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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.


1

Catalytic cracking of residual petroleum fractions  

SciTech Connect (OSTI)

This paper reports on Arabian Light crude oil vacuum bottoms fractionated into five high-boiling fractions by wiped film evaporation, and the fractions subjected to catalytic cracking in a fixed-fluidized bed using a commercial equilibrium cracking catalyst. Density, aromaticity, and heteroatom content generally increased with boiling point, as did metals content except for vanadium and iron which demonstrated possible bimodal distributions. The cracking response of these fractions showed increasing yields of dry gas and coke, with decreasing gasoline yields, as a function of increasing apparent boiling point as would normally be expected. Surprisingly, however, local maxima were observed for wet gas yield and total conversion, with local minima for cycle oil and slurry yields, in the region of the 1200-1263{degrees}F (650-680{degrees}C) middle fraction. All fractions showed significant response to cracking, with coke yields generally being the only negative factor observed.

Moore, H.F.; Mayo, S.L.; Goolsby, T.L. (Research and Development Dept., Ashland Petroleum Co., Ashland, KY (US))

1991-01-01T23:59:59.000Z

2

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

3

Protocol development for evaluation of commercial catalytic cracking catalysts  

SciTech Connect (OSTI)

A complete, new set of testing protocols has been developed for qualification of catalysts for Ashland's commercial catalytic cracking units. The objective of this test development is to identify new generations of improved cracking catalysts. Prior test protocols have classically utilized microactivity (MAT) testing of steamed virgin catalysts, while more advanced methods have utilized fixed fluid bed and/or circulating pilot units. Each of these techniques, however, have been limited by their correlation to commercial operations, weaknesses in metallation and preparation of pseudo-equilibrium catalysts, and mechanical constraints on the use of heavy, vacuum bottoms-containing feedstocks. These new protocols have been baselined, compared to commercial Ashland results on known catalytic cracking catalysts, and utilized to evaluate a range of potentially new catalyst samples.

Mitchell, M.M. Jr.; Moore, H.F. (Ashland Petroleum Co., KY (USA))

1988-09-01T23:59:59.000Z

4

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...

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

Diffusion and Catalytic Cracking of 1,3,5 Tri-iso-propyl-benzene in FCC Catalysts  

E-Print Network [OSTI]

1 Diffusion and Catalytic Cracking of 1,3,5 Tri-iso- propyl-benzene in FCC Catalysts S.Al-Khattaf1 describes catalytic cracking experiments developed in a novel CREC Riser Simulator using 1,3,5-Tri-iso

Al-Khattaf, Sulaiman

7

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

8

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

9

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

10

Prediction of thermal reflection cracking in west Texas  

E-Print Network [OSTI]

for the stress intensity factor, Ck, following Barenblatt (53) is used. z 'e(')4' C = ? / k n o (3-11) where C is the distance away from crack tip and o (g) is the surface e stress inside the crack tip element, i. e. ? o is the thermal stress at the depth... of the studies being conducted on pavement temp- erature cracking have been mainly concerned with the fracture suscepti- bilityy of asphalt concrete under extremely low temperature (3, 4). Find- ings of these studies could not provide satisfactory...

Chang, Hang-Sun

1975-01-01T23:59:59.000Z

11

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

E-Print Network [OSTI]

-reinforced ceramic composites obtain high toughness is through the de- velopment of multiple matrix cracksThermal resistance of bridged cracks in fiber-reinforced ceramic composites John Dryden Department November 2000; accepted for publication 16 January 2001 The thermal resistance of a bridged matrix crack

Zok, Frank

12

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

Paris-Sud XI, Université de

13

Economics for iso-olefin production using the fluid catalytic cracking unit  

SciTech Connect (OSTI)

The Clean Air Act of 1990 requires use of oxygenates in some gasolines to improve both CO and hydrocarbon auto tailpipe emissions. Various oxygenates are currently being used by the refining industry. For the fully integrated refinery having a fluid catalytic cracking unit, the most commonly used oxygenates are methyl tertiary butyl ether (MTBE) and tertiary amyl ether (TAME). The FCC unit produces the isobutylene and iso-amylases need for manufacture of both MTBE and TAME. The economics for an assumed refinery processing scheme for several FCC cases are examined giving estimates of income and investments for each case. Up to one-third of the total gasoline pool can be made in reformulated gasoline using TAME and MTBE with the FCC unit as the sole source of feedstock. This processing route is much more economical than the alternative scheme using butane isomerization/iosbutane dehydrogenation.

McClung, R.G.; Witoshkin, A.; Bogert, D.C.; Winkler, W.S. [Englehard Corp., Iselin, NJ (United States)

1993-12-31T23:59:59.000Z

14

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

15

Demetallization of asphaltenes: Thermal and catalytic effects with small-pore catalysts  

SciTech Connect (OSTI)

Residual oil hydrotreating has become an important front end process in commercial oil upgrading schemes because of tighter environmental regulations and a continuing trend toward processing heavier crudes. At Phillips Petroleum, residual oil hydrotreating pretreates feed for heavy oil cracking (HOC) by removing sulfur, a pollutant in the HOC stack gas, and metals such as nickel and vanadium, which adversely affect the cracking catalyst and gasoline yield in the HOC. Metals in residual oil are found almost exclusively in the resin and asphaltene fractions. Research has showed that metals in the resin fraction react more rapidly than metals in the asphaltene fraction. The hydrodemetallization (HDM) reaction is known to be diffusion limited and the larger molecular size of the asphaltene molecules may explain the slower reaction rates. Richardson and Alley and Asaoka, et al. have shown a reduction in asphaltene molecular weights with thermal and catalytic processing. Reynolds and Biggs demonstrated shifts in vanadium size distributions from thermally and catalytically treated residual. Recently Savage and Javanmaridian showed theoretically that reduction in molecular sizes external to catalyst pellets increases the reaction rate by as much as the inverse of the effectiveness factor. This work attempts to extend information on how metals are removed from asphaltenes and the interaction with small-pore catalysts generally found at the back end of residual oil hydrotreaters, where they are protected from deactivation by metal deposition. The small-pore catalysts are generally high in hydrodesulfurization (HDS) activity and generally restrict the large asphaltene molecules from entering their pores and depositing metals.

Adarme, R. (Oklahoma State Univ., Stillwater, OK (United States)); Sughrue, E.L.; Johnson, M.M.; Kidd, D.R.; Phillips, M.D.; Shaw, J.E. (Phillips Petroleum Co., Bartlesville, OK (United States))

1990-08-01T23:59:59.000Z

16

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

E-Print Network [OSTI]

Effects of Matrix Cracks on the Thermal Diffusivity of a Fiber-Reinforced Ceramic Composite of Engineering Science, University of Western Ontario, London, Ontario N6A 5B9, Canada Effects of matrix cracks conductances coupled with a unit cell model for a fiber composite containing a periodic array of matrix cracks

Zok, Frank

17

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

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

thermal and gas 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...

18

Enlargement of concrete blocks of arch dams with allowance of the formation of radial thermal cracks  

SciTech Connect (OSTI)

Considerable acceleration of the construction of arch dams with the use of highly productive continuous concreting mechanisms is possible with enlargement of the blocks and allowance of the formation of thermal radial cracks in them. A theoretical analysis and the results of on-site observations show that under the effect of the hydrostatic head of water, radial joints and cracks in compressed zones of an arch dam close and the dam in these zones works as a solid dam. Thermal cracking in concrete blocks of arch dams enlarged in plan should be controlled by making radial notches to concentrate tensile stresses providing the formation of radial cracks at prescribed places and through the usual methods of thermal regulation. The block size along the face of an arch dam is then no longer limited by the condition of crack resistance but is determined by the rate of concreting. The technical and economic effects from concreting arch dams are cited.

Verbetskii, G.P.; Chogovadze, G.I.; Daneliya, A.I.

1988-04-01T23:59:59.000Z

19

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

20

A lightweight three-phase Fluid Catalytic Cracking riser model for real-time simulation and interactive three-dimensional visualization  

E-Print Network [OSTI]

physical model and a fast numerical solver are proposed for the rendering of fluid catalytic cracking (FCC) dynamics in the riser cylinder reactor part of the FCC unit. For Real Time requirements, a trade, privileged paths for the gas phase, etc. Of course, the rendering is purely qualitative, but accurate enough

Paris-Sud XI, Université de

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

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

22

Coating of a stainless steel tube-wall catalytic reactor with thermally treated polysiloxane thick films  

E-Print Network [OSTI]

Coating of a stainless steel tube-wall catalytic reactor with thermally treated polysiloxane thick stainless steel by plasma assisted chemical vapour deposition process. Thicknesses up to 10µm were developed glass-like silicon oxide but cannot be related to an amorphous silica structure. At 1273K the steel

Paris-Sud XI, Université de

23

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

24

Roles of grain boundaries in cleavage cracking and thermal crack arrest experiments in iron-silicon alloy  

E-Print Network [OSTI]

High-angle grain boundaries in steel offer an important resistance to the propagation of cleavage cracks that affects the fracture toughness and can modulate the ductile-to-brittle transition temperature of fracture downward. ...

Qiao, Yu, 1972-

2002-01-01T23:59:59.000Z

25

Gamma prime embrittlement and thermal fatigue cracking of a hydrogen reformer burner end  

SciTech Connect (OSTI)

An investigation into the premature failure of an Alloy 800HT (UNS N08811) oxygen-gas mixer water jacketed end is discussed. Detailed metallurgical analyses showed that gamma prime [Ni{sub 3} (Al, Ti)] embrittlement and thermal fatigue cracking led to eventual leakage. The reduced lif e of the Alloy 800HT (UNS N08811) replacement (problems after only a year) was traced to its higher Al + Ti content (1.1%) compared to Alloy 800H (0.6% Al + Ti) which lasted over two years. While higher aluminum and titanium levels improve high temperature creep and stress rupture properties, both are sigma formers and, at levels > 0.6%, tend to form gamma prime with nickel. The choice of alternative metallurgies requires careful considerations of physical, mechanical and thermal properties as well as an understanding of complex stresses and stress distributions.

Dias, O.C.; Mack, N.C. [Amoco Oil Co., Texas City, TX (United States)

1994-12-31T23:59:59.000Z

26

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.

27

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

E-Print Network [OSTI]

The development of cracks in Portland Cement Concrete (PCC) and Grout has become a problem of rising concern in a country with an aging infrastructure. A detailed understanding of the causes as well as the behavior of these cracks is vital...

Spencer, Matthew T

2013-02-06T23:59:59.000Z

28

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

29

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

30

Non-thermal Plasma-Assisted Catalytic NOx Reduction over Ba-Y,FAU: The  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the Contributions andDataNationalNewportBig Eddy ArcheologicalSolar Thermal Page 1Effect

31

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

32

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

33

Plasma-assisted catalytic reduction system  

DOE Patents [OSTI]

Non-thermal plasma gas treatment is combined with selective catalytic reduction to enhance NO{sub x} reduction in oxygen-rich vehicle engine exhausts. 8 figs.

Vogtlin, G.E.; Merritt, B.T.; Hsiao, M.C.; Wallman, P.H.; Penetrante, B.M.

1998-01-27T23:59:59.000Z

34

The complexity of catalytically "cracking" cellulose | EMSL  

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

chain length affects oxygen's departure in key reaction for building bio-fuels Replacing fossil fuels in industrial applications could reduce economic, environmental and security...

35

Carbenium ion intermediates in catalytic cracking  

E-Print Network [OSTI]

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... &Vdk' 800 me )OO 0 - 100 -200 PPll Fig. 5 l~C CPNAS spectrum of tri-phenylmethyl chloride adsorbed on silica-alumina. 21 times, techniques which allow for moderately higher reso- lution are required. One such technique is combined cross...

Zardkoohi, Minoo

1987-01-01T23:59:59.000Z

36

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

37

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

38

Creep failure of cracking heater at a petrochemical plant  

SciTech Connect (OSTI)

After two and half years of operation, a bend tube in a cracking heater at an ethylene plant failed due to creep cracking. Creep damage occurred as a result of metallurgical instability including coarsening of carbides that caused softening and initiation of voids or wedge-type intergranular cracks. This was accelerated due to increasing inner surface temperature during decoking process. Thermal fatigue contributed to the failure as a result of temperature variations due to several shutdown-startup operations. To minimize such failure in futures, periodic inspection to monitor crack formation was scheduled. Nondestructive tests including dye penetrant test for surface cracking and radiographic test for internal crack were implemented.

El-Batahgy, A. [Welding Research Department, Central, Metallurgical R and D Institute, Cairo (Egypt)]. E-mail: elbatahgy@yahoo.com; Zaghloul, B. [Central Metallurgical R and D Institute, P.O. Box: 87 Helwan, Cairo (Egypt)

2005-03-15T23:59:59.000Z

39

Catalytic reduction system for oxygen-rich exhaust  

DOE Patents [OSTI]

Non-thermal plasma gas treatment is combined with selective catalytic reduction to enhance NO{sub x} reduction in oxygen-rich vehicle engine exhausts. 8 figs.

Vogtlin, G.E.; Merritt, B.T.; Hsiao, M.C.; Wallman, P.H.; Penetrante, B.M.

1999-04-13T23:59:59.000Z

40

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

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

Catalytic Coherence  

E-Print Network [OSTI]

Due to 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 Aberg

2014-10-20T23:59:59.000Z

42

Crack coalescence in granite  

E-Print Network [OSTI]

This thesis experimentally investigates crack coalescence in prismatic Barre Granite specimens with two pre-cut, open flaws under uniaxial compression. Using a high-speed video system, crack initiation, propagation, and ...

Miller, James Thomas, Ph. D. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

43

Hydrocarbon cracking with yttrium exchanged zeolite y catalyst  

SciTech Connect (OSTI)

A process is described for cracking a gas oil boiling range hydrocarbon feedstock comprising the step of contacting the feedstock in a catalytic cracking zone under catalytic cracking conditions to produce convulsion products comprising gasoline with a catalyst composition. The process comprises: a Y crystalline aluminosilicate zeolite, having the structure of faujasite and having uniform pore diameters and a silica to alumina mole ratio of at least about 5; an inorganic oxide matrix; and the zeolite having been ion exchanged with a mixture of rare earths prior to compositing with the matrix; and the zeolite having been subsequently further ion exchanged with yttrium following compositing with the matrix, whereby the catalyst composition contains 0.30 to 3.0 wt% yttrium.

Lochow, C.F.; Kovacs, D.B.

1987-05-12T23:59:59.000Z

44

Application of the cracked pipe element to creep crack growth prediction  

SciTech Connect (OSTI)

The modification of a computer code for leak before break analysis is very briefly described. The CASTEM2000 code was developed for ductile fracture assessment of piping systems with postulated circumferential through-wall cracks under static or dynamic loading. The modification extends the capabilities of the cracked pipe element to the determination of fracture parameters under creep conditions (C*, {phi}c and {Delta}c). The model has the advantage of evaluating significant secondary effects, such as those from thermal loading.

Brochard, J.; Charras, T.

1997-04-01T23:59:59.000Z

45

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

46

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

47

Application of the cracked pipe element to creep crack growth prediction  

SciTech Connect (OSTI)

Modifications to a computer code for ductile fracture assessment of piping systems with postulated circumferential through-wall cracks under static or dynamic loading are very briefly described. The modifications extend the capabilities of the CASTEM2000 code to the determination of fracture parameters under creep conditions. The main advantage of the approach is that thermal loads can be evaluated as secondary stresses. The code is applicable to piping systems for which crack propagation predictions differ significantly depending on whether thermal stresses are considered as primary or secondary stresses.

Brochard, J.; Charras, T. [C.E.A.-C.E.-Saclay DRN/DMT, Gif Sur Yvette (France); Ghoudi, M. [C.E.A.-C.E.-Saclay, Gif Sur Yvette (France)

1997-04-01T23:59:59.000Z

48

Crack isobutane for isobutylene  

SciTech Connect (OSTI)

This paper describes the coastal isobutane cracking process which cracks isobutane under controlled conditions in the presence of steam utilizing efficient tubular furnaces and produces high propylene and isobutylene yields. The authors list the options to which this process lends itself.

Soudek, M. (Coastal States Management Corp., Houston, TX (US)); Lacatena, J.J. (Foster Wheeler USA Corp., Clinton, NJ (US))

1990-05-01T23:59:59.000Z

49

Cracking blends of gas oil and residual oil  

SciTech Connect (OSTI)

In a catalytic cracking process unit wherein a gas oil feed is cracked in a cracking zone at an elevated temperature in the presence of a cracking catalyst, the cracking catalyst is regenerated in a regeneration zone by burning coke of the catalyst, and catalyst is circulated between the cracking zone and the regeneration zone. The improvement is described for obtaining a naphtha product of improved octane number comprising introducing sufficient of a nickel and vanadium metals-containing heavy feedstock with the gas oil feed introduced into the cracking zone to deposit nickel and vanadium metals on the catalyst and raise the nickel and metals-content of the catalyst to a level ranging from about 1500 to about 6000 parts per million of the metals expressed as equivalent nickel, based on the weight of the catalyst, and maintaining the nickel and vanadium metals level on the catalyst by withdrawing high nickel and vanadium metals containing catalyst and adding low nickel and vanadium metals-containing catalyst to the regeneration zone.

Myers, G.D.

1988-03-01T23:59:59.000Z

50

Energy Recovery System for Fluid Catalytic Cracking Units  

E-Print Network [OSTI]

to the regenerator, and produces electricity for export. The sensible heat in the exhaust from the expander is further recovered in a waste heat boiler. A typical expander train consists of a hot gas expander, an air compressor, an auxiliary steam turbine for start...

Wen, H.; Lou, S. C.

1982-01-01T23:59:59.000Z

51

Fluidic Catalytic Cracking Power Recovery Dynamic Computer Simulation  

E-Print Network [OSTI]

Fluidic Cat Crackers (FCC) using the catalyst regeneration cycle are candidates for more power efficient operation by the use of high temperature dirty gas expanders. In a previous paper, a computer simulation was described for the steady state...

Samurin, N. A.

1980-01-01T23:59:59.000Z

52

Energy Conservation Revamps in Fluid Catalytic Cracking Systems  

E-Print Network [OSTI]

in the vapor recovery unit. By selecting the proper location and rates of side pump around streams, heat available in the main column can be used to reboil most or all of the VRU towers. Revamps of this type may be undertaken as stand alone energy conservation...

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

1984-01-01T23:59:59.000Z

53

The complexity of catalytically "cracking" cellulose | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus TomAboutManusScienceThe Life ofSciencetheEnergy The

54

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

55

Catalytic co-processing of coal with bitumen and bitumen derived liquids  

SciTech Connect (OSTI)

Experimental studies on the co-processing of coal with bitumen and bitumen derived liquids are described. A subbituminous coal was coprocessed with Athabasca bitumen and its various liquid fractions in a batch autoclave under hydrogen pressure at reaction temperatures varying from 400 to 440{degrees}C. Both thermal and catalytic coprocessing experiments were conducted. The catalysts used were molten halide type and included ZnCl{sub 2}, MoCl{sub 5}, KCl, CuCl, and SnCl{sub 2}. Higher reaction temperature resulted in higher conversion of asphaltenes into both maltenes and coke and gases. As a result the H/C atomic ratio of the unconverted asphaltenes decreased with temperature. Higher reaction time on the other hand allowed maltenes to be converted to asphaltenes. While all the catalysts tested had catalytic effects on asphaltene conversion, MoCl{sub 5} was found to provide the highest conversion of asphaltenes due to its ability to hydrogenate the radicals formed due to asphaltene cracking. Processing of coal with bitumen derived liquids provided higher yields than those obtained with virgin bitumen. The H/C ratios were also higher for the products obtained with bitumen derived liquids.

Chakma, A.; Zaman, J. [Univ. of Calgary, Alberta (Canada)

1993-12-31T23:59:59.000Z

56

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

57

Determination of crack morphology parameters from service failures for leak-rate analyses  

SciTech Connect (OSTI)

In leak-rate analyses described in the literature, the crack morphology parameters are typically not well agreed upon by different investigators. This paper presents results on a review of crack morphology parameters determined from examination of service induced cracks. Service induced cracks were found to have a much more tortuous flow path than laboratory induced cracks due to crack branching associated with the service induced cracks. Several new parameters such as local and global surface roughnesses, as well as local and global number of turns were identified. The effect of each of these parameters are dependent on the crack-opening displacement. Additionally, the crack path is typically assumed to be straight through the pipe thickness, but the service data show that the flow path can be longer due to the crack following a fusion line, and/or the number of turns, where the number of turns in the past were included as a pressure drop term due to the turns, but not the longer flow path length. These parameters were statistically evaluated for fatigue cracks in air, corrosion-fatigue, IGSCC, and thermal fatigue cracks. A refined version of the SQUIRT leak-rate code was developed to account for these variables. Sample calculations are provided in this paper that show how the crack size can vary for a given leak rate and the statistical variation of the crack morphology parameters.

Wilkowski, G.; Ghadiali, N.; Paul, D. [Battelle Memorial Institute, Columbus, OH (United States)] [and others

1997-04-01T23:59:59.000Z

58

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

59

Saber's heavy oil cracking refinery project  

SciTech Connect (OSTI)

Perhaps more than any other industry, petroleum refining has been subjected to the radical swings in business and political climates of the past several decades. Because of the huge investments and long lead times to construct refining facilities, stable government policies, predictable petroleum prices, secure feedstock supplies and markets, and reliable cost estimates are necessary ingredients to effectively plan new refinery projects. However, over the past ten years the political and economic climates have provided anything but these conditions. Yet, refiners have demonstrated a willingness to undertake risks by continuing to expand and modernize their refineries. The refining business -- just as most businesses -- responds to economic incentives. These incentives, when present, result in new technology and capacity additions. In the 1940's, significant technology advances were commercialized to refine higher-octane motor gasolines. Such processes as continuous catalytic cracking (Houdry Process Corporation), fluid catalytic cracking (Standard Oil Development Company), HF alkylation (UOP and Phillips Petroleum Company), and catalytic reforming (UOP) began to supply a growing gasoline market, generated from the war effort and the ever increasing numbers of automobiles on the road. The post-war economy of the 1950's and 1960's further escalated demand for refined products, products which had to meet higher performance specifications and be produced from a wider range of raw materials. The refining industry met the challenge by introducing hydro-processing technology, such as hydrocracking developed in 1960. But, the era must be characterized by the large crude processing capacity additions, required to meet demand from the rapidly expanding U.S. economy. In 1950, refining capacity was 6.2 million BPD. By 1970, capacity had grown to 11.9 million BPD, an increase of 91%.

Benefield, C.S.; Glasscock, W.L.

1983-03-01T23:59:59.000Z

60

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

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

Selective dehydrogenation of propane over novel catalytic materials  

SciTech Connect (OSTI)

The conversion of small alkanes into alkenes represents an important chemical processing area; ethylene and propylene are the two most important organic chemicals manufactured in the U.S. These chemicals are currently manufactured by steam cracking of ethane and propane, an extremely energy intensive, nonselective process. The development of catalytic technologies (e.g., selective dehydrogenation) that can be used to produce ethylene and propylene from ethane and propane with greater selectivity and lower energy consumption than steam cracking will have a major impact on the chemical processing industry. This report details a study of two novel catalytic materials for the selective dehydrogenation of propane: Cr supported on hydrous titanium oxide ion-exchangers, and Pt nanoparticles encapsulated in silica and alumina aerogel and xerogel matrices.

Sault, A.G.; Boespflug, E.P.; Martino, A.; Kawola, J.S.

1998-02-01T23:59:59.000Z

62

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

63

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

64

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

65

Hydrocarbon cracking catalyst  

SciTech Connect (OSTI)

This patent describes a catalyst composition for cracking hydrocarbons to maximize gasoline comprising: rare earth exchanged ''Y'' crystalline faujasite dispersed in a clay containing matrix material; and which has been subsequently further ion exchanged to contain 0.20 to 3.0 wt% yttrium, calculated as the oxide, whereby the yttrium is chemically combined in the catalyst composition.

Lochow, C.F.; Kovacs, D.B.

1988-12-27T23:59:59.000Z

66

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

67

Integrated Biomass Gasification with Catalytic Partial Oxidation for Selective Tar Conversion  

SciTech Connect (OSTI)

Biomass gasification is a flexible and efficient way of utilizing widely available domestic renewable resources. Syngas from biomass has the potential for biofuels production, which will enhance energy security and environmental benefits. Additionally, with the successful development of low Btu fuel engines (e.g. GE Jenbacher engines), syngas from biomass can be efficiently used for power/heat co-generation. However, biomass gasification has not been widely commercialized because of a number of technical/economic issues related to gasifier design and syngas cleanup. Biomass gasification, due to its scale limitation, cannot afford to use pure oxygen as the gasification agent that used in coal gasification. Because, it uses air instead of oxygen, the biomass gasification temperature is much lower than well-understood coal gasification. The low temperature leads to a lot of tar formation and the tar can gum up the downstream equipment. Thus, the biomass gasification tar removal is a critical technology challenge for all types of biomass gasifiers. This USDA/DOE funded program (award number: DE-FG36-O8GO18085) aims to develop an advanced catalytic tar conversion system that can economically and efficiently convert tar into useful light gases (such as syngas) for downstream fuel synthesis or power generation. This program has been executed by GE Global Research in Irvine, CA, in collaboration with Professor Lanny Schmidt's group at the University of Minnesota (UoMn). Biomass gasification produces a raw syngas stream containing H2, CO, CO2, H2O, CH4 and other hydrocarbons, tars, char, and ash. Tars are defined as organic compounds that are condensable at room temperature and are assumed to be largely aromatic. Downstream units in biomass gasification such as gas engine, turbine or fuel synthesis reactors require stringent control in syngas quality, especially tar content to avoid plugging (gum) of downstream equipment. Tar- and ash-free syngas streams are a critical requirement for commercial deployment of biomass-based power/heat co-generation and biofuels production. There are several commonly used syngas clean-up technologies: (1) Syngas cooling and water scrubbing has been commercially proven but efficiency is low and it is only effective at small scales. This route is accompanied with troublesome wastewater treatment. (2) The tar filtration method requires frequent filter replacement and solid residue treatment, leading to high operation and capital costs. (3) Thermal destruction typically operates at temperatures higher than 1000oC. It has slow kinetics and potential soot formation issues. The system is expensive and materials are not reliable at high temperatures. (4) In-bed cracking catalysts show rapid deactivation, with durability to be demonstrated. (5) External catalytic cracking or steam reforming has low thermal efficiency and is faced with problematic catalyst coking. Under this program, catalytic partial oxidation (CPO) is being evaluated for syngas tar clean-up in biomass gasification. The CPO reaction is exothermic, implying that no external heat is needed and the system is of high thermal efficiency. CPO is capable of processing large gas volume, indicating a very compact catalyst bed and a low reactor cost. Instead of traditional physical removal of tar, the CPO concept converts tar into useful light gases (eg. CO, H2, CH4). This eliminates waste treatment and disposal requirements. All those advantages make the CPO catalytic tar conversion system a viable solution for biomass gasification downstream gas clean-up. This program was conducted from October 1 2008 to February 28 2011 and divided into five major tasks. - Task A: Perform conceptual design and conduct preliminary system and economic analysis (Q1 2009 ~ Q2 2009) - Task B: Biomass gasification tests, product characterization, and CPO tar conversion catalyst preparation. This task will be conducted after completing process design and system economics analysis. Major milestones include identification of syngas cleaning requirements for proposed system

Zhang, Lingzhi; Wei, Wei; Manke, Jeff; Vazquez, Arturo; Thompson, Jeff; Thompson, Mark

2011-05-28T23:59:59.000Z

68

Steam reformer with catalytic combustor  

DOE Patents [OSTI]

A steam reformer is disclosed having an annular steam reforming catalyst bed formed by concentric cylinders and having a catalytic combustor located at the center of the innermost cylinder. Fuel is fed into the interior of the catalytic combustor and air is directed at the top of the combustor, creating a catalytic reaction which provides sufficient heat so as to maintain the catalytic reaction in the steam reforming catalyst bed. Alternatively, air is fed into the interior of the catalytic combustor and a fuel mixture is directed at the top. The catalytic combustor provides enhanced radiant and convective heat transfer to the reformer catalyst bed.

Voecks, Gerald E. (La Crescenta, CA)

1990-03-20T23:59:59.000Z

69

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

70

Development of reduced crude cracking catalysts  

SciTech Connect (OSTI)

In 1974 OPEC imposed an embargo on oil to the United States and caused a rapid rise in the price of a barrel of oil. At the time of the embargo, Ashland imported a considerable portion of its oil from the Middle East, thus raising the question of oil availability. As the problem increased in severity, Messrs. George Meyer, Oliver Zandona and Llyod Busch, began to explore alternative ways of squeezing more product from a given barrel of crude. After considering many alternatives, they arrived at the innovative thought that it might be possible to catalytically crack the 1050{degree}F plus fraction of the barrel directly to gasoline which would in effect, give them an additional volume of crude oil. Also, if vacuum fractionation were eliminated and if the entire 650{degree}F plus (reduced crude) portion of the barrel processed, this would further reduce operating costs. With these objectives and some new process innovations in mind, they began reduced crude cracking experimentation in a small 12,000 B/D FCC operating unit at Louisville. It was from these goals, concepts and a small operating unit, that the RCC process was born.

Hettinger, W.P. Jr. (Ashland Petroleum Company, KY (USA))

1987-08-01T23:59:59.000Z

71

Catalytic coal liquefaction process  

DOE Patents [OSTI]

An improved process for catalytic solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a solvent comprises using as catalyst a mixture of a 1,2- or 1,4-quinone and an alkaline compound, selected from ammonium, alkali metal, and alkaline earth metal oxides, hydroxides or salts of weak acids. 1 fig.

Garg, D.; Sunder, S.

1986-12-02T23:59:59.000Z

72

Catalytic coal liquefaction process  

DOE Patents [OSTI]

An improved process for catalytic solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a solvent comprises using as catalyst a mixture of a 1,2- or 1,4-quinone and an alkaline compound, selected from ammonium, alkali metal, and alkaline earth metal oxides, hydroxides or salts of weak acids.

Garg, Diwakar (Macungie, PA); Sunder, Swaminathan (Allentown, PA)

1986-01-01T23:59:59.000Z

73

A Photosynthetic Hydrogel for Catalytic Hydrogen Production ...  

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

A Photosynthetic Hydrogel for Catalytic Hydrogen Production Home > Research > ANSER Research Highlights > A Photosynthetic Hydrogel for Catalytic Hydrogen Production...

74

Causes and solutions for cracking of coextruded and weld overlay floor tubes in black liquor recovery boilers  

SciTech Connect (OSTI)

Cracking of coextruded, black liquor recovery boiler floor tubes is both a safety and an economic issue to mill operators. In an effort to determine the cause of the cracking and to identify a solution, extensive studies, described in this and three accompanying papers, are being conducted. In this paper, results of studies to characterize both the cracking and the chemical and thermal environment are reported. Based on the results described in this series of papers, a possible mechanism is presented and means to lessen the likelihood of cracking or to totally avoid cracking of floor tubes are offered.

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

1998-09-01T23:59:59.000Z

75

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

76

Shrinkage - cracking characteristics of structural lightweight concrete  

E-Print Network [OSTI]

'P'D. ) FIGURE 4-14 Cracking as Indi. cat d by Nater Loss PACE IO 5-1 Thermal Expansion Correction by Emtrspolation /7 LZST OP TAELES TAELE Environments 35 Test. ing Program. Statistical Data Direct Tensile Specim n Data 59 4-3 Comparison of Selected.... Cement contents of 5, 0, 6. 0 ind 6. 5 i a~n. , /ci-hie yorri were used. Unrestraineii volume changes wcr liaaoi - . . i o! standard type specimens (3 x 3 x i 1. 25 . in, ) . Craciring i'!ali!ai. cd ns thi! number of ccac!. s occurring on a s, ~ i...

McKeen, Robert Gordon

1969-01-01T23:59:59.000Z

77

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

78

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

79

Catalytic hydrodesulfurization of bitumen  

SciTech Connect (OSTI)

Investigations of the catalytic hydrodesulfurization of Venezuela bitumen and its water emulsion (Orimulsion) were carried out. This material contained a large amount of sulfur and organometallics, such as vanadium and nickel compounds. A variety of nickel and molybdenum catalysts were prepared. These, as well as two commercial catalysts, were tested with Orimulsion and vacuum-dried, pentane-insoluble and soluble bitumen. Catalytic hydrotreatment removed up to 75% of sulfur from the bitumen. Hydrodesulfurization was found to be affected by reaction temperature, reaction time, catalyst, and feed material. Moisture-free bitumen and a pentane-soluble bitumen fraction were desulfurized more effectively than Orimulsion. Zeolite-based catalysts gave higher desulfurization than synthetic clay catalysts.

Sharma, R.K.; Olson, E.S. [Univ. of North Dakota, Grand Forks, ND (United States)

1995-12-31T23:59:59.000Z

80

Concentric catalytic combustor  

DOE Patents [OSTI]

A catalytic combustor (28) includes a tubular pressure boundary element (90) having a longitudinal flow axis (e.g., 56) separating a first portion (94) of a first fluid flow (e.g., 24) from a second portion (95) of the first fluid flow. The pressure boundary element includes a wall (96) having a plurality of separate longitudinally oriented flow paths (98) annularly disposed within the wall and conducting respective portions (100, 101) of a second fluid flow (e.g., 26) therethrough. A catalytic material (32) is disposed on a surface (e.g., 102, 103) of the pressure boundary element exposed to at least one of the first and second portions of the first fluid flow.

Bruck, Gerald J. (Oviedo, FL); Laster, Walter R. (Oviedo, FL)

2009-03-24T23:59:59.000Z

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

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

82

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

83

Catalytic reforming methods  

DOE Patents [OSTI]

A catalytic reforming method is disclosed herein. The method includes sequentially supplying a plurality of feedstocks of variable compositions to a reformer. The method further includes adding a respective predetermined co-reactant to each of the plurality of feedstocks to obtain a substantially constant output from the reformer for the plurality of feedstocks. The respective predetermined co-reactant is based on a C/H/O atomic composition for a respective one of the plurality of feedstocks and a predetermined C/H/O atomic composition for the substantially constant output.

Tadd, Andrew R; Schwank, Johannes

2013-05-14T23:59:59.000Z

84

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

85

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

86

Catalytic hydrodesulfurization of bitumen  

SciTech Connect (OSTI)

Investigations of the catalytic hydrodesulfurization of Venezuela bitumen and its water-emulsion (Orimulsion) were carried out. A variety of catalysts were prepared and some impregnated with molybdenum and sulfided. These and two commercial catalysts were tested with Orimulsion, vacuum-dried Orimulsion, and pentane-insoluble and soluble Orimulsion. Hydrotreatment of feed material was done in a 15-mL tube reactor using a variety of catalysts at 390{degrees}C under an initial 1000-psi hydrogen pressure with a reaction time of 1-3 hours. The hydrotreated products were analyzed by total sulfur analysis. Catalytic hydrotreatment removed up to 75% of sulfur from the bitumen. Nickel and/or molybdenum impregnation on various supports promoted sulfur removal from Orimulsion. Hydrodesulfurization was found to be affected by reaction temperature, reaction time, catalyst, and feed material. A moisture-free bitumen and a pentane-soluble bitumen fraction were desulfurized more effectively than Orimulsion. Zeolite-based catalysts gave higher desulfurization than synthetic clay catalysts or commercial AMOCAT and HDN catalysts.

Sharma, R.K.; Olson, E.S. [Univ. of North Dakota, Grand Forks, ND (United States)

1995-12-31T23:59:59.000Z

87

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

88

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

89

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

90

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

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

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

91

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

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

Preparation, Characterization, and Catalytic Properties of Tungsten Trioxide Cyclic Trimers on FeO(111)Pt(111). Preparation, Characterization, and Catalytic Properties of Tungsten...

92

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

93

Progressive flow cracking of coal/oil mixtures with high metals content catalyst  

SciTech Connect (OSTI)

This patent describes a process for economically producing liquid fuel products at least partly from coal. It comprises: introducing a progressive flow catalytic cracking zone a charge stock comprising a pumpable mixture of solid, particulate coal and carbo-metallic oil and forming within the zone a stream having a linear velocity of at least about 25 feet per second. The stream comprising the charge stock and a hydrocarbon zeolite cracking catalyst promoting dehydrogenation of the charge stock; forming mobile hydrogen within the zone by the dehydrogenation; introducing the mobile hydrogen into the stream by dehydrogenation of the charge stock in the absence of added molecular hydrogen, thereby producing liquid products from the charge stock while laying down coke on the hydrocarbon cracking catalyst in the range of about 0.3% to about 3% and thereby producing spent catalyst; separating from the spent catalyst the liquid products.

Zandona, O.J.

1989-10-10T23:59:59.000Z

94

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

95

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

96

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

97

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

98

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

1949-01-01T23:59:59.000Z

99

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

100

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

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

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

102

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

103

Cracking Resistance of Asphalt Rubber Mix Versus  

E-Print Network [OSTI]

. crack length curve for KR #12;Load vs. CMOD 0.0 0.5 1.0 1.5 2.0 Crack mouth opening, mm 0 500 1000 1500 non-linear fracture mechanics ·Compliance approach ·R-Curve approach #12;Conventional Fatigue Testing factor R-Curve approach Resistance to initiation & growth of cracks Evaluates fracture toughness

Mobasher, Barzin

104

Original article Stem cracks in Norway spruce  

E-Print Network [OSTI]

Original article Stem cracks in Norway spruce in southern Scandinavia: causes and consequences Garpenberg, Sweden (Received 1st September 1992; accepted 17 June 1993) Summary — Stem cracks in Norway;INTRODUCTION Background During this century, the widespread crack- ing of Norway spruce (Picea abies L Karst

Boyer, Edmond

105

Ashland Oil Inc. has new heavy oil cracking technology  

SciTech Connect (OSTI)

Ashland's new ''Reduced Crude Conversion'' is a fluid catalytic cracking process that permits more efficient use of the bottoms of the crude barrel, including the production of a given amount of gasoline from 20% less crude. Gasoline yields go from 49.8% for Arabian light crudes to 56.9% for Murban crudes. The new process, details of which have not been revealed, operates at ''high'' temperatures and about 1 atm; requires no feed hydrogen (and therefore, according to Ashland, compares favorably with hydrocracking); is not inhibited by catalyst poisons such as nickel and vanadium, even though these metals might adhere to the proprietary catalyst; and probably uses a zeolite catalyst. Ashland is planning a $70 million, 40,000 bbl/day unit which is scheduled to go on stream in 1982 at its Catlettsburg, Ky., refinery.

Not Available

1980-04-21T23:59:59.000Z

106

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

107

Environmentally assisted cracking of LWR materials  

SciTech Connect (OSTI)

Research on environmentally assisted cracking (EAC) of light water reactor materials has focused on (a) fatigue initiation in pressure vessel and piping steels, (b) crack growth in cast duplex and austenitic stainless steels (SSs), (c) irradiation-assisted stress corrosion cracking (IASCC) of austenitic SSs, and (d) EAC in high- nickel alloys. The effect of strain rate during different portions of the loading cycle on fatigue life of carbon and low-alloy steels in 289{degree}C water was determined. Crack growth studies on wrought and cast SSs have been completed. The effect of dissolved-oxygen concentration in high-purity water on IASCC of irradiated Type 304 SS was investigated and trace elements in the steel that increase susceptibility to intergranular cracking were identified. Preliminary results were obtained on crack growth rates of high-nickel alloys in water that contains a wide range of dissolved oxygen and hydrogen concentrations at 289 and 320{degree}C. The program on Environmentally Assisted Cracking of Light Water Reactor Materials is currently focused on four tasks: fatigue initiation in pressure vessel and piping steels, fatigue and environmentally assisted crack growth in cast duplex and austenitic SS, irradiation-assisted stress corrosion cracking of austenitic SSs, and environmentally assisted crack growth in high-nickel alloys. Measurements of corrosion-fatigue crack growth rates (CGRs) of wrought and cast stainless steels has been essentially completed. Recent progress in these areas is outlined in the following sections.

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

1995-12-01T23:59:59.000Z

108

Catalytic two-stage coal hydrogenation and hydroconversion process  

DOE Patents [OSTI]

A process for two-stage catalytic hydrogenation and liquefaction of coal to produce increased yields of low-boiling hydrocarbon liquid and gas products. In the process, the particulate coal is slurried with a process-derived liquid solvent and fed at temperature below about 650.degree. F. into a first stage catalytic reaction zone operated at conditions which promote controlled rate liquefaction of the coal, while simultaneously hydrogenating the hydrocarbon recycle oils at conditions favoring hydrogenation reactions. The first stage reactor is maintained at 650.degree.-800.degree. F. temperature, 1000-4000 psig hydrogen partial pressure, and 10-60 lb coal/hr/ft.sup.3 reactor space velocity. The partially hydrogenated material from the first stage reaction zone is passed directly to the close-coupled second stage catalytic reaction zone maintained at a temperature at least about 25.degree. F. higher than for the first stage reactor and within a range of 750.degree.-875.degree. F. temperature for further hydrogenation and thermal hydroconversion reactions. By this process, the coal feed is successively catalytically hydrogenated and hydroconverted at selected conditions, which results in significantly increased yields of desirable low-boiling hydrocarbon liquid products and minimal production of undesirable residuum and unconverted coal and hydrocarbon gases, with use of less energy to obtain the low molecular weight products, while catalyst life is substantially increased.

MacArthur, James B. (Denville, NJ); McLean, Joseph B. (So. Somerville, NJ); Comolli, Alfred G. (Yardley, PA)

1989-01-01T23:59:59.000Z

109

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,...

110

Bifunctional Catalysts for the Selective Catalytic Reduction...  

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

Reduction (DEER) Conference Presentation: Argonne National Laboratory 2004deermarshall.pdf More Documents & Publications Bifunctional Catalysts for the Selective Catalytic...

111

Cascading of fluid cracking catalysts  

SciTech Connect (OSTI)

A process is described for conversion of hydrocarbon feedstocks by cascading a cracking catalyst containing zeolite in an acidic matrix from one hydrocarbon processing unit to another, wherein there are at least three different interconnected hydrocarbon processing units comprising a first unit having a regeneration zone and a riser zone, a second unit having having a regeneration zone and a riser zone, and a third unit having a riser zone and a regeneration zone, each unit having different processing conditions.

Kovach, S.M.; Miller, C.B.

1986-05-27T23:59:59.000Z

112

INTEGRAL CATALYTIC COMBUSTION/FUEL REFORMING  

E-Print Network [OSTI]

INTEGRAL CATALYTIC COMBUSTION/FUEL REFORMING FOR GAS TURBINE Prepared For: California Energy REPORT (FAR) INTEGRAL CATALYTIC COMBUSTION/FUEL REFORMING FOR GAS TURBINE CYCLES EISG AWARDEE University://www.energy.ca.gov/research/index.html. #12;Page 1 Integral Catalytic Combustion/Fuel Reforming for Gas Turbine Cycles EISG Grant # 99

113

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

114

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

115

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.

116

Microstructural development and solidification cracking susceptibility of Cu deposits on steel: Part I  

E-Print Network [OSTI]

Microstructural development and solidification cracking susceptibility of Cu deposits on steel industry is interested in depositing Cu onto steel using direct metal deposition techniques in order to improve thermal management of mold dies manufactured from steel alloys. However, Cu is a known promoter

DuPont, John N.

117

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.

118

Methodology for predicting asphalt concrete overlay life against reflection cracking  

E-Print Network [OSTI]

of thermal expansion = change in temperature E K - (so gT) vc/h F3(c/h) +(I-u ) By defining, !40) (41) Jc/h F3(c/h) T Kt (42 ) 29 ~Summa r The proper variables to be used in a design equation and the form of the equation to be used is best... obtained are presented in this chapter. The stress intensity factor computations were carr1ed out for different crack-tip positions and for different levels of aggregate interlock act1on. These results were obtained for each of the three mechanisms...

Jayawickrama, Priyantha Warnasuriya

1985-01-01T23:59:59.000Z

119

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

120

Crack stability analysis of low alloy steel primary coolant pipe  

SciTech Connect (OSTI)

At present, cast duplex stainless steel has been used for the primary coolant piping of PWRs in Japan and joints of dissimilar material have been applied for welding to reactor vessels and steam generators. For the primary coolant piping of the next APWR plants, application of low alloy steel that results in designing main loops with the same material is being studied. It means that there is no need to weld low alloy steel with stainless steel and that makes it possible to reduce the welding length. Attenuation of Ultra Sonic Wave Intensity is lower for low alloy steel than for stainless steel and they have advantageous inspection characteristics. In addition to that, the thermal expansion rate is smaller for low alloy steel than for stainless steel. In consideration of the above features of low alloy steel, the overall reliability of primary coolant piping is expected to be improved. Therefore, for the evaluation of crack stability of low alloy steel piping to be applied for primary loops, elastic-plastic future mechanics analysis was performed by means of a three-dimensioned FEM. The evaluation results for the low alloy steel pipings show that cracks will not grow into unstable fractures under maximum design load conditions, even when such a circumferential crack is assumed to be 6 times the size of the wall thickness.

Tanaka, T.; Kameyama, M. [Kansai Electric Power Company, Osaka (Japan); Urabe, Y. [Mitsubishi Heavy Industries, Ltd., Takasago (Japan)] [and others

1997-04-01T23:59:59.000Z

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

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

122

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

123

Catalytic study of SOFC electrode materials in engine exhaust gas Pauline Briaulta  

E-Print Network [OSTI]

1 Catalytic study of SOFC electrode materials in engine exhaust gas atmosphere Pauline Briaulta. An innovative application of this system would be to recover energy from exhaust gas of a thermal engine in a mixture of hydrocarbons (propane, propene), oxygen, carbon monoxide, carbon dioxide, hydrogen and water

Paris-Sud XI, Université de

124

Development of crack shape: LBB methodology for cracked pipes  

SciTech Connect (OSTI)

For structures like vessels or pipes containing a fluid, the Leak-Before-Break (LBB) assessment requires to demonstrate that it is possible, during the lifetime of the component, to detect a rate of leakage due to a possible defect, the growth of which would result in a leak before-break of the component. This LBB assessment could be an important contribution to the overall structural integrity argument for many components. The aim of this paper is to review some practices used for LBB assessment and to describe how some new R & D results have been used to provide a simplified approach of fracture mechanics analysis and especially the evaluation of crack shape and size during the lifetime of the component.

Moulin, D.; Chapuliot, S.; Drubay, B. [Commissariat a l Energie Atomique, Gif sur Yvette (France)

1997-04-01T23:59:59.000Z

125

Crack shape developments and leak rates for circumferential complex-cracked pipes  

SciTech Connect (OSTI)

A computerized procedure has been developed that predicts the growth of an initial circumferential surface crack through a pipe and further on to failure. The crack growth mechanism can either be fatigue or stress corrosion. Consideration is taken to complex crack shapes and for the through-wall cracks, crack opening areas and leak rates are also calculated. The procedure is based on a large number of three-dimensional finite element calculations of cracked pipes. The results from these calculations are stored in a database from which the PC-program, denoted LBBPIPE, reads all necessary information. In this paper, a sensitivity analysis is presented for cracked pipes subjected to both stress corrosion and vibration fatigue.

Brickstad, B.; Bergman, M. [SAQ Inspection Ltd., Stockholm (Sweden)

1997-04-01T23:59:59.000Z

126

Plasma-assisted catalytic storage reduction system  

DOE Patents [OSTI]

A two-stage method for NO.sub.x reduction in an oxygen-rich engine exhaust comprises a plasma oxidative stage and a storage reduction stage. The first stage employs a non-thermal plasma treatment of NO.sub.x gases in an oxygen-rich exhaust and is intended to convert NO to NO.sub.2 in the presence of O.sub.2 and hydrocarbons. The second stage employs a lean NO.sub.x trap to convert such NO.sub.2 to environmentally benign gases that include N.sub.2, CO.sub.2, and H.sub.2 O. By preconverting NO to NO.sub.2 in the first stage with a plasma, the efficiency of the second stage for NO.sub.x reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber in which a non-thermal plasma converts NO to NO.sub.2 in the presence of O.sub.2 and hydrocarbons, such as propene. A flow of such hydrocarbons (C.sub.x H.sub.y) is input from usually a second pipe into at least a portion of the first chamber. The NO.sub.2 from the plasma treatment proceeds to a storage reduction catalyst (lean NO.sub.x trap) that converts NO.sub.2 to N.sub.2, CO.sub.2, and H.sub.2 O, and includes a nitrate-forming catalytic site. The hydrocarbons and NO.sub.x are simultaneously reduced while passing through the lean-NO.sub.x trap catalyst. The method allows for enhanced NO.sub.x reduction in vehicular engine exhausts, particularly those having relatively high sulfur contents.

Penetrante, Bernardino M. (San Ramon, CA); Vogtlin, George E. (Fremont, CA); Merritt, Bernard T. (Livermore, CA); Brusasco, Raymond M. (Livermore, CA)

2002-01-01T23:59:59.000Z

127

Plasma-assisted catalytic storage reduction system  

DOE Patents [OSTI]

A two-stage method for NO.sub.x reduction in an oxygen-rich engine exhaust comprises a plasma oxidative stage and a storage reduction stage. The first stage employs a non-thermal plasma treatment of NO.sub.x gases in an oxygen-rich exhaust and is intended to convert NO to NO.sub.2 in the presence of O.sub.2 and hydrocarbons. The second stage employs a lean NO.sub.x trap to convert such NO.sub.2 to environmentally benign gases that include N.sub.2, CO.sub.2, and H.sub.2 O. By preconverting NO to NO.sub.2 in the first stage with a plasma, the efficiency of the second stage for NO.sub.x reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber in which a non-thermal plasma converts NO to NO.sub.2 in the presence of O.sub.2 and hydrocarbons, such as propene. A flow of such hydrocarbons (C.sub.x H.sub.y) is input from usually a second pipe into at least a portion of the first chamber. The NO.sub.2 from the plasma treatment proceeds to a storage reduction catalyst (lean NO.sub.x trap) that converts NO.sub.2 to N.sub.2, CO.sub.2, and H.sub.2 O, and includes a nitrate-forming catalytic site. The hydrocarbons and NO.sub.x are simultaneously reduced while passing through the lean-NO.sub.x trap catalyst. The method allows for enhanced NO.sub.x reduction in vehicular engine exhausts, particularly those having relatively high sulfur contents.

Penetrante, Bernardino M. (San Ramon, CA); Vogtlin, George E. (Fremont, CA); Merritt, Bernard T. (Livermore, CA); Brusasco, Raymond M. (Livermore, CA)

2000-01-01T23:59:59.000Z

128

SciTech Connect: CRACK TIP PLASTICITY AND FRACTURE INITIATION...  

Office of Scientific and Technical Information (OSTI)

N50000* --Metals, Ceramics, & Other Materials; CRACKS; FRACTURE PROPERTIES; METALS BUILDING MATERIALSfracture of metal, crack tip plasticity and initiation criteria for;...

129

Life prediction for bridged fatigue cracks  

SciTech Connect (OSTI)

One of the more promising classes of composites touted for high temperature applications, and certainly the most available, is that of relatively brittle matrices, either ceramic or intermetallic, reinforced by strong, aligned, continuous fibers. Under cyclic loading in the fiber direction, these materials develop matrix cracks that often run perpendicular to the fibers, while the fibers remain intact in the crack wake, supplying bridging tractions across the fracture surfaces. The bridging tractions shield the crack tip from the applied load, dramatically reducing the crack velocity from that expected in an unreinforced material subjected to the same value, {Delta}K{sub a}, of the cyclic applied stress intensity factor. An important issue in reliability is the prediction of the growth rates of the bridged cracks. The growth rates of matrix fatigue cracks bridged by sliding fibers are now commonly predicted by models based on the micromechanics of frictional interfaces. However, there exist many reasons, both theoretical and experimental, for suspecting that the most popular micromechanical models are probably wrong in detail in the context of fatigue cracks. Furthermore, a review of crack growth data reveals that the validity of the micromechanics-based predictive model has never been tested and may never be tested. In this paper, two alternative approaches are suggested to the engineering problem of predicting the growth rates of bridged cracks without explicit recourse to micromechanics. Instead, it is shown that the material properties required to analyze bridging effects can be deduced directly from crack growth data. Some experiments are proposed to test the validity of the proposals.

Cox, B.N.

1994-08-01T23:59:59.000Z

130

Superconducting Cuprates on Catalytic Substrates - Energy Innovation...  

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

Transmission Electricity Transmission Find More Like This Return to Search Superconducting Cuprates on Catalytic Substrates Brookhaven National Laboratory Contact BNL About...

131

Bifunctional Catalysts for the Selective Catalytic Reduction...  

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

3 DEER Conference Presentation: Argonne National Laboratory 2003deermarshall.pdf More Documents & Publications Selectlive Catalytic Reducution of NOx wilth Diesel-Based Fuels as...

132

Catalytic membranes for fuel cells  

DOE Patents [OSTI]

A fuel cell of the present invention comprises a cathode and an anode, one or both of the anode and the cathode including a catalyst comprising a bundle of longitudinally aligned graphitic carbon nanotubes including a catalytically active transition metal incorporated longitudinally and atomically distributed throughout the graphitic carbon walls of said nanotubes. The nanotubes also include nitrogen atoms and/or ions chemically bonded to the graphitic carbon and to the transition metal. Preferably, the transition metal comprises at least one metal selected from the group consisting of Fe, Co, Ni, Mn, and Cr.

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

2011-04-19T23:59:59.000Z

133

Nanorods, nanospheres, nanocubes: Synthesis, characterization and catalytic activity of nanoferrites of Mn, Co, Ni, Part-89  

SciTech Connect (OSTI)

Graphical abstract: Prepared nanoferrites were characterized by FE-SEM and bright field TEM micrographs. The catalytic effect of these nanoferrites was evaluated on the thermal decomposition of ammonium perchlorate using TG and TG–DSC techniques. The kinetics of thermal decomposition of AP was evaluated using isothermal TG data by model fitting as well as isoconversional method. Display Omitted Highlights: ? Synthesis of ferrite nanostructures (?20.0 nm) by wet-chemical method under different synthetic conditions. ? Characterization using XRD, FE-SEM, EDS, TEM, HRTEM and SAED pattern. ? Catalytic activity of ferrite nanostructures on AP thermal decomposition by thermal techniques. ? Burning rate measurements of CSPs with ferrite nanostructures. ? Kinetics of thermal decomposition of AP + nanoferrites. -- Abstract: In this paper, the nanoferrites of Mn, Co and Ni were synthesized by wet chemical method and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive, X-ray spectra (EDS), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HR-TEM). It is catalytic activity were investigated on the thermal decomposition of ammonium perchlorate (AP) and composite solid propellants (CSPs) using thermogravimetry (TG), TG coupled with differential scanning calorimetry (TG–DSC) and ignition delay measurements. Kinetics of thermal decomposition of AP + nanoferrites have also been investigated using isoconversional and model fitting approaches which have been applied to data for isothermal TG decomposition. The burning rate of CSPs was considerably enhanced by these nanoferrites. Addition of nanoferrites to AP led to shifting of the high temperature decomposition peak toward lower temperature. All these studies reveal that ferrite nanorods show the best catalytic activity superior to that of nanospheres and nanocubes.

Singh, Supriya; Srivastava, Pratibha [Department of Chemistry, D.D.U. Gorakhpur University, Gorakhpur 273009 (India)] [Department of Chemistry, D.D.U. Gorakhpur University, Gorakhpur 273009 (India); Singh, Gurdip, E-mail: gsingh4us@yahoo.com [Department of Chemistry, D.D.U. Gorakhpur University, Gorakhpur 273009 (India)] [Department of Chemistry, D.D.U. Gorakhpur University, Gorakhpur 273009 (India)

2013-02-15T23:59:59.000Z

134

Catalytic Combustion for Ultra-Low NOx Hydrogen Turbines  

SciTech Connect (OSTI)

Precision Combustion, Inc., (PCI) in close collaboration with Solar Turbines, Incorporated, has developed and demonstrated a combustion system for hydrogen fueled turbines that reduces NOx to low single digit level while maintaining or improving current levels of efficiency and eliminating emissions of carbon dioxide. Full scale Rich Catalytic Hydrogen (RCH1) injector was developed and successfully tested at Solar Turbines, Incorporated high pressure test facility demonstrating low single digit NOx emissions for hydrogen fuel in the range of 2200F-2750F. This development work was based on initial subscale development for faster turnaround and reduced cost. Subscale testing provided promising results for 42% and 52% H2 with NOx emissions of less than 2 ppm with improved flame stability. In addition, catalytic reactor element testing for substrate oxidation, thermal cyclic injector testing to simulate start-stop operation in a gas turbine environment, and steady state 15 atm. operation testing were performed successfully. The testing demonstrated stable and robust catalytic element component life for gas turbine conditions. The benefit of the catalytic hydrogen combustor technology includes capability of delivering near-zero NOx without costly post-combustion controls and without requirement for added sulfur control. In addition, reduced acoustics increase gas turbine component life. These advantages advances Department of Energy (DOE’s) objectives for achievement of low single digit NOx emissions, improvement in efficiency vs. postcombustion controls, fuel flexibility, a significant net reduction in Integrated Gasification Combined Cycle (IGCC) system net capital and operating costs, and a route to commercialization across the power generation field from micro turbines to industrial and utility turbines.

Etemad, Shahrokh; Baird, Benjamin; Alavandi, Sandeep

2011-06-30T23:59:59.000Z

135

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

136

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. 7 figs.

Benson, D.K.; Potter, T.F.

1995-12-26T23:59:59.000Z

137

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

138

The Effects of Test Temperature, Temper, and Alloyed Copper on the Hydrogen-Controlled Crack Growth Rate of an Al-Zn-Mg-(Cu) Alloy  

SciTech Connect (OSTI)

The hydrogen embrittlement controlled stage II crack growth rate of AA 7050 (6.09 wt.% Zn, 2.14 wt% Mg, 2.19 wt.% Cu) was investigated as a function of temper and alloyed copper level in a humid air environment at various temperatures. Three tempers representing the underaged, peak aged, and overaged conditions were tested in 90% relative humidity (RH) air at temperatures between 25 and 90 C. At all test temperatures, an increased degree of aging (from underaged to overaged) produced slower stage II crack growth rates. The stage II crack growth rate of each alloy and temper displayed Arrhenius-type temperature dependence with activation energies between 58 and 99 kJ/mol. For both the normal copper and low copper alloys, the fracture path was predominantly intergranular at all test temperatures (25-90 C) in each temper investigated. Comparison of the stage II crack growth rates for normal (2.19 wt.%) and low (0.06 wt.%) copper alloys in the peak aged and overaged tempers showed the beneficial effect of copper additions on stage II crack growth rate in humid air. In the 2.19 wt.% copper alloy, the significant decrease ({approx} 10 times at 25 C) in stage II crack growth rate upon overaging is attributed to an increase in the apparent activation energy for crack growth. IN the 0.06 wt.% copper alloy, overaging did not increase the activation energy for crack growth but did lower the pre-exponential factor, {nu}{sub 0}, resulting in a modest ({approx} 2.5 times at 25 C) decrease in crack growth rate. These results indicate that alloyed copper and thermal aging affect the kinetic factors that govern stage II crack growth rate. Overaged, copper bearing alloys are not intrinsically immune to hydrogen environment assisted cracking but are more resistant due to an increased apparent activation energy for stage II crack growth.

G.A. Young, Jr.; J.R. Scully

2000-09-17T23:59:59.000Z

139

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...

140

Nanoporous carbon catalytic membranes and method for making the same  

DOE Patents [OSTI]

Catalytic membranes comprising highly-dispersed, catalytically-active metals in nanoporous carbon membranes and a novel single-phase process to produce the membranes.

Foley, Henry C. (Hockessin, DE); Strano, Michael (Wilmington, DE); Acharya, Madhav (New Castle, DE); Raich, Brenda A. (Houston, TX)

2002-01-01T23:59:59.000Z

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.


141

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...

142

High Catalytic Rates for Hydrogen Production Using Nickel Electrocatal...  

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

High Catalytic Rates for Hydrogen Production Using Nickel Electrocatalysts with Seven-Membered Diphosphine Ligands Containing High Catalytic Rates for Hydrogen Production Using...

143

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...

144

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

145

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

146

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

147

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

148

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

149

An investigation of penetrant techniques for detection of machining-induced surface-breaking cracks on monolithic ceramics  

SciTech Connect (OSTI)

The purpose of this effort was to evaluate penetrant methods for their ability to detect surface-breaking cracks in monolithic ceramic materials with an emphasis on detection of cracks generated by machining. There are two basic penetrant types, visible and fluorescent. The visible penetrant method is usually augmented by powder developers and cracks detected can be seen in visible light. Cracks detected by fluorescent penetrant are visible only under ultraviolet light used with or without a developer. The developer is basically a powder that wicks up penetrant from a crack to make it more observable. Although fluorescent penetrants were recommended in the literature survey conducted early in this effort, visible penetrants and two non-standard techniques, a capillary gaseous diffusion method under development at the institute of Chemical Physics in Moscow, and the {open_quotes}statiflux{close_quotes} method which involves use of electrically charged particles, were also investigated. SiAlON ring specimens (1 in. diameter, 3/4 in. wide) which had been subjected to different thermal-shock cycles were used for these tests. The capillary gaseous diffusion method is based on ammonia; the detector is a specially impregnated paper much like litmus paper. As expected, visible dye penetrants offered no detection sensitivity for tight, surface-breaking cracks in ceramics. Although the non-standard statiflux method showed promise on high-crack-density specimens, it was ineffective on limited-crack-density specimens. The fluorescent penetrant method was superior for surface-breaking crack detection, but successful application of this procedure depends greatly on the skill of the user. Two presently available high-sensitivity fluorescent penetrants were then evaluated for detection of microcracks on Si{sub 3}N{sub 4} and SiC from different suppliers. Although 50X optical magnification may be sufficient for many applications, 200X magnification provides excellent delectability.

Forster, G.A.; Ellingson, W.A.

1996-02-01T23:59:59.000Z

150

Recent evaluations of crack-opening-area in circumferentially cracked pipes  

SciTech Connect (OSTI)

Leak-before-break (LBB) analyses for circumferentially cracked pipes are currently being conducted in the nuclear industry to justify elimination of pipe whip restraints and jet shields which are present because of the expected dynamic effects from pipe rupture. The application of the LBB methodology frequently requires calculation of leak rates. The leak rates depend on the crack-opening area of the through-wall crack in the pipe. In addition to LBB analyses which assume a hypothetical flaw size, there is also interest in the integrity of actual leaking cracks corresponding to current leakage detection requirements in NRC Regulatory Guide 1.45, or for assessing temporary repair of Class 2 and 3 pipes that have leaks as are being evaluated in ASME Section XI. The objectives of this study were to review, evaluate, and refine current predictive models for performing crack-opening-area analyses of circumferentially cracked pipes. The results from twenty-five full-scale pipe fracture experiments, conducted in the Degraded Piping Program, the International Piping Integrity Research Group Program, and the Short Cracks in Piping and Piping Welds Program, were used to verify the analytical models. Standard statistical analyses were performed to assess used to verify the analytical models. Standard statistical analyses were performed to assess quantitatively the accuracy of the predictive models. The evaluation also involved finite element analyses for determining the crack-opening profile often needed to perform leak-rate calculations.

Rahman, S.; Brust, F.; Ghadiali, N.; Wilkowski, G.; Miura, N.

1997-04-01T23:59:59.000Z

151

TRANSPORT THROUGH CRACKED CONCRETE: LITERATURE REVIEW  

SciTech Connect (OSTI)

Concrete containment structures and cement-based fills and waste forms are used at the Savannah River Site to enhance the performance of shallow land disposal systems designed for containment of low-level radioactive waste. Understanding and measuring transport through cracked concrete is important for describing the initial condition of radioactive waste containment structures at the Savannah River Site (SRS) and for predicting performance of these structures over time. This report transmits the results of a literature review on transport through cracked concrete which was performed by Professor Jason Weiss, Purdue University per SRR0000678 (RFP-RQ00001029-WY). This review complements the NRC-sponsored literature review and assessment of factors relevant to performance of grouted systems for radioactive waste disposal. This review was performed by The Center for Nuclear Waste Regulatory Analyses, San Antonio, TX, and The University of Aberdeen, Aberdeen Scotland and was focused on tank closure. The objective of the literature review on transport through cracked concrete was to identify information in the open literature which can be applied to SRS transport models for cementitious containment structures, fills, and waste forms. In addition, the literature review was intended to: (1) Provide a framework for describing and classifying cracks in containment structures and cementitious materials used in radioactive waste disposal, (2) Document the state of knowledge and research related to transport through cracks in concrete for various exposure conditions, (3) Provide information or methodology for answering several specific questions related to cracking and transport in concrete, and (4) Provide information that can be used to design experiments on transport through cracked samples and actual structures.

Langton, C.

2012-05-11T23:59:59.000Z

152

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

153

Thermal Fluids  

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

Thermal Fluids The Thermal Fluids and Heat Transfer program works on thermal hydraulic reactor safety code development and experimental heat transferthermal hydraulics. The...

154

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....

155

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......

156

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

157

Linking Grain Boundary Microstructure to Stress Corrosion Cracking of Cold Rolled Alloy 690 in PWR Primary Water  

SciTech Connect (OSTI)

Grain boundary microstructures and microchemistries are examined in cold-rolled alloy 690 tubing and plate materials and comparisons are made to intergranular stress corrosion cracking (IGSCC) behavior in PWR primary water. Chromium carbide precipitation is found to be a key aspect for materials in both the mill annealed and thermally treated conditions. Cold rolling to high levels of reduction was discovered to produce small IG voids and cracked carbides in alloys with a high density of grain boundary carbides. The degree of permanent grain boundary damage from cold rolling was found to depend directly on the initial IG carbide distribution. For the same degree of cold rolling, alloys with few IG precipitates exhibited much less permanent damage. Although this difference in grain boundary damage appears to correlate with measured SCC growth rates, crack tip examinations reveal that cracked carbides appeared to blunt propagation of IGSCC cracks in many cases. Preliminary results suggest that the localized grain boundary strains and stresses produced during cold rolling promote IGSCC susceptibility and not the cracked carbides and voids.

Bruemmer, Stephen M.; Olszta, Matthew J.; Toloczko, Mychailo B.; Thomas, Larry E.

2012-10-01T23:59:59.000Z

158

Environmentally assisted cracking of LWR materials.  

SciTech Connect (OSTI)

The effect of dissolved oxygen level on fatigue life of austenitic stainless steels is discussed and the results of a detailed study of the effect of the environment on the growth of cracks during fatigue initiation are presented. Initial test results are given for specimens irradiated in the Halden reactor. Impurities introduced by shielded metal arc welding that may affect susceptibility to stress corrosion cracking are described. Results of calculations of residual stresses in core shroud weldments are summarized. Crack growth rates of high-nickel alloys under cyclic loading with R ratios from 0.2-0.95 in water that contains a wide range of dissolved oxygen and hydrogen concentrations at 289 and 320 C are summarized.

Chopra, O. K.; Chung, H. M.; Kassner, T. F.; Park, J. H.; Shack, W. J.; Zhang, J.; Brust, F. W.; Dong, P.

1997-12-05T23:59:59.000Z

159

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

160

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.

Migliori, Albert (Santa Fe, NM); Bell, Thomas M. (Santa Fe, NM); Rhodes, George W. (Albuquerque, NM)

1994-01-01T23:59:59.000Z

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.


161

Fast electromigration crack in nanoscale aluminum film  

SciTech Connect (OSTI)

The current-induced breakage of 20?nm thin aluminum layers deposited onto capacitor grade polypropylene (PP) films is experimentally studied. Biexponential current pulses of different amplitude (10–15?A) and duration (0.1–1??s) were applied to the samples. Breakage occurred after fast development of electromigrating ?200?nm-wide cracks with initial propagation velocity of ?1?m/s under a high current density of ?10{sup 12?}A/m{sup 2}. The cracks stopped when their lengths reached 250–450??m. This behavior is explained by the balance of electromigration and stress-induced atomic fluxes.

Emelyanov, O. A., E-mail: oaemel2@gmail.com; Ivanov, I. O. [St. Petersburg State Polytechnical University, Saint-Petersburg (Russian Federation)

2014-08-14T23:59:59.000Z

162

Interim Report on Thermal Cycling Model Development for Representative Unisolable Piping Configurations (MRP-81)  

SciTech Connect (OSTI)

Thermal fatigue can lead to cracking in dead-ended branch lines attached to PWR primary coolant piping. This interim report describes the results of on-going research to provide an improved screening tool for identification of susceptible piping.

J. Keller, A. Bilanin

2002-11-30T23:59:59.000Z

163

Crack closure effects on fatigue crack growth thresholds and remaining life in an HSLA steel  

SciTech Connect (OSTI)

The effects of crack closure on the near-threshold corrosion fatigue crack growth behavior of Mil S-24645 HSLA steel and its weld metal have been investigated in air, ASTM seawater at the free corrosion potential, and ASTM seawater at {minus}0.8V and {minus}1.0V (SCE) using frequencies of 10, 2, and 0.2 Hz, and a stress ratio, R = 0.1. Remaining life, in the presence and absence of crack closure, has been estimated as a function of applied stress range for a structure containing a 3-mm-deep surface semi-elliptical flaw.

Todd, J.A.; Mostovoy, S. [Illinois Inst. of Tech., Chicago, IL (United States). Dept. of Mechanical, Materials and Aerospace Engineering; Chen, L. [Texas Instruments, Attleboro, MA (United States); Yankov, E.Y. [A. Finkl and Sons, Chicago, IL (United States)

1997-02-01T23:59:59.000Z

164

Fabrication of fuel cell electrodes and other catalytic structures  

DOE Patents [OSTI]

A porous layer of catalyst material suitable for use as an electrode in a molten carbonate fuel cell includes elongated pores substantially extending across the layer thickness. The catalyst layer is prepared by depositing particulate catalyst material into polymeric flocking on a substrate surface by a procedure such as tape casting. The loaded substrate is heated in a series of steps with rising temperatures to set the tape, thermally decompose the substrate with flocking and sinter bond the catalyst particles into a porous catalytic layer with elongated pores across its thickness. Employed as an electrode, the elongated pores provide distribution of reactant gas into contact with catalyst particles wetted by molten electrolyte. 1 fig.

Smith, J.L.

1987-02-11T23:59:59.000Z

165

Environmentally assisted cracking in Light Water Reactors: Semiannual report, April 1993--September 1993. Volume 17  

SciTech Connect (OSTI)

This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRS) during the six months from April 1993 to September 1993. EAC and fatigue of piping, pressure vessels, and core components in LWRs are important concerns as extended reactor lifetimes are envisaged. Topics that have been investigated include (a) fatigue of low-alloy steel used in piping, steam generators, and reactor pressure vessels; (b) EAC of cast stainless steels (SSs); and (c) radiation-induced segregation and irradiation-assisted stress corrosion cracking of Type 304 SS after accumulation of relatively high fluence. Fatigue tests were conducted on medium-sulfur-content A106-Gr B piping and A533-Gr B pressure vessel steels in simulated PWR water and in air. Additional crack growth data were obtained on fracture-mechanics specimens of cast austenitic SSs in the as-received and thermally aged conditions in simulated boiling-water reactor (BWR) water at 289{degree}C. The data were compared with predictions based on crack growth correlations for wrought austenitic SS in oxygenated water developed at ANL and rates in air from Section 11 of the ASME Code. Microchemical and microstructural changes in high- and commercial-purity Type 304 SS specimens from control-blade absorber tubes and a control-blade sheath from operating BWRs were studied by Auger electron spectroscopy and scanning electron microscopy.

Chopra, O.K.; Chung, H.M.; Karlsen, T.; Kassner, T.F.; Michaud, W.F.; Ruther, W.E.; Sanecki, J.E.; Shack, W.J.; Soppet, W.K. [Argonne National Lab., IL (United States)

1994-06-01T23:59:59.000Z

166

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

167

Grain Boundary Structure Effects on Intergranular Stress Corrosion Cracking of  

E-Print Network [OSTI]

Grain Boundary Structure Effects on Intergranular Stress Corrosion Cracking of Alloy X­750 Y. Pan B­of­freedom) and correlations with intergranular stress corrosion cracking observed in Alloy X­750. Orientation imaging

Olson, Tamara

168

Reflective Cracking Study: HVS Test Section Forensic Investigation  

E-Print Network [OSTI]

the asphalt concrete. Summary of Testing on the Underlyingtesting performed to validate Caltrans overlay strategies for the rehabilitation of cracked asphalt concrete.concrete. It describes the forensic investigation of the HVS rutting and reflective cracking testing

Jones, David; Steven, B.; Harvey, John T

2008-01-01T23:59:59.000Z

169

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

170

Environmentally assisted cracking in light water reactors  

SciTech Connect (OSTI)

This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) from April 1995 to December 1995. Topics that have been investigated include fatigue of carbon and low-alloy steel used in reactor piping and pressure vessels, EAC of Alloy 600 and 690, and irradiation-assisted stress corrosion cracking (IASCC) of Type 304 SS. Fatigue tests were conducted on ferritic steels in water that contained various concentrations of dissolved oxygen (DO) to determine whether a slow strain rate applied during different portions of a tensile-loading cycle are equally effective in decreasing fatigue life. Crack-growth-rate tests were conducted on compact-tension specimens from several heats of Alloys 600 and 690 in simulated LWR environments. Effects of fluoride-ion contamination on susceptibility to intergranular cracking of high- and commercial- purity Type 304 SS specimens from control-tensile tests at 288 degrees Centigrade. Microchemical changes in the specimens were studied by Auger electron spectroscopy and scanning electron microscopy to determine whether trace impurity elements may contribute to IASCC of these materials.

Chopra, O.K.; Chung, H.M.; Gruber, E.E. [and others

1996-07-01T23:59:59.000Z

171

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

172

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

173

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

174

Stress corrosion cracking and crack tip characterization of Alloy X-750 in light water reactor environments  

E-Print Network [OSTI]

Stress corrosion cracking (SCC) susceptibility of Inconel Alloy X-750 in the HTH condition has been evaluated in high purity water at 93 and 288°C under Boiling Water Reactor Normal Water Chemistry (NWC) and Hydrogen Water ...

Gibbs, Jonathan Paul

2011-01-01T23:59:59.000Z

175

Stress Corrosion Cracking and Crack Tip Characterization of Alloy X-750 in Light Water Reactor Environments  

E-Print Network [OSTI]

Stress corrosion cracking (SCC) susceptibility of Inconel Alloy X-750 in the HTH condition has been evaluated in high purity water at 93 and 288°C under Boiling Water Reactor Normal Water Chemistry (NWC) and Hydrogen Water ...

Gibbs, Jonathan Paul

176

Enhanced ultrasonic detection of fatigue cracks by laser-induced crack closure  

E-Print Network [OSTI]

, corrosion, etc. . Sec- ond, it is important to distinguish small fatigue cracks as early as possible after threshold in aluminum, aluminum­ lithium, and titanium alloys.1 For example, extensive multiple-site fatigue

Nagy, Peter B.

177

CRACK STATISTIC OF CRYSTALLINE SILICON PHOTOVOLTAIC MODULES M. Kntges1  

E-Print Network [OSTI]

the risk of cracks, as well as for statistical power loss assessment. Keywords: PV module, micro cracks separation, thus resulting in inactive cell parts. For this special case a clear assessment of the power loss this gap and provide a first statistic of cracks in PV modules for future power loss assessment

178

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

E-Print Network [OSTI]

. . 7 Percentage cracks vs. time aAer placement in bike trail concrete. . . , . . . . . . 8. Development of cracking stress and strength vs. time atter placement of bike trail concrete 9. Equivalent temperature difference (between the slab top... and bottom) vs. time after placement in the bike trail concrete. . . . . . . . . . . . . , , . . . . . . . . 10, Relative humidity at 0. 75 inches below surface vs. time after placement for the bike trail concrete 11. Calculated shrinkage vs. time aAer...

Vepakomma, Shilpa

2002-01-01T23:59:59.000Z

179

Thermal Durability of Cu-CHA NH3-SCR Catalysts for Diesel NOx...  

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

Durability of Cu-CHA NH3-SCR Catalysts for Diesel NOx Reduction. Thermal Durability of Cu-CHA NH3-SCR Catalysts for Diesel NOx Reduction. Abstract: Multiple catalytic functions...

180

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

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

Electro Catalytic Oxidation (ECO) Operation  

SciTech Connect (OSTI)

The power industry in the United States is faced with meeting many new regulations to reduce a number of air pollutants including sulfur dioxide, nitrogen oxides, fine particulate matter, and mercury. With over 1,000 power plants in the US, this is a daunting task. In some cases, traditional pollution control technologies such as wet scrubbers and SCRs are not feasible. Powerspan's Electro-Catalytic Oxidation, or ECO{reg_sign} process combines four pollution control devices into a single integrated system that can be installed after a power plant's particulate control device. Besides achieving major reductions in emissions of sulfur dioxide (SO{sub 2}), nitrogen oxides (NOx), fine particulate matter (PM2.5) and mercury (Hg), ECO produces a highly marketable fertilizer, which can help offset the operating costs of the process system. Powerspan has been operating a 50-MW ECO commercial demonstration unit (CDU) at FirstEnergy Corp.'s R.E. Burger Plant near Shadyside, Ohio, since February 2004. In addition to the CDU, a test loop has been constructed beside the CDU to demonstrate higher NOx removal rates and test various scrubber packing types and wet ESP configurations. Furthermore, Powerspan has developed the ECO{reg_sign}{sub 2} technology, a regenerative process that uses a proprietary solvent to capture CO{sub 2} from flue gas. The CO{sub 2} capture takes place after the capture of NOx, SO{sub 2}, mercury, and fine particulate matter. Once the CO{sub 2} is captured, the proprietary solution is regenerated to release CO{sub 2} in a form that is ready for geological storage or beneficial use. Pilot scale testing of ECO{sub 2} began in early 2009 at FirstEnergy's Burger Plant. The ECO{sub 2} pilot unit is designed to process a 1-MW flue gas stream and produce 20 tons of CO{sub 2} per day, achieving a 90% CO{sub 2} capture rate. The ECO{sub 2} pilot program provided the opportunity to confirm process design and cost estimates, and prepare for large scale capture and sequestration projects. The objectives of this project were to prove at a commercial scale that ECO is capable of extended operations over a range of conditions, that it meets the reliability requirements of a typical utility, and that the fertilizer co-product can be consistently generated, providing ECO with an economic advantage over conventional technologies currently available. Further objectives of the project were to show that the ECO system provides flue gas that meets the inlet standards necessary for ECO{sub 2} to operate, and that the outlet CO{sub 2} and other constituents produced by the ECO{sub 2} pilot can meet Kinder-Morgan pipeline standards for purposes of sequestration. All project objectives are consistent with DOE's Pollution Control Innovations for Power Plants program goals.

Morgan Jones

2011-03-31T23:59:59.000Z

182

Why Do Kraft Recovery Boiler Composite Floor Tubes Crack?  

SciTech Connect (OSTI)

Cracks were first reported in 1992 in co-extruded 304L stainless steel/SA210 Gd Al carbon steel floor tubes of North American black liquor recovery boilers. Since then, a considerable amount of information has been collected on the tube environment, crack characteristics, the stress state of the tubes, and the crack initiation and propagation mechanisms. These studies have identified both operating procedures that apparently can greatly lessen the likelihood of crack formation in the stainless steel layer and alternate materials that appear to be much more resistant to cracking than is 304L stainless.

Keiser, J.R.

2001-10-22T23:59:59.000Z

183

Stress corrosion cracking behavior of Alloy 600 in high temperature water  

SciTech Connect (OSTI)

SCC susceptibility of Alloy 600 in deaerated water at 360 C (statically loaded U-bend specimens) is dependent on microstructure and whether the material was cold-worked and annealed (CWA) or hot-worked and annealed (HWA). All cracking was intergranular, and materials lacking grain boundary carbides were most susceptible to SCC initiation. CWA tubing materials are more susceptible to SCC initiation than HWA ring-rolled forging materials with similar microstructures (optical metallography). In CWA tubing materials, one crack dominated and grew to a visible size. HWA materials with a low hot-working finishing temperature (<925 C) and final anneals at 1010-1065 C developed both large cracks (similar to those in CWA materials) and small intergranular microcracks detectable only by destructive metallography. HWA materials with a high hot-working finishing temperature (>980 C) and a high-temperature final anneal (>1040 C), with grain boundaries that are fully decorated, developed only microcracks in all specimens. These materials did not develop large, visually detectable cracks, even after more than 300 weeks exposure. A low-temperature thermal treatment (610 C for 7h), which reduces or eliminates SCC in Alloy 600, did not eliminate microcrack formation in high temperature processed HWA materials. Conventional metallographic and analytical electron microscopy (AEM) were done on selected materials to identify the factors responsible for the observed differences in cracking behavior. Major difference between high-temperature HWA and low-temperature HWA and CWA materials was that the high temperature processing and final annealing produced predominantly ``semi-continuous`` dendritic M{sub 7}C{sub 3} carbides along grain boundaries with a minimal amount of intragranular carbides. Lower temperature processing produced intragranular M7C3 carbides, with less intergranular carbides.

Webb, G.L.; Burke, M.G.

1995-07-01T23:59:59.000Z

184

Heavy-Section Steel Technology Program: Recent developments in crack initiation and arrest research  

SciTech Connect (OSTI)

Technology for the analysis of crack initiation and arrest is central to the reactor pressure vessel fracture-margin-assessment process. Regulatory procedures for nuclear plants utilize this technology to assure the retention of adequate fracture-prevention margins throughout the plant operating license period. As nuclear plants age and regulatory procedures dictate that fracture-margin assessments be performed, interest in the fracture-mechanics technology incorporated into those procedures has heightened. This has led to proposals from a number of sources for development and refinement of the underlying crack-initiation and arrest-analysis technology. This paper presents an overview of ongoing Heavy-Section Steel Technology (HSST) Program research aimed at refining the fracture toughness data used in the analysis of fracture margins under pressurized-thermal-shock loading conditions. 33 refs., 13 figs.

Pennell, W.E.

1991-01-01T23:59:59.000Z

185

Soil cracking modelling using the mesh-free SPH method  

E-Print Network [OSTI]

The presence of desiccation cracks in soils can significantly alter their mechanical and hydrological properties. In many circumstances, desiccation cracking in soils can cause significant damage to earthen or soil supported structures. For example, desiccation cracks can act as the preference path way for water flow, which can facilitate seepage flow causing internal erosion inside earth structures. Desiccation cracks can also trigger slope failures and landslides. Therefore, developing a computational procedure to predict desiccation cracking behaviour in soils is vital for dealing with key issues relevant to a range of applications in geotechnical and geo-environment engineering. In this paper, the smoothed particle hydrodynamics (SPH) method will be extended for the first time to simulate shrinkage-induced soil cracking. The main objective of this work is to examine the performance of the proposed numerical approach in simulating the strong discontinuity in material behaviour and to learn about the crack ...

Bui, H H; Kodikara, J; Sanchez, M

2015-01-01T23:59:59.000Z

186

Modeling and Optimization of Direct Chill Casting to Reduce Ingot Cracking  

SciTech Connect (OSTI)

A successful four-year project on the modeling and optimization of direct chill (DC) casting to reduce ingot cracking has been completed. The project involved close collaboration among private industries, national laboratories, and universities. During the four-year project, 16 quarterly meetings brought the industrial partners and the research team together for discussion of 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. The collaborative research resulted in several major accomplishments or findings: (1) Surface cracks were shown to be a result of hot tearing rather than cold cracks, as was thought before this project. These cracks form on the surface of a DC cast ingot just above the impingement point of the secondary cooling water jets. The cracks form along dendrite and grain boundaries, where solute and impurity elements are highly segregated. This understanding led to the development of a new technique for determining the mechanical properties in the nonequilibrium mushy zone of alloys and to thermodynamic predictions of the hot tearing propensity of DC cast ingots. (2) The apparent heat transfer coefficient (HTC) at the ingot surface in the water cooling region during DC casting was determined on the basis of temperature measurements in commercial DC casting ingots and an inverse heat transfer analysis. HTCs were calculated as a function of temperature and time, and covered the different regimes of heat transfer expected during DC casting. The calculated values were extrapolated to include the effect of water flow rate. The calculated HTCs had a peak at around 200 C, corresponding to the high heat transfer rates during nucleate boiling, and the profile was consistent with similar data published in the literature. (3) A new method, termed the reheating-cooling method (RCM), was developed and validated for measuring mechanical properties in the nonequilibrium mushy zones of alloys. The new method captures the brittle nature of aluminum alloys at temperatures close to the nonequilibrium solidus temperature, while specimens tested using the reheating method exhibit significant ductility. The RCM has been used for determining the mechanical properties of alloys at nonequilibrium mushy zone temperatures. Accurate data obtained during this project show that the metal becomes more brittle at high temperatures and high strain rates. (4) The elevated-temperature mechanical properties of the alloy were determined. Constitutive models relating the stress and strain relationship at elevated temperatures were also developed. The experimental data fit the model well. (5) An integrated 3D DC casting model has been used to simulate heat transfer, fluid flow, solidification, and thermally induced stress-strain during casting. A temperature-dependent HTC between the cooling water and the ingot surface, cooling water flow rate, and air gap were coupled in this model. An elasto-viscoplastic model based on high-temperature mechanical testing was used to calculate the stress during casting. The 3D integrated model can be used for the prediction of temperature, fluid flow, stress, and strain distribution in DC cast ingots. (6) The cracking propensity of DC cast ingots can be predicted using the 3D integrated model as well as thermodynamic models. Thus, an ingot cracking index based on the ratio of local stress to local alloy strength was established. Simulation results indicate that cracking propensity increases with increasing casting speed. The composition of the ingots also has a major effect on cracking formation. It was found that copper and zinc increase the cracking propensity of DC cast ingots. The goal of this Aluminum Industry of the Future (IOF) project was to assist the aluminum industry in reducing the incidence of stress cracks in DC castings from a current level of 5% down to 2%. This could lead to energy savings

Das, Subodh K.

2006-01-09T23:59:59.000Z

187

Porous Core-Shell Nanostructures for Catalytic Applications  

E-Print Network [OSTI]

C.Y Mou. Catalytic nano-rattle of Au@ hollow silica: towardshollow nanostructures induced by the Kirkendall effect: The basic concept. NanoHollow mesoporous aluminosilica spheres with perpendicular pore channels as catalytic nanoreactors. ACS Nano,

Ewers, Trevor David

2012-01-01T23:59:59.000Z

188

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

189

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

190

Transparent and Catalytic Carbon Nanotube Films  

E-Print Network [OSTI]

, a reaction that is important for the dye-sensitized solar cell, with a charge-transfer resistance as measured for the dye-sensitized solar cell. Other possible applications include batteries, fuel cells to be electrochemically active in several systems.1,8­15 For example, they are catalytic in the dye-sensitized solar cell

Hone, James

191

Performance characterization of a hydrogen catalytic heater.  

SciTech Connect (OSTI)

This report describes the performance of a high efficiency, compact heater that uses the catalytic oxidation of hydrogen to provide heat to the GM Hydrogen Storage Demonstration System. The heater was designed to transfer up to 30 kW of heat from the catalytic reaction to a circulating heat transfer fluid. The fluid then transfers the heat to one or more of the four hydrogen storage modules that make up the Demonstration System to drive off the chemically bound hydrogen. The heater consists of three main parts: (1) the reactor, (2) the gas heat recuperator, and (3) oil and gas flow distribution manifolds. The reactor and recuperator are integrated, compact, finned-plate heat exchangers to maximize heat transfer efficiency and minimize mass and volume. Detailed, three-dimensional, multi-physics computational models were used to design and optimize the system. At full power the heater was able to catalytically combust a 10% hydrogen/air mixture flowing at over 80 cubic feet per minute and transfer 30 kW of heat to a 30 gallon per minute flow of oil over a temperature range from 100 C to 220 C. The total efficiency of the catalytic heater, defined as the heat transferred to the oil divided by the inlet hydrogen chemical energy, was characterized and methods for improvement were investigated.

Johnson, Terry Alan; Kanouff, Michael P.

2010-04-01T23:59:59.000Z

192

SCREENING TESTS FOR IMPROVED METHANE CRACKING MATERIALS  

SciTech Connect (OSTI)

Bench scale (1 to 6 gram) methane cracking tests have been performed on a variety of pure elements, some alloys, and SAES{reg_sign} commercial getters St 101, St 198, St 707, St 737, and St 909 to determine methane cracking performance (MCP) of 5% methane in a helium carrier at 700 C, 101.3 kPa (760 torr) with a 10 sccm feed. The MCP was almost absent from some materials tested while others showed varying degrees of MCP. Re, Cr, V, Gd, and Mo powders had good MCP, but limited capacities. Nickel supported on kieselguhr (Ni/k), a Zr-Ni alloy, and the SAES{reg_sign} getters had good MCP in a helium carrier. The MCP of these same materials was suppressed in a hydrogen carrier stream and the MCP of the Zr-based materials was reduced by nitride formation when tested with a nitrogen carrier gas.

Klein, J; Jeffrey Holder, J

2007-07-16T23:59:59.000Z

193

Circumferential cracking of steam generator tubes  

SciTech Connect (OSTI)

On April 28, 1995, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 95-03, {open_quote}Circumferential Cracking of Steam Generator Tubes.{close_quote} GL 95-03 was issued to obtain information needed to verify licensee compliance with existing regulatory requirements regarding the integrity of steam generator tubes in domestic pressurized-water reactors (PWRs). This report briefly describes the design and function of domestic steam generators and summarizes the staff`s assessment of the responses to GL 95-03. The report concludes with several observations related to steam generator operating experience. This report is intended to be representative of significant operating experience pertaining to circumferential cracking of steam generator tubes from April 1995 through December 1996. Operating experience prior to April 1995 is discussed throughout the report, as necessary, for completeness.

Karwoski, K.J.

1997-04-01T23:59:59.000Z

194

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

195

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

196

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

197

CDF central preshower and crack detector upgrade  

SciTech Connect (OSTI)

The CDF Central Preshower and Crack Detector Upgrade consist of scintillator tiles with embedded wavelength-shifting fibers, clear-fiber optical cables, and multi-anode photomultiplier readout. A description of the detector design, test results from R&D studies, and construction phase are reported. The upgrade was installed late in 2004, and a large amount of proton-antiproton collider data has been collected since then. Detector studies using those data are also discussed.

Artikov, A.; Boudagov, J.; Chokheli, D.; Drake, G.; Gallinaro, M.; Giunta, M.; Grudzinski, J.; Huston, J.; Iori, M.; Kim, D.; Kim, M.; /Dubna, JINR /Argonne /Rockefeller

2007-02-01T23:59:59.000Z

198

Immobilization of vanadia deposited on catalytic materials during carbo-metallic oil conversion  

SciTech Connect (OSTI)

This patent describes a process for the cracking of a hydrocarbon oil feed having a significant content of at least 0.1 ppm vanadium to lighter oil products. The process consists of contacting the feed under conversion conditions in a conversion zone with a catalyst containing a precipitated metal additive to immobilize vanadium compounds by forming compounds therewith that have melting points above temperatures found in regenerating a coked catalyst; and having catalytic cracking characteristics, coke and vanadium being deposited on the catalyst by the contact; regenerating the coked catalyst in the presence of an oxygen containing gas at a temperature sufficient to remove at least some of the coke, and, recycling the regenerated catalyst to the conversion zone for contact with fresh feed; the metal additive being present on the catalyst in an amount sufficient to immobilize at least a portion of the vanadium compound in the presence of the oxygen containing gas at the catalyst regeneration temperature; wherein the metal additive to immobilize vanadium compounds deposited on the catalyst is selected from the group consisting of Sr, Sc, Y, Nb, and Ta elements, and an element in the actinide series, or a combination of two or more of the elements.

Beck, H.W.; Carruthers, J.D.; Cornelius, E.B.; Hettinger, Jr., W.P.; Kovach, S.M.; Palmer, J.L.; Zandona, O.J.

1988-06-14T23:59:59.000Z

199

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

200

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

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201

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

202

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

203

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

204

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

205

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

206

Catalytic extraction processing of contaminated scrap metal  

SciTech Connect (OSTI)

Molten Metal Technology was awarded a contract to demonstrate the applicability of the Catalytic Extraction Process, a proprietary process that could be applied to US DOE`s inventory of low level mixed waste. This paper is a description of that technology, and included within this document are discussions of: (1) Program objectives, (2) Overall technology review, (3) Organic feed conversion to synthetic gas, (4) Metal, halogen, and transuranic recovery, (5) Demonstrations, (6) Design of the prototype facility, and (7) Results.

Griffin, T.P.; Johnston, J.E.; Payea, B.M.; Zeitoon, B.M.

1995-12-01T23:59:59.000Z

207

Preface: Challenges for Catalytic Exhaust Aftertreatment  

SciTech Connect (OSTI)

This special issue of Catalysis Today continues the tradition established since the 18th NAM in Cancun, 2003, of publishing the highlights coming from these catalytic after-treatment technologies sessions, where this volume contains 18 papers based on oral and poster presentations of the 23rd NAM, 2013. The guest editors would like to thank all of the catalyst scientists and engineers who presented in the "Emission control" sessions, and especially the authors who contributed to this special issue of Catalysis Today.

Nova, Isabella; Epling, Bill; Peden, Charles HF

2014-03-31T23:59:59.000Z

208

CYCLIC PLASTICITY OF A CRACKED STRUCTURE SUBJECTED TO MIXED MODE LOADING  

E-Print Network [OSTI]

CYCLIC PLASTICITY OF A CRACKED STRUCTURE SUBJECTED TO MIXED MODE LOADING Sylvie Pommier1, a 1 LMT, mixed mode crack propagation, plasticity, crack deflection. Abstract. Cyclic plasticity in the crack tip stresses in the overload's plastic zone. Moreover, if the overload's ratio is large enough, the crack may

209

LOW-FREQUENCY PHASED-ARRAY METHODS FOR CRACK DETECTION IN CAST AUSTENITIC PIPING COMPONENTS  

SciTech Connect (OSTI)

Studies at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, are being conducted to evaluate nondestructive examination (NDE) approaches for inspecting coarse-grained, austenitic stainless steel reactor components. The work provides information to the United States Nuclear Regulatory Commission (NRC) on the utility, effectiveness, limitations, and reliability of advanced inspection techniques for application on safety-related components in commercial nuclear power plants. This paper describes results from recent assessments using a low-frequency phased-array methodology for detecting cracks in cast austenitic piping welds. Piping specimens that contain thermal and mechanical fatigue cracks located adjacent to welds were examined. The specimens have surface geometrical conditions and weld features that simulate portions of primary piping systems in many U.S. pressurized water reactors (PWRs). In addition, segments of vintage centrifugally cast piping were examined to assess inherent acoustic noise and scattering due to grain structures and determine consistency of ultrasonic (UT) responses from varied circumferential locations. The phased-array UT methods were applied from the outside surface of the specimens using automated scanning devices and water coupling, and employed a modified instrument operating between 500 kHz and 1.0 MHz. Composite volumetric images of the specimens were generated. Results from laboratory studies for assessing crack detection and sizing effectiveness are discussed, including acoustic parameters observed in centrifugally cast piping base materials.

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

2008-01-01T23:59:59.000Z

210

P wave anisotropy, stress, and crack distribution at Coso geothermal...  

Open Energy Info (EERE)

Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: P wave anisotropy, stress, and crack distribution at Coso geothermal field, California...

211

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

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

Reveals Degradation Processes in Nuclear Reactor Structural Materials. Abstract: Corrosion and cracking represent critical failure mechanisms for structural materials in many...

212

Physics-Based Stress Corrosion Cracking Component Reliability  

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

Physics-Based Stress Corrosion Cracking Component Reliability Model cast in an R7-Compatible Cumulative Damage Framework Draft Report Supporting Technology Inputs to the Risk-...

213

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....

214

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...

215

Tribological Analysis of White Etching Crack (WEC) Failures in...  

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

Crack (WEC) Failures in Rolling Element Bearings Presented by Arnaud Ruellan, INSA de Lyon at the Wind Turbine Tribology Seminar 2014. 20141030NREL2014ArgonneRuellancomV...

216

Cracking in reinforced concrete bent caps  

E-Print Network [OSTI]

) . . . . . . . . . . . . . . . . 4. 2 Group It2 Response (Specimens 3C, 3D, 4C, 4E, 5D, 5E) . . . 4. 3 Group tt3 Response (Specimens 6F, 6G, 7F, 7H, 8G, 8H) . . . 4. 4 General Response 4. 5 Sununary. . . . . 49 . . . . 58 . . . . 64 70 . . . 75 5. STRUT-AND-TIE MODELING... be expressed as the product of the steel strain (s, ) at that level multiplied by the crack spacing (s, ); 20 w =z*s C S C (2. 6) a linear strain gradient can be used to project the maximum strain occurring at the level of the flexural reinforcement...

Young, Bradley S.

2000-01-01T23:59:59.000Z

217

3:2:1 Crack Spread  

Gasoline and Diesel Fuel Update (EIA)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"Click worksheet9,1,50022,3,,,,6,1,,781Title: Telephone:short version)ecTotal (Data from:2:1 Crack Spread

218

Crack opening area estimates in pressurized through-wall cracked elbows under bending  

SciTech Connect (OSTI)

One of the most important aspects in the leak-before-break approach is the estimation of the crack opening area corresponding to potential through-wall cracks at critical locations during plant operation. In order to provide a reasonable lower bound to the leak area under such loading conditions, numerous experimental and numerical programs have been developed in USA, U.K. and FRG and widely discussed in literature. This paper aims to extend these investigations on a class of pipe elbows characteristic of PWR main coolant piping. The paper is divided in three main parts. First, a new simplified estimation scheme for leakage area is described, based on the reference stress method. This approach mainly developed in U.K. and more recently in France provides a convenient way to account for the non-linear behavior of the material. Second, the method is carried out for circumferential through-wall cracks located in PWR elbows subjected to internal pressure. Finite element crack area results are presented and comparisons are made with our predictions. Finally, in the third part, the discussion is extended to elbows under combined pressure and in plane bending moment.

Franco, C.; Gilles, P.; Pignol, M.

1997-04-01T23:59:59.000Z

219

Composite tube cracking in kraft recovery boilers: A state-of-the-art review  

SciTech Connect (OSTI)

Beginning in the mid-1960s, increasing energy costs in Finland and Sweden made energy recovery more critical to the cost-effective operation of a kraft pulp mill. Boiler designers responded to this need by raising the steam operating pressure, but almost immediately the wall tubes in these new boilers began to corrode rapidly. Test panels installed in the walls of the most severely corroding boiler identified austenitic stainless steel as sufficiently resistant to the new corrosive conditions, and discussions with Sandvik AB, a Swedish tube manufacturer, led to the suggestion that coextruded tubes be used for water wall service in kraft recovery boilers. Replacement of carbon steel by coextruded tubes has solved most of the corrosion problems experienced by carbon steel wall tubes, however, these tubes have not been problem-free. Beginning in early 1995, a multidisciplinary research program funded by the US Department of Energy was established to investigate the cause of cracking in coextruded tubes and to develop improved materials for use in water walls and floors of kraft recovery boilers. One portion of that program, a state-of-the-art review of public- and private-domain documents related to coextruded tube cracking in kraft recovery boilers is reported here. Sources of information that were consulted for this review include the following: tube manufacturers, boiler manufacturers, public-domain literature, companies operating kraft recovery boilers, consultants and failure analysis laboratories, and failure analyses conducted specifically for this project. Much of the information contained in this report involves cracking problems experienced in recovery boiler floors and those aspects of spout and air-port-opening cracking not readily attributable to thermal fatigue. 61 refs.

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

1997-07-01T23:59:59.000Z

220

Study on Micro-scale Ceramic Catalytic Combustor with Embedded Heat Exchange Channels Takashi OKAMASA, Gwang-Goo LEE, Yuji SUZUKI, and Nobuhide KASAGI  

E-Print Network [OSTI]

Study on Micro-scale Ceramic Catalytic Combustor with Embedded Heat Exchange Channels Takashi combustion of butane is investigated. A cost-effective and robust ceramic combustor is developed using high anodic oxidation of aluminum layer. In order to increase the thermal efficiency, a combustor

Kasagi, Nobuhide

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

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...

222

Challenges in Catalytic Manufacture of Renewable Pyrrolidinones from Fermentation Derived Succinate  

SciTech Connect (OSTI)

Fermentation derived succinic acid ammonium salt is an ideal precursor for manufacture of renewable N-methyl pyrrolidinone (NMP) or 2-pyrrolidinone (2P) via heterogeneous catalysis. However, there are many challenges to making this a practical reality. Chief among the challenges is avoiding catalyst poisoning by fermentation by- and co-products. Battelle / Pacific Northwest National Laboratory (PNNL) have developed an economically effective technology strategy for this purpose. The technology is a combination of purely thermal processing, followed by simple catalytic hydrogenation that together avoids catalyst poisoning from fermentation impurities and provides high selectivity and yields of NMP or 2P.

White, James F.; Holladay, Johnathan E.; Zacher, Alan H.; Frye, John G.; Werpy, Todd A.

2014-09-05T23:59:59.000Z

223

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

224

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

225

NORTHWESTERN UNIVERSITY Crack Response to Weather Effects, Blasting, and Construction  

E-Print Network [OSTI]

NORTHWESTERN UNIVERSITY Crack Response to Weather Effects, Blasting, and Construction Vibrations Acknowledgements iii Abstract iv List of Figures v List of Tables xi Chapter 1- Introduction 1 Chapter 2- Blast Vibration Response, Southbury, Connecticut 5 Structural Description Instrumentation Blast Response Crack

226

Crack-based analysis of concrete with brittle reinforcement  

E-Print Network [OSTI]

{ FaberMaunsell Ltd; University of Cambridge Brittle reinforcement (such as fibre-reinforced plastic to the surround- ing concrete, at a crack surface sL=sR s on the left/right side of a crack u increase in unbonded

Burgoyne, Chris

227

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

228

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

229

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)...

230

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...

231

Selective Catalytic Reduction and Exhaust Gas Recirculation Systems...  

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

Reduction and Exhaust Gas Recirculation Systems Optimization Selective Catalytic Reduction and Exhaust Gas Recirculation Systems Optimization A patented EGR-SCR approach was shown...

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

Piloted rich-catalytic lean-burn hybrid combustor  

DOE Patents [OSTI]

A catalytic combustor assembly which includes, an air source, a fuel delivery means, a catalytic reactor assembly, a mixing chamber, and a means for igniting a fuel/air mixture. The catalytic reactor assembly is in fluid communication with the air source and fuel delivery means and has a fuel/air plenum which is coated with a catalytic material. The fuel/air plenum has cooling air conduits passing therethrough which have an upstream end. The upstream end of the cooling conduits is in fluid communication with the air source but not the fuel delivery means.

Newburry, Donald Maurice (Orlando, FL)

2002-01-01T23:59:59.000Z

234

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

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

Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005deermarshall.pdf More Documents & Publications Bifunctional Catalysts for the Selective Catalytic...

235

Catalytic Upgrading of Sugars to Hydrocarbons Technology Pathway...  

Energy Savers [EERE]

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

236

SciTech Connect: Stress corrosion cracking of alloy 600 using...  

Office of Scientific and Technical Information (OSTI)

Stress corrosion cracking of alloy 600 using the constant strain rate test Citation Details In-Document Search Title: Stress corrosion cracking of alloy 600 using the constant...

237

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....

238

E-Print Network 3.0 - automated crack inspection Sample Search...  

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

through micro cracks in the composite material... system with micro cracking induced damage is carried out. The effective permeability due ... Source: Popov, Peter - Institute of...

239

Catalytic multi-stage liquefaction (CMSL)  

SciTech Connect (OSTI)

Under contract with the U.S. Department of Energy, Hydrocarbon Technologies, Inc. has conducted a series of eleven catalytic, multi-stage, liquefaction (CMSL) bench scale runs between February, 1991, and September, 1995. The purpose of these runs was to investigate novel approaches to liquefaction relating to feedstocks, hydrogen source, improved catalysts as well as processing variables, all of which are designed to lower the cost of producing coal-derived liquid products. This report summarizes the technical assessment of these runs, and in particular the evaluation of the economic impact of the results.

Comolli, A.G.; Ganguli, P.; Karolkiewicz, W.F.; Lee, T.L.K.; Pradhan, V.R.; Popper, G.A.; Smith, T.; Stalzer, R.

1996-11-01T23:59:59.000Z

240

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

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

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]

performed as a function of mechanical inplane strain levels, heating rates, and number of thermal cycles. The apparatus generated cracks related to the in-plane stresses (or strains) on plies. The design and analysis concept of the synergistic stress...

Ju, Jaehyung

2006-10-30T23:59:59.000Z

242

Methods for preparation of catalytic materials  

SciTech Connect (OSTI)

To establish guidelines for the development of a scientific basis for catalyst preparation is perhaps a very ambitious goal. One would re required first to answer the following rhetorical questions: what are the properties which determine the performance of a catalytic material; how can these properties be introduced, developed, and/or improved during preparation? The answer to these questions involves a comprehensive discussion of the theories of catalysis, which is beyond the scope of this review. The authors will attempt, instead, to provide a rationale for each reader to answer these questions on the basis of his/her own interests. They start the discussion by describing the fundamental steps in producing bulk catalysts and/or catalyst supports. The fundamental processes involved are those derived from traditional three-dimensional chemistry. The topic areas will include single-component and multicomponent metal oxides. Unsupported metallic catalysts are formed by transformations involving physical or chemical processes, and the preparation methods for this class of materials will be discussed next. Attention will then turn to the preparation of supported catalytic materials. The main topics to be discussed will be those related to the interaction between the support and the active phase when they are put together to generate the catalyst. In this approach, the authors exploit the virtually unexplored field of surface, or two-dimensional, physical chemistry. The materials considered include dispersed metals and alloys and composite oxides. 366 refs.

Schwarz, J.A. [Syracuse Univ., NY (United States). Dept. of Chemical Engineering and Materials Science; Contescu, C.; Contescu, A. [Romanian Academy, Bucharest (Romania). Inst. of Physical Chemistry

1995-05-01T23:59:59.000Z

243

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

244

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

245

Implications of early stages in the growth of stress corrosion cracking on component reliability  

SciTech Connect (OSTI)

Environment-induced crack growth generally progresses through several stages prior to component failure. Crack initiation, short crack growth, and stage 1 growth are early stages in crack development that are summarized in this paper. The implications of these stages on component reliability, derive from the extended time that the crack exists in the early stages because crack velocity is slow. The duration of the early stages provides a greater opportunity for corrective action if cracks can be detected. Several important factors about the value of understanding short crack behavior include: (1) life prediction requires a knowledge of the total life cycle of the crack including the early stages, (2) greater reliability is possible if the transition between short and long crack behavior is known component life after this transition is short and (3) remedial actions are more effective for short than long cracks.

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

1995-04-01T23:59:59.000Z

246

Structural, compositional, and photoluminescence characterization of thermal chemical vapor deposition-grown Zn{sub 3}N{sub 2} microtips  

SciTech Connect (OSTI)

The catalytic growth of Zn{sub 3}N{sub 2} using guided-stream thermal chemical vapor deposition has been investigated within the parameter range of acicular growth to obtain uniform microtips with a high crystalline quality. The cubic anti-bixbyite crystal structure of Zn{sub 3}N{sub 2} microtips and its related phonon mode are revealed by X-ray diffraction and Raman spectroscopy, respectively. The surface morphologies of pure and surface-oxidized Zn{sub 3}N{sub 2} microtips are depicted by scanning electron microscopy and show the crack formation on the surface-oxidized Zn{sub 3}N{sub 2} microtips. The spatial element distribution map confirms the VLS growth mechanism for Zn{sub 3}N{sub 2} microtips and reveals the depth profile of zinc, nitrogen, oxygen, and nickel elements. Photoluminescence (PL) spectra of Zn{sub 3}N{sub 2} microtips show a sharp infrared band-to-band emission peak at 1.34?eV with a full width at half maximum of ?100?meV and a very broad oxygen-related defect band emission peak centered at ?0.85?eV.

Wei, Pai-Chun, E-mail: pcwei68@gmail.com, E-mail: tsengcm@phys.sinica.edu.tw; Chang, Chung-Chieh; Hsu, Chia-Hao [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Tong, Shih-Chang; Shen, Ji-Lin [Department of Physics, Chung Yuan Christian University, Chung-Li 32023, Taiwan (China); Tseng, Chuan-Ming, E-mail: pcwei68@gmail.com, E-mail: tsengcm@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Institute of Materials Science and Engineering, National Central University, Tao-Yuan 32001, Taiwan (China)

2014-10-14T23:59:59.000Z

247

Ability of Catalytic Converters to Reduce Air Pollution  

E-Print Network [OSTI]

NOx - 1 Ability of Catalytic Converters to Reduce Air Pollution MEASUREMENT OF SELECTED AIR POLLUTANTS IN CAR EXHAUST Last updated: June 17, 2014 #12;NOx - 2 Ability of Catalytic Converters to Reduce Air Pollution MEASUREMENT OF SELECTED AIR POLLUTANTS IN CAR EXHAUST INTRODUCTION Automobile engines

Nizkorodov, Sergey

248

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

249

Preparation and characterization of VOx/TiO2 catalytic coatings on stainless steel plates for structured catalytic reactors.  

E-Print Network [OSTI]

for structured catalytic reactors. Thierry Giornelli, Axel Löfberg* and Elisabeth Bordes-Richard Unité de.Lofberg@univ-lille1.fr Abstract The parameters to be controlled to coat metallic walls by VOx/TiO2 catalysts which) was chosen because of its large application in industrial catalytic reactors. TiO2 films on stainless steel

Boyer, Edmond

250

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

251

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

252

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

253

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

254

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

255

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

256

Catalytic carbon membranes for hydrogen production  

SciTech Connect (OSTI)

Commercial carbon composite microfiltration membranes may be modified for gas separation applications by providing a gas separation layer with pores in the 1- to 10-nm range. Several organic polymeric precursors and techniques for depositing a suitable layer were investigated in this project. The in situ polymerization technique was found to be the most promising, and pure component permeation tests with membrane samples prepared with this technique indicated Knudsen diffusion behavior. The gas separation factors obtained by mixed-gas permeation tests were found to depend strongly on gas temperature and pressure indicating significant viscous flow at high-pressure conditions. The modified membranes were used to carry out simultaneous water gas shift reaction and product hydrogen separation. These tests indicated increasing CO conversions with increasing hydrogen separation. A simple process model was developed to simulate a catalytic membrane reactor. A number of simulations were carried out to identify operating conditions leading to product hydrogen concentrations over 90 percent. (VC)

Damle, A.S.; Gangwal, S.K.

1992-01-01T23:59:59.000Z

257

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

258

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...

259

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

260

PLASMA Approximate Dynamic Programming finally cracks the locomotive optimization problem  

E-Print Network [OSTI]

PLASMA ­ Approximate Dynamic Programming finally cracks the locomotive optimization problem schedules and new operating policies. PLASMA is currently running at Norfolk Southern for strategic of PLASMA: Each locomotive is modeled individually, making it possible to capture both horsepower

Powell, Warren B.

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

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

262

Assessment of crack opening area for leak rates  

SciTech Connect (OSTI)

This paper outlines the background to recommended crack opening area solutions given in a proposed revision to leak before break guidance for the R6 procedure. Comparisons with experimental and analytical results are given for some selected cases of circumferential cracks in cylinders. It is shown that elastic models can provide satisfactory estimations of crack opening displacement (and area) but they become increasingly conservative for values of L{sub r} greater than approximately 0.4. The Dugdale small scale yielding model gives conservative estimates of crack opening displacement with increasing enhancement for L{sub r} values greater than 0.4. Further validation of the elastic-plastic reference stress method for up to L{sub r} values of about 1.0 is presented by experimental and analytical comparisons. Although a more detailed method, its application gives a best estimate of crack opening displacement which may be substantially greater than small scale plasticity models. It is also shown that the local boundary conditions in pipework need to be carefully considered when evaluating crack opening area for through-wall bending stresses resulting from welding residual stresses or geometry discontinuities.

Sharples, J.K.; Bouchard, P.J.

1997-04-01T23:59:59.000Z

263

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

264

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

265

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

266

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

267

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

268

Crack growth rates and fracture toughness of irradiated austenitic stainless steels in BWR environments.  

SciTech Connect (OSTI)

In light water reactors, austenitic stainless steels (SSs) are used extensively as structural alloys in reactor core internal components because of their high strength, ductility, and fracture toughness. However, exposure to high levels of neutron irradiation for extended periods degrades the fracture properties of these steels by changing the material microstructure (e.g., radiation hardening) and microchemistry (e.g., radiation-induced segregation). Experimental data are presented on the fracture toughness and crack growth rates (CGRs) of wrought and cast austenitic SSs, including weld heat-affected-zone materials, that were irradiated to fluence levels as high as {approx} 2x 10{sup 21} n/cm{sup 2} (E > 1 MeV) ({approx} 3 dpa) in a light water reactor at 288-300 C. The results are compared with the data available in the literature. The effects of material composition, irradiation dose, and water chemistry on CGRs under cyclic and stress corrosion cracking conditions were determined. A superposition model was used to represent the cyclic CGRs of austenitic SSs. The effects of neutron irradiation on the fracture toughness of these steels, as well as the effects of material and irradiation conditions and test temperature, have been evaluated. A fracture toughness trend curve that bounds the existing data has been defined. The synergistic effects of thermal and radiation embrittlement of cast austenitic SS internal components have also been evaluated.

Chopra, O. K.; Shack, W. J.

2008-01-21T23:59:59.000Z

269

Multiple use of waste catalysts with and without regeneration for waste polymer cracking  

SciTech Connect (OSTI)

Waste plastics contain a substantial number of valuable chemicals. The wastes from post-consumer as well as from industrial production can be recycled to valuable chemical feedstock, which can be used in refineries and/or petrochemical industries. This chemical recycling process is an ideal approach in recycling the waste for a better environment. Polymer cracking using a laboratory fluidised bed reactor concentrated on the used highly contaminated catalyst, E-Cat 2. Even though E-Cat 2 had low activity due to fewer acid sites, the products yielded were similar with amorphous ASA and were far better than thermal cracking. The high levels of heavy metals, namely nickel and vanadium, deposited during their lifetime as an FCC catalyst, did not greatly affect on the catalyst activity. It was also shown that E-Cat 2 could be used with and without regeneration. Although there was more deactivation when there was no regeneration step, the yield of gases (C{sub 2}-C{sub 7}) remained fairly constant. For the first time, these results indicate that 'waste' FCC catalyst (E-Cat) is a good candidate for future feedstock recycling of polymer waste. The major benefits of using E-Cat are a low market price, the ability to tolerate reuse and regeneration capacity.

Salmiaton, A., E-mail: mie@eng.upm.edu.my [Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia (UPM), 43400 UPM Serdang, Selangor (Malaysia); Garforth, A.A. [School of Chemical Engineering and Analytical Science, University of Manchester, P.O. Box 88, Sackville Street, Manchester M60 1QD (United Kingdom)

2011-06-15T23:59:59.000Z

270

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

271

atp catalytic domain: Topics by E-print Network  

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

produc Kik, Pieter 328 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

272

acidic multimetallic catalytic: Topics by E-print Network  

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

produc Kik, Pieter 106 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

273

automobile catalytic converters: Topics by E-print Network  

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

Odei 2006-01-01 408 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

274

atp catalytic cycle: Topics by E-print Network  

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

produc Kik, Pieter 275 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

275

advanced catalytic hydrogenation: Topics by E-print Network  

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

produc Kik, Pieter 188 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

276

apparent catalytic site: Topics by E-print Network  

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

produc Kik, Pieter 257 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

277

advanced catalytic materials: Topics by E-print Network  

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

produc Kik, Pieter 225 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

278

acrylamide catalytically inhibits: Topics by E-print Network  

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

produc Kik, Pieter 78 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

279

assisted catalytic oxidation: Topics by E-print Network  

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

produc Kik, Pieter 251 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

280

active catalytic sites: Topics by E-print Network  

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

produc Kik, Pieter 337 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

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

atpase catalytic domain: Topics by E-print Network  

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

produc Kik, Pieter 266 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

282

advanced catalytic materials 1996: Topics by E-print Network  

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

produc Kik, Pieter 467 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

283

archaeal primase catalytic: Topics by E-print Network  

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

produc Kik, Pieter 92 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

284

advanced catalytic science: Topics by E-print Network  

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

produc Kik, Pieter 488 Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine MIT - DSpace Summary: As part of the MIT micro-gas turbine engine...

285

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...

286

Hydrogen permeable protective coating for a catalytic surface  

DOE Patents [OSTI]

A protective coating for a surface comprising a layer permeable to hydrogen, said coating being deposited on a catalyst layer; wherein the catalytic activity of the catalyst layer is preserved.

Liu, Ping (Irvine, CA); Tracy, C. Edwin (Golen, CO); Pitts, J. Roland (Lakewood, CO); Lee, Se-Hee (Lakewood, CO)

2007-06-19T23:59:59.000Z

287

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...

288

Catalytic H2O2 decomposition on palladium surfaces  

E-Print Network [OSTI]

The catalytic decomposition of H?O? at smooth single-crystal and polycrystalline palladium surfaces that had been subjected to various surface modifications has been studied. Monolayer and submonolayer coverages of I, Br and Cl adsorbates were used...

Salinas, S. Adriana

1998-01-01T23:59:59.000Z

289

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

290

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

291

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

292

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

293

Catalytic Upgrading of Sugars to Hydrocarbons Technology Pathway  

SciTech Connect (OSTI)

This technology pathway case investigates the catalytic conversion of solubilized carbohydrate streams to hydrocarbon biofuels, utilizing data from recent efforts within the National Advanced Biofuels Consortium (NABC) in collaboration with Virent, Inc. Technical barriers and key research needs that should be pursued for the catalytic conversion of sugars pathway to be competitive with petroleum-derived gasoline-, diesel-, and jet-range hydrocarbon blendstocks have been identified.

Biddy, M.; Jones, S.

2013-03-01T23:59:59.000Z

294

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

295

High-Resolution Characterizations of Stress-Corrosion Cracks in Austenitic Stainless Steel from Crack Growth Tests in BWR-Simulated Environments  

SciTech Connect (OSTI)

Mechanisms controlling environmental degradation and cracking in light-water-reactor (LWR) systems have been investigated by analytical transmission electron microscopy (ATEM) of cracks and crack tips. The current work focuses on intergranular stress corrosion cracking (IGSCC) of 300-series, austenitic stainless steels in high-temperature LWR environments. Comparisons are made between cold-worked 304SS containing stress-corrosion cracks produced in a simulated boiling-water-reactor (BWR) environment during crack-growth tests, and a 304SS core component with cracks produced during 26-year BWR service. Similar corrosion products consisting of duplex-layered spinel oxides were found along the walls of open cracks in the service and laboratory test samples. These oxide films consisted of oriented Cr-rich spinel up to ~30 nm thick along the metal crack walls and large-grained Fe-rich spinel at the crack centers. Cracks in the service sample were generally more filled with oxide, perhaps reflecting the much longer times available for corrosion to occur after the crack passage. Crack tips in the BWR top-guide sample exhibited unique and unexpected structures with oxide-filled cracks <10 nm wide ending in finger-like attack and locally “dealloyed” zones of Fe/Cr-depleted, Ni-rich metal. Alloy compositions measured at numerous crack tips were 40 wt% Fe, 4 wt% Cr and 55 wt% Ni immediately ahead of the degradation front versus approximately 70 wt% Fe, 19 wt% Cr and 9 wt% Ni in the bulk 304SS. Laboratory samples with cracks grown over much shorted times (~1.5 months) did not show the distinctive crack tip structures or strong Ni enrichment in the metal ahead of the crack tips as for the service sample. This suggests that although selective oxidation processes occur during degradation, significant composition differences may only develop after crack propagation has slowed or stopped. Additional nanometer-scale measurements elucidating corrosion processes occurring during crack advance are presented to provide insights into mechanisms controlling IGSCC.

Bruemmer, Stephen M.; Thomas, Larry E.

2005-07-20T23:59:59.000Z

296

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

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

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

300

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

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

Reflective Cracking Study: First-level Report on HVS Testing on Section 588RF - 90 mm AR4000-DOverlay  

E-Print Network [OSTI]

testing being performed to validate Caltrans overlay strategies for the rehabilitation of cracked asphalt concrete.concrete. It describes the results of the fourth HVS reflective cracking testingconcrete. It describes the results of the fourth HVS reflective cracking testing

Jones, David; Wu, R; Harvey, John T

2008-01-01T23:59:59.000Z

302

Reflective Cracking Study: First-Level Report on HVS Testing on Section 590RF - 90 mm MB4-G Overlay  

E-Print Network [OSTI]

testing being performed to validate Caltrans overlay strategies for the rehabilitation of cracked asphalt concrete.concrete. It describes the results of the first HVS reflective cracking testingconcrete. It describes the results of the first HVS reflective cracking testing

Jones, David; Tsai, Bor-Wen; Harvey, John T

2008-01-01T23:59:59.000Z

303

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

304

Stress relief cracking in creep resisting low alloy ferritic steels.  

E-Print Network [OSTI]

, for their inspiration by example, to Messrs. R.Turkentine, S. Charter, D. Evans, P.Hull and D.Duke, for their guidance and assistfu.ce during all stages of the experi- mental work; also to Professor G.S.Kent, Dr.M.N.Mct1orris, Professor T.P.Hughes, Dr... >eased and inter>granular> cavitation cracking increased. Indeed the mixed upper> and lower> bainite matr>ix pr>oduced by oil quenching, showed ver>y br>ittle behaviOUr> associated with little opening of the intergranular cr>acKs. The implication...

Tait, Robert Andrew

1976-10-26T23:59:59.000Z

305

Stress Corrosion Crack Detection on HU-25 Guardian Aircraft  

SciTech Connect (OSTI)

Several ultrasonic inspection methods were developed at the Federal Aviation Administration's Airworthiness Assurance NDI Validation Center (AANC) to easily and rapidly detect hidden stress corrosion cracks in all vertical windshield posts on the US Coast Guard (USCG) HU-25 Guardian aircraft. The inspection procedure locates cracks as small as 2.0 millimeters emanating from internal fastener holes and determines their length. A test procedure was developed and a baseline assessment of the USCG fleet was conducted. Inspection results on twenty-five aircraft revealed a good correlation with results made during subsequent structural disassembly and visual inspection.

Blackmon, R.; Huffman, J.; Mello, C.W.; Moore, D.G.; Walkington, P.D.

1999-02-17T23:59:59.000Z

306

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

307

Stress Corrosion Cracking and Delayed Increase in Penetration Resistance after Dynamic Compaction of Sand  

E-Print Network [OSTI]

Stress Corrosion Cracking and Delayed Increase in Penetration Resistance after Dynamic Compaction on the process of stress corrosion cracking of the micro-morphological features on the surface of the sand grains

Michalowski, Radoslaw L.

308

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...

309

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

310

AQUIFER THERMAL ENERGY STORAGE  

E-Print Network [OSTI]

aquifers for thermal energy storage. Problems outlined aboveModeling of Thermal Energy Storage in Aquifers," Proceed-ings of Aquifer Thermal Energy Storage Workshop, Lawrence

Tsang, C.-F.

2011-01-01T23:59:59.000Z

311

AQUIFER THERMAL ENERGY STORAGE  

E-Print Network [OSTI]

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

Tsang, C.-F.

2011-01-01T23:59:59.000Z

312

Ultra Low NOx Catalytic Combustion for IGCC Power Plants  

SciTech Connect (OSTI)

In order to meet DOE's goals of developing low-emissions coal-based power systems, PCI has further developed and adapted it's Rich-Catalytic Lean-burn (RCL{reg_sign}) catalytic reactor to a combustion system operating on syngas as a fuel. The technology offers ultra-low emissions without the cost of exhaust after-treatment, with high efficiency (avoidance of after-treatment losses and reduced diluent requirements), and with catalytically stabilized combustion which extends the lower Btu limit for syngas operation. Tests were performed in PCI's sub-scale high-pressure (10 atm) test rig, using a two-stage (catalytic then gas-phase) combustion process for syngas fuel. In this process, the first stage consists of a fuel-rich mixture reacting on a catalyst with final and excess combustion air used to cool the catalyst. The second stage is a gas-phase combustor, where the air used for cooling the catalyst mixes with the catalytic reactor effluent to provide for final gas-phase burnout and dilution to fuel-lean combustion products. During testing, operating with a simulated Tampa Electric's Polk Power Station syngas, the NOx emissions program goal of less than 0.03 lbs/MMBtu (6 ppm at 15% O{sub 2}) was met. NOx emissions were generally near 0.01 lbs/MMBtu (2 ppm at 15% O{sub 2}) (PCI's target) over a range on engine firing temperatures. In addition, low emissions were shown for alternative fuels including high hydrogen content refinery fuel gas and low BTU content Blast Furnace Gas (BFG). For the refinery fuel gas increased resistance to combustor flashback was achieved through preferential consumption of hydrogen in the catalytic bed. In the case of BFG, stable combustion for fuels as low as 88 BTU/ft{sup 3} was established and maintained without the need for using co-firing. This was achieved based on the upstream catalytic reaction delivering a hotter (and thus more reactive) product to the flame zone. The PCI catalytic reactor was also shown to be active in ammonia reduction in fuel allowing potential reductions in the burner NOx production. These reductions of NOx emissions and expanded alternative fuel capability make the rich catalytic combustor uniquely situated to provide reductions in capital costs through elimination of requirements for SCR, operating costs through reduction in need for NOx abating dilution, SCR operating costs, and need for co-firing fuels allowing use of lower value but more available fuels, and efficiency of an engine through reduction in dilution flows.

Shahrokh Etemad; Benjamin Baird; Sandeep Alavandi; William Pfefferle

2008-03-31T23:59:59.000Z

313

Correlations between surface structure and catalytic activity/selectivity  

SciTech Connect (OSTI)

Objective is to address the keys to understanding the relation between surface structure and catalytic activity/selectivity. Of concern are questions related to enhanced catalytic properties of mixed-metal catalysts and critical active site requirements for molecular synthesis and rearrangement. The experimental approach utilizes a microcatalytic reactor contiguous to a surface analysis system, an arrangement which allows in vacuo transfer of the catalyst from one chamber to the other. Surface techniques being used include Auger (AES), UV and X-ray photoemission spectroscopy (UPS and XPS), temperature programmed desorption (TPD), low energy electron diffraction (LEED), high resolution electron energy loss spectroscopy (HREELS) and infrared reflection-absorption spectroscopy (IRAS). Our research program builds upon our previous experience relating the results of single crystal kinetic measurements with the results obtained with supported analogs. As well we are exploiting our recent work on the preparation, the characterization, and the determination of the catalytic properties of ultra-thin metal and metal oxide films. The program is proceeding toward the study of the unique catalytic properties of ultrathin metal films; the investigation of the critical ensemble size requirements for principal catalytic reaction types; and the modelling of supported catalysts using ultra-thin planar oxide surfaces.

Goodman, D.W.

1992-10-01T23:59:59.000Z

314

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

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

with an initial crack. Constant ... Source: Fatemi, Ali - Department of Mechanical, Industrial and Manufacturing Engineering, University of Toledo Collection: Materials...

315

Thin film cracking and ratcheting caused by temperature cycling  

E-Print Network [OSTI]

Thin film cracking and ratcheting caused by temperature cycling M. Huang and Z. Suo Mechanical caused by ratcheting in an adjacent ductile layer. For example, on a silicon die directly attached corners. Aided by cycling temperature, the shear stresses cause ratcheting in the aluminum pads

Suo, Zhigang

316

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

317

Method of making crack-free zirconium hydride  

DOE Patents [OSTI]

Crack-free hydrides of zirconium and zirconium-uranium alloys are produced by alloying the zirconium or zirconium-uranium alloy with beryllium, or nickel, or beryllium and scandium, or nickel and scandium, or beryllium and nickel, or beryllium, nickel and scandium and thereafter hydriding.

Sullivan, Richard W. (Denver, CO)

1980-01-01T23:59:59.000Z

318

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

319

MATHEMATICAL MODEL OF DELAMINATION CRACKS ON IMPERFECT INTERFACES  

E-Print Network [OSTI]

monolith combustors that are being incorporated into new proto-type designs of gas turbines. The 1 #12. In the application in a gas turbine combustor, temperatures of the catalyst layer could vary from ambient conditionsMATHEMATICAL MODEL OF DELAMINATION CRACKS ON IMPERFECT INTERFACES Y. A. Antipov 1 , O. Avila

Bath, University of

320

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.

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

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

322

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

323

A creep model for austenitic stainless steels incorporating cavitation and wedge cracking  

E-Print Network [OSTI]

A creep model for austenitic stainless steels incorporating cavitation and wedge cracking S Mahesh evolution in the form of cavitation and wedge- cracking on grain boundary facets is considered. Both: Austenitic stainless steel, creep, grain boundary sliding, cavitation, wedge- cracking. Submitted to

Mahesh, Sivasambu

324

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

325

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

326

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

327

Method for measuring recovery of catalytic elements from fuel cells  

DOE Patents [OSTI]

A method is provided for measuring the concentration of a catalytic clement in a fuel cell powder. The method includes depositing on a porous substrate at least one layer of a powder mixture comprising the fuel cell powder and an internal standard material, ablating a sample of the powder mixture using a laser, and vaporizing the sample using an inductively coupled plasma. A normalized concentration of catalytic element in the sample is determined by quantifying the intensity of a first signal correlated to the amount of catalytic element in the sample, quantifying the intensity of a second signal correlated to the amount of internal standard material in the sample, and using a ratio of the first signal intensity to the second signal intensity to cancel out the effects of sample size.

Shore, Lawrence (Edison, NJ); Matlin, Ramail (Berkeley, NJ)

2011-03-08T23:59:59.000Z

328

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

329

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

330

Thermal Stress Cracking of Sliding Gate Plates Hyoung-Jun Lee1  

E-Print Network [OSTI]

, Warrendale, PA. #12;may b aspira b). Th indica show Previ their differ tempe mech [1]. A pressu be very

Thomas, Brian G.

331

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

332

FURTHER EXAMINATION OF CRACK TIP MICROSTRUCTURES IN F82H ON THE LOWER SHELF  

SciTech Connect (OSTI)

Dislocation microstructures have been further examined near the crack tip of a compact tension specimen of unirradiated F82H loaded to 25.6 MPa m square root at –196 degrees C after fatigue precracking. A specimen was prepared by sectioning, dimple grinding and ion milling to produce electron transparency just ahead of the crack tip. Further ion milling has allowed improved examination of the microstructure immediately ahead of the crack tip. It is found that subgrain structure is relatively unaffected near the crack tip whereas 3 micron from the crack tip, dislocation loop structure was identified.

Gelles, David S.; Odette, George R.; Spatig, P.

2003-09-03T23:59:59.000Z

333

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

334

5 Hz Catalytic Emissions FT-IR Monitoring during Lean-Rich Engine...  

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

Hz Catalytic Emissions FT-IR Monitoring during Lean-Rich Engine Cycles: Comparison to Reference Methods 5 Hz Catalytic Emissions FT-IR Monitoring during Lean-Rich Engine Cycles:...

335

Bioenergy Technologies Office R&D Pathways: In-Situ Catalytic...  

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

Office R&D Pathways: In-Situ Catalytic Fast Pyrolysis The in-situ catalytic fast pyrolysis pathway involves rapidly heating biomass with a catalyst to create bio-oils,...

336

Bioenergy Technologies Office R&D Pathways: Ex-Situ Catalytic...  

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

Office R&D Pathways: Ex-Situ Catalytic Fast Pyrolysis In ex-situ catalytic fast pyrolysis, biomass is heated with catalysts to create bio-oils, which are then used to...

337

Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine  

E-Print Network [OSTI]

As part of the MIT micro-gas turbine engine project, the development of a hydrocarbon-fueled catalytic micro-combustion system is presented. A conventionally-machined catalytic flow reactor was built to simulate the ...

Peck, Jhongwoo, 1976-

2003-01-01T23:59:59.000Z

338

Model catalytic studies of single crystal, polycrystalline metal, and supported catalysts  

E-Print Network [OSTI]

This dissertation is focused on understanding the structure-activity relationship in heterogeneous catalysis by studying model catalytic systems. The catalytic oxidation of CO was chosen as a model reaction for studies on a variety of catalysts. A...

Yan, Zhen

2009-05-15T23:59:59.000Z

339

Continued investigations of the catalytic reduction of N? to NH? by molybdenum triamidoamine complexes  

E-Print Network [OSTI]

A study of the effects of employing different solvents and the introduction of dihydrogen during the catalytic reduction of dinitrogen to ammonia with [HIPTN 3N]Mo complexes was completed. During a catalytic reaction, the ...

Hanna, Brian S. (Brian Stewart)

2011-01-01T23:59:59.000Z

340

Methods of using structures including catalytic materials disposed within porous zeolite materials to synthesize hydrocarbons  

DOE Patents [OSTI]

Catalytic structures include a catalytic material disposed within a zeolite material. The catalytic material may be capable of catalyzing a formation of methanol from carbon monoxide and/or carbon dioxide, and the zeolite material may be capable of catalyzing a formation of hydrocarbon molecules from methanol. The catalytic material may include copper and zinc oxide. The zeolite material may include a first plurality of pores substantially defined by a crystal structure of the zeolite material and a second plurality of pores dispersed throughout the zeolite material. Systems for synthesizing hydrocarbon molecules also include catalytic structures. Methods for synthesizing hydrocarbon molecules include contacting hydrogen and at least one of carbon monoxide and carbon dioxide with such catalytic structures. Catalytic structures are fabricated by forming a zeolite material at least partially around a template structure, removing the template structure, and introducing a catalytic material into the zeolite material.

Rollins, Harry W. (Idaho Falls, ID); Petkovic, Lucia M. (Idaho Falls, ID); Ginosar, Daniel M. (Idaho Falls, ID)

2011-02-01T23:59:59.000Z

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.


341

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...

342

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

343

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

344

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat PumpRecord ofESPCof Energy 12,Materials | Department of

345

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

346

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

347

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

348

Catalytic, Enantioselective Alkylations of N,O-Acetals  

E-Print Network [OSTI]

, 10998-10999. (2) Hoveyda et al. have developed a Ni-catalyzed alkylation reaction of allylic acetalsCatalytic, Enantioselective Alkylations of N,O-Acetals Dana Ferraris, Travis Dudding, Brandon Young alkylation reactions of acetals have attained a prominent position in organic synthesis.1 Methods employing

Lectka, Thomas

349

Catalytic Asymmetric Synthesis of Hydroxy Enol Ethers: Approach to a  

E-Print Network [OSTI]

for the generation of polypro- pionate backbone.1-7 In contrast, the asymmetric acetate aldol reaction that leads associated with acetate aldol reactions have prompted investigations into alternative methods to generate the catalytic asymmetric allylation of aldehydes followed by oxidative cleavage of the allyl group (Scheme 1, A

Walsh, Patrick J.

350

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

351

Structural Dynamics of a Catalytic Monolayer Probed by Ultrafast  

E-Print Network [OSTI]

REPORTS Structural Dynamics of a Catalytic Monolayer Probed by Ultrafast 2D IR Vibrational Echoes in solutions. Here, we extend the technique to probing the interfacial dynamics and structure of a silica. The structural dynamics, as reported on by a carbonyl stretch vibration of the surface-bound complex, have

Fayer, Michael D.

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

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

354

Catalytic Methane Reduction in the Exhaust Gas of Combustion Engines  

E-Print Network [OSTI]

Catalytic Methane Reduction in the Exhaust Gas of Combustion Engines Peter Mauermann1,* , Michael Dornseiffer6 , Frank Amkreutz6 1 Institute for Combustion Engines , RWTH Aachen University, Schinkelstr. 8, D of the hydrocarbon exhaust of internal combustion engines. In contrast to other gaseous hydrocarbons, significant

Dunin-Borkowski, Rafal E.

355

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.

356

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

357

Initiation of environmentally-assisted cracking in low-alloy steels  

SciTech Connect (OSTI)

Environmentally-Assisted Cracking (EAC) in low alloy steels is activated by a critical level of sulfide ions at the crack tip, which is produced from dissolution of sulfide inclusions (MnS, FeS, etc.) in the steel following exposure by a growing crack. EAC of concern herein is the increase of fatigue crack growth rate of up to 40 to 100 times the rate in air that occurs at 240--300 C in high temperature LWR or boiler water environments. The initiation of EAC is the onset of the higher fatigue crack growth rates in fully developed cracks already presumed to be present due to fatigue, stress corrosion cracking, or induced by fabrication. Initiation of EAC is induced by a change in loading parameters causing the fatigue crack growth rate to increase from a small multiple (2--4) to 40--100 times the air rate. A steady state theory developed by Combrade, suggests that EAC will initiate only above a critical crack velocity and cease below this same velocity. However, more recent tests show that EAC can persist down to much lower velocities (100 times lower) in low oxygen water at slightly lower temperatures. A special set of experiments on high sulfur plate material demonstrate that EAC will not initiate from surface cracks with low sulfide inventories at low crack tip velocities. Transient diffusion calculations show that a finite crack extension at a high crack tip velocity is necessary to initiate EAC, providing a possible explanation for the lack of high crack growth observations reported in low alloy steels in structural applications involving low oxygen environments.

Wire, G.L.; Li, Y.Y.

1996-06-01T23:59:59.000Z

358

Coupled heat conduction and thermal stress formulation using explicit integration. [LMFBR  

SciTech Connect (OSTI)

The formulation needed for the conductance of heat by means of explicit integration is presented. The implementation of these expressions into a transient structural code, which is also based on explicit temporal integration, is described. Comparisons of theoretical results with code predictions are given both for one-dimensional and two-dimensional problems. The coupled thermal and structural solution of a concrete crucible, when subjected to a sudden temperature increase, shows the history of cracking. The extent of cracking is compared with experimental data.

Marchertas, A.H.; Kulak, R.F.

1982-06-01T23:59:59.000Z

359

Interacting FisherWright Diffusions in a Catalytic Medium Andreas Greven  

E-Print Network [OSTI]

environment (catalytic medium). Here we introduce a model of interacting Fisher­Wright diffusions where environment, catalytic medium, longtime behaviour, rescaling. AMS Subject Classification: 60K35, 60J70Interacting Fisher­Wright Diffusions in a Catalytic Medium Andreas Greven Mathematisches Institut

Klenke, Achim

360

Industrial Gas Turbine Engine Catalytic Pilot Combustor-Prototype Testing  

SciTech Connect (OSTI)

PCI has developed and demonstrated its Rich Catalytic Lean-burn (RCL®) technology for industrial and utility gas turbines to meet DOEâ??s goals of low single digit emissions. The technology offers stable combustion with extended turndown allowing ultra-low emissions without the cost of exhaust after-treatment and further increasing overall efficiency (avoidance of after-treatment losses). The objective of the work was to develop and demonstrate emission benefits of the catalytic technology to meet strict emissions regulations. Two different applications of the RCL® concept were demonstrated: RCL® catalytic pilot and Full RCL®. The RCL® catalytic pilot was designed to replace the existing pilot (a typical source of high NOx production) in the existing Dry Low NOx (DLN) injector, providing benefit of catalytic combustion while minimizing engine modification. This report discusses the development and single injector and engine testing of a set of T70 injectors equipped with RCL® pilots for natural gas applications. The overall (catalytic pilot plus main injector) program NOx target of less than 5 ppm (corrected to 15% oxygen) was achieved in the T70 engine for the complete set of conditions with engine CO emissions less than 10 ppm. Combustor acoustics were low (at or below 0.1 psi RMS) during testing. The RCL® catalytic pilot supported engine startup and shutdown process without major modification of existing engine controls. During high pressure testing, the catalytic pilot showed no incidence of flashback or autoignition while operating over a wide range of flame temperatures. In applications where lower NOx production is required (i.e. less than 3 ppm), in parallel, a Full RCL® combustor was developed that replaces the existing DLN injector providing potential for maximum emissions reduction. This concept was tested at industrial gas turbine conditions in a Solar Turbines, Incorporated high-pressure (17 atm.) combustion rig and in a modified Solar Turbines, Incorporated Saturn engine rig. High pressure single-injector rig and modified engine rig tests demonstrated NOx less than 2 ppm and CO less than 10 ppm over a wide flame temperature operating regime with low combustion noise (<0.15% peak-to-peak). Minimum NOx for the optimized engine retrofit Full RCL® designs was less than 1 ppm with CO emissions less than 10 ppm. Durability testing of the substrate and catalyst material was successfully demonstrated at pressure and temperature showing long term stable performance of the catalytic reactor element. Stable performance of the reactor element was achieved when subjected to durability tests (>5000 hours) at simulated engine conditions (P=15 atm, Tin=400C/750F.). Cyclic tests simulating engine trips was also demonstrated for catalyst reliability. In addition to catalyst tests, substrate oxidation testing was also performed for downselected substrate candidates for over 25,000 hours. At the end of the program, an RCL® catalytic pilot system has been developed and demonstrated to produce NOx emissions of less than 3 ppm (corrected to 15% O2) for 100% and 50% load operation in a production engine operating on natural gas. In addition, a Full RCL® combustor has been designed and demonstrated less than 2 ppm NOx (with potential to achieve 1 ppm) in single injector and modified engine testing. The catalyst/substrate combination has been shown to be stable up to 5500 hrs in simulated engine conditions.

Shahrokh Etemad; Benjamin Baird; Sandeep Alavandi; William Pfefferle

2009-09-30T23:59:59.000Z

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361

Catalytic membrane program novation: High temperature catalytic membrane reactors. Final report  

SciTech Connect (OSTI)

The original objective was to develop an energy-efficient hydrocarbon dehydrogenation process based on catalytic membrane reactors. Golden Technologies determined that the goals of this contract would be best served by novating the contract to an end user or other interested party which is better informed on the economic justification aspects of petrochemical refining processes to carry out the remaining work. In light of the Chevron results, the program objective was broadened to include development of inorganic membranes for applications in the chemical industry. The proposed membrane technologies shall offer the potential to improve chemical production processes via conversion increase and energy savings. The objective of this subcontract is to seek a party that would serve as a prime contractor to carry out the remaining tasks on the agreement and bring the agreement to a successful conclusion. Four tasks were defined to select the prime contractor. They were (1) prepare a request for proposal, (2) solicit companies as potential prime contractors as well as team members, (3) discuss modifications requested by the potential prime contractors, and (4) obtain, review and rank the proposals. The accomplishments on the tasks is described in detail in the following sections.

Kleiner, R.N. [Kleiner (Richard N.), Englewood, CO (United States)] [Kleiner (Richard N.), Englewood, CO (United States)

1998-08-28T23:59:59.000Z

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

Thermal conductivity of thermal-battery insulations  

SciTech Connect (OSTI)

The thermal conductivities of a variety of insulating materials used in thermal batteries were measured in atmospheres of argon and helium using several techniques. (Helium was used to simulate the hydrogen atmosphere that results when a Li(Si)/FeS{sub 2} thermal battery ages.) The guarded-hot-plate method was used with the Min-K insulation because of its extremely low thermal conductivity. For comparison purposes, the thermal conductivity of the Min-K insulating board was also measured using the hot-probe method. The thermal-comparator method was used for the rigid Fiberfrax board and Fiberfrax paper. The thermal conductivity of the paper was measured under several levels of compression to simulate the conditions of the insulating wrap used on the stack in a thermal battery. The results of preliminary thermal-characterization tests with several silica aerogel materials are also presented.

Guidotti, R.A.; Moss, M.

1995-08-01T23:59:59.000Z

364

SAES ST 909 PILOT SCALE METHANE CRACKING TESTS  

SciTech Connect (OSTI)

Pilot scale (500 gram) SAES St 909 methane cracking tests were conducted to determine material performance for tritium process applications. Tests that ran up to 1400 hours have been performed at 700 C, 202.7 kPa (1520 torr) with a 30 sccm feed of methane, with various impurities, in a 20 vol% hydrogen, balance helium, stream. A 2.5 vol% methane feed was reduced below 30 ppm for 631 hours. A feed of 1.1 vol% methane plus 1.4 vol% carbon dioxide was reduced below 30 ppm for 513 hours. The amount of carbon dioxide gettered by St 909 can be equated to an equivalent amount of methane gettered to estimate a reduced bed life for methane cracking. The effect of 0.4 vol % and 2.1 vol% nitrogen in the feed reduced the time to exceed 30 ppm methane to 362 and 45 hours, respectively, but the nitrogen equivalence to reduced methane gettering capacity was found to be dependent on the nitrogen feed composition. Decreased hydrogen concentrations increased methane getter rates while a drop of 30 C in one bed zone increased methane emissions by over a factor of 30. The impact of gettered nitrogen can be somewhat minimized if the nitrogen feed to the bed has been stopped and sufficient time given to recover the methane cracking rate.

Klein, J; Henry Sessions, H

2007-07-02T23:59:59.000Z

365

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

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

Final Report, "Molecular Design of Hydrocarbon Oxidation Catalytic Processes"  

SciTech Connect (OSTI)

The main goal of this project had been to use model systems to correlate selectivities in partial oxidation catalysis with the presence of specific sites on the surface of the catalyst. Extensive work was performed this year on characterizing oxygen-treated nickel surfaces by chemical means. Specifically, the surface chemistry of ammonia coadsorbed with atomic oxygen on Ni(110) single-crystal surfaces was studied by temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). It was determined that at intermediate oxygen coverages direct ammonia adsorption on nickel sites is suppressed, but a new high-temperature reaction regime is generated at 400 K where NHx surface fragments are rehydrogenated concurrently with the production of water and molecular hydrogen. The extensive isotope scrambling and hydrogen transfer seen from nitrogen- to oxygen-containing surface intermediates, and the optimum yields seen for this 400 K state at intermediate oxygen coverages, strongly suggest the direct interaction of the adsorbed ammonia with oxygen atoms at the end of the –Ni–O- rows that form upon reconstruction of the surface. Hydrogen transfer between ammonia and oxygen appears to take place directly via hydrogen bonding, and to be reversible but biased towards water formation. An equilibrium is reached between the produced water and the reacting surface oxygen and hydrogen. The strong influence of the OH surface groups on the thermal chemistry of the adsorbed ammonia was interpreted in terms of the adsorbing geometry of the OH groups on the surface, and of hydrogen bonding between adsorbed OH and NH3 species. In terms of alcohol reactivity, the adsorption of 2-iodoethanol, a precursor for the preparation of 2-hydroxyethyl and oxametallacycle surface species, was found to lead to two configurations involving either just the iodine atom or both iodine and hydroxyl ends of the molecule. A complex chemical behavior starts around 140 K with the production of small amounts of ethylene and water, most likely via the concerted decomposition or disproportionation of the adsorbed molecular species. The bulk of the 2-iodoethanol decomposes at about 150 K via an initial carbon-iodine scission to form –O(H)CH2CH2– (~80%) and 2-hydroxyethyl (~20%) intermediates. Two competing reactions are involved with the subsequent conversion of the 2-hydroxyethyl species around 160 K, a reductive elimination with surface hydrogen to yield ethanol, and a ?-H elimination to surface vinyl alcohol. The –O(H)CH2CH2–, on the other hand, dehydrogenates to a –OCH2CH2– oxametallacycle species about the same temperature. Both 2-hydroxyethyl and oxametallacycle species tautomerize to acetaldehyde, around 210 K and above 250 K, respectively, and some of that acetaldehyde desorbs while the rest decomposes to hydrogen and carbon monoxide. We contend that a better understanding of the surface chemistry of oxygen-containing surfaces can lead to better selectivities in catalysis. This is arguably the most important issue in the field of catalysis in the near future, and one that impacts several technologies of interest to DOE such as the manufacturing of speciality chemicals and the control and removal of pollutants. Additional work was performed on the characterization of the chemistry of methyl and methylene adsorbed species on oxygen-treated nickel surfaces. Complex chemistry was observed involving not only hydrogenation and dehydrogenation steps, but also C-C couplings and methylene insertions to produce heavier hydrocarbons, and oxygen insertion reactions that yield oxygenates. Finally, a dual titration technique employing xenon and a chemically sensitive probe was developed to identify minority catalytic sites on oxide surfaces. In the case of oxygen-treated Ni(110) single crystals, it was found that both hydrogen transfer with adsorbed water or ammonia and certain hydrocarbon hydrogenation reactions take place at the end of the –Ni–O rows that form in this system. Carbon and nitrogen oxides, on the other hand, display no pre

Professor Francisco Zaera

2007-08-09T23:59:59.000Z

368

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

369

Microstructural and solidification cracking evaluation of electron beam welds in 304L  

SciTech Connect (OSTI)

Weld hot cracking of stainless steels is a major materials-related problem in the welding industry. This present investigation evaluates the crack susceptibility of highly-constrained EB welds made in materials whose DeLong ferrite potentials range from zero to nine FN. In addition, the effect of piece part strength level on cracking is examined. This study has revealed that these deep penetration EB welds have regions that solidify as primary austenite, even when the DeLong ferrite potential is as high as 9 FN. This points out the critical role that solidification rate plays in the crack susceptibility of these highly restrained welds. In addition, 0 FN to 0 FN welds had primarily transverse cracks while 6 FN to 0 FN welds had primarily centerline cracks. Of particular interest is the observation that cracks still occur if a high ferrite (greater than 6 FN) component is welded to a zero FN component. Cracking is always associated with regions which solidify as primary austenite and these cracks occur because there are areas in the weld which do not mix. Thus it is not a recommended production practice to compensate for low ferrite in one piece part with high ferrite in its mate. Finally, it is shown that a DeLong FN threshold of 4 to prevent cracking in EB welds in not valid. 21 refs., 16 figs.

Sturgill, P.L.; Campbell, R.D.; Henningsen, J.L.

1991-01-01T23:59:59.000Z

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

Fatigue Crack Propagation from Notched Specimens of 304 SS in elevated Temperature Aqueous Environment  

SciTech Connect (OSTI)

Fatigue crack propagation (FCP) rates for 304 stainless steel (304SS) were determined in 24 degree C and 288 degree C air and 288 degree C water using double-edged notch (DEN) specimens of 304 stainless steel (304 SS). Test performed at matched loading conditions in air and water at 288 degree C with 20-6- cc h[sub]2/kg h[sub]2O provided a direct comparison of the relative crack growth rates in air and water over a wide range of crack growth rates. The DEN crack extension ranged from short cracks (0.03-0.25 mm) to long cracks up to 4.06 mm, which are consistent with conventional deep crack tests. Crack growth rates of 304 SS in water were about 12 times the air rate. This 12X environmental enhancement persisted to crack extensions up to 4.06 mm, far outside the range associated with short crack effects. The large environmental degradation for 304 SS crack growth is consistent with the strong reduction of fatigue life in high hydrogen water. Further, very similar environmental effects w ere reported in fatigue crack growth tests in hydrogen water chemistry (HWC). Most literature data in high hydrogen water show only a mild environmental effect for 304 SS, of order 2.5 times air or less, but the tests were predominantly performed at high cyclic stress intensity or equivalently, high air rates. The environmental effect in low oxygen environments at low stress intensity depends strongly on both the stress ratio, R, and the load rise time, T[sub]r, as recently reported for austenitic stainless steel in BWR water. Fractography was performed for both tests in air and water. At 288 degree C in water, the fracture surfaces were crisply faceted with a crystallographic appearance, and showed striations under high magnification. The cleavage-like facets on the fracture surfaces suggest that hydrogen embrittlement is the primary cause of accelerated cracking.

Wire, G. L.; Mills, W. J.

2002-08-01T23:59:59.000Z

372

Method for recovering catalytic elements from fuel cell membrane electrode assemblies  

DOE Patents [OSTI]

A method for recovering catalytic elements from a fuel cell membrane electrode assembly is provided. The method includes converting the membrane electrode assembly into a particulate material, wetting the particulate material, forming a slurry comprising the wetted particulate material and an acid leachate adapted to dissolve at least one of the catalytic elements into a soluble catalytic element salt, separating the slurry into a depleted particulate material and a supernatant containing the catalytic element salt, and washing the depleted particulate material to remove any catalytic element salt retained within pores in the depleted particulate material.

Shore, Lawrence (Edison, NJ); Matlin, Ramail (Berkeley Heights, NJ); Heinz, Robert (Ludwigshafen, DE)

2012-06-26T23:59:59.000Z

373

High Temperature Thermal Array for Next Generation Solar Thermal...  

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

High Temperature Thermal Array for Next Generation Solar Thermal Power Production High Temperature Thermal Array for Next Generation Solar Thermal Power Production This...

374

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

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

Subcritical Crack Growth in Ceramic Composites at High Temperature Measured Using Digital Image Correlation  

SciTech Connect (OSTI)

An in situ experimental technique is described that allows high resolution, high sensitivity determination of displacements and full-field strains during high temperature mechanical testing. The technique is used to investigate elevated temperature crack growth in SiC/Nicalon sub f composites. At 1150 degrees C, the reinforcing fibers have a higher creep susceptibility than the matrix. Fiber creep leads to relaxation of crack bridging tractions, resulting in subcritical crack growth. Differential image analysis is used to measure the crack opening displacement profile u(x) of an advancing, bridged crack. With appropriate modeling, such data can be used to determine the traction law, from which the mechanics of cracking and failure may be determined.

Mumm, D.R.; Morris, W.L.; Dadkhah, M.S.; Cox, B.N.

1996-01-11T23:59:59.000Z

377

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

378

Catalytic Upgrading of Sugars to Hydrocarbons 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 technology pathway case investigates the catalytic conversion of solubilized carbohydrate streams to hydrocarbon biofuels, utilizing data from recent efforts within the National Advanced Biofuels Consortium (NABC) in collaboration with Virent, Inc.. Technical barriers and key research needs that should be pursued for the catalytic conversion of sugars pathway to be competitive with petroleum-derived gasoline, diesel and jet range hydrocarbon blendstocks have been identified.

Biddy, Mary J.; Jones, Susanne B.

2013-03-31T23:59:59.000Z

379

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

380

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

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

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....

382

Hybrid lean premixing catalytic combustion system for gas turbines  

DOE Patents [OSTI]

A system and method of combusting a hydrocarbon fuel is disclosed. The system combines the accuracy and controllability of an air staging system with the ultra-low emissions achieved by catalytic combustion systems without the need for a pre-heater. The result is a system and method that is mechanically simple and offers ultra-low emissions over a wide range of power levels, fuel properties and ambient operating conditions.

Critchley, Ian L.

2003-12-09T23:59:59.000Z

383

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

384

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

385

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

386

Assessment and prediction of drying shrinkage cracking in bonded mortar overlays  

SciTech Connect (OSTI)

Restrained drying shrinkage cracking was investigated on composite beams consisting of substrate concrete and bonded mortar overlays, and compared to the performance of the same mortars when subjected to the ring test. Stress development and cracking in the composite specimens were analytically modeled and predicted based on the measurement of relevant time-dependent material properties such as drying shrinkage, elastic modulus, tensile relaxation and tensile strength. Overlay cracking in the composite beams could be very well predicted with the analytical model. The ring test provided a useful qualitative comparison of the cracking performance of the mortars. The duration of curing was found to only have a minor influence on crack development. This was ascribed to the fact that prolonged curing has a beneficial effect on tensile strength at the onset of stress development, but is in the same time not beneficial to the values of tensile relaxation and elastic modulus. -- Highlights: •Parameter study on material characteristics influencing overlay cracking. •Analytical model gives good quantitative indication of overlay cracking. •Ring test presents good qualitative indication of overlay cracking. •Curing duration has little effect on overlay cracking.

Beushausen, Hans, E-mail: hans.beushausen@uct.ac.za; Chilwesa, Masuzyo

2013-11-15T23:59:59.000Z

387

Mixed Mode Static and Fatigue Crack Growth in Wind Blade Paste Adhesives  

E-Print Network [OSTI]

, static GIc and mixed mode fracture, and fatigue crack growth resistance. I. Introduction Wind turbine blades are large composite structures which are typically resin infusion molded in sections

388

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

389

Effects of weld residual stresses on crack-opening area analysis of pipes for LBB applications  

SciTech Connect (OSTI)

This paper summarizes four different studies undertaken to evaluate the effects of weld residual stresses on the crack-opening behavior of a circumferential through-wall crack in the center of a girth weld. The effect of weld residual stress on the crack-opening-area and leak-rate analyses of a pipe is not well understood. There are no simple analyses to account for these effects, and, therefore, they are frequently neglected. The four studies involved the following efforts: (1) Full-field thermoplastic finite element residual stress analyses of a crack in the center of a girth weld, (2) A comparison of the crack-opening displacements from a full-field thermoplastic residual stress analysis with a crack-face pressure elastic stress analysis to determine the residual stress effects on the crack-opening displacement, (3) The effects of hydrostatic testing on the residual stresses and the resulting crack-opening displacement, and (4) The effect of residual stresses on crack-opening displacement with different normal operating stresses.

Dong, P.; Rahman, S.; Wilkowski, G. [and others

1997-04-01T23:59:59.000Z

390

E-Print Network 3.0 - alligator cracking Sample Search Results  

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

search results for: alligator cracking Page: << < 1 2 3 4 5 > >> 1 Project Summary Report 7-4975-S PROJECTSUMMARYREPORT CENTER FOR TRANSPORTATION RESEARCH Summary: . For...

391

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

392

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...

393

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

394

Thermal barrier coating resistant to sintering  

DOE Patents [OSTI]

A device (10) is made, having a ceramic thermal barrier coating layer (16) characterized by a microstructure having gaps (18) with a sintering inhibiting material (22) disposed on the columns (20) within the gaps (18). The sintering resistant material (22) is stable over the range of operating temperatures of the device (10), is not soluble with the underlying ceramic layer (16) and is applied by a process that is not an electron beam physical vapor deposition process. The sintering inhibiting material (22) has a morphology adapted to improve the functionality of the sintering inhibiting material (22), characterized as continuous, nodule, rivulet, grain, crack, flake and combinations thereof and being disposed within at least some of the vertical and horizontal gaps.

Subramanian, Ramesh; Seth, Brig B.

2005-08-23T23:59:59.000Z

395

Nonlinear FE analysis of cracks in tension and shear  

E-Print Network [OSTI]

Carbon FRP Shear Reinforcement. PhD thesis, University of Cambridge, UK, 2003. 3. Bazant Z. P. and Planas J. Fracture and Size Effect in Con- crete and Other Quasibrittle Materials. CRC Press, Boca Raton, Florida, 1998. Nonlinear FE analysis of cracks... of plain concrete to cyclic tension. ACI Materials Journal, 1987, 84, No. 5, 365–373. 9. Paulay T. and Loeber P. J. Shear transfer by aggregate inter- lock. ACI Special Publication, SP-42, 1974, 1, 1–14. 10. Houde J. and Mirza M. S. A finite element...

Kesse, G.; Lees, Janet M.

2007-05-01T23:59:59.000Z

396

On the approximation of crack shapes found during inservice inspection  

SciTech Connect (OSTI)

This paper addresses the characterization of axial internal flaw found during inservice inspection of a pipe. J-integral distribution for various flaw shapes is obtained using line spring finite, element method. The peak J-value and its distribution across the crack is found to be characteristic feature of each shape. The triangular shape yields peak J-value away from the center, the point of depth. The elliptic approximation results in large overestimate of J-value for unsymmetric flaws. Triangular approximation is recommended for such flaws so that further service can be obtained from the component.

Bhate, S.R.; Chawla, D.S.; Kushwaha, H.S. [Bhabha Atomic Research Centre, Bombay (India)] [and others

1997-04-01T23:59:59.000Z

397

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

398

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

399

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

400

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

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

Residual stresses and stress corrosion cracking in pipe fittings  

SciTech Connect (OSTI)

Residual stresses can play a key role in the SCC performance of susceptible materials in PWR primary water applications. Residual stresses are stresses stored within the metal that develop during deformation and persist in the absence of external forces or temperature gradients. Sources of residual stresses in pipe fittings include fabrication processes, installation and welding. There are a number of methods to characterize the magnitude and orientation of residual stresses. These include numerical analysis, chemical cracking tests, and measurement (e.g., X-ray diffraction, neutron diffraction, strain gage/hole drilling, strain gage/trepanning, strain gage/section and layer removal, and acoustics). This paper presents 400 C steam SCC test results demonstrating that residual stresses in as-fabricated Alloy 600 pipe fittings are sufficient to induce SCC. Residual stresses present in as-fabricated pipe fittings are characterized by chemical cracking tests (stainless steel fittings tested in boiling magnesium chloride solution) and by the sectioning and layer removal (SLR) technique.

Parrington, R.J.; Scott, J.J.; Torres, F.

1994-06-01T23:59:59.000Z

402

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

403

Low-Cracking High-Performance Concrete (LC-HPC) Bridge Decks: Shrinkage-Reducing Admixtures, Internal Curing, and Cracking Performance  

E-Print Network [OSTI]

ABSTRACT The development, construction, and evaluation of low-cracking high-performance concrete (LC-HPC) bridge decks is described based on laboratory tests of mixtures containing shrinkage-reducing admixtures and mineral admixtures in conjunction...

Pendergrass, Ben Andrew

2014-05-31T23:59:59.000Z

404

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

405

Pattern of Thermal Fluctuations in a Recovery Boiler Floor  

SciTech Connect (OSTI)

The floor of a black liquor recovey boiler at a mill in central Canada has experienced cracking and delamination of the composite tubing near the spout wall and deformation of the floor panels that is most severe in the vicinity of the spout wall. One possible explanation for the observed damage is impacts of salt cake falling from the convective section onto the floor. In order to determine if such impacts do occur, strain gauges and thermocouples were installed on the boiler floor in areas where cracking and deformation were most frequent. The data obtained from these instruments indicate that brief, sudden temperature fluctuations do occur, and changes in the strain experienced by the affected tube occur simultaneously. These fluctuations appear to occur less often along the spout wall and more frequently with increasing distance from the wall. The frequency of these temperature fluctuations is insufficient for thermal fatigue to be the sole cause of the cracking observed on the tubes, but the data are consistent with what might be expected from pieces of falling salt cake.

Abdullah, Z.; Gorog, J.P.; Keiser, J.R.; Meyers, L.E.; Swindeman, R.W.

1999-04-25T23:59:59.000Z

406

Pattern of thermal fluctuations in a recovery boiler floor  

SciTech Connect (OSTI)

The floor of a black liquor recovery boiler at a mill in central Canada has experienced cracking and delamination of the composite tubing near the spout wall and deformation of the floor panels that is most severe in the vicinity of the spout wail. One possible explanation for the observed damage is impacts of salt cake falling from the convective section onto the floor. In order to determine if such impacts do occur, strain gauges and thermocouples were installed on the boiler floor in areas where cracking and deformation were most frequent. The data obtained from these instruments indicate that brief, sudden temperature fluctuations do occur, and changes in the strain experienced by-the affected tube occur simultaneously. These fluctuations appear to occur less often along the spout wall and more frequently with increasing distance from the wall. The frequency of these temperature fluctuations is insufficient for thermal fatigue to be the sole cause of the cracking observed on the tubes, but the data are consistent with what might be expected from pieces of falling salt cake.

Keiser, J.R.; Meyers, L.E.; Swindeman, R.W.; Gorog, J.P.; Abdullah, Z.

1999-07-01T23:59:59.000Z

407

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

408

Thermo-optical modulation for improved ultrasonic fatigue crack detection in Ti6Al4V  

E-Print Network [OSTI]

scatterers, such as surface grooves, corrosion pits, coarse grains, etc. that might hide the fatigue crack to grow at unexpectedly high growth rates well below the large-crack threshold in aluminum, aluminum­lithium) and secondary irregulari- ties (e.g. uneven machining, mechanical wear, corrosion, etc.). Second

Nagy, Peter B.

409

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

410

Ultrasonic ply-by-ply detection of matrix cracks in laminated composites  

E-Print Network [OSTI]

on the internal damage state of the composite tank wall. Damage in the form of matrix cracks in the composite material of the tank is responsible for the through-the-thickness permeation of LH2. In this context, the detection of matrix cracks takes...

Ganpatye, Atul Shridatta

2005-02-17T23:59:59.000Z

411

Effect of Blast Design on Crack Response C.H. Dowding  

E-Print Network [OSTI]

Effect of Blast Design on Crack Response C.H. Dowding Professor of Civil & Environmental to assess the effect of changes in blast design on the house response. Velocity response was measured some 11 velocity transducers and 3 crack sensors measured excitation and response for each blast

412

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

413

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

414

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

415

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

416

ccsd-00095604,version1-18Sep2006 Understanding crack versus cavitation in pressure-sensitive  

E-Print Network [OSTI]

ccsd-00095604,version1-18Sep2006 Understanding crack versus cavitation in pressure show that in addition to cavitation, interfacial cracks are encountered in a probe-tack traction test mechanisms in usual adhesives. The most common one is cavitation, as evidenced by the first tests

Paris-Sud XI, Université de

417

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

418

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

419

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

420

Analysis of the tube-sheet cracking in slurry oil steam , L.J. Qiao a,  

E-Print Network [OSTI]

Analysis of the tube-sheet cracking in slurry oil steam generators L.K. Zhu a , L.J. Qiao a, , X and increased costs. In this study, the mechanisms of the tube- sheet cracking in slurry oil steam generators steam generator is a kind of shell and tube heat exchanger extensively used in the oil refinement

Volinsky, Alex A.

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

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

422

New sub-family of lysozyme-like proteins shows no catalytic activity...  

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

modest sequence similarity to phage-like lysozyme (N-acetylmuramidase) but appears to lack essential catalytic residues that are strictly conserved in all lysozymes. Close...

423

E-Print Network 3.0 - auto-catalytic electroless plating Sample...  

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

electroless plating Page: << < 1 2 3 4 5 > >> 1 Preparation of highly dispersed PEM fuel cell catalysts using electroless deposition methods Summary: (ED). ED is a catalytic...

424

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

425

Efficient solution of multiple cracks in great number using eigen COD boundary integral equations with iteration procedure  

E-Print Network [OSTI]

as the fibre-reinforced brittle materials after certain extent of tensile damage. The prediction of crack in an infinite domain under fictitious traction acting on the crack surface. With the concept of eigen COD

Liu, Yijun

426

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

427

Reflective Cracking Study: First-level Report on HVS Testing on Section 586RF - 45 mm MB15-GOverlay  

E-Print Network [OSTI]

of the asphalt concrete layer. Testing was stopped when thetesting being performed to validate Caltrans overlay strategies for the rehabilitation of cracked asphalt concrete.concrete. It describes the results of the fifth HVS reflective cracking testing

Jones, David; Wu, R; Harvey, John T

2008-01-01T23:59:59.000Z

428

Reflective Cracking Study: First-Level Report on HVS Testing on Section 589RF - 45 mm MB4-G Overlay  

E-Print Network [OSTI]

of the asphalt concrete layer. Testing was stopped when thetesting being performed to validate Caltrans overlay strategies for the rehabilitation of cracked asphalt concrete.concrete. It describes the results of the second HVS reflective cracking testing

Jones, David; Harvey, John T; Wu, R; Lea, J.

2008-01-01T23:59:59.000Z

429

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

430

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

431

Vickers microindentation toughness of a sintered SiC in the median-crack regime  

SciTech Connect (OSTI)

The Vickers microindentation method for the determination of the fracture toughness of ceramics was investigated in the median crack regime for a sintered alpha SiC. The results are compared with fracture toughness measurements by conventional fracture mechanics technique and also with the reported indentation toughness for the low-load Palmqvist crack regime. Indentation toughnesses in the median crack regime vary widely depending on the choice of the specific equation which is applied. The indentation toughnesses are also load (crack length) dependent. A decreasing R-curve trend results, in contradiction to the flat R-curve that has been observed with conventional fracture mechanics techniques. It is concluded that the Vickers microindentation method is not a reliable technique for the determination of the fracture toughness of ceramics in the median crack regime.

Ghosh, Asish; Kobayashi, A.S. (Washington Univ., Seattle, WA (United States). Coll. of Engineering); Li, Zhuang (Argonne National Lab., IL (United States)); Henager, C.H. Jr. (Pacific Northwest Lab., Richland, WA (United States)); Bradt, R.C. (Nevada Univ., Reno, NV (United States). Mackay School of Mines)

1991-01-01T23:59:59.000Z

432

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

433

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

434

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

435

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

436

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

437

EFFECT OF STRESS GRADIENT AT THE VICINITY OF A CRACK TIP ON IONIC DIFFUSION IN SILICATE GLASSES: AN AFM STUDY.  

E-Print Network [OSTI]

1 EFFECT OF STRESS GRADIENT AT THE VICINITY OF A CRACK TIP ON IONIC DIFFUSION IN SILICATE GLASSES.marliere@univ-montp2.fr ABSTRACT The slow advance of a crack in sodo-silicate glasses was studied at nanometer scale-micrometric vicinity of the tip of a crack running in silicate glass with mobile ions (as sodium cations) and check

Demouchy, Sylvie

438

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

439

Non-thermal Plasma Chemistry Non-thermal Thermal  

E-Print Network [OSTI]

-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;Leuchtstoffröhre Plasma-Bildschirm Energiesparlampe #12;electrical engineering light sources textile industry

Greifswald, Ernst-Moritz-Arndt-Universität

440

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

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

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

442

Studies Relevent to Catalytic Activation Co & other small Molecules  

SciTech Connect (OSTI)

Detailed annual and triannual reports describing the progress accomplished during the tenure of this grant were filed with the Program Manager for Catalysis at the Office of Basic Energy Sciences. To avoid unnecessary duplication, the present report will provide a brief overview of the research areas that were sponsored by this grant and list the resulting publications and theses based on this DOE supported research. The scientific personnel participating in (and trained by) this grant's research are also listed. Research carried out under this DOE grant was largely concerned with the mechanisms of the homogeneous catalytic and photocatalytic activation of small molecules such as carbon monoxide, dihydrogen and various hydrocarbons. Much of the more recent effort has focused on the dynamics and mechanisms of reactions relevant to substrate carbonylations by homogeneous organometallic catalysts. A wide range of modern investigative techniques were employed, including quantitative fast reaction methodologies such as time-resolved optical (TRO) and time-resolved infrared (TRIR) spectroscopy and stopped flow kinetics. Although somewhat diverse, this research falls within the scope of the long-term objective of applying quantitative techniques to elucidate the dynamics and understand the principles of mechanisms relevant to the selective and efficient catalytic conversions of fundamental feedstocks to higher value materials.

Ford, Peter C

2005-02-22T23:59:59.000Z

443

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

444

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

445

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

446

Thermal Processes | Department of Energy  

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

Hydrogen Production Current Technology Thermal Processes Thermal Processes Some thermal processes use the energy in various resources, such as natural gas, coal, or biomass,...

447

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

448

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

449

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

450

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

451

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

452

Conditions under which cracks occur in modified 13% chromium steel in wet hydrogen sulfide environments  

SciTech Connect (OSTI)

Occurrence of cracks in an API 13% Cr steel, modified 13% Cr steel, and duplex stainless steel were compared in various wet, mild hydrogen sulfide (H{sub 2}S) environments. The conditions under which cracks occurred in the modified 13% Cr steel in oil and gas production environments were made clear. No cracks occurred if pH > depassivation pH (pH{sub d}) and redox potential of sulfur (E{sub S(red/ax)}) < pitting potential (V{sub c}). Hydrogen embrittlement-type cracks occurred in pH > Ph{sub d} and E{sub S(red/ax)} > V{sub c}. The pH inside the pit decreased drastically and hydrogen embrittlement occurred. Cracks of the hydrogen embrittlement type occurred if pH < pH{sub d} and threshold hydrogen concentration under which cracks occur (H{sub th}) < hydrogen concentration in steel (H{sub 0}). No cracks occurred if pH < pH{sub d} and H{sub th} > H{sub 0}.

Hara, T.; Asahi, H.

2000-05-01T23:59:59.000Z

453

Fracture analysis of axially cracked pressure tube of pressurized heavy water reactor  

SciTech Connect (OSTI)

Three Dimensional (313) finite element elastic plastic fracture analysis was done for through wall axially cracked thin pressure tubes of 220 MWe Indian Pressurized Heavy Water Reactor. The analysis was done for Zr-2 and Zr-2.5Nb pressure tubes operating at 300{degrees}C and subjected to 9.5 Mpa internal pressure. Critical crack length was determined based on tearing instability concept. The analysis included the effect of crack face pressure due to the leaking fluid from tube. This effect was found to be significant for pressure tubes. The available formulae for calculating J (for axially cracked tubes) do not take into account the effect of crack face pressure. 3D finite element analysis also gives insight into variation of J across the thickness of pressure tube. It was observed that J is highest at the mid-surface of tube. The results have been presented in the form of across the thickness average J value and a peak factor on J. Peak factor on J is ratio of J at mid surface to average J value. Crack opening area for different cracked lengths was calculated from finite element results. The fracture assessment of pressure tubes was also done using Central Electricity Generating Board R-6 method. Ductile tearing was considered.

Krishnan, S.; Bhasin, V.; Mahajan, S.C. [Bhabha Atomic Research Centre, Bombay (India)] [and others

1997-04-01T23:59:59.000Z

454

Threshold velocity for environmentally-assisted cracking in low alloy steels  

SciTech Connect (OSTI)

Environmentally Assisted Cracking (EAC) in low alloy steels is generally believed to be activated by dissolution of MnS inclusions at the crack tip in high temperature LWR environments. EAC is the increase of fatigue crack growth rate of up to 40 to 100 times the rate in air that occurs in high temperature LWR environments. A steady state theory developed by Combrade, suggested that EAC will initiate only above a critical crack velocity and cease below this same velocity. A range of about twenty in critical crack tip velocities was invoked by Combrade, et al., to describe data available at that time. This range was attributed to exposure of additional sulfides above and below the crack plane. However, direct measurements of exposed sulfide densities on cracked specimens were performed herein and the results rule out significant additional sulfide exposure as a plausible explanation. Alternatively, it is proposed herein that localized EAC starting at large sulfide clusters reduces the calculated threshold velocity from the value predicted for a uniform distribution of sulfides. Calculations are compared with experimental results where the threshold velocity has been measured, and the predicted wide range of threshold values for steels of similar sulfur content but varying sulfide morphology is observed. The threshold velocity decreases with the increasing maximum sulfide particle size, qualitatively consistent with the theory. The calculation provides a basis for a conservative minimum velocity threshold tied directly to the steel sulfur level, in cases where no details of sulfide distribution are known.

Wire, G.L.; Kandra, J.T.

1997-04-01T23:59:59.000Z

455

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

456

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

457

Burning Velocities in Catalytically Assisted Self-Propagating High-Temperature Combustion Synthesis Systems  

E-Print Network [OSTI]

Burning Velocities in Catalytically Assisted Self-Propagating High-Temperature Combustion Synthesis of catalytically assisted self-propagating high-temperature synthesis (SHS) of the tantalum/carbon material system. © 2001 by The Combustion Institute INTRODUCTION Self-propagating high-temperature combustion synthesis

Wooldridge, Margaret S.

458

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

459

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

E-Print Network [OSTI]

Micro Catalytic Combustor with Pd/Nano-porous Alumina for High-Temperature Application Takashi: A micro-scale catalytic combustor using high-precision ceramic tape-casting technology has been developed surface reaction of butane. In combustion experiments with a prototype combustor, the wall temperature

Kasagi, Nobuhide

460

Non-uniform Heat Generation in Micro Catalytic Combustor Takashi Okamasa*, Yuji Suzuki, and Nobuhide Kasagi  

E-Print Network [OSTI]

Non-uniform Heat Generation in Micro Catalytic Combustor Takashi Okamasa*, Yuji Suzuki@thtlab.t.u-tokyo.ac.jp Abstract We developed a micro catalytic combustor using high-precision ceramic tape-casting technology and nano-porous alumina catalyst layer. It is found that failure of the ceramic combustor occurs due

Kasagi, Nobuhide

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

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...

462

MEMS-based fuel cells with integrated catalytic fuel processor and method thereof  

DOE Patents [OSTI]

Described herein is a means to incorporate catalytic materials into the fuel flow field structures of MEMS-based fuel cells, which enable catalytic reforming of a hydrocarbon based fuel, such as methane, methanol, or butane. Methods of fabrication are also disclosed.

Jankowski, Alan F. (Livermore, CA); Morse, Jeffrey D. (Martinez, CA); Upadhye, Ravindra S. (Pleasanton, CA); Havstad, Mark A. (Davis, CA)

2011-08-09T23:59:59.000Z

463

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

464

Crack growth rates of nickel alloy welds in a PWR environment.  

SciTech Connect (OSTI)

In light water reactors (LWRs), vessel internal components made of nickel-base alloys are susceptible to environmentally assisted cracking. A better understanding of the causes and mechanisms of this cracking may permit less conservative estimates of damage accumulation and requirements on inspection intervals. A program is being conducted at Argonne National Laboratory to evaluate the resistance of Ni alloys and their welds to environmentally assisted cracking in simulated LWR coolant environments. This report presents crack growth rate (CGR) results for Alloy 182 shielded-metal-arc weld metal in a simulated pressurized water reactor (PWR) environment at 320 C. Crack growth tests were conducted on 1-T compact tension specimens with different weld orientations from both double-J and deep-groove welds. The results indicate little or no environmental enhancement of fatigue CGRs of Alloy 182 weld metal in the PWR environment. The CGRs of Alloy 182 in the PWR environment are a factor of {approx}5 higher than those of Alloy 600 in air under the same loading conditions. The stress corrosion cracking for the Alloy 182 weld is close to the average behavior of Alloy 600 in the PWR environment. The weld orientation was found to have a profound effect on the magnitude of crack growth: cracking was found to propagate faster along the dendrites than across them. The existing CGR data for Ni-alloy weld metals have been compiled and evaluated to establish the effects of key material, loading, and environmental parameters on CGRs in PWR environments. The results from the present study are compared with the existing CGR data for Ni-alloy welds to determine the relative susceptibility of the specific Ni-alloy weld to environmentally enhanced cracking.

Alexandreanu, B.; Chopra, O. K.; Shack, W. J.; Energy Technology

2006-05-31T23:59:59.000Z

465

Simulations of Failure via Three-Dimensional Cracking in Fuel Cladding for Advanced Nuclear Fuels  

SciTech Connect (OSTI)

Enhancing performance of fuel cladding and duct alloys is a key means of increasing fuel burnup. This project will address the failure of fuel cladding via three-dimensional cracking models. Researchers will develop a simulation code for the failure of the fuel cladding and validate the code through experiments. The objective is to develop an algorithm to determine the failure of fuel cladding in the form of three-dimensional cracking due to prolonged exposure under varying conditions of pressure, temperature, chemical environment, and irradiation. This project encompasses the following tasks: 1. Simulate 3D crack initiation and growth under instantaneous and/or fatigue loads using a new variant of the material point method (MPM); 2. Simulate debonding of the materials in the crack path using cohesive elements, considering normal and shear traction separation laws; 3. Determine the crack propagation path, considering damage of the materials incorporated in the cohesive elements to allow the energy release rate to be minimized; 4. Simulate the three-dimensional fatigue crack growth as a function of loading histories; 5. Verify the simulation code by comparing results to theoretical and numerical studies available in the literature; 6. Conduct experiments to observe the crack path and surface profile in unused fuel cladding and validate against simulation results; and 7. Expand the adaptive mesh refinement infrastructure parallel processing environment to allow adaptive mesh refinement at the 3D crack fronts and adaptive mesh merging in the wake of cracks. Fuel cladding is made of materials such as stainless steels and ferritic steels with added alloying elements, which increase stability and durability under irradiation. As fuel cladding is subjected to water, chemicals, fission gas, pressure, high temperatures, and irradiation while in service, understanding performance is essential. In the fast fuel used in advanced burner reactors, simulations of the nuclear fuels are critical to understand the burnup, and thus the fuel efficiency.

Lu, Hongbing; Bukkapatnam, Satish; Harimkar, Sandip; Singh, Raman; Bardenhagen, Scott

2014-01-09T23:59:59.000Z

466

Coupled Thermal-Hydrological-Mechanical-Chemical Model And Experiments...  

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

of mechanistic crack growth and grain contact models for chemically induced subcritical crack growth and pressure solution, with porosity-permeability changes * Conduct...

467

Coupled Thermal-Hydrological-Mechanical-Chemical Model and Experiments...  

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

of mechanistic crack growth and grain contact models for chemically induced subcritical crack growth and pressure solution, with porosity-permeability changes * Conduct...

468

The stress field around two parallel edge cracks in a finite body  

E-Print Network [OSTI]

the application of the Schwarz alternating method in conjunction with complex mapping techniques for modelling the stress fields around two arbitrarily oriented cracks in an infinite body (see Fig. 1. 4). M P 0. 83W I. 83W Again 19. Isolated, Single...-Ended Crack Located in a Finite Body. " Zo r A I I 0 I Figure IA. Two Aibitnuily Oiiented Conchs Located in an Infinite Body. t CHAFIXR II FULL-FIELD REPRESENTATION OF THE STRESS FIELD SURROUNDING TWO EDGE CRACKS OVERVIEW OF THE METHODOLOGY USED...

Hardin, Patrick Wayne

2012-06-07T23:59:59.000Z

469

A numerical study of crack initiation in a bcc iron system based on dynamic bifurcation theory  

SciTech Connect (OSTI)

Crack initiation under dynamic loading conditions is studied under the framework of dynamic bifurcation theory. An atomistic model for BCC iron is considered to explicitly take into account the detailed molecular interactions. To understand the strain-rate dependence of the crack initiation process, we first obtain the bifurcation diagram from a computational procedure using continuation methods. The stability transition associated with a crack initiation, as well as the connection to the bifurcation diagram, is studied by comparing direct numerical results to the dynamic bifurcation theory [R. Haberman, SIAM J. Appl. Math. 37, 69–106 (1979)].

Li, Xiantao, E-mail: xli@math.psu.edu [Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

2014-10-28T23:59:59.000Z

470

Response Surfaces for optimal weight of cracked composite panels: noise and accuracy  

E-Print Network [OSTI]

Two levels of fidelity are used for minimum weight design of a composite blade-stiffened panel subject to crack propagation constraints. The low fidelity approach makes use of an equivalent strain constraint calculated by a closed form solution for the stress intensity factor. The high fidelity approach uses the stress intensity factor directly as the constraint and computes it from the stress distribution around the crack. A number of panels were optimized by both approaches for different values of applied load, crack length, and blade height, and response surface approximations for optimal weight as function of these configuration variables were constructed. Computational cost, noise and accuracy for the results are compared.

Melih Papila; Raphael T. Haftka

471

Petroleum Refinery Catalytic Reforming -- Cutting High Energy Costs  

E-Print Network [OSTI]

. It is essential that the operation and maintenance of these furnaces be optimized to minimize production costs. This paper describes the performance testing and evaluation of a set of ten refinery furnaces used to thermally drive several reforming reactors...

Viar, W. L.

1979-01-01T23:59:59.000Z

472

Biofuels from Corn Stover: Pyrolytic Production and Catalytic Upgrading Studies  

E-Print Network [OSTI]

Due to security issues in energy supply and environmental concerns, renewable energy production from biomass becomes an increasingly important area of study. Thus, thermal conversion of biomass via pyrolysis and subsequent upgrading procedures were...

Capunitan, Jewel Alviar

2013-01-15T23:59:59.000Z

473

Porous Core-Shell Nanostructures for Catalytic Applications  

E-Print Network [OSTI]

Titanium Incorporation within Silica Shell . 7.3 Pyridine5 Oxidative Growth of ZnO for Core-Shell Catalysis 5.13.3.2 Shell interaction dependent catalysis 3.3.3 Thermal

Ewers, Trevor David

2012-01-01T23:59:59.000Z

474

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

475

Producing Clean Syngas via Catalytic Reforming for Fuels Production  

SciTech Connect (OSTI)

Thermochemical biomass conversion to fuels and chemicals can be achieved through gasification to syngas. The biomass derived raw syngas contains the building blocks of carbon monoxide and hydrogen as well as impurities such as tars, light hydrocarbons, and hydrogen sulfide. These impurities must be removed prior to fuel synthesis. We used catalytic reforming to convert tars and hydrocarbons to additional syngas, which increases biomass carbon utilization. In this work, nickel based, fluidizable tar reforming catalysts were synthesized and evaluated for tar and methane reforming performance with oak and model syngas in two types of pilot scale fluidized reactors (recirculating and recirculating regenerating). Because hydrogen sulfide (present in raw syngas and added to model syngas) reacts with the active nickel surface, regeneration with steam and hydrogen was required. Pre and post catalyst characterization showed changes specific to the syngas type used. Results of this work will be discussed in the context of selecting the best process for pilot scale demonstration.

Magrini, K. A.; Parent, Y.; Jablonski, W.; Yung, M.

2012-01-01T23:59:59.000Z

476

Method for selective catalytic reduction of nitrogen oxides  

DOE Patents [OSTI]

A method for catalytically reducing nitrogen oxide compounds (NO.sub.x, defined as nitric oxide, NO, +nitrogen dioxide, NO.sub.2) in a gas by a material comprising a base metal consisting essentially of CuO and Mn, and oxides of Mn, on an activated metal hydrous metal oxide support, such as HMO:Si. A promoter, such as tungsten oxide or molybdenum oxide, can be added and has been shown to increase conversion efficiency. This method provides good conversion of NO.sub.x to N.sub.2, good selectivity, good durability, resistance to SO.sub.2 aging and low toxicity compared with methods utilizing vanadia-based catalysts.

Mowery-Evans, Deborah L. (Broomfield, CO); Gardner, Timothy J. (Albuquerque, NM); McLaughlin, Linda I. (Albuquerque, NM)

2005-02-15T23:59:59.000Z

477

Method For Selective Catalytic Reduction Of Nitrogen Oxides  

DOE Patents [OSTI]

A method for catalytically reducing nitrogen oxide compounds (NO.sub.x, defined as nitric oxide, NO, +nitrogen dioxide, NO.sub.2) in a gas by a material comprising a base metal consisting essentially of CuO and Mn, and oxides of Mn, on an activated metal hydrous metal oxide support, such as HMO:Si. A promoter, such as tungsten oxide or molybdenum oxide, can be added and has been shown to increase conversion efficiency. This method provides good conversion of NO.sub.x to N.sub.2, good selectivity, good durability, resistance to SO.sub.2 aging and low toxicity compared with methods utilizing vanadia-based catalysts.

Mowery-Evans, Deborah L. (Broomfield, CO); Gardner, Timothy J. (Albuquerque, NM); McLaughlin, Linda I. (Albuquerque, NM)

2005-02-15T23:59:59.000Z

478

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

479

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

480

Catalytic Hydrogenation of Bio-Oil for Chemicals and Fuels  

SciTech Connect (OSTI)

The scope of work includes optimizing processing conditions and demonstrating catalyst lifetime for catalyst formulations that are readily scaleable to commercial operations. We use a bench-scale, continuous-flow, packed-bed, catalytic, tubular reactor, which can be operated in the range of 100-400 mL/hr., from 50-400 C and up to 20MPa (see Figure 1). With this unit we produce upgraded bio-oil from whole bio-oil or useful bio-oil fractions, specifically pyrolytic lignin. The product oils are fractionated, for example by distillation, for recovery of chemical product streams. Other products from our tests have been used in further testing in petroleum refining technology at UOP and fractionation for product recovery in our own lab. Further scale-up of the technology is envisioned and we will carry out or support process design efforts with industrial partners, such as UOP.

Elliott, Douglas C.

2006-02-14T23:59:59.000Z

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

Methods and apparatus for catalytic hydrothermal gasification of biomass  

DOE Patents [OSTI]

Continuous processing of wet biomass feedstock by catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent separation of sulfur contaminants, or combinations thereof. Treatment further includes separating the precipitates out of the wet feedstock, removing sulfur contaminants, or both using a solids separation unit and a sulfur separation unit, respectively. Having removed much of the inorganic wastes and the sulfur that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogeneous catalyst for gasification.

Elliott, Douglas C.; Butner, Robert Scott; Neuenschwander, Gary G.; Zacher, Alan H.; Hart, Todd R.

2012-08-14T23:59:59.000Z

482

An Energy Analysis of the Catalytic Combustion Burner  

E-Print Network [OSTI]

ICEBO2006, Shenzhen, China Heating technologies for energy efficiency Vol.III-1-3 An Energy Analysis of the Catalytic Combustion Burner Qingshan Dong Postgraduate Shihong. Zhang Ph. D. Professor Zhiyin Duan Postgraduate Qi Zhou... for energy efficiency Vol.III-1-3 Tab. 1 Compositions of natural gas Compositions CH4 C2H6 C3H8 i-C4H10 n-C4H10 CO2 N2 O2 Volume fraction (%) 93.908 0.951 0.198 0.012 0.011 2.657 1.894 0.369 Lower heating value (kJ Nm-3) 35906 64397 93244 122857...

Dong, Q.; Zhang, S.; Duan, Z.; Zhou, Q.

2006-01-01T23:59:59.000Z

483

Studies of coupled chemical and catalytic coal conversion methods  

SciTech Connect (OSTI)

The objective of this research was to convert coal into a soluble substance under mild conditions. The strategy involved two steps, first to breakdown the macromolecular network of coal, and second to add hydrogen catalytically. We investigated different basic reagents that could, in priciple, break down coal's structure and alkylation strategies that might enhance its solubility. We examined O- and C-alkylation, the importance of the strength of the base, the character of the added alkyl groups and other reaction parameters. This work provided new information concerning the way in which hydrogen bonding, polarization interactions between aromatic structures and covalent bonding could be disrupted and solubility enhanced. The objective of our research was to explore new organochromium chemistry that might be feasible for the hydrogenation of coal under mild conditions.

Stock, L.M.; Chatterjee, K.; Cheng, C.; Ettinger, M.; Flores, F.; Jiralerspong, S.; Miyake, M.; Muntean, J.

1991-12-01T23:59:59.000Z

484

Studies of coupled chemical and catalytic coal conversion methods  

SciTech Connect (OSTI)

The objective of this research was to convert coal into a soluble substance under mild conditions. The strategy involved two steps, first to breakdown the macromolecular network of coal, and second to add hydrogen catalytically. We investigated different basic reagents that could, in priciple, break down coal`s structure and alkylation strategies that might enhance its solubility. We examined O- and C-alkylation, the importance of the strength of the base, the character of the added alkyl groups and other reaction parameters. This work provided new information concerning the way in which hydrogen bonding, polarization interactions between aromatic structures and covalent bonding could be disrupted and solubility enhanced. The objective of our research was to explore new organochromium chemistry that might be feasible for the hydrogenation of coal under mild conditions.

Stock, L.M.; Chatterjee, K.; Cheng, C.; Ettinger, M.; Flores, F.; Jiralerspong, S.; Miyake, M.; Muntean, J.

1991-12-01T23:59:59.000Z

485

Catalytic carbon membranes for hydrogen production. Final report  

SciTech Connect (OSTI)

Commercial carbon composite microfiltration membranes may be modified for gas separation applications by providing a gas separation layer with pores in the 1- to 10-nm range. Several organic polymeric precursors and techniques for depositing a suitable layer were investigated in this project. The in situ polymerization technique was found to be the most promising, and pure component permeation tests with membrane samples prepared with this technique indicated Knudsen diffusion behavior. The gas separation factors obtained by mixed-gas permeation tests were found to depend strongly on gas temperature and pressure indicating significant viscous flow at high-pressure conditions. The modified membranes were used to carry out simultaneous water gas shift reaction and product hydrogen separation. These tests indicated increasing CO conversions with increasing hydrogen separation. A simple process model was developed to simulate a catalytic membrane reactor. A number of simulations were carried out to identify operating conditions leading to product hydrogen concentrations over 90 percent. (VC)

Damle, A.S.; Gangwal, S.K.

1992-01-01T23:59:59.000Z

486

Visible light plasmonic heating of Au-ZnO for the catalytic reduction of CO{sub 2}  

SciTech Connect (OSTI)

Plasmonic excitation of Au nanoparticles attached to the surface of ZnO catalysts using low power 532 nm laser illumination leads to significant heating of the catalyst and the conversion of CO{sub 2} and H{sub 2} reactants to CH{sub 4} and CO products. Temperature-calibrated Raman spectra of ZnO phonons show that intensity-dependent plasmonic excitation can controllably heat Au–ZnO from 30 to #1;~600 {degrees}#3;C and simultaneously tune the CH{sub 4} : CO product ratio. The laser induced heating and resulting CH{sub 4} : CO product distribution agrees well with predictions from thermodynamic models and temperatureprogrammed reaction experiments indicating that the reaction is a thermally driven process resulting from the plasmonic heating of the Au–ZnO. The apparent quantum yield for CO{sub 2} conversion under continuous wave (cw) 532 nm laser illumination is 0.030%. The Au–ZnO catalysts are robust and remain active after repeated laser exposure and cycling. The light intensity required to initiate CO{sub 2} reduction is low (#1;~2.5 x#4; 10{sup 5} W m{sup #5;-2}) and achievable with solar concentrators. Our results illustrate the viability of plasmonic heating approaches for CO{sub 2} utilization and other practical thermal catalytic applications.

Wang, Congjun; Ranasingha, Oshadha; Natesakhawat, Sittichai; Ohodnicki, Paul R.; Ohodnicki, Andio, Mark; Lewis, James; P Matranga, Christopher

2013-05-01T23:59:59.000Z

487

Catalytic gasification studies in a pressurized fluid-bed unit  

SciTech Connect (OSTI)

The purpose of the project is to evaluate the technical and economic feasibility of producing specific gas products via the catalytic gasification of biomass. This report presents the results of research conducted from October 1980 to November 1982. In the laboratory scale studis, active catalysts were developed for generation of synthesis gases from wood by steam gasification. A trimetallic catalyst, Ni-Co-Mo on silica-alumina doped with 2 wt % Na, was found to retain activity indefinitely for generation of a methanol synthesis gas from wood at 1380/sup 0/F (750/sup 0/C) and 1 atm (100 kPa) absolute pressure. Catalysts for generation of a methane-rich gas were deactivated rapidly and could not be regenerated as required for economic application. Sodium carbonate and potassium carbonate were effective as catalysts for conversion of wood to synthesis gases and methane-rich gas and should be economically viable. Catalytic gasification conditions were found to be suitable for processing of alternative feedstocks: bagasse, alfalfa, rice hulls, and almond hulls. The PDU was operated successfully at absolute pressures of up to 10 atm (1000 kPa) and temperatures of up to 1380/sup 0/F (750/sup 0/C). Yields of synthesis gases at elevated pressure were greater than those used for previous economic evaluations. A trimetallic catalyst, Ni-Cu-Mo on silica-alumina, did not display a long life as did the doped trimetallic catalyst used in laboratory studies. A computer program for a Radio Shack TRS-80 Model I microcomputer was developed to evaluate rapidly the economics of producing either methane or methanol from wood. The program is based on economic evaluations reported in previous studies. Improved yields from the PDU studies were found to result in a reduction of about 9 cents/gal in methanol cost.

Mudge, L.K.; Baker, E.G.; Mitchell, D.H.; Robertus, R.J.; Brown, M.D.

1983-07-01T23:59:59.000Z

488

Catalytic Synthesis of Oxygenates: Mechanisms, Catalysts and Controlling Characteristics  

SciTech Connect (OSTI)

This research focused on catalytic synthesis of unsymmetrical ethers as a part of a larger program involving oxygenated products in general, including alcohols, ethers, esters, carboxylic acids and their derivatives that link together environmentally compliant fuels, monomers, and high-value chemicals. The catalysts studied here were solid acids possessing strong Br�������¸nsted acid functionalities. The design of these catalysts involved anchoring the acid groups onto inorganic oxides, e.g. surface-grafted acid groups on zirconia, and a new class of mesoporous solid acids, i.e. propylsulfonic acid-derivatized SBA-15. The former catalysts consisted of a high surface concentration of sulfate groups on stable zirconia catalysts. The latter catalyst consists of high surface area, large pore propylsulfonic acid-derivatized silicas, specifically SBA-15. In both cases, the catalyst design and synthesis yielded high concentrations of acid sites in close proximity to one another. These materials have been well-characterization in terms of physical and chemical properties, as well as in regard to surface and bulk characteristics. Both types of catalysts were shown to exhibit high catalytic performance with respect to both activity and selectivity for the bifunctional coupling of alcohols to form ethers, which proceeds via an efficient SN2 reaction mechanism on the proximal acid sites. This commonality of the dual-site SN2 reaction mechanism over acid catalysts provides for maximum reaction rates and control of selectivity by reaction conditions, i.e. pressure, temperature, and reactant concentrations. This research provides the scientific groundwork for synthesis of ethers for energy applications. The synthesized environmentally acceptable ethers, in part derived from natural gas via alcohol intermediates, exhibit high cetane properties, e.g. methylisobutylether with cetane No. of 53 and dimethylether with cetane No. of 55-60, or high octane properties, e.g. diisopropylether with blending octane No. of 105, and can replace aromatics in liquid fuels.

Kamil Klier; Richard G. Herman

2005-11-30T23:59:59.000Z

489

Studies on the disbonding initiation of interfacial cracks.  

SciTech Connect (OSTI)

With the continuing trend of decreasing feature sizes in flip-chip assemblies, the reliability tolerance to interfacial flaws is also decreasing. Small-scale disbonds will become more of a concern, pointing to the need for a better understanding of the initiation stage of interfacial delamination. With most accepted adhesion metric methodologies tailored to predict failure under the prior existence of a disbond, the study of the initiation phenomenon is open to development and standardization of new testing procedures. Traditional fracture mechanics approaches are not suitable, as the mathematics assume failure to originate at a disbond or crack tip. Disbond initiation is believed to first occur at free edges and corners, which act as high stress concentration sites and exhibit singular stresses similar to a crack tip, though less severe in intensity. As such, a 'fracture mechanics-like' approach may be employed which defines a material parameter--a critical stress intensity factor (K{sub c})--that can be used to predict when initiation of a disbond at an interface will occur. The factors affecting the adhesion of underfill/polyimide interfaces relevant to flip-chip assemblies were investigated in this study. The study consisted of two distinct parts: a comparison of the initiation and propagation phenomena and a comparison of the relationship between sub-critical and critical initiation of interfacial failure. The initiation of underfill interfacial failure was studied by characterizing failure at a free-edge with a critical stress intensity factor. In comparison with the interfacial fracture toughness testing, it was shown that a good correlation exists between the initiation and propagation of interfacial failures. Such a correlation justifies the continuing use of fracture mechanics to predict the reliability of flip-chip packages. The second aspect of the research involved fatigue testing of tensile butt joint specimens to determine lifetimes at sub-critical load levels. The results display an interfacial strength ranking similar to that observed during monotonic testing. The fatigue results indicate that mo