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Selective methane oxidation over promoted oxide catalysts. Quarterly report, June--August 1995

Description: The partial oxidation of methane to oxygenates involves a complex network of heterogeneous and homogeneous free radical reactions, particularly under higher temperatures and pressures. It is generally difficult to separately study the relative importance of each of these types of reactions during the reaction process by experimental means. However, in order to maximize the oxygenate yields, better reactor/reaction designs, such as the double-bed reactor configuration explored previously in this project, are needed. For these tasks, it is often necessary to understand the extent to which each of these two different types of reactions contributes to the reaction process. Therefore, during this quarter, efforts were made in this aspect through a kinetic modeling approach. With such an approach, one can readily examine the contribution of each and every reaction step in the reaction process, simply by including or excluding it from the model.
Date: October 1, 1995
Partner: UNT Libraries Government Documents Department

Conversion of high carbon refinery by-products. Quarterly report, July 1--September 30, 1996

Description: The overall objective of the project is to demonstrate that a partial oxidation system, which utilizes a transport reactor, is a viable means of converting refinery wastes, byproducts, and other low value materials into valuable products. The primary product would be a high quality fuel gas, which could also be used as a source of hydrogen. The concept involves subjecting the hydrocarbon feed to pyrolysis and steam gasification in a circulating bed of solids. Carbon residue formed during pyrolysis, as well as metals in the feed, are captured by the circulating solids which are returned to the bottom of the transport reactor. Air or oxygen is introduced in this lower zone and sufficient carbon is burned, sub-stoichiometrically, to provide the necessary heat for the endothermic pyrolysis and gasification reactions. The hot solids and gases leaving this zone pass upward to contact the feed material and continue the gasification process. Tests were conducted in the Transport Reactor Test Unit (TRTU) to study gasification and combustion of Rose Bottoms solids using the spent FCC (Fluid Catalytic Cracker) catalyst as the circulating medium and petroleum coke at temperature of 1,750 F. The Rose (Residuum Oil Supercritical Extraction) bottoms was produced in the Kellogg`s Rose unit. A dry solid feed system developed previously was used to feed petroleum coke and Rose Bottoms. Studies were also done in the Bench Scale Reactor Unit (BRU) to investigate partial oxidation and gasification of petroleum coke over temperature range of 1,800 F to 2,100 F. Results obtained in the BRU and TRTU on petroleum coke formed the basis to develop a flowsheet to process this material in a transport reactor. Results from these studies are presented in this report.
Date: October 18, 1996
Creator: Katta, S.; Henningsen, G.; Lin, Y.Y. & Agrawal, R.
Partner: UNT Libraries Government Documents Department

Hydrogen production costs -- A survey

Description: Hydrogen, produced using renewable resources, is an environmentally benign energy carrier that will play a vital role in sustainable energy systems. The US Department of Energy (DOE) supports the development of cost-effective technologies for hydrogen production, storage, and utilization to facilitate the introduction of hydrogen in the energy infrastructure. International interest in hydrogen as an energy carrier is high. Research, development, and demonstration (RD and D) of hydrogen energy systems are in progress in many countries. Annex 11 of the International Energy Agency (IEA) facilitates member countries to collaborate on hydrogen RD and D projects. The United States is a member of Annex 11, and the US representative is the Program Manager of the DOE Hydrogen R and D Program. The Executive Committee of the Hydrogen Implementing Agreement in its June 1997 meeting decided to review the production costs of hydrogen via the currently commercially available processes. This report compiles that data. The methods of production are steam reforming, partial oxidation, gasification, pyrolysis, electrolysis, photochemical, photobiological, and photoelectrochemical reactions.
Date: December 4, 1997
Creator: Basye, L. & Swaminathan, S.
Partner: UNT Libraries Government Documents Department

Conversion of high carbon refinery by-products. Quarterly technical report, April 1--June 30, 1996

Description: The overall objective of the project is to demonstrate that a partial oxidation system, which utilizes a transport reactor, is a viable means of converting refinery wastes, byproducts, and other low value materials into valuable products. The primary product would be a high quality fuel gas, which could also be used as a source of hydrogen. The concept involves subjecting the hydrocarbon feed to pyrolysis and steam gasification in a circulating bed of solids. Carbon residues formed during pyrolysis, and metals in the feed, are captured by the circulating solids which are returned to the bottom of the transport reactor. Air or oxygen is introduced in this lower zone and sufficient carbon is burned, sub-stoichiometrically, to provide the necessary heat for the endothermic pyrolysis and gasification reactions. The hot solids and gases leaving this zone pass upward to contact the feed material and continue the gasification process. Tests were conducted in the Transport Reactor Test Unit (TRTU) to study gasification and combustion of Rose Bottoms using the spent FCC (Fluid Catalytic Cracker) catalyst as the circulating medium at temperature of 1,690 F. The Rose (Residuum Oil Supercritical Extraction) bottoms was produced in the Kellogg`s Rose unit. Studies were done in the Bench Scale Reactor Unit (BRU) to characterize petroleum coke with respect to pyrolysis and agglomeration tendency upon heating to 1,800 F. Studies were conducted in the CFS (Cold Flow Simulator) to determine the various aeration flowrates required for satisfactory circulation of petroleum coke in the TRTU. Results from these studies are presented in this report. A dry solid feed system was developed and tested for use in the fourth quarter.
Date: July 12, 1996
Creator: Katta, S.; Henningsen, G.; Lin, Y.Y. & Agrawal, R.
Partner: UNT Libraries Government Documents Department

Transient studies of low temperature catalysts for methane conversion. Quarterly technical progress report, April 1, 1995--June 30, 1995

Description: Previous results showed that a 3% Rh/TiO{sub 2} catalyst was active for the partial oxidation of methane to synthesis gas at temperatures significantly lower than those previously reported in the literature. Schmidt and coworkers have shown that Rh deposited on a monolith support operating at millisecond residence times exhibits high selectivity to CO and H{sub 2} and high methane conversion. The operation of the Rh monolith catalyst requires that ignition be carried out at high temperatures of about 600{degrees}C using ammonia oxidation to ignite the catalysts and avoid excursions into the explosive methane/oxygen mixtures. The 3% Rh/TiO{sub 2} catalyst ignites at much lower temperatures which permits the direct ignition of the methane oxygen mixture under safer conditions than reported by Schmidt and coworkers. In order to study the effect of the operation variables on the activity and selectivity of the 3% Rh/TiO{sub 2} catalysts we conducted steady state experiments at low conversion prior to ignition. Experiments were also conducted at high conversion after ignition.
Date: January 1, 1996
Creator: Wolf, E.E.
Partner: UNT Libraries Government Documents Department

Conversion of high carbon refinery by-products. Quarterly report, October 1--December 31, 1995

Description: The overall objective of the project is to demonstrate that a partial oxidation system, which utilizes a transport reactor, is a viable means of converting refinery wastes, byproducts, and other low value materials into valuable products. The primary product would be a high quality fuel gas, which could also be used as a source of hydrogen. The concept involves subjecting the hydrocarbon feed to pyrolysis and steam gasification in a circulating bed of solids. Carbon residue formed during pyrolysis, as well as metals in the feed, are captured by the circulating solids which are returned to the bottom of the transport reactor. Air or oxygen is introduced in this lower zone and sufficient carbon is burned, sub-stoichiometrically, to provide the necessary heat for the endothermic pyrolysis and gasification reactions. The hot solids and gases leaving this zone pass upward to contact the feed material and continue the partial oxidation process. Studies were conducted in the Transport Reactor Test Unit (TRTU) to pyrolyze naphtha with untreated as well as potassium-impregnated spent FCC (Fluid Catalytic Cracker) catalyst as the circulating medium over a temperature range of 1,400 to 1,600 F. The results from these studies are presented and discussed here. Studies were also performed in the Bench Scale Reactor Unit (BRU) in an effort to develop suitable catalyst formulations and to study the steam reforming of methane and propane in support of the experiments conducted in the TRTU. The results from these studies are also presented here. A Cold Flow Simulator (CFS) was designed and built to investigate the flow problems experienced in the TRTU.
Date: January 19, 1996
Creator: O`Donnell, J.; Katta, S.; Henningsen, G. & Lin, Y.Y.
Partner: UNT Libraries Government Documents Department

Oxygen-permeable ceramic membranes for gas separation

Description: Mixed-conducting oxides have a wide range of applications, including fuel cells, gas separation systems, sensors, and electrocatalytic equipment. Dense ceramic membranes made of mixed-conducting oxides are particularly attractive for gas separation and methane conversion processes. Membranes made of Sr-Fe-Co oxide, which exhibits high combined electronic and oxygen ionic conductivities, can be used to selectively transport oxygen during the partial oxidation of methane to synthesis gas (syngas, i.e., CO + H{sub 2}). The authors have fabricated tubular Sr{sub 2}Fe{sub 2}CoO{sub 6+{delta}} membranes and tested them (some for more than 1,000 h) in a methane conversion reactor that was operating at 850--950 C. An oxygen permeation flux of {approx} 10 scc/cm{sup 2} {center_dot} min was obtained at 900 C in a tubular membrane with a wall thickness of 0.75 mm. Using a gas-tight electrochemical cell, the authors have also measured the steady-state oxygen permeability of flat Sr{sub 2}Fe{sub 2}CoO{sub 6+{delta}} membranes as a function of temperature and oxygen partial pressure(pO{sub 2}). Steady-state oxygen permeability increases with increasing temperature and with the difference in pO{sub 2} on the two sides of the membrane. At 900 C, an oxygen permeability of {approx} 2.5 scc/cm{sup 2} {center_dot} min was obtained in a 2.9-mm-thick membrane. This value agrees with that obtained in methane conversion reactor experiments. Current-voltage (I-V) characteristics determined in the gas-tight cell indicate that bulk effect, rather than surface exchange effect, is the main limiting factor for oxygen permeation of {approx} 1-mm-thick Sr{sub 2}Fe{sub 2}CoO{sub 6+{delta}} membranes at elevated temperatures (> 650 C).
Date: February 1, 1998
Creator: Balachandran, U.; Ma, B.; Maiya, P.S.; Dusek, J.T.; Mieville, R.L. & Picciolo, J.J.
Partner: UNT Libraries Government Documents Department

Exhaust aftertreatment using plasma-assisted catalysis

Description: In the field of catalysis, one application that has been classified as a breakthrough technology is the catalytic reduction of NO{sub x} in oxygen-rich environments using hydrocarbons. This breakthrough will require dramatic improvements in both catalyst and engine technology, but the benefits will be substantial for energy efficiency and a cleaner environment. Engine and automobile companies are placing greater emphasis on the diesel engine because of its potential for saving fuel resources and reducing CO{sub 2} emissions. The modern direct-injection diesel engine offers demonstrated fuel economy advantages unmatched by any other commercially-viable engine. The main drawback of diesel engines is exhaust emissions. A modification of existing oxidation catalyst/engine technology is being used to address the CO, hydrocarbon and particulates. However, no satisfactory solution currently exists for NO{sub x}. Diesel engines operate under net oxidizing conditions, thus rendering conventional three-way catalytic converters ineffective for the controlling the NO{sub x} emission. NO{sub x} reduction catalysts, using ammonia as a reductant, do exist for oxygen-rich exhausts; however, for transportation applications, the use of on-board hydrocarbon fuels is a more feasible, cost-effective, and environmentally-sound approach. Selective catalytic reduction (SCR) by hydrocarbons is one of the leading catalytic aftertreatment technologies for the reduction of NO{sub x} in lean-burn engine exhaust (often referred to as lean-NO{sub x}). The objective is to chemically reduce the pollutant molecules of NO{sub x} to benign molecules such as N{sub 2}. Aftertreatment schemes have focused a great deal on the reduction of NO because the NO{sub x} in engine exhaust is composed primarily of NO. Recent studies, however, have shown that the oxidation of NO to NO{sub 2} serves an important role in enhancing the efficiency for reduction of NO{sub x} to N{sub 2}. It has become apparent that preconverting NO to NO{sub 2} could improve both the efficiency and durability ...
Date: January 20, 2000
Creator: Penetrante, B
Partner: UNT Libraries Government Documents Department

Experimental Evaluation of SI Engine Operation Supplemented by Hydrogen Rich Gas from a Compact Plasma Boosted Reformer

Description: It is well known that hydrogen addition to spark-ignited (SI) engines can reduce exhaust emissions and increase efficiency. Micro plasmatron fuel converters can be used for onboard generation of hydrogen-rich gas by partial oxidation of a wide range of fuels. These plasma-boosted microreformers are compact, rugged, and provide rapid response. With hydrogen supplement to the main fuel, SI engines can run very lean resulting in a large reduction in nitrogen oxides (NO x ) emissions relative to stoichiometric combustion without a catalytic converter. This paper presents experimental results from a microplasmatron fuel converter operating under variable oxygen to carbon ratios. Tests have also been carried out to evaluate the effect of the addition of a microplasmatron fuel converter generated gas in a 1995 2.3-L four-cylinder SI production engine. The tests were performed with and without hydrogen-rich gas produced by the plasma boosted fuel converter with gasoline. A one hundred fold reduction in NO x due to very lean operation was obtained under certain conditions. An advantage of onboard plasma-boosted generation of hydrogen-rich gas is that it is used only when required and can be readily turned on and off. Substantial NO x reduction should also be obtainable by heavy exhaust gas recirculation (EGR) facilitated by use of hydrogen-rich gas with stoichiometric operation.
Date: June 19, 2000
Creator: Green, J. B., Jr.; Domingo, N.; Storey, J. M. E.; Wagner, R.M.; Armfield, J.S.; Bromberg, L. et al.
Partner: UNT Libraries Government Documents Department

Method for producing low-cost, high volume hydrogen from hydrocarbon sources

Description: A method is described for the conversion of naturally-occurring or biomass-derived lower to higher hydrocarbon (C{sub x}H{sub y},where x may vary from 1--3 and y may vary from 4--8) to low-cost, high-volume hydrogen. In one embodiment, methane, the major component of natural gas, is reacted in a single reaction zone of a mixed-conducting ceramic membrane reactor to form hydrogen via simultaneous partial oxidation and water gas shift reactions at temperatures required for thermal excitations of the mixed-conducting membranes. The hydrogen is produced by catalytically reacting the hydrocarbon with oxygen to form synthesis gas (a mixture of carbon monoxide and hydrogen), followed by a water gas shift (WGS) reaction with steam, wherein both reactions occur in a single reaction zone having a multi-functional catalyst or a combination of catalysts. The hydrogen is separated from other reaction products by membrane-assisted transport or by pressure-swing adsorption technique. Membrane-assisted transport may occur via proton transfer or molecular sieving mechanisms.
Date: December 1, 1997
Creator: Bose, Arun C.; Balachandran, Uthamalinga; Kleerfisch, Mark S.; Udovich, Carl A. & Stiegel, Gary J.
Partner: UNT Libraries Government Documents Department

OXYGEN TRANSPORT CERAMIC MEMBRANES

Description: Conversion of natural gas to liquid fuels and chemicals is a major goal for the Nation as it enters the 21st Century. Technically robust and economically viable processes are needed to capture the value of the vast reserves of natural gas on Alaska's North Slope, and wean the Nation from dependence on foreign petroleum sources. Technologies that are emerging to fulfill this need are all based syngas as an intermediate. Syngas (a mixture of hydrogen and carbon monoxide) is a fundamental building block from which chemicals and fuels can be derived. Lower cost syngas translates directly into more cost-competitive fuels and chemicals. The currently practiced commercial technology for making syngas is either steam methane reforming (SMR) or a two-step process involving cryogenic oxygen separation followed by natural gas partial oxidation (POX). These high-energy, capital-intensive processes do not always produce syngas at a cost that makes its derivatives competitive with current petroleum-based fuels and chemicals. This project has the following 6 main tasks: Task 1--Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. Task 2--Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. Task 3--Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. Task 4--Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. Task 5--Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. Task 6--Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.
Date: December 1, 2001
Creator: Bandopadhyay, Sukumar & Nagabhushana, Nagendra
Partner: UNT Libraries Government Documents Department

Direct methane conversion to methanol. Final report, April 13, 1995--September 30, 1996

Description: We proposed to demonstrate the effectiveness of a catalytic membrane reactor (a ceramic membrane combined with a catalyst) to selectively produce methanol by partial oxidation of methane. Methanol is used as a chemical feed stock, gasoline additive, and turbine fuel. Methane partial oxidation using a catalytic membrane reactor has been determined as one of the promising approaches for methanol synthesis from methane. Methanol synthesis and separation in one step would also make methane more valuable for producing chemicals and fuels. Another valuable fuel product is H{sub 2}. Its separation from other gasification products would make it very valuable as a chemical feedstock and clean fuel for fuel cells. Gasification of coal or other organic fuels as a source of H{sub 2} produces compounds (CO, CO{sub 2}, and H{sub 2}O) that require high temperature (1000-1500 degrees F) and high pressure (600-1000 psia) separations. A zeolite membrane layer on a mechanically stable ceramic or stainless steel support would have ideal applications for this type of separation.
Date: January 1, 1998
Creator: Noble, R.D. & Falconer, J.L.
Partner: UNT Libraries Government Documents Department

Conversion of high carbon refinery by-products. Annual technical report, fiscal year 1995 (October 1994--September 1995)

Description: The overall objective of the project is to demonstrate that a partial oxidation system, which utilizes a transport reactor, is a viable mans of converting refinery wastes, byproducts, and other low-value materials into valuable products. The primary product would be a high quality fuel gas, which could also be used as a source of hydrogen. The concept involves subjecting the hydrocarbon feed material to pyrolysis and steam gasification in a circulating bed of solids. Carbon residue formed during pyrolysis, as well as metals in the feed, are captured by the circulating solids, which are returned to the bottom of the transport reactor. Air or oxygen is introduced in this lower zone and sufficient carbon is burned, sub-stoichiometrically, to provide the necessary heat for the endothermic pyrolysis and gasification reactions. The hot solids an gases leaving this zone pass upward to contact the feed material and continue the partial oxidation process. At the end of FY94, a limited number of pyrolysis runs were made using an oil in water emulsion of Hondo crude as the feed material. It was intended to conduct these tests in the fully integrated partial oxidation mode. At the completion of the tests, it was concluded that the reactor configuration was not suitable for handling highly coking liquid hydrocarbon feeds. The decision was made to design and build a new reactor which, in addition to a better feed injection systems, includes other design features that improve the performance and reliability of the unit. The new design is also more suitable for integrated partial oxidation testing. The design, construction, and start-up of this reactor is described.
Date: October 1, 1995
Partner: UNT Libraries Government Documents Department

A survey of processes for producing hydrogen fuel from different sources for automotive-propulsion fuel cells

Description: Seven common fuels are compared for their utility as hydrogen sources for proton-exchange-membrane fuel cells used in automotive propulsion. Methanol, natural gas, gasoline, diesel fuel, aviation jet fuel, ethanol, and hydrogen are the fuels considered. Except for the steam reforming of methanol and using pure hydrogen, all processes for generating hydrogen from these fuels require temperatures over 1000 K at some point. With the same two exceptions, all processes require water-gas shift reactors of significant size. All processes require low-sulfur or zero-sulfur fuels, and this may add cost to some of them. Fuels produced by steam reforming contain {approximately}70-80% hydrogen, those by partial oxidation {approximately}35-45%. The lower percentages may adversely affect cell performance. Theoretical input energies do not differ markedly among the various processes for generating hydrogen from organic-chemical fuels. Pure hydrogen has severe distribution and storage problems. As a result, the steam reforming of methanol is the leading candidate process for on-board generation of hydrogen for automotive propulsion. If methanol unavailability or a high price demands an alternative process, steam reforming appears preferable to partial oxidation for this purpose.
Date: March 1, 1996
Creator: Brown, L.F.
Partner: UNT Libraries Government Documents Department

Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report 10, July 1, 1995--September 31, 1995

Description: This document is the tenth quarterly technical progress report under Contract No. DE-AC22-92PC92110 {open_quotes}Development of Vanadium-Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane{close_quotes}. Activities focused on testing of additional modified and promoted catalysts and characterization of these materials. Attempts at improving the sensitivity of our GC based analytical systems were also made with some success. Methanol oxidation studies were initiated. These results are reported. Specific accomplishments include: (1) Methane oxidation testing of a suite of catalysts promoted with most of the first row transition metals was completed. Several of these materials produced low, difficult to quantify yields of formaldehyde. (2) Characterization of these materials by XRD and FTIR was performed with the goal of correlating activity and selectivity with catalyst properties. (3) We began to characterize catalysts prepared via modified synthesis methods designed to enhance acidity using TGA measurements of acetonitrile chemisorption and methanol dehydration to dimethyl ether as a test reaction. (4) A catalyst prepared in the presence of naphthalene methanol as a structural disrupter was tested for activity in methane oxidation. It was found that this material produced low yields of formaldehyde which were difficult to quantify. (5) Preparation of catalysts with no Bronsted acid sites. This was accomplished by replacement of exchangeable protons with potassium, and (6) Methanol oxidation studies were initiated to provide an indication of catalyst activity for decomposition of this desired product and as a method of characterizing the catalyst surface.
Date: December 7, 1995
Creator: McCormick, R.L.
Partner: UNT Libraries Government Documents Department

SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

Description: Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter (January-March/99), in-situ formaldehyde generation and condensation with methyl propionate were tested over various catalysts and reaction conditions. The patent application is in preparation and the results are retained for future reports.
Date: April 21, 1999
Creator: Gogate, Makarand R.; Spivey, James J.; Zoeller, Joseph R.; Colberg, Richard D.; Choi, Gerald N. & Tam, Samuel S.
Partner: UNT Libraries Government Documents Department

A Partial Oxidation Technique for Fuel-Cell Anode Exhaust-Gas Synthesis

Description: This paper describes the performance of a gas generator used to synthesize the exhaust gas from the anode of a molten-carbonate fuel cell. The composition of this gas is estimated to be that of equilibrium at 1,250 &deg; F and 1 atm: 48% CO<sub>2</sub> , 39% H<sub>2</sub>O, 5% CO, and 8% H<sub>2</sub>, with an energy content of approximately 39 Btu/scf (higher heating value). To synthesize a range of gas compositions around this point, the gas generator partially oxidizes a mixture of CH<sub>4</sub> , O<sub>2</sub> , and CO<sub>2</sub> to generate energy densities between 20 and 60 Btu/scf at temperatures between 1,198 and 1,350 &deg; F. Results show that the technique provides a relatively high ratio of CO to H2 concentrations compared with the target composition (CO:H<sub>2</sub> of 2, versus 0.71). A detailed chemical model shows that the likely cause is quenching of the CO and H<sub>2</sub> chemistry below 2,000 &deg; F.
Date: November 10, 1998
Creator: Edward H. Robey, Jr. & Gemmen, Randall S.
Partner: UNT Libraries Government Documents Department

Quick-start catalyzed methanol partial oxidation reformer

Description: The catalytic methanol partial oxidation reformer described in this paper offers all the necessary attributes for use in transportation fuel cell systems. The bench-scale prototype methanol reformer developed at Argonne is a cylindrical reactor loaded with copper zinc oxide catalyst. Liquid methanol, along with a small amount of water, is injected as a fine spray into a flowing air stream, past an igniter onto the catalyst bed where the partial oxidation reaction takes place.
Date: December 1, 1995
Creator: Ahmed, S. & Kumar, R.
Partner: UNT Libraries Government Documents Department

Fuels processing for transportation fuel cell systems

Description: Fuel cells primarily use hydrogen as the fuel. This hydrogen must be produced from other fuels such as natural gas or methanol. The fuel processor requirements are affected by the fuel to be converted, the type of fuel cell to be supplied, and the fuel cell application. The conventional fuel processing technology has been reexamined to determine how it must be adapted for use in demanding applications such as transportation. The two major fuel conversion processes are steam reforming and partial oxidation reforming. The former is established practice for stationary applications; the latter offers certain advantages for mobile systems and is presently in various stages of development. This paper discusses these fuel processing technologies and the more recent developments for fuel cell systems used in transportation. The need for new materials in fuels processing, particularly in the area of reforming catalysis and hydrogen purification, is discussed.
Date: July 1, 1995
Creator: Kumar, R. & Ahmed, S.
Partner: UNT Libraries Government Documents Department

OXYGEN TRANSPORT CERAMIC MEMBRANES

Description: Conversion of natural gas to liquid fuels and chemicals is a major goal for the Nation as it enters the 21st Century. Technically robust and economically viable processes are needed to capture the value of the vast reserves of natural gas on Alaska's North Slope, and wean the Nation from dependence on foreign petroleum sources. Technologies that are emerging to fulfill this need are all based syngas as an intermediate. Syngas (a mixture of hydrogen and carbon monoxide) is a fundamental building block from which chemicals and fuels can be derived. Lower cost syngas translates directly into more cost-competitive fuels and chemicals. The currently practiced commercial technology for making syngas is either steam methane reforming (SMR) or a two-step process involving cryogenic oxygen separation followed by natural gas partial oxidation (POX). These high-energy, capital-intensive processes do not always produce syngas at a cost that makes its derivatives competitive with current petroleum-based fuels and chemicals.
Date: January 1, 2002
Creator: Bandopadhyay, Dr. Sukumar & Nagabhushana, Dr. Nagendra
Partner: UNT Libraries Government Documents Department

Transient studies of low temperature catalysts for methane conversion. Quarterly technical progress report, 1 October 1995--31 December 1995

Description: This report summarizes progress made on a new method of producing synthesis gas via partial oxidation of methane using a fast flow membrane reactor. Experiments were performed using a Rhodium catalyst in a traditional fixed bed reactor to provide a comparison to results that will be obtained in the membrane reactor.
Date: April 1, 1996
Creator: Wolf, E. E.
Partner: UNT Libraries Government Documents Department

Partial oxidation for improved cold starts in alcohol-fueled engines: Phase 2 topical report

Description: Alcohol fuels exhibit poor cold-start performance because of their low volatility. Neat alcohol engines become difficult, if not impossible, to start at temperatures close to or below freezing. Improvements in the cold-start performance (both time to start and emissions) are essential to capture the full benefits of alcohols as an alternative transportation fuel. The objective of this project was to develop a neat alcohol partial oxidation (POX) reforming technology to improve an alcohol engine`s ability to start at low temperatures (as low as {minus}30 C) and to reduce its cold-start emissions. The project emphasis was on fuel-grade ethanol (E95) but the technology can be easily extended to other alcohol fuels. Ultimately a compact, on-vehicle, ethanol POX reactor was developed as a fuel system component to produce a hydrogen-rich, fuel-gas mixture for cold starts. The POX reactor is an easily controllable combustion device that allows flexibility during engine startup even in the most extreme conditions. It is a small device that is mounted directly onto the engine intake manifold. The gaseous fuel products (or reformate) from the POX reactor exit the chamber and enter the intake manifold, either replacing or supplementing the standard ethanol fuel consumed during an engine start. The combustion of the reformate during startup can reduce engine start time and tail-pipe emissions.
Date: April 1, 1998
Partner: UNT Libraries Government Documents Department

Direct methane conversion to methanol. Annual report, October 1, 1992--September 30, 1993

Description: We proposed to demonstrate the effectiveness of a catalytic membrane reactor (a ceramic membrane combined with a catalyst) to selectively produce methanol by partial oxidation of methane. Methanol is used as a chemical feedstock, gasoline additive, and turbine fuel. Methane partial oxidation using a catalytic membrane reactor has been determined as one of the promising approaches for methanol synthesis from methane. In the original proposal, the membrane was used to selectively remove methanol from the reaction zone before carbon oxides form, thus increasing the methanol yield. Methanol synthesis and separation in one step would also make methane more valuable for producing chemicals and fuels. The cooling tube inserted inside the membrane reactor has created a low temperature zone that rapidly quenches the product stream. This system has proved effective for increasing methanol selectivity during CH{sub 4} oxidation. The membranes broke during experiments, however, apparently because of the large radial thermal gradient and axial thermal expansion difference. Our efforts concentrated on improving the membrane lifetime by modifying this non-isothermal membrane reactor.
Date: October 1, 1993
Creator: Noble, R. D. & Falconer, J. L.
Partner: UNT Libraries Government Documents Department