growth rates obtained in this study exhibit substantially less scatter than that previously reported. The effects of crack orientation and fatigue flutter loading on SCC rates in 82H welds are also discussed.

Mills, W.J. and Brown, C.M.

2003-02-20T23:59:59.000Z

357

Characteristics of lead induced stress corrosion cracking of alloy 690 in high temperature  

SciTech Connect (OSTI)

Slow strain rate tests (SSRT) were conducted on alloy 690 in various lead chloride solutions and metal lead added to 100 ppm chloride solution at 288 C. The corrosion potential (rest potential) for the alloy was measured with SSRT tests. The cracking was observed by metallographic examination and electron probe micro analyzer. Also, the corrosion behavior of the alloy was evaluated by anodic polarized measurement at 30 C. Resulting from the tests, cracking was characterized by cracking behavior, crack length and crack growth rate, and lead effects on cracking. The cracking was mainly intergranular in mode, approximately from 60 um to 450 um in crack length, and approximately 10{sup {minus}6} to 10{sup {minus}7} mmS-1 in crack velocity. The cracking was evaluated through the variation the corrosion potential in potential-time and lead behavior during SSRTs. The lead effect in corrosion was evaluated through active to passive transition behavior in anodic polarized curves. The corrosion reactions in the cracking region were confirmed by electron probe microanalysis. Alloy 690 is used for steam generation tubes in pressurized water reactors.

Chung, K.K. [Korea Inst. of Nuclear Safety, Taejon (Korea, Republic of); Lim, J.K. [Chonbuk National Univ., Chonju (Korea, Republic of); Watanabe, Yutaka; Shoji, Tetsuo [Tohoku Univ., Sendai (Japan). Research Inst. for Fracture Technology

1996-10-01T23:59:59.000Z

358

Fatigue and Creep Crack Propagation behaviour of Alloy 617 in the Annealed and Aged Conditions  

SciTech Connect (OSTI)

The crack propagation behaviour of Alloy 617 was studied under various conditions. Elevated temperature fatigue and creep-fatigue crack growth experiments were conducted at 650 and 800 degrees C under constant stress intensity (triangle K) conditions and triangular or trapezoidal waveforms at various frequencies on as-received, aged, and carburized material. Environmental conditions included both laboratory air and characteristic VHTR impure helium. As-received Alloy 617 displayed an increase in the crack growth rate (da/dN) as the frequency was decreased in air which indicated a time-dependent contribution component in fatigue crack propagation. Material aged at 650°C did not display any influence on the fatigue crack growth rates nor the increasing trend of crack growth rate with decreasing frequency even though significant microstructural evolution, including y’ (Ni3Al) after short times, occurred during aging. In contrast, carburized Alloy 617 showed an increase in crack growth rates at all frequencies tested compared to the material in the standard annealed condition. Crack growth studies under quasi-constant K (i.e. creep) conditions were also completed at 650 degrees C and a stress intensity of K = 40 MPa9 (square root)m. The results indicate that crack growth is primarily intergranular and increased creep crack growth rates exist in the impure helium environment when compared to the results in laboratory air. Furthermore, the propagation rates (da/dt) continually increased for the duration of the creep crack growth either due to material aging or evolution of a crack tip creep zone. Finally, fatigue crack propagation tests at 800 degrees C on annealed Alloy 617 indicated that crack propagation rates were higher in air than impure helium at the largest frequencies and lowest stress intensities. The rates in helium, however, eventually surpass the rates in air as the frequency is reduced and the stress intensity is decreased which was not observed at 650 degrees C.

Julian K. Benz; Richard N. Wright

2013-10-01T23:59:59.000Z

359

On the application of bees algorithm to the problem of crack detection of beam-type structures  

Science Journals Connector (OSTI)

In this paper, the application of the bees algorithm (BA) to the problem of crack detection in beams is introduced. A numerical as well as an experimental study is designed to predict a single open edge-crack in cantilever beams. The crack is modeled ... Keywords: Bees algorithm, Cantilever beam, Crack detection, Modal testing, Particle swarm optimization

S. Moradi; P. Razi; L. Fatahi

2011-12-01T23:59:59.000Z

360

Relationship between the properties of iron sulfides and their catalytic activity  

SciTech Connect (OSTI)

Iron sulfides, such as pyrite, are known catalysts in coal liquefaction and produce significant increases in both conversion and distillate (850 F/sup -/) yield. The main objective of this work is to increase the catalytic activity of iron sulfides by systematically changing the following properties: composition, source, particle size, surface area, morphology and defect level. Several iron sulfides have been synthesized including pyrite (FeS/sub 2/) with 46.6 wt % Fe, pyrrhotite (Fe/sub 1-x/S) with about 60 wt % Fe and mackinawite (Fe/sub 9/S/sub 8/) with 66.2 wt % Fe. The source variations have included commercial material and minerals. The pyrite particle sizes ranged from -350 to -5..mu..m, the pyrite surface areas varied from 2 to >10 m/sup 2//g, the mackinawite surface areas ranged from 40 to 80 m/sup 2//g, and pyrite morphologies included massive material and a concentrate of framboids from Iowa coal. Moessbauer studies of the pyrrhotites in coal liquefaction residues have shown that there is a direct correlation between conversion and the number of vacancies in the pyrrhotite. Pyrites with enhanced defect levels were prepared by explosively shock loading Robena pyrite at 15 GPa. All these materials have been tested in either tubing reactor or autoclave runs with West Virginia Blacksville No. 2 coal and SRC-II heavy distillate (550/sup 0/F/sup +/). The runs were carried out at 425/sup 0/C, 500 psi H/sub 2/ (cold charge) for 30 minutes with a 7.5 wt % catalyst loading. All these materials have shown catalytic effects as compared to uncatalyzed thermal runs.

Stohl, F.V.; Granoff, B.

1981-01-01T23:59:59.000Z

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361

Method for making dense crack free thin films  

DOE Patents [OSTI]

The process described herein provides a simple and cost effective method for making crack free, high density thin ceramic film. The steps involve depositing a layer of a ceramic material on a porous or dense substrate. The deposited layer is compacted and then the resultant laminate is sintered to achieve a higher density than would have been possible without the pre-firing compaction step.

Jacobson, Craig P. (Lafayette, CA); Visco, Steven J. (Berkeley, CA); De Jonghe, Lutgard C. (Lafayette, CA)

2007-01-16T23:59:59.000Z

362

Environmentally assisted cracking of light-water reactor materials  

SciTech Connect (OSTI)

Environmentally assisted cracking (EAC) of lightwater reactor (LWR) materials has affected nuclear reactors from the very introduction of the technology. Corrosion problems have afflicted steam generators from the very introduction of pressurized water reactor (PWR) technology. Shippingport, the first commercial PWR operated in the United States, developed leaking cracks in two Type 304 stainless steel (SS) steam generator tubes as early as 1957, after only 150 h of operation. Stress corrosion cracks were observed in the heat-affected zones of welds in austenitic SS piping and associated components in boiling-water reactors (BRWs) as early as 1965. The degradation of steam generator tubing in PWRs and the stress corrosion cracking (SCC) of austenitic SS piping in BWRs have been the most visible and most expensive examples of EAC in LWRs, and the repair and replacement of steam generators and recirculation piping has cost hundreds of millions of dollars. However, other problems associated with the effects of the environment on reactor structures and components am important concerns in operating plants and for extended reactor lifetimes. Cast duplex austenitic-ferritic SSs are used extensively in the nuclear industry to fabricate pump casings and valve bodies for LWRs and primary coolant piping in many PWRs. Embrittlement of the ferrite phase in cast duplex SS may occur after 10 to 20 years at reactor operating temperatures, which could influence the mechanical response and integrity of pressure boundary components during high strain-rate loading (e.g., seismic events). The problem is of most concern in PWRs where slightly higher temperatures are typical and cast SS piping is widely used.

Chopra, O.K.; Chung, H.M.; Kassner, T.F.; Shack, W.J.

1996-02-01T23:59:59.000Z

363

Direct Observation and Image-Based Simulation of Three-Dimensional Tortuous Crack Evolution inside Opaque Materials  

Science Journals Connector (OSTI)

We present a combined novel methodology to study the three-dimensional complex geometry of a tortuous crack and identify the essential features of the crack and its propagation inside a heterogeneous material. We find that some severe damage events occur unexpectedly below a local mode-I crack within the sample; we realize that the severe plastic zone of the local mode-I crack is shifted down by another unseen crack segment hidden behind, which is responsible for the unusual damage phenomenon observed. We also find that the crack grows fast at some locations but slowly at some other locations along the crack front; we recognize that the crack-tip fields are reduced by neighboring hidden crack segments, which accounts for the retarded propagation of some part of the crack front. The feasibility and power of the proposed methodology highlights the potential of a new way to study fracture mechanisms in real materials.

Lihe Qian; Hiroyuki Toda; Kentaro Uesugi; Masakazu Kobayashi; Toshiro Kobayashi

2008-03-21T23:59:59.000Z

364

Mixed-mode, high-cycle fatigue-crack growth thresholds in I. A comparison of large-and short-crack behavior  

E-Print Network [OSTI]

) in a Ti±6Al±4V turbine blade alloy with a bimodal microstructure. Speci®cally, the eect of combined mode I machined to within $200 lm of the precrack tip. For such short cracks, wherein the magnitude of crack, particularly in association with fretting fatigue in the blade dovetail/disk contact section [3]. For fatigue

Ritchie, Robert

365

To Crack or Not to Crack: Strain in High TemperatureSuperconductors  

SciTech Connect (OSTI)

Round wire Bi 2212 is emerging as a viable successor ofNb3Sn in High Energy Physics and Nuclear Magnetic Resonance, to generatemagnetic fields that surpass the intrinsic limitations of Nb3Sn. Ratherbold claims are made on achievable magnetic fields in applications usingBi 2212, due to the materials' estimated critical magnetic field of 100 Tor higher. High transport currents in high magnetic fields, however, leadto large stress on, and resulting large strain in the superconductor. Theeffect of strain on the critical properties of Bi-2212 is far fromunderstood, and strain is, as with Nb3Sn, often treated as a secondaryparameter in the design of superconducting magnets. Reversibility of thestrain induced change of the critical surface of Nb3Sn, points to anelectronic origin of the observed strain dependence. Record breaking highfield magnets are enabled by virtue of such reversible behavior. Straineffects on the critical surface of Bi-2212, in contrast, are mainlyirreversible and suggest a non-electronic origin of the observed straindependence, which appears to be dominated by the formation of cracks inthe superconductor volumes. A review is presented of available results onthe effects of strain on the critical surface of Bi-2212, Bi-2223 andYBCO. It is shown how a generic behavior emerges for the (axial) straindependence of the critical current density, and how the irreversiblereduction of the critical current density is dominated by strain inducedcrack formation in the superconductor. From this generic model it becomesclear that magnets using high temperature superconductors will be strainlimited far before the intrinsic magnetic field limitations will beapproached, or possibly even before the magnetic field limitation ofNb3Sn can be surpassed. On a positive note, in a very promising recentresult from NIST on the axial strain dependence of the critical currentdensity in extremely well aligned YBCO, reversible behavior was observed.This result emphasizes the need for further conductor development,specifically for round wire Bi-2212, to generate a wire with a similarreversible dependence on strain. Availability of such a wire will enablethe construction of magnets that can indeed generate fields that farsurpass the limitations of Nb3Sn superconductors.

Godeke, Arno

2007-08-22T23:59:59.000Z

366

Assessment of Crack Detection in Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-Frequency Ultrasonic Methods  

SciTech Connect (OSTI)

Studies conducted at the Pacific Northwest National Laboratory in Richland, Washington, have focused on assessing the effectiveness and reliability of novel approaches to nondestructive examination (NDE) for inspecting coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the U.S. Nuclear Regulatory Commission on the effectiveness and reliability of advanced NDE methods as related to the inservice inspection of safety-related components in pressurized water reactors (PWRs). This report provides progress, recent developments, and results from an assessment of low frequency ultrasonic testing (UT) for detection of inside surface-breaking cracks in cast stainless steel reactor piping weldments as applied from the outside surface of the components. Vintage centrifugally cast stainless steel piping segments were examined to assess the capability of low-frequency UT to adequately penetrate challenging microstructures and determine acoustic propagation limitations or conditions that may interfere with reliable flaw detection. In addition, welded specimens containing mechanical and thermal fatigue cracks were examined. The specimens were fabricated using vintage centrifugally cast and statically cast stainless steel materials, which are typical of configurations installed in PWR primary coolant circuits. Ultrasonic studies on the vintage centrifugally cast stainless steel piping segments were conducted with a 400-kHz synthetic aperture focusing technique and phased array technology applied at 500 kHz, 750 kHz, and 1.0 MHz. Flaw detection and characterization on the welded specimens was performed with the phased array method operating at the frequencies stated above. This report documents the methodologies used and provides results from laboratory studies to assess baseline material noise, crack detection, and length-sizing capability for low-frequency UT in cast stainless steel piping.

Anderson, Michael T.; Crawford, Susan L.; Cumblidge, Stephen E.; Denslow, Kayte M.; Diaz, Aaron A.; Doctor, Steven R.

2007-03-01T23:59:59.000Z

367

Effects of stress ratio and fiber orientation on fatigue crack growth behavior in APAL  

SciTech Connect (OSTI)

A new hybrid composite (APAL; Aramid Patched Aluminum Alloy), consisting of 2024-T3 aluminum alloy plate sandwiched between aramid/epoxy prepregs (HK 285/RS 1222), was developed. Fatigue crack growth behavior was examined at stress ratios of R = 0.2, 0.5 using two kinds of APAL with different fiber orientation (0{degree}/90{degree} and {+-} 45{degree} for crack direction). The APAL showed superior fatigue crack growth resistance, which may be attributed to the crack bridging effect imposed by the intact fibers in the crack wave. The magnitude of crack bridging was estimated quantitatively and determined by a new technique on the basis of the compliances of 2024-T3 aluminum alloy and APAL specimens. The crack growth rate of the APAL specimens was reduced significantly as comparison to the monolithic aluminum alloy and was not adequately correlated with the conventional stress intensity factor range ({Delta}K). It was found that the crack growth rate was successfully correlated with the effective stress intensity factor range ( {Delta}K{sub eff} = K{sub br} {minus} K{sub cl}) allowing for the crack closure and the crack bridging. The relation between da/dN and {Delta}K{sub eff} was plotted within a narrow scatter band regardless at loading line of 2024-T3 aluminum alloy, two kinds of the APAL (APAL 0{degree}/90{degree}, APAL {+-} 45{degree}) and two kinds of stress ratios (R = 0.2, 0.5).

Oh, S.W.; Park, W.J. [Dong-A Univ., Pusan (Korea, Republic of). Dept. of Mechanical Engineering; Yoon, H.K.; Lee, K.G. [Dong-Eui Univ., Pusan (Korea, Republic of). Dept. of Mechanical Engineering; Cho, J.M.; Lee, K.B. [Han Kuk Fiber Glass Co. Ltd., Kyungnam (Korea, Republic of)

1993-12-31T23:59:59.000Z

368

Finite element analysis of a crack tip in silicate glass: No evidence for a plastic zone  

Science Journals Connector (OSTI)

Recently, the claim was made that cracks in silicate glasses propagate by the nucleation, growth, and coalescence of cavities at crack tips, which is the same way as in metals but at a much smaller scale. This hypothesis for crack growth is based in part on the measurement of surface displacements near the tip of an emerging crack, which is the point at which a crack front intersects the side surface of the specimen. Surface displacements measured by atomic force microscopy were less than theoretically predicted. The difference between the theoretical and experimental displacements was attributed to a plastic zone surrounding the tip of the moving crack. In this paper, we show that the theoretical analysis used earlier was based on an incorrect assumption about the functional dependence of the displacement with distance from the crack tip. We use a full three-dimensional finite element analysis combined with an asymptotic solution of the crack geometry to obtain a solution to the surface displacement problem. We show that the calculated displacements are fully consistent with those experimentally measured by using an atomic force microscope. No divergence from elastic behavior is observed. Our results support the view that crack propagation in glass is entirely brittle. No evidence for plasticity at the crack tips is obtained.

T. Fett, G. Rizzi, D. Creek, S. Wagner, J. P. Guin, J. M. López-Cepero, and S. M. Wiederhorn

2008-05-15T23:59:59.000Z

369

Acoustic Emission Detection and Prediction of Fatigue Crack Propagation in Composite Patch Repairs Using Neural Networks  

SciTech Connect (OSTI)

An aircraft is subjected to severe structural and aerodynamic loads during its service life. These loads can cause damage or weakening of the structure especially for aging military and civilian aircraft, thereby affecting its load carrying capabilities. Hence composite patch repairs are increasingly used to repair damaged aircraft metallic structures to restore its structural efficiency. This paper presents the results of Acoustic Emission (AE) monitoring of crack propagation in 2024-T3 Clad aluminum panels repaired with adhesively bonded octagonal, single sided boron/epoxy composite patch under tension-tension fatigue loading. Crack propagation gages were used to monitor crack initiation. The identified AE sensor features were used to train neural networks for predicting crack length. The results show that AE events are correlated with crack propagation. AE system was able to detect crack propagation even at high noise condition of 10 Hz loading; that crack propagation signals can be differentiated from matrix cracking signals that take place due to fiber breakage in the composite patch. Three back-propagation cascade feed forward networks were trained to predict crack length based on the number of fatigue cycles, AE event number, and both the Fatigue Cycles and AE events, as inputs respectively. Network using both fatigue cycles and AE event number as inputs to predict crack length gave the best results, followed by Network with fatigue cycles as input, while network with just AE events as input had a greater error.

Okafor, A. Chukwujekwu; Singh, Navdeep; Singh, Navrag [Structural Health Monitoring and NDE Laboratory, Department of Mechanical and Aerospace Engineering, University of Missouri-Rolla, 1870 Miner Circle Rolla MO 65409-0050 (United States)

2007-03-21T23:59:59.000Z

370

Stress Corrosion Cracking and Non-Destructive Examination of Dissimilar Metal Welds and Alloy 600  

SciTech Connect (OSTI)

The United States Nuclear Regulatory Commission (USNRC) has conducted research since 1977 in the areas of environmentally assisted cracking and assessment and reliability of non-destructive examination (NDE). Recent occurrences of cracking in Alloy 82/182 welds and Alloy 600 base metal at several domestic and overseas plants have raised several issues relating to both of these areas of NRC research. The occurrences of cracking were identified by the discovery of boric acid deposits resulting from through-wall cracking in the primary system pressure boundary. Analyses indicate that the cracking has occurred due to primary water stress corrosion cracking (PWSCC) in Alloy 82/182 welds. This cracking has occurred in two different locations: in hot leg nozzle-to-safe end welds and in control rod drive mechanism (CRDM) nozzle welds. The cracking associated with safe-end welds is important due to the potential for a large loss of reactor coolant inventory, and the cracking of CRDM nozzle base metal and welds, particularly circumferential cracking of CRDM nozzle base metal, is important due to the potential for a control rod to eject resulting in a loss of coolant accident. The industry response in the U.S. to this cracking is being coordinated through the Electric Power Research Institute's Materials Reliability Project (EPRI-MRP) in a comprehensive, multifaceted effort. Although the industry program is addressing many of the issues raised by these cracking occurrences, confirmatory research is necessary for the staff to evaluate the work conducted by industry groups. Several issues requiring additional consideration regarding the generic implications of these isolated events have been identified. This paper will discuss the recent events of significant cracking in domestic and foreign plants, discuss the limitations of NDE in detecting SCC, identify deficiencies in information available in this area, discuss the USNRC approach to address these issues, and discuss the development of an international cooperative effort. (authors)

Jackson, Deborah A. [U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001 (United States)

2002-07-01T23:59:59.000Z

371

The Thermal Expansion, Elastic and Fracture Properties of Porous Cordierite at Elevated Temperatures  

SciTech Connect (OSTI)

The properties that determine the thermal shock resistance in materials are reported for porous cordierite, a leading candidate material for the fabrication of diesel particulate filters. Fracture toughness and slow crack growth tests were performed on test specimens obtained from the walls of diesel particulate filter monolithic substrates using the double-torsion test method at temperatures between 20 C and 900 C. The thermal expansion and elastic properties were characterized between 20 C and 1000 C. The role of the microstructure of porous cordierite in determining its unusual thermal expansion and elevated temperature Young's modulus and fracture toughness are discussed.

Shyam, Amit [ORNL; Lara-Curzio, Edgar [ORNL; Pandey, Amit [ORNL; Watkins, Thomas R [ORNL; More, Karren [Oak Ridge National Laboratory (ORNL)

2012-01-01T23:59:59.000Z

372

Catalytic destruction of groundwater contaminants in reactive extraction wells  

DOE Patents [OSTI]

A system for remediating groundwater contaminated with halogenated solvents, certain metals and other inorganic species based on catalytic reduction reactions within reactive well bores. The groundwater treatment uses dissolved hydrogen as a reducing agent in the presence of a metal catalyst, such a palladium, to reduce halogenated solvents (as well as other substituted organic compounds) to harmless species (e.g., ethane or methane) and immobilize certain metals to low valence states. The reactive wells function by removing water from a contaminated water-bearing zone, treating contaminants with a well bore using catalytic reduction, and then reinjecting the treated effluent into an adjacent water-bearing zone. This system offers the advantages of a compact design with a minimal surface footprint (surface facilities) and the destruction of a broad suite of contaminants without generating secondary waste streams.

McNab, Jr., Walt W. (Concord, CA); Reinhard, Martin (Stanford, CA)

2002-01-01T23:59:59.000Z

373

Catalytic production of metal carbonyls from metal oxides  

DOE Patents [OSTI]

This invention relates to the formation of metal carbonyls from metal oxides and specially the formation of molybdenum carbonyl and iron carbonyl from their respective oxides. Copper is used here in admixed form or used in chemically combined form as copper molybdate. The copper/metal oxide combination or combined copper is utilized with a solvent, such as toluene and subjected to carbon monoxide pressure of 25 atmospheres or greater at about 150 to 260/sup 0/C. The reducing metal copper is employed in catalytic concentrations or combined concentrations as CuMoO/sub 4/ and both hydrogen and water present serve as promoters. It has been found that the yields by this process have been salutary and that additionally the catalytic metal may be reused in the process to good effect. 3 tables.

Sapienza, R.S.; Slegeir, W.A.; Foran, M.T.

1984-01-06T23:59:59.000Z

374

The Role of Carbon in Catalytically Stabilized Transition Metal Sulfides  

SciTech Connect (OSTI)

Since WWII considerable progress has been made in understanding the basis for the activity and the selectivity of molybdenum and tungsten based hydrotreating catalysts. Recently, the focus of investigation has turned to the structure of the catalytically stabilized active catalyst. The surface of the catalytically stabilized MoS2 has been shown to be carbided with the formula MoSxCy under hydrotreating conditions. In this paper we review the basis for this finding and present new data extending the concept to the promoted TMS (transition metal sulfides) systems CoMoC and NiMoC. Freshly sulfided CoMoS and NiMoS catalyst have a strong tendency to form the carbided surface phases from any available carbon source.

Kelty,S.; Berhault, G.; Chianelli, R.

2007-01-01T23:59:59.000Z

375

Seasonal thermal energy storage  

SciTech Connect (OSTI)

This report describes the following: (1) the US Department of Energy Seasonal Thermal Energy Storage Program, (2) aquifer thermal energy storage technology, (3) alternative STES technology, (4) foreign studies in seasonal thermal energy storage, and (5) economic assessment.

Allen, R.D.; Kannberg, L.D.; Raymond, J.R.

1984-05-01T23:59:59.000Z

376

Catalytic Hydrothermal Conversion of Triglycerides to Non-ester Biofuels  

Science Journals Connector (OSTI)

Catalytic Hydrothermal Conversion of Triglycerides to Non-ester Biofuels ... Results derived from soybean oil, jatropha oil, and tung oil show that certain biofuel fractions met JP-8 specifications and Navy distillate specifications. ... Therefore, tung-oil-derived CH biofuel will have added value as a blend stock for existing FT jet fuels and emerging biofuels such as those produced from the UOP/ENI EcofiningTM process to meet fuel specifications by increasing density and aromatic content. ...

Lixiong Li; Edward Coppola; Jeffrey Rine; Jonathan L. Miller; Devin Walker

2010-01-13T23:59:59.000Z

377

Micro-Scale Catalytic Reactor for Syngas Production  

Science Journals Connector (OSTI)

Micro-Scale Catalytic Reactor for Syngas Production ... The H2 yield (?H2) was evaluated as moles of H2 produced per mole of CH4 converted in the reforming channel. ... In particular, the maximum temperature moves from a location close to the reactor center (for MCH4-sr/MCH4-co = 2) toward the reactor inlet producing in the case of MCH4-sr/MCH4-co =2.75 decreasing temperature profiles without a maximum. ...

S. Vaccaro; L. Malangone; P. Ciambelli

2010-07-01T23:59:59.000Z

378

Catalytic Graphitization of Carbon Aerogels by Transition Metals  

Science Journals Connector (OSTI)

Catalytic Graphitization of Carbon Aerogels by Transition Metals ... Carbon aerogels and Cr-, Fe-, Co-, and Ni-containing carbon aerogels were obtained by pyrolysis, at temperatures between 500 and 1800 °C, of the corresponding aerogels prepared by the sol?gel method from polymerization of resorcinol with formaldehyde. ... Results obtained show that carbon aerogels are, essentially, macroporous materials that maintain large pore volumes even after pyrolysis at 1800 °C. ...

F. J. Maldonado-Hódar; C. Moreno-Castilla; J. Rivera-Utrilla; Y. Hanzawa; Y. Yamada

2000-03-24T23:59:59.000Z

379

Thermal unobtainiums? The perfect thermal conductor and  

E-Print Network [OSTI]

contribute to thermal resistance · Isotopically pure diamond has highest thermal conductivity of any material materials: disordered layered crystals Conclude with some thoughts on promising, high-risk, research even in a computer model. #12;Thermal resistance is created by Umklapp scattering (U

Braun, Paul

380

Thermal Control & System Integration  

Broader source: Energy.gov [DOE]

The thermal control and system integration activity focuses on issues such as the integration of motor and power control technologies and the development of advanced thermal control technologies....

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


381

Significance of crack opening monitoring for determining the growth behavior of hydrofractures  

SciTech Connect (OSTI)

A method for determining the size of a crack induced by hydraulic fracturing is presented. The procedure is based on the measurement of the crack opening displacement and the fracture mechanics approach. The proposed method has been tested by conducting laboratory small-scale hydraulic fracturing tests on a granite. It is shown from the preliminary tests that the method provides a reasonable prediction of experimentally observed crack sizes.

Hashida, Toshiyuki; Sato, Kazushi; Takahashi, Hideaki

1993-01-28T23:59:59.000Z

382

Regenerative thermal oxidation and alternative technologies for VOC control  

SciTech Connect (OSTI)

Thermal oxidation technologies have been used successfully to control VOC`s for many years but the recent 1990 Clean Air Act Amendments have spurred improvements in the established processes and development of economic alternatives. The combination of the regulatory maze and confusion in the selection of the best technology for a particular application has created a potential nightmare for those companies facing a need to reduce their VOC EMISSIONS. The relative advantages and disadvantages of regenerative, recuperative and catalytic oxidizers will be reviewed, with an emphasis on the economic justification for regenerative thermal oxidation (RTO). Control efficiencies of more than 99% have been demonstrated for RTO`s on a multitude of industrial process exhaust streams. Lowest evaluated cost over a fifteen to twenty year effective equipment life is a key selection criteria. This paper describes the underlying principles of thermal oxidation, and discusses the applicability of these and other emerging technologies for VOC control.

Biedell, E.L. [REECQ, Somerville, NJ (United States)

1995-12-31T23:59:59.000Z

383

Stress-corrosion cracking of steels in ammonia with consideration given to OTEC design: a survey  

SciTech Connect (OSTI)

Carbon steel, alloy steel, and high-strength, quenched and tempered steel, when under applied or residual stress and especially when cold formed and/or welded without subsequent thermal stress relief, are subject to failure by stress-corrosion cracking (SCC) in air-contaminated dry ammonia. Water as well as hydrazine when present in small amounts have been shown to be effective inhibitors in an all steel system. Galvanic corrosion between dissimilar metals and/or accelerated failure by SCC of stressed steel as a result of galvanic coupling may be of concern. Where water has proven effective as an inhibitor of SCC in an all steel system, it may not be adequate in a mixed metal system. With aluminum tubes, the tube sheet will either have to be solid aluminum, aluminum clad steel or some nonconductive coating will be necessary to effectively remove the cathodic alloy from the galvanic circuit. Research is required to determine the severity of the coupling effect between dissimilar alloys in ammonia under OTEC conditions; especially the possibility of accelerated SCC failures of stressed steel where the presence of an inhibitor in the ammonia may not be sufficient to override the galvanic coupling effect.

Teel, R.B.

1980-03-01T23:59:59.000Z

384

Evaluation of low-cycle fatigue crack growth and subsequent ductile fracture for cracked pipe experiments using cyclic J-integral  

SciTech Connect (OSTI)

Piping for LWR power plants is required to satisfy the Leak-Before-Break concept for postulated (not actual) defects. With this in mind, numerous research has so far been conducted on the fatigue crack growth under cyclic loading, and on the ductile crack growth under excessive loading. Study on cracked pipe fracture under cyclic loading gains much attention from the viewpoint of the Leak-Before-Break concept for seismic loading that accompanies large-scale yielding. An evaluation method based on cyclic J-integral was newly developed to predict the low-cycle fatigue crack growth and the subsequent ductile fracture for cyclic loading that accompanies large-scale yielding. Cyclic J-integral was introduced to describe the crack growth up to failure. The method was applied to 4-inch diameter circumferentially through-wall-cracked carbon steel base metal pipes and welded pipe joints subjected to cyclic 4-point bending at room temperature and high temperature of approximately 300 C. Fatigue crack growth behavior and failure life were successfully predicted by the proposed approach.

Miura, Naoki; Fujioka, Terutaka; Kashima, Koichi [CRIEPI, Tokyo (Japan); Miyazaki, Katsumasa; Kanno, Satoshi; Hayashi, Makoto; Ishiwata, Masayuki; Gotoh, Nobuho [Hitachi, Ltd., Ibaraki (Japan)

1996-12-01T23:59:59.000Z

385

Solar reforming of methane in a direct absorption catalytic reactor on a parabolic dish: 2, Modeling and analysis  

SciTech Connect (OSTI)

The CAtalytically Enhanced Solar Absorption Receiver (CAESAR) experiment was conducted to determine the thermal, chemical, and mechanical performance of a commercial-scale, dish-mounted, direct catalytic absorption receiver (DCAR) reactor over a range of steady state and transient (cloud) operating conditions. The focus of the experiment is on global performance such as receiver efficiencies and overall methane conversion; it was not intended to provide data for code validation. A numerical model was previously developed to provide guidance in the design of the absorber. The one-dimensional, planar and steady-state model incorporates, the following energy transfer mechanisms: solar and infrared radiation, heterogeneous chemical reaction, conduction in the solid phase, and convection between the fluid and solid phases. A number of upgrades to the model and improved property values are presented here. Model predictions are shown to bound the experimental axial thermocouple data when experimental uncertainties are included. Global predictions are made using a technique in which the incident solar flux distribution is subdivided into flux contour bands. Model predictions for each band are then spatially integrated to provide global predictions such as reactor efficiencies and methane conversions. Global predictions are shown to compare well with experimental data. Reactor predictions for anticipated operating conditions suggest a further decrease in optical density at the front of the absorber inner disk may be beneficial. The need to conduct code-validation experiments is identified as essential to improve the confidence in the capability to predict large-scale reactor operation.

Skocypec, R.D.; Hogan, R.E. Jr.; Muir, J.F.

1991-01-01T23:59:59.000Z

386

E-Print Network 3.0 - assisted fatigue crack Sample Search Results  

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

and Grain-Boundary Adhesion Summary: unless they experience environmentally assisted subcritical growth during cyclic loading.7 Fatigue-crack... (moist air and dry N2). The...

387

Modeling of interaction between corrosion-induced concrete cover crack and steel corrosion rate.  

E-Print Network [OSTI]

??Chloride-induced corrosion of steel reinforcement in concrete may cause severe damage to RC structures. Longitudinal cover cracks may form during the rust expansion process. Currently,… (more)

Cao, Chong

2012-01-01T23:59:59.000Z

388

Low Alloy Steel Susceptibility to Stress Corrosion Cracking in Hydraulic Fracturing Environment.  

E-Print Network [OSTI]

??The pipelines used for hydraulic fracturing (aka. "fracking") are often operating at a pressure above 10000psi and thus are highly susceptible to Stress Corrosion Cracking… (more)

Anyanwu, Ezechukwu John

2014-01-01T23:59:59.000Z

389

Simulation of the ultrasonic array response from real branched cracks using an efficient finite element method  

SciTech Connect (OSTI)

A hybrid model to simulate the ultrasonic array response from stress corrosion cracks is presented. These cracks are branched and difficult to detect so the model is required to enable optimization of an array design. An efficient frequency-domain finite element method is described and selected to simulate the ultrasonic scattering. Experimental validation results are presented, followed by an example of the simulated ultrasonic array response from a real stress corrosion crack whose geometry is obtained from an X-ray Computed Tomography image. A simulation-assisted array design methodology, which includes the model and use of real crack geometries, is proposed.

Felice, Maria V. [Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR, United Kingdom and Rolls-Royce plc., Bristol BS34 7QE (United Kingdom); Velichko, Alexander; Wilcox, Paul D. [Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR (United Kingdom); Barden, Tim J.; Dunhill, Tony K. [Rolls-Royce plc., Bristol BS34 7QE (United Kingdom)

2014-02-18T23:59:59.000Z

390

Subcritical crack growth, initiation, and arrest in columnar freshwater and sea ice.  

E-Print Network [OSTI]

??A study was conducted to determine if slow stable sub-critical crack growth may occur in ice. The Double Torsion fracture toughness geometry was used to… (more)

Parsons, Bruce L.

1989-01-01T23:59:59.000Z

391

Welding Hot Cracking of Side Shell of Drilling-Well Oil Storage Ship  

Science Journals Connector (OSTI)

...Cracks were found in the weld metal (WM) of weld-section of side shell of drilling-well oil storage ship when performing post weld radiographic...

Zhi-wei Yu; Xiao-lei Xu

2014-11-01T23:59:59.000Z

392

Fracture of Hydrided Zircaloy-4 Sheet under Through-Thickness Crack Growth Conditions  

SciTech Connect (OSTI)

The failure of thin-wall components such as fuel cladding may be caused by crack initiation on the component surface and subsequent crack growth through its thickness. This study has determined the fracture toughness of hydrided cold-worked stress relieved Zircaloy-4 sheet subject to through-thickness crack growth at 25 deg. C. The experimental approach utilizes a novel procedure in which a narrow linear strip of brittle hydride blister across the specimen width creates a well-defined pre-crack upon initial loading. The subsequent crack growth resistance is then characterized by four-point bending of the specimen and an elastic-plastic fracture mechanics analysis. At room temperature, the through-thickness fracture toughness (K{sub Q}) is sensitive to the orientation of the hydride platelets, and K{sub Q} {approx_equal} 25 MPavm for crack growth through a mixed in-plane/out-of-plane hydride field. In contrast, K{sub Q} is much higher ({approx_equal} 75 MPavm) when the hydride platelets are oriented predominantly in the plane of the sheet (and therefore normal to both the crack plane and the crack growth direction). The implication of these fracture toughness values to the fracture strain behavior of hydrided Zircaloy-4 under through-thickness crack growth conditions is illustrated. (authors)

Raynaud, P.A.; Koss, D.A. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Motta, A.T. [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Chan, K.S. [Southwest Research Institute, San Antonio, TX 78238 (United States)

2007-07-01T23:59:59.000Z

393

Innovative Approach to Establish Root Causes for Cracking in Aggressive Reactor Environments  

SciTech Connect (OSTI)

The research focuses on the high-resolution characterization of degradation microstructures and microchemistries in specimens tested under controlled conditions for the environment and for the material where in-service complexities can be minimized. Thermodynamic and kinetic modeling of crack-tip processes is employed to analyze corrosion-induced structures and gain insights into degradation mechanisms. Novel mechanistic ''fingerprinting'' of crack-tip structures is used to isolate causes of environmental cracking in tandem with quantitative measurements of crack growth. Sample preparation methods and advanced analytical techniques are used to characterize corrosion/oxidation reactions and crack-tip structures at near atomic dimensions in order to gain insight into fundamental environmental cracking mechanisms. Reactions at buried interfaces, not accessible by conventional approaches, are being systematically interrogated. Crack-growth experiments in high-temperature water environments are evaluating and isolating the effects of material condition (matrix strength, grain boundary composition and precipitation) on stress corrosion cracking (SCC). The fundamental understanding of crack advance mechanisms will establish the basis to design new corrosion-resistant alloys for current light-water reactors and advanced reactor systems.

Bruemmer, Stephen M.; Thomas, Larry E.; Vetrano, John S.; Simonen, Edward P.

2003-10-31T23:59:59.000Z

394

Temperature and environmentally assisted cracking in low alloy steel  

SciTech Connect (OSTI)

Environmental assisted cracking (EAC) can be defined as the propagation of fatigue cracks in water at rates from 3 to over 40 times the growth rates in air. For low alloy steels with sulfur contents > 0.0125% by weight, EAC is normal behavior in the 240 to 290C range. However, literature yields mixed results for low alloy steels with compositions just below this sulfur level; some reports indicate EAC while others do not. Also, several authors have reported an increased tendency toward EAC when the water temperatures were lowered. In the present work, five ASTM A 508 Class 2 forgings with ladle and check analyses that ranged from 0.010 to 0.019 wt% S were tested in high purity deaerated water in the temperature range of 93 to 260C. At 260C these forgings did not exhibit EAC, reinforcing earlier results for two similar forgings. This broad sampling indicates strong resistance to EAC for this class of forging at 260C. On the other hand, EAC occurred consistently in the three of these forgings that were tested below 204C, provided the test conditions (loading frequency, {Delta}K, and R) were high enough to produce a high baseline fatigue crack growth rate (FCGR), where the baseline FCGR is that expected in air. At 149C, EAC occurred at test conditions that combined to yield a baseline FCGR greater than {approx}2E-6 mm/s. At 204, 121, and 93C, this critical crack growth rate appeared to shift to lower baseline values. The EAC that occurred at lower temperatures was a factor of 3 to 12 times higher than baseline air rates, which was not as strong as the effect for higher sulfur steels at 240 to 290C. Also, no plateau in the growth rates occurred as it does with the higher sulfur steels. In another approach, EAC was induced at 93 and at 260C by raising the dissolved oxygen content of the water from <10 to >15 ppb.

Auten, T.A.; Monter, J.V.

1995-04-01T23:59:59.000Z

395

Physics-Based Stress Corrosion Cracking Component Reliability  

Broader source: Energy.gov (indexed) [DOE]

Physics-Based Stress Corrosion Physics-Based Stress Corrosion Cracking Component Reliability Model cast in an R7-Compatible Cumulative Damage Framework Draft Report Supporting Technology Inputs to the Risk- Informed Safety Margin Characterization Pathway of the DOE Light Water Reactor Sustainability Program Stephen D. Unwin Kenneth I. Johnson Robert F. Layton Peter P. Lowry Scott E. Sanborn Mychailo B. Toloczko PNNL-20596 July 2011 Physics-Based SCC Reliability Model in a Cumulative Damage Framework 2 Physics-Based SCC Reliability Model in a Cumulative Damage Framework 3 Table of Contents Executive Summary............................................................................... 4 1. Introduction .......................................................................... 5

396

Influence of the conditions of preparation on the catalytic properties of A1-pillared montmorillonites  

SciTech Connect (OSTI)

Pillared clays (PILC) are obtained by exchanging the original cations of a smectite by inorganic cationic polymers. The size of the pillaring species determines the porosity of the resulting material. Pore openings of 8-17 {angstrom} can me obtained with many cations, including A1, Zr, Cr, and Ti. The interest in PILC was heightened by the report that they are more active than Y zeolites for bulky molecules. Indeed, Lussier et al. observed good activity for cracking of heavy gas oil. Clays produced less gasoline than zeolites, but the octane number was higher. Occelli reports a gasoline yield comparable to that of zeolites using a lighter charge stock. The high selectivity for coke was attributed to iron impurities by Lussier et al., but Occelli found no influence of the iron content of the clay on the coke make. The thermal stability is apparently controlled by small details of the preparation, since clear differences appear between A1-PILC or Zr-PILC, according to the authors. We present here a synthesis concerning our work on preparation, characterization and testing of montmorillonites pillared by A1{sub 13} polymers, including the influence of particle size of the original clay on the properties of the resulting PILC.

Tichit, D.; Fajula, F.; Figueras, F.; Gueguen, C.; Bousquet, J. (CNRS ENSCM, Montpellier (France))

1987-08-01T23:59:59.000Z

397

Method and apparatus for monitoring a hydrocarbon-selective catalytic reduction device  

DOE Patents [OSTI]

A method for monitoring a hydrocarbon-selective catalytic reactor device of an exhaust aftertreatment system of an internal combustion engine operating lean of stoichiometry includes injecting a reductant into an exhaust gas feedstream upstream of the hydrocarbon-selective catalytic reactor device at a predetermined mass flowrate of the reductant, and determining a space velocity associated with a predetermined forward portion of the hydrocarbon-selective catalytic reactor device. When the space velocity exceeds a predetermined threshold space velocity, a temperature differential across the predetermined forward portion of the hydrocarbon-selective catalytic reactor device is determined, and a threshold temperature as a function of the space velocity and the mass flowrate of the reductant is determined. If the temperature differential across the predetermined forward portion of the hydrocarbon-selective catalytic reactor device is below the threshold temperature, operation of the engine is controlled to regenerate the hydrocarbon-selective catalytic reactor device.

Schmieg, Steven J; Viola, Michael B; Cheng, Shi-Wai S; Mulawa, Patricia A; Hilden, David L; Sloane, Thompson M; Lee, Jong H

2014-05-06T23:59:59.000Z

398

Thermal Management of Solar Cells  

E-Print Network [OSTI]

a better thermal conductance and when ceramic particles areor ceramic fillers that enhances thermal conductivity. Solid

Saadah, Mohammed Ahmed

2013-01-01T23:59:59.000Z

399

Influence of complexation processes on the catalytic properties of some polymer-based cobalt compounds for oxygen electroreduction  

SciTech Connect (OSTI)

Electrochemical and X-ray absorption techniques have been used to determine the influence of complexation processes on the catalytic properties of heat-treated systems composed by the mixture of one polymer and Co acetate. Three non-nitrogenous polymers were studied: poly(methyl vinyl ketone) (PVK), poly(acrylic acid) (PAA); and polystyrene (PE). The catalysts composed by PE and PAA presented very low activity for the O{sub 2} reduction; a maximum of activity was found for the PVK catalyst at 100{degree}C. XAFS experiments at the Co, N, C, and O K edges showed that complexation between Co ions and the polymer yields a good dispersion of the Co ions and formation of small Co clusters during the thermal treatment. The absence of complexation leads to very poor activity, as in the case of PE and PAA. 14 refs., 13 figs., 5 tabs.

Alves, M.C.M.; Tourillon, G. [LURE, Orsay (France)

1996-05-02T23:59:59.000Z

400

INVESTIGATION OF AMMONIA ADSORPTION ON FLY ASH DUE TO INSTALLATION OF SELECTIVE CATALYTIC REDUCTION SYSTEMS  

SciTech Connect (OSTI)

This report summarizes an investigation of the potential impacts associated with the utilization of selective catalytic reduction (SCR) systems at coal-fired power plants. The study was sponsored by the U.S. Department of Energy Emission Control By-Products Consortium, Dominion Generation, the University of Kentucky Center for Applied Energy Research and GAI Consultants, Inc. SCR systems are effective in reducing nitrogen oxides (NOx) emissions as required by the Clean Air Act (CAA) Amendments. However, there may be potential consequences associated with ammonia contamination of stack emissions and combustion by-products from these systems. Costs for air quality, landfill and pond environmental compliance may increase significantly and the marketability of ash may be seriously reduced, which, in turn, may also lead to increased disposal costs. The potential impacts to air, surface water, groundwater, ash disposal, ash utilization, health and safety, and environmental compliance can not be easily quantified based on the information presently available. The investigation included: (1) a review of information and data available from published and unpublished sources; (2) baseline ash characterization testing of ash samples produced from several central Appalachian high-volatile bituminous coals from plants that do not currently employ SCR systems in order to characterize the ash prior to ammonia exposure; (3) an investigation of ammonia release from fly ash, including leaching and thermal studies; and (4) an evaluation of the potential impacts on plant equipment, air quality, water quality, ash disposal operations, and ash marketing.

G.F. Brendel; J.E. Bonetti; R.F. Rathbone; R.N. Frey Jr.

2000-11-01T23:59:59.000Z

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


401

Treatment of \\{VOCs\\} with molecular sieve catalysts in regenerative catalytic oxidizer  

Science Journals Connector (OSTI)

This work prepares molecular sieve catalysts with various metal species and various metal weight loadings by impregnation, and then screens them in a catalytic combustion system. The current study further investigates the molecular sieve catalyst in an RCO system after it performed well in combustion efficiency. This work tests its performances in terms of CO2 yield, pressure drop, the difference between temperatures of the inlet and outlet gases (Td), and thermal recovery efficiency (TRE), with various operational conditions. Experimental results demonstrate that the 10 wt% Cu/(MS) catalyst was the most active because it has the greatest combustion efficiency to treat volatile organic compounds (VOCs) than Co/(MS) catalysts and Mn/(MS) catalysts. The 10 wt% Cu/(MS) catalyst used in an RCO system reaches over 95% CO2 yields under the heating zone temperature (Tset) = 400 °C, gas velocity (Ug) = 0.37 m/s, isopropyl alcohol (IPA) concentration = 200–400 ppm conditions. Moreover, the RCO system performed well in economic efficiency with the RCO with in terms of TRE, Td and pressure drop. The TRE ranged from 90.4% to 94.6% and Td ranged from 14.0 to 34.2 °C under various conditions at Tset = 300–450 °C. Finally, the results of the stability test demonstrated that the catalyst was very stable at various Ug values and various Tset values.

Shih-Wei Huang; Jie-Chung Lou; Yung-Chang Lin

2010-01-01T23:59:59.000Z

402

Studies on the thermal inactivation of immobilized enzymes  

SciTech Connect (OSTI)

The thermal inactivation of a great number of immobilized enzymes shows a biphasic kinetics, which distinctly differs from the first-order inactivation kinetics of the corresponding soluble enzymes. As shown for ..cap alpha..-amylase, chymotrypsin, and trypsin covalently bound to silica, polystyrene, or polyacrylamide, the dependence of the remaining activities on the heating time can be well described by the sum of two exponential terms. To interpret this mathematical model function, the catalytic properties of immobilized enzymes (number of active sites in silica-bound trypsin, Km and Ea values in silica-bound ..cap alpha..-amylase and chymotrypsin) at different stages of inactivation and the influence of various factors (coupling conditions, addition of denaturants or stabilizers, etc.) on the thermal inactivation of silica-bound ..cap alpha..-amylase were studied. Furthermore, conformational alterations in the thermal denaturation of spin-labeled soluble and silica-bound ..beta..-amylase were compared by electron spin resonance (ESR) studies. The results suggest that the biphasic inactivation kinetics reflects two different pathways according to which catalytically identical enzyme molecules are predominantly inactivated. 45 references.

Ulbrich, R.; Schellenberger, A.; Damerau, W.

1986-04-01T23:59:59.000Z

403

Prediction of PWSCC in nickel base alloys using crack growth rate models  

SciTech Connect (OSTI)

The Ford/Andresen slip-dissolution SCC model, originally developed for stainless steel components in BWR environments, has been applied to Alloy 600 and Alloy X-750 tested in deaerated pure water chemistry. A method is described whereby the crack growth rates measured in compact tension specimens can be used to estimate crack growth in a component. Good agreement was found between model prediction and measured SCC in X-750 threaded fasteners over a wide range of temperatures, stresses, and material conditions. Most data support the basic assumption of this model that cracks initiate early in life. The evidence supporting a particular SCC mechanism is mixed. Electrochemical repassivation data and estimates of oxide fracture strain indicate that the slip-dissolution model can account for the observed crack growth rates, provided primary rather than secondary creep rates are used. However, approximately 100 cross-sectional TEM foils of SCC cracks including crack tips reveal no evidence of enhanced plasticity or unique dislocation patterns at the crack tip or along the crack to support a classic slip-dissolution mechanism. No voids, hydrides, or microcracks are found in the vicinity of the crack tips creating doubt about classic hydrogen related mechanisms. The bulk oxide films exhibit a surface oxide which is often different than the oxides found within a crack. Although bulk chromium concentration affects the rate of SCC, analytical data indicates the mechanism does not result from chromium depletion at the grain boundaries. The overall findings support a corrosion/dissolution mechanism but not one necessarily related to slip at the crack tip.

Thompson, C.D.; Krasodomski, H.T.; Lewis, N.; Makar, G.L. [Knolls Atomic Power Lab., Schenectady, NY (United States)

1995-12-31T23:59:59.000Z

404

Pulping black liquor used directly as a green and effective source for neat oil and as an emulsifier of catalytic cracking heavy oil  

Science Journals Connector (OSTI)

The objective of this study is to evaluate the use of emulsified heavy oils to conduct the FCC reaction. The emulsified heavy oil was prepared by homogenizing. Properties of emulsified heavy oil, including int...

Ge Xu; Ji-he Yang; Hui-hui Mao; Zhi Yun

2011-09-01T23:59:59.000Z

405

Bioenergy Technologies Office R&D Pathways: Ex-Situ Catalytic Fast Pyrolysis  

Broader source: Energy.gov [DOE]

In ex-situ catalytic fast pyrolysis, biomass is heated with catalysts to create bio-oils, which are then used to produce biofuel blendstocks.

406

E-Print Network 3.0 - automobile catalytic converters Sample...  

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

Search Powered by Explorit Topic List Advanced Search Sample search results for: automobile catalytic converters Page: << < 1 2 3 4 5 > >> 1 IEEE International Symposium on...

407

Catalytic ozonation of phenol in water with natural brucite and magnesia  

Science Journals Connector (OSTI)

Natural brucite and magnesia were applied as catalysts in catalytic ozonation of phenol in this work. It was found that both brucite and magnesia had remarkable accelerations on degradation of phenol and removal of COD in water. On this basis, effective and feasible routes for catalytic ozonation of phenol in water were proposed. The influence of initial pH value, radical scavengers and reaction temperature were investigated. The results revealed that there were different ozonation mechanisms in two systems: molecular ozone direct oxidation mechanism was proved in catalytic ozonation with brucite, and hydroxyl radical mechanism was demonstrated to play a main role in catalytic ozonation with magnesia.

Kun He; Yu Ming Dong; Zhen Li; Lin Yin; Ai Min Zhang; Yi Chun Zheng

2008-01-01T23:59:59.000Z

408

Catalytic microwave torrefaction and pyrolysis of Douglas fir pellet to improve biofuel quality .  

E-Print Network [OSTI]

??The aims of this dissertation were to understand the effects of torrefaction as pretreatment on biomass pyrolysis and catalytic pyrolysis for improving biofuel quality, and… (more)

[No author

2012-01-01T23:59:59.000Z

409

E-Print Network 3.0 - apparent catalytic site Sample Search Results  

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

Yeshiva University Collection: Materials Science 11 Chemo-Mechanical Coupling in F1-ATPase Revealed by Catalytic Site Occupancy during Catalysis Summary: Chemo-Mechanical...

410

Solid state oxygen anion and electron mediating membrane and catalytic membrane reactors containing them  

DOE Patents [OSTI]

A process for production of synthesis gas employing a catalytic membrane reactor wherein the membrane comprises a mixed metal oxide material.

Schwartz, Michael (Boulder, CO); White, James H. (Boulder, CO); Sammells, Anthony F. (Boulder, CO)

2001-01-01T23:59:59.000Z

411

Atomic Hydrogen in Condensed Form Produced by a Catalytic Process:? A Future Energy-Rich Fuel?  

Science Journals Connector (OSTI)

Atomic Hydrogen in Condensed Form Produced by a Catalytic Process:? A Future Energy-Rich Fuel? ... Energy Fuels, 2005, 19 (6), ...

Shahriar Badiei; Leif Holmlid

2005-10-04T23:59:59.000Z

412

Problems in Catalytic Oxidation of Hydrocarbons and Detailed Simulation of Combustion Processes.  

E-Print Network [OSTI]

??This dissertation research consists of two parts, with Part I on the kinetics of catalytic oxidation of hydrocarbons and Part II on aspects on the… (more)

Xin, Yuxuan

2014-01-01T23:59:59.000Z

413

Production of high-octane gasoline on a semi-industrial catalytic reforming plant  

Science Journals Connector (OSTI)

Experiments have been carried out on the catalytic reforming at a pressure of 20 atm of a wide, straight-run gasoline fraction on an experimental industrial plant.

A. P. Fedorov; G. N. Maslyanskii…

1967-01-01T23:59:59.000Z

414

E-Print Network 3.0 - advanced catalytic materials--1996 Sample...  

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

Ecology 44 Surface Science Perspectives The unhappy marriage of transition and noble metal atoms: A new Summary: to enhance catalytic activity? (A perspective on: When adding...

415

Measurement of diesel solid nanoparticle emissions using a catalytic stripper for comparison with Europe's PMP protocol  

Broader source: Energy.gov [DOE]

Evaluation and comparison of the measurements of diesel solid nanoparticle emissions using the European Particle Measurement Programme (PMP) system and catalytic stripper

416

New Tandem Catalytic Cycles take to the Rhod(ium) | The Ames...  

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

New Tandem Catalytic Cycles take to the Rhod(ium) Light, combined with a novel rhodium catalyst, enables greener production of chemical feedstocks from biorenewables. A key...

417

Fatigue and environmentally assisted cracking in light water reactors  

SciTech Connect (OSTI)

Fatigue and stress corrosion cracking (SCC) for low-alloy steel used in piping and in steam generator and reactor pressure vessels have been investigated. Fatigue data were obtained on medium-sulfur-content A533-Gr B and A106-Gr B steels in high-purity (HP) deoxygenated water, in simulated pressurized water reactor water, and in air. Analytical studies focused on the behavior of carbon steels in boiling water reactor (BWR) environments. Crack-growth rates of composite fracture-mechanics specimens of A533-Gr B/Inconel-182/Inconel-600 (plated with nickel) and homogeneous specimens of A533-Gr B steel were determined under small-amplitude cyclic loading in HP water with {approx}300 pbb dissolved oxygen. Radiation-induced segregation and irradiation-assisted SCC of Type 304 SS after accumulation of relatively high fluence also have been investigated. Microchemical and microstructural changes in HP and commercial-purity Type 304 SS specimens from control-blade absorber tubes used in two operating BWRs were studied by Auger electron spectroscopy and scanning electron microscopy, and slow-strain-rate tensile tests were conducted on tubular specimens in air and in simulated BWR water at 289{degrees}C.

Kassner, T.F.; Ruther, W.E.; Chung, H.M.; Hicks, P.D.; Hins, A.G.; Park, J.Y.; Shack, W.J.

1992-03-01T23:59:59.000Z

418

De-alloying and stress-corrosion cracking. Final report  

SciTech Connect (OSTI)

This research program has had two major areas of focus that are related: (1) alloy corrosion and (2) the role of selective dissolution in the stress corrosion cracking of alloy systems. These interrelated issues were examined using model systems such as Ag-Au and Cu-Au by conventional electrochemical techniques, in situ scanning tunneling microscopy (STM), in situ small angle neutron scattering (SANS), ultrahigh speed digital photography of fracture events, and computer simulations. The STM and SANS work were specifically aimed at addressing a roughening transition known to occur in alloy systems undergoing corrosion at electrochemical potentials greater than the so-called critical potential. Analytical models of de-alloying processes including the roughening transition were developed that specifically include curvature effects that are important in alloy corrosion processes. Stress-corrosion experiments were performed on the same model systems using rapid optical and electrochemical techniques on 50 {micro}m--250 {micro}m thick sheets and small diameter wires. The primary goal of this work was to develop a fundamental understanding of the corrosion and electrochemistry of alloys and the stress-corrosion cracking processes these alloys undergo. Computer simulations and analytical work identified surface stress and an important parameter in environmentally assisted fracture. The major results of the research on this program since the summer of 1993 are briefly summarized.

Sieradzki, K.

1998-09-01T23:59:59.000Z

419

Catalytic process for converting 2-oxazolidinones to their corresponding alkanolamines  

SciTech Connect (OSTI)

This invention provides a process for recovering alkanolamines, e.g. diisopropanolamine, from their corresponding cyclic reaction products (e.g., oxazolidinones), which products are the result of the reaction of CO/sub 2/ and the alkanolamine, a situation commonly encountered in acid gas removal processes employing the alkanolamines alone or in combination with other liquids such as sulfolane (tetrahydrothiophene-1,1 -dioxide). The process involves hydrolyzing the oxazolidinones in the presence of a small but catalytically effective amount of an amine, preferably from about 2 to 10 weight percent, based on 2-oxazolidinones. Preferably, the amine is the alkanolamine precursor of the corresponding 2-oxazolidinone.

Miller, A. E.

1985-04-30T23:59:59.000Z

420

Plasma-assisted catalytic ionization using porous nickel plate  

SciTech Connect (OSTI)

Hydrogen atomic pair ions, i.e., H{sup +} and H{sup -} ions, are produced by plasma-assisted catalytic ionization using a porous nickel plate. Positive ions in a hydrogen plasma generated by dc arc discharge are irradiated to the porous plate, and pair ions are produced from the back of the irradiation plane. It becomes clear that the production quantity of pair ions mainly depends on the irradiation current of positive ions and the irradiation energy affects the production efficiency of H{sup -} ions.

Oohara, W.; Maeda, T.; Higuchi, T. [Department of Electronic Device Engineering, Yamaguchi University, Ube 755-8611 (Japan)

2011-09-15T23:59:59.000Z

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


421

Development of a Sustainable Catalytic Ester Amidation Process  

Science Journals Connector (OSTI)

Development of a Sustainable Catalytic Ester Amidation Process ... In this paper, and as part of our ongoing interests in the advancement and uptake of green synthesis in a discovery chemistry setting,(17-19) we report our efforts to develop a significantly more sustainable process and demonstrate its applicability to the synthesis of a range of lead-like substrates. ... Overall, consideration of the isolated yields obtained with this new and sustainable coupling protocol indicates that the current method is an extremely viable alternative compared to the previously developed approach. ...

Nicola Caldwell; Craig Jamieson; Iain Simpson; Allan J. B. Watson

2013-07-30T23:59:59.000Z

422

Recent Advances in Catalytic Conversion of Ethanol to Chemicals  

SciTech Connect (OSTI)

With increased availability and decreased cost, ethanol is potentially a promising platform molecule for the production of a variety of value-added chemicals. In this review, we provide a detailed summary of recent advances in catalytic conversion of ethanol to a wide range of chemicals and fuels. We particularly focus on catalyst advances and fundamental understanding of reaction mechanisms involved in ethanol steam reforming (ESR) to produce hydrogen, ethanol conversion to hydrocarbons ranging from light olefins to longer chain alkenes/alkanes and aromatics, and ethanol conversion to other oxygenates including 1-butanol, acetaldehyde, acetone, diethyl ether, and ethyl acetate.

Sun, Junming; Wang, Yong

2014-04-30T23:59:59.000Z

423

Validation of the state-space model of fatigue crack growth in ductile alloys under variable-amplitude load via comparison of the crack-opening stress data  

Science Journals Connector (OSTI)

A state-space model of fatigue crack growth in ductile alloys under variable-amplitude load was presented by Patankar and Ray (Patankar...International Journal of Fracture, 90, 235--249; Patankar and Ray (2000).

Ravindra Patankar; Rong Qu

2005-02-01T23:59:59.000Z

424

DEVELOPMENT AND CONSTRUCTION OF LOW-CRACKING HIGH-PERFORMANCE CONCRETE (LC-HPC) BRIDGE DECKS: FREE SHRINKAGE TESTS, RESTRAINED RING TESTS, CONSTRUCTION EXPERIENCE, AND CRACK SURVEY RESULTS  

E-Print Network [OSTI]

The development, construction, and evaluation of low-cracking high-performance concrete (LC-HPC) bridge decks are described based on laboratory test results and experiences gained during the construction of 13 LC-HPC bridge ...

Yuan, Jiqiu

2011-12-31T23:59:59.000Z

425

Interaction between corrosion crack width and steel loss in RC beams corroded under load  

SciTech Connect (OSTI)

This paper presents results and discussions on an experimental study conducted to relate the rate of widening of corrosion cracks with the pattern of corrosion cracks as well as the level of steel corrosion for RC beams (153 x 254 x 3000 mm) that were corroded whilst subjected to varying levels of sustained loads. Steel corrosion was limited to the tensile reinforcement and to a length of 700 mm at the centre of the beams. The rate of widening of corrosion cracks as well as strains on uncracked faces of RC beams was constantly monitored during the corrosion process, along the corrosion region and along other potential cracking faces of beams using a demec gauge. The distribution of the gravimetric mass loss of steel along the corrosion region was measured at the end of the corrosion process. The results obtained showed that: the rate of widening of each corrosion crack is dependent on the overall pattern of the cracks whilst the rate of corrosion is independent of the pattern of corrosion cracks. A mass loss of steel of 1% was found to induce a corrosion crack width of about 0.04 mm.

Malumbela, Goitseone, E-mail: malumbela@mopipi.ub.b [Dpt. of Civil Eng., Univ. of Cape Town, Private Bag X3, Rondebosch, 7700 (South Africa); Alexander, Mark; Moyo, Pilate [Dpt. of Civil Eng., Univ. of Cape Town, Private Bag X3, Rondebosch, 7700 (South Africa)

2010-09-15T23:59:59.000Z

426

Prediction of reinforcement corrosion using corrosion induced cracks width in corroded reinforced concrete beams  

SciTech Connect (OSTI)

This paper studies the evolution of reinforcement corrosion in comparison to corrosion crack width in a highly corroded reinforced concrete beam. Cracking and corrosion maps of the beam were drawn and steel reinforcement was recovered from the beam to observe the corrosion pattern and to measure the loss of mass of steel reinforcement. Maximum steel cross-section loss of the main reinforcement and average steel cross-section loss between stirrups were plotted against the crack width. The experimental results were compared with existing models proposed by Rodriguez et al., Vidal et al. and Zhang et al. Time prediction models for a given opening threshold are also compared to experimental results. Steel cross-section loss for stirrups was also measured and was plotted against the crack width. It was observed that steel cross-section loss in the stirrups had no relationship with the crack width of longitudinal corrosion cracks. -- Highlights: •Relationship between crack and corrosion of reinforcement was investigated. •Corrosion results of natural process and then corresponds to in-situ conditions. •Comparison with time predicting model is provided. •Prediction of load-bearing capacity from crack pattern was studied.

Khan, Inamullah; François, Raoul [Université de Toulouse, UPS, INSA, LMDC (Laboratoire Matériaux et Durabilité des Constructions), 135, Avenue de Rangueil, F-31077 Toulouse (France)] [Université de Toulouse, UPS, INSA, LMDC (Laboratoire Matériaux et Durabilité des Constructions), 135, Avenue de Rangueil, F-31077 Toulouse (France); Castel, Arnaud [Centre for Infrastructure Engineering and Safety, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW (Australia)] [Centre for Infrastructure Engineering and Safety, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW (Australia)

2014-02-15T23:59:59.000Z

427

THE ELASTIC-PLASTIC MECHANICS OF CRACK EXTENSION James R. Rice*  

E-Print Network [OSTI]

THE ELASTIC-PLASTIC MECHANICS OF CRACK EXTENSION James R. Rice* ABSTRACT This paper briefly reviews progres~in the elastic plastic analysisof crack extension. Analytical results for plane strain and plane stress deformation fields are noted, and elastic-plastic fracture instability as well as transitional

428

Adsorption and Desorption of Hydrocarbons on a Supported Nickel Cracking Catalyst  

Science Journals Connector (OSTI)

...Hydrocarbons on a Supported Nickel Cracking Catalyst A. K. Galwey A study has been made...a high area supported nickel cracking catalyst. Measurements have been made of (i...adsorbed, after standard preparation of the catalyst, when a known volume of each hydrocarbon...

1963-01-01T23:59:59.000Z

429

Sorption and Diffusion of Simple Paraffins in Silica-Alumina Cracking Catalyst  

Science Journals Connector (OSTI)

...Paraffins in Silica-Alumina Cracking Catalyst R. M. Barrer T. Gabor Sorption and...propane in the silica-alumina cracking catalyst previously employed in similar measurements...behaviour in the micropore structure of the catalyst, for the species studied. The ratio...

1960-01-01T23:59:59.000Z

430

TRANSIENT FATIGUE-CRACK GROWTH BEHAVIOR FOLLOWING VARIABLE-AMPLITUDE LOADING IN A  

E-Print Network [OSTI]

TRANSIENT FATIGUE-CRACK GROWTH BEHAVIOR FOLLOWING VARIABLE-AMPLITUDE LOADING IN A MONOLITHIC-crack growth behavior following variable-amplitude loading sequences has been investigated in a hot-toughened ceramics [13] following various variable-amplitude loading sequences. Transient retardations, involving

Ritchie, Robert

431

Statistical fracture modeling: crack path and fracture criteria with application to homogeneous and  

E-Print Network [OSTI]

Statistical fracture modeling: crack path and fracture criteria with application to homogeneous; accepted 23 January 2002 Abstract Analysis has been performed on fracture initiation near a crack in a brittle material with strength described by Weibull statistics. This nonlocal fracture model allows

Ritchie, Robert

432

Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D  

E-Print Network [OSTI]

Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D W. Zhou*, T. Z. Long and C. K ductility, and the HAZ was found to be the `weakest link'. Keywords: Magnesium alloy, AZ91D, TIG welding, Hot cracking, Liquation, Fracture Introduction Magnesium alloys have high strength/weight ratio

Zhou, Wei

433

The effects of stress and fluid pressure on the anisotropy of interconnected cracks  

Science Journals Connector (OSTI)

......compressive stress, as it hinders the process of crack closure (Fig. 1a). Crack...decreasing the anisotropy. These two competing processes explain the rise in the anisotropy parameters...effective pressure, in 70th Ann. Int. Mtg SEG, Exp. Abs., pp. 1826-1829....

S. R. Tod

2002-04-01T23:59:59.000Z

434

Brittle fracture in a periodic structure with internal potential energy. Spontaneous crack propagation  

E-Print Network [OSTI]

Spontaneous brittle fracture is studied based on the recently introduced model (Mishuris and Slepyan, Brittle fracture in a periodic structure with internal potential energy. Proc. Roy. Soc. A, in press). A periodic structure is considered, where only the prospective crack-path layer is specified as a discrete set of alternating initially stretched and compressed bonds. A bridged crack destroying initially stretched bonds may propagate under a certain level of the internal energy without external sources. The general analytical solution with the crack speed $-$ energy relation is presented in terms of the crack-related dynamic Green's function. For the anisotropic two-line chain and lattice considered earlier in quasi-statics, the dynamic problem is examined in detail. The crack speed is found to grow unboundedly as the energy approaches its upper limit. It is revealed that the spontaneous fracture can occur in the form of a pure bridged, partially bridged or fully open crack depending on the internal energy level. Generally, the steady-state mode of the crack propagation is found to be realised, whereas an irregular growth, clustering and the crack speed oscillations are detected in a vicinity of the lower bound of the energy.

Mark Ayzenberg-Stepanenko; Gennady Mishuris; Leonid Slepyan

2014-02-12T23:59:59.000Z

435

DEVELOPMENT OF NONLINEAR TIME REVERSED ACOUSTICS (NLTRA) FOR APPLICATIONS TO CRACK DETECTION IN SOLIDS  

E-Print Network [OSTI]

of Nondestructive Evaluation (NDE) exhibit extremely high sensitivity to the presence of cracks. Time Reverse stones and long-distance communication in the ocean. The Nondestructive Evaluation (NDE) applications,4] and detection of cracks in a thin air-filled hollow cylinder [5]. A review of TRA applications to NDE is given

436

Autonomous Crack Displacement Monitoring of a Residence Near a Quarry David E. Kosnik, Northwestern University  

E-Print Network [OSTI]

Autonomous Crack Displacement Monitoring of a Residence Near a Quarry David E. Kosnik, Northwestern remote mon- itoring of cracks in interior and exterior walls of a residence near a limestone quarry for construction and raw materials. For instance, neighbors of road aggregate quarries often perceive

437

Autonomous Remote Crack Displacement Monitoring of a Residence Near a Limestone  

E-Print Network [OSTI]

Autonomous Remote Crack Displacement Monitoring of a Residence Near a Limestone Quarry, Naples a limestone quarry. The object is to quantitatively compare crack re- sponse to blast-induced ground motion for construction and raw materials. For instance, neighbors of road aggregate quarries often perceive

438

Fatigue failure in thin-film polycrystalline silicon is due to subcritical cracking within the oxide layer  

E-Print Network [OSTI]

Fatigue failure in thin-film polycrystalline silicon is due to subcritical cracking within with stress-induced surface oxide thicken- ing and moisture-assisted subcritical cracking in the amor- phous

Ritchie, Robert

439

Analysis of Fatigue Crack Growth under Random Load Sequences Derived from Military In-flight Load Data  

Science Journals Connector (OSTI)

The crack growth process of a crack initiating at a hole of a skin-stringer panel in a fighter aircraft subjected to random variable amplitude loading is investigated in this paper. The generation of synthetic...

C. Mattrand; J. -M. Bourinet; D. Théret

2011-01-01T23:59:59.000Z

440

Bilateral propagation of a spontaneous two-dimensional anti-plane shear crack under the influence of cohesion  

Science Journals Connector (OSTI)

......cracks, the calculations of the time- dependent fault motions and the corresponding seismograms as the crack propagates, pro- ceed much as in the cases of uniform extension. The principal differences are that, whereas the coordinates of the edges can be......

A. K. Chatterjee; L. Knopoff

1983-05-01T23:59:59.000Z

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


441

HEATS: Thermal Energy Storage  

SciTech Connect (OSTI)

HEATS Project: The 15 projects that make up ARPA-E’s HEATS program, short for “High Energy Advanced Thermal Storage,” seek to develop revolutionary, cost-effective ways to store thermal energy. HEATS focuses on 3 specific areas: 1) developing high-temperature solar thermal energy storage capable of cost-effectively delivering electricity around the clock and thermal energy storage for nuclear power plants capable of cost-effectively meeting peak demand, 2) creating synthetic fuel efficiently from sunlight by converting sunlight into heat, and 3) using thermal energy storage to improve the driving range of electric vehicles (EVs) and also enable thermal management of internal combustion engine vehicles.

None

2012-01-01T23:59:59.000Z

442

Holographic thermalization patterns  

E-Print Network [OSTI]

We investigate the behaviour of various correlators in N=4 super Yang Mills theory, taking finite coupling corrections into account. In the thermal limit we investigate the flow of the quasinormal modes as a function of the 't Hooft coupling. Then by using a specific model of holographic thermalization we investigate the deviation of the spectral densities from their thermal limit in an out-of-equilibrium situation. The main focus lies on the thermalization pattern with which the various plasma constituents of different energies approach their final thermal distribution as the coupling constant decreases from the infinite coupling limit. All results point towards the weakening of the usual top down thermalization pattern.

Stefan Stricker

2014-03-11T23:59:59.000Z

443

Holographic thermalization patterns  

E-Print Network [OSTI]

We investigate the behaviour of various correlators in N=4 super Yang Mills theory, taking finite coupling corrections into account. In the thermal limit we investigate the flow of the quasinormal modes as a function of the 't Hooft coupling. Then by using a specific model of holographic thermalization we investigate the deviation of the spectral densities from their thermal limit in an out-of-equilibrium situation. The main focus lies on the thermalization pattern with which the various plasma constituents of different energies approach their final thermal distribution as the coupling constant decreases from the infinite coupling limit. All results point towards the weakening of the usual top down thermalization pattern.

Stricker, Stefan

2014-01-01T23:59:59.000Z

444

Hydride-phase formation and its influence on fatigue crack propagationbehavior in a Zircaloy-4 alloy  

SciTech Connect (OSTI)

The hydride-phase formation and its influence on the fatigue behavior of a Zircaloy-4 alloy charged with hydrogen gas are investigated. First, the microstructure and fatigue crack propagation rate of the alloy in the as-received condition are studied. Second, the formation and homogeneous distribution of delta zirconium hydride ( -ZrH2) in the bulk, and its effect on the fatigue crack propagation rate are presented. The results show that in the presence of hydrides the zirconium alloy exhibits reduced toughness and enhanced crack growth rates. Finally, the influence of a pre-existing fatigue crack in the specimen and the subsequent hydride formation were investigated. The residual lattice strain profile around the fatigue crack tip was measured using neutron diffraction. The combined effects of residual strains and hydride precipitation on the fatigue behavior are discussed.

Garlea, Elena [University of Tennessee, Knoxville (UTK); Choo, H. [University of Tennessee, Knoxville (UTK); Wang, G Y [University of Tennessee, Knoxville (UTK); Liaw, Peter K [University of Tennessee, Knoxville (UTK); Clausen, B [Los Alamos National Laboratory (LANL); Brown, D. W. [Los Alamos National Laboratory (LANL); Park, Jae-Sung [University of Tennessee, Knoxville (UTK); Rack, P. D. [University of Tennessee, Knoxville (UTK); Kenik, Edward A [ORNL

2010-01-01T23:59:59.000Z

445

Fatigue crack propagation in a quasi one-dimensional elasto-plastic model  

E-Print Network [OSTI]

Fatigue crack advance induced by the application of cyclic quasistatic loads is investigated both numerically and analytically using a lattice spring model. The system has a quasi-one-dimensional geometry, and consists in two symmetrical chains that are pulled apart, thus breaking springs which connect them, and producing the advance of a crack. Quasistatic crack advance occurs as a consequence of the plasticity included in the springs which form the chains, and that implies a history dependent stress-strain curve for each spring. The continuous limit of the model allows a detailed analytical treatment that gives physical insight of the propagation mechanism. This simple model captures key features that cause well known phenomenology in fatigue crack propagation, in particular a Paris-like law of crack advance under cyclic loading, and the overload retardation effect.

Tomás M. Guozden; Eduardo A. Jagla

2012-06-27T23:59:59.000Z

446

Characterization of elevated temperature crack growth in Hastelloy-X using integral parameters  

SciTech Connect (OSTI)

Linear elastic fracture mechanics approaches are not suitable for prediction of fatigue crack growth in the nonlinear regime at elevated temperatures. The objective of this paper is to investigate the ability of the integral parameters by Blackburn (J*), by Kishimoto et al. ({cflx J}), and by Atluri et al. ({Delta}Tp*, {Delta}Tp) to correlate crack growth data of Hastelloy-X at elevated temperatures under nominally elastic and nominally plastic loading. Crack growth is analyzed using a finite element method, and the integral parameters are computed from the results of analysis. The experimental crack growth rates are correlated with these parameters. It is found that J*, {cflx J}, and {Delta}Tp* can correlate crack growth data within an acceptable accuracy.

Kim, K.S. [Pohang Univ. of Science and Technology (Korea, Republic of). Dept. of Mechanical Engineering; Van Stone, R.H. [General Electric Aircraft Engines, Cincinnati, OH (United States)

1995-07-01T23:59:59.000Z

447

Catalytic ignition of fuel/oxygen/nitrogen mixtures over platinum  

SciTech Connect (OSTI)

Ignition of fuel/oxygen/nitrogen mixtures over platinum wire is experimentally studied by using microcalorimetry and by restricting the flow to the low Reynolds number range so that axisymmetry prevails. The fuels studied are propane, butane, propylene, ethylene, carbon monoxide, and hydrogen. Parameters investigated include flow velocity, fuel type and concentration, and oxygen concentration. The catalytic ignition temperatures of the various fuels are accurately determined over extensive ranges of fuel/oxygen/nitrogen concentrations. Results show two distinctly opposite ignition trends depending on the nature of the fuel. That is, the ignition temperature of lean propane/air and butane/air mixtures decreases as their fuel concentration is increased, while the reverse trend is observed for lean mixtures of propylene, ethylene, carbon monoxide, and hydrogen with air. Furthermore, the ignition of propane depends primarily on fuel concentration, while the ignition of carbon monoxide depends on fuel and oxygen concentrations to a comparable extent. These results are explained on the basis of hierarchical surface adsorption strengths of the different reactants in effecting catalytic ignition. Additional phenomena of interest are observed and discussed.

Cho, P.; Law, C.K.

1986-11-01T23:59:59.000Z

448

Catalytic combustor for integrated gasification combined cycle power plant  

DOE Patents [OSTI]

A gasification power plant 10 includes a compressor 32 producing a compressed air flow 36, an air separation unit 22 producing a nitrogen flow 44, a gasifier 14 producing a primary fuel flow 28 and a secondary fuel source 60 providing a secondary fuel flow 62 The plant also includes a catalytic combustor 12 combining the nitrogen flow and a combustor portion 38 of the compressed air flow to form a diluted air flow 39 and combining at least one of the primary fuel flow and secondary fuel flow and a mixer portion 78 of the diluted air flow to produce a combustible mixture 80. A catalytic element 64 of the combustor 12 separately receives the combustible mixture and a backside cooling portion 84 of the diluted air flow and allows the mixture and the heated flow to produce a hot combustion gas 46 provided to a turbine 48. When fueled with the secondary fuel flow, nitrogen is not combined with the combustor portion.

Bachovchin, Dennis M. (Mauldin, SC); Lippert, Thomas E. (Murrysville, PA)

2008-12-16T23:59:59.000Z

449

Decomposition of molybdate-hexamethylenetetramine complex: One single source route for different catalytic materials  

SciTech Connect (OSTI)

Decomposition of ammonium heptamolybdate-hexamethylentetramine (HMTA) complex (HMTA){sub 2}(NH{sub 4}){sub 4}Mo{sub 7}O{sub 24}.2H{sub 2}O was studied as a function of treatment conditions in the range 300-1173 K. The evolution of solid products during decomposition was studied by thermal analysis and in situ EXAFS. Depending on the nature of the gas used for treatment, single phases of highly dispersed nitrides Mo{sub 2}N, carbide Mo{sub 2}C, or oxide MoO{sub 2} can be obtained. The nature of the products obtained was explained by qualitative thermodynamical considerations. Morphology of the solids considerably depends on such preparation parameters as temperature and mass velocity of the gas flow. For the nitride-based materials, catalytic activity was evaluated in the model thiophene HDS reaction. It was demonstrated that NH{sub 3}-treated samples showed better catalytic activity than N{sub 2}-treated ones due to cleaner surface and better morphology. Transmission microscopy, XRD and XPS studies showed that MoS{sub 2} is formed on the surface during HDS reaction or sulfidation with H{sub 2}S. Optimized nitride-derived catalysts showed mass activity several times higher than unsupported MoS{sub 2} or MoS{sub 2}/Al{sub 2}O{sub 3} reference catalyst. - Graphical Abstract: Depending on the conditions, decomposition of molybdate-HTMA complex yields highly dispersed molybdenum nitride, carbide or oxide. Research Highlights: > Decomposition of molybdate-HTMA complex yields highly dispersed Mo{sub 2}N, Mo{sub 2}C or MoO{sub 2}. > In situ EXAFS shows formation of common amorphous product MoC{sub x}N{sub y}O{sub z} at 673 K. > Crystalline Mo{sub 2}N with surface area near 200 m{sup 2}/g was obtained at 823 K. > High mass activity in thiophene HDS was observed.

Chouzier, Sandra [Institut de recherches sur la catalyse et l'environnement de Lyon UMR5256, CNRS-Universite de Lyon 1, 2 avenue Albert Einstein, 69626 Villeurbanne cedex (France); Czeri, Tivadar; Roy-Auberger, Magalie; Pichon, Christophe [IFP Energies nouvelles, BP 3, 69390 Vernaison (France); Geantet, Christophe; Vrinat, Michel [Institut de recherches sur la catalyse et l'environnement de Lyon UMR5256, CNRS-Universite de Lyon 1, 2 avenue Albert Einstein, 69626 Villeurbanne cedex (France); Afanasiev, Pavel, E-mail: pavel.afanasiev@ircelyon.univ-lyon1.fr [Institut de recherches sur la catalyse et l'environnement de Lyon UMR5256, CNRS-Universite de Lyon 1, 2 avenue Albert Einstein, 69626 Villeurbanne cedex (France)

2011-10-15T23:59:59.000Z

450

Review of industry efforts to manage pressurized water reactor feedwater nozzle, piping, and feedring cracking and wall thinning  

SciTech Connect (OSTI)

This report presents a review of nuclear industry efforts to manage thermal fatigue, flow-accelerated corrosion, and water hammer damage to pressurized water reactor (PWR) feedwater nozzles, piping, and feedrings. The review includes an evaluation of design modifications, operating procedure changes, augmented inspection and monitoring programs, and mitigation, repair and replacement activities. Four actions were taken: (a) review of field experience to identify trends of operating events, (b) review of technical literature, (c) visits to PWR plants and a PWR vendor, and (d) solicitation of information from 8 other countries. Assessment of field experience is that licensees have apparently taken sufficient action to minimize feedwater nozzle cracking caused by thermal fatigue and wall thinning of J-tubes and feedwater piping. Specific industry actions to minimize the wall-thinning in feedrings and thermal sleeves were not found, but visual inspection and necessary repairs are being performed. Assessment of field experience indicates that licensees have taken sufficient action to minimize steam generator water hammer in both top-feed and preheat steam generators. Industry efforts to minimize multiple check valve failures that have allowed backflow of steam from a steam generator and have played a major role in several steam generator water hammer events were not evaluated. A major finding of this review is that analysis, inspection, monitoring, mitigation, and replacement techniques have been developed for managing thermal fatigue and flow-accelerated corrosion damage to feedwater nozzles, piping, and feedrings. Adequate training and appropriate applications of these techniques would ensure effective management of this damage.

Shah, V.N.; Ware, A.G.; Porter, A.M.

1997-03-01T23:59:59.000Z

451

Non-thermal Plasma Chemistry Non-thermal Thermal  

E-Print Network [OSTI]

automotive industry optics biomedical technology environmental technology Plasma Technology Quote from: Pla-thermal Plasma Chemical Flow Reactor #12;Werner von Siemens ,, ... construction of an apparatus generation (1857) pollution control volatile organic components, NOx reforming, ... radiation sources excimer

Greifswald, Ernst-Moritz-Arndt-Universität

452

Characterization and catalytic performance of vanadium supported on sulfated Ti-PILC catalysts issued from different Ti-precursors in selective catalytic reduction of nitrogen oxide by ammonia  

Science Journals Connector (OSTI)

Vanadium supported on sulfated Ti-pillared clay catalysts (STi-PILCs) issued from different Ti-precursors were investigated for selective catalytic reduction (SCR) of NO by NH3 in the presence of O2. The STi-PILC...

J. Arfaoui; L. Khalfallah Boudali; A. Ghorbel; G. Delahay

2009-12-01T23:59:59.000Z

453

Monitoring Thermal Fatigue Damage In Nuclear Power Plant Materials Using Acoustic Emission  

SciTech Connect (OSTI)

Proactive aging management of nuclear power plant passive components requires technologies to enable monitoring and accurate quantification of material condition at early stages of degradation (i.e., pre-macrocrack). Acoustic emission (AE) is well-suited to continuous monitoring of component degradation and is proposed as a method to monitor degradation during accelerated thermal fatigue tests. A key consideration is the ability to separate degradation responses from external sources such as water spray induced during thermal fatigue testing. Water spray provides a significant background of acoustic signals, which can overwhelm AE signals caused by degradation. Analysis of AE signal frequency and energy is proposed in this work as a means for separating degradation signals from background sources. Encouraging results were obtained by applying both frequency and energy filters to preliminary data. The analysis of signals filtered using frequency and energy provides signatures exhibiting several characteristics that are consistent with degradation accumulation in materials. Future work is planned to enable verification of the efficacy of AE for thermal fatigue crack initiation detection. While the emphasis has been placed on the use of AE for crack initiation detection during accelerated aging tests, this work also has implications with respect to the use of AE as a primary tool for early degradation monitoring in nuclear power plant materials. The development of NDE tools for characterization of aging in materials can also benefit from the use of a technology such as AE which can continuously monitor and detect crack initiation during accelerated aging tests.

Meyer, Ryan M.; Ramuhalli, Pradeep; Watson, Bruce E.; Pitman, Stan G.; Roosendaal, Timothy J.; Bond, Leonard J.

2012-04-26T23:59:59.000Z

454

A continuing investigation into the stress field around two parallet-edge cracks in a finite body  

E-Print Network [OSTI]

,7 ........................................................................................... 5 2.1 Two Parallel Edge Cracks in a Four Point Bending Member.............................. 7 2.2 Westergaard Stress Functions and Resulting Stress Intensity Factors for a Crack with Applied Tractions Along Its Faces... .................................................................... 31 4.2 Mesh Created for Numerical Model (Zoomed in on Crack Interaction Region) ............................................................................................. 32 5.1 Open Mode Stress Intensity Factor Percent...

Gilman, Justin Patrick

2005-02-17T23:59:59.000Z

455

Thin Film Cracking Modulated by Underlayer Creep by J. Liang, R. Huang, J.H. Prvost, and Z. Suo  

E-Print Network [OSTI]

: subcritical decohesion at the crack tip, and creep in the underlayer. In a thin-film microbridge over for the growth rate per temperature cycle of a channel crack in a brittle film, induced by ratcheting plasticThin Film Cracking Modulated by Underlayer Creep by J. Liang, R. Huang, J.H. Prévost, and Z. Suo

Huang, Rui

456

Effect of Surface Morphology on Crack Growth at a Sol-Gel Reinforced Epoxy/Aluminum Interface  

E-Print Network [OSTI]

the measurements of the critical energy-release rate, subcritical crack-growth kinetics, and threshold energyEffect of Surface Morphology on Crack Growth at a Sol-Gel Reinforced Epoxy/Aluminum Interface Jiong. Keywords: ADCB wedge test; Crack growth; Durability; Epoxy=aluminum; Sol-gel coating; Surface pretreatment

Chaudhury, Manoj K.

457

Thermal contact resistance  

E-Print Network [OSTI]

This work deals with phenomena of thermal resistance for metallic surfaces in contact. The main concern of the work is to develop reliable and practical methods for prediction of the thermal contact resistance for various ...

Mikic, B. B.

1966-01-01T23:59:59.000Z

458

Solar Thermal Processes  

Science Journals Connector (OSTI)

The use of solar energy for desalination purposes was one of ... The process is based on the use of solar thermal energy to evaporate water, thus separating pure ... brine. In this chapter an overview of solar thermal

M.T. Chaibi; Ali M. El-Nashar

2009-01-01T23:59:59.000Z

459

Thermal Neutron Scattering  

Science Journals Connector (OSTI)

... of its title. It is not for the nuclear physicist, nor even for the neutron physicist, but for the student of solids and liquids. "Thermal ... physicist, but for the student of solids and liquids. "Thermal neutron ...

G. E. BACON

1968-11-09T23:59:59.000Z

460

Production of Hydrogen from Bio-oil Using Low-temperature Electrochemical Catalytic Reforming Approach over CoZnAl Catalyst  

Science Journals Connector (OSTI)

High-efficient production of hydrogen from bio-oil was performed by electrochemical catalytic reforming method over the CoZnAl catalyst. The influence of current on the hydrogen yield, carbon conversion, and products distribution were investigated. Both the hydrogen yield and carbon conversion were remarkably enhanced by the current through the catalyst, reaching hydrogen yield of 70% and carbon conversion of 85% at a lower reforming temperature of 500°C. The influence of current on the properties of the CoZnAl catalyst was also characterized by X-ray diffraction, X-ray photoelectron spectroscopy, thermal gravimetric analysis, and Brunauer-Emmett-Teller measurements. The thermal electrons would play an important role in promoting the reforming reactions of the oxygenated-organic compounds in the bio-oil.

Shao-bin Lin; Tong-qi Ye; Li-xia Yuan; Tao Hou; Quan-xin Li

2010-01-01T23:59:59.000Z

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


461

Production of renewable jet fuel range alkanes and commodity chemicals from integrated catalytic  

E-Print Network [OSTI]

, carbohydrate hydrolysis and dehydration, and catalytic upgrading of platform chemicals. The technology centersProduction of renewable jet fuel range alkanes and commodity chemicals from integrated catalytic and subsequently upgrading these two platforms into a mixture of branched, linear, and cyclic alkanes of molecular

California at Riverside, University of

462

Evolution of Domain Architectures and Catalytic Functions of Enzymes in Metabolic Systems  

E-Print Network [OSTI]

Evolution of Domain Architectures and Catalytic Functions of Enzymes in Metabolic Systems Summit architectures and catalytic functions of enzymes constitute the centerpieces of a metabolic network. These types. In contrast, prokaryotic enzymes become more versatile by catalyzing multiple reactions with similar chemical

Yeang, Chen-Hsiang

463

Control of Natural Gas Catalytic Partial Oxidation for Hydrogen Generation in Fuel Cell Applications1  

E-Print Network [OSTI]

Control of Natural Gas Catalytic Partial Oxidation for Hydrogen Generation in Fuel Cell Ghosh3 , Huei Peng2 Abstract A fuel processor that reforms natural gas to hydrogen-rich mixture to feed of the hydrogen in the fuel processor is based on catalytic partial oxidation of the methane in the natural gas

Peng, Huei

464

Effect of the Catalyst Load on Syngas Production in Short Contact Time Catalytic Partial Oxidation Reactors  

Science Journals Connector (OSTI)

Effect of the Catalyst Load on Syngas Production in Short Contact Time Catalytic Partial Oxidation Reactors ... For safety and environmental protection reasons (to avoid syngas release into the atmosphere), after the analysis section, the reacted gas stream was completely oxidized by forced air in a catalytic honeycomb burner (Figure 2). ...

S. Specchia; L. D. Vella; B. Lorenzut; T. Montini; V. Specchia; P. Fornasiero

2009-07-22T23:59:59.000Z

465

Catalytic study of SOFC electrode materials in engine exhaust gas Pauline Briaulta  

E-Print Network [OSTI]

cathode materials, besides LSCF demonstrated a lower catalytic activity towards hydrocarbon partial corresponding to a composition of exhaust gas. A screening of four cathode materials was done, some well selected as the electrolyte material. Chemical stability tests and catalytic activity studies in the gas

Paris-Sud XI, Université de

466

Catalytic Conversion of Ethanol to Hydrogen Using Combinatorial Shici Duan and Selim Senkan*  

E-Print Network [OSTI]

the single component catalytic materials explored. Introduction Due to their high energy conversionCatalytic Conversion of Ethanol to Hydrogen Using Combinatorial Methods Shici Duan and Selim Senkan using a feed gas composition of 2% C2H5OH and 12% H2O in a helium carrier gas. This systematic

Senkan, Selim M.

467

Engineering a Unimolecular DNA-Catalytic Probe for Single Lead Ion Monitoring  

E-Print Network [OSTI]

Engineering a Unimolecular DNA-Catalytic Probe for Single Lead Ion Monitoring Hui Wang, Youngmi Kim reactions. These catalytic DNAs, or DNAzymes, can be activated by metal ions. In this paper, we take advantage of DNA molecular engineering to improve the properties of DNAzymes by designing a unimolecular

Tan, Weihong

468

Scaling behavior of optimally structured catalytic microfluidic reactors Fridolin Okkels and Henrik Bruus  

E-Print Network [OSTI]

Scaling behavior of optimally structured catalytic microfluidic reactors Fridolin Okkels and Henrik of catalytic microfluidic reactors we show that, when optimally structured, these reactors share underlying the reactor using a high-level implementation of topology optimization. DOI: 10.1103/PhysRevE.75.016301 PACS

469

The Catalytic Chemistry of HCN+NO over Na- and Ba-Y, FAU: An...  

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

The Catalytic Chemistry of HCN+NO over Na- and Ba-Y, FAU: An In Situ FTIR and TPDTPR Study. The Catalytic Chemistry of HCN+NO over Na- and Ba-Y, FAU: An In Situ FTIR and TPDTPR...

470

EMAT based inspection of natural gas pipelines for SSC cracks  

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

EMAT-Based Inspection of Natural Gas EMAT-Based Inspection of Natural Gas Pipelines for Stress Corrosion Cracks FY2004 Report Venugopal K. Varma, Raymond W. Tucker, Jr., and Austin P. Albright Oak Ridge National Laboratory Oak Ridge, Tennessee 37831 1 This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name,

471

Thermal-mechanical fatigue behavior of nickel-base superalloys. Final Report  

SciTech Connect (OSTI)

The main achievements of a 36-month research program are presented. The main objective was to gain more insight into the problem of crack growth under thermal mechanical fatigue (TMF) conditions. This program was conducted at M.I.T. for the period of September 1982 to September 1985. The program was arranged into five technical tasks. Under Task I, the literature of TMF data was reviewed. The goal was to identify the crack propagation conditions in aircraft engines (hot section) and to assess the validity of conventional fracture mechanics parameters to address TMF crack growth. The second task defined the test facilities, test specimen and the testing conditions needed to establish the effectiveness of data correlation parameters identified in Task I. Three materials (Inconel X-750, Hastelloy-X, and B-1900) were chosen for the program. Task II was accomplished in collaboration with Pratt and Whitney Aircraft engineers. Under Task III, a computerized testing system to measure the TMF behavior (LCF and CG behaviors) of various alloys systems was built. The software used to run isothermal and TMF tests was also developed. Built around a conventional servohydraulic machine, the system is capable of push-pull tests under stress or strain and temperature controlled conditions in the temperature range of 25C to 1050C. A crack propagation test program was defined and conducted under Task IV. The test variables included strain range, strain rate (frequency) and temperature. Task V correlated and generalized the Task IV data for isothermal and variable temperature conditions so that several crack propagation parameters could be compared and evaluated. The structural damage (mode of cracking and dislocation substructure) under TMF cycling was identified and contrasted with the isothermal damage to achieve a sound fundamental mechanistic understanding of TMF.

Pelloux, R.M.; Marchand, N.

1986-03-01T23:59:59.000Z

472

Design of a novel conduction heating based stress-thermal cycling apparatus for composite materials and its utilization to characterize composite microcrack damage thresholds  

E-Print Network [OSTI]

???????????..?????????47 viii CHAPTER Page 4.4 Thermal Loading Combined with Bending Conditions?????? 49 4.5 Thermo-Viscoelastic Constitutive....1 Characterization of Crack Formation and Propagation Mechanism?. 93 6.2 Analytical Study of Time Dependent Non-Isothermal Linear Thermo-Viscoelasticity??????????????????...94 6.3 Initial Damage Characterization??????????????.. 101 6.3.1 Cryogenic Temperature...

Ju, Jaehyung

2006-10-30T23:59:59.000Z

473

Thermal neutron detection system  

DOE Patents [OSTI]

According to the present invention, a system for measuring a thermal neutron emission from a neutron source, has a reflector/moderator proximate the neutron source that reflects and moderates neutrons from the neutron source. The reflector/moderator further directs thermal neutrons toward an unmoderated thermal neutron detector.

Peurrung, Anthony J. (Richland, WA); Stromswold, David C. (West Richland, WA)

2000-01-01T23:59:59.000Z

474

Thermal Performance Benchmarking (Presentation)  

SciTech Connect (OSTI)

This project will benchmark the thermal characteristics of automotive power electronics and electric motor thermal management systems. Recent vehicle systems will be benchmarked to establish baseline metrics, evaluate advantages and disadvantages of different thermal management systems, and identify areas of improvement to advance the state-of-the-art.

Moreno, G.

2014-11-01T23:59:59.000Z

475

Multiwavelength Thermal Emission  

E-Print Network [OSTI]

Multiwavelength Astronomy NASA #12;Thermal Emission #12;Thermal Emission Non-thermal p-p collisions Optical IR Radio/ Microwave sources of emission massive stars, WHIM, Ly many dust, cool objects-ray ~GeV Gamma-ray ~TeV sources of emission AGN, clusters, SNR, binaries, stars AGN (obscured), shocks

California at Santa Cruz, University of

476

Microsoft Word - 41891_SWPC_Catalytic Combustor_Factsheet_Rev01_04-24.doc  

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

891_SWPC_CATALYTIC COMBUSTOR_FACTSHEET_REV01_04-24.DOC 891_SWPC_CATALYTIC COMBUSTOR_FACTSHEET_REV01_04-24.DOC Facts Sheet: Catalytic Combustor for Fuel Flexible Gas Turbine (DE-FC26-03NT41891) I. PROJECT PARTICIPANTS A. Siemens Westinghouse Power Corporation B. Caterpillar/Solar Turbine C. Penn State University D. Southern Company Services II. PROJECT DESCRIPTION A. Objective: To develop and demonstrate a cost effective, fuel flexible (syngas/natural gas) catalytic combustor that will achieve ultra low NOx emissions (2ppm) at the exit of the gas turbine and without the use of backend cleanup in Integrated Gasification Combined Cycle (IGCC) application. B. Background/Relevancy 1. Background: Catalytic combustion has been shown to achieve lowest emissions in conventional gas turbine application (natural gas only). Available technical data indicate that it can be effective

477

Thermal imaging measurement of lateral diffusivity and non-invasive material defect detection  

DOE Patents [OSTI]

A system and method for determining lateral thermal diffusivity of a material sample using a heat pulse; a sample oriented within an orthogonal coordinate system; an infrared camera; and a computer that has a digital frame grabber, and data acquisition and processing software. The mathematical model used within the data processing software is capable of determining the lateral thermal diffusivity of a sample of finite boundaries. The system and method may also be used as a nondestructive method for detecting and locating cracks within the material sample.

Sun, Jiangang (Westmont, IL); Deemer, Chris (Downers Grove, IL)

2003-01-01T23:59:59.000Z

478

Analysis of thermal transfer of reinforced concrete submarine oil tanks  

SciTech Connect (OSTI)

The temperature distributions of reinforced concrete submarine oil tanks (RCSOT) obtained by the flat wall method and the cylinder wall method, are compared with the experimental data of the thermal transfer of the RCSOT. The precision and suitable scope of the different methods are discussed. The principle for selecting analysis method for solving thermal transfer of the RCSOT is given. The analytical and experimental temperature distributions show that the wall of the RCSOT should consist of double layer walls and the empty space between double layer walls should be filled with sand or other heat insulation materials to reduce the temperature difference between the inner and outer surfaces of the wall and to prevent the concrete from cracking.

Song, Y.P.; Zhao, G.F. [Dalian Univ. of Technology (China)

1994-12-31T23:59:59.000Z

479

Hydrocarbons Heterogeneous Pyrolysis: Experiments and Modeling for Scramjet Thermal Management  

E-Print Network [OSTI]

The last years saw a renewal of interest for hypersonic research in general and regenerative cooling specifically, with a large increase of the number of dedicated facilities and technical studies. In order to quantify the heat transfer in the cooled structures and the composition of the cracked fuel entering the combustor, an accurate model of the thermal decomposition of the fuel is required. This model should be able to predict the fuel chemical composition and physical properties for a broad range of pressures, temperatures and cooling geometries. For this purpose, an experimental and modeling study of the thermal decomposition of generic molecules (long-chain or polycyclic alkanes) that could be good surrogates of real fuels, has been started at the DCPR laboratory located in Nancy (France). This successful effort leads to several versions of a complete kinetic model. These models do not assume any effect from the material that constitutes the cooling channel. A specific experimental study was performed ...

Bouchez, Marc; Visez, Nicolas; Herbinet, Olivier; Fournet, René; Marquaire, Paul-Marie

2009-01-01T23:59:59.000Z

480

Full-field characterization of thermal diffusivity in continuous- fiber ceramic composite materials and components  

SciTech Connect (OSTI)

Continuous-fiber ceramic matrix composites (CFCCs) are currently being developed for various high-temperature applications, including use in advanced heat engines. Among the material classes of interest for such applications are silicon carbide (SiC)-fiber-reinforced SiC (SiC{sub (f)}/SiC), SiC-fiber-reinforced silicon nitride (SiC {sub (f)}/Si{sub 3}N{sub 4}), aluminum oxide (Al{sub 2}O{sub 3})-fiber-reinforced Al{sub 2}O{sub 3} (Al{sub 2}O{sub 3}{sub (f)}/Al{sub 2}O{sub 3}), and others. In such composites, the condition of the interfaces (between the fibers and matrix) are critical to the mechanical and thermal behavior of the component (as are conventional mechanical defects such as cracks, porosity, etc.). For example, oxidation of this interface (especially on carbon coated fibers) can seriously degrade both mechanical and thermal properties. Furthermore, thermal shock damage can degrade the matrix through extensive crack generation. A nondestructive evaluation method that could be used to assess interface condition, thermal shock damage, and to detect other ``defects`` would thus be very beneficial, especially if applicable to full-scale components. One method under development uses infrared thermal imaging to provide ``single-shot`` full-field assessment of the distribution of thermal properties in large components by measuring thermal diffusivity. By applying digital image filtering, interpolation, and least-squares-estimation techniques for noise reduction, we can achieve acquisition and analysis times of minutes or less with submillimeter spatial resolution. The system developed at Argonne has been used to examine the effects of thermal shock, oxidation treatment, density variations, and variations in oxidation resistant coatings in a full array of test specimens. Subscale CFCC components with nonplanar geometries have also been studied for manufacturing-induced variations in thermal properties.

Steckenrider, J.S.; Ellingson, W.A. [Argonne National Lab., IL (United States); Rothermel, S.A. [South Dakota State Univ., Brookings, SD (United States)

1995-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal catalytic cracking" 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.


481

Concrete cover cracking with reinforcement corrosion of RC beam during chloride-induced corrosion process  

SciTech Connect (OSTI)

This paper deals with the evolution of the corrosion pattern based on two beams corroded by 14 years (beam B1CL1) and 23 years (beam B2CL1) of conservation in a chloride environment. The experimental results indicate that, at the cracking initiation stage and the first stage of cracking propagation, localized corrosion due to chloride ingress is the predominant corrosion pattern and pitting corrosion is the main factor that influences the cracking process. As corrosion cracking increases, general corrosion develops rapidly and gradually becomes predominant in the second stage of cracking propagation. A comparison between existing models and experimental results illustrates that, although Vidal et al.'s model can better predict the reinforcement corrosion of beam B1CL1 under localized corrosion, it cannot predict the corrosion of beam B2CL1 under general corrosion. Also, Rodriguez's model, derived from the general corrosion due to electrically accelerated corrosion experiments, cannot match natural chloride corrosion irrespective of whether corrosion is localized or general. Thus, for natural general corrosion in the second stage of cracking propagation, a new model based on the parameter of average steel cross-section loss is put forward to predict steel corrosion from corrosion cracking.

Zhang Ruijin, E-mail: rjzhang@mail.neu.edu.c [Modern Design and Analysis Research Institute, Northeastern University, Shenyang (China); Castel, Arnaud; Francois, Raoul [LMDC - Laboratoire Materiaux et Durabilite des Constructions, Universite de Toulouse, UPS, INSA, Toulouse (France)

2010-03-15T23:59:59.000Z

482

A displacement-based method for predicting plasticity-induced fatigue crack closure  

SciTech Connect (OSTI)

A numerical method for predicting closure and its effects on thermomechanical crack growth has been developed. A finite element model, using linear-elastic fracture mechanics shape functions, is employed to predict crack tip displacements. The effective changes in stress intensity, and therefore crack growth, are obtained from the minimum and maximum crack tip displacement predictions. When a flaw is loaded in Mode 1, a ligament of material ahead of the flaw yields, and a maximum crack tip displacement is computed. Upon unloading, plastically deformed material from prior plastic zones acts to limit the minimum displacements of the crack tip. The material is modeled as elastic-perfectly plastic. The yield strength of the material is varied based on the degree of constraint. The upper limit of constraint is a plane strain condition while the lowest constraint is a plane stress condition. The level of constraint is predicted by relating the stress intensity to the thickness of the component. Temperatures also affect yield strength, along with stiffness, and can cause the plastic zone to expand due to creep. During variable-amplitude loadings, and/or temperature changes, the irregular shape of the wake can be accommodated with this numerical procedure. The method has proven to accurately account for load interaction effects such as delayed retardation, crack arrest, initial accelerations following overloads, and the transient growth and stabilization of closure level with number of overloads.

Pawlik, M.E.; Saff, C.R.

1999-07-01T23:59:59.000Z

483

Assessment of Crack Detection in Cast Austenitic Piping Components Using Advanced Ultrasonic Methods.  

SciTech Connect (OSTI)

Studies conducted at the Pacific N¬orthwest National Laboratory (PNNL) in Richland, Washington, have focused on developing and evaluating the reliability of nondestructive examination (NDE) approaches for inspecting coarse-grained, cast stainless steel reactor components. The objective of this work is to provide information to the United States Nuclear Regulatory Commission (NRC) on the utility, effec¬tiveness and limitations of ultrasonic testing (UT) inspection techniques as related to the in-service inspec¬tion of primary system piping components in pressurized water reactors (PWRs). Cast stainless steel pipe specimens were examined that contain thermal and mechanical fatigue cracks located close to the weld roots and have inside/outside surface geometrical conditions that simulate several PWR primary piping configurations. In addition, segments of vintage centrifugally cast piping were also examined to understand inherent acoustic noise and scattering due to grain structures and determine consistency of UT responses from different locations. The advanced UT methods were applied from the outside surface of these specimens using automated scanning devices and water coupling. The low-frequency ultrasonic method employed a zone-focused, multi-incident angle inspection protocol (operating at 250-450 kHz) coupled with a synthetic aperture focusing technique (SAFT) for improved signal-to-noise and advanced imaging capabilities. The phased array approach was implemented with a modified instrument operating at 500 kHz and composite volumetric images of the specimens were generated. Re¬sults from laboratory studies for assessing detection, localization and sizing effectiveness are discussed in this paper.

Anderson, Michael T.; Crawford, Susan L.; Cumblidge, Stephen E.; Diaz, Aaron A.; Doctor, Steven R.

2007-01-01T23:59:59.000Z

484

Coal hydrogenation and deashing in ebullated bed catalytic reactor  

DOE Patents [OSTI]

An improved process for hydrogenation of coal containing ash with agglomeration and removal of ash from an ebullated bed catalytic reactor to produce deashed hydrocarbon liquid and gas products. In the process, a flowable coal-oil slurry is reacted with hydrogen in an ebullated catalyst bed reaction zone at elevated temperature and pressure conditions. The upward velocity and viscosity of the reactor liquid are controlled so that a substantial portion of the ash released from the coal is agglomerated to form larger particles in the upper portion of the reactor above the catalyst bed, from which the agglomerated ash is separately withdrawn along with adhering reaction zone liquid. The resulting hydrogenated hydrocarbon effluent material product is phase separated to remove vapor fractions, after which any ash remaining in the liquid fraction can be removed to produce substantially ash-free coal-derived liquid products.

Huibers, Derk T. A. (Pennington, NJ); Johanson, Edwin S. (Princeton, NJ)

1983-01-01T23:59:59.000Z

485

Development of a Methane Premixed Catalytic Burner for Household Applications  

Science Journals Connector (OSTI)

The catalytic combustion of methane is currently investigated in a variety of international research programs, thanks to its numerous potential applications (e.g., boilers, process heaters, reciprocating engines, gas-turbine cycles, etc.). ... At low surface heat powers (Q) and excesses of air (Ea), the combustion mostly occurs in a thin layer within the permeable panel (radiant or flameless regime, Figure 1b); the burner outlet surface (burner deck) reaches temperatures varying from 700 to 900 °C, depending on both Q and Ea values, and glows flamelessly. ... The goal is to assemble a boiler capable of coping with variable hot water requests:? from about 2?3 kW (160?240 kW/m2) for apartment heating up to 25 kW (2000 kW/m2) for sanitary purposes, so as to produce hot water with time delays compatible with the users' comfort. ...

Isotta Cerri; Guido Saracco; Francesco Geobaldo; Vito Specchia

2000-01-04T23:59:59.000Z

486

Tantalum pillard montmorillonite: II. Acidic and catalytic properties  

SciTech Connect (OSTI)

The acidic and catalytic properties of a series of Ta-PILCs synthesized with a different initial tantalum content were characterized by adsorption of gaseous probe molecules (TPD of ammonia and FTIR spectra of absorbed pyridine) and by the test reaction of 1-butanol dehydration. A large increase of acidity was noted in Ta-PILCs compared to Na-montmorillonite or tantalum oxide. Cross-linking pillars and silica layers of the clay induce stronger Lewis and new Bronsted sites. The lack of basic sites formation is evidenced by the dehydration of 1-butanol to butene selectivity (100%). The incorporation of the tantalum oxide between the montmorillonite sheets produce, within Ta-PILC, acid centers of the same nature as observed for the silicon-tantalum mixed oxides. 32 refs., 4 figs., 5 tabs.

Guiu, G.; Grange, P. [Universite Catholique de Louvain, Louvain-la-Neuve (Belgium)] [Universite Catholique de Louvain, Louvain-la-Neuve (Belgium)

1997-06-01T23:59:59.000Z

487

Ex-Situ Catalytic Fast Pyrolysis Technology Pathway  

SciTech Connect (OSTI)

In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to hydrocarbon fuels to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This pathway case investigates converting woody biomass using ex-situ catalytic fast pyrolysis followed by upgrading to gasoline , diesel and jet range blendstocks . Technical barriers and key research needs that should be pursued for this pathway to be competitive with petroleum-derived blendstocks have been identified.

Biddy, Mary J.; Dutta, Abhijit; Jones, Susanne B.; Meyer, Pimphan A.

2013-03-31T23:59:59.000Z

488

In-Situ Catalytic Fast Pyrolysis Technology Pathway  

SciTech Connect (OSTI)

In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to hydrocarbon fuels to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This pathway case investigates converting woody biomass using in-situ catalytic fast pyrolysis followed by upgrading to gasoline, diesel, and jet range blendstocks. Technical barriers and key research needs that should be pursued for this pathway to be competitive with petroleum-derived blendstocks have been identified.

Biddy, Mary J.; Dutta, Abhijit; Jones, Susanne B.; Meyer, Pimphan A.

2013-03-31T23:59:59.000Z