Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne
2015-02-01
This is the third and final part of the three-part article written to describe the mass, energy and material balances of the solid recovered fuel production process produced from various types of waste streams through mechanical treatment. This article focused the production of solid recovered fuel from municipal solid waste. The stream of municipal solid waste used here as an input waste material to produce solid recovered fuel is energy waste collected from households of municipality. This article presents the mass, energy and material balances of the solid recovered fuel production process. These balances are based on the proximate as well as the ultimate analysis and the composition determination of various streams of material produced in a solid recovered fuel production plant. All the process streams are sampled and treated according to CEN standard methods for solid recovered fuel. The results of the mass balance of the solid recovered fuel production process showed that 72% of the input waste material was recovered in the form of solid recovered fuel; 2.6% as ferrous metal, 0.4% as non-ferrous metal, 11% was sorted as rejects material, 12% as fine faction and 2% as heavy fraction. The energy balance of the solid recovered fuel production process showed that 86% of the total input energy content of input waste material was recovered in the form of solid recovered fuel. The remaining percentage (14%) of the input energy was split into the streams of reject material, fine fraction and heavy fraction. The material balances of this process showed that mass fraction of paper and cardboard, plastic (soft) and wood recovered in the solid recovered fuel stream was 88%, 85% and 90%, respectively, of their input mass. A high mass fraction of rubber material, plastic (PVC-plastic) and inert (stone/rock and glass particles) was found in the reject material stream. © The Author(s) 2014.
Removal of hydrogen sulfide as ammonium sulfate from hydropyrolysis product vapors
DOE Office of Scientific and Technical Information (OSTI.GOV)
Marker, Terry L.; Felix, Larry G.; Linck, Martin B.
A system and method for processing biomass into hydrocarbon fuels that includes processing a biomass in a hydropyrolysis reactor resulting in hydrocarbon fuels and a process vapor stream and cooling the process vapor stream to a condensation temperature resulting in an aqueous stream. The aqueous stream is sent to a catalytic reactor where it is oxidized to obtain a product stream containing ammonia and ammonium sulfate. A resulting cooled product vapor stream includes non-condensable process vapors comprising H.sub.2, CH.sub.4, CO, CO.sub.2, ammonia and hydrogen sulfide.
Removal of hydrogen sulfide as ammonium sulfate from hydropyrolysis product vapors
Marker, Terry L; Felix, Larry G; Linck, Martin B; Roberts, Michael J
2014-10-14
A system and method for processing biomass into hydrocarbon fuels that includes processing a biomass in a hydropyrolysis reactor resulting in hydrocarbon fuels and a process vapor stream and cooling the process vapor stream to a condensation temperature resulting in an aqueous stream. The aqueous stream is sent to a catalytic reactor where it is oxidized to obtain a product stream containing ammonia and ammonium sulfate. A resulting cooled product vapor stream includes non-condensable process vapors comprising H.sub.2, CH.sub.4, CO, CO.sub.2, ammonia and hydrogen sulfide.
Partial oxidation process for producing a stream of hot purified gas
Leininger, Thomas F.; Robin, Allen M.; Wolfenbarger, James K.; Suggitt, Robert M.
1995-01-01
A partial oxidation process for the production of a stream of hot clean gas substantially free from particulate matter, ammonia, alkali metal compounds, halides and sulfur-containing gas for use as synthesis gas, reducing gas, or fuel gas. A hydrocarbonaceous fuel comprising a solid carbonaceous fuel with or without liquid hydrocarbonaceous fuel or gaseous hydrocarbon fuel, wherein said hydrocarbonaceous fuel contains halides, alkali metal compounds, sulfur, nitrogen and inorganic ash containing components, is reacted in a gasifier by partial oxidation to produce a hot raw gas stream comprising H.sub.2, CO, CO.sub.2, H.sub.2 O, CH.sub.4, NH.sub.3, HCl, HF, H.sub.2 S, COS, N.sub.2, Ar, particulate matter, vapor phase alkali metal compounds, and molten slag. The hot raw gas stream from the gasifier is split into two streams which are separately deslagged, cleaned and recombined. Ammonia in the gas mixture is catalytically disproportionated into N.sub.2 and H.sub.2. The ammonia-free gas stream is then cooled and halides in the gas stream are reacted with a supplementary alkali metal compound to remove HCl and HF. Alkali metal halides, vaporized alkali metal compounds and residual fine particulate matter are removed from the gas stream by further cooling and filtering. The sulfur-containing gases in the process gas stream are then reacted at high temperature with a regenerable sulfur-reactive mixed metal oxide sulfur sorbent material to produce a sulfided sorbent material which is then separated from the hot clean purified gas stream having a temperature of at least 1000.degree. F.
Partial oxidation process for producing a stream of hot purified gas
Leininger, T.F.; Robin, A.M.; Wolfenbarger, J.K.; Suggitt, R.M.
1995-03-28
A partial oxidation process is described for the production of a stream of hot clean gas substantially free from particulate matter, ammonia, alkali metal compounds, halides and sulfur-containing gas for use as synthesis gas, reducing gas, or fuel gas. A hydrocarbonaceous fuel comprising a solid carbonaceous fuel with or without liquid hydrocarbonaceous fuel or gaseous hydrocarbon fuel, wherein said hydrocarbonaceous fuel contains halides, alkali metal compounds, sulfur, nitrogen and inorganic ash containing components, is reacted in a gasifier by partial oxidation to produce a hot raw gas stream comprising H{sub 2}, CO, CO{sub 2}, H{sub 2}O, CH{sub 4}, NH{sub 3}, HCl, HF, H{sub 2}S, COS, N{sub 2}, Ar, particulate matter, vapor phase alkali metal compounds, and molten slag. The hot raw gas stream from the gasifier is split into two streams which are separately deslagged, cleaned and recombined. Ammonia in the gas mixture is catalytically disproportionated into N{sub 2} and H{sub 2}. The ammonia-free gas stream is then cooled and halides in the gas stream are reacted with a supplementary alkali metal compound to remove HCl and HF. Alkali metal halides, vaporized alkali metal compounds and residual fine particulate matter are removed from the gas stream by further cooling and filtering. The sulfur-containing gases in the process gas stream are then reacted at high temperature with a regenerable sulfur-reactive mixed metal oxide sulfur sorbent material to produce a sulfided sorbent material which is then separated from the hot clean purified gas stream having a temperature of at least 1000 F. 1 figure.
Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA
2012-05-15
A gas separation process for treating exhaust gases from the combustion of gaseous fuels, and gaseous fuel combustion processes including such gas separation. The invention involves routing a first portion of the exhaust stream to a carbon dioxide capture step, while simultaneously flowing a second portion of the exhaust gas stream across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas back to the combustor.
Integrated coke, asphalt and jet fuel production process and apparatus
Shang, Jer Y.
1991-01-01
A process and apparatus for the production of coke, asphalt and jet fuel m a feed of fossil fuels containing volatile carbon compounds therein is disclosed. The process includes the steps of pyrolyzing the feed in an entrained bed pyrolyzing means, separating the volatile pyrolysis products from the solid pyrolysis products removing at least one coke from the solid pyrolysis products, fractionating the volatile pyrolysis products to produce an overhead stream and a bottom stream which is useful as asphalt for road pavement, condensing the overhead stream to produce a condensed liquid fraction and a noncondensable, gaseous fraction, and removing water from the condensed liquid fraction to produce a jet fuel-containing product. The disclosed apparatus is useful for practicing the foregoing process. the process provides a useful method of mass producing and jet fuels from materials such as coal, oil shale and tar sands.
Preventing CO poisoning in fuel cells
Gottesfeld, Shimshon
1990-01-01
Proton exchange membrane (PEM) fuel cell performance with CO contamination of the H.sub.2 fuel stream is substantially improved by injecting O.sub.2 into the fuel stream ahead of the fuel cell. It is found that a surface reaction occurs even at PEM operating temperatures below about 100.degree. C. to oxidatively remove the CO and restore electrode surface area for the H.sub.2 reaction to generate current. Using an O.sub.2 injection, a suitable fuel stream for a PEM fuel cell can be formed from a methanol source using conventional reforming processes for producing H.sub.2.
Method for removing acid gases from a gaseous stream
Gorin, Everett; Zielke, Clyde W.
1981-01-01
In a process for hydrocracking a heavy aromatic polynuclear carbonaceous feedstock containing reactive alkaline constituents to produce liquid hydrocarbon fuels boiling below about 475.degree. C. at atmospheric pressure by contacting the feedstock with hydrogen in the presence of a molten metal halide catalyst, thereafter separating a gaseous stream containing hydrogen, at least a portion of the hydrocarbon fuels and acid gases from the molten metal halide and regenerating the molten metal halide, thereby producing a purified molten metal halide stream for recycle to the hydrocracking zone, an improvement comprising; contacting the gaseous acid gas, hydrogen and hydrocarbon fuels-containing stream with the feedstock containing reactive alkaline constituents to remove acid gases from the acid gas containing stream. Optionally at least a portion of the hydrocarbon fuels are separated from gaseous stream containing hydrogen, hydrocarbon fuels and acid gases prior to contacting the gaseous stream with the feedstock.
Method for converting hydrocarbon fuel into hydrogen gas and carbon dioxide
Clawson, Lawrence G.; Mitchell, William L.; Bentley, Jeffrey M.; Thijssen, Johannes H. J.
2000-01-01
A method for converting hydrocarbon fuel into hydrogen gas and carbon dioxide within a reformer 10 is disclosed. According to the method, a stream including an oxygen-containing gas is directed adjacent to a first vessel 18 and the oxygen-containing gas is heated. A stream including unburned fuel is introduced into the oxygen-containing gas stream to form a mixture including oxygen-containing gas and fuel. The mixture of oxygen-containing gas and unburned fuel is directed tangentially into a partial oxidation reaction zone 24 within the first vessel 18. The mixture of oxygen-containing gas and fuel is further directed through the partial oxidation reaction zone 24 to produce a heated reformate stream including hydrogen gas and carbon monoxide. Steam may also be mixed with the oxygen-containing gas and fuel, and the reformate stream from the partial oxidation reaction zone 24 directed into a steam reforming zone 26. High- and low-temperature shift reaction zones 64,76 may be employed for further fuel processing.
Low NO[sub x], cogeneration process and system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bell, R.D.
1993-07-06
A process is described for low NO[sub x] cogeneration to produce electricity and useful heat, which comprises: providing fuel and oxygen to an internal combustion engine connected to drive an electric generator, to thereby generate electricity; recovering from said engine an exhaust stream including elevated NO[sub x] levels and combined oxygen; adding to said exhaust stream sufficient fuel to create a fuel-rich mixture, the quantity of fuel being sufficient to react with the available oxygen and reduce the NO[sub x], in said exhaust stream; providing said fuel-enriched exhaust stream to a thermal reactor and reacting therein said fuel, NO[sub x]more » and available oxygen, to provide a heated oxygen-depleted stream; cooling said oxygen-depleted stream by passing same through a first heat exchanger; adding conversion oxygen to said cooled stream from said heat exchanger, and passing the cooled oxygen-augmented stream over a first catalyst bed operated at a temperature of about 750 to 1,250 F under overall reducing conditions, the quantity of conversion oxygen added being in stoichiometric excess of the amount of NO[sub x], but less than the amount of combustibles; whereby the NO[sub x] is first oxidized to NO[sub 2], and then the NO[sub 2] is reduced by the excess combustibles; cooling said stream from said first catalyst bed to a temperature of about 450 to 650 F by passing said stream through a second heat exchanger; adding air to the resulting cooled stream to produce a further cooled stream at a temperature of about 400 to 600 F, and having a stoichiometric excess of oxygen; and passing said stream having said stoichiometric excess of oxygen over an oxidizing catalyst bed at said temperature of 400 to 600 F to oxidize remaining excess combustibles, to thereby provide an effluent stream having environmentally safe characteristics.« less
Methods of producing transportation fuel
Nair, Vijay [Katy, TX; Roes, Augustinus Wilhelmus Maria [Houston, TX; Cherrillo, Ralph Anthony [Houston, TX; Bauldreay, Joanna M [Chester, GB
2011-12-27
Systems, methods, and heaters for treating a subsurface formation are described herein. At least one method for producing transportation fuel is described herein. The method for producing transportation fuel may include providing formation fluid having a boiling range distribution between -5.degree. C. and 350.degree. C. from a subsurface in situ heat treatment process to a subsurface treatment facility. A liquid stream may be separated from the formation fluid. The separated liquid stream may be hydrotreated and then distilled to produce a distilled stream having a boiling range distribution between 150.degree. C. and 350.degree. C. The distilled liquid stream may be combined with one or more additives to produce transportation fuel.
Hydrogen Generation Via Fuel Reforming
NASA Astrophysics Data System (ADS)
Krebs, John F.
2003-07-01
Reforming is the conversion of a hydrocarbon based fuel to a gas mixture that contains hydrogen. The H2 that is produced by reforming can then be used to produce electricity via fuel cells. The realization of H2-based power generation, via reforming, is facilitated by the existence of the liquid fuel and natural gas distribution infrastructures. Coupling these same infrastructures with more portable reforming technology facilitates the realization of fuel cell powered vehicles. The reformer is the first component in a fuel processor. Contaminants in the H2-enriched product stream, such as carbon monoxide (CO) and hydrogen sulfide (H2S), can significantly degrade the performance of current polymer electrolyte membrane fuel cells (PEMFC's). Removal of such contaminants requires extensive processing of the H2-rich product stream prior to utilization by the fuel cell to generate electricity. The remaining components of the fuel processor remove the contaminants in the H2 product stream. For transportation applications the entire fuel processing system must be as small and lightweight as possible to achieve desirable performance requirements. Current efforts at Argonne National Laboratory are focused on catalyst development and reactor engineering of the autothermal processing train for transportation applications.
Marker, Terry L; Felix, Larry G; Linck, Martin B; Roberts, Michael J
2014-09-23
This invention relates to a process for thermochemically transforming biomass or other oxygenated feedstocks into high quality liquid hydrocarbon fuels. In particular, a catalytic hydropyrolysis reactor, containing a deep bed of fluidized catalyst particles is utilized to accept particles of biomass or other oxygenated feedstocks that are significantly smaller than the particles of catalyst in the fluidized bed. The reactor features an insert or other structure disposed within the reactor vessel that inhibits slugging of the bed and thereby minimizes attrition of the catalyst. Within the bed, the biomass feedstock is converted into a vapor-phase product, containing hydrocarbon molecules and other process vapors, and an entrained solid char product, which is separated from the vapor stream after the vapor stream has been exhausted from the top of the reactor. When the product vapor stream is cooled to ambient temperatures, a significant proportion of the hydrocarbons in the product vapor stream can be recovered as a liquid stream of hydrophobic hydrocarbons, with properties consistent with those of gasoline, kerosene, and diesel fuel. Separate streams of gasoline, kerosene, and diesel fuel may also be obtained, either via selective condensation of each type of fuel, or via later distillation of the combined hydrocarbon liquid.
Marker, Terry L.; Felix, Larry G.; Linck, Martin B.; Roberts, Michael J.
2016-12-06
This invention relates to a process for thermochemically transforming biomass or other oxygenated feedstocks into high quality liquid hydrocarbon fuels. In particular, a catalytic hydropyrolysis reactor, containing a deep bed of fluidized catalyst particles is utilized to accept particles of biomass or other oxygenated feedstocks that are significantly smaller than the particles of catalyst in the fluidized bed. The reactor features an insert or other structure disposed within the reactor vessel that inhibits slugging of the bed and thereby minimizes attrition of the catalyst. Within the bed, the biomass feedstock is converted into a vapor-phase product, containing hydrocarbon molecules and other process vapors, and an entrained solid char product, which is separated from the vapor stream after the vapor stream has been exhausted from the top of the reactor. When the product vapor stream is cooled to ambient temperatures, a significant proportion of the hydrocarbons in the product vapor stream can be recovered as a liquid stream of hydrophobic hydrocarbons, with properties consistent with those of gasoline, kerosene, and diesel fuel. Separate streams of gasoline, kerosene, and diesel fuel may also be obtained, either via selective condensation of each type of fuel, or via later distillation of the combined hydrocarbon liquid.
Two-stage coal gasification and desulfurization apparatus
Bissett, Larry A.; Strickland, Larry D.
1991-01-01
The present invention is directed to a system which effectively integrates a two-stage, fixed-bed coal gasification arrangement with hot fuel gas desulfurization of a first stream of fuel gas from a lower stage of the two-stage gasifier and the removal of sulfur from the sulfur sorbent regeneration gas utilized in the fuel-gas desulfurization process by burning a second stream of fuel gas from the upper stage of the gasifier in a combustion device in the presence of calcium-containing material. The second stream of fuel gas is taken from above the fixed bed in the coal gasifier and is laden with ammonia, tar and sulfur values. This second stream of fuel gas is burned in the presence of excess air to provide heat energy sufficient to effect a calcium-sulfur compound forming reaction between the calcium-containing material and sulfur values carried by the regeneration gas and the second stream of fuel gas. Any ammonia values present in the fuel gas are decomposed during the combustion of the fuel gas in the combustion chamber. The substantially sulfur-free products of combustion may then be combined with the desulfurized fuel gas for providing a combustible fluid utilized for driving a prime mover.
Separation of uranium from technetium in recovery of spent nuclear fuel
Pruett, D.J.; McTaggart, D.R.
1983-08-31
Uranium and technetium in the product stream of the Purex process for recovery of uranium in spent nuclear fuel are separated by (1) contacting the aqueous Purex product stream with hydrazine to reduce Tc/sup +7/ therein to a reduced species, and (2) contacting said aqueous stream with an organic phase containing tributyl phosphate and an organic diluent to extract uranium from said aqueous stream into said organic phase.
Separation of uranium from technetium in recovery of spent nuclear fuel
Pruett, David J.; McTaggart, Donald R.
1984-01-01
Uranium and technetium in the product stream of the Purex process for recovery of uranium in spent nuclear fuel are separated by (1) contacting the aqueous Purex product stream with hydrazine to reduce Tc.sup.+7 therein to a reduced species, and (2) contacting said aqueous stream with an organic phase containing tributyl phosphate and an organic diluent to extract uranium from said aqueous stream into said organic phase.
Reforming of fuel inside fuel cell generator
Grimble, Ralph E.
1988-01-01
Disclosed is an improved method of reforming a gaseous reformable fuel within a solid oxide fuel cell generator, wherein the solid oxide fuel cell generator has a plurality of individual fuel cells in a refractory container, the fuel cells generating a partially spent fuel stream and a partially spent oxidant stream. The partially spent fuel stream is divided into two streams, spent fuel stream I and spent fuel stream II. Spent fuel stream I is burned with the partially spent oxidant stream inside the refractory container to produce an exhaust stream. The exhaust stream is divided into two streams, exhaust stream I and exhaust stream II, and exhaust stream I is vented. Exhaust stream II is mixed with spent fuel stream II to form a recycle stream. The recycle stream is mixed with the gaseous reformable fuel within the refractory container to form a fuel stream which is supplied to the fuel cells. Also disclosed is an improved apparatus which permits the reforming of a reformable gaseous fuel within such a solid oxide fuel cell generator. The apparatus comprises a mixing chamber within the refractory container, means for diverting a portion of the partially spent fuel stream to the mixing chamber, means for diverting a portion of exhaust gas to the mixing chamber where it is mixed with the portion of the partially spent fuel stream to form a recycle stream, means for injecting the reformable gaseous fuel into the recycle stream, and means for circulating the recycle stream back to the fuel cells.
Reforming of fuel inside fuel cell generator
Grimble, R.E.
1988-03-08
Disclosed is an improved method of reforming a gaseous reformable fuel within a solid oxide fuel cell generator, wherein the solid oxide fuel cell generator has a plurality of individual fuel cells in a refractory container, the fuel cells generating a partially spent fuel stream and a partially spent oxidant stream. The partially spent fuel stream is divided into two streams, spent fuel stream 1 and spent fuel stream 2. Spent fuel stream 1 is burned with the partially spent oxidant stream inside the refractory container to produce an exhaust stream. The exhaust stream is divided into two streams, exhaust stream 1 and exhaust stream 2, and exhaust stream 1 is vented. Exhaust stream 2 is mixed with spent fuel stream 2 to form a recycle stream. The recycle stream is mixed with the gaseous reformable fuel within the refractory container to form a fuel stream which is supplied to the fuel cells. Also disclosed is an improved apparatus which permits the reforming of a reformable gaseous fuel within such a solid oxide fuel cell generator. The apparatus comprises a mixing chamber within the refractory container, means for diverting a portion of the partially spent fuel stream to the mixing chamber, means for diverting a portion of exhaust gas to the mixing chamber where it is mixed with the portion of the partially spent fuel stream to form a recycle stream, means for injecting the reformable gaseous fuel into the recycle stream, and means for circulating the recycle stream back to the fuel cells. 1 fig.
Methods of making transportation fuel
Roes, Augustinus Wilhelmus Maria [Houston, TX; Mo, Weijian [Sugar Land, TX; Muylle, Michel Serge Marie [Houston, TX; Mandema, Remco Hugo [Houston, TX; Nair, Vijay [Katy, TX
2012-04-10
A method for producing alkylated hydrocarbons is disclosed. Formation fluid is produced from a subsurface in situ heat treatment process. The formation fluid is separated to produce a liquid stream and a first gas stream. The first gas stream includes olefins. The liquid stream is fractionated to produce at least a second gas stream including hydrocarbons having a carbon number of at least 3. The first gas stream and the second gas stream are introduced into an alkylation unit to produce alkylated hydrocarbons. At least a portion of the olefins in the first gas stream enhance alkylation. The alkylated hydrocarbons may be blended with one or more components to produce transportation fuel.
Electrochemical/Pyrometallurgical Waste Stream Processing and Waste Form Fabrication
DOE Office of Scientific and Technical Information (OSTI.GOV)
Steven Frank; Hwan Seo Park; Yung Zun Cho
This report summarizes treatment and waste form options being evaluated for waste streams resulting from the electrochemical/pyrometallurgical (pyro ) processing of used oxide nuclear fuel. The technologies that are described are South Korean (Republic of Korea – ROK) and United States of America (US) ‘centric’ in the approach to treating pyroprocessing wastes and are based on the decade long collaborations between US and ROK researchers. Some of the general and advanced technologies described in this report will be demonstrated during the Integrated Recycle Test (IRT) to be conducted as a part of the Joint Fuel Cycle Study (JFCS) collaboration betweenmore » US Department of Energy (DOE) and ROK national laboratories. The JFCS means to specifically address and evaluated the technological, economic, and safe guard issues associated with the treatment of used nuclear fuel by pyroprocessing. The IRT will involve the processing of commercial, used oxide fuel to recover uranium and transuranics. The recovered transuranics will then be fabricated into metallic fuel and irradiated to transmutate, or burn the transuranic elements to shorter lived radionuclides. In addition, the various process streams will be evaluated and tested for fission product removal, electrolytic salt recycle, minimization of actinide loss to waste streams and waste form fabrication and characterization. This report specifically addresses the production and testing of those waste forms to demonstrate their compatibility with treatment options and suitability for disposal.« less
High temperature desulfurization of synthesis gas
Najjar, Mitri S.; Robin, Allen M.
1989-01-01
The hot process gas stream from the partial oxidation of sulfur-containing heavy liquid hydrocarbonaceous fuel and/or sulfur-containing solid carbonaceous fuel comprising gaseous mixtures of H.sub.2 +CO, sulfur-containing gases, entrained particulate carbon, and molten slag is passed through the unobstructed central passage of a radiant cooler where the temperature is reduced to a temperature in the range of about 1800.degree. F. to 1200.degree. F. From about 0 to 95 wt. % of the molten slag and/or entrained material may be removed from the hot process gas stream prior to the radiant cooler with substantially no reduction in temperature of the process gas stream. In the radiant cooler, after substantially all of the molten slag has solidified, the sulfur-containing gases are contacted with a calcium-containing material to produce calcium sulfide. A partially cooled stream of synthesis gas, reducing gas, or fuel gas containing entrained calcium sulfide particulate matter, particulate carbon, and solidified slag leaves the radiant cooler containing a greatly reduced amount of sulfur-containing gases.
40 CFR 65.149 - Boilers and process heaters.
Code of Federal Regulations, 2010 CFR
2010-07-01
... stream is not introduced as or with the primary fuel, a temperature monitoring device in the fire box...-throughput transfer racks, as applicable, shall meet the requirements of this section. (2) The vent stream... thermal units per hour) or greater. (ii) A boiler or process heater into which the vent stream is...
Molten salt destruction of energetic waste materials
Brummond, W.A.; Upadhye, R.S.; Pruneda, C.O.
1995-07-18
A molten salt destruction process is used to treat and destroy energetic waste materials such as high explosives, propellants, and rocket fuels. The energetic material is pre-blended with a solid or fluid diluent in safe proportions to form a fluid fuel mixture. The fuel mixture is rapidly introduced into a high temperature molten salt bath. A stream of molten salt is removed from the vessel and may be recycled as diluent. Additionally, the molten salt stream may be pumped from the reactor, circulated outside the reactor for further processing, and delivered back into the reactor or cooled and circulated to the feed delivery system to further dilute the fuel mixture entering the reactor. 4 figs.
Molten salt destruction of energetic waste materials
Brummond, William A.; Upadhye, Ravindra S.; Pruneda, Cesar O.
1995-01-01
A molten salt destruction process is used to treat and destroy energetic waste materials such as high explosives, propellants, and rocket fuels. The energetic material is pre-blended with a solid or fluid diluent in safe proportions to form a fluid fuel mixture. The fuel mixture is rapidly introduced into a high temperature molten salt bath. A stream of molten salt is removed from the vessel and may be recycled as diluent. Additionally, the molten salt stream may be pumped from the reactor, circulated outside the reactor for further processing, and delivered back into the reactor or cooled and circulated to the feed delivery system to further dilute the fuel mixture entering the reactor.
NASA Technical Reports Server (NTRS)
Hepp, Aloysius F.; Kulis, Michael J.; Psarras, Peter C.; Ball, David W.; Timko, Michael T.; Wong, Hsi-Wu; Peck, Jay; Chianelli, Russell R.
2014-01-01
Transportation fuels production (including aerospace propellants) from non-traditional sources (gases, waste materials, and biomass) has been an active area of research and development for decades. Reducing terrestrial waste streams simultaneous with energy conversion, plentiful biomass, new low-cost methane sources, and/or extra-terrestrial resource harvesting and utilization present significant technological and business opportunities being realized by a new generation of visionary entrepreneurs. We examine several new approaches to catalyst fabrication and new processing technologies to enable utilization of these nontraditional raw materials. Two basic processing architectures are considered: a single-stage pyrolysis approach that seeks to basically re-cycle hydrocarbons with minimal net chemistry or a two-step paradigm that involves production of supply or synthesis gas (mainly carbon oxides and H2) followed by production of fuel(s) via Sabatier or methanation reactions and/or Fischer-Tröpsch synthesis. Optimizing the fraction of product stream relevant to targeted aerospace (and other transportation) fuels via modeling, catalyst fabrication and novel reactor design are described. Energy utilization is a concern for production of fuels for either terrestrial or space operations; renewable sources based on solar energy and/or energy efficient processes may be mission enabling. Another important issue is minimizing impurities in the product stream(s), especially those potentially posing risks to personnel or operations through (catalyst) poisoning or (equipment) damage. Technologies being developed to remove (and/or recycle) heteroatom impurities are briefly discussed as well as the development of chemically robust catalysts whose activities are not diminished during operation. The potential impacts on future missions by such new approaches as well as balance of system issues are addressed.
NASA Technical Reports Server (NTRS)
Hepp, A. F.; Kulis, M. J.; Psarras, P. C.; Ball, D. W.; Timko, M. T.; Wong, H.-W.; Peck, J.; Chianelli, R. R.
2014-01-01
Transportation fuels production (including aerospace propellants) from non-traditional sources (gases, waste materials, and biomass) has been an active area of research and development for decades. Reducing terrestrial waste streams simultaneous with energy conversion, plentiful biomass, new low-cost methane sources, and/or extra-terrestrial resource harvesting and utilization present significant technological and business opportunities being realized by a new generation of visionary entrepreneurs. We examine several new approaches to catalyst fabrication and new processing technologies to enable utilization of these non-traditional raw materials. Two basic processing architectures are considered: a single-stage pyrolysis approach that seeks to basically re-cycle hydrocarbons with minimal net chemistry or a two-step paradigm that involves production of supply or synthesis gas (mainly carbon oxides and hydrogen) followed by production of fuel(s) via Sabatier or methanation reactions and/or Fischer-Tropsch synthesis. Optimizing the fraction of product stream relevant to targeted aerospace (and other transportation) fuels via modeling, catalyst fabrication and novel reactor design are described. Energy utilization is a concern for production of fuels for either terrestrial or space operations; renewable sources based on solar energy and/or energy efficient processes may be mission enabling. Another important issue is minimizing impurities in the product stream(s), especially those potentially posing risks to personnel or operations through (catalyst) poisoning or (equipment) damage. Technologies being developed to remove (and/or recycle) heteroatom impurities are briefly discussed as well as the development of chemically robust catalysts whose activity are not diminished during operation. The potential impacts on future missions by such new approaches as well as balance of system issues are addressed.
Partial oxidation power plant with reheating and method thereof
Newby, Richard A.; Yang, Wen-Ching; Bannister, Ronald L.
1999-01-01
A system and method for generating power having an air compression/partial oxidation system, a turbine, and a primary combustion system. The air compression/partial oxidation system receives a first air stream and a fuel stream and produces a first partially oxidized fuel stream and a first compressed air stream therefrom. The turbine expands the first partially oxidized fuel stream while being cooled by the first compressed air stream to produce a heated air stream. The heated air stream is injected into the expanding first partially oxidized fuel stream, thereby reheating it in the turbine. A second partially oxidized fuel stream is emitted from the turbine. The primary combustion system receives said second partially oxidized fuel stream and a second air stream, combusts said second partially oxidized fuel stream, and produces rotating shaft power and an emission stream therefrom.
Fossil fuel combined cycle power generation method
Labinov, Solomon D [Knoxville, TN; Armstrong, Timothy R [Clinton, TN; Judkins, Roddie R [Knoxville, TN
2008-10-21
A method for converting fuel energy to electricity includes the steps of converting a higher molecular weight gas into at least one mixed gas stream of lower average molecular weight including at least a first lower molecular weight gas and a second gas, the first and second gases being different gases, wherein the first lower molecular weight gas comprises H.sub.2 and the second gas comprises CO. The mixed gas is supplied to at least one turbine to produce electricity. The mixed gas stream is divided after the turbine into a first gas stream mainly comprising H.sub.2 and a second gas stream mainly comprising CO. The first and second gas streams are then electrochemically oxidized in separate fuel cells to produce electricity. A nuclear reactor can be used to supply at least a portion of the heat the required for the chemical conversion process.
Partial oxidation power plant with reheating and method thereof
Newby, R.A.; Yang, W.C.; Bannister, R.L.
1999-08-10
A system and method are disclosed for generating power having an air compression/partial oxidation system, a turbine, and a primary combustion system. The air compression/partial oxidation system receives a first air stream and a fuel stream and produces a first partially oxidized fuel stream and a first compressed air stream therefrom. The turbine expands the first partially oxidized fuel stream while being cooled by the first compressed air stream to produce a heated air stream. The heated air stream is injected into the expanding first partially oxidized fuel stream, thereby reheating it in the turbine. A second partially oxidized fuel stream is emitted from the turbine. The primary combustion system receives said second partially oxidized fuel stream and a second air stream, combusts said second partially oxidized fuel stream, and produces rotating shaft power and an emission stream therefrom. 2 figs.
Aqueous stream characterization from biomass fast pyrolysis and catalytic fast pyrolysis
Black, Brenna A.; Michener, William E.; Ramirez, Kelsey J.; ...
2016-09-05
Here, biomass pyrolysis offers a promising means to rapidly depolymerize lignocellulosic biomass for subsequent catalytic upgrading to renewable fuels. Substantial efforts are currently ongoing to optimize pyrolysis processes including various fast pyrolysis and catalytic fast pyrolysis schemes. In all cases, complex aqueous streams are generated containing solubilized organic compounds that are not converted to target fuels or chemicals and are often slated for wastewater treatment, in turn creating an economic burden on the biorefinery. Valorization of the species in these aqueous streams, however, offers significant potential for substantially improving the economics and sustainability of thermochemical biorefineries. To that end, heremore » we provide a thorough characterization of the aqueous streams from four pilot-scale pyrolysis processes: namely, from fast pyrolysis, fast pyrolysis with downstream fractionation, in situ catalytic fast pyrolysis, and ex situ catalytic fast pyrolysis. These configurations and processes represent characteristic pyrolysis processes undergoing intense development currently. Using a comprehensive suite of aqueous-compatible analytical techniques, we quantitatively characterize between 12 g kg -1 of organic carbon of a highly aqueous catalytic fast pyrolysis stream and up to 315 g kg -1 of organic carbon present in the fast pyrolysis aqueous streams. In all cases, the analysis ranges between 75 and 100% of mass closure. The composition and stream properties closely match the nature of pyrolysis processes, with high contents of carbohydrate-derived compounds in the fast pyrolysis aqueous phase, high acid content in nearly all streams, and mostly recalcitrant phenolics in the heavily deoxygenated ex situ catalytic fast pyrolysis stream. Overall, this work provides a detailed compositional analysis of aqueous streams from leading thermochemical processes -- analyses that are critical for subsequent development of selective valorization strategies for these waste streams.« less
Aqueous stream characterization from biomass fast pyrolysis and catalytic fast pyrolysis
DOE Office of Scientific and Technical Information (OSTI.GOV)
Black, Brenna A.; Michener, William E.; Ramirez, Kelsey J.
Here, biomass pyrolysis offers a promising means to rapidly depolymerize lignocellulosic biomass for subsequent catalytic upgrading to renewable fuels. Substantial efforts are currently ongoing to optimize pyrolysis processes including various fast pyrolysis and catalytic fast pyrolysis schemes. In all cases, complex aqueous streams are generated containing solubilized organic compounds that are not converted to target fuels or chemicals and are often slated for wastewater treatment, in turn creating an economic burden on the biorefinery. Valorization of the species in these aqueous streams, however, offers significant potential for substantially improving the economics and sustainability of thermochemical biorefineries. To that end, heremore » we provide a thorough characterization of the aqueous streams from four pilot-scale pyrolysis processes: namely, from fast pyrolysis, fast pyrolysis with downstream fractionation, in situ catalytic fast pyrolysis, and ex situ catalytic fast pyrolysis. These configurations and processes represent characteristic pyrolysis processes undergoing intense development currently. Using a comprehensive suite of aqueous-compatible analytical techniques, we quantitatively characterize between 12 g kg -1 of organic carbon of a highly aqueous catalytic fast pyrolysis stream and up to 315 g kg -1 of organic carbon present in the fast pyrolysis aqueous streams. In all cases, the analysis ranges between 75 and 100% of mass closure. The composition and stream properties closely match the nature of pyrolysis processes, with high contents of carbohydrate-derived compounds in the fast pyrolysis aqueous phase, high acid content in nearly all streams, and mostly recalcitrant phenolics in the heavily deoxygenated ex situ catalytic fast pyrolysis stream. Overall, this work provides a detailed compositional analysis of aqueous streams from leading thermochemical processes -- analyses that are critical for subsequent development of selective valorization strategies for these waste streams.« less
Solid oxide fuel cell process and apparatus
Cooper, Matthew Ellis [Morgantown, WV; Bayless, David J [Athens, OH; Trembly, Jason P [Durham, NC
2011-11-15
Conveying gas containing sulfur through a sulfur tolerant planar solid oxide fuel cell (PSOFC) stack for sulfur scrubbing, followed by conveying the gas through a non-sulfur tolerant PSOFC stack. The sulfur tolerant PSOFC stack utilizes anode materials, such as LSV, that selectively convert H.sub.2S present in the fuel stream to other non-poisoning sulfur compounds. The remaining balance of gases remaining in the completely or near H.sub.2S-free exhaust fuel stream is then used as the fuel for the conventional PSOFC stack that is downstream of the sulfur-tolerant PSOFC. A broad range of fuels such as gasified coal, natural gas and reformed hydrocarbons are used to produce electricity.
Fuel-cell engine stream conditioning system
DuBose, Ronald Arthur
2002-01-01
A stream conditioning system for a fuel cell gas management system or fuel cell engine. The stream conditioning system manages species potential in at least one fuel cell reactant stream. A species transfer device is located in the path of at least one reactant stream of a fuel cell's inlet or outlet, which transfer device conditions that stream to improve the efficiency of the fuel cell. The species transfer device incorporates an exchange media and a sorbent. The fuel cell gas management system can include a cathode loop with the stream conditioning system transferring latent and sensible heat from an exhaust stream to the cathode inlet stream of the fuel cell; an anode humidity retention system for maintaining the total enthalpy of the anode stream exiting the fuel cell related to the total enthalpy of the anode inlet stream; and a cooling water management system having segregated deionized water and cooling water loops interconnected by means of a brazed plate heat exchanger.
Method for operating a combustor in a fuel cell system
Chalfant, Robert W.; Clingerman, Bruce J.
2002-01-01
A method of operating a combustor to heat a fuel processor in a fuel cell system, in which the fuel processor generates a hydrogen-rich stream a portion of which is consumed in a fuel cell stack and a portion of which is discharged from the fuel cell stack and supplied to the combustor, and wherein first and second streams are supplied to the combustor, the first stream being a hydrocarbon fuel stream and the second stream consisting of said hydrogen-rich stream, the method comprising the steps of monitoring the temperature of the fuel processor; regulating the quantity of the first stream to the combustor according to the temperature of the fuel processor; and comparing said quantity of said first stream to a predetermined value or range of predetermined values.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stubbins, James
2012-12-19
The objective of this research program is to address major nuclear fuels performance issues for the design and use of oxide-type fuels in the current and advanced nuclear reactor applications. Fuel performance is a major issue for extending fuel burn-up which has the added advantage of reducing the used fuel waste stream. It will also be a significant issue with respect to developing advanced fuel cycle processes where it may be possible to incorporate minor actinides in various fuel forms so that they can be 'burned' rather than join the used fuel waste stream. The potential to fission or transmutemore » minor actinides and certain long-lived fission product isotopes would transform the high level waste storage strategy by removing the need to consider fuel storage on the millennium time scale.« less
Methanol tailgas combustor control method
Hart-Predmore, David J.; Pettit, William H.
2002-01-01
A method for controlling the power and temperature and fuel source of a combustor in a fuel cell apparatus to supply heat to a fuel processor where the combustor has dual fuel inlet streams including a first fuel stream, and a second fuel stream of anode effluent from the fuel cell and reformate from the fuel processor. In all operating modes, an enthalpy balance is determined by regulating the amount of the first and/or second fuel streams and the quantity of the first air flow stream to support fuel processor power requirements.
40 CFR 62.15410 - What definitions must I know?
Code of Federal Regulations, 2014 CFR
2014-07-01
... period during which the municipal waste combustion unit combusts fossil fuel or other solid waste fuel... combusts municipal solid waste with nonmunicipal solid waste fuel (for example, coal, industrial process... permit that limits it to combusting a fuel feed stream which is 30 percent or less (by weight) municipal...
Kansa, Edward J.; Anderson, Brian L.; Wijesinghe, Ananda M.; Viani, Brian E.
1999-01-01
This invention provides a process to tremendously reduce the bulk volume of contaminants obtained from an effluent stream produced subsurface remediation. The chemicals used for the subsurface remediation are reclaimed for recycling to the remediation process. Additional reductions in contaminant bulk volume are achieved by the ultra-violet light destruction of halogenated hydrocarbons, and the complete oxidation of hydrophobic fuel hydrocarbons and hydrophilic hydrocarbons. The contaminated bulk volume will arise primarily from the disposal of the toxic metal ions. The entire process is modular, so if there are any technological breakthroughs in one or more of the component process modules, such modules can be readily replaced.
Fluidized-Solid-Fuel Injection Process
NASA Technical Reports Server (NTRS)
Taylor, William
1992-01-01
Report proposes development of rocket engines burning small grains of solid fuel entrained in gas streams. Main technical discussion in report divided into three parts: established fluidization technology; variety of rockets and rocket engines used by nations around the world; and rocket-engine equation. Discusses significance of specific impulse and ratio between initial and final masses of rocket. Concludes by stating three important reasons to proceed with new development: proposed engines safer; fluidized-solid-fuel injection process increases variety of solid-fuel formulations used; and development of fluidized-solid-fuel injection process provides base of engineering knowledge.
Survey of advanced nuclear technologies for potential applications of sonoprocessing.
Rubio, Floren; Blandford, Edward D; Bond, Leonard J
2016-09-01
Ultrasonics has been used in many industrial applications for both sensing at low power and processing at higher power. Generally, the high power applications fall within the categories of liquid stream degassing, impurity separation, and sonochemical enhancement of chemical processes. Examples of such industrial applications include metal production, food processing, chemical production, and pharmaceutical production. There are many nuclear process streams that have similar physical and chemical processes to those applications listed above. These nuclear processes could potentially benefit from the use of high-power ultrasonics. There are also potential benefits to applying these techniques in advanced nuclear fuel cycle processes, and these benefits have not been fully investigated. Currently the dominant use of ultrasonic technology in the nuclear industry has been using low power ultrasonics for non-destructive testing/evaluation (NDT/NDE), where it is primarily used for inspections and for characterizing material degradation. Because there has been very little consideration given to how sonoprocessing can potentially improve efficiency and add value to important process streams throughout the nuclear fuel cycle, there are numerous opportunities for improvement in current and future nuclear technologies. In this paper, the relevant fundamental theory underlying sonoprocessing is highlighted, and some potential applications to advanced nuclear technologies throughout the nuclear fuel cycle are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.
Fuel quality/processing study. Volume 3: Fuel upgrading studies
NASA Technical Reports Server (NTRS)
Jones, G. E., Jr.; Bruggink, P.; Sinnett, C.
1981-01-01
The methods used to calculate the refinery selling prices for the turbine fuels of low quality are described. Detailed descriptions and economics of the upgrading schemes are included. These descriptions include flow diagrams showing the interconnection between processes and the stream flows involved. Each scheme is in a complete, integrated, stand alone facility. Except for the purchase of electricity and water, each scheme provides its own fuel and manufactures, when appropriate, its own hydrogen.
Code of Federal Regulations, 2011 CFR
2011-07-01
... an enclosed combustion device that transfers heat liberated by burning fuel directly to process streams or to heat transfer liquids other than water. A process heater may, as a secondary function, heat... means gases that are combusted to derive useful work or heat. Fuel gas system means the offsite and...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Coble, Jamie; Orton, Christopher; Schwantes, Jon
Abstract—The Multi-Isotope Process (MIP) Monitor provides an efficient approach to monitoring the process conditions in used nuclear fuel reprocessing facilities to support process verification and validation. The MIP Monitor applies multivariate analysis to gamma spectroscopy of reprocessing streams in order to detect small changes in the gamma spectrum, which may indicate changes in process conditions. This research extends the MIP Monitor by characterizing a used fuel sample after initial dissolution according to the type of reactor of origin (pressurized or boiling water reactor), initial enrichment, burn up, and cooling time. Simulated gamma spectra were used to develop and test threemore » fuel characterization algorithms. The classification and estimation models employed are based on the partial least squares regression (PLS) algorithm. A PLS discriminate analysis model was developed which perfectly classified reactor type. Locally weighted PLS models were fitted on-the-fly to estimate continuous fuel characteristics. Burn up was predicted within 0.1% root mean squared percent error (RMSPE) and both cooling time and initial enrichment within approximately 2% RMSPE. This automated fuel characterization can be used to independently verify operator declarations of used fuel characteristics and inform the MIP Monitor anomaly detection routines at later stages of the fuel reprocessing stream to improve sensitivity to changes in operational parameters and material diversions.« less
WOOD PRODUCTS IN THE WASTE STREAM: CHARACTERIZATION AND COMBUSTION EMISSIONS - VOLUME 2. APPENDICES
The report gives results of a study of technical, public policy, and regulatory issues that affect the processing and combustion of waste wood for fuel. (NOTE: Waste wood is wood that is separated from a solid-waste stream, processed into a uniform-sized product, and reused for o...
The report gives results of a study of technical, public policy, and regulatory issues that affect the processing and combustion of waste wood for fuel. (NOTE: Waste wood is wood that is separated from a solid-waste stream, processed into a uniform-sized product, and reused for o...
Efficient gas-separation process to upgrade dilute methane stream for use as fuel
Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Lin, Haiqing [Mountain View, CA; Thompson, Scott [Brecksville, OH; Daniels, Ramin [San Jose, CA
2012-03-06
A membrane-based gas separation process for treating gas streams that contain methane in low concentrations. The invention involves flowing the stream to be treated across the feed side of a membrane and flowing a sweep gas stream, usually air, across the permeate side. Carbon dioxide permeates the membrane preferentially and is picked up in the sweep air stream on the permeate side; oxygen permeates in the other direction and is picked up in the methane-containing stream. The resulting residue stream is enriched in methane as well as oxygen and has an EMC value enabling it to be either flared or combusted by mixing with ordinary air.
Mixing enhancement of reacting parallel fuel jets in a supersonic combustor
NASA Technical Reports Server (NTRS)
Drummond, J. P.
1991-01-01
Pursuant to a NASA-Langley development program for a scramjet HST propulsion system entailing the optimization of the scramjet combustor's fuel-air mixing and reaction characteristics, a numerical study has been conducted of the candidate parallel fuel injectors. Attention is given to a method for flow mixing-process and combustion-efficiency enhancement in which a supersonic circular hydrogen jet coflows with a supersonic air stream. When enhanced by a planar oblique shock, the injector configuration exhibited a substantial degree of induced vorticity in the fuel stream which increased mixing and chemical reaction rates, relative to the unshocked configuration. The resulting heat release was effective in breaking down the stable hydrogen vortex pair that had inhibited more extensive fuel-air mixing.
Kansa, E.J.; Anderson, B.L.; Wijesinghe, A.M.; Viani, B.E.
1999-05-25
This invention provides a process to tremendously reduce the bulk volume of contaminants obtained from an effluent stream produced subsurface remediation. The chemicals used for the subsurface remediation are reclaimed for recycling to the remediation process. Additional reductions in contaminant bulk volume are achieved by the ultra-violet light destruction of halogenated hydrocarbons, and the complete oxidation of hydrophobic fuel hydrocarbons and hydrophilic hydrocarbons. The contaminated bulk volume will arise primarily from the disposal of the toxic metal ions. The entire process is modular, so if there are any technological breakthroughs in one or more of the component process modules, such modules can be readily replaced. 3 figs.
Integrated capture of fossil fuel gas pollutants including CO.sub.2 with energy recovery
Ochs, Thomas L [Albany, OR; Summers, Cathy A [Albany, OR; Gerdemann, Steve [Albany, OR; Oryshchyn, Danylo B [Philomath, OR; Turner, Paul [Independence, OR; Patrick, Brian R [Chicago, IL
2011-10-18
A method of reducing pollutants exhausted into the atmosphere from the combustion of fossil fuels. The disclosed process removes nitrogen from air for combustion, separates the solid combustion products from the gases and vapors and can capture the entire vapor/gas stream for sequestration leaving near-zero emissions. The invention produces up to three captured material streams. The first stream is contaminant-laden water containing SO.sub.x, residual NO.sub.x particulates and particulate-bound Hg and other trace contaminants. The second stream can be a low-volume flue gas stream containing N.sub.2 and O.sub.2 if CO2 purification is needed. The final product stream is a mixture comprising predominantly CO.sub.2 with smaller amounts of H.sub.2O, Ar, N.sub.2, O.sub.2, SO.sub.X, NO.sub.X, Hg, and other trace gases.
High temperature methods for forming oxidizer fuel
Bravo, Jose Luis [Houston, TX
2011-01-11
A method of treating a formation fluid includes providing formation fluid from a subsurface in situ heat treatment process. The formation fluid is separated to produce a liquid stream and a first gas stream. The first gas stream includes carbon dioxide, hydrogen sulfide, hydrocarbons, hydrogen or mixtures thereof. Molecular oxygen is separated from air to form a molecular oxygen stream comprising molecular oxygen. The first gas stream is combined with the molecular oxygen stream to form a combined stream comprising molecular oxygen and the first gas stream. The combined stream is provided to one or more downhole burners.
Production of distillate fuels from biomass-derived polyoxygenates
Kania, John; Blommel, Paul; Woods, Elizabeth; Dally, Brice; Lyman, Warren; Cortright, Randy
2017-03-14
The present invention provides methods, reactor systems and catalysts for converting biomass and biomass-derived feedstocks to C.sub.8+ hydrocarbons using heterogenous catalysts. The product stream may be separated and further processed for use in chemical applications, or as a neat fuel or a blending component in jet fuel and diesel fuel, or as heavy oils for lubricant and/or fuel oil applications.
26 CFR 48.4081-1 - Taxable fuel; definitions.
Code of Federal Regulations, 2010 CFR
2010-04-01
... rare use as a fuel in the propulsion engine of a diesel-powered highway vehicle or diesel-powered train... hydrocarbon stream that is produced in a natural gas processing plant is not a gasoline blendstock if the...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Resasco, Daniel; Lobban, Lance; Crossley, Steven
The goal was to develop a biomass conversion process that optimizes fractionation and conversion to maximize Carbon efficiency and Hydrogen consumption to obtain drop-in fuels. Selective fractionation of raw biomass was obtained via multi-stage thermal fractionation to produce different streams that are enriched in a particular chemical family (acids, furanics or phenolics). These streams were later catalytically upgraded in both liquid and vapor phase to perform C-C bond formation and hydrodeoxygenation. Among various upgrading strategies investigated we have identified an effective path in which cyclopentanone is a crucial intermediate that can be derived from furfural and other furanics obtained inmore » high concentrations from this thermal staged process. Cyclopentanone is a very versatile molecule, which can couple with itself to product high quality jet-fuel, or couple with phenolic or furanics to create long chain molecules. These (mono-oxygenated) compounds in the correct molecular weight fuel range can be hydrotreated to direct drop-in fuels. Interestingly, we have found that the conversion of furfural to cyclopentanone is not affected by the presence of acetic acid, and, more interestingly, it is enhanced by the presence of water. These are very significant findings, since water and acetic acid are always present in all streams from the primary conversion stage. These results have allowed to complete detailed life-cycle assessment and techno-economic analysis that have been back-fed to the experimentalists to refine the catalyst selection and process operations with the objective of maximizing C efficiency at minimum H utilization. These combined investigations have opened the possibility of an economically and technologically effective process that could result in commercial fuels produced from renewable sources at a cost that might be competitive with fossil fuels.« less
Controlled temperature expansion in oxygen production by molten alkali metal salts
Erickson, Donald C.
1985-06-04
A continuous process is set forth for the production of oxygen from an oxygen containing gas stream, such as air, by contacting a feed gas stream with a molten solution of an oxygen acceptor to oxidize the acceptor and cyclically regenerating the oxidized acceptor by releasing oxygen from the acceptor wherein the oxygen-depleted gas stream from the contact zone is treated sequentially to temperature reduction by heat exchange against the feed stream so as to condense out entrained oxygen acceptor for recycle to the process, combustion of the gas stream with fuel to elevate its temperature and expansion of the combusted high temperature gas stream in a turbine to recover power.
Controlled temperature expansion in oxygen production by molten alkali metal salts
Erickson, D.C.
1985-06-04
A continuous process is set forth for the production of oxygen from an oxygen containing gas stream, such as air, by contacting a feed gas stream with a molten solution of an oxygen acceptor to oxidize the acceptor and cyclically regenerating the oxidized acceptor by releasing oxygen from the acceptor wherein the oxygen-depleted gas stream from the contact zone is treated sequentially to temperature reduction by heat exchange against the feed stream so as to condense out entrained oxygen acceptor for recycle to the process, combustion of the gas stream with fuel to elevate its temperature and expansion of the combusted high temperature gas stream in a turbine to recover power. 1 fig.
Method for high temperature mercury capture from gas streams
Granite, Evan J [Wexford, PA; Pennline, Henry W [Bethel Park, PA
2006-04-25
A process to facilitate mercury extraction from high temperature flue/fuel gas via the use of metal sorbents which capture mercury at ambient and high temperatures. The spent sorbents can be regenerated after exposure to mercury. The metal sorbents can be used as pure metals (or combinations of metals) or dispersed on an inert support to increase surface area per gram of metal sorbent. Iridium and ruthenium are effective for mercury removal from flue and smelter gases. Palladium and platinum are effective for mercury removal from fuel gas (syngas). An iridium-platinum alloy is suitable for metal capture in many industrial effluent gas streams including highly corrosive gas streams.
System for adding sulfur to a fuel cell stack system for improved fuel cell stability
Mukerjee, Subhasish [Pittsford, NY; Haltiner, Jr., Karl J; Weissman, Jeffrey G [West Henrietta, NY
2012-03-06
A system for adding sulfur to a fuel cell stack, having a reformer adapted to reform a hydrocarbon fuel stream containing sulfur contaminants, thereby providing a reformate stream having sulfur; a sulfur trap fluidly coupled downstream of the reformer for removing sulfur from the reformate stream, thereby providing a desulfurized reformate stream; and a metering device in fluid communication with the reformate stream upstream of the sulfur trap and with the desulfurized reformate stream downstream of the sulfur trap. The metering device is adapted to bypass a portion of the reformate stream to mix with the desulfurized reformate stream, thereby producing a conditioned reformate stream having a predetermined sulfur concentration that gives an acceptable balance of minimal drop in initial power with the desired maximum stability of operation over prolonged periods for the fuel cell stack.
Fuel processor and method for generating hydrogen for fuel cells
Ahmed, Shabbir [Naperville, IL; Lee, Sheldon H. D. [Willowbrook, IL; Carter, John David [Bolingbrook, IL; Krumpelt, Michael [Naperville, IL; Myers, Deborah J [Lisle, IL
2009-07-21
A method of producing a H.sub.2 rich gas stream includes supplying an O.sub.2 rich gas, steam, and fuel to an inner reforming zone of a fuel processor that includes a partial oxidation catalyst and a steam reforming catalyst or a combined partial oxidation and stream reforming catalyst. The method also includes contacting the O.sub.2 rich gas, steam, and fuel with the partial oxidation catalyst and the steam reforming catalyst or the combined partial oxidation and stream reforming catalyst in the inner reforming zone to generate a hot reformate stream. The method still further includes cooling the hot reformate stream in a cooling zone to produce a cooled reformate stream. Additionally, the method includes removing sulfur-containing compounds from the cooled reformate stream by contacting the cooled reformate stream with a sulfur removal agent. The method still further includes contacting the cooled reformate stream with a catalyst that converts water and carbon monoxide to carbon dioxide and H.sub.2 in a water-gas-shift zone to produce a final reformate stream in the fuel processor.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vienna, John D.; Todd, Terry A.; Gray, Kimberly D.
The U.S. Department of Energy, Office of Nuclear Energy has chartered an effort to develop technologies to enable safe and cost effective recycle of commercial used nuclear fuel (UNF) in the U.S. Part of this effort includes the evaluation of exiting waste management technologies for effective treatment of wastes in the context of current U.S. regulations and development of waste forms and processes with significant cost and/or performance benefits over those existing. This study summarizes the results of these ongoing efforts with a focus on the highly radioactive primary waste streams. The primary streams considered and the recommended waste formsmore » include: •Tritium separated from either a low volume gas stream or a high volume water stream. The recommended waste form is low-water cement in high integrity containers. •Iodine-129 separated from off-gas streams in aqueous processing. There are a range of potentially suitable waste forms. As a reference case, a glass composite material (GCM) formed by the encapsulation of the silver Mordenite (AgZ) getter material in a low-temperature glass is assumed. A number of alternatives with distinct advantages are also considered including a fused silica waste form with encapsulated nano-sized AgI crystals. •Carbon-14 separated from LWR fuel treatment off-gases and immobilized as a CaCO3 in a cement waste form. •Krypton-85 separated from LWR and SFR fuel treatment off-gases and stored as a compressed gas. •An aqueous reprocessing high-level waste (HLW) raffinate waste which is immobilized by the vitrification process in one of three forms: a single phase borosilicate glass, a borosilicate based glass ceramic, or a multi-phased titanate ceramic [e.g., synthetic rock (Synroc)]. •An undissolved solids (UDS) fraction from aqueous reprocessing of LWR fuel that is either included in the borosilicate HLW glass or is immobilized in the form of a metal alloy in the case of glass ceramics or titanate ceramics. •Zirconium-based LWR fuel cladding hulls and stainless steel (SS) fuel assembly hardware that are washed and super-compacted for disposal or as an alternative Zr purification and reuse (or disposal as low-level waste, LLW) by reactive gas separations. •Electrochemical process salt HLW which is immobilized in a glass bonded Sodalite waste form known as the ceramic waste form (CWF). •Electrochemical process UDS and SS cladding hulls which are melted into an iron based alloy waste form. Mass and volume estimates for each of the recommended waste forms based on the source terms from a representative flowsheet are reported.« less
System for adding sulfur to a fuel cell stack system for improved fuel cell stability
Mukerjee, Subhasish; Haltiner, Jr., Karl J; Weissman, Jeffrey G
2013-08-13
A system for adding sulfur to a reformate stream feeding a fuel cell stack, having a sulfur source for providing sulfur to the reformate stream and a metering device in fluid connection with the sulfur source and the reformate stream. The metering device injects sulfur from the sulfur source to the reformate stream at a predetermined rate, thereby providing a conditioned reformate stream to the fuel cell stack. The system provides a conditioned reformate stream having a predetermined sulfur concentration that gives an acceptable balance of minimal drop in initial power with the desired maximum stability of operation over prolonged periods for the fuel cell stack.
Vortex combustor for low NOX emissions when burning lean premixed high hydrogen content fuel
Steele, Robert C; Edmonds, Ryan G; Williams, Joseph T; Baldwin, Stephen P
2012-11-20
A trapped vortex combustor. The trapped vortex combustor is configured for receiving a lean premixed gaseous fuel and oxidant stream, where the fuel includes hydrogen gas. The trapped vortex combustor is configured to receive the lean premixed fuel and oxidant stream at a velocity which significantly exceeds combustion flame speed in a selected lean premixed fuel and oxidant mixture. The combustor is configured to operate at relatively high bulk fluid velocities while maintaining stable combustion, and low NOx emissions. The combustor is useful in gas turbines in a process of burning synfuels, as it offers the opportunity to avoid use of diluent gas to reduce combustion temperatures. The combustor also offers the possibility of avoiding the use of selected catalytic reaction units for removal of oxides of nitrogen from combustion gases exiting a gas turbine.
Vortex combustor for low NOx emissions when burning lean premixed high hydrogen content fuel
Steele, Robert C [Woodinville, WA; Edmonds, Ryan G [Renton, WA; Williams, Joseph T [Kirkland, WA; Baldwin, Stephen P [Winchester, MA
2009-10-20
A trapped vortex combustor. The trapped vortex combustor is configured for receiving a lean premixed gaseous fuel and oxidant stream, where the fuel includes hydrogen gas. The trapped vortex combustor is configured to receive the lean premixed fuel and oxidant stream at a velocity which significantly exceeds combustion flame speed in a selected lean premixed fuel and oxidant mixture. The combustor is configured to operate at relatively high bulk fluid velocities while maintaining stable combustion, and low NOx emissions. The combustor is useful in gas turbines in a process of burning synfuels, as it offers the opportunity to avoid use of diluent gas to reduce combustion temperatures. The combustor also offers the possibility of avoiding the use of selected catalytic reaction units for removal of oxides of nitrogen from combustion gases exiting a gas turbine.
Dissolution of used nuclear fuel using recycled nitric acid
DOE Office of Scientific and Technical Information (OSTI.GOV)
Almond, Philip M.; Daniel, Jr., William E.; Rudisill, Tracy S.
An evaluation was performed on the feasibility of using HB-Line anion exchange column waste streams from Alternate Feedstock 2 (AFS-2) processing for the dissolver solution for used nuclear fuel (UNF) processing. The targeted UNF for dissolution using recycled solution are fuels similar to the University of Missouri Research Reactor (MURR) fuel. Furthermore, the objectives of this experimental program were to validate the feasibility of using impure dissolver solutions with the MURR dissolution flowsheet to verify they would not significantly affect dissolution of the UNF in a detrimental manner.
Dissolution of used nuclear fuel using recycled nitric acid
Almond, Philip M.; Daniel, Jr., William E.; Rudisill, Tracy S.
2017-03-20
An evaluation was performed on the feasibility of using HB-Line anion exchange column waste streams from Alternate Feedstock 2 (AFS-2) processing for the dissolver solution for used nuclear fuel (UNF) processing. The targeted UNF for dissolution using recycled solution are fuels similar to the University of Missouri Research Reactor (MURR) fuel. Furthermore, the objectives of this experimental program were to validate the feasibility of using impure dissolver solutions with the MURR dissolution flowsheet to verify they would not significantly affect dissolution of the UNF in a detrimental manner.
Micro-tubular flame-assisted fuel cells for micro-combined heat and power systems
NASA Astrophysics Data System (ADS)
Milcarek, Ryan J.; Wang, Kang; Falkenstein-Smith, Ryan L.; Ahn, Jeongmin
2016-02-01
Currently the role of fuel cells in future power generation is being examined, tested and discussed. However, implementing systems is more difficult because of sealing challenges, slow start-up and complex thermal management and fuel processing. A novel furnace system with a flame-assisted fuel cell is proposed that combines the thermal management and fuel processing systems by utilizing fuel-rich combustion. In addition, the flame-assisted fuel cell furnace is a micro-combined heat and power system, which can produce electricity for homes or businesses, providing resilience during power disruption while still providing heat. A micro-tubular solid oxide fuel cell achieves a significant performance of 430 mW cm-2 operating in a model fuel-rich exhaust stream.
NOx reduction in combustion with concentrated coal streams and oxygen injection
Kobayashi, Hisashi; Bool, III, Lawrence E.; Snyder, William J.
2004-03-02
NOx formation in the combustion of solid hydrocarbonaceous fuel such as coal is reduced by obtaining, from the incoming feed stream of fuel solids and air, a stream having a ratio of fuel solids to air that is higher than that of the feed steam, and injecting the thus obtained stream and a small amount of oxygen to a burner where the fuel solids are combusted.
Environmental impact of incineration of calorific industrial waste: rotary kiln vs. cement kiln.
Vermeulen, Isabel; Van Caneghem, Jo; Block, Chantal; Dewulf, Wim; Vandecasteele, Carlo
2012-10-01
Rotary kiln incinerators and cement kilns are two energy intensive processes, requiring high temperatures that can be obtained by the combustion of fossil fuel. In both processes, fossil fuel is often substituted by high or medium calorific waste to avoid resource depletion and to save costs. Two types of industrial calorific waste streams are considered: automotive shredder residue (ASR) and meat and bone meal (MBM). These waste streams are of current high interest: ASR must be diverted from landfill, while MBM can no longer be used for cattle feeding. The environmental impact of the incineration of these waste streams is assessed and compared for both a rotary kiln and a cement kiln. For this purpose, data from an extensive emission inventory is applied for assessing the environmental impact using two different modeling approaches: one focusing on the impact of the relevant flows to and from the process and its subsystems, the other describing the change of environmental impact in response to these physical flows. Both ways of assessing emphasize different aspects of the considered processes. Attention is paid to assumptions in the methodology that can influence the outcome and conclusions of the assessment. It is concluded that for the incineration of calorific wastes, rotary kilns are generally preferred. Nevertheless, cement kilns show opportunities in improving their environmental impact when substituting their currently used fuels by more clean calorific waste streams, if this improvement is not at the expense of the actual environmental impact. Copyright © 2012 Elsevier Ltd. All rights reserved.
Energy conversion and storage program
NASA Astrophysics Data System (ADS)
Cairns, E. J.
1992-03-01
The Energy Conversion and Storage Program applies chemistry and materials science principles to solve problems in: (1) production of new synthetic fuels; (2) development of high-performance rechargeable batteries and fuel cells; (3) development of advanced thermochemical processes for energy conversion; (4) characterization of complex chemical processes; and (5) application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Topics include identification of new electrochemical couples for advanced rechargeable batteries, improvements in battery and fuel-cell materials, and the establishment of engineering principles applicable to electrochemical energy storage and conversion. Chemical Applications research includes topics such as separations, catalysis, fuels, and chemical analyses. Included in this program area are projects to develop improved, energy-efficient methods for processing waste streams from synfuel plants and coal gasifiers. Other research projects seek to identify and characterize the constituents of liquid fuel-system streams and to devise energy-efficient means for their separation. Materials Applications research includes the evaluation of the properties of advanced materials, as well as the development of novel preparation techniques. For example, the use of advanced techniques, such as sputtering and laser ablation, are being used to produce high-temperature superconducting films.
Process for vaporizing a liquid hydrocarbon fuel
Szydlowski, Donald F.; Kuzminskas, Vaidotas; Bittner, Joseph E.
1981-01-01
The object of the invention is to provide a process for vaporizing liquid hydrocarbon fuels efficiently and without the formation of carbon residue on the apparatus used. The process includes simultaneously passing the liquid fuel and an inert hot gas downwardly through a plurality of vertically spaed apart regions of high surface area packing material. The liquid thinly coats the packing surface, and the sensible heat of the hot gas vaporizes this coating of liquid. Unvaporized liquid passing through one region of packing is uniformly redistributed over the top surface of the next region until all fuel has been vaporized using only the sensible heat of the hot gas stream.
Multivariate analysis of gamma spectra to characterize used nuclear fuel
Coble, Jamie; Orton, Christopher; Schwantes, Jon
2017-01-17
The Multi-Isotope Process (MIP) Monitor provides an efficient means to monitor the process conditions in used nuclear fuel reprocessing facilities to support process verification and validation. The MIP Monitor applies multivariate analysis to gamma spectroscopy of key stages in the reprocessing stream in order to detect small changes in the gamma spectrum, which may indicate changes in process conditions. This research extends the MIP Monitor by characterizing a used fuel sample after initial dissolution according to the type of reactor of origin (pressurized or boiling water reactor; PWR and BWR, respectively), initial enrichment, burn up, and cooling time. Simulated gammamore » spectra were used in this paper to develop and test three fuel characterization algorithms. The classification and estimation models employed are based on the partial least squares regression (PLS) algorithm. A PLS discriminate analysis model was developed which perfectly classified reactor type for the three PWR and three BWR reactor designs studied. Locally weighted PLS models were fitted on-the-fly to estimate the remaining fuel characteristics. For the simulated gamma spectra considered, burn up was predicted with 0.1% root mean squared percent error (RMSPE) and both cooling time and initial enrichment with approximately 2% RMSPE. Finally, this approach to automated fuel characterization can be used to independently verify operator declarations of used fuel characteristics and to inform the MIP Monitor anomaly detection routines at later stages of the fuel reprocessing stream to improve sensitivity to changes in operational parameters that may indicate issues with operational control or malicious activities.« less
Multivariate analysis of gamma spectra to characterize used nuclear fuel
DOE Office of Scientific and Technical Information (OSTI.GOV)
Coble, Jamie; Orton, Christopher; Schwantes, Jon
The Multi-Isotope Process (MIP) Monitor provides an efficient means to monitor the process conditions in used nuclear fuel reprocessing facilities to support process verification and validation. The MIP Monitor applies multivariate analysis to gamma spectroscopy of key stages in the reprocessing stream in order to detect small changes in the gamma spectrum, which may indicate changes in process conditions. This research extends the MIP Monitor by characterizing a used fuel sample after initial dissolution according to the type of reactor of origin (pressurized or boiling water reactor; PWR and BWR, respectively), initial enrichment, burn up, and cooling time. Simulated gammamore » spectra were used in this paper to develop and test three fuel characterization algorithms. The classification and estimation models employed are based on the partial least squares regression (PLS) algorithm. A PLS discriminate analysis model was developed which perfectly classified reactor type for the three PWR and three BWR reactor designs studied. Locally weighted PLS models were fitted on-the-fly to estimate the remaining fuel characteristics. For the simulated gamma spectra considered, burn up was predicted with 0.1% root mean squared percent error (RMSPE) and both cooling time and initial enrichment with approximately 2% RMSPE. Finally, this approach to automated fuel characterization can be used to independently verify operator declarations of used fuel characteristics and to inform the MIP Monitor anomaly detection routines at later stages of the fuel reprocessing stream to improve sensitivity to changes in operational parameters that may indicate issues with operational control or malicious activities.« less
Joseph J. Bozell; Berenger Biannic; Diana Cedeno; Thomas Elder; Omid Hosseinaei; Lukas Delbeck; Jae-Woo Kim; C.J. O' Lenick; Timothy Young
2014-01-01
Abstract The concept of the integrated biorefinery is critical to developing a robust biorefining industry in the USA.Within this model, the biorefinery will produce fuel as a highvolume output addressing domestic energy needs and biobased chemical products (high-value organics) as an output providing necessary economic support for fuel production. This paper will...
Method for generating hydrogen for fuel cells
Ahmed, Shabbir; Lee, Sheldon H. D.; Carter, John David; Krumpelt, Michael
2004-03-30
A method of producing a H.sub.2 rich gas stream includes supplying an O.sub.2 rich gas, steam, and fuel to an inner reforming zone of a fuel processor that includes a partial oxidation catalyst and a steam reforming catalyst or a combined partial oxidation and stream reforming catalyst. The method also includes contacting the O.sub.2 rich gas, steam, and fuel with the partial oxidation catalyst and the steam reforming catalyst or the combined partial oxidation and stream reforming catalyst in the inner reforming zone to generate a hot reformate stream. The method still further includes cooling the hot reformate stream in a cooling zone to produce a cooled reformate stream. Additionally, the method includes removing sulfur-containing compounds from the cooled reformate stream by contacting the cooled reformate stream with a sulfur removal agent. The method still further includes contacting the cooled reformate stream with a catalyst that converts water and carbon monoxide to carbon dioxide and H.sub.2 in a water-gas-shift zone to produce a final reformate stream in the fuel processor.
Cold start characteristics of ethanol as an automobile fuel
Greiner, Leonard
1982-01-01
An alcohol fuel burner and decomposer in which one stream of fuel is preheated by passing it through an electrically heated conduit to vaporize the fuel, the fuel vapor is mixed with air, the air-fuel mixture is ignited and combusted, and the combustion gases are passed in heat exchange relationship with a conduit carrying a stream of fuel to decompose the fuel forming a fuel stream containing hydrogen gas for starting internal combustion engines, the mass flow of the combustion gas being increased as it flows in heat exchange relationship with the fuel carrying conduit, is disclosed.
Apparatus and method for burning a lean, premixed fuel/air mixture with low NOx emission
Kostiuk, Larry W.; Cheng, Robert K.
1996-01-01
An apparatus for enabling a burner to stably burn a lean fuel/air mixture. The burner directs the lean fuel/air mixture in a stream. The apparatus comprises an annular flame stabilizer; and a device for mounting the flame stabilizer in the fuel/air mixture stream. The burner may include a body having an internal bore, in which case, the annular flame stabilizer is shaped to conform to the cross-sectional shape of the bore, is spaced from the bore by a distance greater than about 0.5 mm, and the mounting device mounts the flame stabilizer in the bore. An apparatus for burning a gaseous fuel with low NOx emissions comprises a device for premixing air with the fuel to provide a lean fuel/air mixture; a nozzle having an internal bore through which the lean fuel/air mixture passes in a stream; and a flame stabilizer mounted in the stream of the lean fuel/air mixture. The flame stabilizer may be mounted in the internal bore, in which case, it is shaped and is spaced from the bore as just described. In a method of burning a lean fuel/air mixture, a lean fuel/air mixture is provided, and is directed in a stream; an annular eddy is created in the stream of the lean fuel/air mixture; and the lean fuel/air mixture is ignited at the eddy.
Evaluation of isotopic composition of fast reactor core in closed nuclear fuel cycle
NASA Astrophysics Data System (ADS)
Tikhomirov, Georgy; Ternovykh, Mikhail; Saldikov, Ivan; Fomichenko, Peter; Gerasimov, Alexander
2017-09-01
The strategy of the development of nuclear power in Russia provides for use of fast power reactors in closed nuclear fuel cycle. The PRORYV (i.e. «Breakthrough» in Russian) project is currently under development. Within the framework of this project, fast reactors BN-1200 and BREST-OD-300 should be built to, inter alia, demonstrate possibility of the closed nuclear fuel cycle technologies with plutonium as a main source of energy. Russia has a large inventory of plutonium which was accumulated in the result of reprocessing of spent fuel of thermal power reactors and conversion of nuclear weapons. This kind of plutonium will be used for development of initial fuel assemblies for fast reactors. The closed nuclear fuel cycle concept of the PRORYV assumes self-supplied mode of operation with fuel regeneration by neutron capture reaction in non-enriched uranium, which is used as a raw material. Operating modes of reactors and its characteristics should be chosen so as to provide the self-sufficient mode by using of fissile isotopes while refueling by depleted uranium and to support this state during the entire period of reactor operation. Thus, the actual issue is modeling fuel handling processes. To solve these problems, the code REPRORYV (Recycle for PRORYV) has been developed. It simulates nuclide streams in non-reactor stages of the closed fuel cycle. At the same time various verified codes can be used to evaluate in-core characteristics of a reactor. By using this approach various options for nuclide streams and assess the impact of different plutonium content in the fuel, fuel processing conditions, losses during fuel processing, as well as the impact of initial uncertainties on neutron-physical characteristics of reactor are considered in this study.
Fuel cell gas management system
DuBose, Ronald Arthur
2000-01-11
A fuel cell gas management system including a cathode humidification system for transferring latent and sensible heat from an exhaust stream to the cathode inlet stream of the fuel cell; an anode humidity retention system for maintaining the total enthalpy of the anode stream exiting the fuel cell equal to the total enthalpy of the anode inlet stream; and a cooling water management system having segregated deionized water and cooling water loops interconnected by means of a brazed plate heat exchanger.
Salvachua, Davinia; Mohagheghi, Ali; Smith, Holly; ...
2016-02-02
Co-production of chemicals from lignocellulosic biomass alongside fuels holds promise for improving the economic outlook of integrated biorefineries. In current biochemical conversion processes that use thermochemical pretreatment and enzymatic hydrolysis, fractionation of hemicellulose-derived and cellulose-derived sugar streams is possible using hydrothermal or dilute acid pretreatment (DAP), which then offers a route to parallel trains for fuel and chemical production from xylose- and glucose-enriched streams. Succinic acid (SA) is a co-product of particular interest in biorefineries because it could potentially displace petroleum-derived chemicals and polymer precursors for myriad applications. Furthermore, SA production from biomass-derived hydrolysates has not yet been fully exploredmore » or developed.« less
Thermal chemical recuperation method and system for use with gas turbine systems
Yang, W.C.; Newby, R.A.; Bannister, R.L.
1999-04-27
A system and method are disclosed for efficiently generating power using a gas turbine, a steam generating system and a reformer. The gas turbine receives a reformed fuel stream and an air stream and produces shaft power and exhaust. Some of the thermal energy from the turbine exhaust is received by the reformer. The turbine exhaust is then directed to the steam generator system that recovers thermal energy from it and also produces a steam flow from a water stream. The steam flow and a fuel stream are directed to the reformer that reforms the fuel stream and produces the reformed fuel stream used in the gas turbine. 2 figs.
Thermal chemical recuperation method and system for use with gas turbine systems
Yang, Wen-Ching; Newby, Richard A.; Bannister, Ronald L.
1999-01-01
A system and method for efficiently generating power using a gas turbine, a steam generating system (20, 22, 78) and a reformer. The gas turbine receives a reformed fuel stream (74) and an air stream and produces shaft power and exhaust. Some of the thermal energy from the turbine exhaust is received by the reformer (18). The turbine exhaust is then directed to the steam generator system that recovers thermal energy from it and also produces a steam flow from a water stream. The steam flow and a fuel stream are directed to the reformer that reforms the fuel stream and produces the reformed fuel stream used in the gas turbine.
Catalytic biomass pyrolysis process
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dayton, David C.; Gupta, Raghubir P.; Turk, Brian S.
Described herein are processes for converting a biomass starting material (such as lignocellulosic materials) into a low oxygen containing, stable liquid intermediate that can be refined to make liquid hydrocarbon fuels. More specifically, the process can be a catalytic biomass pyrolysis process wherein an oxygen removing catalyst is employed in the reactor while the biomass is subjected to pyrolysis conditions. The stream exiting the pyrolysis reactor comprises bio-oil having a low oxygen content, and such stream may be subjected to further steps, such as separation and/or condensation to isolate the bio-oil.
Undercover isotopes: tracking the fate of nitrogen in streams
Rhonda Mazza; Sherri Johnson
2009-01-01
Excess nitrogen stemming from human activities is a common water pollutant. Fertilizer runoff, sewage, and fossil fuel emission all contain nitrogen that often ends in streams, rivers, and ultimately the ocean. Research has found that more nitrogen enters a river system than can be accounted for at its mouth, indicating that instream processing is occurring. A team of...
PLUTONIUM FUEL RODS FOR PREPARATION OF TRANSPLUTONIC ELEMENTS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bailey, W.J.
1962-02-01
Production by coextrusion of metallurgically bonded, Alclad, Al-7.35 wt% Pu alloy fuel rods with integral ends is discussed. The rods had a diameter of 0.94 in., length of, 60 in., and a nominal cladding thickness of 0.070 in. The Pu concentration was maintained at 83.3 g/rod. The coextrusion billets can be assembled with fuel cores in the as-cast condition. The casting hot-tops can be returned to the process stream. The process is useful for preparing transplutonic elements and production of high-exposure Pu. (J.R.D.)
Survey on aging on electrodes and electrocatalysts in phosphoric acid fuel cells
NASA Technical Reports Server (NTRS)
Stonehart, P.; Hochmuth, J.
1981-01-01
The processes which contribute to the decay in performance of electrodes used in phosphoric acid fuel cell systems are discussed. Loss of catalytic surface area, corrosion of the carbon support, electrode structure degradation, electrolyte degradation, and impurities in the reactant streams are identified as the major areas for concern.
Method of controlling injection of oxygen into hydrogen-rich fuel cell feed stream
Meltser, Mark Alexander; Gutowski, Stanley; Weisbrod, Kirk
2001-01-01
A method of operating a H.sub.2 --O.sub.2 fuel cell fueled by hydrogen-rich fuel stream containing CO. The CO content is reduced to acceptable levels by injecting oxygen into the fuel gas stream. The amount of oxygen injected is controlled in relation to the CO content of the fuel gas, by a control strategy that involves (a) determining the CO content of the fuel stream at a first injection rate, (b) increasing the O.sub.2 injection rate, (c) determining the CO content of the stream at the higher injection rate, (d) further increasing the O.sub.2 injection rate if the second measured CO content is lower than the first measured CO content or reducing the O.sub.2 injection rate if the second measured CO content is greater than the first measured CO content, and (e) repeating steps a-d as needed to optimize CO consumption and minimize H.sub.2 consumption.
Aerobic mineralization of MTBE and tert-butyl alcohol by stream-bed sediment microorganisms
Bradley, P.M.; Landmeyer, J.E.; Chapelle, F.H.
1999-01-01
Microorganisms indigenous to the stream-bed sediments at two gasoline- contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.Microorganisms indigenous to the stream-bed sediments at two gasoline-contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.
Task 3.9 -- Catalytic tar cracking. Semi-annual report, January 1--June 30, 1995
DOE Office of Scientific and Technical Information (OSTI.GOV)
Young, B.C.; Timpe, R.C.
1995-12-31
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 bymore » these catalysts to produce a desired liquid and/or gas stream. Results to date are presented in the cited papers.« less
Sun, Min; Song, Wei; Zhai, Lin-Feng; Cui, Yu-Zhi
2013-12-15
The chelated-iron process is among the most promising techniques for the hydrogen sulfide (H2S) removal due to its double advantage of waste minimization and resource recovery. However, this technology has encountered the problem of chelate degradation which made it difficult to ensure reliable and economical operation. This work aims to develop a novel fuel-cell-assisted chelated-iron process which employs an air-cathode fuel cell for the catalyst regeneration. By using such a process, sulfur and electricity were effectively recovered from H2S and the problem of chelate degradation was well controlled. Experiment on a synthetic sulfide solution showed the fuel-cell-assisted chelated-iron process could maintain high sulfur recovery efficiencies generally above 90.0%. The EDTA was preferable to NTA as the chelating agent for electricity generation, given the Coulombic efficiencies (CEs) of 17.8 ± 0.5% to 75.1 ± 0.5% for the EDTA-chelated process versus 9.6 ± 0.8% to 51.1 ± 2.7% for the NTA-chelated process in the pH range of 4.0-10.0. The Fe (III)/S(2-) ratio exhibited notable influence on the electricity generation, with the CEs improved by more than 25% as the Fe (III)/S(2-) molar ratio increased from 2.5:1 to 3.5:1. Application of this novel process in treating a H2S-containing biogas stream achieved 99% of H2S removal efficiency, 78% of sulfur recovery efficiency, and 78.6% of energy recovery efficiency, suggesting the fuel-cell-assisted chelated-iron process was effective to remove the H2S from gas streams with favorable sulfur and energy recovery efficiencies. Copyright © 2013 Elsevier B.V. All rights reserved.
1992-06-01
streams (Oxitron system). The system combines the features of activated sludge and fixed-film biological processes (see Appendix F, Biotechnologies...contaminated aqueous streams. The system combines the features of activated sludge and fixed-film biological processes (see Appendix F, Biotechnologies in... marine oil spills have been estimated to average $6.50/gal of spilled oil (Bartha and Atlas, 1977). This translates to roughly $2000 per metric ton
Critical flow rate of anode fuel exhaust in a PEM fuel cell system
NASA Astrophysics Data System (ADS)
Zhu, Wenhua H.; Payne, Robert U.; Tatarchuk, Bruce J.
A manual purge line was added into the exterior fuel exhaust stream of a Ballard PEM stack in a Nexa™ power module. With the addition of manual exhaust purge, high levels of inert gases were intentionally added to the anode feed without changing normal operational procedures. A new method of determining the critical minimum flow rate in the anode exhaust stream was given by an anode mass balance. This type of operation makes dual use of membranes in the MEAs as both gas purifiers and as solid electrolytes. The PEM stack was successfully operated with up to ca. 7% nitrogen or carbon dioxide in the absence of a palladium-based hydrogen separator at ca. 200 W power level. Nitrogen in the anode stream was concentrated from 7.5% to 91.6%. The system maintained a fuel efficiency of 99% at a manual purge rate of 2.22 ml s -1 and no auto purge. The fuel cell stack efficiency was 64% and the stack output efficiency was 75%. The overall system efficiency was 39%. After troublesome CO and H 2S poisons were removed, a hydrocarbon reformate containing high levels of CO 2 and H 2O was further used in the Nexa™ stack. The size and complexity of the fuel processing system may be reduced at a specified power level by using this operational method.
Aerospace Fuels From Nonpetroleum Raw Materials
NASA Technical Reports Server (NTRS)
Palaszewski, Bryan A.; Hepp, Aloysius F.; Kulis, Michael J.; Jaworske, Donald A.
2013-01-01
Recycling human metabolic and plastic wastes minimizes cost and increases efficiency by reducing the need to transport consumables and return trash, respectively, from orbit to support a space station crew. If the much larger costs of transporting consumables to the Moon and beyond are taken into account, developing waste recycling technologies becomes imperative and possibly mission enabling. Reduction of terrestrial waste streams while producing energy and/or valuable raw materials is an opportunity being realized by a new generation of visionary entrepreneurs; several relevant technologies are briefly compared, contrasted and assessed for space applications. A two-step approach to nonpetroleum raw materials utilization is presented; the first step involves production of supply or producer gas. This is akin to synthesis gas containing carbon oxides, hydrogen, and simple hydrocarbons. The second step involves production of fuel via the Sabatier process, a methanation reaction, or another gas-to-liquid technology, typically Fischer-Tropsch processing. Optimization to enhance the fraction of product stream relevant to transportation fuels via catalytic (process) development at NASA Glenn Research Center is described. Energy utilization is a concern for production of fuels whether for operation on the lunar or Martian surface, or beyond. The term green relates to not only mitigating excess carbon release but also to the efficiency of energy usage. For space, energy usage can be an essential concern. Another issue of great concern is minimizing impurities in the product stream(s), especially those that are potential health risks and/or could degrade operations through catalyst poisoning or equipment damage; technologies being developed to remove heteroatom impurities are discussed. Alternative technologies to utilize waste fluids, such as a propulsion option called the resistojet, are discussed. The resistojet is an electric propulsion technology with a powered thruster to vaporize and heat a propellant to high temperature, hot gases are subsequently passed through a converging-diverging nozzle expanding gases to supersonic velocities. A resistojet can accommodate many different fluids, including various reaction chamber (by-)products.
Aerospace Fuels from Nonpetroleum Raw Materials
NASA Technical Reports Server (NTRS)
Palaszewski, B. A.; Hepp, A. F.; Kulis, M. J.; Jaworske, D. A.
2013-01-01
Recycling human metabolic and plastic wastes minimizes cost and increases efficiency by reducing the need to transport consumables and return trash, respectively, from orbit to support a space station crew. If the much larger costs of transporting consumables to the Moon and beyond are taken into account, developing waste recycling technologies becomes imperative and possibly mission enabling. Reduction of terrestrial waste streams while producing energy and/or valuable raw materials is an opportunity being realized by a new generation of visionary entrepreneurs; several relevant technologies are briefly compared, contrasted and assessed for space applications. A two-step approach to nonpetroleum raw materials utilization is presented; the first step involves production of supply or producer gas. This is akin to synthesis gas containing carbon oxides, hydrogen, and simple hydrocarbons. The second step involves production of fuel via the Sabatier process, a methanation reaction, or another gas-to-liquid technology, typically Fischer- Tropsch processing. Optimization to enhance the fraction of product stream relevant to transportation fuels via catalytic (process) development at NASA GRC is described. Energy utilization is a concern for production of fuels whether for operation on the lunar or Martian surface, or beyond. The term "green" relates to not only mitigating excess carbon release but also to the efficiency of energy usage. For space, energy usage can be an essential concern. Other issues of great concern include minimizing impurities in the product stream(s), especially those that are potential health risks and/or could de-grade operations through catalyst poisoning or equipment damage; technologies being developed to remove heteroatom impurities are discussed. Alternative technologies to utilize waste fluids, such as a propulsion option called the resistojet, are discussed. The resistojet is an electric propulsion technology with a powered thruster to vaporize and heat a propellant to high temperature, hot gases are subsequently passed through a converging-diverging nozzle expanding gases to supersonic velocities. A resistojet can accommodate many different fluids, including various reaction chamber (by-)products.
Direct production of fractionated and upgraded hydrocarbon fuels from biomass
Felix, Larry G.; Linck, Martin B.; Marker, Terry L.; Roberts, Michael J.
2014-08-26
Multistage processing of biomass to produce at least two separate fungible fuel streams, one dominated by gasoline boiling-point range liquids and the other by diesel boiling-point range liquids. The processing involves hydrotreating the biomass to produce a hydrotreatment product including a deoxygenated hydrocarbon product of gasoline and diesel boiling materials, followed by separating each of the gasoline and diesel boiling materials from the hydrotreatment product and each other.
Green Aerospace Fuels from Nonpetroleum Sources
NASA Technical Reports Server (NTRS)
Hepp, Aloysius F.; Kulis, Michael J.; DeLaRee, Ana B.; Zubrin, Robert; Berggren, Mark; Hensel, Joseph D.; Kimble, Michael C.
2011-01-01
Efforts to produce green aerospace propellants from nonpetroleum sources are outlined. The paper begins with an overview of feedstock processing and relevant small molecule or C1 chemistry. Gas-to-liquid technologies, notably Fischer-Tropsch (FT) processing of synthesis gas (CO and H2), are being optimized to enhance the fraction of product stream relevant to aviation (and other transportation) fuels at the NASA Glenn Research Center (GRC). Efforts to produce optimized catalysts are described. Given the high cost of space launch, the recycling of human metabolic and plastic wastes to reduce the need to transport consumables to orbit to support the crew of a space station has long been recognized as a high priority. If the much larger costs of transporting consumables to the Moon or beyond are taken into account, the importance of developing waste recycling systems becomes still more imperative. One promising way to transform organic waste products into useful gases is steam reformation; this well-known technology is currently being optimized by a Colorado company for exploration and planetary surface operations. Reduction of terrestrial waste streams while producing energy and/or valuable raw materials is an opportunity being realized by a new generation of visionary entrepreneurs. A technology that has successfully demonstrated production of fuels and related chemicals from waste plastics developed in Northeast Ohio is described. Technologies being developed by a Massachusetts company to remove sulfur impurities are highlighted. Common issues and concerns for nonpetroleum fuel production are emphasized. Energy utilization is a concern for production of fuels whether a terrestrial operation or on the lunar (or Martian) surface; the term green relates to not only mitigating excess carbon release but also to the efficiency of grid-energy usage. For space exploration, energy efficiency can be an essential concern. Other issues of great concern include minimizing impurities in the product stream(s), especially those that potential health risks and/or could degrade operations through catalyst poisoning or equipment damage. The potential impacts on future missions by such concerns are addressed in closing.
Separation of uranium from technetium in recovery of spent nuclear fuel
NASA Astrophysics Data System (ADS)
Friedman, H. A.
1984-06-01
A method for decontaminating uranium product from the Purex 5 process is described. Hydrazine is added to the product uranyl nitrate stream from the Purex process, which contains hexavalent (UO2(2+)) uranium and heptavalent technetius (TcO4-). Technetium in the product stream is reduced and then complexed by the addition of oxalic acid (H2O2O4), and the Tc-oxalate complex is readily separated from the 10 uranium by solvent extraction with 30 vol % tributyl phosphate in n-dodecane.
Oxy-fuel combustion with integrated pollution control
Patrick, Brian R [Chicago, IL; Ochs, Thomas Lilburn [Albany, OR; Summers, Cathy Ann [Albany, OR; Oryshchyn, Danylo B [Philomath, OR; Turner, Paul Chandler [Independence, OR
2012-01-03
An oxygen fueled integrated pollutant removal and combustion system includes a combustion system and an integrated pollutant removal system. The combustion system includes a furnace having at least one burner that is configured to substantially prevent the introduction of air. An oxygen supply supplies oxygen at a predetermine purity greater than 21 percent and a carbon based fuel supply supplies a carbon based fuel. Oxygen and fuel are fed into the furnace in controlled proportion to each other and combustion is controlled to produce a flame temperature in excess of 3000 degrees F. and a flue gas stream containing CO2 and other gases. The flue gas stream is substantially void of non-fuel borne nitrogen containing combustion produced gaseous compounds. The integrated pollutant removal system includes at least one direct contact heat exchanger for bringing the flue gas into intimated contact with a cooling liquid to produce a pollutant-laden liquid stream and a stripped flue gas stream and at least one compressor for receiving and compressing the stripped flue gas stream.
Experimental investigation of burning rates of pure ethanol and ethanol blended fuels
DOE Office of Scientific and Technical Information (OSTI.GOV)
Parag, Shintre; Raghavan, Vasudevan
2009-05-15
A fundamental experimental study to determine the burning rates of ethanol and ethanol-blended fossil fuels is presented. Pure liquid ethanol or its blends with liquid fossil fuels such as gasoline or diesel, has been transpired to the surface a porous sphere using an infusion pump. Burning of the fuel takes place on the surface of the porous sphere, which is placed in an air stream blowing upwards with a uniform velocity at atmospheric pressure and temperature under normal gravity conditions. At low air velocities, when ignited, a flame envelopes the sphere. For each sphere size, air stream velocity and fuelmore » type, the fuel feed rate will vary and the same is recorded as the burning rate for that configuration. The flame stand-off distances from the sphere surface are measured by post-processing the digital image of the flame photograph using suitable imaging software. The transition velocity at which the flame moves and establishes itself at the wake region of the sphere has been determined for different diameters and fuel types. Correlations of these parameters are also presented. (author)« less
Fuel cell system logic for differentiating between rapid and normal shutdown commands
Keskula, Donald H.; Doan, Tien M.; Clingerman, Bruce J.
2000-01-01
A method of controlling the operation of a fuel cell system wherein each shutdown command for the system is subjected to decision logic which determines whether the command should be a normal shutdown command or rapid shutdown command. If the logic determines that the shutdown command should be a normal shutdown command, then the system is shutdown in a normal step-by-step process in which the hydrogen stream is consumed within the system. If the logic determines that the shutdown command should be a rapid shutdown command, the hydrogen stream is removed from the system either by dumping to atmosphere or routing to storage.
Chemical Technology Division annual technical report, 1992
DOE Office of Scientific and Technical Information (OSTI.GOV)
Battles, J.E.; Myles, K.M.; Laidler, J.J.
1993-06-01
In this period, CMT conducted research and development in the following areas: (1) electrochemical technology, including advanced batteries and fuel cells; (2) technology for fluidized-bed combustion and coal-fired magnetohydrodynamics; (3) methods for treatment of hazardous waste, mixed hazardous/radioactive waste, and municipal solid waste; (4) the reaction of nuclear waste glass and spent fuel under conditions expected for an unsaturated repository; (5) processes for separating and recovering transuranic elements from nuclear waste streams, treating water contaminated with volatile organics, and concentrating radioactive waste streams; (6) recovery processes for discharged fuel and the uranium blanket in the Integral Fast Reactor (EFR); (7)more » processes for removal of actinides in spent fuel from commercial water-cooled nuclear reactors and burnup in IFRs; and (8) physical chemistry of selected materials (corium; Fe-U-Zr, tritium in LiAlO{sub 2} in environments simulating those of fission and fusion energy systems. The Division also conducts basic research in catalytic chemistry associated with molecular energy resources and novel` ceramic precursors; materials chemistry of superconducting oxides, electrified metal/solution interfaces, and molecular sieve structures; and the geochemical processes involved in water-rock interactions occurring in active hydrothermal systems. In addition, the Analytical Chemistry Laboratory in CMT provides a broad range of analytical chemistry support services to the technical programs at Argonne National Laboratory (ANL).« less
The study of integrated coal-gasifier molten carbonate fuel cell systems
NASA Technical Reports Server (NTRS)
1983-01-01
A novel integration concept for a coal-fueled coal gasifier-molten carbonate fuel cell power plant was studied. Effort focused on determining the efficiency potential of the concept, design, and development requirements of the processes in order to achieve the efficiency. The concept incorporates a methane producing catalytic gasifier of the type previously under development by Exxon Research and Development Corp., a reforming molten carbonate fuel cell power section of the type currently under development by United Technologies Corp., and a gasifier-fuel cell recycle loop. The concept utilizes the fuel cell waste heat, in the form of hydrogen and carbon monoxide, to generate additional fuel in the coal gasifier, thereby eliminating the use of both an O2 plant and a stream bottoming cycle from the power plant. The concept has the potential for achieving coal-pile-to-busbar efficiencies of 50-59%, depending on the process configuration and degree of process configuration and degree of process development requirements. This is significantly higher than any previously reported gasifier-molten carbonate fuel cell system.
26 CFR 48.4081-1 - Taxable fuel; definitions.
Code of Federal Regulations, 2011 CFR
2011-04-01
... xylene); (L) Natural gasoline; (M) Pentane; (N) Pentane mixture; (O) Polymer gasoline; (P) Raffinate; (Q... hydrocarbon stream that is produced in a natural gas processing plant is not a gasoline blendstock if the...
Local impact of humidification on degradation in polymer electrolyte fuel cells
NASA Astrophysics Data System (ADS)
Sanchez, Daniel G.; Ruiu, Tiziana; Biswas, Indro; Schulze, Mathias; Helmly, Stefan; Friedrich, K. Andreas
2017-06-01
The water level in a polymer electrolyte membrane fuel cell (PEMFC) affects the durability as is seen from the degradation processes during operation a PEMFC with fully- and nonhumidified gas streams as analyzed using an in-situ segmented cell for local current density measurements during a 300 h test operating under constant conditions and using ex situ SEM/EDX and XPS post-test analysis of specific regions. The impact of the RH on spatial distribution of the degradation process results from different water distribution giving different chemical environments. Under nonhumidified gas streams, the cathode inlet region exhibits increased degradation, whereas with fully humidified gases the bottom of the cell had the higher performance losses. The degradation and the degree of reversibility produced by Pt dissolution, PTFE defluorination, and contaminants such as silicon (Si) and nickel (Ni) were locally evaluated.
INTEGRATED POWER GENERATION SYSTEMS FOR COAL MINE WASTE METHANE UTILIZATION
DOE Office of Scientific and Technical Information (OSTI.GOV)
Peet M. Soot; Dale R. Jesse; Michael E. Smith
2005-08-01
An integrated system to utilize the waste coal mine methane (CMM) at the Federal No. 2 Coal Mine in West Virginia was designed and built. The system includes power generation, using internal combustion engines, along with gas processing equipment to upgrade sub-quality waste methane to pipeline quality standards. The power generation has a nominal capacity of 1,200 kw and the gas processing system can treat about 1 million cubic feet per day (1 MMCFD) of gas. The gas processing is based on the Northwest Fuel Development, Inc. (NW Fuel) proprietary continuous pressure swing adsorption (CPSA) process that can remove nitrogenmore » from CMM streams. The two major components of the integrated system are synergistic. The byproduct gas stream from the gas processing equipment can be used as fuel for the power generating equipment. In return, the power generating equipment provides the nominal power requirements of the gas processing equipment. This Phase III effort followed Phase I, which was comprised of a feasibility study for the project, and Phase II, where the final design for the commercial-scale demonstration was completed. The fact that NW Fuel is desirous of continuing to operate the equipment on a commercial basis provides the validation for having advanced the project through all of these phases. The limitation experienced by the project during Phase III was that the CMM available to operate the CPSA system on a commercial basis was not of sufficiently high quality. NW Fuel's CPSA process is limited in its applicability, requiring a relatively high quality of gas as the feed to the process. The CPSA process was demonstrated during Phase III for a limited time, during which the processing capabilities met the expected results, but the process was never capable of providing pipeline quality gas from the available low quality CMM. The NW Fuel CPSA process is a low-cost ''polishing unit'' capable of removing a few percent nitrogen. It was never intended to process CMM streams containing high levels of nitrogen, as is now the case at the Federal No.2 Mine. Even lacking the CPSA pipeline delivery demonstration, the project was successful in laying the groundwork for future commercial applications of the integrated system. This operation can still provide a guide for other coal mines which need options for utilization of their methane resources. The designed system can be used as a complete template, or individual components of the system can be segregated and utilized separately at other mines. The use of the CMM not only provides an energy fuel from an otherwise wasted resource, but it also yields an environmental benefit by reducing greenhouse gas emissions. The methane has twenty times the greenhouse effect as compared to carbon dioxide, which the combustion of the methane generates. The net greenhouse gas emission mitigation is substantial.« less
Code of Federal Regulations, 2014 CFR
2014-07-01
... Production § 63.1426 Process vent requirements for determining organic HAP concentration, control efficiency..., total organic HAP, or as TOC minus methane and ethane according to the procedures specified. When... methane and ethane) concentrations in all process vent streams and primary and secondary fuels introduced...
40 CFR 63.491 - Batch front-end process vents-recordkeeping requirements.
Code of Federal Regulations, 2010 CFR
2010-07-01
... (b)(2): (i) For an incinerator or non-combustion control device, the percent reduction of organic HAP... the process vent stream is introduced with combustion air or is used as a secondary fuel and is not... combustion device to control halogenated batch front-end process vents or halogenated aggregate batch vent...
40 CFR 63.1413 - Compliance demonstration procedures.
Code of Federal Regulations, 2010 CFR
2010-07-01
... liquids, other than fuels, received by the control device. (i) For a scrubber, the design evaluation shall... scrubbing liquid. The design evaluation shall establish the design exhaust vent stream organic compound... process vent and the overall percent reduction for the collection of non-reactor batch process vents...
Separation of uranium from technetium in recovery of spent nuclear fuel
Friedman, H.A.
1984-06-13
A method for decontaminating uranium product from the Purex 5 process comprises addition of hydrazine to the product uranyl nitrate stream from the Purex process, which contains hexavalent (UO/sub 2//sup 2 +/) uranium and heptavalent technetium (TcO/sub 4/-). Technetium in the product stream is reduced and then complexed by the addition of oxalic acid (H/sub 2/C/sub 2/O/sub 4/), and the Tc-oxalate complex is readily separated from the 10 uranium by solvent extraction with 30 vol % tributyl phosphate in n-dodecane.
Separation of uranium from technetium in recovery of spent nuclear fuel
Friedman, Horace A.
1985-01-01
A method for decontaminating uranium product from the Purex process comprises addition of hydrazine to the product uranyl nitrate stream from the Purex process, which contains hexavalent (UO.sub.2.sup.2+) uranium and heptavalent technetium (TcO.sub.4 -). Technetium in the product stream is reduced and then complexed by the addition of oxalic acid (H.sub.2 C.sub.2 O.sub.4), and the Tc-oxalate complex is readily separated from the uranium by solvent extraction with 30 vol. % tributyl phosphate in n-dodecane.
Fuel and oxygen addition for metal smelting or refining process
Schlichting, Mark R.
1994-01-01
A furnace 10 for smelting iron ore and/or refining molten iron 20 is equipped with an overhead pneumatic lance 40, through which a center stream of particulate coal 53 is ejected at high velocity into a slag layer 30. An annular stream of nitrogen or argon 51 enshrouds the coal stream. Oxygen 52 is simultaneously ejected in an annular stream encircling the inert gas stream 51. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus 84 to react with carbon monoxide gas rising from slag layer 30, thereby adding still more heat to the furnace.
Fuel and oxygen addition for metal smelting or refining process
Schlichting, M.R.
1994-11-22
A furnace for smelting iron ore and/or refining molten iron is equipped with an overhead pneumatic lance, through which a center stream of particulate coal is ejected at high velocity into a slag layer. An annular stream of nitrogen or argon enshrouds the coal stream. Oxygen is simultaneously ejected in an annular stream encircling the inert gas stream. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus to react with carbon monoxide gas rising from slag layer, thereby adding still more heat to the furnace. 7 figs.
NASA Astrophysics Data System (ADS)
Varady, M. J.; McLeod, L.; Meacham, J. M.; Degertekin, F. L.; Fedorov, A. G.
2007-09-01
Portable fuel cells are an enabling technology for high efficiency and ultra-high density distributed power generation, which is essential for many terrestrial and aerospace applications. A key element of fuel cell power sources is the fuel processor, which should have the capability to efficiently reform liquid fuels and produce high purity hydrogen that is consumed by the fuel cells. To this end, we are reporting on the development of two novel MEMS hydrogen generators with improved functionality achieved through an innovative process organization and system integration approach that exploits the advantages of transport and catalysis on the micro/nano scale. One fuel processor design utilizes transient, reverse-flow operation of an autothermal MEMS microreactor with an intimately integrated, micromachined ultrasonic fuel atomizer and a Pd/Ag membrane for in situ hydrogen separation from the product stream. The other design features a simpler, more compact planar structure with the atomized fuel ejected directly onto the catalyst layer, which is coupled to an integrated hydrogen selective membrane.
Closed Fuel Cycle Waste Treatment Strategy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vienna, J. D.; Collins, E. D.; Crum, J. V.
This study is aimed at evaluating the existing waste management approaches for nuclear fuel cycle facilities in comparison to the objectives of implementing an advanced fuel cycle in the U.S. under current legal, regulatory, and logistical constructs. The study begins with the Global Nuclear Energy Partnership (GNEP) Integrated Waste Management Strategy (IWMS) (Gombert et al. 2008) as a general strategy and associated Waste Treatment Baseline Study (WTBS) (Gombert et al. 2007). The tenets of the IWMS are equally valid to the current waste management study. However, the flowsheet details have changed significantly from those considered under GNEP. In addition, significantmore » additional waste management technology development has occurred since the GNEP waste management studies were performed. This study updates the information found in the WTBS, summarizes the results of more recent technology development efforts, and describes waste management approaches as they apply to a representative full recycle reprocessing flowsheet. Many of the waste management technologies discussed also apply to other potential flowsheets that involve reprocessing. These applications are occasionally discussed where the data are more readily available. The report summarizes the waste arising from aqueous reprocessing of a typical light-water reactor (LWR) fuel to separate actinides for use in fabricating metal sodium fast reactor (SFR) fuel and from electrochemical reprocessing of the metal SFR fuel to separate actinides for recycle back into the SFR in the form of metal fuel. The primary streams considered and the recommended waste forms include; Tritium in low-water cement in high integrity containers (HICs); Iodine-129: As a reference case, a glass composite material (GCM) formed by the encapsulation of the silver Mordenite (AgZ) getter material in a low-temperature glass is assumed. A number of alternatives with distinct advantages are also considered including a fused silica waste form with encapsulated nano-sized AgI crystals; Carbon-14 immobilized as a CaCO3 in a cement waste form; Krypton-85 stored as a compressed gas; An aqueous reprocessing high-level waste (HLW) raffinate waste immobilized by the vitrification process; An undissolved solids (UDS) fraction from aqueous reprocessing of LWR fuel either included in the borosilicate HLW glass or immobilized in the form of a metal alloy or titanate ceramics; Zirconium-based LWR fuel cladding hulls and stainless steel (SS) fuel assembly hardware super-compacted for disposal or purified for reuse (or disposal as low-level waste, LLW) of Zr by reactive gas separations; Electrochemical process salt HLW incorporated into a glass bonded Sodalite waste form; and Electrochemical process UDS and SS cladding hulls melted into an iron based alloy waste form. Mass and volume estimates for each of the recommended waste forms based on the source terms from a representative flowsheet are reported. In addition to the above listed primary waste streams, a range of secondary process wastes are generated by aqueous reprocessing of LWR fuel, metal SFR fuel fabrication, and electrochemical reprocessing of SFR fuel. These secondary wastes have been summarized and volumes estimated by type and classification. The important waste management data gaps and research needs have been summarized for each primary waste stream and selected waste process.« less
Recuperated atmospheric SOFC/gas turbine hybrid cycle
Lundberg, Wayne
2010-05-04
A method of operating an atmospheric-pressure solid oxide fuel cell generator (6) in combination with a gas turbine comprising a compressor (1) and expander (2) where an inlet oxidant (20) is passed through the compressor (1) and exits as a first stream (60) and a second stream (62) the first stream passing through a flow control valve (56) to control flow and then through a heat exchanger (54) followed by mixing with the second stream (62) where the mixed streams are passed through a combustor (8) and expander (2) and the first heat exchanger for temperature control before entry into the solid oxide fuel cell generator (6), which generator (6) is also supplied with fuel (40).
Recuperated atmosphere SOFC/gas turbine hybrid cycle
Lundberg, Wayne
2010-08-24
A method of operating an atmospheric-pressure solid oxide fuel cell generator (6) in combination with a gas turbine comprising a compressor (1) and expander (2) where an inlet oxidant (20) is passed through the compressor (1) and exits as a first stream (60) and a second stream (62) the first stream passing through a flow control valve (56) to control flow and then through a heat exchanger (54) followed by mixing with the second stream (62) where the mixed streams are passed through a combustor (8) and expander (2) and the first heat exchanger for temperature control before entry into the solid oxide fuel cell generator (6), which generator (6) is also supplied with fuel (40).
Energy Supply- Production of Fuel from Agricultural and Animal Waste
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gabriel Miller
2009-03-25
The Society for Energy and Environmental Research (SEER) was funded in March 2004 by the Department of Energy, under grant DE-FG-36-04GO14268, to produce a study, and oversee construction and implementation, for the thermo-chemical production of fuel from agricultural and animal waste. The grant focuses on the Changing World Technologies (CWT) of West Hempstead, NY, thermal conversion process (TCP), which converts animal residues and industrial food processing biproducts into fuels, and as an additional product, fertilizers. A commercial plant was designed and built by CWT, partially using grant funds, in Carthage, Missouri, to process animal residues from a nearby turkey processingmore » plant. The DOE sponsored program consisted of four tasks. These were: Task 1 Optimization of the CWT Plant in Carthage - This task focused on advancing and optimizing the process plant operated by CWT that converts organic waste to fuel and energy. Task 2 Characterize and Validate Fuels Produced by CWT - This task focused on testing of bio-derived hydrocarbon fuels from the Carthage plant in power generating equipment to determine the regulatory compliance of emissions and overall performance of the fuel. Task 3 Characterize Mixed Waste Streams - This task focused on studies performed at Princeton University to better characterize mixed waste incoming streams from animal and vegetable residues. Task 4 Fundamental Research in Waste Processing Technologies - This task focused on studies performed at the Massachusetts Institute of Technology (MIT) on the chemical reformation reaction of agricultural biomass compounds in a hydrothermal medium. Many of the challenges to optimize, improve and perfect the technology, equipment and processes in order to provide an economically viable means of creating sustainable energy were identified in the DOE Stage Gate Review, whose summary report was issued on July 30, 2004. This summary report appears herein as Appendix 1, and the findings of the report formed the basis for much of the subsequent work under the grant. An explanation of the process is presented as well as the completed work on the four tasks.« less
Refining and blending of aviation turbine fuels.
White, R D
1999-02-01
Aviation turbine fuels (jet fuels) are similar to other petroleum products that have a boiling range of approximately 300F to 550F. Kerosene and No.1 grades of fuel oil, diesel fuel, and gas turbine oil share many similar physical and chemical properties with jet fuel. The similarity among these products should allow toxicology data on one material to be extrapolated to the others. Refineries in the USA manufacture jet fuel to meet industry standard specifications. Civilian aircraft primarily use Jet A or Jet A-1 fuel as defined by ASTM D 1655. Military aircraft use JP-5 or JP-8 fuel as defined by MIL-T-5624R or MIL-T-83133D respectively. The freezing point and flash point are the principle differences between the finished fuels. Common refinery processes that produce jet fuel include distillation, caustic treatment, hydrotreating, and hydrocracking. Each of these refining processes may be the final step to produce jet fuel. Sometimes blending of two or more of these refinery process streams are needed to produce jet fuel that meets the desired specifications. Chemical additives allowed for use in jet fuel are also defined in the product specifications. In many cases, the customer rather than the refinery will put additives into the fuel to meet their specific storage or flight condition requirements.
Atomization and vaporization characteristics of airblast fuel injection inside a venturi tube
NASA Technical Reports Server (NTRS)
Sun, H.; Chue, T.-H.; Lai, M.-C.; Tacina, R. R.
1993-01-01
This paper describes the experimental and numerical characterization of the capillary fuel injection, atomization, dispersion, and vaporization of liquid fuel in a coflowing air stream inside a single venturi tube. The experimental techniques used are all laser-based. Phase Doppler analyzer was used to characterize the atomization and vaporization process. Planar laser-induced fluorescence visualizations give good qualitative picture of the fuel droplet and vapor distribution. Limited quantitative capabilities of the technique are also demonstrated. A modified version of the KIVA-II was used to simulate the entire spray process, including breakup and vaporization. The advantage of venturi nozzle is demonstrated in terms of better atomization, more uniform F/A distribution, and less pressure drop. Multidimensional spray calculations can be used as a design tool only if care is taken for the proper breakup model, and wall impingement process.
A U-bearing composite waste form for electrochemical processing wastes
NASA Astrophysics Data System (ADS)
Chen, X.; Ebert, W. L.; Indacochea, J. E.
2018-04-01
Metallic/ceramic composite waste forms are being developed to immobilize combined metallic and oxide waste streams generated during electrochemical recycling of used nuclear fuel. Composites were made for corrosion testing by reacting HT9 steel to represent fuel cladding, Zr and Mo to simulate metallic fuel waste, and a mixture of ZrO2, Nd2O3, and UO2 to represent oxide wastes. More than half of the added UO2 was reduced to metal and formed Fe-Zr-U intermetallics and most of the remaining UO2 and all of the Nd2O3 reacted to form zirconates. Fe-Cr-Mo intermetallics were also formed. Microstructure characterization of the intermetallic and ceramic phases that were generated and tests conducted to evaluate their corrosion behaviors indicate composite waste forms can accommodate both metallic and oxidized waste streams in durable host phases.
A U-bearing composite waste form for electrochemical processing wastes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chen, X.; Ebert, W. L.; Indacochea, J. E.
Metallic/ceramic composite waste forms are being developed to immobilize combined metallic and oxide waste streams generated during electrochemical recycling of used nuclear fuel. Composites were made for corrosion testing by reacting HT9 steel to represent fuel cladding, Zr and Mo to simulate metallic fuel waste, and a mixture of ZrO2, Nd2O3, and UO2 to represent oxide wastes. More than half of the added UO2 was reduced to metal and formed Fe-Zr-U intermetallics and most of the remaining UO2 and all of the Nd2O3 reacted to form zirconates. Fe-Cr-Mo intermetallics were also formed. Microstructure characterization of the intermetallic and ceramic phasesmore » that were generated and tests conducted to evaluate their corrosion behaviors indicate composite waste forms can accommodate both metallic and oxidized waste streams in durable host phases. (c) 2018 Elsevier B.V. All rights reserved.« less
Potential synergy: the thorium fuel cycle and rare earths processing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ault, T.; Wymer, R.; Croff, A.
2013-07-01
The use of thorium in nuclear power programs has been evaluated on a recurring basis. A concern often raised is the lack of 'thorium infrastructure'; however, for at least a part of a potential thorium fuel cycle, this may less of a problem than previously thought. Thorium is frequently encountered in association with rare earth elements and, since the U.S. last systematically evaluated the large-scale use of thorium (the 1970's,) the use of rare earth elements has increased ten-fold to approximately 200,000 metric tons per year. Integration of thorium extraction with rare earth processing has been previously described and top-levelmore » estimates have been done on thorium resource availability; however, since ores and mining operations differ markedly, what is needed is process flowsheet analysis to determine whether a specific mining operation can feasibly produce thorium as a by-product. Also, the collocation of thorium with rare earths means that, even if a thorium product stream is not developed, its presence in mining waste streams needs to be addressed and there are previous instances where this has caused issues. This study analyzes several operational mines, estimates the mines' ability to produce a thorium by-product stream, and discusses some waste management implications of recovering thorium. (authors)« less
Reforming Biomass Derived Pyrolysis Bio-oil Aqueous Phase to Fuels
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mukarakate, Calvin; Evans, Robert J.; Deutch, Steve
Fast pyrolysis and catalytic fast pyrolysis (CFP) of biomass produce a liquid product stream comprised of various classes of organic compounds having different molecule size and polarity. This liquid, either spontaneously in the case of catalytic fast pyrolysis or by water addition for the non-catalytic process separates into a non-polar organic-rich fraction and a highly polar water-rich fraction. The organic fraction can be used as a blendstock or feedstock for further processing in a refinery while, in the CFP process design, the aqueous phase is currently sent to wastewater treatment, which results in a loss of residual biogenic carbon presentmore » in this stream. Our work focuses on the catalytic conversion of the biogenic carbon in pyrolysis aqueous phase streams to produce hydrocarbons using a vertical micro-reactor coupled to a molecular beam mass spectrometer (MBMS). Furthermore, the MBMS provides real-time analysis of products while also tracking catalyst deactivation. The catalyst used in this work was HZSM-5, which upgraded the oxygenated organics in the aqueous fraction to fuels comprising small olefins and aromatic hydrocarbons. During processing the aqueous bio-oil fraction the HZSM-5 catalyst exhibited higher activity and coke resistance than those observed in similar experiments using biomass or whole bio-oils. Reduced coking is likely due to ejection of coke precursors from the catalyst pores that was enhanced by excess process water available for steam stripping. The water reacted with coke precursors to form phenol, methylated phenols, naphthol, and methylated naphthols. Conversion data shows that up to 40 wt% of the carbon in the feed stream is recovered as hydrocarbons.« less
Reforming Biomass Derived Pyrolysis Bio-oil Aqueous Phase to Fuels
Mukarakate, Calvin; Evans, Robert J.; Deutch, Steve; ...
2017-01-07
Fast pyrolysis and catalytic fast pyrolysis (CFP) of biomass produce a liquid product stream comprised of various classes of organic compounds having different molecule size and polarity. This liquid, either spontaneously in the case of catalytic fast pyrolysis or by water addition for the non-catalytic process separates into a non-polar organic-rich fraction and a highly polar water-rich fraction. The organic fraction can be used as a blendstock or feedstock for further processing in a refinery while, in the CFP process design, the aqueous phase is currently sent to wastewater treatment, which results in a loss of residual biogenic carbon presentmore » in this stream. Our work focuses on the catalytic conversion of the biogenic carbon in pyrolysis aqueous phase streams to produce hydrocarbons using a vertical micro-reactor coupled to a molecular beam mass spectrometer (MBMS). Furthermore, the MBMS provides real-time analysis of products while also tracking catalyst deactivation. The catalyst used in this work was HZSM-5, which upgraded the oxygenated organics in the aqueous fraction to fuels comprising small olefins and aromatic hydrocarbons. During processing the aqueous bio-oil fraction the HZSM-5 catalyst exhibited higher activity and coke resistance than those observed in similar experiments using biomass or whole bio-oils. Reduced coking is likely due to ejection of coke precursors from the catalyst pores that was enhanced by excess process water available for steam stripping. The water reacted with coke precursors to form phenol, methylated phenols, naphthol, and methylated naphthols. Conversion data shows that up to 40 wt% of the carbon in the feed stream is recovered as hydrocarbons.« less
Dhiman, Saurabh Sudha; Shrestha, Namita; David, Aditi; Basotra, Neha; Johnson, Glenn R; Chadha, Bhupinder S; Gadhamshetty, Venkataramana; Sani, Rajesh K
2018-06-01
Residual solid and liquid streams from the one-pot CRUDE (Conversion of Raw and Untreated Disposal into Ethanol) process were treated with two separate biochemical routes for renewable energy transformation. The solid residual stream was subjected to thermophilic anaerobic digestion (TAD), which produced 95 ± 7 L methane kg -1 volatile solid with an overall energy efficiency of 12.9 ± 1.7%. A methanotroph, Methyloferula sp., was deployed for oxidation of mixed TAD biogas into methanol. The residual liquid stream from CRUDE process was used in a Microbial Fuel Cell (MFC) to produce electricity. Material balance calculations confirmed the integration of biochemical routes (i.e. CRUDE, TAD, and MFC) for developing a sustainable approach of energy regeneration. The current work demonstrates the utilization of different residual streams originated after food waste processing to release minimal organic load to the environment. Copyright © 2018 Elsevier Ltd. All rights reserved.
Technologies and Materials for Recovering Waste Heat in Harsh Environments
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nimbalkar, Sachin U.; Thekdi, Arvind; Rogers, Benjamin M.
2014-12-15
A large amount (7,204 TBtu/year) of energy is used for process heating by the manufacturing sector in the United States (US). This energy is in the form of fuels mostly natural gas with some coal or other fuels and steam generated using fuels such as natural gas, coal, by-product fuels, and some others. Combustion of these fuels results in the release of heat, which is used for process heating, and in the generation of combustion products that are discharged from the heating system. All major US industries use heating equipment such as furnaces, ovens, heaters, kilns, and dryers. The hotmore » exhaust gases from this equipment, after providing the necessary process heat, are discharged into the atmosphere through stacks. This report deals with identification of industries and industrial heating processes in which the exhaust gases are at high temperature (>1200 F), contain all of the types of reactive constituents described, and can be considered as harsh or contaminated. It also identifies specific issues related to WHR for each of these processes or waste heat streams.« less
Computational Analysis of the Combustion Processes in an Axisymmetric, RBCC Flowpath
NASA Technical Reports Server (NTRS)
Steffen, Christopher J., Jr.; Yungster, Shaye
2001-01-01
Computational fluid dynamic simulations have been used to study the combustion processes within an axisymmetric, RBCC flowpath. Two distinct operating modes have been analyzed to date, including the independent ramjet stream (IRS) cycle and the supersonic combustion ramjet (scramJet) cycle. The IRS cycle investigation examined the influence of fuel-air ratio, fuel distribution, and rocket chamber pressure upon the combustion physics and thermal choke characteristics. Results indicate that adjustment of the amount and radial distribution of fuel can control the thermal choke point. The secondary massflow rate was very sensitive to the fuel-air ratio and the rocket chamber pressure. The scramjet investigation examined the influence of fuel-air ratio and fuel injection schedule upon combustion performance estimates. An analysis of the mesh-dependence of these calculations was presented. Jet penetration data was extracted from the three-dimensional simulations and compared favorably with experimental correlations of similar flows. Results indicate that combustion efficiency was very sensitive to the fuel schedule.
NASA Astrophysics Data System (ADS)
Cao, M.-H.; Jiang, H.-K.; Chin, J.-S.
1982-04-01
An improved flat-fan spray model is used for the semi-empirical analysis of liquid fuel distribution downstream of a plain orifice injector under cross-stream air flow. The model assumes that, due to the aerodynamic force of the high-velocity cross air flow, the injected fuel immediately forms a flat-fan liquid sheet perpendicular to the cross flow. Once the droplets have been formed, the trajectories of individual droplets determine fuel distribution downstream. Comparison with test data shows that the proposed model accurately predicts liquid fuel distribution at any point downstream of a plain orifice injector under high-velocity, low-temperature uniform cross-stream air flow over a wide range of conditions.
Development of molten carbonate fuel cell technology at M-C Power Corporation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dilger, D.
1996-04-01
M-C Power Corporation was founded in 1987 with the mission to further develop and subsequently commercialize molten carbonate fuel cells (MCFC). The technology chosen for commercialization was initially developed by the Institute of Gas technology (IGT). At the center of this MCFC technology is the Internally Manifolded Heat EXchange (IMHEX) separator plate design. The IMHEX technology design provides several functions within one component assembly. These functions include integrating the gas manifold structure into the fuel cell stack, separating the fuel gas stream from the oxidant gas stream, providing the required electrical contact between cells to achieve desired power output, andmore » removing excess heat generated in the electrochemical process. Development of this MCFC technology from lab-scale sizes too a commercial area size of 1m{sup 2} has focused our efforts an demonstrating feasibility and evolutionary progress. The development effort will culminate in a proof-of-concept- 250kW power plant demonstration in 1996. The remainder of our commercialization program focuses upon lowering the costs associated with the MCFC power plant system in low production volumes.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Amoroso, J. W.; Marra, J. C.
2015-08-26
A multi-phase ceramic waste form is being developed at the Savannah River National Laboratory (SRNL) for treatment of secondary waste streams generated by reprocessing commercial spent nuclear. The envisioned waste stream contains a mixture of transition, alkali, alkaline earth, and lanthanide metals. Ceramic waste forms are tailored (engineered) to incorporate waste components as part of their crystal structure based on knowledge from naturally found minerals containing radioactive and non-radioactive species similar to the radionuclides of concern in wastes from fuel reprocessing. The ability to tailor ceramics to mimic naturally occurring crystals substantiates the long term stability of such crystals (ceramics)more » over geologic timescales of interest for nuclear waste immobilization [1]. A durable multi-phase ceramic waste form tailored to incorporate all the waste components has the potential to broaden the available disposal options and thus minimize the storage and disposal costs associated with aqueous reprocessing. This report summarizes results from three years of work on the IAEA Coordinated Research Project on “Processing technologies for high level waste, formulation of matrices and characterization of waste forms” (T21027), and specific task “Melt Processed Crystalline Ceramic Waste Forms for Advanced Nuclear Fuel Cycles” (17208).« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Amoroso, J. W.; Marra, J. C.
2015-08-26
A multi-phase ceramic waste form is being developed at the Savannah River National Laboratory (SRNL) for treatment of secondary waste streams generated by reprocessing commercial spent nuclear. The envisioned waste stream contains a mixture of transition, alkali, alkaline earth, and lanthanide metals. Ceramic waste forms are tailored (engineered) to incorporate waste components as part of their crystal structure based on knowledge from naturally found minerals containing radioactive and non-radioactive species similar to the radionuclides of concern in wastes from fuel reprocessing. The ability to tailor ceramics to mimic naturally occurring crystals substantiates the long term stability of such crystals (ceramics)more » over geologic timescales of interest for nuclear waste immobilization [1]. A durable multi-phase ceramic waste form tailored to incorporate all the waste components has the potential to broaden the available disposal options and thus minimize the storage and disposal costs associated with aqueous reprocessing. This report summarizes results from three years of work on the IAEA Coordinated Research Project on “Processing technologies for high level waste, formulation of matrices and characterization of waste forms” (T21027), and specific task “Melt Processed Crystalline Ceramic Waste Forms for Advanced Nuclear Fuel Cycles” (17208).« less
Safeguard monitoring of direct electrolytic reduction
NASA Astrophysics Data System (ADS)
Jurovitzki, Abraham L.
Nuclear power is regaining global prominence as a sustainable energy source as the world faces the consequences of depending on limited fossil based, CO2 emitting fuels. A key component to achieving this sustainability is to implement a closed nuclear fuel cycle. Without achieving this goal, a relatively small fraction of the energy value in nuclear fuel is actually utilized. This involves recycling of spent nuclear fuel (SNF)---separating fissile actinides from waste products and using them to fabricate fresh fuel. Pyroprocessing is a viable option being developed for this purpose with a host of benefits compared to other recycling options, such as PUREX. Notably, pyroprocessing is ill suited to separate pure plutonium from spent fuel and thus has non-proliferation benefits. Pyroprocessing involves high temperature electrochemical and chemical processing of SNF in a molten salt electrolyte. During this batch process, several intermediate and final streams are produced that contain radioactive material. While pyroprocessing is ineffective at separating pure plutonium, there are various process misuse scenarios that could result in diversion of impure plutonium into one or more of these streams. This is a proliferation risk that should be addressed with innovative safeguards technology. One approach to meeting this challenge is to develop real time monitoring techniques that can be implemented in the hot cells and coupled with the various unit operations involved with pyroprocessing. Current state of the art monitoring techniques involve external chemical assaying which requires sample removal from these unit operations. These methods do not meet International Atomic Energy Agency's (IAEA) timeliness requirements. In this work, a number of monitoring techniques were assessed for their viability as online monitoring tools. A hypothetical diversion scenario for the direct electrolytic reduction process was experimentally verified (using Nd2O3 as a surrogate for PuO2). Electrochemical analysis was demonstrated to be effective at detecting even very dilute concentrations of actinides as evidence for a diversion attempt.
Fuel Cell/Reformers Technology Development
NASA Technical Reports Server (NTRS)
2004-01-01
NASA Glenn Research Center is interested in developing Solid Oxide Fuel Cell for use in aerospace applications. Solid oxide fuel cell requires hydrogen rich feed stream by converting commercial aviation jet fuel in a fuel processing process. The grantee's primary research activities center on designing and constructing a test facility for evaluating injector concepts to provide optimum feeds to fuel processor; collecting and analyzing literature information on fuel processing and desulfurization technologies; establishing industry and academic contacts in related areas; providing technical support to in-house SOFC-based system studies. Fuel processing is a chemical reaction process that requires efficient delivery of reactants to reactor beds for optimum performance, i.e., high conversion efficiency and maximum hydrogen production, and reliable continuous operation. Feed delivery and vaporization quality can be improved by applying NASA's expertise in combustor injector design. A 10 KWe injector rig has been designed, procured, and constructed to provide a tool to employ laser diagnostic capability to evaluate various injector concepts for fuel processing reactor feed delivery application. This injector rig facility is now undergoing mechanical and system check-out with an anticipated actual operation in July 2004. Multiple injector concepts including impinging jet, venturi mixing, discrete jet, will be tested and evaluated with actual fuel mixture compatible with reforming catalyst requirement. Research activities from September 2002 to the closing of this collaborative agreement have been in the following areas: compiling literature information on jet fuel reforming; conducting autothermal reforming catalyst screening; establishing contacts with other government agencies for collaborative research in jet fuel reforming and desulfurization; providing process design basis for the build-up of injector rig facility and individual injector design.
Liquid-Feed Methanol Fuel Cell With Membrane Electrolyte
NASA Technical Reports Server (NTRS)
Surampudi, Subbarao; Narayanan, S. R.; Halpert, Gerald; Frank, Harvey; Vamos, Eugene
1995-01-01
Fuel cell generates electricity from direct liquid feed stream of methanol/water solution circulated in contact with anode, plus direct gaseous feed stream of air or oxygen in contact with cathode. Advantages include relative simplicity and elimination of corrosive electrolytic solutions. Offers potential for reductions in size, weight, and complexity, and for increases in safety of fuel-cell systems.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rizeq, George; West, Janice; Frydman, Arnaldo
Electricity produced from hydrogen in fuel cells can be highly efficient relative to competing technologies and has the potential to be virtually pollution free. Thus, fuel cells may become an ideal solution to this nation's energy needs if one has a satisfactory process for producing hydrogen from available energy resources such as coal, and low-cost alternative feedstocks such as biomass. GE EER is developing an innovative fuel-flexible advanced gasification-combustion (AGC) technology for production of hydrogen for fuel cells or combustion turbines, and a separate stream of sequestration-ready CO2. The AGC module can be integrated into a number of Vision- 21more » power systems. It offers increased energy efficiency relative to conventional gasification and combustion systems and near-zero pollution. The R&D on the AGC technology is being conducted under a Vision-21 award from the U.S. DOE NETL with co-funding from GE EER, Southern Illinois University at Carbondale (SIU-C), and the California Energy Commission (CEC). The AGC technology converts coal and air into three separate streams of pure hydrogen, sequestration-ready CO2, and high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The three-year program integrates lab-, bench- and pilot-scale studies to demonstrate the AGC concept. Process and kinetic modeling studies as well as an economic assessment will also be performed. This paper provides an overview of the program and its objectives, and discusses first-year R&D activities, including design of experimental facilities and results from initial tests and modeling studies. In particular, the paper describes the design of the bench-scale facility and initial process modeling data. In addition, a process flow diagram is shown for a complete plant incorporating the AGC module with other Vision-21 plant components to maximize hydrogen production and process efficiency.« less
Energy efficiency and greenhouse gas emission intensity of petroleum products at U.S. refineries.
Elgowainy, Amgad; Han, Jeongwoo; Cai, Hao; Wang, Michael; Forman, Grant S; DiVita, Vincent B
2014-07-01
This paper describes the development of (1) a formula correlating the variation in overall refinery energy efficiency with crude quality, refinery complexity, and product slate; and (2) a methodology for calculating energy and greenhouse gas (GHG) emission intensities and processing fuel shares of major U.S. refinery products. Overall refinery energy efficiency is the ratio of the energy present in all product streams divided by the energy in all input streams. Using linear programming (LP) modeling of the various refinery processing units, we analyzed 43 refineries that process 70% of total crude input to U.S. refineries and cover the largest four Petroleum Administration for Defense District (PADD) regions (I, II, III, V). Based on the allocation of process energy among products at the process unit level, the weighted-average product-specific energy efficiencies (and ranges) are estimated to be 88.6% (86.2%-91.2%) for gasoline, 90.9% (84.8%-94.5%) for diesel, 95.3% (93.0%-97.5%) for jet fuel, 94.5% (91.6%-96.2%) for residual fuel oil (RFO), and 90.8% (88.0%-94.3%) for liquefied petroleum gas (LPG). The corresponding weighted-average, production GHG emission intensities (and ranges) (in grams of carbon dioxide-equivalent (CO2e) per megajoule (MJ)) are estimated to be 7.8 (6.2-9.8) for gasoline, 4.9 (2.7-9.9) for diesel, 2.3 (0.9-4.4) for jet fuel, 3.4 (1.5-6.9) for RFO, and 6.6 (4.3-9.2) for LPG. The findings of this study are key components of the life-cycle assessment of GHG emissions associated with various petroleum fuels; such assessment is the centerpiece of legislation developed and promulgated by government agencies in the United States and abroad to reduce GHG emissions and abate global warming.
2014-08-01
of alcohols with LanzaTech’s unique gas fermentation process for converting waste gas streams to ethanol. The alcohol conversion process begins with...grain/wood being converted to sugar followed by fermentation into a mixture of C2-C5 alcohols. These are then converted to a mixture of C4-C20...produce farnesene by fermentation of sugar feedstocks. Farnesene is then converted to farnesane through a combination of hydroprocessing and
Hydrodynamic Suppression of Soot Formation in Laminar Coflowing Jet Diffusion Flames. Appendix C
NASA Technical Reports Server (NTRS)
Dai, Z.; Faeth, G. M.; Yuan, Z.-G. (Technical Monitor); Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)
2000-01-01
Effects of flow (hydrodynamic) properties on limiting conditions for soot-free laminar non-premixed hydrocarbon/air flames (called laminar soot-point conditions) were studied, emphasizing non-buoyant laminar coflowing jet diffusion flames. Effects of air/fuel-stream velocity ratios were of particular interest; therefore, the experiments were carried out at reduced pressures to minimize effects of flow acceleration due to the intrusion of buoyancy. Test conditions included reactant temperatures of 300 K; ambient pressures of 3.7-49 8 kPa; methane-, acetylene-, ethylene-, propane-, and methane-fueled flames burning in coflowing air with fuel-port diameters of 1.7, 3.2, and 6.4 mm, fuel jet Reynolds numbers of 18-121; air coflow velocities of 0-6 m/s; and air/fuel-stream velocity ratios of 0.003-70. Measurements included laminar soot-point flame lengths, laminar soot-point fuel flow rates, and laminar liftoff conditions. The measurements show that laminar soot-point flame lengths and fuel flow rates can be increased, broadening the range of fuel flow rates where the flames remain soot free, by increasing air/fuel-stream velocity ratios. The mechanism of this effect involves the magnitude and direction of flow velocities relative to the flame sheet where increased air/fuel-stream velocity ratios cause progressive reduction of flame residence times in the fuel-rich soot-formation region. The range of soot-free conditions is limited by both liftoff, particularly at low pressures, and the intrusion of effects of buoyancy on effective air/fuel-stream velocity ratios, particularly at high pressures. Effective correlations of laminar soot- and smoke-point flame lengths were also found in terms of a corrected fuel flow rate parameter, based on simplified analysis of laminar jet diffusion flame structure. The results show that laminar smoke-point flame lengths in coflowing air environments are roughly twice as long as soot-free (blue) flames under comparable conditions due to the presence of luminous soot particles under fuel-lean conditions when smoke-point conditions are approached. This is very similar to earlier findings concerning differences between laminar smoke- and sootpoint flame lengths in still environments.
Fossil fuel combined cycle power system
Labinov, Solomon Davidovich; Armstrong, Timothy Robert; Judkins, Roddie Reagan
2006-10-10
A system for converting fuel energy to electricity includes a reformer for converting a higher molecular weight gas into at least one lower molecular weight gas, at least one turbine to produce electricity from expansion of at least one of the lower molecular weight gases, and at least one fuel cell. The system can further include at least one separation device for substantially dividing the lower molecular weight gases into at least two gas streams prior to the electrochemical oxidization step. A nuclear reactor can be used to supply at least a portion of the heat the required for the chemical conversion process.
Mobil cuts the alcohol out of oxygenate production
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wood, A.
1992-04-15
Mobil Corp. has unveiled a new etherification technology that can produce fuel oxygenated based only on olefinic refinery streams and water. The process has the potential to allow refiners to produce oxygenates without having to rely on an external supply of alcohols such as methanol or ethanol. Mobil has developed the technology around a new oxygenate, disopropyl ether (DIPE), based on propylene. However, the process has also been tested using mixed propylene/C{sub 4} and straight C{sub 4} streams, says Michael J. McNally, manager of Mobil`s Motor Gasoline Group (Paulsboro, NJ), producing ethers analogous to methyl tert-butyl ether (MTBE).
Coprocessed nuclear fuels containing (U, Pu) values as oxides, carbides or carbonitrides
Lloyd, M.H.
1981-01-09
Method for direct coprocessing of nuclear fuels derived from a product stream of fuels reprocessing facility containing uranium, plutonium, and fission product values comprising nitrate stabilization of said stream vacuum concentration to remove water and nitrates, neutralization to form an acid deficient feed solution for the internal gelation mode of sol-gel technology, green spherule formation, recovery and treatment for loading into a fuel element by vibra packed or pellet formation technologies.
Coprocessed nuclear fuels containing (U, Pu) values as oxides, carbides or carbonitrides
Lloyd, Milton H.
1983-01-01
Method for direct coprocessing of nuclear fuels derived from a product stream of a fuels reprocessing facility containing uranium, plutonium, and fission product values comprising nitrate stabilization of said stream vacuum concentration to remove water and nitrates, neutralization to form an acid deficient feed solution for the internal gelation mode of sol-gel technology, green spherule formation, recovery and treatment for loading into a fuel element by vibra packed or pellet formation technologies.
Mechanisms and kinetics of granulated sewage sludge combustion.
Kijo-Kleczkowska, Agnieszka; Środa, Katarzyna; Kosowska-Golachowska, Monika; Musiał, Tomasz; Wolski, Krzysztof
2015-12-01
This paper investigates sewage sludge disposal methods with particular emphasis on combustion as the priority disposal method. Sewage sludge incineration is an attractive option because it minimizes odour, significantly reduces the volume of the starting material and thermally destroys organic and toxic components of the off pads. Additionally, it is possible that ashes could be used. Currently, as many as 11 plants use sewage sludge as fuel in Poland; thus, this technology must be further developed in Poland while considering the benefits of co-combustion with other fuels. This paper presents the results of experimental studies aimed at determining the mechanisms (defining the fuel combustion region by studying the effects of process parameters, including the size of the fuel sample, temperature in the combustion chamber and air velocity, on combustion) and kinetics (measurement of fuel temperature and mass changes) of fuel combustion in an air stream under different thermal conditions and flow rates. The combustion of the sludge samples during air flow between temperatures of 800 and 900°C is a kinetic-diffusion process. This process determines the sample size, temperature of its environment, and air velocity. The adopted process parameters, the time and ignition temperature of the fuel by volatiles, combustion time of the volatiles, time to reach the maximum temperature of the fuel surface, maximum temperature of the fuel surface, char combustion time, and the total process time, had significant impacts. Copyright © 2015 Elsevier Ltd. All rights reserved.
Combustor air flow control method for fuel cell apparatus
Clingerman, Bruce J.; Mowery, Kenneth D.; Ripley, Eugene V.
2001-01-01
A method for controlling the heat output of a combustor in a fuel cell apparatus to a fuel processor where the combustor has dual air inlet streams including atmospheric air and fuel cell cathode effluent containing oxygen depleted air. In all operating modes, an enthalpy balance is provided by regulating the quantity of the air flow stream to the combustor to support fuel cell processor heat requirements. A control provides a quick fast forward change in an air valve orifice cross section in response to a calculated predetermined air flow, the molar constituents of the air stream to the combustor, the pressure drop across the air valve, and a look up table of the orifice cross sectional area and valve steps. A feedback loop fine tunes any error between the measured air flow to the combustor and the predetermined air flow.
Mueller, Charles J.; Cannella, William J.; Bruno, Thomas J.; ...
2012-05-22
In this study, a novel approach was developed to formulate surrogate fuels having characteristics that are representative of diesel fuels produced from real-world refinery streams. Because diesel fuels typically consist of hundreds of compounds, it is difficult to conclusively determine the effects of fuel composition on combustion properties. Surrogate fuels, being simpler representations of these practical fuels, are of interest because they can provide a better understanding of fundamental fuel-composition and property effects on combustion and emissions-formation processes in internal-combustion engines. In addition, the application of surrogate fuels in numerical simulations with accurate vaporization, mixing, and combustion models could revolutionizemore » future engine designs by enabling computational optimization for evolving real fuels. Dependable computational design would not only improve engine function, it would do so at significant cost savings relative to current optimization strategies that rely on physical testing of hardware prototypes. The approach in this study utilized the state-of-the-art techniques of 13C and 1H nuclear magnetic resonance spectroscopy and the advanced distillation curve to characterize fuel composition and volatility, respectively. The ignition quality was quantified by the derived cetane number. Two well-characterized, ultra-low-sulfur #2 diesel reference fuels produced from refinery streams were used as target fuels: a 2007 emissions certification fuel and a Coordinating Research Council (CRC) Fuels for Advanced Combustion Engines (FACE) diesel fuel. A surrogate was created for each target fuel by blending eight pure compounds. The known carbon bond types within the pure compounds, as well as models for the ignition qualities and volatilities of their mixtures, were used in a multiproperty regression algorithm to determine optimal surrogate formulations. The predicted and measured surrogate-fuel properties were quantitatively compared to the measured target-fuel properties, and good agreement was found.« less
Low NOx combustion using cogenerated oxygen and nitrogen streams
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kobayashi, Hisashi; Bool, Lawrence E; Snyder, William J
Combustion of hydrocarbon fuel is achieved with less formation of NOx by feeding the fuel into a slightly oxygen-enriched atmosphere, and separating air into oxygen-rich and nitrogen-rich streams which are fed separately into the combustion device.
Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne
2014-08-01
This paper presents the mass, energy and material balances of a solid recovered fuel (SRF) production process. The SRF is produced from commercial and industrial waste (C&IW) through mechanical treatment (MT). In this work various streams of material produced in SRF production process are analyzed for their proximate and ultimate analysis. Based on this analysis and composition of process streams their mass, energy and material balances are established for SRF production process. Here mass balance describes the overall mass flow of input waste material in the various output streams, whereas material balance describes the mass flow of components of input waste stream (such as paper and cardboard, wood, plastic (soft), plastic (hard), textile and rubber) in the various output streams of SRF production process. A commercial scale experimental campaign was conducted on an MT waste sorting plant to produce SRF from C&IW. All the process streams (input and output) produced in this MT plant were sampled and treated according to the CEN standard methods for SRF: EN 15442 and EN 15443. The results from the mass balance of SRF production process showed that of the total input C&IW material to MT waste sorting plant, 62% was recovered in the form of SRF, 4% as ferrous metal, 1% as non-ferrous metal and 21% was sorted out as reject material, 11.6% as fine fraction, and 0.4% as heavy fraction. The energy flow balance in various process streams of this SRF production process showed that of the total input energy content of C&IW to MT plant, 75% energy was recovered in the form of SRF, 20% belonged to the reject material stream and rest 5% belonged with the streams of fine fraction and heavy fraction. In the material balances, mass fractions of plastic (soft), plastic (hard), paper and cardboard and wood recovered in the SRF stream were 88%, 70%, 72% and 60% respectively of their input masses to MT plant. A high mass fraction of plastic (PVC), rubber material and non-combustibles (such as stone/rock and glass particles), was found in the reject material stream. Copyright © 2014 Elsevier Ltd. All rights reserved.
K basins sludge removal sludge pretreatment system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chang, H.L.
1997-06-12
The Spent Nuclear Fuels Program is in the process of planning activities to remove spent nuclear fuel and other materials from the 100-K Basins as a remediation effort for clean closure. The 105 K- East and K-West Basins store spent fuel, sludge, and debris. Sludge has accumulated in the 1 00 K Basins as a result of fuel oxidation and a slight amount of general debris being deposited, by settling, in the basin water. The ultimate intent in removing the sludge and fuel is to eliminate the environmental risk posed by storing fuel at the K Basins. The task formore » this project is to disposition specific constituents of sludge (metallic fuel) to produce a product stream through a pretreatment process that will meet the requirements, including a final particle size acceptable to the Tank Waste Remediation System (TWRS). The purpose of this task is to develop a preconceptual design package for the K Basin sludge pretreatment system. The process equipment/system is at a preconceptual stage, as shown in sketch ES-SNF-01 , while a more refined process system and material/energy balances are ongoing (all sketches are shown in Appendix C). Thus, the overall process and 0535 associated equipment have been conservatively selected and sized, respectively, to establish the cost basis and equipment layout as shown in sketches ES- SNF-02 through 08.« less
Functional mathematical model of a hydrogen-driven combustion chamber for a scramjet
NASA Astrophysics Data System (ADS)
Latypov, A. F.
2015-09-01
A functional mathematical model of a hydrogen-driven combustion chamber for a scramjet is described. The model is constructed with the use of one-dimensional steady gas-dynamic equations and parametrization of the channel configuration and the governing parameters (fuel injection into the flow, fuel burnout along the channel, dissipation of kinetic energy, removal of some part of energy generated by gases for modeling cooling of channel walls by the fuel) with allowance for real thermophysical properties of the gases. Through parametric calculations, it is found that fuel injection in three cross sections of the channel consisting of segments with weak and strong expansion ensures a supersonic velocity of combustion products in the range of free-stream Mach numbers M∞ = 6-12. It is demonstrated that the angle between the velocity vectors of the gaseous hydrogen flow and the main gas flow can be fairly large in the case of distributed injection of the fuel. This allows effective control of the mixing process. It is proposed to use the exergy of combustion products as a criterion of the efficiency of heat supply in the combustion chamber. Based on the calculated values of exergy, the critical free-stream Mach number that still allows scramjet operation is estimated.
Evaluation of a Zirconium Recycle Scrubber System
DOE Office of Scientific and Technical Information (OSTI.GOV)
Spencer, Barry B.; Bruffey, Stephanie H.
2017-04-01
A hot-cell demonstration of the zirconium recycle process is planned as part of the Materials Recovery and Waste Forms Development (MRWFD) campaign. The process treats Zircaloy® cladding recovered from used nuclear fuel with chlorine gas to recover the zirconium as volatile ZrCl4. This releases radioactive tritium trapped in the alloy, converting it to volatile tritium chloride (TCl). To meet regulatory requirements governing radioactive emissions from nuclear fuel treatment operations, the capture and retention of a portion of this TCl may be required prior to discharge of the off-gas stream to the environment. In addition to demonstrating tritium removal from amore » synthetic zirconium recycle off-gas stream, the recovery and quantification of tritium may refine estimates of the amount of tritium present in the Zircaloy cladding of used nuclear fuel. To support these objectives, a bubbler-type scrubber was fabricated to remove the TCl from the zirconium recycle off-gas stream. The scrubber was fabricated from glass and polymer components that are resistant to chlorine and hydrochloric acid solutions. Because of concerns that the scrubber efficiency is not quantitative, tests were performed using DCl as a stand-in to experimentally measure the scrubbing efficiency of this unit. Scrubbing efficiency was ~108% ± 3% with water as the scrubber solution. Variations were noted when 1 M NaOH scrub solution was used, values ranged from 64% to 130%. The reason for the variations is not known. It is recommended that the equipment be operated with water as the scrubbing solution. Scrubbing efficiency is estimated at 100%.« less
Interim waste storage for the Integral Fast Reactor
DOE Office of Scientific and Technical Information (OSTI.GOV)
Benedict, R.W.; Phipps, R.D.; Condiff, D.W.
1991-01-01
The Integral Fast Reactor (IFR), which Argonne National Laboratory is developing, is an innovative liquid metal breeder reactor that uses metallic fuel and has a close coupled fuel recovery process. A pyrochemical process is used to separate the fission products from the actinide elements. These actinides are used to make new fuel for the reactor. As part of the overall IFR development program, Argonne has refurbished an existing Fuel Cycle Facility at ANL-West and is installing new equipment to demonstrate the remote reprocessing and fabrication of fuel for the Experimental Breeder Reactor II (EBR-II). During this demonstration the wastes thatmore » are produced will be treated and packaged to produce waste forms that would be typical of future commercial operations. These future waste forms would, assuming Argonne development goals are fulfilled, be essentially free of long half-life transuranic isotopes. Promising early results indicate that actinide extraction processes can be developed to strip these isotopes from waste stream and return them to the IFR type reactors for fissioning. 1 fig.« less
A Characteristics-Based Approach to Radioactive Waste Classification in Advanced Nuclear Fuel Cycles
NASA Astrophysics Data System (ADS)
Djokic, Denia
The radioactive waste classification system currently used in the United States primarily relies on a source-based framework. This has lead to numerous issues, such as wastes that are not categorized by their intrinsic risk, or wastes that do not fall under a category within the framework and therefore are without a legal imperative for responsible management. Furthermore, in the possible case that advanced fuel cycles were to be deployed in the United States, the shortcomings of the source-based classification system would be exacerbated: advanced fuel cycles implement processes such as the separation of used nuclear fuel, which introduce new waste streams of varying characteristics. To be able to manage and dispose of these potential new wastes properly, development of a classification system that would assign appropriate level of management to each type of waste based on its physical properties is imperative. This dissertation explores how characteristics from wastes generated from potential future nuclear fuel cycles could be coupled with a characteristics-based classification framework. A static mass flow model developed under the Department of Energy's Fuel Cycle Research & Development program, called the Fuel-cycle Integration and Tradeoffs (FIT) model, was used to calculate the composition of waste streams resulting from different nuclear fuel cycle choices: two modified open fuel cycle cases (recycle in MOX reactor) and two different continuous-recycle fast reactor recycle cases (oxide and metal fuel fast reactors). This analysis focuses on the impact of waste heat load on waste classification practices, although future work could involve coupling waste heat load with metrics of radiotoxicity and longevity. The value of separation of heat-generating fission products and actinides in different fuel cycles and how it could inform long- and short-term disposal management is discussed. It is shown that the benefits of reducing the short-term fission-product heat load of waste destined for geologic disposal are neglected under the current source-based radioactive waste classification system, and that it is useful to classify waste streams based on how favorable the impact of interim storage is on increasing repository capacity. The need for a more diverse set of waste classes is discussed, and it is shown that the characteristics-based IAEA classification guidelines could accommodate wastes created from advanced fuel cycles more comprehensively than the U.S. classification framework.
Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne
2014-11-01
In this work, the fraction of construction and demolition waste (C&D waste) complicated and economically not feasible to sort out for recycling purposes is used to produce solid recovered fuel (SRF) through mechanical treatment (MT). The paper presents the mass, energy and material balances of this SRF production process. All the process streams (input and output) produced in MT waste sorting plant to produce SRF from C&D waste are sampled and treated according to CEN standard methods for SRF. Proximate and ultimate analysis of these streams is performed and their composition is determined. Based on this analysis and composition of process streams their mass, energy and material balances are established for SRF production process. By mass balance means the overall mass flow of input waste material stream in the various output streams and material balances mean the mass flow of components of input waste material stream (such as paper and cardboard, wood, plastic (soft), plastic (hard), textile and rubber) in the various output streams of SRF production process. The results from mass balance of SRF production process showed that of the total input C&D waste material to MT waste sorting plant, 44% was recovered in the form of SRF, 5% as ferrous metal, 1% as non-ferrous metal, and 28% was sorted out as fine fraction, 18% as reject material and 4% as heavy fraction. The energy balance of this SRF production process showed that of the total input energy content of C&D waste material to MT waste sorting plant, 74% was recovered in the form of SRF, 16% belonged to the reject material and rest 10% belonged to the streams of fine fraction and heavy fraction. From the material balances of this process, mass fractions of plastic (soft), paper and cardboard, wood and plastic (hard) recovered in the SRF stream were 84%, 82%, 72% and 68% respectively of their input masses to MT plant. A high mass fraction of plastic (PVC) and rubber material was found in the reject material stream. Streams of heavy fraction and fine fraction mainly contained non-combustible material (such as stone/rock, sand particles and gypsum material). Copyright © 2014 Elsevier Ltd. All rights reserved.
Subtask 3.9 - Direct Coal Liquefaction Process Development
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aulich, Ted; Sharma, Ramesh
The Energy and Environmental Research Center (EERC), in partnership with the U.S. Department of Energy (DOE) and Accelergy Corporation, an advanced fuels developer with technologies exclusively licensed from ExxonMobil, undertook Subtask 3.9 to design, build, and preliminarily operate a bench-scale direct coal liquefaction (DCL) system capable of converting 45 pounds/hour of pulverized, dried coal to a liquid suitable for upgrading to fuels and/or chemicals. Fabrication and installation of the DCL system and an accompanying distillation system for off-line fractionation of raw coal liquids into 1) a naphtha middle distillate stream for upgrading and 2) a recycle stream was completed inmore » May 2012. Shakedown of the system was initiated in July 2012. In addition to completing fabrication of the DCL system, the project also produced a 500-milliliter sample of jet fuel derived in part from direct liquefaction of Illinois No. 6 coal, and submitted the sample to the Air Force Research Laboratory (AFRL) at Wright Patterson Air Force Base, Dayton, Ohio, for evaluation. The sample was confirmed by AFRL to be in compliance with all U.S. Air Force-prescribed alternative aviation fuel initial screening criteria.« less
High performance, high density hydrocarbon fuels
NASA Technical Reports Server (NTRS)
Frankenfeld, J. W.; Hastings, T. W.; Lieberman, M.; Taylor, W. F.
1978-01-01
The fuels were selected from 77 original candidates on the basis of estimated merit index and cost effectiveness. The ten candidates consisted of 3 pure compounds, 4 chemical plant streams and 3 refinery streams. Critical physical and chemical properties of the candidate fuels were measured including heat of combustion, density, and viscosity as a function of temperature, freezing points, vapor pressure, boiling point, thermal stability. The best all around candidate was found to be a chemical plant olefin stream rich in dicyclopentadiene. This material has a high merit index and is available at low cost. Possible problem areas were identified as low temperature flow properties and thermal stability. An economic analysis was carried out to determine the production costs of top candidates. The chemical plant and refinery streams were all less than 44 cent/kg while the pure compounds were greater than 44 cent/kg. A literature survey was conducted on the state of the art of advanced hydrocarbon fuel technology as applied to high energy propellents. Several areas for additional research were identified.
PEM fuel cell bipolar plate material requirements for transportation applications
DOE Office of Scientific and Technical Information (OSTI.GOV)
Borup, R.L.; Stroh, K.R.; Vanderborgh, N.E.
1996-04-01
Cost effective bipolar plates are currently under development to help make proton exchange membrane (PEM) fuel cells commercially viable. Bipolar plates separate individual cells of the fuel cell stack, and thus must supply strength, be electrically conductive, provide for thermal control of the fuel stack, be a non-porous materials separating hydrogen and oxygen feed streams, be corrosion resistant, provide gas distribution for the feed streams and meet fuel stack cost targets. Candidate materials include conductive polymers and metal plates with corrosion resistant coatings. Possible metals include aluminium, titanium, iron/stainless steel and nickel.
40 CFR 60.705 - Reporting and recordkeeping requirements.
Code of Federal Regulations, 2011 CFR
2011-07-01
... Volatile Organic Compound Emissions From Synthetic Organic Chemical Manufacturing Industry (SOCMI) Reactor... used or where the reactor process vent stream is introduced as the primary fuel to any size boiler or... equipment or reactors; (2) Any recalculation of the TRE index value performed pursuant to § 60.704(f); and...
40 CFR 60.705 - Reporting and recordkeeping requirements.
Code of Federal Regulations, 2010 CFR
2010-07-01
... Volatile Organic Compound Emissions From Synthetic Organic Chemical Manufacturing Industry (SOCMI) Reactor... used or where the reactor process vent stream is introduced as the primary fuel to any size boiler or... equipment or reactors; (2) Any recalculation of the TRE index value performed pursuant to § 60.704(f); and...
USDA-ARS?s Scientific Manuscript database
Fundamental understanding of biomass pretreatment and its influence on sacchrification kinetics, total sugar yield, and inhibitor formation is essential to develop efficient next-generation biofuels strategies, capable of displacing fossil fuels at a commercial level. In this study we investigate t...
Code of Federal Regulations, 2010 CFR
2010-07-01
... provided by the primary fuel. Total organic compounds or TOC means those compounds measured according to...), and TOC concentration as required in § 60.705(b)(4) and § 60.705(f)(4), those compounds which the... per unit reduction of TOC associated with a vent stream from an affected reactor process facility...
40 CFR 65.163 - Other records.
Code of Federal Regulations, 2011 CFR
2011-07-01
...) Detailed schematics, design specifications of the control device, and piping and instrumentation diagrams... FEDERAL AIR RULE Closed Vent Systems, Control Devices, and Routing to a Fuel Gas System or a Process § 65... bypass lines that could divert a vent stream away from the control device and to the atmosphere, the...
40 CFR 63.8698 - What definitions apply to this subpart?
Code of Federal Regulations, 2011 CFR
2011-07-01
... means an enclosed combustion device that primarily transfers heat liberated by burning fuel directly to process streams or to heat transfer liquids other than water. Research and development equipment means any... facility used to transfer oxidized asphalt from a storage tank into a tank truck, rail car, or barge...
Fuel cell electric power production
Hwang, Herng-Shinn; Heck, Ronald M.; Yarrington, Robert M.
1985-01-01
A process for generating electricity from a fuel cell includes generating a hydrogen-rich gas as the fuel for the fuel cell by treating a hydrocarbon feed, which may be a normally liquid feed, in an autothermal reformer utilizing a first monolithic catalyst zone having palladium and platinum catalytic components therein and a second, platinum group metal steam reforming catalyst. Air is used as the oxidant in the hydrocarbon reforming zone and a low oxygen to carbon ratio is maintained to control the amount of dilution of the hydrogen-rich gas with nitrogen of the air without sustaining an insupportable amount of carbon deposition on the catalyst. Anode vent gas may be utilized as the fuel to preheat the inlet stream to the reformer. The fuel cell and the reformer are preferably operated at elevated pressures, up to about a pressure of 150 psia for the fuel cell.
Thermally efficient melting for glass making
Chen, Michael S. K.; Painter, Corning F.; Pastore, Steven P.; Roth, Gary; Winchester, David C.
1991-01-01
The present invention is an integrated process for the production of glass utilizing combustion heat to melt glassmaking materials in a glassmaking furnace. The fuel combusted to produce heat sufficient to melt the glassmaking materials is combusted with oxygen-enriched oxidant to reduce heat losses from the offgas of the glassmaking furnace. The process further reduces heat losses by quenching hot offgas from the glassmaking furnace with a process stream to retain the heat recovered from quench in the glassmaking process with subsequent additional heat recovery by heat exchange of the fuel to the glassmaking furnace, as well as the glassmaking materials, such as batch and cullet. The process includes recovery of a commercially pure carbon dioxide product by separatory means from the cooled, residual offgas from the glassmaking furnace.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Taylor, Curtis; Patterson, Brad; Perdue, Jayson
A burner assembly combines oxygen and fuel to produce a flame. The burner assembly includes an oxygen supply tube adapted to receive a stream of oxygen and a solid fuel conduit arranged to extend through the oxygen tube to convey a stream of fluidized, pulverized, solid fuel into a flame chamber. Oxygen flowing through the oxygen supply tube passes generally tangentially through a first set of oxygen-injection holes formed in the solid fuel conduit and off-tangentially from a second set of oxygen-injection holes formed in the solid fuel conduit and then mixes with fluidized, pulverized, solid fuel passing through themore » solid fuel conduit to create an oxygen-fuel mixture in a downstream portion of the solid fuel conduit. This mixture is discharged into a flame chamber and ignited in the flame chamber to produce a flame.« less
Jet fuel based high pressure solid oxide fuel cell system
NASA Technical Reports Server (NTRS)
Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Bayt, Robert (Inventor); Srinivasan, Hari (Inventor); Dasgupta, Arindam (Inventor); Hardin, Larry (Inventor)
2013-01-01
A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.
Jet Fuel Based High Pressure Solid Oxide Fuel Cell System
NASA Technical Reports Server (NTRS)
Srinivasan, Hari (Inventor); Hardin, Larry (Inventor); Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Dasgupta, Arindam (Inventor); Bayt, Robert (Inventor)
2015-01-01
A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.
Algal Energy Conversion and Capture
NASA Astrophysics Data System (ADS)
Hazendonk, P.
2015-12-01
We address the potential for energy conversions and capture for: energy generation; reduction in energy use; reduction in greenhouse gas emissions; remediation of water and air pollution; protection and enhancement of soil fertility. These processes have the potential to sequester carbon at scales that may have global impact. Energy conversion and capture strategies evaluate energy use and production from agriculture, urban areas and industries, and apply existing and emerging technologies to reduce and recapture energy embedded in waste products. The basis of biocrude production from Micro-algal feedstocks: 1) The nutrients from the liquid fraction of waste streams are concentrated and fed into photo bioreactors (essentially large vessels in which microalgae are grown) along with CO2 from flue gasses from down stream processes. 2) The algae are processed to remove high value products such as proteins and beta-carotenes. The advantage of algae feedstocks is the high biomass productivity is 30-50 times that of land based crops and the remaining biomass contains minimal components that are difficult to convert to biocrude. 3) The remaining biomass undergoes hydrothermal liquefaction to produces biocrude and biochar. The flue gasses of this process can be used to produce electricity (fuel cell) and subsequently fed back into the photobioreactor. The thermal energy required for this process is small, hence readily obtained from solar-thermal sources, and furthermore no drying or preprocessing is required keeping the energy overhead extremely small. 4) The biocrude can be upgraded and refined as conventional crude oil, creating a range of liquid fuels. In principle this process can be applied on the farm scale to the municipal scale. Overall, our primary food production is too dependent on fossil fuels. Energy conversion and capture can make food production sustainable.
Fuel cell membrane hydration and fluid metering
Jones, Daniel O.; Walsh, Michael M.
1999-01-01
A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel in order to mix its respective portion of liquid water with the corresponding portion of the stream. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).
SPECTROSCOPIC ONLINE MONITORING FOR PROCESS CONTROL AND SAFEGUARDING OF RADIOCHEMICAL STREAMS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bryan, Samuel A.; Levitskaia, Tatiana G.
2013-09-29
There is a renewed interest worldwide to promote the use of nuclear power and close the nuclear fuel cycle. The long term successful use of nuclear power is critically dependent upon adequate and safe processing and disposition of the used nuclear fuel. Liquid-liquid extraction is a separation technique commonly employed for the processing of the dissolved used nuclear fuel. The instrumentation used to monitor these processes must be robust, require little or no maintenance, and be able to withstand harsh environments such as high radiation fields and aggressive chemical matrices. This paper summarizes application of the absorption and vibrational spectroscopicmore » techniques supplemented by physicochemical measurements for radiochemical process monitoring. In this context, our team experimentally assessed the potential of Raman and spectrophotometric techniques for online real-time monitoring of the U(VI)/nitrate ion/nitric acid and Pu(IV)/Np(V)/Nd(III), respectively, in solutions relevant to spent fuel reprocessing. These techniques demonstrate robust performance in the repetitive batch measurements of each analyte in a wide concentration range using simulant and commercial dissolved spent fuel solutions. Spectroscopic measurements served as training sets for the multivariate data analysis to obtain partial least squares predictive models, which were validated using on-line centrifugal contactor extraction tests. Satisfactory prediction of the analytes concentrations in these preliminary experiments warrants further development of the spectroscopy-based methods for radiochemical process control and safeguarding. Additionally, the ability to identify material intentionally diverted from a liquid-liquid extraction contactor system was successfully tested using on-line process monitoring as a means to detect the amount of material diverted. A chemical diversion and detection from a liquid-liquid extraction scheme was demonstrated using a centrifugal contactor system operating with the simulant PUREX extraction system of Nd(NO3)3/nitric acid aqueous phase and TBP/n-dodecane organic phase. During a continuous extraction experiment, a portion of the feed from a counter-current extraction system was diverted while the spectroscopic on-line process monitoring system was simultaneously measuring the feed, raffinate and organic products streams. The amount observed to be diverted by on-line spectroscopic process monitoring was in excellent agreement with values based from the known mass of sample directly taken (diverted) from system feed solution.« less
Design and control of a variable geometry turbofan with an independently modulated third stream
NASA Astrophysics Data System (ADS)
Simmons, Ronald J.
Emerging 21st century military missions task engines to deliver the fuel efficiency of a high bypass turbofan while retaining the ability to produce the high specific thrust of a low bypass turbofan. This study explores the possibility of satisfying such competing demands by adding a second independently modulated bypass stream to the basic turbofan architecture. This third stream can be used for a variety of purposes including: providing a cool heat sink for dissipating aircraft heat loads, cooling turbine cooling air, and providing a readily available stream of constant pressure ratio air for lift augmentation. Furthermore, by modulating airflow to the second and third streams, it is possible to continuously match the engine's airflow demand to the inlet's airflow supply thereby reducing spillage and increasing propulsive efficiency. This research begins with a historical perspective of variable cycle engines and shows a logical progression to proposed architectures. Then a novel method for investigating optimal performance is presented which determines most favorable on design variable geometry settings, most beneficial moment to terminate flow holding, and an optimal scheduling of variable features for fuel efficient off design operation. Mission analysis conducted across the three candidate missions verifies that these three stream variable cycles can deliver fuel savings in excess of 30% relative to a year 2000 reference turbofan. This research concludes by evaluating the relative impact of each variable technology on the performance of adaptive engine architectures. The most promising technologies include modulated turbine cooling air, variable high pressure turbine inlet area and variable third stream nozzle throat area. With just these few features it is possible to obtain nearly optimal performance, including 90% or more of the potential fuel savings, with far fewer variable features than are available in the study engine. It is abundantly clear that three stream variable architectures can significantly outperform existing two stream turbofans in both fuel efficiency and at the vehicle system level with only a modest increase in complexity and weight. Such engine architectures should be strongly considered for future military applications.
Method for treating a nuclear process off-gas stream
Pence, Dallas T.; Chou, Chun-Chao
1984-01-01
Disclosed is a method for selectively removing and recovering the noble gas and other gaseous components typically emitted during nuclear process operations. The method is adaptable and useful for treating dissolver off-gas effluents released during reprocessing of spent nuclear fuels whereby to permit radioactive contaminant recovery prior to releasing the remaining off-gases to the atmosphere. Briefly, the method sequentially comprises treating the off-gas stream to preliminarily remove NO.sub.x, hydrogen and carbon-containing organic compounds, and semivolatile fission product metal oxide components therefrom; adsorbing iodine components on silver-exchanged mordenite; removing water vapor carried by said stream by means of a molecular sieve; selectively removing the carbon dioxide components of said off-gas stream by means of a molecular sieve; selectively removing xenon in gas phase by passing said stream through a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from oxygen by means of a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from the bulk nitrogen stream using a molecular sieve comprising silver-exchanged mordenite cooled to about -140.degree. to -160.degree. C.; concentrating the desorbed krypton upon a molecular sieve comprising silver-exchange mordenite cooled to about -140.degree. to -160.degree. C.; and further cryogenically concentrating, and the recovering for storage, the desorbed krypton.
Analysis of the energy efficiency of an integrated ethanol processor for PEM fuel cell systems
NASA Astrophysics Data System (ADS)
Francesconi, Javier A.; Mussati, Miguel C.; Mato, Roberto O.; Aguirre, Pio A.
The aim of this work is to investigate the energy integration and to determine the maximum efficiency of an ethanol processor for hydrogen production and fuel cell operation. Ethanol, which can be produced from renewable feedstocks or agriculture residues, is an attractive option as feed to a fuel processor. The fuel processor investigated is based on steam reforming, followed by high- and low-temperature shift reactors and preferential oxidation, which are coupled to a polymeric fuel cell. Applying simulation techniques and using thermodynamic models the performance of the complete system has been evaluated for a variety of operating conditions and possible reforming reactions pathways. These models involve mass and energy balances, chemical equilibrium and feasible heat transfer conditions (Δ T min). The main operating variables were determined for those conditions. The endothermic nature of the reformer has a significant effect on the overall system efficiency. The highest energy consumption is demanded by the reforming reactor, the evaporator and re-heater operations. To obtain an efficient integration, the heat exchanged between the reformer outgoing streams of higher thermal level (reforming and combustion gases) and the feed stream should be maximized. Another process variable that affects the process efficiency is the water-to-fuel ratio fed to the reformer. Large amounts of water involve large heat exchangers and the associated heat losses. A net electric efficiency around 35% was calculated based on the ethanol HHV. The responsibilities for the remaining 65% are: dissipation as heat in the PEMFC cooling system (38%), energy in the flue gases (10%) and irreversibilities in compression and expansion of gases. In addition, it has been possible to determine the self-sufficient limit conditions, and to analyze the effect on the net efficiency of the input temperatures of the clean-up system reactors, combustion preheating, expander unit and crude ethanol as fuel.
Prediction of the blowout of jet diffusion flames in a coflowing stream of air
DOE Office of Scientific and Technical Information (OSTI.GOV)
Karbasi, M.; Wierzba, I.
1995-12-31
The blowout limits of a lifted diffusion flame in a coflowing stream of air are estimated using a simple model for extinction, for a range of fuels, jet diameters and co-flowing stream velocities. The proposed model uses a parameter which relates to the ratio of a time associated with the mixing processes in a turbulent jet to a characteristic chemical time. The Kolmogorov microscale of time is used as time scale in this model. It is shown that turbulent diffusion flames are quenched by excessive turbulence for a critical value of this parameter. The predicted blowout velocity of diffusion flamesmore » obtained using this model is in good agreement with the available experimental data.« less
Indirect-fired gas turbine dual fuel cell power cycle
Micheli, Paul L.; Williams, Mark C.; Sudhoff, Frederick A.
1996-01-01
A fuel cell and gas turbine combined cycle system which includes dual fuel cell cycles combined with a gas turbine cycle wherein a solid oxide fuel cell cycle operated at a pressure of between 6 to 15 atms tops the turbine cycle and is used to produce CO.sub.2 for a molten carbonate fuel cell cycle which bottoms the turbine and is operated at essentially atmospheric pressure. A high pressure combustor is used to combust the excess fuel from the topping fuel cell cycle to further heat the pressurized gas driving the turbine. A low pressure combustor is used to combust the excess fuel from the bottoming fuel cell to reheat the gas stream passing out of the turbine which is used to preheat the pressurized air stream entering the topping fuel cell before passing into the bottoming fuel cell cathode. The CO.sub.2 generated in the solid oxide fuel cell cycle cascades through the system to the molten carbonate fuel cell cycle cathode.
Wildfire Effects on In-stream Nutrient Processing and Hydrologic Transport
NASA Astrophysics Data System (ADS)
Rhea, A.; Covino, T. P.; Rhoades, C.; Fegel, T.
2017-12-01
In many forests throughout the Western U.S., drought, climate change, and growing fuel loads are contributing to increased fire frequency and severity. Wildfires can influence watershed nutrient retention as they fundamentally alter the biological composition and physical structure in upland landscapes, riparian corridors, and stream channels. While numerous studies have documented substantial short-term increases in stream nutrient concentrations and export (particularly reactive nitrogen, N) following forest fires, the long-term implications for watershed nutrient cycling remain unclear. For example, recent work indicates that nitrate concentrations and export can remain elevated for a decade or more following wildfire, yet the controls on these processes are unknown. In this research, we use empirical observations from nutrient tracer injections, nutrient diffusing substrates, and continuous water quality monitoring to isolate biological and physical controls on nutrient export across a burn-severity gradient. Tracer results demonstrate substantial stream-groundwater exchange, but little biological nutrient uptake in burned streams. This in part explains patterns of elevated nutrient export. Paired nutrient diffusing substrate experiments allow us to further investigate shifts in N, phosphorus, and carbon limitation that may suppress post-fire stream nutrient uptake. By isolating the mechanisms that reduce the capacity of fire-affected streams to retain and transform nutrient inputs, we can better predict dynamics in post-fire water quality and help prioritize upland and riparian restoration.
System Regulates the Water Contents of Fuel-Cell Streams
NASA Technical Reports Server (NTRS)
Vasquez, Arturo; Lazaroff, Scott
2005-01-01
An assembly of devices provides for both humidification of the reactant gas streams of a fuel cell and removal of the product water (the water generated by operation of the fuel cell). The assembly includes externally-sensing forward-pressure regulators that supply reactant gases (fuel and oxygen) at variable pressures to ejector reactant pumps. The ejector supply pressures depend on the consumption flows. The ejectors develop differential pressures approximately proportional to the consumption flow rates at constant system pressure and with constant flow restriction between the mixer-outlet and suction ports of the ejectors. For removal of product water from the circulating oxygen stream, the assembly includes a water/gas separator that contains hydrophobic and hydrophilic membranes. The water separator imposes an approximately constant flow restriction, regardless of the quality of the two-phase flow that enters it from the fuel cell. The gas leaving the water separator is nearly 100 percent humid. This gas is returned to the inlet of the fuel cell along with a quantity of dry incoming oxygen, via the oxygen ejector, thereby providing some humidification.
Coal derived fuel gases for molten carbonate fuel cells
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1979-11-01
Product streams from state-of-the-art and future coal gasification systems are characterized to guide fuel cell program planners and researchers in establishing performance goals and developing materials for molten carbonate fuel cells that will be compatible with gasifier product gases. Results are presented on: (1) the range of gasifier raw-gas compositions available from the major classes of coal gasifiers; (2) the degree of gas clean-up achievable with state-of-the-art and future gas clean-up systems; and (3) the energy penalties associated with gas clean-up. The study encompasses fixed-bed, fluid-bed, entrained-bed, and molten salt gasifiers operating with Eastern bituminous and Western subbituminous coals. Gasifiersmore » operating with air and oxygen blowing are evaluated, and the coal gasification product streams are characterized with respect to: (1) major gas stream constituents, e.g., CO, H/sub 2/, CO/sub 2/, CH/sub 4/, N/sub 2/, H/sub 2/O; (2) major gas stream contaminants, e.g., H/sub 2/S, COS, particulates, tars, etc.; and (3) trace element contaminants, e.g., Na, K, V, Cl, Hg, etc.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sublette, K.L.
With the continual increase in the utilization of high sulfur and high nitrogen containing fossil fuels, the release of airborne pollutants into the environment has become a critical problem. The fuel sulfur is converted to SO{sub 2} during combustion. Fuel nitrogen and a fraction of the nitrogen from the combustion air are converted to nitric oxide and nitrogen dioxide, NO{sub x}. For the past five years Combustion Engineering (now Asea Brown Boveri or ABB) and, since 1986, the University of Tulsa (TU) have been investigating the oxidation of H{sub 2}S by the facultatively anaerobic and autotrophic bacterium Thiobacillus denitrificans andmore » have developed a process, concept for the microbial removal of H{sub 2}S from a gas stream the simultaneous removal of SO{sub 2} and NO by D. desulfuricans and T. denitrificans co-cultures and cultures-in-series was demonstrated. These systems could not be sustained due to NO inhibition of D. desulfuricans. However, a preliminary economic analysis has shown that microbial reduction of SO{sub 2} to H{sub 2}S with subsequent conversion to elemental sulfur by the Claus process is both technically and economically feasible if a less expensive carbon and/or energy source can be found. It has also been demonstrated that T. denitrificans can be grown anaerobically on NO(g) as a terminal electron acceptor with reduction to elemental nitrogen. Microbial reduction of NO{sub x} is a viable process concept for the disposal of concentrated streams of NO{sub x} as may be produced by certain regenerable processes for the removal of SO{sub 2} and NO{sub x} from flue gas.« less
NASA Astrophysics Data System (ADS)
López-Rico, C. A.; Galindo-de-la-Rosa, J.; Ledesma-García, J.; Arriaga, L. G.; Guerra-Balcázar, M.; Arjona, N.
2015-12-01
In this work, a nanofluidic fuel cell (NFC) in which streams flow through electrodes was used to investigate the role of pH in the cell performance using ethanol as fuel and two Pd nanoparticles as electrocatalysts: one commercially available (Pd/C from ETEK) and other synthesized using ionic liquids (Pd/C IL). The cell performances for both electrocatalysts in acid/acid (anodic/cathodic) streams were of 18.05 and 9.55 mW cm-2 for Pd/C ETEK and Pd/C IL. In alkaline/alkaline streams, decrease to 15.94 mW cm-2 for Pd/C ETEK and increase to 15.37 mW cm-2 for Pd/C IL. In alkaline/acidic streams both electrocatalysts showed similar cell voltages (up to 1 V); meanwhile power densities were of 87.6 and 99.4 mW cm-2 for Pd/C ETEK and Pd/C IL. The raise in cell performance can be related to a decrease in activation losses, the combined used of alkaline and acidic streams and these high values compared with flow-over fuel cells can be related to the enhancement of the cathodic mass transport by using three dimensional porous electrodes and two sources of oxygen: from air and from a saturated solution.
Sivy, J.L.; Rodgers, L.W.; Koslosy, J.V.; LaRue, A.D.; Kaufman, K.C.; Sarv, H.
1998-11-03
A burner is described having lower emissions and lower unburned fuel losses by implementing a transition zone in a low NO{sub x} burner. The improved burner includes a pulverized fuel transport nozzle surrounded by the transition zone which shields the central oxygen-lean fuel devolatilization zone from the swirling secondary combustion air. The transition zone acts as a buffer between the primary and the secondary air streams to improve the control of near-burner mixing and flame stability by providing limited recirculation regions between primary and secondary air streams. These limited recirculation regions transport evolved NO{sub x} back towards the oxygen-lean fuel pyrolysis zone for reduction to molecular nitrogen. Alternate embodiments include natural gas and fuel oil firing. 8 figs.
Sivy, Jennifer L.; Rodgers, Larry W.; Koslosy, John V.; LaRue, Albert D.; Kaufman, Keith C.; Sarv, Hamid
1998-01-01
A burner having lower emissions and lower unburned fuel losses by implementing a transition zone in a low NO.sub.x burner. The improved burner includes a pulverized fuel transport nozzle surrounded by the transition zone which shields the central oxygen-lean fuel devolatilization zone from the swirling secondary combustion air. The transition zone acts as a buffer between the primary and the secondary air streams to improve the control of near-burner mixing and flame stability by providing limited recirculation regions between primary and secondary air streams. These limited recirculation regions transport evolved NO.sub.x back towards the oxygen-lean fuel pyrolysis zone for reduction to molecular nitrogen. Alternate embodiments include natural gas and fuel oil firing.
Ranieri, Ezio; Ionescu, Gabriela; Fedele, Arcangela; Palmieri, Eleonora; Ranieri, Ada Cristina; Campanaro, Vincenzo
2017-08-01
This article presents the classification of solid recovered fuel from the Massafra municipal solid waste treatment plant in Southern Italy in compliancy with the EN 15359 standard. In order to ensure the reproducibility of this study, the characterisation methods of waste input and output flow, the mechanical biological treatment line scheme and its main parameters for each stage of the processing chain are presented in details, together with the research results in terms of mass balance and derived fuel properties. Under this study, only 31% of refused municipal solid waste input stream from mechanical biological line was recovered as solid recovered fuel with a net heating value (NC=HV) average of 15.77 MJ kg -1 ; chlorine content average of 0.06% on a dry basis; median of mercury <0.0064 mg MJ -1 and 80th percentile <0.0068 mg MJ -1 . The solid recovered fuel produced meets the European Union standard requirements and can be classified with the class code: Net heating value (3); chlorine (1); mercury (1).
Gasoline toxicology: overview of regulatory and product stewardship programs.
Swick, Derek; Jaques, Andrew; Walker, J C; Estreicher, Herb
2014-11-01
Significant efforts have been made to characterize the toxicological properties of gasoline. There have been both mandatory and voluntary toxicology testing programs to generate hazard characterization data for gasoline, the refinery process streams used to blend gasoline, and individual chemical constituents found in gasoline. The Clean Air Act (CAA) (Clean Air Act, 2012: § 7401, et seq.) is the primary tool for the U.S. Environmental Protection Agency (EPA) to regulate gasoline and this supplement presents the results of the Section 211(b) Alternative Tier 2 studies required for CAA Fuel and Fuel Additive registration. Gasoline blending streams have also been evaluated by EPA under the voluntary High Production Volume (HPV) Challenge Program through which the petroleum industry provide data on over 80 refinery streams used in gasoline. Product stewardship efforts by companies and associations such as the American Petroleum Institute (API), Conservation of Clean Air and Water Europe (CONCAWE), and the Petroleum Product Stewardship Council (PPSC) have contributed a significant amount of hazard characterization data on gasoline and related substances. The hazard of gasoline and anticipated exposure to gasoline vapor has been well characterized for risk assessment purposes. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.
USDA-ARS?s Scientific Manuscript database
The fate of lignin from wheat straw, Miscanthus, and Loblolly pine after pretreatment by a non-toxic and recyclable ionic liquid (IL), [C2mim][OAc], followed by enzymatic hydrolysis was investigated. The lignin partitioned into six process streams, each of which was quantified and analyzed by a comb...
40 CFR 65.165 - Initial Compliance Status Reports.
Code of Federal Regulations, 2010 CFR
2010-07-01
... comply with § 65.144 by routing emissions from a storage vessel or transfer rack to a process or to a... stream is connected to a fuel gas system. (3) As specified in § 65.144(c), report that the transfer rack... storage vessel or low-throughput transfer rack to a nonflare control device or halogen reduction device...
Injection, Atomization, Ignition and Combustion of Liquid Fuels in High-Speed Air Streams.
1983-01-01
evaporiza- tieo. There is, therefore, some tim history of temperature (and vapor pressure) els0 the plum, and that is the process that we wish to simulate...and ~~’m~po 317.6 %Ui es*l11uhes fte e*oints in the heating process for the hot flow case ad te beatl for fte flow p"Islm -to be model led. The task now
Efficiency of a hybrid-type plasma-assisted fuel reformation system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Matveev, I.B.; Serbin, S.I.; Lux, S.M.
2008-12-15
The major advantages of a new plasma-assisted fuel reformation system are its cost effectiveness and technical efficiency. Applied Plasma Technologies has proposed its new highly efficient hybrid-type plasma-assisted system for organic fuel combustion and gasification. The system operates as a multimode multipurpose reactor in a wide range of plasma feedstock gases and turndown ratios. This system also has convenient and simultaneous feeding of several reagents in the reaction zone such as liquid fuels, coal, steam, and air. A special methodology has been developed for such a system in terms of heat balance evaluation and optimization. This methodology considers all existingmore » and possible energy streams, which could influence the system's efficiency. The developed hybrid-type plasma system could be suitable for combustion applications, mobile and autonomous small- to mid-size liquid fuel and coal gasification modules, hydrogen-rich gas generators, waste-processing facilities, and plasma chemical reactors.« less
Seasonal and event-scale controls on dissolved organic carbon and nitrate flushing from catchments
NASA Astrophysics Data System (ADS)
Sebestyen, S. D.; Boyer, E. W.; Shanley, J. B.; Doctor, D. H.
2005-05-01
To explore terrestrial and aquatic linkages controlling nutrient dynamics in forested catchments, we collected high-frequency samples from 2002 to 2004 at the Sleepers River Research Watershed in northeastern Vermont USA. We measured DOC (dissolved organic carbon), SUVA (specific UV absorbance), nitrate, and major ion concentrations over a wide range of flow conditions. In addition, weekly samples since 1991 provide a longer term record of stream nutrient fluxes. During events, DOC concentrations increased with flow consistent with the flushing of a large reservoir of mobile organic carbon from forest soils. Higher concentrations of DOC and SUVA in the growing versus dormant season illustrated seasonal variation in sources, characteristics (i.e. reactivity), availability, and controls on the flushing response of organic matter from the landscape to streams. In contrast, stream nitrate concentrations increased with flow but only when catchments "wetted-up" after baseflow periods. Growing season stream nitrate responses were dependent on short-term antecedent moisture conditions indicating rapid depletion of the soil nitrate reservoir when source areas became hydrologically connected to streams. While the different response patterns emphasized variable source and biogeochemical controls in relation to flow patterns, coupled carbon and nitrogen biogeochemical processes were also important controls on stream nutrient fluxes. In particular, leaf fall was a critical time when reactive DOC from freshly decomposing litter fueled in-stream consumption of nitrate leading to sharp declines of stream nitrate concentrations. Our measurements highlight the importance of "hot spots" and "hot moments" of biogeochemical and hydrological processes that control stream responses. Furthermore, our work illustrates how carbon, nitrogen, and water cycles are coupled in catchments, and provides a conceptual model for future work aimed at modeling forest stream hydrochemistry at the catchment scale.
Refinery Integration of By-Products from Coal-Derived Jet Fuels
DOE Office of Scientific and Technical Information (OSTI.GOV)
Caroline Clifford; Andre Boehman; Chunshan Song
2008-03-31
The final report summarizes the accomplishments toward project goals during length of the project. The goal of this project was to integrate coal into a refinery in order to produce coal-based jet fuel, with the major goal to examine the products other than jet fuel. These products are in the gasoline, diesel and fuel oil range and result from coal-based jet fuel production from an Air Force funded program. The main goal of Task 1 was the production of coal-based jet fuel and other products that would need to be utilized in other fuels or for non-fuel sources, using knownmore » refining technology. The gasoline, diesel fuel, and fuel oil were tested in other aspects of the project. Light cycle oil (LCO) and refined chemical oil (RCO) were blended, hydrotreated to removed sulfur, and hydrogenated, then fractionated in the original production of jet fuel. Two main approaches, taken during the project period, varied where the fractionation took place, in order to preserve the life of catalysts used, which includes (1) fractionation of the hydrotreated blend to remove sulfur and nitrogen, followed by a hydrogenation step of the lighter fraction, and (2) fractionation of the LCO and RCO before any hydrotreatment. Task 2 involved assessment of the impact of refinery integration of JP-900 production on gasoline and diesel fuel. Fuel properties, ignition characteristics and engine combustion of model fuels and fuel samples from pilot-scale production runs were characterized. The model fuels used to represent the coal-based fuel streams were blended into full-boiling range fuels to simulate the mixing of fuel streams within the refinery to create potential 'finished' fuels. The representative compounds of the coal-based gasoline were cyclohexane and methyl cyclohexane, and for the coal-base diesel fuel they were fluorine and phenanthrene. Both the octane number (ON) of the coal-based gasoline and the cetane number (CN) of the coal-based diesel were low, relative to commercial fuels ({approx}60 ON for coal-based gasoline and {approx}20 CN for coal-based diesel fuel). Therefore, the allowable range of blending levels was studied where the blend would achieve acceptable performance. However, in both cases of the coal-based fuels, their ignition characteristics may make them ideal fuels for advanced combustion strategies where lower ON and CN are desirable. Task 3 was designed to develop new approaches for producing ultra clean fuels and value-added chemicals from refinery streams involving coal as a part of the feedstock. It consisted of the following three parts: (1) desulfurization and denitrogenation which involves both new adsorption approach for selective removal of nitrogen and sulfur and new catalysts for more effective hydrotreating and the combination of adsorption denitrogenation with hydrodesulfurization; (2) saturation of two-ring aromatics that included new design of sulfur resistant noble-metal catalysts for hydrogenation of naphthalene and tetralin in middle distillate fuels, and (3) value-added chemicals from naphthalene and biphenyl, which aimed at developing value-added organic chemicals from refinery streams such as 2,6-dimethylnaphthalene and 4,4{prime}-dimethylbiphenyl as precursors to advanced polymer materials. Major advances were achieved in this project in designing the catalysts and sorbent materials, and in developing fundamental understanding. The objective of Task 4 was to evaluate the effect of introducing coal into an existing petroleum refinery on the fuel oil product, specifically trace element emissions. Activities performed to accomplish this objective included analyzing two petroleum-based commercial heavy fuel oils (i.e., No. 6 fuel oils) as baseline fuels and three co-processed fuel oils, characterizing the atomization performance of a No. 6 fuel oil, measuring the combustion performance and emissions of the five fuels, specifically major, minor, and trace elements when fired in a watertube boiler designed for natural gas/fuel oil, and determining the boiler performance when firing the five fuels. Two different co-processed fuel oils were tested: one that had been partially hydrotreated, and the other a product of fractionation before hydrotreating. Task 5 focused on examining refining methods that would utilize coal and produce thermally stable jet fuel, included delayed coking and solvent extraction. Delayed coking was done on blends of decant oil and coal, with the goal to produce a premium carbon product and liquid fuels. Coking was done on bench scale and large laboratory scale cokers. Two coals were examined for co-coking, using Pittsburgh seam coal and Marfork coal product. Reactions in the large, laboratory scaled coker were reproducible in yields of products and in quality of products. While the co-coke produced from both coals was of sponge coke quality, minerals left in the coke made it unacceptable for use as anode or graphite grade filler.« less
A microfluidic direct formate fuel cell on paper.
Copenhaver, Thomas S; Purohit, Krutarth H; Domalaon, Kryls; Pham, Linda; Burgess, Brianna J; Manorothkul, Natalie; Galvan, Vicente; Sotez, Samantha; Gomez, Frank A; Haan, John L
2015-08-01
We describe the first direct formate fuel cell on a paper microfluidic platform. In traditional membrane-less microfluidic fuel cells (MFCs), external pumping consumes power produced by the fuel cell in order to maintain co-laminar flow of the anode stream and oxidant stream to prevent mixing. However, in paper microfluidics, capillary action drives flow while minimizing stream mixing. In this work, we demonstrate a paper MFC that uses formate and hydrogen peroxide as the anode fuel and cathode oxidant, respectively. Using these materials we achieve a maximum power density of nearly 2.5 mW/mg Pd. In a series configuration, our MFC achieves an open circuit voltage just over 1 V, and in a parallel configuration, short circuit of 20 mA absolute current. We also demonstrate that the MFC does not require continuous flow of fuel and oxidant to produce power. We found that we can pre-saturate the materials on the paper, stop the electrolyte flow, and still produce approximately 0.5 V for 15 min. This type of paper MFC has potential applications in point-of-care diagnostic devices and other electrochemical sensors. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
DOE Office of Scientific and Technical Information (OSTI.GOV)
R. T. Jubin; D. M. Strachan; N. R. Soelberg
2013-09-01
Used nuclear fuel is currently being reprocessed in only a few countries, notably France, England, Japan, and Russia. The need to control emissions of the gaseous radionuclides to the air during nuclear fuel reprocessing has already been reported for the entire plant. But since the gaseous radionuclides can partition to various different reprocessing off-gas streams, for example, from the head end, dissolver, vessel, cell, and melter, an understanding of each of these streams is critical. These off-gas streams have different flow rates and compositions and could have different gaseous radionuclide control requirements, depending on how the gaseous radionuclides partition. Thismore » report reviews the available literature to summarize specific engineering data on the flow rates, forms of the volatile radionuclides in off-gas streams, distributions of these radionuclides in these streams, and temperatures of these streams. This document contains an extensive bibliography of the information contained in the open literature.« less
The Advantages of Non-Flow-Through Fuel Cell Power Systems for Aerospace Applications
NASA Technical Reports Server (NTRS)
Hoberecht, Mark; Burke, Kenneth; Jakupca, Ian
2011-01-01
NASA has been developing proton-exchange-membrane (PEM) fuel cell power systems for the past decade, as an upgraded technology to the alkaline fuel cells which presently provide power for the Shuttle Orbiter. All fuel cell power systems consist of one or more fuel cell stacks in combination with appropriate balance-of-plant hardware. Traditional PEM fuel cells are characterized as flow-through, in which recirculating reactant streams remove product water from the fuel cell stack. NASA recently embarked on the development of non-flow-through fuel cell systems, in which reactants are dead-ended into the fuel cell stack and product water is removed by internal wicks. This simplifies the fuel cell power system by eliminating the need for pumps to provide reactant circulation, and mechanical water separators to remove the product water from the recirculating reactant streams. By eliminating these mechanical components, the resulting fuel cell power system has lower mass, volume, and parasitic power requirements, along with higher reliability and longer life. These improved non-flow-through fuel cell power systems therefore offer significant advantages for many aerospace applications.
Oxygen transport membrane based advanced power cycle with low pressure synthesis gas slip stream
Kromer, Brian R.; Litwin, Michael M.; Kelly, Sean M.
2016-09-27
A method and system for generating electrical power in which a high pressure synthesis gas stream generated in a gasifier is partially oxidized in an oxygen transport membrane based reactor, expanded and thereafter, is combusted in an oxygen transport membrane based boiler. A low pressure synthesis gas slip stream is split off downstream of the expanders and used as the source of fuel in the oxygen transport membrane based partial oxidation reactors to allow the oxygen transport membrane to operate at low fuel pressures with high fuel utilization. The combustion within the boiler generates heat to raise steam to in turn generate electricity by a generator coupled to a steam turbine. The resultant flue gas can be purified to produce a carbon dioxide product.
Chemical Technology Division, Annual technical report, 1991
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1992-03-01
Highlights of the Chemical Technology (CMT) Division's activities during 1991 are presented. In this period, CMT conducted research and development in the following areas: (1) electrochemical technology, including advanced batteries and fuel cells; (2) technology for fluidized-bed combustion and coal-fired magnetohydrodynamics; (3) methods for treatment of hazardous and mixed hazardous/radioactive waste; (4) the reaction of nuclear waste glass and spent fuel under conditions expected for an unsaturated repository; (5) processes for separating and recovering transuranic elements from nuclear waste streams; (6) recovery processes for discharged fuel and the uranium blanket in the Integral Fast Reactor (IFR); (7) processes for removalmore » of actinides in spent fuel from commercial water-cooled nuclear reactors and burnup in IFRs; and (8) physical chemistry of selected materials in environments simulating those of fission and fusion energy systems. The Division also conducts basic research in catalytic chemistry associated with molecular energy resources; chemistry of superconducting oxides and other materials of interest with technological application; interfacial processes of importance to corrosion science, catalysis, and high-temperature superconductivity; and the geochemical processes involved in water-rock interactions occurring in active hydrothermal systems. In addition, the Analytical Chemistry Laboratory in CMT provides a broad range of analytical chemistry support services to the technical programs at Argonne National Laboratory (ANL).« less
Chemical Technology Division, Annual technical report, 1991
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1992-03-01
Highlights of the Chemical Technology (CMT) Division`s activities during 1991 are presented. In this period, CMT conducted research and development in the following areas: (1) electrochemical technology, including advanced batteries and fuel cells; (2) technology for fluidized-bed combustion and coal-fired magnetohydrodynamics; (3) methods for treatment of hazardous and mixed hazardous/radioactive waste; (4) the reaction of nuclear waste glass and spent fuel under conditions expected for an unsaturated repository; (5) processes for separating and recovering transuranic elements from nuclear waste streams; (6) recovery processes for discharged fuel and the uranium blanket in the Integral Fast Reactor (IFR); (7) processes for removalmore » of actinides in spent fuel from commercial water-cooled nuclear reactors and burnup in IFRs; and (8) physical chemistry of selected materials in environments simulating those of fission and fusion energy systems. The Division also conducts basic research in catalytic chemistry associated with molecular energy resources; chemistry of superconducting oxides and other materials of interest with technological application; interfacial processes of importance to corrosion science, catalysis, and high-temperature superconductivity; and the geochemical processes involved in water-rock interactions occurring in active hydrothermal systems. In addition, the Analytical Chemistry Laboratory in CMT provides a broad range of analytical chemistry support services to the technical programs at Argonne National Laboratory (ANL).« less
Gug, JeongIn; Cacciola, David; Sobkowicz, Margaret J
2015-01-01
Diversion of waste streams such as plastics, woods, papers and other solid trash from municipal landfills and extraction of useful materials from landfills is an area of increasing interest especially in densely populated areas. One promising technology for recycling municipal solid waste (MSW) is to burn the high-energy-content components in standard coal power plant. This research aims to reform wastes into briquettes that are compatible with typical coal combustion processes. In order to comply with the standards of coal-fired power plants, the feedstock must be mechanically robust, free of hazardous contaminants, and moisture resistant, while retaining high fuel value. This study aims to investigate the effects of processing conditions and added recyclable plastics on the properties of MSW solid fuels. A well-sorted waste stream high in paper and fiber content was combined with controlled levels of recyclable plastics PE, PP, PET and PS and formed into briquettes using a compression molding technique. The effect of added plastics and moisture content on binding attraction and energy efficiency were investigated. The stability of the briquettes to moisture exposure, the fuel composition by proximate analysis, briquette mechanical strength, and burning efficiency were evaluated. It was found that high processing temperature ensures better properties of the product addition of milled mixed plastic waste leads to better encapsulation as well as to greater calorific value. Also some moisture removal (but not complete) improves the compacting process and results in higher heating value. Analysis of the post-processing water uptake and compressive strength showed a correlation between density and stability to both mechanical stress and humid environment. Proximate analysis indicated heating values comparable to coal. The results showed that mechanical and moisture uptake stability were improved when the moisture and air contents were optimized. Moreover, the briquette sample composition was similar to biomass fuels but had significant advantages due to addition of waste plastics that have high energy content compared to other waste types. Addition of PP and HDPE presented better benefits than addition of PET due to lower softening temperature and lower oxygen content. It should be noted that while harmful emissions such as dioxins, furans and mercury can result from burning plastics, WTE facilities have been able to control these emissions to meet US EPA standards. This research provides a drop-in coal replacement that reduces demand on landfill space and replaces a significant fraction of fossil-derived fuel with a renewable alternative. Copyright © 2014 Elsevier Ltd. All rights reserved.
Evaluation of Tritium Content and Release from Pressurized Water Reactor Fuel Cladding
DOE Office of Scientific and Technical Information (OSTI.GOV)
Robinson, Sharon M.; Chattin, Marc Rhea; Giaquinto, Joseph
2015-09-01
It is expected that tritium pretreatment will be required in future reprocessing plants to prevent the release of tritium to the environment (except for long-cooled fuels). To design and operate future reprocessing plants in a safe and environmentally compliant manner, the amount and form of tritium in the used nuclear fuel (UNF) must be understood and quantified. Tritium in light water reactor (LWR) fuel is dispersed between the fuel matrix and the fuel cladding, and some tritium may be in the plenum, probably as tritium labelled water (THO) or T 2O. In a standard processing flowsheet, tritium management would bemore » accomplished by treatment of liquid streams within the plant. Pretreating the fuel prior to dissolution to release the tritium into a single off-gas stream could simplify tritium management, so the removal of tritium in the liquid streams throughout the plant may not be required. The fraction of tritium remaining in the cladding may be reduced as a result of tritium pretreatment. Since Zircaloy® cladding makes up roughly 25% by mass of UNF in the United States, processes are being considered to reduce the volume of reprocessing waste for Zircaloy® clad fuel by recovering the zirconium from the cladding for reuse. These recycle processes could release the tritium in the cladding. For Zircaloy-clad fuels from light water reactors, the tritium produced from ternary fission and other sources is expected to be divided between the fuel, where it is generated, and the cladding. It has been previously documented that a fraction of the tritium produced in uranium oxide fuel from LWRs can migrate and become trapped in the cladding. Estimates of the percentage of tritium in the cladding typically range from 0–96%. There is relatively limited data on how the tritium content of the cladding varies with burnup and fuel history (temperature, power, etc.) and how pretreatment impacts its release. To gain a better understanding of how tritium in cladding will behave during processing, scoping tests are being performed to determine the tritium content in the cladding pre- and post-tritium pretreatment. Samples of Surry-2 and H.B. Robinson pressurized water reactor cladding were heated to 1100–1200°C to oxidize the zirconium and release all of the tritium in the cladding sample. Cladding samples were also heated within the temperature range of 480–600ºC expected for standard air tritium pretreatment systems, and to a slightly higher temperature (700ºC) to determine the impact of tritium pretreatment on tritium release from the cladding. The tritium content of the Surry-2 and H.B. Robinson cladding was measured to be ~234 and ~500 µCi/g, respectively. Heating the Surry-2 cladding at 500°C for 24 h removed ~0.2% of the tritium from the cladding, and heating at 700°C for 24 h removed ~9%. Heating the H.B. Robinson cladding at 700°C for 24 h removed ~11% of the tritium. When samples of the Surry-2 and H.B. Robinson claddings were heated at 700°C for 96 h, essentially all of the tritium in the cladding was removed. However, only ~3% of the tritium was removed when a sample of Surry-2 cladding was heated at 600°C for 96 h. These data indicate that the amount of tritium released from tritium pretreatment systems will be dependent on both the operating temperature and length of time in the system. Under certain conditions, a significant fraction of the tritium could remain bound in the cladding and would need to be considered in operations involving cladding recycle.« less
Fuel-Flexible Gasification-Combustion Technology for Production of H2 and Sequestration-Ready CO2
DOE Office of Scientific and Technical Information (OSTI.GOV)
Parag Kulkarni; Jie Guan; Raul Subia
In the near future, the nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It is necessary to improve both the process efficiency and environmental impact of fossil fuel utilization including greenhouse gas management. GE Global Research (GEGR) investigated an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology with potential to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP technology offers the long-term potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions. GE was awarded a contract from U.S. DOEmore » NETL to investigate and develop the UFP technology. Work started on the Phase I program in October 2000 and on the Phase II effort in April 2005. In the UFP technology, coal, water and air are simultaneously converted into (1) hydrogen rich stream that can be utilized in fuel cells or turbines, (2) CO{sub 2} rich stream for sequestration, and (3) high temperature/pressure vitiated air stream to produce electricity in a gas turbine expander. The process produces near-zero emissions with an estimated efficiency higher than Integrated Gasification Combined Cycle (IGCC) process with conventional CO{sub 2} separation. The Phase I R&D program established the chemical feasibility of the major reactions of the integrated UFP technology through lab-, bench- and pilot-scale testing. A risk analysis session was carried out at the end of Phase I effort to identify the major risks in the UFP technology and a plan was developed to mitigate these risks in the Phase II of the program. The Phase II effort focused on three high-risk areas: economics, lifetime of solids used in the UFP process, and product gas quality for turbines (or the impact of impurities in the coal on the overall system). The economic analysis included estimating the capital cost as well as the costs of hydrogen and electricity for a full-scale UFP plant. These costs were benchmarked with IGCC polygen plants with similar level of CO{sub 2} capture. Based on the promising economic analysis comparison results (performed with the help from Worley Parsons), GE recommended a 'Go' decision in April 2006 to continue the experimental investigation of the UFP technology to address the remaining risks i.e. solids lifetime and the impact of impurities in the coal on overall system. Solids attrition and lifetime risk was addressed via bench-scale experiments that monitor solids performance over time and by assessing materials interactions at operating conditions. The product gas under the third reactor (high-temperature vitiated air) operating conditions was evaluated to assess the concentration of particulates, pollutants and other impurities relative to the specifications required for gas turbine feed streams. During this investigation, agglomeration of solids used in the UFP process was identified as a serious risk that impacts the lifetime of the solids and in turn feasibility of the UFP technology. The main causes of the solids agglomeration were the combination of oxygen transfer material (OTM) reduction at temperatures {approx}1000 C and interaction between OTM and CO{sub 2} absorbing material (CAM) at high operating temperatures (>1200 C). At the end of phase II, in March 2008, GEGR recommended a 'No-go' decision for taking the UFP technology to the next level of development, i.e. development of a 3-5 MW prototype system, at this time. GEGR further recommended focused materials development research programs on improving the performance and lifetime of solids materials used in UFP or chemical looping technologies. The scale-up activities would be recommended only after mitigating the risks involved with the agglomeration and overall lifetime of the solids. This is the final report for the phase II of the DOE-funded Vision 21 program entitled 'Fuel-Flexible Gasification-Combustion Technology for Production of H{sub 2} and Sequestration-Ready CO{sub 2}' (DOE Award No. DE-FC26-00NT40974). The report focuses on the major accomplishments and lessons learned in analyzing the risks of the novel UFP technology during Phase II of the DOE program.« less
Thermal Stability of Acetohydroxamic Acid/Nitric Acid Solutions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rudisill, T.S.
2002-03-13
The transmutation of transuranic actinides and long-lived fission products in spent commercial nuclear reactor fuel has been proposed as one element of the Advanced Accelerator Applications Program. Preparation of targets for irradiation in an accelerator-driven subcritical reactor would involve dissolution of the fuel and separation of uranium, technetium, and iodine from the transuranic actinides and other fission products. The UREX solvent extraction process is being developed to reject and isolate the transuranic actinides in the acid waste stream by scrubbing with acetohydroxamic acid (AHA). To ensure that a runaway reaction will not occur between nitric acid and AHA, an analoguemore » of hydroxyl amine, thermal stability tests were performed to identify if any processing conditions could lead to a runaway reaction.« less
Fusion yield rate recovery by escaping hot-spot fast ions in the neighboring fuel layer
NASA Astrophysics Data System (ADS)
Tang, Xian-Zhu; McDevitt, C. J.; Guo, Zehua; Berk, H. L.
2014-02-01
Free-streaming loss by fast ions can deplete the tail population in the hot spot of an inertial confinement fusion (ICF) target. Escaping fast ions in the neighboring fuel layer of a cryogenic target can produce a surplus of fast ions locally. In contrast to the Knudsen layer effect that reduces hot-spot fusion reactivity due to tail ion depletion, the inverse Knudsen layer effect increases fusion reactivity in the neighboring fuel layer. In the case of a burning ICF target in the presence of significant hydrodynamic mix which aggravates the Knudsen layer effect, the yield recovery largely compensates for the yield reduction. For mix-dominated sub-ignition targets, the yield reduction is the dominant process.
A study of flame spread in engineered cardboard fuelbeds: Part I: Correlations and observations
Mark A. Finney; Jason Forthofer; Isaac C. Grenfell; Brittany A. Adam; Nelson K. Akafuah; Kozo Saito
2013-01-01
Wind tunnel laboratory fires spreading through laser-cut cardboard fuel beds were instrumented and analyzed for physical processes associated with spread. Flames in the span-wise direction appeared as a regular series of peaks-and-troughs that scaled directly with flame length. Flame structure in the stream-wise direction fluctuated with the forward advection of...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bruffey, Stephanie H.; Spencer, Barry B.; Jubin, Robert Thomas
2013-12-01
The objective of this test plan is to describe research that will determine the effectiveness of silver mordenite and molecular sieve beds to remove iodine and water (tritium) from off-gas streams arising from used nuclear fuel recycling processes, and to demonstrate that the iodine and water can be recovered separately from one another.
40 CFR 63.107 - Identification of process vents subject to this subpart.
Code of Federal Regulations, 2010 CFR
2010-07-01
... to this subpart. 63.107 Section 63.107 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... going to a fuel gas system as defined in § 63.101. (4) A gas stream exiting a control device used to... transfer operation vent subject to § 63.119 or § 63.126. (8) A vent from a waste management unit subject to...
40 CFR 63.997 - Performance test and compliance assessment requirements for control devices.
Code of Federal Regulations, 2011 CFR
2011-07-01
...), each run shall represent at least one complete tank truck or tank car loading period, during which... stream is introduced with the combustion air or as a secondary fuel into a boiler or process heater with... specified in paragraph (e)(2)(iii)(C) of this section if a combustion device is the control device and...
Low NO{sub x} turbine power generation utilizing low Btu GOB gas. Final report, June--August 1995
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ortiz, I.; Anthony, R.V.; Gabrielson, J.
1995-08-01
Methane, a potent greenhouse gas, is second only to carbon dioxide as a contributor to potential global warming. Methane liberated by coal mines represents one of the most promising under exploited areas for profitably reducing these methane emissions. Furthermore, there is a need for apparatus and processes that reduce the nitrogen oxide (NO{sub x}) emissions from gas turbines in power generation. Consequently, this project aims to demonstrate a technology which utilizes low grade fuel (CMM) in a combustion air stream to reduce NO{sub x} emissions in the operation of a gas turbine. This technology is superior to other existing technologiesmore » because it can directly use the varying methane content gases from various streams of the mining operation. The simplicity of the process makes it useful for both new gas turbines and retrofitting existing gas turbines. This report evaluates the feasibility of using gob gas from the 11,000 acre abandoned Gateway Mine near Waynesburg, Pennsylvania as a fuel source for power generation applying low NO{sub x} gas turbine technology at a site which is currently capable of producing low grade GOB gas ({approx_equal} 600 BTU) from abandoned GOB areas.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Elliott, Douglas C.; Olarte, Mariefel V.; Hart, Todd R.
2015-06-19
DOE-EE Bioenergy Technologies Office has set forth several goals to increase the use of bioenergy and bioproducts derived from renewable resources. One of these goals is to facilitate the implementation of the biorefinery. The biorefinery will include the production of liquid fuels, power and, in some cases, products. The integrated biorefinery should stand-alone from an economic perspective with fuels and power driving the economy of scale while the economics/profitability of the facility will be dependent on existing market conditions. UOP LLC proposed to demonstrate a fast pyrolysis based integrated biorefinery. Pacific Northwest National Laboratory (PNNL) has expertise in an importantmore » technology area of interest to UOP for use in their pyrolysis-based biorefinery. This CRADA project provides the supporting technology development and demonstration to allow incorporation of this technology into the biorefinery. PNNL developed catalytic hydrothermal gasification (CHG) for use with aqueous streams within the pyrolysis biorefinery. These aqueous streams included the aqueous phase separated from the fast pyrolysis bio-oil and the aqueous byproduct streams formed in the hydroprocessing of the bio-oil to finished products. The purpose of this project was to demonstrate a technically and economically viable technology for converting renewable biomass feedstocks to sustainable and fungible transportation fuels. To demonstrate the technology, UOP constructed and operated a pilot-scale biorefinery that processed one dry ton per day of biomass using fast pyrolysis. Specific objectives of the project were to: The anticipated outcomes of the project were a validated process technology, a range of validated feedstocks, product property and Life Cycle data, and technical and operating data upon which to base the design of a full-scale biorefinery. The anticipated long-term outcomes from successful commercialization of the technology were: (1) the replacement of a significant fraction of petroleum based fuels with advanced biofuels, leading to increased energy security and decreased carbon footprint; and (2) establishment of a new biofuel industry segment, leading to the creation of U.S. engineering, manufacturing, construction, operations and agricultural jobs. PNNL development of CHG progressed at two levels. Initial tests were made in the laboratory in both mini-scale and bench-scale continuous flow reactor systems. Following positive results, the next level of evaluation was in the scaled-up engineering development system, which was operated at PNNL.« less
Flexible biorefinery for producing fermentation sugars, lignin and pulp from corn stover.
Kadam, Kiran L; Chin, Chim Y; Brown, Lawrence W
2008-05-01
A new biorefining process is presented that embodies green processing and sustainable development. In the spirit of a true biorefinery, the objective is to convert agricultural residues and other biomass feedstocks into value-added products such as fuel ethanol, dissolving pulp, and lignin for resin production. The continuous biomass fractionation process yields a liquid stream rich in hemicellulosic sugars, a lignin-rich liquid stream, and a solid cellulose stream. This paper generally discusses potential applications of the three streams and specifically provides results on the evaluation of the cellulose stream from corn stover as a source of fermentation sugars and specialty pulp. Enzymatic hydrolysis of this relatively pure cellulose stream requires significantly lower enzyme loadings because of minimal enzyme deactivation from nonspecific binding to lignin. A correlation was shown to exist between lignin removal efficiency and enzymatic digestibility. The cellulose produced was also demonstrated to be a suitable replacement for hardwood pulp, especially in the top ply of a linerboard. Also, the relatively pure nature of the cellulose renders it suitable as raw material for making dissolving pulp. This pulping approach has significantly smaller environmental footprint compared to the industry-standard kraft process because no sulfur- or chlorine-containing compounds are used. Although this option needs some minimal post-processing, it produces a higher value commodity than ethanol and, unlike ethanol, does not need extensive processing such as hydrolysis or fermentation. Potential use of low-molecular weight lignin as a raw material for wood adhesive production is discussed as well as its use as cement and feed binder. As a baseline application the hemicellulosic sugars captured in the hydrolyzate liquor can be used to produce ethanol, but potential utilization of xylose for xylitol fermentation is also feasible. Markets and values of these applications are juxtaposed with market penetration and saturation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mueller, Charles J.; Cannella, William J.; Bruno, Thomas J.
In this study, a novel approach was developed to formulate surrogate fuels having characteristics that are representative of diesel fuels produced from real-world refinery streams. Because diesel fuels typically consist of hundreds of compounds, it is difficult to conclusively determine the effects of fuel composition on combustion properties. Surrogate fuels, being simpler representations of these practical fuels, are of interest because they can provide a better understanding of fundamental fuel-composition and property effects on combustion and emissions-formation processes in internal-combustion engines. In addition, the application of surrogate fuels in numerical simulations with accurate vaporization, mixing, and combustion models could revolutionizemore » future engine designs by enabling computational optimization for evolving real fuels. Dependable computational design would not only improve engine function, it would do so at significant cost savings relative to current optimization strategies that rely on physical testing of hardware prototypes. The approach in this study utilized the stateof- the-art techniques of 13C and 1H nuclear magnetic resonance spectroscopy and the advanced distillation curve to characterize fuel composition and volatility, respectively. The ignition quality was quantified by the derived cetane number. Two wellcharacterized, ultra-low-sulfur #2 diesel reference fuels produced from refinery streams were used as target fuels: a 2007 emissions certification fuel and a Coordinating Research Council (CRC) Fuels for Advanced Combustion Engines (FACE) diesel fuel. A surrogate was created for each target fuel by blending eight pure compounds. The known carbon bond types within the pure compounds, as well as models for the ignition qualities and volatilities of their mixtures, were used in a multiproperty regression algorithm to determine optimal surrogate formulations. The predicted and measured surrogate-fuel properties were quantitatively compared to the measured target-fuel properties, and good agreement was found. This paper is dedicated to the memory of our friend and colleague Jim Franz. Funding for this research was provided by the U.S. Department of Energy (U.S. DOE) Office of Vehicle Technologies, and by the Coordinating Research Council (CRC) and the companies that employ the CRC members. The study was conducted under the auspices of CRC. The authors thank U.S. DOE program manager Kevin Stork for supporting the participation of the U.S. national laboratories in this study.« less
Fuel cell membrane hydration and fluid metering
Jones, Daniel O.; Walsh, Michael M.
2003-01-01
A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).
Electrochemical Upgrading of Bio-Oil
DOE Office of Scientific and Technical Information (OSTI.GOV)
Elangovan, S.; Larsen, Dennis; Bay, Insoo
Bio-oil produced by fast pyrolysis of biomass is a potential source of low carbon, renewable hydrocarbon fuel. However, the properties such as low heating value, incomplete volatility, acidity, instability, and incompatibility with standard fuels restrict its use. The undesirable properties of pyrolysis oil result from its chemical composition that mostly consists of different classes of oxygenated organic compounds. Current process of Hydrodeoxygenation to remove oxygen involves high-temperature, high-pressure processing in the presence of hydrogen and catalyst. An alternative process of deoxygenation of bio-oil using solid-state, oxygen conductor based electrochemical cell is under investigation. The electrolysis process removes oxygen from themore » oxygenated organic molecule as well from steam to produce hydrogen in-situ allowing for a distributed, small scale integrated upgrading unit. Mixtures of model compounds and a slip stream of pyrolysis vapor were tested. The results show the potential for integrating a pyrolyzer and an electrochemical device for stabilizing pyrolysis oil.« less
Fuel Injector With Shear Atomizer
NASA Technical Reports Server (NTRS)
Beal, George W.; Mills, Virgil L.; Smith, Durward B., II; Beacom, William F.
1995-01-01
Atomizer for injecting liquid fuel into combustion chamber uses impact and swirl to break incoming stream of fuel into small, more combustible droplets. Slanted holes direct flow of liquid fuel to stepped cylindrical wall. Impact on wall atomizes liquid. Air flowing past vanes entrains droplets of liquid in swirling flow. Fuel injected at pressure lower than customarily needed.
Grot, Stephen Andreas; Meltser, Mark Alexander; Gutowski, Stanley; Neutzler, Jay Kevin; Borup, Rodney Lynn; Weisbrod, Kirk
1999-12-14
The CO concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and/or voltage behavior patterns from a PEM-probe communicating with the reformate feed stream. Pattern recognition software may be used to compare the current and voltage patterns from the PEM-probe to current and voltage telltale outputs determined from a reference cell similar to the PEM-probe and operated under controlled conditions over a wide range of CO concentrations in the H.sub.2 fuel stream. A CO sensor includes the PEM-probe, an electrical discharge circuit for discharging the PEM-probe to monitor the CO concentration, and an electrical purging circuit to intermittently raise the anode potential of the PEM-probe's anode to at least about 0.8 V (RHE) to electrochemically oxidize any CO adsorbed on the probe's anode catalyst.
Method of monitoring CO concentrations in hydrogen feed to a PEM fuel cell
Grot, Stephen Andreas; Meltser, Mark Alexander; Gutowski, Stanley; Neutzler, Jay Kevin; Borup, Rodney Lynn; Weisbrod, Kirk
2000-01-01
The CO concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and/or voltage behavior patterns from a PEM-probe communicating with the reformate feed stream. Pattern recognition software may be used to compare the current and voltage patterns from the PEM-probe to current and voltage telltale outputs determined from a reference cell similar to the PEM-probe and operated under controlled conditions over a wide range of CO concentrations in the H.sub.2 fuel stream. The PEM-probe is intermittently purged of any CO build-up on the anode catalyst (e.g., by (1) flushing the anode with air, (2) short circuiting the PEM-probe, or (3) reverse biasing the PEM-probe) to keep the PEM-probe at peak performance levels.
Solar heated oil shale pyrolysis process
NASA Technical Reports Server (NTRS)
Qader, S. A. (Inventor)
1985-01-01
An improved system for recovery of a liquid hydrocarbon fuel from oil shale is presented. The oil shale pyrolysis system is composed of a retort reactor for receiving a bed of oil shale particules which are heated to pyrolyis temperature by means of a recycled solar heated gas stream. The gas stream is separated from the recovered shale oil and a portion of the gas stream is rapidly heated to pyrolysis temperature by passing it through an efficient solar heater. Steam, oxygen, air or other oxidizing gases can be injected into the recycle gas before or after the recycle gas is heated to pyrolysis temperature and thus raise the temperature before it enters the retort reactor. The use of solar thermal heat to preheat the recycle gas and optionally the steam before introducing it into the bed of shale, increases the yield of shale oil.
Use of MRF residue as alternative fuel in cement production.
Fyffe, John R; Breckel, Alex C; Townsend, Aaron K; Webber, Michael E
2016-01-01
Single-stream recycling has helped divert millions of metric tons of waste from landfills in the U.S., where recycling rates for municipal solid waste are currently over 30%. However, material recovery facilities (MRFs) that sort the municipal recycled streams do not recover 100% of the incoming material. Consequently, they landfill between 5% and 15% of total processed material as residue. This residue is primarily composed of high-energy-content non-recycled plastics and fiber. One possible end-of-life solution for these energy-dense materials is to process the residue into Solid Recovered Fuel (SRF) that can be used as an alternative energy resource capable of replacing or supplementing fuel resources such as coal, natural gas, petroleum coke, or biomass in many industrial and power production processes. This report addresses the energetic and environmental benefits and trade-offs of converting non-recycled post-consumer plastics and fiber derived from MRF residue streams into SRF for use in a cement kiln. An experimental test burn of 118 Mg of SRF in the precalciner portion of the cement kiln was conducted. The SRF was a blend of 60% MRF residue and 40% post-industrial waste products producing an estimated 60% plastic and 40% fibrous material mixture. The SRF was fed into the kiln at 0.9 Mg/h for 24h and then 1.8 Mg/h for the following 48 h. The emissions data recorded in the experimental test burn were used to perform the life-cycle analysis portion of this study. The analysis included the following steps: transportation, landfill, processing and fuel combustion at the cement kiln. The energy use and emissions at each step is tracked for the two cases: (1) The Reference Case, where MRF residue is disposed of in a landfill and the cement kiln uses coal as its fuel source, and (2) The SRF Case, in which MRF residue is processed into SRF and used to offset some portion of coal use at the cement kiln. The experimental test burn and accompanying analysis indicate that using MRF residue to produce SRF for use in cement kilns is likely an advantageous alternative to disposal of the residue in landfills. The use of SRF can offset fossil fuel use, reduce CO2 emissions, and divert energy-dense materials away from landfills. For this test-case, the use of SRF offset between 7700 and 8700 Mg of coal use, reduced CO2 emissions by at least 1.4%, and diverted over 7950 Mg of energy-dense materials away from landfills. In addition, emissions were reduced by at least 19% for SO2, while NOX emissions increased by between 16% and 24%. Changes in emissions of particulate matter, mercury, hydrogen chloride, and total-hydrocarbons were all less than plus or minus 2.2%, however these emissions were not measured at the cement kiln. Co-location of MRFs, SRF production facilities, and landfills can increase the benefits of SRF use even further by reducing transportation requirements. Copyright © 2015 Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bruffey, Stephanie H.; Jubin, Robert Thomas; Jordan, J. A.
U.S. regulations will require the removal of 129I from the off-gas streams of any used nuclear fuel (UNF) reprocessing plant prior to discharge of the off-gas to the environment. Multiple off-gas streams within a UNF reprocessing plant combine prior to release, and each of these streams contains some amount of iodine. For an aqueous UNF reprocessing plant, these streams include the dissolver off-gas, the cell off-gas, the vessel off-gas (VOG), the waste off-gas and the shear off-gas. To achieve regulatory compliance, treatment of multiple off-gas streams within the plant must be performed. Preliminary studies have been completed on the adsorptionmore » of I 2 onto silver mordenite (AgZ) from prototypical VOG streams. The study reported that AgZ did adsorb I 2 from a prototypical VOG stream, but process upsets resulted in an uneven feed stream concentration. The experiments described in this document both improve the characterization of I 2 adsorption by AgZ from dilute gas streams and further extend it to include characterization of the adsorption of organic iodides (in the form of CH 3I) onto AgZ under prototypical VOG conditions. The design of this extended duration testing was such that information about the rate of adsorption, the penetration of the iodine species, and the effect of sorbent aging on iodine removal in VOG conditions could be inferred.« less
Rini, Michael J.; Towle, David P.
1992-01-01
A pulverized coal fuel injector contains an acceleration section to improve the uniformity of a coal-air mixture to be burned. An integral splitter is provided which divides the coal-air mixture into a number separate streams or jets, and a center body directs the streams at a controlled angle into the primary zone of a burner. The injector provides for flame shaping and the control of NO/NO.sub.2 formation.
Study on atomization features of a plain injector in high speed transverse air stream
NASA Astrophysics Data System (ADS)
Wan, Jian; Gu, Shanjian; Yang, Maolin; Xiao, Weihui
1990-04-01
The atomization features of a plain injector in high-speed transverse air stream were investigated by Malvern. In this investigation, air velocity ranged from 50-150m/s, pressure drop of fuel injector, (1.1 - 4.2) x 10 to the 6th Pa, diameter of orifice, 0.5 - 0.9 mm, axial distance between the injector and the survey plane, 50 - 250 mm. Aviation kerosene was used in all experiments. It was found that the atomization features in high pressure drop of fuel injector were greatly differed from the low pressure drop of fuel injector.
Coal liquefaction with preasphaltene recycle
Weimer, Robert F.; Miller, Robert N.
1986-01-01
A coal liquefaction system is disclosed with a novel preasphaltene recycle from a supercritical extraction unit to the slurry mix tank wherein the recycle stream contains at least 90% preasphaltenes (benzene insoluble, pyridine soluble organics) with other residual materials such as unconverted coal and ash. This subject process results in the production of asphaltene materials which can be subjected to hydrotreating to acquire a substitute for No. 6 fuel oil. The preasphaltene-predominant recycle reduces the hydrogen consumption for a process where asphaltene material is being sought.
DOE Office of Scientific and Technical Information (OSTI.GOV)
O'Neil, D.J.; Colcord, A.R.; Bery, M.K.
The objective of this project is to design, fabricate, and operate a fermentation facility which will demonstrate on a pilot-scale level (3 oven-dry tons (ODT) per day of feedstock) the economic and technical feasibility of producing anhydrous ethyl alcohol from lignocellulosic biomass residues (wood, corn stover, and wheat straw principally). The resultant process development unit (PDU) will be flexibly designed so as to evaluate current and projected unit operations, materials of construction, chemical and enzymatic systems which offer the potential of significant technological and economic breakthroughs in alcohol production from biomass. The principal focus of the project is to generatemore » fuels from biomass. As such, in addition to alcohol which can be used as a transportation fuel, by-products are to be directed where possible to fuel applications. The project consists of two parts: (1) conceptual design, and (2) detailed engineering design. The first quarter's activities have focused on a critical review of several aspects of the conceptual design of the 3 ODT/day PDU, viz.: (1) biomass cost, availability, and characterization; (2) pretreatment processes for lignocellulosic residues; (3) hydrolytic processes (enzymatic and acidic); (4) fermentation processes; (5) alcohol recovery systems; (6) by-product streams utilization; and (7) process economics.« less
Spectroscopic methods of process monitoring for safeguards of used nuclear fuel separations
NASA Astrophysics Data System (ADS)
Warburton, Jamie Lee
To support the demonstration of a more proliferation-resistant nuclear fuel processing plant, techniques and instrumentation to allow the real-time, online determination of special nuclear material concentrations in-process must be developed. An ideal materials accountability technique for proliferation resistance should provide nondestructive, realtime, on-line information of metal and ligand concentrations in separations streams without perturbing the process. UV-Visible spectroscopy can be adapted for this precise purpose in solvent extraction-based separations. The primary goal of this project is to understand fundamental URanium EXtraction (UREX) and Plutonium-URanium EXtraction (PUREX) reprocessing chemistry and corresponding UV-Visible spectroscopy for application in process monitoring for safeguards. By evaluating the impact of process conditions, such as acid concentration, metal concentration and flow rate, on the sensitivity of the UV-Visible detection system, the process-monitoring concept is developed from an advanced application of fundamental spectroscopy. Systematic benchtop-scale studies investigated the system relevant to UREX or PUREX type reprocessing systems, encompassing 0.01-1.26 M U and 0.01-8 M HNO3. A laboratory-scale TRansUranic Extraction (TRUEX) demonstration was performed and used both to analyze for potential online monitoring opportunities in the TRUEX process, and to provide the foundation for building and demonstrating a laboratory-scale UREX demonstration. The secondary goal of the project is to simulate a diversion scenario in UREX and successfully detect changes in metal concentration and solution chemistry in a counter current contactor system with a UV-Visible spectroscopic process monitor. UREX uses the same basic solvent extraction flowsheet as PUREX, but has a lower acid concentration throughout and adds acetohydroxamic acid (AHA) as a complexant/reductant to the feed solution to prevent the extraction of Pu. By examining UV-Visible spectra gathered in real time, the objective is to detect the conversion from the UREX process, which does not separate Pu, to the PUREX process, which yields a purified Pu product. The change in process chemistry can be detected in the feed solution, aqueous product or in the raffinate stream by identifying the acid concentration, metal distribution and the presence or absence of AHA. A fiber optic dip probe for UV-Visible spectroscopy was integrated into a bank of three counter-current centrifugal contactors to demonstrate the online process monitoring concept. Nd, Fe and Zr were added to the uranyl nitrate system to explore spectroscopic interferences and identify additional species as candidates for online monitoring. This milestone is a demonstration of the potential of this technique, which lies in the ability to simultaneously and directly monitor the chemical process conditions in a reprocessing plant, providing inspectors with another tool to detect nuclear material diversion attempts. Lastly, dry processing of used nuclear fuel is often used as a head-end step before solvent extraction-based separations such as UREX or TRUEX. A non-aqueous process, used fuel treatment by dry processing generally includes chopping of used fuel rods followed by repeated oxidation-reduction cycles and physical separation of the used fuel from the cladding. Thus, dry processing techniques are investigated and opportunities for online monitoring are proposed for continuation of this work in future studies.
System for operating solid oxide fuel cell generator on diesel fuel
NASA Technical Reports Server (NTRS)
Singh, Prabhu (Inventor); George, Raymond A. (Inventor)
1997-01-01
A system is provided for operating a solid oxide fuel cell generator on diesel fuel. The system includes a hydrodesulfurizer which reduces the sulfur content of commercial and military grade diesel fuel to an acceptable level. Hydrogen which has been previously separated from the process stream is mixed with diesel fuel at low pressure. The diesel/hydrogen mixture is then pressurized and introduced into the hydrodesulfurizer. The hydrodesulfurizer comprises a metal oxide such as ZnO which reacts with hydrogen sulfide in the presence of a metal catalyst to form a metal sulfide and water. After desulfurization, the diesel fuel is reformed and delivered to a hydrogen separator which removes most of the hydrogen from the reformed fuel prior to introduction into a solid oxide fuel cell generator. The separated hydrogen is then selectively delivered to the diesel/hydrogen mixer or to a hydrogen storage unit. The hydrogen storage unit preferably comprises a metal hydride which stores hydrogen in solid form at low pressure. Hydrogen may be discharged from the metal hydride to the diesel/hydrogen mixture at low pressure upon demand, particularly during start-up and shut-down of the system.
Noppadon Sathitsuksanoh; Kevin M. Holtman; Daniel J. Yelle; Trevor Morgan; Vitalie Stavila; Jeffrey Pelton; Harvey Blanch; Blake A. Simmons; Anthe George
2014-01-01
The fate of lignin from wheat straw, Miscanthus, and Loblolly pine after pretreatment by a non-toxic and recyclable ionic liquid (IL), [C2mim][OAc], followed by enzymatic hydrolysis was investigated. The lignin partitioned into six process streams, each of which was quantified and analyzed by a combination of a novel solution-state two-dimensional (2D) nuclear magnetic...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gug, JeongIn, E-mail: Jeongin_gug@student.uml.edu; Cacciola, David, E-mail: david_cacciola@student.uml.edu; Sobkowicz, Margaret J., E-mail: Margaret_sobkowiczkline@uml.edu
Highlights: • Briquetting was used to produce solid fuels from municipal solid waste and recycled plastics. • Optimal drying, processing temperature and pressure were found to produce stable briquettes. • Addition of waste plastics yielded heating values comparable with typical coal feedstocks. • This processing method improves utilization of paper and plastic diverted from landfills. - Abstract: Diversion of waste streams such as plastics, woods, papers and other solid trash from municipal landfills and extraction of useful materials from landfills is an area of increasing interest especially in densely populated areas. One promising technology for recycling municipal solid waste (MSW)more » is to burn the high-energy-content components in standard coal power plant. This research aims to reform wastes into briquettes that are compatible with typical coal combustion processes. In order to comply with the standards of coal-fired power plants, the feedstock must be mechanically robust, free of hazardous contaminants, and moisture resistant, while retaining high fuel value. This study aims to investigate the effects of processing conditions and added recyclable plastics on the properties of MSW solid fuels. A well-sorted waste stream high in paper and fiber content was combined with controlled levels of recyclable plastics PE, PP, PET and PS and formed into briquettes using a compression molding technique. The effect of added plastics and moisture content on binding attraction and energy efficiency were investigated. The stability of the briquettes to moisture exposure, the fuel composition by proximate analysis, briquette mechanical strength, and burning efficiency were evaluated. It was found that high processing temperature ensures better properties of the product addition of milled mixed plastic waste leads to better encapsulation as well as to greater calorific value. Also some moisture removal (but not complete) improves the compacting process and results in higher heating value. Analysis of the post-processing water uptake and compressive strength showed a correlation between density and stability to both mechanical stress and humid environment. Proximate analysis indicated heating values comparable to coal. The results showed that mechanical and moisture uptake stability were improved when the moisture and air contents were optimized. Moreover, the briquette sample composition was similar to biomass fuels but had significant advantages due to addition of waste plastics that have high energy content compared to other waste types. Addition of PP and HDPE presented better benefits than addition of PET due to lower softening temperature and lower oxygen content. It should be noted that while harmful emissions such as dioxins, furans and mercury can result from burning plastics, WTE facilities have been able to control these emissions to meet US EPA standards. This research provides a drop-in coal replacement that reduces demand on landfill space and replaces a significant fraction of fossil-derived fuel with a renewable alternative.« less
Fuel cell anode configuration for CO tolerance
Uribe, Francisco A.; Zawodzinski, Thomas A.
2004-11-16
A polymer electrolyte fuel cell (PEFC) is designed to operate on a reformate fuel stream containing oxygen and diluted hydrogen fuel with CO impurities. A polymer electrolyte membrane has an electrocatalytic surface formed from an electrocatalyst mixed with the polymer and bonded on an anode side of the membrane. An anode backing is formed of a porous electrically conductive material and has a first surface abutting the electrocatalytic surface and a second surface facing away from the membrane. The second surface has an oxidation catalyst layer effective to catalyze the oxidation of CO by oxygen present in the fuel stream where at least the layer of oxidation catalyst is formed of a non-precious metal oxidation catalyst selected from the group consisting of Cu, Fe, Co, Tb, W, Mo, Sn, and oxides thereof, and other metals having at least two low oxidation states.
Characterization of the Kinetics of NF3-Fluorination of NpO2
DOE Office of Scientific and Technical Information (OSTI.GOV)
Casella, Andrew M.; Scheele, Randall D.; McNamara, Bruce K.
2015-12-23
The exploitation of selected actinide and fission product fluoride volatilities has long been considered as a potentially attractive compact method for recycling used nuclear fuels to avoid generating the large volumes of radioactive waste arising from aqueous reprocessing [1-7]. The most developed process uses the aggressive and hazardous fluorinating agents hydrogen fluoride (HF) and/or molecular fluorine (F2) at high temperatures to volatilize the greatest fraction of the used nuclear fuel into a single gas stream. The volatilized fluorides are subsequently separated using a series of fractionation and condensation columns to recover the valuable fuel constituents and fission products. In pursuitmore » of a safer and less complicated approach, we investigated an alternative fluoride volatility-based process using the less hazardous fluorinating agent nitrogen trifluoride (NF3) and leveraging its less aggressive nature to selectively evolve fission product and actinide fluorides from the solid phase based on their reaction temperatures into a single recycle stream [8-15]. In this approach, successive isothermal treatments using NF3 will first evolve the more thermally susceptible used nuclear fuel constituents leaving the other constituents in the residual solids until subsequent isothermal temperature treatments cause these others to volatilize. During investigation of this process, individual neat used fuel components were treated with isothermal NF3 in an attempt to characterize the kinetics of each fluorination reaction to provide input into the design of a new volatile fluoride separations approach. In these directed investigations, complex behavior was observed between NF3 and certain solid reactants such as the actinide oxides of uranium, plutonium, and neptunium. Given the similar thermal reaction susceptibilities of neptunium oxide (NpO2) and uranium dioxide (UO2) and the importance of Np and U, we initially focused our efforts on determining the reaction kinetic parameters for NpO2. Characterizing the NF3 fluorination of NpO2 using established models for gas-solid reactions [16] proved unsuccessful so we developed a series of successive fundamental reaction mechanisms to characterize the observed successive fluorination reactions leading to production of the volatile neptunium hexafluoride (NpF6).« less
Waste Estimates for a Future Recycling Plant in the US Based Upon AREVA Operating Experience - 13206
DOE Office of Scientific and Technical Information (OSTI.GOV)
Foare, Genevieve; Meze, Florian; Bader, Sven
2013-07-01
Estimates of process and secondary wastes produced by a recycling plant built in the U.S., which is composed of a used nuclear fuel (UNF) reprocessing facility and a mixed oxide (MOX) fuel fabrication facility, are performed as part of a U.S. Department of Energy (DOE) sponsored study [1]. In this study, a set of common inputs, assumptions, and constraints were identified to allow for comparison of these wastes between different industrial teams. AREVA produced a model of a reprocessing facility, an associated fuel fabrication facility, and waste treatment facilities to develop the results for this study. These facilities were dividedmore » into a number of discrete functional areas for which inlet and outlet flow streams were clearly identified to allow for an accurate determination of the radionuclide balance throughout the facility and the waste streams. AREVA relied primarily on its decades of experience and feedback from its La Hague (reprocessing) and MELOX (MOX fuel fabrication) commercial operating facilities in France to support this assessment. However, to perform these estimates for a U.S. facility with different regulatory requirements and to take advantage of some technological advancements, such as in the potential treatment of off-gases, some deviations from this experience were necessary. A summary of AREVA's approach and results for the recycling of 800 metric tonnes of initial heavy metal (MTIHM) of LWR UNF per year into MOX fuel under the assumptions and constraints identified for this DOE study are presented. (authors)« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Spencer, Barry B.; Bruffey, Stephanie H.; Jordan, Jacob A.
US regulations will require the removal of iodine and tritium, along with other volatile and semi-volatile radionuclides, from the off-gas streams of nuclear fuel reprocessing plants. Advanced tritium pretreatment (TPT) is an additional head-end operation that could be incorporated within nuclear fuel reprocessing plants. It utilizes nitrogen dioxide (NOR2R) as an oxidant to convert UOR2R to UR3ROR8R prior to traditional aqueous dissolution. Advanced TPT can result in the quantitative volatilization of both tritium and iodine. Up-front removal of iodine is of significant advantage because otherwise it distributes to several unit operations and the associated off-gas streams. The off-gas streams willmore » then require treatment to comply with US regulations. Advanced TPT is currently under development at Oak Ridge National Laboratory, and a kilogram-scale hot cell demonstration with used nuclear fuel (UNF) is planned for fiscal year (FY) 2018.« less
A new method of thermal protection by opposing jet for a hypersonic aeroheating strut
NASA Astrophysics Data System (ADS)
Qin, Jiang; Ning, Dongpo; Feng, Yu; Zhang, Junlong; Feng, Shuo; Bao, Wen
2017-06-01
This paper presents the numerical investigation of thermal protection of scramjet strut by opposing jet in supersonic stream of Mach number 6 with a hydrogen fueled scramjet strut model using CFD software. Simulation results indicate that when a small amount of fuel is injected from the nose of the strut, the bow shock is pushed away from the strut, and the heat flux is reduced in the strut, especially at the leading edge. Opposing jet forms a recirculation region near the nozzle so that the strut is covered with low temperature fuel and separated from free stream. An appropriate total pressure ratio can be used to reduce not only aerodynamic heating but also the drag of strut. It is therefore concluded that thermal protection of scramjet strut by opposing jet is one of the promising ways to protect scramjet strut in high enthalpy stream.
A light hydrocarbon fuel processor producing high-purity hydrogen
NASA Astrophysics Data System (ADS)
Löffler, Daniel G.; Taylor, Kyle; Mason, Dylan
This paper discusses the design process and presents performance data for a dual fuel (natural gas and LPG) fuel processor for PEM fuel cells delivering between 2 and 8 kW electric power in stationary applications. The fuel processor resulted from a series of design compromises made to address different design constraints. First, the product quality was selected; then, the unit operations needed to achieve that product quality were chosen from the pool of available technologies. Next, the specific equipment needed for each unit operation was selected. Finally, the unit operations were thermally integrated to achieve high thermal efficiency. Early in the design process, it was decided that the fuel processor would deliver high-purity hydrogen. Hydrogen can be separated from other gases by pressure-driven processes based on either selective adsorption or permeation. The pressure requirement made steam reforming (SR) the preferred reforming technology because it does not require compression of combustion air; therefore, steam reforming is more efficient in a high-pressure fuel processor than alternative technologies like autothermal reforming (ATR) or partial oxidation (POX), where the combustion occurs at the pressure of the process stream. A low-temperature pre-reformer reactor is needed upstream of a steam reformer to suppress coke formation; yet, low temperatures facilitate the formation of metal sulfides that deactivate the catalyst. For this reason, a desulfurization unit is needed upstream of the pre-reformer. Hydrogen separation was implemented using a palladium alloy membrane. Packed beds were chosen for the pre-reformer and reformer reactors primarily because of their low cost, relatively simple operation and low maintenance. Commercial, off-the-shelf balance of plant (BOP) components (pumps, valves, and heat exchangers) were used to integrate the unit operations. The fuel processor delivers up to 100 slm hydrogen >99.9% pure with <1 ppm CO, <3 ppm CO 2. The thermal efficiency is better than 67% operating at full load. This fuel processor has been integrated with a 5-kW fuel cell producing electricity and hot water.
40 CFR 63.10042 - What definitions apply to this subpart?
Code of Federal Regulations, 2013 CFR
2013-07-01
... gas stream. Fossil fuel means natural gas, oil, coal, and any form of solid, liquid, or gaseous fuel... administrative proceeding. Anthracite coal means solid fossil fuel classified as anthracite coal by American... utility steam generating unit meeting the definition of “fossil fuel-fired” that burns coal for more than...
40 CFR 63.10042 - What definitions apply to this subpart?
Code of Federal Regulations, 2012 CFR
2012-07-01
... gas stream. Fossil fuel means natural gas, oil, coal, and any form of solid, liquid, or gaseous fuel... administrative proceeding. Anthracite coal means solid fossil fuel classified as anthracite coal by American... utility steam generating unit meeting the definition of “fossil fuel-fired” that burns coal for more than...
40 CFR 63.10042 - What definitions apply to this subpart?
Code of Federal Regulations, 2014 CFR
2014-07-01
... gas stream. Fossil fuel means natural gas, oil, coal, and any form of solid, liquid, or gaseous fuel... administrative proceeding. Anthracite coal means solid fossil fuel classified as anthracite coal by American... utility steam generating unit meeting the definition of “fossil fuel-fired” that burns coal for more than...
Riparian fuel treatments in the western USA: Challenges and considerations
Kathleen A. Dwire; Kristen E. Meyer; Gregg Riegel; Timothy Burton
2016-01-01
Fuel reduction treatments are being conducted throughout watersheds of the western United States to reduce hazardous fuels in efforts to decrease the risk of high-severity fire. The number of fuel reduction projects that include near-stream environments is increasing, bringing new challenges to riparian management. Riparian areas are protected by administrative...
Pattern-formation under acoustic driving forces
NASA Astrophysics Data System (ADS)
Valverde, Jose Manuel
2015-07-01
Chemical and metallurgical processes enhanced by high intensity acoustic waves, thermoacoustic engines and refrigerators, fuel rods in nuclear reactors, heat exchanger tubes, offshore and vibrating structures, solar thermal collectors, acoustic levitators, microfluidic devices, cycling, musical acoustics, blood flow through veins/arteries, hearing in the mammalian ear, carbon nanotube loudspeakers, etc. The evolution of a myriad of processes involving the oscillation of viscous fluids in the presence of solid boundaries is up to a certain extent influenced by acoustic streaming. In addition to the sound field, viscous energy dissipation at the fluid-solid boundary causes a time-independent fluid circulation, which can lead to a significant enhancement of heat, mass and momentum transfer at large oscillation amplitudes. A particularly relevant phenomenon that can be notably affected by acoustic streaming is the promotion of sound waves by temperature gradients or viceversa (thermoacoustics), which is at the basis of potentially efficient and environmental friendly engines and refrigerators that have attracted a renewed interest in the last years. In the present manuscript, historical developments and the underlying basic physics behind acoustic streaming and thermoacoustics are reviewed from an unifying perspective.
Characterization of Catalyst Materials for Production of Aerospace Fuels
NASA Technical Reports Server (NTRS)
Best, Lauren M.; De La Ree, Ana B.; Hepp, Aloysius F.
2012-01-01
Due to environmental, economic, and security issues, there is a greater need for cleaner alternative fuels. There will undoubtedly be a shift from crude oil to non-petroleum sources as a feedstock for aviation (and other transportation) fuels. Additionally, efforts are concentrated on reducing costs coupled with fuel production from non-conventional sources. One solution to this issue is Fischer-Tropsch gas-to-liquid technology. Fischer-Tropsch processing of synthesis gas (CO/H2) produces a complex product stream of paraffins, olefins, and oxygenated compounds such as alcohols and aldehydes. The Fisher-Tropsch process can produce a cleaner diesel oil fraction with a high cetane number (typically above 70) without any sulfur or aromatic compounds. This process is most commonly catalyzed by heterogeneous (in this case, silver and platinum) catalysts composed of cobalt supported on alumina or unsupported alloyed iron powders. Physisorption, chemisorptions, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) are described to better understand the potential performance of Fischer-Tropsch cobalt on alumina catalysts promoted with silver and platinum. The overall goal is to preferentially produce C8 to C18 paraffin compounds for use as aerospace fuels. Progress towards this goal will eventually be updated and achieved by a more thorough understanding of the characterization of catalyst materials. This work was supported by NASA s Subsonic Fixed Wing and In-situ Resource Utilization projects.
Characterization of Catalyst Materials for Production of Aerospace Fuels
NASA Technical Reports Server (NTRS)
DeLaRee, Ana B.; Hepp, Aloysius F.
2011-01-01
Due to environmental, economic, and security issues, there is a greater need for cleaner alternative fuels. There will undoubtedly be a shift from crude oil to non-petroleum sources as a feedstock for aviation (and other transportation) fuels. Additionally, efforts are concentrated on reducing costs coupled with fuel production from non-conventional sources. One solution to this issue is Fischer-Tropsch gas-to-liquid technology. Fischer-Tropsch processing of synthesis gas (CO/H2) produces a complex product stream of paraffins, olefins, and oxygenated compounds such as alcohols and aldehydes. The Fisher-Tropsch process can produce a cleaner diesel oil fraction with a high cetane number (typically above 70) without any sulfur or aromatic compounds. This process is most commonly catalyzed by heterogeneous (in this case, silver and platinum) catalysts composed of cobalt supported on alumina or unsupported alloyed iron powders. Physisorption, chemisorptions, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) are described to better understand the potential performance of Fischer-Tropsch cobalt on alumina catalysts promoted with silver and platinum. The overall goal is to preferentially produce C8 to C18 paraffin compounds for use as aerospace fuels. Progress towards this goal will eventually be updated and achieved by a more thorough understanding of the characterization of catalyst materials. This work was supported by NASA s Subsonic Fixed Wing and In-situ Resource Utilization projects.
Pattern recognition monitoring of PEM fuel cell
Meltser, M.A.
1999-08-31
The CO-concentration in the H{sub 2} feed stream to a PEM fuel cell stack is monitored by measuring current and voltage behavior patterns from an auxiliary cell attached to the end of the stack. The auxiliary cell is connected to the same oxygen and hydrogen feed manifolds that supply the stack, and discharges through a constant load. Pattern recognition software compares the current and voltage patterns from the auxiliary cell to current and voltage signature determined from a reference cell similar to the auxiliary cell and operated under controlled conditions over a wide range of CO-concentrations in the H{sub 2} fuel stream. 4 figs.
Pattern recognition monitoring of PEM fuel cell
Meltser, Mark Alexander
1999-01-01
The CO-concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and voltage behavior patterns from an auxiliary cell attached to the end of the stack. The auxiliary cell is connected to the same oxygen and hydrogen feed manifolds that supply the stack, and discharges through a constant load. Pattern recognition software compares the current and voltage patterns from the auxiliary cell to current and voltage signature determined from a reference cell similar to the auxiliary cell and operated under controlled conditions over a wide range of CO-concentrations in the H.sub.2 fuel stream.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dr. Sean M. McDeavitt; Thomas J. Downar; Dr. Temitope A. Taiwo
2009-03-01
The U.S. Department of Energy is developing next generation processing methods to recycle uranium and transuranic (TRU) isotopes from spent nuclear fuel. The objective of the 3-year project described in this report was to develop near-term options for storing TRU oxides isolated through the uranium extraction (UREX+) process. More specifically, a Zircaloy matrix cermet was developed as a storage form for transuranics with the understanding that the cermet also has the ability to serve as a inert matrix fuel form for TRU burning after intermediate storage. The goals of this research projects were: 1) to develop the processing steps requiredmore » to transform the effluent TRU nitrate solutions and the spent Xircaloy cladding into a zireonium matrix cermet sotrage form; and 2) to evaluate the impact of phenomena that govern durability of the storage form, material processing, and TRU utiliztion in fast reactor fuel. This report represents a compilation of the results generated under this program. The information is presented as a brief technical narrative in the following sections with appended papers, presentations and academic theses to provide a detailed review of the project's accomplishments.« less
Energy Conversion and Storage Program
NASA Astrophysics Data System (ADS)
Cairns, E. J.
1993-06-01
This report is the 1992 annual progress report for the Energy Conversion and Storage Program, a part of the Energy and Environment Division of the Lawrence Berkeley Laboratory. Work described falls into three broad areas: electrochemistry; chemical applications; and materials applications. The Energy Conversion and Storage Program applies principles of chemistry and materials science to solve problems in several areas: (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes and chemical species, and (5) study and application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Chemical applications research includes topics such as separations, catalysis, fuels, and chemical analyses. Included in this program area are projects to develop improved, energy-efficient methods for processing product and waste streams from synfuel plants, coal gasifiers, and biomass conversion processes. Materials applications research includes evaluation of the properties of advanced materials, as well as development of novel preparation techniques. For example, techniques such as sputtering, laser ablation, and poised laser deposition are being used to produce high-temperature superconducting films.
Technology Horizons: A Vision for Air Force Science and Technology 2010-30
2011-09-01
software, hardware, and networks, it is now recognized as en- compassing the entire system that couples information flow and decision processes across...acceleration, and scramjet cruise. Inward turning inlets and a dual- flow path design allow high volumetric efficiency, and high cruise speed provides...the same time, emerging “third- stream engine architectures” can enable constant-mass- flow engines that can provide further reductions in fuel
Merox catalyst innovation solves difficult kerosene treating problems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Verachtert, T.A.; Salazar, J.R.; Staehle, B.E.
1985-03-01
The UOP* Merox* process has enjoyed more than 25 years of successful commercial application. It is applied to treatment of mercaptanrich hydrocarbon streams ranging from a light gas to liquids as heavy as 350/sup 0/C (650/sup 0/F) endpoint diesel fuel. Although Merox has been applied successfully to many kerosenes, there are kerosenes from certain crudes that could not be treated using the standard Merox system. Recent UOP Merox research has centered on the development of new catalysts. From this research, an improved catalyst system (Merox 10*) for kerosene treatment now makes the Merox process applicable to the sweetening of anymore » kerosene boiling range material from any crude oil source now in production. This Merox catalyst innovation also could replace the more expensive hydrotreating still being used by refiners for reducing the mercaptan content of distillates. This paper discusses the application of the Merox process to the treatment of higher boiling fuels, particularly kerosene and jet fuel; however, it should be understood that the treatment of illuminating kerosene, stove oil, diesel fuel, and light furnace oil is quite similar although generally less complicated. Comparative economics and commercial data are provided for the Merox 10 and conventional fixed bed Merox systems. The well established superior economics of Merox over an equivalent duty hydrotreater are presented.« less
Catalysis in high-temperature fuel cells.
Föger, K; Ahmed, K
2005-02-17
Catalysis plays a critical role in solid oxide fuel cell systems. The electrochemical reactions within the cell--oxygen dissociation on the cathode and electrochemical fuel combustion on the anode--are catalytic reactions. The fuels used in high-temperature fuel cells, for example, natural gas, propane, or liquid hydrocarbons, need to be preprocessed to a form suitable for conversion on the anode-sulfur removal and pre-reforming. The unconverted fuel (economic fuel utilization around 85%) is commonly combusted using a catalytic burner. Ceramic Fuel Cells Ltd. has developed anodes that in addition to having electrochemical activity also are reactive for internal steam reforming of methane. This can simplify fuel preprocessing, but its main advantage is thermal management of the fuel cell stack by endothermic heat removal. Using this approach, the objective of fuel preprocessing is to produce a methane-rich fuel stream but with all higher hydrocarbons removed. Sulfur removal can be achieved by absorption or hydro-desulfurization (HDS). Depending on the system configuration, hydrogen is also required for start-up and shutdown. Reactor operating parameters are strongly tied to fuel cell operational regimes, thus often limiting optimization of the catalytic reactors. In this paper we discuss operation of an authothermal reforming reactor for hydrogen generation for HDS and start-up/shutdown, and development of a pre-reformer for converting propane to a methane-rich fuel stream.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Basha, Omar M.; Keller, Murphy J.; Luebke, David R.
The Ionic Liquid (IL) [hmim][Tf 2N] was used as a physical solvent in an Aspen Plus simulation, employing the Peng-Robinson Equation of State (P-R EOS) with Boston-Mathias (BM) alpha function and standard mixing rules, to develop a conceptual process for CO 2 capture from a shifted warm fuel gas stream produced from Pittsburgh # 8 coal for a 400 MWe power plant. The physical properties of the IL, including density, viscosity, surface tension, vapor pressure and heat capacity were obtained from literature and modeled as a function of temperature. Also, available experimental solubility values for CO 2, H 2, Hmore » 2S, CO, and CH 4 in this IL were compiled and their binary interaction parameters (Δ ij and l ij) were optimized and correlated as functions of temperature. The Span-Wager Equation-of-State EOS was also employed to generate CO 2 solubilities in [hmim][Tf 2N] at high pressures (up to 10 MPa) and temperatures (up to 510 K). The conceptual process developed consisted of 4 adiabatic absorbers (2.4 m ID, 30 m high) arranged in parallel and packed with Plastic Pall Rings of 0.025 m for CO 2 capture; 3 flash drums arranged in series for solvent (IL) regeneration with the pressure-swing option; and a pressure-intercooling system for separating and pumping CO 2 up to 153 bar to the sequestration sites. The compositions of all process streams, CO 2 capture efficiency, and net power were calculated using Aspen Plus simulator. The results showed that, based on the composition of the inlet gas stream to the absorbers, 95.67 mol% of CO 2 was captured and sent to sequestration sites; 99.5 mol% of H 2 was separated and sent to turbines; the solvent exhibited a minimum loss of 0.31 mol%; and the net power balance of the entire system was 30.81 MW. These results indicated that [hmim][Tf 2N] IL could be used as a physical solvent for CO 2 capture from warm shifted fuel gas streams with high efficiency.« less
Stable Isotopic Tracking of Autocthonous Carbon in Two Contrasting Ozark Streams
NASA Astrophysics Data System (ADS)
Ziegler, S.; Brisco-Townsend, S.
2005-05-01
The central role of microbes in biogeochemical processes makes the identification of carbon (C) sources fueling microorganisms critical to our understanding of stream ecosystems. The δ13C of biofilm phospholipid fatty acids (δ13CBPLFA) were determined in experiments conducted from July 2002 through July 2003 using 13C-labeled bicarbonate to track autochthonous C in two streams. In Moore Creek (MC), an agricultural stream, and Huey Hollow (HH), a forested stream, dissolved organic carbon (DOC) was released in light incubations during all seasons and represented >10% biofilm net primary production. The DOC from light incubations was enriched in 13C relative to DOC from dark incubations suggesting algal exudates were a major source of the DOC. The δ13CBPLFA suggest that 13C enriched exudates were not utilized by heterotrophic bacterial components in MC. Autotrophic PLFA from light incubations were more enriched in 13C while heterotrophic bacterial δ13CBPLFA were similar between light and dark incubations. By contrast, both heterotrophic and autotrophic biomarkers were significantly enriched in 13C in light incubations relative to dark incubations conducted in spring and summer in HH. Results suggest the exchange of C between autotrophic and heterotrophic components of biofilm communities differs between nutrient-enriched and depleted streams.
Ekpo, U; Ross, A B; Camargo-Valero, M A; Williams, P T
2016-01-01
Thermal hydrolysis and hydrothermal processing show promise for converting biomass into higher energy density fuels. Both approaches facilitate the extraction of inorganics into the aqueous product. This study compares the behaviour of microalgae, digestate, swine and chicken manure by thermal hydrolysis and hydrothermal processing at increasing process severity. Thermal hydrolysis was performed at 170°C, hydrothermal carbonisation (HTC) was performed at 250°C, hydrothermal liquefaction (HTL) was performed at 350°C and supercritical water gasification (SCWG) was performed at 500°C. The level of nitrogen, phosphorus and potassium in the product streams was measured for each feedstock. Nitrogen is present in the aqueous phase as organic-N and NH3-N. The proportion of organic-N is higher at lower temperatures. Extraction of phosphorus is linked to the presence of inorganics such as Ca, Mg and Fe in the feedstock. Microalgae and chicken manure release phosphorus more easily than other feedstocks. Copyright © 2015. Published by Elsevier Ltd.
Prediction and validation of blowout limits of co-flowing jet diffusion flames -- effect of dilution
DOE Office of Scientific and Technical Information (OSTI.GOV)
Karbasi, M.; Wierzba, I.
1996-10-01
The blowout limits of a co-flowing turbulent methane jet diffusion flame with addition of diluent in either jet fuel or surrounding air stream is studied both analytically and experimentally. Helium, nitrogen and carbon dioxide were employed as the diluents. Experiments indicated that an addition of diluents to the jet fuel or surrounding air stream decreased the stability limit of the jet diffusion flames. The strongest effect was observed with carbon dioxide as the diluent followed by nitrogen and then by helium. A model of extinction based on recognized criterion of the mixing time scale to characteristic combustion time scale ratiomore » using experimentally derived correlations is proposed. It is capable of predicting the large reduction of the jet blowout velocity due to a relatively small increase in the co-flow stream velocity along with an increase in the concentration of diluent in either the jet fuel or surrounding air stream. Experiments were carried out to validate the model. The predicted blowout velocities of turbulent jet diffusion flames obtained using this model are in good agreement with the corresponding experimental data.« less
1981-09-01
Atomi:Mation, Ignition and Combustion of Liquid and Multiphase Fuels in High -Speed Air StreamsIi J. Schetz VPI and State University 9:00 Turbulent Mixing and...Aeronautical Laboratories (AFWAL) 8:35 Injection, Atomt:ation, Ignition and Combustion of Liquid and Multiphase Fuels in High -Speed Air Streams J...State University Transverse injection of liquid and/or liquid -slurry jets into high speed airstreams finds application in several propulsion-related
Valve for fuel pin loading system
Christiansen, David W.
1985-01-01
A cyclone valve surrounds a wall opening through which cladding is projected. An axial valve inlet surrounds the cladding. Air is drawn through the inlet by a cyclone stream within the valve. An inflatable seal is included to physically engage a fuel pin subassembly during loading of fuel pellets.
Blender for Antimisting Kerosene
NASA Technical Reports Server (NTRS)
Parikh, Pradip G.; Sarohia, Virendra; Yavrouian, Andre H.
1987-01-01
Blender continuously disperses controlled amount of flammability-reducing additive into stream of jet fuel. Resulting mixture consists of homogeneous suspension of additive polymer particles in fuel. Particles dissolve within 15 to 30 min, without agitation, forming airplane fuel known as antimisting kerosene which promises to reduce danger from fire in crashes.
NASA Astrophysics Data System (ADS)
Bergeron, P. W.; Corder, R. E.; Hill, A. M.; Lindsey, H.; Lowenstein, M. Z.
1983-02-01
The biomass with which this report is concerned includes aquatic plants, which can be converted into liquid fuels and chemicals; organic wastes (crop residues as well as animal and municipal wastes), from which biogas can be produced via anerobic digestion; and organic or inorganic waste streams, from which hydrogen can be produced by photobiological processes. The Biomass Program Office supports research in three areas which, although distinct, all use living organisms to create the desired products. The Aquatic Species Program (ASP) supports research on organisms that are themselves processed into the final products, while the Anaerobic Digestion (ADP) and Photo/Biological Hydrogen Program (P/BHP) deals with organisms that transform waste streams into energy products. The P/BHP is also investigating systems using water as a feedstock and cell-free systems which do not utilize living organisms. This report summarizes the progress and research accomplishments of the SERI Biomass Program during FY 1982.
Hunt, A.J.
1983-09-13
The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles. 5 figs.
Hunt, Arlon J.
1983-01-01
The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles.
Radiant energy collection and conversion apparatus and method
Hunt, Arlon J.
1982-01-01
The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles.
Radiant energy collection and conversion apparatus and method
Hunt, A.J.
The apparatus for collecting radiant energy and converting to alternate energy forms includes a housing having an interior space and a radiation transparent window allowing solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past the window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles.
Steam Methane Reformation Testing for Air-Independent Solid Oxide Fuel Cell Systems
NASA Technical Reports Server (NTRS)
Mwara, Kamwana N.
2015-01-01
Recently, NASA has been looking into utilizing landers that can be propelled by LOX-CH (sub 4), to be used for long duration missions. Using landers that utilize such propellants, also provides the opportunity to use solid oxide fuel cells as a power option, especially since they are able to process methane into a reactant through fuel reformation. One type of reformation, called steam methane reformation, is a process to reform methane into a hydrogen-rich product by reacting methane and steam (fuel cell exhaust) over a catalyst. A steam methane reformation system could potentially use the fuel cell's own exhaust to create a reactant stream that is hydrogen-rich, and requires less internal reforming of the incoming methane. Also, steam reformation may hold some advantages over other types of reforming, such as partial oxidation (PROX) reformation. Steam reformation does not require oxygen, while up to 25 percent can be lost in PROX reformation due to unusable CO (sub 2) reformation. NASA's Johnson Space Center has conducted various phases of steam methane reformation testing, as a viable solution for in-space reformation. This has included using two different types of catalysts, developing a custom reformer, and optimizing the test system to find the optimal performance parameters and operating conditions.
Solid recovered fuel: An experiment on classification and potential applications.
Bessi, C; Lombardi, L; Meoni, R; Canovai, A; Corti, A
2016-01-01
The residual urban waste of Prato district (Italy) is characterized by a high calorific value that would make it suitable for direct combustion in waste-to-energy plants. Since the area of central Italy lacks this kind of plant, residual municipal waste is quite often allocated to mechanical treatment plants in order to recover recyclable materials (such as metals) and energy content, sending the dry fractions to waste-to-energy plants outside the region. With the previous Italian legislation concerning Refuse Derived Fuels, only the dry stream produced as output by the study case plant, considered in this study, could be allocated to energy recovery, while the other output flows were landfilled. The most recent Italian regulation, introduced a new classification for the fuel streams recovered from waste following the criteria of the European standard (EN 15359:2011), defining the Solid Recovered Fuel (SRF). In this framework, the aim of this study was to check whether the different streams produced as output by the study case plant could be classified as SRF. For this reason, a sampling and analysis campaign was carried out with the purpose of characterizing every single output stream that can be obtained from the study case mechanical treatment plant, when operating it in different ways. The results showed that all the output flows from the study case mechanical treatment plant were classified as SRF, although with a wide quality range. In particular, few streams, of rather poor quality, could be fed to waste-to-energy plants, compatibly with the plant feeding systems. Other streams, with very high quality, were suitable for non-dedicated facilities, such as cement plants or power plants, as a substitute for coal. The implementation of the new legislation has hence the potential for a significant reduction of landfilling, contributing to lowering the overall environmental impact by avoiding the direct impacts of landfilling and by exploiting the beneficial effects of energy recovery from waste. Copyright © 2015 Elsevier Ltd. All rights reserved.
NASA PEMFC Development Background and History
NASA Technical Reports Server (NTRS)
Hoberecht, Mark
2011-01-01
NASA has been developing proton-exchange-membrane (PEM) fuel cell power systems for the past decade, as an upgraded technology to the alkaline fuel cells which presently provide power for the Shuttle Orbiter. All fuel cell power systems consist of one or more fuel cell stacks in combination with appropriate balance-of-plant hardware. Traditional PEM fuel cells are characterized as flow-through, in which recirculating reactant streams remove product water from the fuel cell stack. NASA recently embarked on the development of non-flow-through fuel cell systems, in which reactants are dead-ended into the fuel cell stack and product water is removed by internal wicks. This simplifies the fuel cell power system by eliminating the need for pumps to provide reactant circulation, and mechanical water separators to remove the product water from the recirculating reactant streams. By eliminating these mechanical components, the resulting fuel cell power system has lower mass, volume, and parasitic power requirements, along with higher reliability and longer life. Four vendors have designed and fabricated non-flow-through fuel cell stacks under NASA funding. One of these vendors is considered the "baseline" vendor, and the remaining three vendors are competing for the "alternate" role. Each has undergone testing of their stack hardware integrated with a NASA balance-of-plant. Future Exploration applications for this hardware include primary fuel cells for a Lunar Lander and regenerative fuel cells for Surface Systems.
A novel cell factory for efficient production of ethanol from dairy waste.
Liu, Jianming; Dantoft, Shruti Harnal; Würtz, Anders; Jensen, Peter Ruhdal; Solem, Christian
2016-01-01
Sustainable and economically feasible ways to produce ethanol or other liquid fuels are becoming increasingly relevant due to the limited supply of fossil fuels and the environmental consequences associated with their consumption. Microbial production of fuel compounds has gained a lot of attention and focus has mostly been on developing bio-processes involving non-food plant biomass feedstocks. The high cost of the enzymes needed to degrade such feedstocks into its constituent sugars as well as problems due to various inhibitors generated in pretreatment are two challenges that have to be addressed if cost-effective processes are to be established. Various industries, especially within the food sector, often have waste streams rich in carbohydrates and/or other nutrients, and these could serve as alternative feedstocks for such bio-processes. The dairy industry is a good example, where large amounts of cheese whey or various processed forms thereof are generated. Because of their nutrient-rich nature, these substrates are particularly well suited as feedstocks for microbial production. We have generated a Lactococcus lactis strain which produces ethanol as its sole fermentation product from the lactose contained in residual whey permeate (RWP), by introducing lactose catabolism into a L. lactis strain CS4435 (MG1363 Δ(3) ldh, Δpta, ΔadhE, pCS4268), where the carbon flow has been directed toward ethanol instead of lactate. To achieve growth and ethanol production on RWP, we added corn steep liquor hydrolysate (CSLH) as the nitrogen source. The outcome was efficient ethanol production with a titer of 41 g/L and a yield of 70 % of the theoretical maximum using a fed-batch strategy. The combination of a low-cost medium from industrial waste streams and an efficient cell factory should make the developed process industrially interesting. A process for the production of ethanol using L. lactis and a cheap renewable feedstock was developed. The results demonstrate that it is possible to achieve sustainable bioconversion of waste products from the dairy industry (RWP) and corn milling industry (CSLH) to ethanol and the process developed shows great potential for commercial realization.
Luo, Weifang [Livermore, CA; Stewart, Kenneth D [Valley Springs, CA
2009-11-17
Disclosed is a device for removing trace amounts of ammonia from a stream of gas, particularly hydrogen gas, prepared by a reformation apparatus. The apparatus is used to prevent PEM "poisoning" in a fuel cell receiving the incoming hydrogen stream.
Durham, Michael D.; Stedman, Donald H.; Ebner, Timothy G.; Burkhardt, Mark R.
1991-01-01
A device and method for measuring the concentrations of components of a fluid stream. Preferably, the fluid stream is an in situ gas stream, such as a fossil fuel fired flue gas in a smoke stack. The measurements are determined from the intensity of radiation over a selected range of radiation wavelengths using peak-to-trough calculations. The need for a reference intensity is eliminated.
Biochemical Conversion Processes of Lignocellulosic Biomass to Fuels and Chemicals - A Review.
Brethauer, Simone; Studer, Michael H
2015-01-01
Lignocellulosic biomass - such as wood, agricultural residues or dedicated energy crops - is a promising renewable feedstock for production of fuels and chemicals that is available at large scale at low cost without direct competition for food usage. Its biochemical conversion in a sugar platform biorefinery includes three main unit operations that are illustrated in this review: the physico-chemical pretreatment of the biomass, the enzymatic hydrolysis of the carbohydrates to a fermentable sugar stream by cellulases and finally the fermentation of the sugars by suitable microorganisms to the target molecules. Special emphasis in this review is put on the technology, commercial status and future prospects of the production of second-generation fuel ethanol, as this process has received most research and development efforts so far. Despite significant advances, high enzyme costs are still a hurdle for large scale competitive lignocellulosic ethanol production. This could be overcome by a strategy termed 'consolidated bioprocessing' (CBP), where enzyme production, enzymatic hydrolysis and fermentation is integrated in one step - either by utilizing one genetically engineered superior microorganism or by creating an artificial co-culture. Insight is provided on both CBP strategies for the production of ethanol as well as of advanced fuels and commodity chemicals.
Novel use of geochemical models in evaluating treatment trains for aqueous radioactive waste streams
DOE Office of Scientific and Technical Information (OSTI.GOV)
Abitz, R.J.
1996-12-31
Thermodynamic geochemical models have been applied to assess the relative effectiveness of a variety of reagents added to aqueous waste streams for the removal of radioactive elements. Two aqueous waste streams were examined: effluent derived from the processing of uranium ore and irradiated uranium fuel rods. Simulations of the treatment train were performed to estimate the mass of reagents needed per kilogram of solution, identify pH regions corresponding to solubility minimums, and predict the identity and quantity of precipitated solids. Results generated by the simulations include figures that chart the chemical evolution of the waste stream as reagents are addedmore » and summary tables that list mass balances for all reagents and radioactive elements of concern. Model results were used to set initial reagent levels for the treatment trains, minimizing the number of bench-scale tests required to bring the treatment train up to full-scale operation. Additionally, presentation of modeling results at public meetings helps to establish good faith between the federal government, industry, concerned citizens, and media groups. 18 refs., 3 figs., 1 tab.« less
Apparatus and method for removing particulate deposits from high temperature filters
Nakaishi, Curtis V.; Holcombe, Norman T.; Micheli, Paul L.
1992-01-01
A combustion of a fuel-air mixture is used to provide a high-temperature and high-pressure pulse of gaseous combustion products for the back-flush cleaning of ceramic filter elements contained in a barrier filter system and utilized to separate particulates from particulate-laden process gases at high temperature and high pressure. The volume of gaseous combustion products provided by the combustion of the fuel-air mixture is preferably divided into a plurality of streams each passing through a sonic orifice and conveyed to the open end of each filter element as a high pressure pulse which passes through the filter elements and dislodges dust cake supported on a surface of the filter element.
Lu, Hui; Rihko-Struckmann, Liisa; Sundmacher, Kai
2011-10-28
The spontaneous oscillations of the cell voltage and output power density of a PEMFC (with PtRu/C anode) using CO-containing H(2) streams as anodic fuels have been observed during galvanostatic operating. It is ascribed to the dynamic coupling of the CO adsorption (poisoning) and the electrochemical CO oxidation (reactivating) processes in the anode chamber of the single PEMFC. Accompanying the cell voltage and power density oscillations, the discrete CO concentration oscillations at the anode outlet of the PEMFC were also detected, which directly confirms the electrochemical CO oxidation taking place in the anode chamber during galvanostatic operating. This journal is © the Owner Societies 2011
Reduced No.sub.x combustion method
Delano, Mark A.
1991-01-01
A combustion method enabling reduced NO.sub.x formation wherein fuel and oxidant are separately injected into a combustion zone in a defined velocity relation, combustion gases are aspirated into the oxidant stream prior to intermixture with the fuel, and the fuel is maintained free from contact with oxygen until the intermixture.
Characterization of Used Nuclear Fuel with Multivariate Analysis for Process Monitoring
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dayman, Kenneth J.; Coble, Jamie B.; Orton, Christopher R.
2014-01-01
The Multi-Isotope Process (MIP) Monitor combines gamma spectroscopy and multivariate analysis to detect anomalies in various process streams in a nuclear fuel reprocessing system. Measured spectra are compared to models of nominal behavior at each measurement location to detect unexpected changes in system behavior. In order to improve the accuracy and specificity of process monitoring, fuel characterization may be used to more accurately train subsequent models in a full analysis scheme. This paper presents initial development of a reactor-type classifier that is used to select a reactor-specific partial least squares model to predict fuel burnup. Nuclide activities for prototypic usedmore » fuel samples were generated in ORIGEN-ARP and used to investigate techniques to characterize used nuclear fuel in terms of reactor type (pressurized or boiling water reactor) and burnup. A variety of reactor type classification algorithms, including k-nearest neighbors, linear and quadratic discriminant analyses, and support vector machines, were evaluated to differentiate used fuel from pressurized and boiling water reactors. Then, reactor type-specific partial least squares models were developed to predict the burnup of the fuel. Using these reactor type-specific models instead of a model trained for all light water reactors improved the accuracy of burnup predictions. The developed classification and prediction models were combined and applied to a large dataset that included eight fuel assembly designs, two of which were not used in training the models, and spanned the range of the initial 235U enrichment, cooling time, and burnup values expected of future commercial used fuel for reprocessing. Error rates were consistent across the range of considered enrichment, cooling time, and burnup values. Average absolute relative errors in burnup predictions for validation data both within and outside the training space were 0.0574% and 0.0597%, respectively. The errors seen in this work are artificially low, because the models were trained, optimized, and tested on simulated, noise-free data. However, these results indicate that the developed models may generalize well to new data and that the proposed approach constitutes a viable first step in developing a fuel characterization algorithm based on gamma spectra.« less
IMPACT OF FISSION PRODUCTS IMPURITY ON THE PLUTONIUM CONTENT IN PWR MOX FUELS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gilles Youinou; Andrea Alfonsi
2012-03-01
This report presents the results of a neutronics analysis done in response to the charter IFCA-SAT-2 entitled 'Fuel impurity physics calculations'. This charter specifies that the separation of the fission products (FP) during the reprocessing of UOX spent nuclear fuel assemblies (UOX SNF) is not perfect and that, consequently, a certain amount of FP goes into the Pu stream used to fabricate PWR MOX fuel assemblies. Only non-gaseous FP have been considered (see the list of 176 isotopes considered in the calculations in Appendix 1). This mixture of Pu and FP is called PuFP. Note that, in this preliminary analysis,more » the FP losses are considered element-independent, i.e., for example, 1% of FP losses mean that 1% of all non-gaseous FP leak into the Pu stream.« less
2010-05-15
flow and decision processes across the air and space domains. It thus comprises traditional wired and fiber-optic computer networks based on...dual flow path design allow high volumetric efficiency, and high cruise speed provides significantly increased survivability. Vertical takeoff...emerging “third-stream engine architectures” can enable for constant mass flow engines that can provide further reductions in fuel consumption. A wide
Refinery Integration of By-Products from Coal-Derived Jet Fuels
DOE Office of Scientific and Technical Information (OSTI.GOV)
Caroline E. Burgess Clifford; Andre Boehman; Chunshan Song
2006-05-17
This report summarizes the accomplishments toward project goals during the first six months of the third year of the project to assess the properties and performance of coal based products. These products are in the gasoline, diesel and fuel oil range and result from coal based jet fuel production from an Air Force funded program. Specific areas of progress include generation of coal based material that has been fractionated into the desired refinery cuts, acquisition and installation of a research gasoline engine, and modification of diesel engines for use in evaluating diesel produced in the project. Characterization of the gasolinemore » fuel indicates a dominance of single ring alkylcycloalkanes that have a low octane rating; however, blends containing these compounds do not have a negative effect upon gasoline when blended in refinery gasoline streams. Characterization of the diesel fuel indicates a dominance of 3-ring aromatics that have a low cetane value; however, these compounds do not have a negative effect upon diesel when blended in refinery diesel streams. The desulfurization of sulfur containing components of coal and petroleum is being studied so that effective conversion of blended coal and petroleum streams can be efficiently converted to useful refinery products. Equipment is now in place to begin fuel oil evaluations to assess the quality of coal based fuel oil. Combustion and characterization of fuel oil indicates that the fuel is somewhere in between a No. 4 and a No. 6 fuel oil. Emission testing indicates the fuel burns similarly to these two fuels, but trace metals for the coal-based material are different than petroleum-based fuel oils. Co-coking studies using cleaned coal are highly reproducible in the pilot-scale delayed coker. Evaluation of the coke by Alcoa, Inc. indicated that while the coke produced is of very good quality, the metals content of the carbon is still high in iron and silica. Coke is being evaluated for other possible uses. Methods to reduce metal content are being evaluated.« less
Solid-shape energy fuels from recyclable municipal solid waste and plastics
NASA Astrophysics Data System (ADS)
Gug, Jeongin
Diversion of waste streams, such as plastics, wood and paper, from municipal landfills and extraction of useful materials from landfills is an area of increasing interest across the country, especially in densely populated areas. One promising technology for recycling MSW (municipal solid waste) is to burn the high energy content components in standard coal boilers. This research seeks to reform wastes into briquette that are compatible with typical coal combustion processes. In order to comply with the standards of coal-fired power plants, the feedstock must be mechanically robust, moisture resistance, and retain high fuel value. Household waste with high paper and fibers content was used as the base material for this study. It was combined with recyclable plastics such as PE, PP, PET and PS for enhanced binding and energy efficiency. Fuel pellets were processed using a compression molding technique. The resulting moisture absorption, proximate analysis from burning, and mechanical properties were investigated after sample production and then compared with reference data for commercial coals and biomass briquettes. The effects of moisture content, compression pressure and processing temperature were studied to identify the optimal processing conditions with water uptake tests for the durability of samples under humid conditions and burning tests to examine the composition of samples. Lastly, mechanical testing revealed the structural stability of solid fuels. The properties of fuel briquettes produced from waste and recycled plastics improved with higher processing temperature but without charring the material. Optimization of moisture content and removal of air bubbles increased the density, stability and mechanical strength. The sample composition was found to be more similar to biomass fuels than coals because the majority of the starting material was paper-based solid waste. According to the proximate analysis results, the waste fuels can be expected to have low temperature ignition, less char formation and reduced CO2 emission with the high heating energy value similar to coal. It is concluded that solid fuels from paper based waste and plastics can be a good energy resource as an alternative and sustainable fuel, which may help to alleviate the environmental problems related to landfill space at the same time.
Experimental verification of the thermodynamic properties for a jet-A fuel
NASA Technical Reports Server (NTRS)
Graciasalcedo, Carmen M.; Brabbs, Theodore A.; Mcbride, Bonnie J.
1988-01-01
Thermodynamic properties for a Jet-A fuel were determined by Shell Development Company in 1970 under a contract for NASA Lewis Research Center. The polynomial fit necessary to include Jet-A fuel (liquid and gaseous phases) in the library of thermodynamic properties of the NASA Lewis Chemical Equilibrium Program is calculated. To verify the thermodynamic data, the temperatures of mixtures of liquid Jet-A injected into a hot nitrogen stream were experimentally measured and compared to those calculated by the program. Iso-octane, a fuel for which the thermodynamic properties are well known, was used as a standard to calibrate the apparatus. The measured temperatures for the iso-octane/nitrogen mixtures reproduced the calculated temperatures except for a small loss due to the non-adiabatic behavior of the apparatus. The measurements for Jet-A were corrected for this heat loss and showed excellent agreement with the calculated temperatures. These experiments show that this process can be adequately described by the thermodynamic properties fitted for the Chemical Equilibrium Program.
Durham, M.D.; Stedman, D.H.; Ebner, T.G.; Burkhardt, M.R.
1991-12-03
A device and method are described for measuring the concentrations of components of a fluid stream. Preferably, the fluid stream is an in-situ gas stream, such as a fossil fuel fired flue gas in a smoke stack. The measurements are determined from the intensity of radiation over a selected range of radiation wavelengths using peak-to-trough calculations. The need for a reference intensity is eliminated. 15 figures.
Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Oinas, Pekka
2016-01-01
In the production of solid recovered fuel (SRF), certain waste components have excessive influence on the quality of product. The proportion of rubber, plastic (hard) and certain textiles was found to be critical as to the elemental quality of SRF. The mass flow of rubber, plastic (hard) and textiles (to certain extent, especially synthetic textile) components from input waste stream into the output streams of SRF production was found to play the decisive role in defining the elemental quality of SRF. This paper presents the mass flow of polluting and potentially toxic elements (PTEs) in SRF production. The SRF was produced from municipal solid waste (MSW) through mechanical treatment (MT). The results showed that of the total input chlorine content to process, 55% was found in the SRF and 30% in reject material. Of the total input arsenic content, 30% was found in the SRF and 45% in fine fraction. In case of cadmium, lead and mercury, of their total input content to the process, 62%, 38% and 30%, respectively, was found in the SRF. Among the components of MSW, rubber material was identified as potential source of chlorine, containing 8.0 wt.% of chlorine. Plastic (hard) and textile components contained 1.6 and 1.1. wt.% of chlorine, respectively. Plastic (hard) contained higher lead and cadmium content compared with other waste components, i.e. 500 mg kg(-1) and 9.0 mg kg(-1), respectively. © The Author(s) 2015.
Mixing Enhancement in a Lobed Injector
NASA Technical Reports Server (NTRS)
Smith, L. L.; Majamaki, A. J.; Lam, I. T.; Delabroy, O.; Karagozian, A. R.; Marble, F. E.; Smith, O. I.
1997-01-01
An experimental investigation of the non-reactive mixing processes associated with a lobed fuel injector in a coflowing air stream is presented. The lobed fuel injector is a device which generates streamwise vorticity, producing high strain rates which can enhance the mixing of reactants while delaying ignition in a controlled manner. The lobed injectors examined in the present study consist of two corrugated plates between which a fuel surrogate, CO2, is injected into coflowing air. Acetone is seeded in the CO2 supply as a fuel marker. Comparison of two alternative lobed injector geometries is made with a straight fuel injector to determine net differences in mixing and strain fields due to streamwise vorticity generation. Planar laser-induced fluorescence (PLIF) of the seeded acetone yields two-dimensional images of the scalar concentration field at various downstream locations, from which local mixing and scalar dissipation rates are computed. It is found that the lobed injector geometry can enhance molecular mixing and create a highly strained flowfield, and that the strain rates generated by scalar energy dissipation can potentially delay ignition in a reacting flowfield.
Chemical Technology Division annual technical report, 1990
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1991-05-01
Highlights of the Chemical Technology (CMT) Division's activities during 1990 are presented. In this period, CMT conducted research and development in the following areas: (1) electrochemical technology, including advanced batteries and fuel cells; (2) technology for coal- fired magnetohydrodynamics and fluidized-bed combustion; (3) methods for recovery of energy from municipal waste and techniques for treatment of hazardous organic waste; (4) the reaction of nuclear waste glass and spent fuel under conditions expected for a high-level waste repository; (5) processes for separating and recovering transuranic elements from nuclear waste streams, concentrating plutonium solids in pyrochemical residues by aqueous biphase extraction, andmore » treating natural and process waters contaminated by volatile organic compounds; (6) recovery processes for discharged fuel and the uranium blanket in the Integral Fast Reactor (IFR); (7) processes for removal of actinides in spent fuel from commercial water-cooled nuclear reactors and burnup in IFRs; and (8) physical chemistry of selected materials in environments simulating those of fission and fusion energy systems. The Division also has a program in basic chemistry research in the areas of fluid catalysis for converting small molecules to desired products; materials chemistry for superconducting oxides and associated and ordered solutions at high temperatures; interfacial processes of importance to corrosion science, high-temperature superconductivity, and catalysis; and the geochemical processes responsible for trace-element migration within the earth's crust. The Analytical Chemistry Laboratory in CMT provides a broad range of analytical chemistry support services to the scientific and engineering programs at Argonne National Laboratory (ANL). 66 refs., 69 figs., 6 tabs.« less
Full-Authority Fault-Tolerant Electronic Engine Control Systems for Variable Cycle Engines.
1981-12-01
Geometry or Fuel Flow Scheduled as a Function of Engine State, i.e. FIGV = f( N1 C2 ) Closed Loop - Geometry or Fuel Flow Modulated To Maintain an Engine...Low Pressure Turbine Inlet Area (A41) Closed Loop (Integral) N2, T22 Core Stream Exhaust Nozzle Area (AJE) Closed Loop (Integral) N1 , T2 Duct Stream...to remain at the breakpoint value while low rotor speed reference ( N1 reference) is scheduled to decrease as a function of power lever angle (PLA), to
2011-06-01
Union is willing to reduce its greenhouse gas emissions by 20% by 2020 and increase the overall share of renewables by 20% by 2020,4 fossil fuels will...Europe‘s climate change opportunity.‖ It addresses two key targets—the reduction of 20% of all greenhouse gas emissions by 2020 and a 20% share of the...fuels are accountable for the biggest part of greenhouse gas emissions , and invest in new CO2- 88
Recycled Uranium Mass Balance Project Y-12 National Security Complex Site Report
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
2000-12-01
This report has been prepared to summarize the findings of the Y-12 National Security Complex (Y-12 Complex) Mass Balance Project and to support preparation of associated U. S. Department of Energy (DOE) site reports. The project was conducted in support of DOE efforts to assess the potential for health and environmental issues resulting from the presence of transuranic (TRU) elements and fission products in recycled uranium (RU) processed by DOE and its predecessor agencies. The United States government used uranium in fission reactors to produce plutonium and tritium for nuclear weapons production. Because uranium was considered scarce relative to demandmore » when these operations began almost 50 years ago, the spent fuel from U.S. fission reactors was processed to recover uranium for recycling. The estimated mass balance for highly enriched RU, which is of most concern for worker exposure and is the primary focus of this project, is summarized in a table. A discrepancy in the mass balance between receipts and shipments (plus inventory and waste) reflects an inability to precisely distinguish between RU and non-RU shipments and receipts involving the Y-12 Complex and Savannah River. Shipments of fresh fuel (non-RU) and sweetener (also non-RU) were made from the Y-12 Complex to Savannah River along with RU shipments. The only way to distinguish between these RU and non-RU streams using available records is by enrichment level. Shipments of {le}90% enrichment were assumed to be RU. Shipments of >90% enrichment were assumed to be non-RU fresh fuel or sweetener. This methodology using enrichment level to distinguish between RU and non-RU results in good estimates of RU flows that are reasonably consistent with Savannah River estimates. Although this is the best available means of distinguishing RU streams, this method does leave a difference of approximately 17.3 MTU between receipts and shipments. Slightly depleted RU streams received by the Y-12 Complex from ORGDP and PGDP are believed to have been returned to the shipping site or disposed of as waste on the Oak Ridge Reservation. No evidence of Y-12 Complex processing of this material was identified in the historical records reviewed by the Project Team.« less
Anaerobic fermentation of glycerol: a path to economic viability for the biofuels industry.
Yazdani, Syed Shams; Gonzalez, Ramon
2007-06-01
Although biofuels such as biodiesel and bioethanol represent a secure, renewable and environmentally safe alternative to fossil fuels, their economic viability is a major concern. The implementation of biorefineries that co-produce higher value products along with biofuels has been proposed as a solution to this problem. The biorefinery model would be especially advantageous if the conversion of byproducts or waste streams generated during biofuel production were considered. Glycerol-rich streams generated in large amounts by the biofuels industry, especially during the production of biodiesel, present an excellent opportunity to establish biorefineries. Once considered a valuable 'co-product', crude glycerol is rapidly becoming a 'waste product' with a disposal cost attributed to it. Given the highly reduced nature of carbon in glycerol and the cost advantage of anaerobic processes, fermentative metabolism of glycerol is of special interest. This review covers the anaerobic fermentation of glycerol in microbes and the harnessing of this metabolic process to convert abundant and low-priced glycerol streams into higher value products, thus creating a path to viability for the biofuels industry. Special attention is given to products whose synthesis from glycerol would be advantageous when compared with their production from common sugars.
NASA Technical Reports Server (NTRS)
Cullom, R. R.; Johnson, R. L.
1977-01-01
The specific fuel consumption of a low-bypass-ratio, confluent-flow, turbofan engine was measured with and without a mixer installed. Tests were conducted for flight Mach numbers from 0.3 to 1.4 and altitudes from 10,670 to 14,630 meters (35,000 to 48,000 ft) for core-stream-to-fan-stream temperature ratios of 2.0 and 2.5 and mixing-length-to-diameter ratios of 0.95 and 1.74. For these test conditions, the reduction in specific fuel consumption varied from 2.5 percent to 4.0 percent. Pressure loss measurements as well as temperature and pressure surveys at the mixer inlet, the mixer exit, and the nozzle inlet were made.
Cold Regions Environmental Considerations
2009-02-03
braided streams, variable discharge, seasonal breakup) limited seasonally limited abundant Hydrology (frozen lakes and bogs) not present seasonally...fuel hoses may crack increasing the potential for fuel spills. Extreme care must be used when handling cables at cold temperatures, protecting the
DOE Office of Scientific and Technical Information (OSTI.GOV)
Troy G. Garn; Mitchell R. Greenhalgh; Jack D. Law
2013-10-01
The release of volatile radionuclides generated during Used Nuclear Fuel reprocessing in the US will most certainly need to be controlled to meet US regulatory emission limits. A US DOE sponsored Off-Gas Sigma Team has been tasked with a multi-lab collaborative research and development effort to investigate and evaluate emissions and immobilization control technologies for the volatile radioactive species generated from commercial Used Nuclear Fuel (UNF) Reprocessing. Physical Adsorption technology is a simpler and potential economical alternative to cryogenic distillation processes that can be used for the capture of krypton and xenon and has resulted in a novel composite sorbentmore » development procedure using synthesized mordenite as the active material. Utilizing the sorbent development procedure, INL sigma team members have developed two composite sorbents that have been evaluated for krypton and xenon capacities at ambient and 191 K temperature using numerous test gas compositions. Adsorption isotherms have been generated to predict equilibration and maximum capacities enabling modeling to support process equipment scale-up.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Troy G. Garn; Mitchell R. Greenhalgh; Jack D. Law
2013-09-01
The release of volatile radionuclides generated during Used Nuclear Fuel reprocessing in the US will most certainly need to be controlled to meet US regulatory emission limits. A US DOE sponsored Off-Gas Sigma Team has been tasked with a multi-lab collaborative research and development effort to investigate and evaluate emissions and immobilization control technologies for the volatile radioactive species generated from commercial Used Nuclear Fuel (UNF) Reprocessing. Physical Adsorption technology is a simpler and potential economical alternative to cryogenic distillation processes that can be used for the capture of krypton and xenon and has resulted in a novel composite sorbentmore » development procedure using synthesized mordenite as the active material. Utilizing the sorbent development procedure, INL sigma team members have developed two composite sorbents that have been evaluated for krypton and xenon capacities at ambient and 191 K temperature using numerous test gas compositions. Adsorption isotherms have been generated to predict equilibration and maximum capacities enabling modeling to support process equipment scale-up.« less
Evaluation of thermal loading on a methane injector at high pressure and temperature
NASA Technical Reports Server (NTRS)
Harvin, Stephen F.
1990-01-01
Experimental and numerical analyses are conducted to determine the surface temperature on a methane fuel injector used to produce a high enthalpy test stream for a combustion-fed subscale wind tunnel facility. It was found that the ratio of the methane fuel injection velocity to the air stream velocity is a significant factor in the production of high injector surface temperatures which lead to rapid deterioration of the fuel injector structure. The numerical code utilized for the computational analysis was found to be representative of the experimentally measured data since the experimental trends were reproduced by the numerical simulation. The quantitative accuracy of the numerical predictions could not be assessed from the data gathered because of the difficulty of making a noninterfering injector surface temperature measurement. The numerical code can be used for parametric evaluation of combustor parameters and thus will serve as an important tool in the design of such fuel injector systems.
Hoffmann, Jessica; Rudra, Souman; Toor, Saqib S; Holm-Nielsen, Jens Bo; Rosendahl, Lasse A
2013-02-01
Initial process studies carried out in Aspen Plus on an integrated thermochemical conversion process are presented herein. In the simulations, a hydrothermal liquefaction (HTL) plant is combined with a biogas plant (BP), such that the digestate from the BP is converted to a biocrude in the HTL process. This biorefinery concept offers a sophisticated and sustainable way of converting organic residuals into a range of high-value biofuel streams in addition to combined heat and power (CHP) production. The primary goal of this study is to provide an initial estimate of the feasibility of such a process. By adding a diesel-quality-fuel output to the process, the product value is increased significantly compared to a conventional BP. An input of 1000 kg h(-1) manure delivers approximately 30-38 kg h(-1) fuel and 38-61 kg h(-1) biogas. The biogas can be used to upgrade the biocrude, to supply the gas grid or for CHP. An estimated 62-84% of the biomass energy can be recovered in the biofuels. Copyright © 2012 Elsevier Ltd. All rights reserved.
Combined goal gasifier and fuel cell system and method
Gmeindl, Frank D.; Geisbrecht, Rodney A.
1990-01-01
A molten carbonate fuel cell is combined with a catalytic coal or coal char gasifier for providing the reactant gases comprising hydrogen, carbon monoxide and carbon dioxide used in the operation of the fuel cell. These reactant gases are stripped of sulfur compounds and particulate material and are then separated in discrete gas streams for conveyance to appropriate electrodes in the fuel cell. The gasifier is arranged to receive the reaction products generated at the anode of the fuel cell by the electricity-producing electrochemical reaction therein. These reaction products from the anode are formed primarily of high temperature steam and carbon dioxide to provide the steam, the atmosphere and the heat necessary to endothermically pyrolyze the coal or char in the presence of a catalyst. The reaction products generated at the cathode are substantially formed of carbon dioxide which is used to heat air being admixed with the carbon dioxide stream from the gasifier for providing the oxygen required for the reaction in the fuel cell and for driving an expansion device for energy recovery. A portion of this carbon dioxide from the cathode may be recycled into the fuel cell with the air-carbon dioxide mixture.
NASA Technical Reports Server (NTRS)
Tacina, R.
1976-01-01
A premixing-prevaporizing fuel system to be used with a catalytic combustor was evaluated for possible application in an automotive gas turbine. Spatial fuel distribution and degree of vaporization were measured using jet A fuel. Two types of air blast injectors were tested, a splash groove injector and a multiple jet cross stream injector. Air swirlers with vane angles of 15 deg and 30 deg were used to improve the spatial fuel distribution in a 12 cm diameter tubular rig. Distribution and vaporization measurements were made 35.5 cm downstream of the injector. The spatial fuel distribution was nearly uniform with the multiple jet contrastream injector and the splash-groove injector with a 30 deg air swirler. The vaporization was nearly 100 percent at an inlet air temperature of 600 K, and at 800 K inlet air temperature fuel oxidation reactions were observed. The total pressure loss was less than 0.5 percent of the total pressure for the multiple jet cross stream injector and the splash groove injector (without air swirler) and less than 1 percent for the splash groove with a 30 deg air swirler.
Sederquist, Richard A.; Szydlowski, Donald F.; Sawyer, Richard D.
1983-01-01
A system is disclosed for removing electrolyte from a fuel cell gas stream. The gas stream containing electrolyte vapor is supercooled utilizing conventional heat exchangers and the thus supercooled gas stream is passed over high surface area passive condensers. The condensed electrolyte is then drained from the condenser and the remainder of the gas stream passed on. The system is particularly useful for electrolytes such as phosphoric acid and molten carbonate, but can be used for other electrolyte cells and simple vapor separation as well.
Sederquist, R.A.; Szydlowski, D.F.; Sawyer, R.D.
1983-02-08
A system is disclosed for removing electrolyte from a fuel cell gas stream. The gas stream containing electrolyte vapor is supercooled utilizing conventional heat exchangers and the thus supercooled gas stream is passed over high surface area passive condensers. The condensed electrolyte is then drained from the condenser and the remainder of the gas stream passed on. The system is particularly useful for electrolytes such as phosphoric acid and molten carbonate, but can be used for other electrolyte cells and simple vapor separation as well. 3 figs.
DOE Office of Scientific and Technical Information (OSTI.GOV)
da Costa Sousa, Leonardo; Foston, Marcus; Bokade, Vijay
One of the key challenges facing lignin conversion to fuels and chemicals is related to the level of carbohydrate and ash impurities found in extracted lignin. Structural modifications of lignin may also occur as a result of biomass pretreatment and harsh lignin extraction protocols. Extractive-Ammonia (EA) is a new pretreatment technology that uses liquid ammonia to cleave lignin–carbohydrate complexes, decrystallize cellulose, solubilize lignin, and selectively extract lignin from lignocellulosic biomass, enabling better utilization of both lignin and carbohydrate components in a biorefinery. The EA-based biorefinery produces two different lignin-rich streams, with different properties, that could potentially be upgraded to fuelsmore » and chemicals using green processes. Here, a water/ethanol-based fractionation method was developed to enrich the ammonia-soluble extractives, resulting in a major product stream containing 92% lignin. Detailed characterization of the various streams resulting from EA treatment, including compositional analysis, structural characterization by nuclear magnetic resonance (NMR) spectrometry, elemental analysis, molecular weight analysis, and thermo-gravimetric analysis provides a broad evaluation of the EA-derived lignin product stream structures and properties, assessing their potential for commercial applications. In conclusion, EA-derived lignins preserve much of lignin's functionality, including the sensitive β-aryl ether units. Furthermore, we observed nitrogen incorporation in the lignin-rich streams, notably due to the presence of hydroxycinnamoyl amides formed during ammonia pretreatment.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Melaina, Marc; Saur, Genevieve; Ramsden, Todd
2015-05-28
This presentation summarizes NREL's hydrogen and fuel cell analysis work in three areas: resource potential, greenhouse gas emissions and cost of delivered energy, and influence of auxiliary revenue streams. NREL's hydrogen and fuel cell analysis projects focus on low-carbon and economic transportation and stationary fuel cell applications. Analysis tools developed by the lab provide insight into the degree to which bridging markets can strengthen the business case for fuel cell applications.
Soloveichik, Grigorii L
2014-01-01
The advantages of liquid fuel cells (LFCs) over conventional hydrogen-oxygen fuel cells include a higher theoretical energy density and efficiency, a more convenient handling of the streams, and enhanced safety. This review focuses on the use of different types of organic fuels as an anode material for LFCs. An overview of the current state of the art and recent trends in the development of LFC and the challenges of their practical implementation are presented.
Schuetz, Mark A.
1983-01-01
A burner assembly provides for 100% premixing of fuel and air by drawing the air into at least one high velocity stream of fuel without power assist. Specifically, the nozzle assembly for injecting the fuel into a throat comprises a plurality of nozzles in a generally circular array. Preferably, swirl is imparted to the air/fuel mixture by angling the nozzles. The diffuser comprises a conical primary diffuser followed by a cusp diffuser.
Effects of fire and fuels management on water quality in eastern North America
R. K. Kolka
2012-01-01
Fuels management, especially prescribed fire, can have direct impacts on aquatic resources through deposition of ash to surface waters. On the terrestrial side, fuels management leads to changes in vegetative structure and potentially soil properties that affect ecosystem cycling of water and inorganic and organic constituents. Because surface water systems (streams,...
USDA-ARS?s Scientific Manuscript database
Biochemical conversion of biomass to fuels or chemicals is often hampered by the presence of inhibitory compounds contained in sugar streams derived from lignocellulosic biomass. Dilute acid pretreatment, in particular, generates numerous fermentation inhibitors including 2-furaldehyde (furfural) a...
Organic waste as a sustainable feedstock for platform chemicals.
Coma, M; Martinez-Hernandez, E; Abeln, F; Raikova, S; Donnelly, J; Arnot, T C; Allen, M J; Hong, D D; Chuck, C J
2017-09-21
Biorefineries have been established since the 1980s for biofuel production, and there has been a switch lately from first to second generation feedstocks in order to avoid the food versus fuel dilemma. To a lesser extent, many opportunities have been investigated for producing chemicals from biomass using by-products of the present biorefineries, simple waste streams. Current facilities apply intensive pre-treatments to deal with single substrate types such as carbohydrates. However, most organic streams such as municipal solid waste or algal blooms present a high complexity and variable mixture of molecules, which makes specific compound production and separation difficult. Here we focus on flexible anaerobic fermentation and hydrothermal processes that can treat complex biomass as a whole to obtain a range of products within an integrated biorefinery concept.
Organic waste as a sustainable feedstock for platform chemicals
Martinez-Hernandez, E.; Abeln, F.; Raikova, S.; Donnelly, J.; Arnot, T. C.; Allen, M. J.; Hong, D. D.; Chuck, C. J.
2017-01-01
Biorefineries have been established since the 1980s for biofuel production, and there has been a switch lately from first to second generation feedstocks in order to avoid the food versus fuel dilemma. To a lesser extent, many opportunities have been investigated for producing chemicals from biomass using by-products of the present biorefineries, simple waste streams. Current facilities apply intensive pre-treatments to deal with single substrate types such as carbohydrates. However, most organic streams such as municipal solid waste or algal blooms present a high complexity and variable mixture of molecules, which makes specific compound production and separation difficult. Here we focus on flexible anaerobic fermentation and hydrothermal processes that can treat complex biomass as a whole to obtain a range of products within an integrated biorefinery concept. PMID:28654113
NASA Technical Reports Server (NTRS)
Locke, Randy J.; Hicks, Yolanda R.; Anderson, Robert C.; deGroot, Wilhelmus A.
2001-01-01
The emphasis of combustion research efforts at NASA Glenn Research Center (GRC) is on collaborating with industry to design and test gas-turbine combustors and subcomponents for both sub- and supersonic applications. These next-generation aircraft combustors are required to meet strict international environmental restrictions limiting emissions. To meet these goals, innovative combustor concepts require operation at temperatures and pressures far exceeding those of cur-rent designs. New and innovative diagnostic tools are necessary to characterize these flow streams since existing methods are inadequate. The combustion diagnostics team at GRC has implemented a suite of highly sensitive, nonintrusive optical imaging methods to diagnose the flowfields of these new engine concepts. By using optically accessible combustors and flametubes, imaging of fuel and intermediate combustion species via planar laser-induced fluorescence (PLIF) at realistic pressures are now possible. Direct imaging of the fuel injection process through both planar Mie scattering and PLIF methods is also performed. Additionally, a novel combination of planar fuel fluorescence imaging and computational analysis allows a 3-D examination of the flowfield, resulting in spatially and temporally resolved fuel/air volume distribution maps. These maps provide detailed insight into the fuel injection process at actual conditions, thereby greatly enhancing the evaluation of fuel injector performance and other combustion phenomena. Stable species such as CO2, O2, N2O. and hydrocarbons are also investigated by a newly demonstrated 1-D, spontaneous Raman spectroscopic method. This visible wavelength Raman technique allows the acquisition of quantitative. stable species concentration measurements from the flow.
NASA Technical Reports Server (NTRS)
Locke, R. J.; Hicks, Y. R.; Anderson, R. C.; deGroot, W. A.
2000-01-01
The emphasis of combustion research efforts at NASA Glenn Research Center (GRC) is on collaborating with industry to design and test gas-turbine combustors and subcomponents for both sub- and supersonic applications. These next-generation aircraft combustors are required to meet strict international environmental restrictions limiting emissions. To meet these goals, innovative combustor concepts require operation at temperatures and pressures far exceeding those of current designs. New and innovative diagnostic tools are necessary to characterize these flow streams since existing methods are inadequate. The combustion diagnostics team at GRC has implemented a suite of highly sensitive, nonintrusive optical imaging methods to diagnose the flowfields of these new engine concepts. By using optically accessible combustors and flame-tubes, imaging of fuel and intermediate combustion species via planar laser-induced fluorescence (PLIF) at realistic pressures are now possible. Direct imaging of the fuel injection process through both planar Mie scattering and PLIF methods is also performed. Additionally, a novel combination of planar fuel fluorescence imaging and computational analysis allows a 3-D examination of the flowfield, resulting in spatially and temporally resolved fuel/air volume distribution maps. These maps provide detailed insight into the fuel injection process at actual conditions, thereby greatly enhancing the evaluation of fuel injector performance and other combustion phenomena. Stable species such as CO2, O2, N2, H2O, and hydrocarbons are also investigated by a newly demonstrated 1-D, spontaneous Raman spectroscopic method. This visible wavelength Raman technique allows the acquisition of quantitative, stable species concentration measurements from the flow.
Evaluation of N,N-dialkylamides as promising process extractants
NASA Astrophysics Data System (ADS)
Pathak, P. N.; Prabhu, D. R.; Kanekar, A. S.; Manchanda, V. K.
2010-03-01
Studies carried out at BARC, India on the development of new extractants for reprocessing of spent fuel suggested that while straight chain N,N-dihexyloctanamide (DHOA) is promising alternative to TBP for the reprocessing of irradiated uranium based fuels, branched chain N,N-di(2-ethylhexyl)isobutyramide (D2EHIBA) is suitable for the selective recovery of 233U from irradiated Th. In advanced fuel cycle scenarios, the coprocessing of U/Pu stream appears attractive particularly with respect to development of proliferation resistant technologies. DHOA extracted Pu(IV) more efficiently than TBP, both at trace-level concentration as well as under uranium/plutonium loading conditions. Uranium extraction behavior of DHOA was however, similar to that of TBP during the extraction cycle. Stripping behavior of U and Pu (without any reductant) was better for DHOA than that of TBP. It was observed during batch studies that whereas 99% Pu is stripped in four stages in case of DHOA, only 89% Pu is stripped in case of TBP under identical experimental conditions. DHOA offered better fission product decontamination than that of TBP. GANEX (Group ActiNide EXtraction) and ARTIST (Amide-based Radio-resources Treatment with Interim Storage of Transuranics) processes proposed for actinide partitioning use branched chain amides for the selective extraction of uranium from spent fuel feed solutions. The branched-alkyl monoamide (BAMA) proposed to be used in ARTIST process is N,N-di-(2-ethylhexyl)butyramide (D2EHBA). In this context, the extraction behavior of U(VI) and Pu(IV) were compared using D2EHIBA, TBP, and D2EHBA under similar concentration of nitric acid (0.5 — 6M) and of uranium (0-50g/L). These studies suggested that D2EHIBA is a promising extractant for selective extraction of uranium over plutonium in process streams. Similarly, D2EHIBA offered distinctly better decontamination of 233U over Th and fission products under THOREX feed conditions. The possibility of simultaneous stripping and precipitation of thorium (as oxalate) from loaded organic phase was explored using 0.05M oxalic acid. Ammonium diuranate (ADU) precipitation was performed on the oxalate supernatant for the recovery of uranium. Quantitative recovery (>99.9%) of Th as well as of U was achieved. Radiolytic studies suggested that irradiated DHOA and D2EHIBA behaved better with respect to fission product decontamination as compared to that of TBP.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Indacochea, J. E.; Gattu, V. K.; Chen, X.
The results of electrochemical corrosion tests and modeling activities performed collaboratively by researchers at the University of Illinois at Chicago and Argonne National Laboratory as part of workpackage NU-13-IL-UIC-0203-02 are summarized herein. The overall objective of the project was to develop and demonstrate testing and modeling approaches that could be used to evaluate the use of composite alloy/ceramic materials as high-level durable waste forms. Several prototypical composite waste form materials were made from stainless steels representing fuel cladding, reagent metals representing metallic fuel waste streams, and reagent oxides representing oxide fuel waste streams to study the microstructures and corrosion behaviorsmore » of the oxide and alloy phases. Microelectrodes fabricated from small specimens of the composite materials were used in a series of electrochemical tests to assess the corrosion behaviors of the constituent phases and phase boundaries in an aggressive acid brine solution at various imposed surface potentials. The microstructures were characterized in detail before and after the electrochemical tests to relate the electrochemical responses to changes in both the electrode surface and the solution composition. The results of microscopic, electrochemical, and solution analyses were used to develop equivalent circuit and physical models representing the measured corrosion behaviors of the different materials pertinent to long-term corrosion behavior. This report provides details regarding (1) the production of the composite materials, (2) the protocol for the electrochemical measurements and interpretations of the responses of multi-phase alloy and oxide composites, (3) relating corrosion behaviors to microstructures of multi-phase alloys based on 316L stainless steel and HT9 (410 stainless steel was used as a substitute) with added Mo, Ni, and/or Mn, and (4) modeling the corrosion behaviors and rates of several alloy/oxide composite materials made with added lanthanide and uranium oxides. These analyses show the corrosion behaviors of the alloy/ceramic composite materials are very similar to the corrosion behaviors of multi-phase alloy waste forms, and that the presence of oxide inclusions does not impact the corrosion behaviors of the alloy phases. Mixing with metallic waste streams is beneficial to lanthanide and uranium oxides in that they react with Zr in the fuel waste to form highly durable zirconates. The measured corrosion behaviors suggest properly formulated composite materials would be suitable waste forms for combined metallic and oxide waste streams generated during electrometallurgical reprocessing of spent nuclear fuel. Electrochemical methods are suitable for evaluating the durability and modeling long-term behavior of composite waste forms: the degradation model developed for metallic waste forms can be applied to the alloy phases formed in the composite and an affinity-based mineral dissolution model can be applied to the ceramic phases.« less
Flame blowout and pollutant emissions in vitiated combustion of conventional and bio-derived fuels
NASA Astrophysics Data System (ADS)
Singh, Bhupinder
The widening gap between the demand and supply of fossil fuels has catalyzed the exploration of alternative sources of energy. Interest in the power, water extraction and refrigeration (PoWER) cycle, proposed by the University of Florida, as well as the desirability of using biofuels in distributed generation systems, has motivated the exploration of biofuel vitiated combustion. The PoWER cycle is a novel engine cycle concept that utilizes vitiation of the air stream with externally-cooled recirculated exhaust gases at an intermediate pressure in a semi-closed cycle (SCC) loop, lowering the overall temperature of combustion. It has several advantages including fuel flexibility, reduced air flow, lower flame temperature, compactness, high efficiency at full and part load, and low emissions. Since the core engine air stream is vitiated with the externally cooled exhaust gas recirculation (EGR) stream, there is an inherent reduction in the combustion stability for a PoWER engine. The effect of EGR flow and temperature on combustion blowout stability and emissions during vitiated biofuel combustion has been characterized. The vitiated combustion performance of biofuels methyl butanoate, dimethyl ether, and ethanol have been compared with n-heptane, and varying compositions of syngas with methane fuel. In addition, at high levels of EGR a sharp reduction in the flame luminosity has been observed in our experimental tests, indicating the onset of flameless combustion. This drop in luminosity may be a result of inhibition of processes leading to the formation of radiative soot particles. One of the objectives of this study is finding the effect of EGR on soot formation, with the ultimate objective of being able to predict the boundaries of flameless combustion. Detailed chemical kinetic simulations were performed using a constant-pressure continuously stirred tank reactor (CSTR) network model developed using the Cantera combustion code, implemented in C++. Results have been presented showing comparative trends in pollutant emissions generation, flame blowout stability, and combustion efficiency. (Full text of this dissertation may be available via the University of Florida Libraries web site. Please check http://www.uflib.ufl.edu/etd.html)
Fuel-Flexible Gasification-Combustion Technology for Production of H2 and Sequestration-Ready CO2
DOE Office of Scientific and Technical Information (OSTI.GOV)
George Rizeq; Parag Kulkarni; Wei Wei
It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Global Research is developing an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GE was awarded a contract frommore » U.S. DOE NETL to develop the UFP technology. Work on the Phase I program started in October 2000, and work on the Phase II effort started in April 2005. In the UFP technology, coal and air are simultaneously converted into separate streams of (1) high-purity hydrogen that can be utilized in fuel cells or turbines, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure vitiated air to produce electricity in a gas turbine. The process produces near-zero emissions with an estimated efficiency higher than IGCC with conventional CO2 separation. The Phase I R&D program established the feasibility of the integrated UFP technology through lab-, bench- and pilot-scale testing and investigated operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The Phase I effort integrated experimental testing, modeling and preliminary economic studies to demonstrate the UFP technology. The Phase II effort will focus on three high-risk areas: economics, sorbent attrition and lifetime, and product gas quality for turbines. The economic analysis will include estimating the capital cost as well as the costs of hydrogen and electricity for a full-scale UFP plant. These costs will be benchmarked with IGCC polygen costs for plants of similar size. Sorbent attrition and lifetime will be addressed via bench-scale experiments that monitor sorbent performance over time and by assessing materials interactions at operating conditions. The product gas from the third reactor (high-temperature vitiated air) will be evaluated to assess the concentration of particulates, pollutants and other impurities relative to the specifications required for gas turbine feed streams. This is the eighteenth quarterly technical progress report for the UFP program, which is supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974) and GE. This report summarizes program accomplishments for the Phase II period starting July 01, 2005 and ending September 30, 2005. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including process modeling, scale-up and economic analysis.« less
Strategic Minimization of High Level Waste from Pyroprocessing of Spent Nuclear Fuel
DOE Office of Scientific and Technical Information (OSTI.GOV)
Simpson, Michael F.; Benedict, Robert W.
The pyroprocessing of spent nuclear fuel results in two high-level waste streams--ceramic and metal waste. Ceramic waste contains active metal fission product-loaded salt from the electrorefining, while the metal waste contains cladding hulls and undissolved noble metals. While pyroprocessing was successfully demonstrated for treatment of spent fuel from Experimental Breeder Reactor-II in 1999, it was done so without a specific objective to minimize high-level waste generation. The ceramic waste process uses “throw-away” technology that is not optimized with respect to volume of waste generated. In looking past treatment of EBR-II fuel, it is critical to minimize waste generation for technologymore » developed under the Global Nuclear Energy Partnership (GNEP). While the metal waste cannot be readily reduced, there are viable routes towards minimizing the ceramic waste. Fission products that generate high amounts of heat, such as Cs and Sr, can be separated from other active metal fission products and placed into short-term, shallow disposal. The remaining active metal fission products can be concentrated into the ceramic waste form using an ion exchange process. It has been estimated that ion exchange can reduce ceramic high-level waste quantities by as much as a factor of 3 relative to throw-away technology.« less
Apparatus and method for controlling the secondary injection of fuel
Martin, Scott M.; Cai, Weidong; Harris, Jr., Arthur J.
2013-03-05
A combustor (28) for a gas turbine engine is provided comprising a primary combustion chamber (30) for combusting a first fuel to form a combustion flow stream (50) and a transition piece (32) located downstream from the primary combustion chamber (30). The transition piece (32) comprises a plurality of injectors (66) located around a circumference of the transition piece (32) for injecting a second fuel into the combustion flow stream (50). The injectors (66) are effective to create a radial temperature profile (74) at an exit (58) of the transition piece (32) having a reduced coefficient of variation relative to a radial temperature profile (64) at an inlet (54) of the transition piece (32). Methods for controlling the temperature profile of a secondary injection are also provided.
2014-01-01
Summary The advantages of liquid fuel cells (LFCs) over conventional hydrogen–oxygen fuel cells include a higher theoretical energy density and efficiency, a more convenient handling of the streams, and enhanced safety. This review focuses on the use of different types of organic fuels as an anode material for LFCs. An overview of the current state of the art and recent trends in the development of LFC and the challenges of their practical implementation are presented. PMID:25247123
Groundwater contaminants in the deep benthic zone of urban streams in Canada (Invited)
NASA Astrophysics Data System (ADS)
Roy, J. W.; Bickerton, G.
2010-12-01
There is little information available on the potential threat that groundwater containing land-based contaminants poses to aquatic ecosystems in urban environments. In this study, a rapid screening approach was applied at the stream reach-scale for eight urban streams (reaches from 100 to < 1000 m). The objective was to determine what types of groundwater contaminants could be detected in the deeper benthic zone of these streams, if any, to start to address questions of whether such contaminants are a concern and which types are the most problematic. The benthic community may be especially at risk since it may experience higher contaminant concentrations than the stream itself due to fewer losses from sorption, degradation and volatilization processes. For each stream, groundwater samples from below the stream bed (typically 25-75 cm) were collected using a drive-point mini-profiler at intervals of 10-15 m along the stream and were subsequently analysed for general chemistry and a wide range of common and emerging urban contaminants. For a few test streams with known contamination, the area of contamination was identified with this technique. In addition, previously unknown contaminants or areas of contamination were identified at all nine streams. Identified contaminants included benzene and other petroleum hydrocarbons, fuel oxygenates (e.g. MTBE), perchlorate, pesticides, artificial sweeteners, and various chlorinated solvent compounds. In addition, elevated levels of nitrate, phosphate, some heavy metals, including cadmium and arsenic, and elevated chloride (likely indicating road salt) were detected. Most streams had many different types of contaminants, often overlapping over small stretches, and together often covering substantial portions of the monitored reach. The findings provide support for this screening approach for delineating areas of potential ecological concern and identifying possible sources of groundwater contamination, for urban settings. They also suggest that the presence of multiple groundwater contaminants may be a more common threat to the benthic community of urban streams than currently perceived.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nan, Yue; Tavlarides, Lawrence L.; DePaoli, David W.
The adsorption process of iodine, a major volatile radionuclide in the off-gas streams of spent nuclear fuel reprocessing, on hydrogen-reduced silver-exchanged mordenite (Ag 0Z) was studied at the micro-scale. The gas-solid mass transfer and reaction involved in the adsorption process were investigated and evaluated with appropriate models. Optimal conditions for reducing the silver-exchanged mordenite (AgZ) in a hydrogen stream were determined. Kinetic and equilibrium data of iodine adsorption on Ag 0Z were obtained by performing single-layer adsorption experiments with experimental systems of high precision at 373–473 K over various iodine concentrations. Results indicate approximately 91% to 97% of the iodinemore » adsorption was through the silver-iodine reaction. The effect of temperature on the iodine loading capacity of Ag 0Z was discussed. In conclusion, the Shrinking Core model describes the data well, and the primary rate controlling mechanisms were macro-pore diffusion and silver-iodine reaction. © 2016 American Institute of Chemical Engineers AIChE J, 2016« less
Sathish, Ashik; Marlar, Tyler; Sims, Ronald C
2015-10-01
Methods to convert microalgal biomass to bio based fuels and chemicals are limited by several processing and economic hurdles. Research conducted in this study modified/optimized a previously published procedure capable of extracting transesterifiable lipids from wet algal biomass. This optimization resulted in the extraction of 77% of the total transesterifiable lipids, while reducing the amount of materials and temperature required in the procedure. In addition, characterization of side streams generated demonstrated that: (1) the C/N ratio of the residual biomass or lipid extracted (LE) biomass increased to 54.6 versus 10.1 for the original biomass, (2) the aqueous phase generated contains nitrogen, phosphorous, and carbon, and (3) the solid precipitate phase was composed of up to 11.2 wt% nitrogen (70% protein). The ability to isolate algal lipids and the possibility of utilizing generated side streams as products and/or feedstock material for downstream processes helps promote the algal biorefinery concept. Copyright © 2015 Elsevier Ltd. All rights reserved.
Apparatus and method of controlling the thermal performance of an oxygen-fired boiler
Levasseur, Armand A.; Kang, Shin G.; Kenney, James R.; Edberg, Carl D.
2017-09-05
Disclosed herein is a method of controlling the operation of an oxy-fired boiler; the method comprising combusting a fuel in a boiler; producing a heat absorption pattern in the boiler; discharging flue gases from the boiler; recycling a portion of the flue gases to the boiler; combining a first oxidant stream with the recycled flue gases to form a combined stream; splitting the combined stream into several fractions; and introducing each fraction of the combined stream to the boiler at different points of entry to the boiler.
Manzoor Bhat, Zahid; Thimmappa, Ravikumar; Devendrachari, Mruthyunjayachari Chattanahalli; Kottaichamy, Alagar Raja; Shafi, Shahid Pottachola; Varhade, Swapnil; Gautam, Manu; Thotiyl, Musthafa Ottakam
2018-01-18
State-of-the-art proton exchange membrane fuel cells (PEMFCs) anodically inhale H 2 fuel and cathodically expel water molecules. We show an unprecedented fuel cell concept exhibiting cathodic fuel exhalation capability of anodically inhaled fuel, driven by the neutralization energy on decoupling the direct acid-base chemistry. The fuel exhaling fuel cell delivered a peak power density of 70 mW/cm 2 at a peak current density of 160 mA/cm 2 with a cathodic H 2 output of ∼80 mL in 1 h. We illustrate that the energy benefits from the same fuel stream can at least be doubled by directing it through proposed neutralization electrochemical cell prior to PEMFC in a tandem configuration.
Experimental study on air-stream gasification of biomass micron fuel (BMF) in a cyclone gasifier.
Guo, X J; Xiao, B; Zhang, X L; Luo, S Y; He, M Y
2009-01-01
Based on biomass micron fuel (BMF) with particle size of less than 250 microm, a cyclone gasifier concept has been considered in our laboratory for biomass gasification. The concept combines and integrates partial oxidation, fast pyrolysis, gasification, and tar cracking, as well as a shift reaction, with the purpose of producing a high quality of gas. In this paper, experiments of BMF air-stream gasification were carried out by the gasifier, with energy for BMF gasification produced by partial combustion of BMF within the gasifier using a hypostoichiometric amount of air. The effects of ER (0.22-0.37) and S/B (0.15-0.59) and biomass particle size on the performances of BMF gasification and the gasification temperature were studied. Under the experimental conditions, the temperature, gas yields, LHV of the gas fuel, carbon conversion efficiency, stream decomposition and gasification efficiency varied in the range of 586-845 degrees C, 1.42-2.21 N m(3)/kg biomass, 3806-4921 kJ/m(3), 54.44%-85.45%, 37.98%-70.72%, and 36.35%-56.55%, respectively. The experimental results showed that the gasification performance was best with ER being 3.7 and S/B being 0.31 and smaller particle, as well as H(2)-content. And the BMF gasification by air and low temperature stream in the cyclone gasifier with the energy self-sufficiency is reliable.
Prioritized List of Research Needs to support MRWFD Case Study Flowsheet Advancement
DOE Office of Scientific and Technical Information (OSTI.GOV)
Law, Jack Douglas; Soelberg, Nicholas Ray
In FY-13, a case study evaluation was performed of full recycle technologies for both the processing of light-water reactor (LWR) used nuclear fuels as well as fast reactor (FR) fuel in the full recycle option. This effort focused on the identification of the case study processes and the initial preparation of material balance flowsheets for the identified technologies. In identifying the case study flowsheets, it was decided that two cases would be developed: one which identifies the flowsheet as currently developed and another near-term target flowsheet which identifies the flowsheet as envisioned within two years, pending the results of ongoingmore » research. The case study focus is on homogeneous aqueous recycle of the U/TRU resulting from the processing of LWR fuel as feed for metal fuel fabrication. The metal fuel is utilized in a sodium-cooled fast reactor, and the used fast reactor fuel is processed using electrochemical separations. The recovered U/TRU from electrochemical separations is recycled to fuel fabrication and the fast reactor. Waste streams from the aqueous and electrochemical processing are treated and prepared for disposition. Off-gas from the separations and waste processing are also treated. As part of the FY-13 effort, preliminary process unknowns and research needs to advance the near-term target flowsheets were identified. In FY-14, these research needs were updated, expanded and prioritized. This report again updates the prioritized list of research needs based upon results to date in FY-15. The research needs are listed for each of the main portions of the flowsheet: 1) Aqueous headend, 2) Headend tritium pretreatment off-gas, 3) Aqueous U/Pu/Np recovery, 4) Aqueous TRU product solidification, 5) Aqueous actinide/lanthanide separation, 6) Aqueous off-gas treatment, 7) Aqueous HLW management, 8) Treatment of aqueous process wastes, 9) E-chem actinide separations, 10) E-chem off-gas, 11) E-chem HLW management. The identified research needs were prioritized within each of these areas. No effort was made to perform an overall prioritization. This information will be used by the MRWFD Campaign leadership in research planning for FY-16. Additionally, this information will be incorporated into the next version of the Case Study Report scheduled to be issued September 2015.« less
NASA Astrophysics Data System (ADS)
Simson, Amanda
Hydrogen powered fuel cells have the potential to produce electricity with higher efficiency and lower emissions than conventional combustion technology. In order to realize the benefits of a hydrogen fuel cell an efficient method to produce hydrogen is needed. Currently, over 90% of hydrogen is produced from the steam reforming of natural gas. However, for many applications including fuel cell vehicles, the use of a liquid fuel rather than natural gas is desirable. This work investigates the feasibility of producing hydrogen efficiently by steam reforming E85 (85% ethanol/15% gasoline), a commercially available sulfur-containing transportation fuel. A Rh-Pt/SiO2-ZrO2 catalyst has demonstrated good activity for the E85 steam reforming reaction. An industrial steam reforming process is often run less efficiently, with more water and at higher temperatures, in order to prevent catalyst deactivation. Therefore, it is desirable to develop a process that can operate without catalyst deactivation at more energy efficient conditions. In this study, the steam reforming of a sulfur-containing fuel (E85) was studied at near stoichiometric steam/carbon ratios and at 650C, conditions at which catalyst deactivation is normally measured. At these conditions the catalyst was found to be stable steam reforming a sulfur-free E85. However, the addition of low concentrations of sulfur significantly deactivated the catalyst. The presence of sulfur in the fuel caused catalyst deactivation by promoting ethylene which generates surface carbon species (coke) that mask catalytic sites. The amount of coke increased during time on stream and became increasingly graphitic. However, the deactivation due to both sulfur adsorption and coke formation was reversible with air treatment at 650°C. However, regenerations were found to reduce the catalyst life. Air regenerations produce exotherms on the catalyst surface that cause structural changes to the catalyst. During regenerations the accessibility of the precious metal particles is reduced which causes the catalyst to deactivate more rapidly during subsequent steam reforming cycles. Changes to the carrier morphology also occur at these conditions. Regenerating the catalyst before significant deactivation is measured can improve the stability of the catalyst. Thus a process with preemptive controlled air regenerations is proposed in order to run a steam reforming process with sulfur containing fuels.
The Impact of Low Octane Hydrocarbon Blending Streams on Ethanol Engine Optimization
DOE Office of Scientific and Technical Information (OSTI.GOV)
Szybist, James P; West, Brian H
2013-01-01
Ethanol is a very attractive fuel from an end-use perspective because it has a high chemical octane number and a high latent heat of vaporization. When an engine is optimized to take advantage of these fuel properties, both efficiency and power can be increased through higher compression ratio, direct fuel injection, higher levels of boost, and a reduced need for enrichment to mitigate knock or protect the engine and aftertreatment system from overheating. The ASTM D5798 specification for high level ethanol blends, commonly called E85, underwent a major revision in 2011. The minimum ethanol content was revised downward from 68more » vol% to 51 vol%, which combined with the use of low octane blending streams such as natural gasoline introduces the possibility of a lower octane E85 fuel. While this fuel is suitable for current ethanol tolerant flex fuel vehicles, this study experimentally examines whether engines can still be aggressively optimized for the resultant fuel from the revised ASTM D5798 specification. The performance of six ethanol fuel blends, ranging from 51-85% ethanol, is compared to a premium-grade certification gasoline (UTG-96) in a single-cylinder direct-injection (DI) engine with a compression ratio of 12.9:1 at knock-prone engine conditions. UTG-96 (RON = 96.1), light straight run gasoline (RON = 63.6), and n-heptane (RON = 0) are used as the hydrocarbon blending streams for the ethanol-containing fuels in an effort to establish a broad range of knock resistance for high ethanol fuels. Results show that nearly all ethanol-containing fuels are more resistant to engine knock than UTG-96 (the only exception being the ethanol blend with 49% n-heptane). This knock resistance allows ethanol blends made with 33 and 49% light straight run gasoline, and 33% n-heptane to be operated at significantly more advanced combustion phasing for higher efficiency, as well as at higher engine loads. While experimental results show that the octane number of the hydrocarbon blend stock does impact engine performance, there remains a significant opportunity for engine optimization when considering even the lowest octane fuels that are in compliance with the current revision of ASTM D5798 compared to premium-grade gasoline.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, W.; Mittal, A.; Mohagheghi, A.
PHAs are synthesized by many microorganisms to serve as intracellular carbon storage molecules. In some bacterial strains, PHB can account for up to 80% of cell mass. In addition to its application in the packaging sector, PHB also has great potential as an intermediate in the production of hydrocarbon fuels. PHB can be thermally depolymerized and decarboxylated to propene which can be upgraded to hydrocarbon fuels via commercial oligomerization technologies. Cupriavidus necator is the microorganism that has been most extensively studied and used for PHB production on an industrial scale; However the substrates used for producing PHB are mainly fructose,more » glucose, sucrose, fatty acids, glycerol, etc., which are expensive. In this study, we demonstrate production of PHB from a process relevant lignocellulosic derived sugar stream, i.e., saccharified slurry from pretreated corn stover. The strain was first investigated in shake flasks for its ability to utilize glucose, xylose and acetate. In addition, the strain was also grown on pretreated lignocellulose hydrolyzate slurry and evaluated in terms of cell growth, sugar utilization, PHB accumulation, etc. The mechanism of inhibition in the toxic hydrolysate generated by the pretreatment and saccharification process of biomass, was also studied.« less
Increasing Operational Stability in Low NO
NASA Astrophysics Data System (ADS)
Levy, Yeshayahou; Erenburg, Vladimir; Sherbaum, Valery; Ovcharenko, Vitali; Rosentsvit, Leonid; Chudnovsky, Boris; Herszage, Amiel; Talanker, Alexander
2012-03-01
Lean combustion is a method in which combustion takes place under low equivalence ratio and relatively low combustion temperatures. As such, it has the potential to lower the effect of the relatively high activation energy nitrogen-oxygen reactions which are responsible for substantial NO
Combustion chamber and thermal vapor stream producing apparatus and method
Sperry, John S.; Krajicek, Richard W.; Cradeur, Robert R.
1978-01-01
A new and improved method and apparatus for burning a hydrocarbon fuel for producing a high pressure thermal vapor stream comprising steam and combustion gases for injecting into a subterranean formation for the recovery of liquefiable minerals therefrom, wherein a high pressure combustion chamber having multiple refractory lined combustion zones of varying diameters is provided for burning a hydrocarbon fuel and pressurized air in predetermined ratios injected into the chamber for producing hot combustion gases essentially free of oxidizing components and solid carbonaceous particles. The combustion zones are formed by zones of increasing diameters up a final zone of decreasing diameter to provide expansion zones which cause turbulence through controlled thorough mixing of the air and fuel to facilitate complete combustion. The high pressure air and fuel is injected into the first of the multiple zones where ignition occurs with a portion of the air injected at or near the point of ignition to further provide turbulence and more complete combustion.
Evaluation of Impinging Stream Vortex Chamber Concepts for Liquid Rocket Engine Applications
NASA Technical Reports Server (NTRS)
Trinh, Huu P.; Bullard, Brad; Kopicz, Charles; Michaels, Scott; Turner, James (Technical Monitor)
2001-01-01
To pursue technology developments for future launch vehicles, NASA/Marshall Space Flight Center (MSFC) is examining vortex chamber concepts for liquid rocket engine applications. Past studies indicated that the vortex chamber schemes potentially have a number of advantages over conventional chamber methods. Due to the nature of the vortex flow, relatively cooler propellant streams tend to flow along the chamber wall. Hence, the thruster chamber can be operated without the need of any cooling techniques. This vortex flow also creates strong turbulence, which promotes the propellant mixing process. Consequently, the subject chamber concepts not only offer the system simplicity, but they also would enhance the combustion performance. The test results showed that the chamber performance was markedly high even at a low chamber length-to-diameter ratio (L/D). This incentive can be translated to a convenience in the thrust chamber packaging. Variations of the vortex chamber concepts have been introduced in the past few decades. These investigations include an ongoing work at Orbital Technologies Corporation (ORBITEC). By injecting the oxidizer tangentially at the chamber convergence and fuel axially at the chamber head end, Knuth et al. were able to keep the wall relatively cold. A recent investigation of the low L/D vortex chamber concept for gel propellants was conducted by Michaels. He used both triplet (two oxidizer and one fuel orifices) and unlike impinging schemes to inject propellants tangentially along the chamber wall. Michaels called the subject injection scheme as Impinging Stream Vortex Chamber (ISVC). His preliminary tests showed that high performance, with an Isp efficiency of 92%, can be obtained. MSFC and the U.S. Army are jointly investigating an application of the ISVC concept for the cryogenic oxygen/hydrocarbon propellant system. This vortex chamber concept is currently tested with gel propellants at AMCOM at Redstone Arsenal, Alabama. A version of this concept for the liquid oxygen (LOX)/hydrocarbon fuel (RPM) system has been derived from the one for the gel propellant.
An economical route to high quality lubricants
DOE Office of Scientific and Technical Information (OSTI.GOV)
Andre, J.P.; Hahn, S.K.; Kwon, S.H.
1996-12-01
The current rends in the automotive and industrial markets toward more efficient engines, longer drain intervals, and lower emissions all contribute to placing increasingly stringent performance requirements on lubricants. The demand for higher quality synthetic and non-conventional basestocks is expected to grow at a much faster rate than that of conventional lube basestocks to meet these higher performance standards. Yukong Limited has developed a novel technology (the Yukong UCO Lube Process) for the economic production of high quality, high-viscosity-index lube basestocks from a fuels hydrocracker unconverted oil stream. A pilot plant based on this process has been producing oils formore » testing purposes since May 1994. A commercial facility designed to produce 3,500 BPD of VHVI lube basestocks cane on-stream at Yukong`s Ulsan refinery in October 1995. The Badger Technology Center of Raytheon Engineers and Constructors assisted Yukong during the development of the technology and prepared the basic process design package for the commercial facility. This paper presents process aspects of the technology and comparative data on investment and operating costs. Yukong lube basestock product properties and performance data are compared to basestocks produced by conventional means and by lube hydrocracking.« less
High Angular Momentum Halo Gas: A Feedback and Code-independent Prediction of LCDM
NASA Astrophysics Data System (ADS)
Stewart, Kyle R.; Maller, Ariyeh H.; Oñorbe, Jose; Bullock, James S.; Joung, M. Ryan; Devriendt, Julien; Ceverino, Daniel; Kereš, Dušan; Hopkins, Philip F.; Faucher-Giguère, Claude-André
2017-07-01
We investigate angular momentum acquisition in Milky Way-sized galaxies by comparing five high resolution zoom-in simulations, each implementing identical cosmological initial conditions but utilizing different hydrodynamic codes: Enzo, Art, Ramses, Arepo, and Gizmo-PSPH. Each code implements a distinct set of feedback and star formation prescriptions. We find that while many galaxy and halo properties vary between the different codes (and feedback prescriptions), there is qualitative agreement on the process of angular momentum acquisition in the galaxy’s halo. In all simulations, cold filamentary gas accretion to the halo results in ˜4 times more specific angular momentum in cold halo gas (λ cold ≳ 0.1) than in the dark matter halo. At z > 1, this inflow takes the form of inspiraling cold streams that are co-directional in the halo of the galaxy and are fueled, aligned, and kinematically connected to filamentary gas infall along the cosmic web. Due to the qualitative agreement among disparate simulations, we conclude that the buildup of high angular momentum halo gas and the presence of these inspiraling cold streams are robust predictions of Lambda Cold Dark Matter galaxy formation, though the detailed morphology of these streams is significantly less certain. A growing body of observational evidence suggests that this process is borne out in the real universe.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Muraleedharan, T.R.; Venkobachar, C.; Leela, I.
1994-09-01
The revival of interest in biotechnology has fueled research in many sectors of environmental biotechnology. The present paper describes research utilizing adsorbents prepared from wood-rotting mushrooms growing wild in tropical forests. Nine species of mushrooms were screened using copper(II) as the model adsorbate. While may species showed excellent potential, comparable to biosorbents reported in literature, Ganodernma lucidum emerged as the best biosorbent. This biosorbent was further developed for use in a packed-bed bioreactor for treatment of rare earth processing effluents. Electron paramagnetic studies confirmed that adsorption is by chemical binding to the biosorbent.
Hydrogen production from carbonaceous material
Lackner, Klaus S.; Ziock, Hans J.; Harrison, Douglas P.
2004-09-14
Hydrogen is produced from solid or liquid carbon-containing fuels in a two-step process. The fuel is gasified with hydrogen in a hydrogenation reaction to produce a methane-rich gaseous reaction product, which is then reacted with water and calcium oxide in a hydrogen production and carbonation reaction to produce hydrogen and calcium carbonate. The calcium carbonate may be continuously removed from the hydrogen production and carbonation reaction zone and calcined to regenerate calcium oxide, which may be reintroduced into the hydrogen production and carbonation reaction zone. Hydrogen produced in the hydrogen production and carbonation reaction is more than sufficient both to provide the energy necessary for the calcination reaction and also to sustain the hydrogenation of the coal in the gasification reaction. The excess hydrogen is available for energy production or other purposes. Substantially all of the carbon introduced as fuel ultimately emerges from the invention process in a stream of substantially pure carbon dioxide. The water necessary for the hydrogen production and carbonation reaction may be introduced into both the gasification and hydrogen production and carbonation reactions, and allocated so as transfer the exothermic heat of reaction of the gasification reaction to the endothermic hydrogen production and carbonation reaction.
Auxiliary reactor for a hydrocarbon reforming system
Clawson, Lawrence G.; Dorson, Matthew H.; Mitchell, William L.; Nowicki, Brian J.; Bentley, Jeffrey M.; Davis, Robert; Rumsey, Jennifer W.
2006-01-17
An auxiliary reactor for use with a reformer reactor having at least one reaction zone, and including a burner for burning fuel and creating a heated auxiliary reactor gas stream, and heat exchanger for transferring heat from auxiliary reactor gas stream and heat transfer medium, preferably two-phase water, to reformer reaction zone. Auxiliary reactor may include first cylindrical wall defining a chamber for burning fuel and creating a heated auxiliary reactor gas stream, the chamber having an inlet end, an outlet end, a second cylindrical wall surrounding first wall and a second annular chamber there between. The reactor being configured so heated auxiliary reactor gas flows out the outlet end and into and through second annular chamber and conduit which is disposed in second annular chamber, the conduit adapted to carry heat transfer medium and being connectable to reformer reaction zone for additional heat exchange.
NASA Technical Reports Server (NTRS)
Ferkul, Paul V.
1989-01-01
The flame spread and flame extinction characteristics of a thin fuel burning in a low-speed forced convective environment in microgravity were examined. The flame spread rate was observed to decrease both with decreasing ambient oxygen concentration as well as decreasing free stream velocity. A new mode of flame extinction was observed, caused by either of two means: keeping the free stream velocity constant and decreasing the oxygen concentration, or keeping the oxygen concentration constant and decreasing the free stream velocity. This extinction is called quenching extinction. By combining this data together with a previous microgravity quiescent flame study and normal-gravity blowoff extinction data, a flammability map was constructed with molar percentage oxygen and characteristic relative velocity as coordinates. The Damkohler number is not sufficient to predict flame spread and extinction in the near quench limit region.
Variable cycle engines for advanced supersonic transports
NASA Technical Reports Server (NTRS)
Howlett, R. A.; Kozlowski, H.
1975-01-01
Variable Cycle Engines being studied for advanced commercial supersonic transports show potential for significant environmental and economic improvements relative to 1st generation SST engines. The two most promising concepts are: a Variable Stream Control Engine and a Variable Cycle Engine with a rear flow-control valve. Each concept utilizes variable components and separate burners to provide independent temperature and velocity control for two coannular flow streams. Unique fuel control techniques are combined with cycle characteristics that provide low fuel consumption, similar to a turbojet engine, for supersonic operation. This is accomplished while retaining the good subsonic performance features of a turbofan engine. A two-stream coannular nozzle shows potential to reduce jet noise to below FAR Part 36 without suppressors. Advanced burner concepts have the potential for significant reductions in exhaust emissions. In total, these unique engine concepts have the potential for significant overall improvements to the environmental and economic characteristics of advanced supersonic transports.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kearney, M; Kochergin, V; Hess, R
2005-03-31
Large-scale displacement of petroleum will come from low-cost cellulosic feedstocks such as straw and corn stover crop residues. This project has taken a step toward making this projection a reality by reducing capital and energy costs, the two largest cost factors associated with converting cellulosic biomass to chemicals and fuels. The technology exists for using acid or enzyme hydrolysis processes to convert biomass feedstock (i.e., waste cellulose such as straw, corn stover, and wood) into their base monomeric sugar building blocks, which can, in turn, be processed into chemicals and fuels using a number of innovative fermentation technologies. However, whilemore » these processes are technically possible, practical and economic barriers make these processes only marginally feasible or not feasible at all. These barriers are due in part to the complexity and large fixed and recurring capital costs of unit operations including filtration, chromatographic separation, and ion exchange. This project was designed to help remove these barriers by developing and implementing new purification and separation technologies that will reduce the capital costs of the purification and chromatographic separation units by 50% to 70%. The technologies fundamental to these improvements are: (a) highly efficient clarification and purification systems that use screening and membrane filtration to eliminate suspended solids and colloidal material from feed streams and (b) fractal technology based chromatographic separation and ion exchange systems that can substitute for conventional systems but at much smaller size and cost. A non-hazardous ''raw sugar beet juice'' stream (75 to 100 gal/min) was used for prototype testing of these technologies. This raw beet juice stream from the Amalgamated Sugar LLC plant in Twin Falls, Idaho contained abrasive materials and membrane foulants. Its characteristics were representative of an industrial-scale heterogeneous plant extract/hydrolysis stream, and therefore was an ideal model system for developing new separation equipment. Subsequent testing used both synthetic acid hydrolysate and corn stover derived weak acid hydrolysate (NREL produced). A two-phased approach was used for the research and development described in this project. The first level of study involved testing the new concepts at the bench level. The bench-scale evaluations provided fundamental understanding of the processes, building and testing small prototype systems, and determining the efficiency of the novel processes. The second level of study, macro-level, required building larger systems that directly simulated industrial operations and provided validation of performance to minimize financial risk during commercialization. The project goals and scope included: (1) Development of low-capital alternatives to conventional crop-based purification/separation processes; and (2) Development of each process to the point that transition to commercial operation is low risk. The project reporting period was January 2001 to December 2004. This included a one year extension of the project (without additional funding).« less
Recovery Act: Novel Oxygen Carriers for Coal-fueled Chemical Looping
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pan, Wei-Ping; Cao, Yan
2012-11-30
Chemical Looping Combustion (CLC) could totally negate the necessity of pure oxygen by using oxygen carriers for purification of CO{sub 2} stream during combustion. It splits the single fuel combustion reaction into two linked reactions using oxygen carriers. The two linked reactions are the oxidation of oxygen carriers in the air reactor using air, and the reduction of oxygen carriers in the fuel reactor using fuels (i.e. coal). Generally metal/metal oxides are used as oxygen carriers and operated in a cyclic mode. Chemical looping combustion significantly improves the energy conversion efficiency, in terms of the electricity generation, because it improvesmore » the reversibility of the fuel combustion process through two linked parallel processes, compared to the conventional combustion process, which is operated far away from its thermo-equilibrium. Under the current carbon-constraint environment, it has been a promising carbon capture technology in terms of fuel combustion for power generation. Its disadvantage is that it is less mature in terms of technological commercialization. In this DOE-funded project, accomplishment is made by developing a series of advanced copper-based oxygen carriers, with properties of the higher oxygen-transfer capability, a favorable thermodynamics to generate high purity of CO{sub 2}, the higher reactivity, the attrition-resistance, the thermal stability in red-ox cycles and the achievement of the auto-thermal heat balance. This will be achieved into three phases in three consecutive years. The selected oxygen carriers with final-determined formula were tested in a scaled-up 10kW coal-fueled chemical looping combustion facility. This scaled-up evaluation tests (2-day, 8-hour per day) indicated that, there was no tendency of agglomeration of copper-based oxygen carriers. Only trace-amount of coke or carbon deposits on the copper-based oxygen carriers in the fuel reactor. There was also no evidence to show the sulphidization of oxygen carriers in the system by using the high-sulfur-laden asphalt fuels. In all, the scaled-up test in 10 kW CLC facility demonstrated that the preparation method of copper-based oxygen carrier not only help to maintain its good reactivity, also largely minimize its agglomeration tendency.« less
Lance for fuel and oxygen injection into smelting or refining furnace
Schlichting, Mark R.
1994-01-01
A furnace 10 for smelting iron ore and/or refining molten iron 20 is equipped with an overhead pneumatic lance 40, through which a center stream of particulate coal 53 is ejected at high velocity into a slag layer 30. An annular stream of nitrogen or argon 51 enshrouds the coal stream. Oxygen 52 is simultaneously ejected in an annular stream encircling the inert gas stream 51. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus 84 to react with carbon monoxide gas rising from slag layer 30, thereby adding still more heat to the furnace.
Lance for fuel and oxygen injection into smelting or refining furnace
Schlichting, M.R.
1994-12-20
A furnace for smelting iron ore and/or refining molten iron is equipped with an overhead pneumatic lance, through which a center stream of particulate coal is ejected at high velocity into a slag layer. An annular stream of nitrogen or argon enshrouds the coal stream. Oxygen is simultaneously ejected in an annular stream encircling the inert gas stream. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus to react with carbon monoxide gas rising from slag layer, thereby adding still more heat to the furnace. 7 figures.
Establishment of the roadmap for chlorination process development for zirconium recovery and recycle
DOE Office of Scientific and Technical Information (OSTI.GOV)
Collins, E.D.; Del Cul, G.D.; Spencer, B.B.
Process development studies are being conducted to recover, purify, and reuse the zirconium (about 98.5% by mass) in used nuclear fuel (UNF) zirconium alloy cladding. Feasibility studies began in FY 2010 using empty cladding hulls that were left after fuel dissolution or after oxidation to a finely divided oxide powder (voloxidation). In FY 2012, two industrial teams (AREVA and Shaw-Westinghouse) were contracted by the Department of Energy Office of Nuclear Energy (NE) to provide technical assistance to the project. In FY 2013, the NE Fuel Cycle Research and Development Program requested development of a technology development roadmap to guide futuremore » work. The first step in the roadmap development was to assess the starting point, that is, the current state of the technology and the end goal. Based on previous test results, future work is to be focused on first using chlorine as the chlorinating agent and secondly on the use of a process design that utilizes a chlorination reactor and dual ZrCl{sub 4} product salt condensers. The likely need for a secondary purification step was recognized. Completion of feasibility testing required an experiment on the chemical decladding flowsheet option. This was done during April 2013. The roadmap for process development will continue through process chemistry optimization studies, the chlorinated reactor design configuration, product salt condensers, and the off-gas trapping of tritium or other volatile fission products from the off-gas stream. (authors)« less
FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2
DOE Office of Scientific and Technical Information (OSTI.GOV)
George Rizeq; Janice West; Arnaldo Frydman
It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GEmore » EER (prime contractor) was awarded a Vision 21 program from U.S. DOE NETL to develop the UFP technology. Work on this Phase I program started on October 1, 2000. The project team includes GE EER, Southern Illinois University at Carbondale (SIU-C), California Energy Commission (CEC), and T. R. Miles, Technical Consultants, Inc. In the UFP technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on process modeling work, has an estimated process efficiency of 68%, based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal, and an estimated equivalent electrical efficiency of 60%. The Phase I R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the UFP technology. This is the tenth quarterly technical progress report for the Vision 21 UFP program supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting January 1, 2003 and ending March 31, 2003. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab-scale experimental testing, pilot-scale assembly, and program management.« less
FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2
DOE Office of Scientific and Technical Information (OSTI.GOV)
George Rizeq; Janice West; Arnaldo Frydman
It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GEmore » EER was awarded a Vision 21 program from U.S. DOE NETL to develop the UFP technology. Work on this Phase I program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the UFP technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on process modeling work, has an estimated process efficiency of 68%, based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal, and an estimated equivalent electrical efficiency of 60%. The Phase I R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the UFP technology. This is the ninth quarterly technical progress report for the Vision 21 UFP program supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting October 1, 2002 and ending December 31, 2002. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab- and bench-scale experimental testing, pilot-scale design and assembly, and program management.« less
FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2
DOE Office of Scientific and Technical Information (OSTI.GOV)
George Rizeq; Janice West; Arnaldo Frydman
It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Global Research (GEGR) has developed an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GEGR (prime contractor) was awardedmore » a Vision 21 program from U.S. DOE NETL to develop the UFP technology. Work on this Phase I program started on October 1, 2000. The project team includes GEGR, Southern Illinois University at Carbondale (SIU-C), California Energy Commission (CEC), and T. R. Miles, Technical Consultants, Inc. In the UFP technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on process modeling with best-case scenario assumptions, has an estimated process efficiency of 68%, based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal, and an estimated equivalent electrical efficiency of 60%. The Phase I R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the UFP technology. This is the eleventh quarterly technical progress report for the Vision 21 UFP program supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting April 1, 2003 and ending June 30, 2003. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab-scale experimental testing, pilot-scale assembly, and program management.« less
FUEL FLEXIBLE LOW EMISSIONS BURNER FOR WASTE-TO-ENERGY SYSTEMS - PHASE I
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1997-06-11
During this quarter, the third draft of the Topical Report on Process Economics Studies was issued for review. A recommendation to continue with design verification testing on the coproduction of methanol and dimethyl ether (DME) was made. A liquid phase dimethyl ether (LPDME) catalyst system with reasonable long-term activity and stability is being developed, and a decision to proceed with a proof-of-concept test run at the LaPorte Alternative Fuels Development Unit (AFDU) is pending the release of a memo from Air Products on the catalyst targets and corresponding economics for a commercially successful LPDME catalyst. The off-site product-use test planmore » is to be updated in June of 1997. During this quarter, Air Products and Acurex Environmental Corporation continued developing the listing of product-use test participants who are involved in fuel cell, transportation, and stationary power plant applications. Start-up activities (Task 3.1) began during the reporting period, and coal-derived synthesis gas (syngas) was introduced to the demonstration unit. The recycle compressor was tested successfully on syngas at line pressure of 700 psig, and the reactor loop reached 220 C for carbonyl burnout. Iron carbonyl in the balanced gas feed remained below the 10 ppbv detection limit for all samples but one. Within the reactor loop, iron carbonyl levels peaked out near 200 ppbv after about 40 hours on-stream, before decreasing to between 10--20 ppbv at 160 hours on -stream. Nickel carbonyl measurements reached a peak of about 60 ppbv, and decreased at all sampling locations to below the 10 ppbv detection limit by 70 hours on-stream. Catalyst activation of the nine 2,250 lb batches required for the initial catalyst charge began and concluded. All batches met or slightly exceeded the theoretical maximum uptake of 2.82 SCF of reducing gas/lb catalyst.« less
NASA Astrophysics Data System (ADS)
Janardhanan, Vinod M.; Deutschmann, Olaf
Direct internal reforming in solid oxide fuel cell (SOFC) results in increased overall efficiency of the system. Present study focus on the chemical and electrochemical process in an internally reforming anode supported SOFC button cell running on humidified CH 4 (3% H 2 O). The computational approach employs a detailed multi-step model for heterogeneous chemistry in the anode, modified Butler-Volmer formalism for the electrochemistry and Dusty Gas Model (DGM) for the porous media transport. Two-dimensional elliptic model equations are solved for a button cell configuration. The electrochemical model assumes hydrogen as the only electrochemically active species. The predicted cell performances are compared with experimental reports. The results show that model predictions are in good agreement with experimental observation except the open circuit potentials. Furthermore, the steam content in the anode feed stream is found to have remarkable effect on the resulting overpotential losses and surface coverages of various species at the three-phase boundary.
Mixing due Pulsating Turbulent Jets
NASA Astrophysics Data System (ADS)
Grosshans, Holger; Nygård, Alexander; Fuchs, Laszlo
Combustion efficiency and the formation of soot and/or NOx in Internal- Combustion engines depends strongly on the local air/fuel mixture, the local flow conditions and temperature. Modern diesel engines employ high injection pressure for improved atomization, but mixing is controlled largely by the flow in the cylinder. By injecting the fuel in pulses one can gain control over the atomization, evaporation and the mixing of the gaseous fuel. We show that the pulsatile injection of fuel enhances fuel break-up and the entrainment of ambient air into the fuel stream. The entrainment level depends on fuel property, such as fuel/air viscosity and density ratio, fuel surface-tension, injection speed and injection sequencing. Examples of enhanced break-up and mixing are given.
Shock Tunnel Studies of Scramjet Phenomena
NASA Technical Reports Server (NTRS)
Stalker, R. J.
1996-01-01
Work focussed on a large number of preliminary studies of supersonic combustion in a simple combustion duct - thrust nozzle combination, investigating effects of Mach number, equivalence ratio, combustor divergence, fuel injecting angle and other parameters with an influence on the combustion process. This phase lasted for some three or four years, during which strongest emphasis was placed on responding to the request for preliminary experimental information on high enthalpy effects, to support the technology maturation activities of the NASP program. As the need for preliminary data became less urgent, it was possible to conduct more systematic studies of high enthalpy combustion phenomena, and to initiate other projects aimed at improving the facilities and instrumentation used for studying scramjet phenomena at high enthalpies. The combustion studies were particularly directed towards hypersonic combustion, and to the effects of injecting fuel along the combustion chamber wall. A substantial effort was directed towards a study of the effect of scale on the supersonic combustion process. The influence of wave phenomena (both compression waves and expansion waves) on the realization of thrust from a supersonic combustion process was also investigated. The effect of chemical kinetics was looked into, particularly as it affected the composition of the test flow provided by a ground facility. The effect of injection of the fuel through wall orifices was compared with injection from a strut spanning the stream, and the effect of heating the fuel prior to injection was investigated. Studies of fuel-air mixing by shock impingement were also done, as well as mass spectrometer surveys of a combustion wake. The use of hypersonic nozzles with an expansion tube was investigated. A new method was developed for measuring the forces acting of a model in less than one millisecond. Also included in this report are listings of published journal papers and conference presentations.
Food and processing residues in California: resource assessment and potential for power generation.
Matteson, Gary C; Jenkins, B M
2007-11-01
The California agricultural industry produces more than 350 commodities with a combined yearly value in excess of $28 billion. The processing of many of these crops results in the production of residue streams, and the food processing industry faces increasing regulatory pressure to reduce environmental impacts and provide for sustainable management and use. Surveys of food and other processing and waste management sectors combined with published state data yield a total resource in excess of 4 million metric tons of dry matter, with nearly half of this likely to be available for utilization. About two-thirds of the available resource is produced as high-moisture residues that could support 134 MWe of power generation by anaerobic digestion and other conversion techniques. The other third is generated as low-moisture materials, many of which are already employed as fuel in direct combustion biomass power plants. The cost of energy conversion remains high for biochemical systems, with tipping or disposal fees of the order of $30-50Mg(-1) required to align power costs with current market prices. Identifying ways to reduce capital and operating costs of energy conversion, extending operating seasons to increase capacity factors through centralizing facilities, combining resource streams, and monetizing environmental benefits remain important goals for restructuring food and processing waste management in the state.
Fuel Cell Power Plant Initiative. Volume 2; Preliminary Design of a Fixed-Base LFP/SOFC Power System
NASA Technical Reports Server (NTRS)
Veyo, S.E.
1997-01-01
This report documents the preliminary design for a military fixed-base power system of 3 MWe nominal capacity using Westinghouse's tubular Solid Oxide Fuel Cell [SOFC] and Haldor Topsoe's logistic fuels processor [LFP]. The LFP provides to the fuel cell a methane rich sulfur free fuel stream derived from either DF-2 diesel fuel, or JP-8 turbine fuel. Fuel cells are electrochemical devices that directly convert the chemical energy contained in fuels such as hydrogen, natural gas, or coal gas into electricity at high efficiency with no intermediate heat engine or dynamo. The SOFC is distinguished from other fuel cell types by its solid state ceramic structure and its high operating temperature, nominally 1000'C. The SOFC pioneered by Westinghouse has a tubular geometry closed at one end. A power generation stack is formed by aggregating many cells in an ordered array. The Westinghouse stack design is distinguished from other fuel cell stacks by the complete absence of high integrity seals between cell elements, cells, and between stack and manifolds. Further, the reformer for natural gas [predominantly methane] and the stack are thermally and hydraulically integrated with no requirement for process water. The technical viability of combining the tubular SOFC and a logistic fuels processor was demonstrated at 27 kWe scale in a test program sponsored by the Advanced Research Projects Agency [ARPA) and carried out at the Southern California Edison's [SCE] Highgrove generating station near San Bernardino, California in 1994/95. The LFP was a breadboard design supplied by Haldor Topsoe, Inc. under subcontract to Westinghouse. The test program was completely successful. The LFP fueled the SOFC for 766 hours on JP-8 and 1555 hours of DF-2. In addition, the fuel cell operated for 3261 hours on pipeline natural gas. Over the 5582 hours of operation, the SOFC generated 118 MVVH of electricity with no perceptible degradation in performance. The LFP processed military specification JP-8 and DF-2 removing the sulfur and reforming these liquid fuels to a methane rich gaseous fuel. Results of this program are documented in a companion report titled 'Final Report-Solid Oxide Fuel Cell/ Logistic Fuels Processor 27 kWe Power System'.
FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2
DOE Office of Scientific and Technical Information (OSTI.GOV)
George Rizeq; Janice West; Arnaldo Frydman
It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Global Research (GEGR) has developed an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GEGR (prime contractor) was awardedmore » a contract from U.S. DOE NETL to develop the UFP technology. Work on this Phase I program started on October 1, 2000. The project team includes GEGR, Southern Illinois University at Carbondale (SIU-C), California Energy Commission (CEC), and T. R. Miles, Technical Consultants, Inc. In the UFP technology, coal and air are simultaneously converted into separate streams of (1) high-purity hydrogen that can be utilized in fuel cells or turbines, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure vitiated air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on Aspen Plus process modeling, has an estimated process efficiency of 6% higher than IGCC with conventional CO{sub 2} separation. The current R&D program will determine the feasibility of the integrated UFP technology through pilot-scale testing, and will investigate operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates experimental testing, modeling and economic studies to demonstrate the UFP technology. This is the third annual technical progress report for the UFP program supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting October 1, 2002 and ending September 30, 2003. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab-scale experimental testing, bench-scale experimental testing, process modeling, pilot-scale system design and assembly, and program management.« less
Final Progress Report, Renewable and Logistics Fuels for Fuel Cells at the Colorado School of Mines
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sullivan, Neal P.
The objective of this program is to advance the current state of technology of solid-oxide fuel cells (SOFCs) to improve performance when operating on renewable and logistics hydrocarbon fuel streams. Outcomes will include: 1.) new SOFC materials and architectures that address the technical challenges associated with carbon-deposit formation and sulfur poisoning; 2.) new integration strategies for combining fuel reformers with SOFCs; 3.) advanced modeling tools that bridge the scales of fundamental charge-transfer chemistry to system operation and control; and 4.) outreach through creation of the Distinguished Lecturer Series to promote nationwide collaboration with fuel-cell researchers and scientists.
The hospital tech laboratory: quality innovation in a new era of value-conscious care.
Keteyian, Courtland K; Nallamothu, Brahmajee K; Ryan, Andrew M
2017-08-01
For decades, the healthcare industry has been incentivized to develop new diagnostic technologies, but this limitless progress fueled rapidly growing expenditures. With an emphasis on value, the future will favor information synthesis and processing over pure data generation, and hospitals will play a critical role in developing these systems. A Michigan Medicine, IBM, and AirStrip partnership created a robust streaming analytics platform tasked with creating predictive algorithms for critical care with the potential to support clinical decisions and deliver significant value.
Solids feed nozzle for fluidized bed
Zielinski, Edward A.
1982-01-01
The vertical fuel pipe of a fluidized bed extends up through the perforated support structure of the bed to discharge granulated solid fuel into the expanded bed. A cap, as a deflecting structure, is supported above the discharge of the fuel pipe and is shaped and arranged to divert the carrier fluid and granulated fuel into the combusting bed. The diverter structure is spaced above the end of the fuel pipe and provided with a configuration on its underside to form a venturi section which generates a low pressure in the stream into which the granules of solid fuel are drawn to lengthen their residence time in the combustion zone of the bed adjacent the fuel pipe.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Alexova, J.; Sirova, M.; Rais, J.
2008-07-01
Within the framework of the ARTIST project of total fuel retreatment with ecological mixtures of solvents and extractants containing only C, H, O, and N atoms, a process segment of extraction of {sup 137}Cs from acidic stream was developed. The process with 25,27-Bis(1-octyloxy)calix[4]arene-crown- 6, DOC[4]C6, dissolved at its 0.01 M concentration in a mixture of 90 vol % 1-octanol and 10% dihexyl octanamide, DHOA was proposed as a viable variant due to its good multicycle performance, even with irradiated solvent, and due to the good chemical stability of the chosen combination of solvent mixture. (authors)
Kothmann, Richard E.; Somers, Edward V.
1982-01-01
Arrangements of stacks of fuel cells and ducts, for fuel cells operating with separate fuel, oxidant and coolant streams. An even number of stacks are arranged generally end-to-end in a loop. Ducts located at the juncture of consecutive stacks of the loop feed oxidant or fuel to or from the two consecutive stacks, each individual duct communicating with two stacks. A coolant fluid flows from outside the loop, into and through cooling channels of the stack, and is discharged into an enclosure duct formed within the loop by the stacks and seals at the junctures at the stacks.
Process for recovering actinide values
Horwitz, E. Philip; Mason, George W.
1980-01-01
A process for rendering actinide values recoverable from sodium carbonate scrub waste solutions containing these and other values along with organic compounds resulting from the radiolytic and hydrolytic degradation of neutral organophosphorous extractants such as tri-n butyl phosphate (TBP) and dihexyl-N,N-diethyl carbamylmethylene phosphonate (DHDECAMP) which have been used in the reprocessing of irradiated nuclear reactor fuels. The scrub waste solution is preferably made acidic with mineral acid, to form a feed solution which is then contacted with a water-immiscible, highly polar organic extractant which selectively extracts the degradation products from the feed solution. The feed solution can then be processed to recover the actinides for storage or recycled back into the high-level waste process stream. The extractant is recycled after stripping the degradation products with a neutral sodium carbonate solution.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dale, M.C.; Venkatesh, K.V.; Choi, H.
The basic objective of this project is to convert waste streams from the food processing industry to usable fuels and chemicals using novel bioreactors. These bioreactors should allow economical utilization of waste (whey, waste sugars, waste starch, bottling wastes, candy wastes, molasses, and cellulosic wastes) by the production of ethanol, acetone/butanol, organic acids (acetic, lactic, and gluconic), yeast diacetyl flavor, and antifungal compounds. Continuous processes incorporating various processing improvements such as simultaneous product separation and immobilized cells are being developed to allow commercial scale utilization of waste stream. The production of ethanol by a continuous reactor-separator is the process closestmore » to commercialization with a 7,500 liter pilot plant presently sited at an Iowa site to convert whey lactose to ethanol. Accomplishments during 1993 include installation and start-up of a 7,500 liter ICRS for ethanol production at an industry site in Iowa; Donation and installation of a 200 liter yeast pilot Plant to the project from Kenyon Enterprises; Modeling and testing of a low energy system for recovery of ethanol from vapor is using a solvent absorption/extractive distillation system; Simultaneous saccharification/fermentation of raw corn grits and starch in a stirred reactor/separator; Testing of the ability of `koji` process to ferment raw corn grits in a `no-cook` process.« less
High-Temperature Desulfurization of Heavy Fuel-Derived Reformate Gas Streams for SOFC Applications
NASA Technical Reports Server (NTRS)
Flytzani-Stephanopoulos, Maria; Surgenor, Angela D.
2007-01-01
Desulfurization of the hot reformate gas produced by catalytic partial oxidation or autothermal reforming of heavy fuels, such as JP-8 and jet fuels, is required prior to using the gas in a solid oxide fuel cell (SOFC). Development of suitable sorbent materials involves the identification of sorbents with favorable sulfidation equilibria, good kinetics, and high structural stability and regenerability at the SOFC operating temperatures (650 to 800 C). Over the last two decades, a major barrier to the development of regenerable desulfurization sorbents has been the gradual loss of sorbent performance in cyclic sulfidation and regeneration at such high temperatures. Mixed oxide compositions based on ceria were examined in this work as regenerable sorbents in simulated reformate gas mixtures and temperatures greater than 650 C. Regeneration was carried out with dilute oxygen streams. We have shown that under oxidative regeneration conditions, high regeneration space velocities (greater than 80,000 h(sup -1)) can be used to suppress sulfate formation and shorten the total time required for sorbent regeneration. A major finding of this work is that the surface of ceria and lanthanan sorbents can be sulfided and regenerated completely, independent of the underlying bulk sorbent. This is due to reversible adsorption of H2S on the surface of these sorbents even at temperatures as high as 800 C. La-rich cerium oxide formulations are excellent for application to regenerative H2S removal from reformate gas streams at 650 to 800 C. These results create new opportunities for compact sorber/regenerator reactor designs to meet the requirements of solid oxide fuel cell systems at any scale.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gray, McMahan L.; Shipley, Greg
Currently, landfill gases are flared-off, which creates carbon dioxide (CO 2) and particulate matter air emissions, while still containing small amounts of unburned methane (CH 4). All of these pollutants contribute to environmental health hazards and global climate change. The same is true with industrial processes that use thermal technologies to process biomass, as these also generate the pollutant gases and particulates. In conjunction with BioEnegy Development (BED), NETL researchers will adapt the Basic Immobilized Amine Sorbent (BIAS) material technology for use in BED’s biorefineries. The goal of this proposed work is to develop NETL’s immobilized hydrophobic amino-silane/amine pellets inmore » combination with BED’s biochar materials (derived from the pyrolysis of biomass) into a commercially-accepted means of capturing/recovering CH 4 and CO 2 gases from landfills. Overall, the NETL-BioEnergy Development partnership will focus on the development and application of this carbon management sorbent technology to commercial carbon capture processes and promotion of clean methane based fuel streams.« less
Full cost accounting for the life cycle of coal.
Epstein, Paul R; Buonocore, Jonathan J; Eckerle, Kevin; Hendryx, Michael; Stout Iii, Benjamin M; Heinberg, Richard; Clapp, Richard W; May, Beverly; Reinhart, Nancy L; Ahern, Melissa M; Doshi, Samir K; Glustrom, Leslie
2011-02-01
Each stage in the life cycle of coal-extraction, transport, processing, and combustion-generates a waste stream and carries multiple hazards for health and the environment. These costs are external to the coal industry and are thus often considered "externalities." We estimate that the life cycle effects of coal and the waste stream generated are costing the U.S. public a third to over one-half of a trillion dollars annually. Many of these so-called externalities are, moreover, cumulative. Accounting for the damages conservatively doubles to triples the price of electricity from coal per kWh generated, making wind, solar, and other forms of nonfossil fuel power generation, along with investments in efficiency and electricity conservation methods, economically competitive. We focus on Appalachia, though coal is mined in other regions of the United States and is burned throughout the world. © 2011 New York Academy of Sciences.
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1995-12-01
Methane emitted during underground coal mining operations is a hazard that is dealt with by diluting the methane with fresh air and exhausting the contaminated air to the atmosphere. Unfortunately this waste stream may contain more than 60% of the methane resource from the coal, and in the atmosphere the methane acts as a greenhouse gas with an effect about 24.5 times greater than CO{sub 2}. Though the waste stream is too dilute for normal recovery processes, it can be used as combustion air for a turbine-generator, thereby reducing the turbine fuel requirements while reducing emissions. Preliminary analysis indicates thatmore » such a system, built using standard equipment, is economically and environmentally attractive, and has potential for worldwide application.« less
The report gives results of tests to verify the performance of a landfill gas pretreatment unit (GPU) and a phorsphoric acid fuel cell system. The complete system removes contaminants from landfill gas and produces electricity for on-site use or connection to an electric grid. Th...
Koutinas, Apostolis A; Vlysidis, Anestis; Pleissner, Daniel; Kopsahelis, Nikolaos; Lopez Garcia, Isabel; Kookos, Ioannis K; Papanikolaou, Seraphim; Kwan, Tsz Him; Lin, Carol Sze Ki
2014-04-21
The transition from a fossil fuel-based economy to a bio-based economy necessitates the exploitation of synergies, scientific innovations and breakthroughs, and step changes in the infrastructure of chemical industry. Sustainable production of chemicals and biopolymers should be dependent entirely on renewable carbon. White biotechnology could provide the necessary tools for the evolution of microbial bioconversion into a key unit operation in future biorefineries. Waste and by-product streams from existing industrial sectors (e.g., food industry, pulp and paper industry, biodiesel and bioethanol production) could be used as renewable resources for both biorefinery development and production of nutrient-complete fermentation feedstocks. This review focuses on the potential of utilizing waste and by-product streams from current industrial activities for the production of chemicals and biopolymers via microbial bioconversion. The first part of this review presents the current status and prospects on fermentative production of important platform chemicals (i.e., selected C2-C6 metabolic products and single cell oil) and biopolymers (i.e., polyhydroxyalkanoates and bacterial cellulose). In the second part, the qualitative and quantitative characteristics of waste and by-product streams from existing industrial sectors are presented. In the third part, the techno-economic aspects of bioconversion processes are critically reviewed. Four case studies showing the potential of case-specific waste and by-product streams for the production of succinic acid and polyhydroxyalkanoates are presented. It is evident that fermentative production of chemicals and biopolymers via refining of waste and by-product streams is a highly important research area with significant prospects for industrial applications.
Self-Regulating Water-Separator System for Fuel Cells
NASA Technical Reports Server (NTRS)
Vasquez, Arturo; McCurdy, Kerri; Bradley, Karla F.
2007-01-01
proposed system would perform multiple coordinated functions in regulating the pressure of the oxidant gas (usually, pure oxygen) flowing to a fuelcell stack and in removing excess product water that is generated in the normal fuel-cell operation. The system could function in the presence or absence of gravitation, and in any orientation in a gravitational field. Unlike some prior systems for removing product water, the proposed system would not depend on hydrophobicity or hydrophilicity of surfaces that are subject to fouling and, consequently, to gradual deterioration in performance. Also unlike some prior systems, the proposed system would not include actively controlled electric motors for pumping; instead, motive power for separation and pumping away of product water would be derived primarily from the oxidant flow and perhaps secondarily from the fuel flow. The net effect of these and other features would be to make the proposed system more reliable and safer, relative to the prior systems. The proposed system (see figure) would include a pressure regulator and sensor in the oxidant supply just upstream from an ejector reactant pump. The pressure of the oxidant supply would depend on the consumption flow. In one of two control subsystems, the pressure of oxidant flowing from the supply to the ejector would be sensed and used to control the speed of a set of a reciprocating constant-displacement pump so that the volumetric flow of nominally incompressible water away from the system would slightly exceed the rate at which water was produced by the fuel cell(s). The two-phase (gas/liquid water) outlet stream from the fuel cell(s) would enter the water separator, a turbinelike centrifugal separator machine driven primarily by the oxidant gas stream. A second control subsystem would utilize feedback derived from the compressibility of the outlet stream: As the separator was emptied of liquid water, the compressibility of the pumped stream would increase. The compressibility would be sensed, and an increase in compressibility beyond a preset point (signifying a decrease in water content below an optimum low level) would cause the outflow from the reciprocating pump to be diverted back to the separator to recycle some water.
Towards a carbon-negative sustainable bio-based economy.
Vanholme, Bartel; Desmet, Tom; Ronsse, Frederik; Rabaey, Korneel; Van Breusegem, Frank; De Mey, Marjan; Soetaert, Wim; Boerjan, Wout
2013-01-01
The bio-based economy relies on sustainable, plant-derived resources for fuels, chemicals, materials, food and feed rather than on the evanescent usage of fossil resources. The cornerstone of this economy is the biorefinery, in which renewable resources are intelligently converted to a plethora of products, maximizing the valorization of the feedstocks. Innovation is a prerequisite to move a fossil-based economy toward sustainable alternatives, and the viability of the bio-based economy depends on the integration between plant (green) and industrial (white) biotechnology. Green biotechnology deals with primary production through the improvement of biomass crops, while white biotechnology deals with the conversion of biomass into products and energy. Waste streams are minimized during these processes or partly converted to biogas, which can be used to power the processing pipeline. The sustainability of this economy is guaranteed by a third technology pillar that uses thermochemical conversion to valorize waste streams and fix residual carbon as biochar in the soil, hence creating a carbon-negative cycle. These three different multidisciplinary pillars interact through the value chain of the bio-based economy.
Towards a carbon-negative sustainable bio-based economy
Vanholme, Bartel; Desmet, Tom; Ronsse, Frederik; Rabaey, Korneel; Breusegem, Frank Van; Mey, Marjan De; Soetaert, Wim; Boerjan, Wout
2013-01-01
The bio-based economy relies on sustainable, plant-derived resources for fuels, chemicals, materials, food and feed rather than on the evanescent usage of fossil resources. The cornerstone of this economy is the biorefinery, in which renewable resources are intelligently converted to a plethora of products, maximizing the valorization of the feedstocks. Innovation is a prerequisite to move a fossil-based economy toward sustainable alternatives, and the viability of the bio-based economy depends on the integration between plant (green) and industrial (white) biotechnology. Green biotechnology deals with primary production through the improvement of biomass crops, while white biotechnology deals with the conversion of biomass into products and energy. Waste streams are minimized during these processes or partly converted to biogas, which can be used to power the processing pipeline. The sustainability of this economy is guaranteed by a third technology pillar that uses thermochemical conversion to valorize waste streams and fix residual carbon as biochar in the soil, hence creating a carbon-negative cycle. These three different multidisciplinary pillars interact through the value chain of the bio-based economy. PMID:23761802
Adsorption of iodine on hydrogen-reduced silver-exchanged mordenite: Experiments and modeling
Nan, Yue; Tavlarides, Lawrence L.; DePaoli, David W.
2016-08-03
The adsorption process of iodine, a major volatile radionuclide in the off-gas streams of spent nuclear fuel reprocessing, on hydrogen-reduced silver-exchanged mordenite (Ag 0Z) was studied at the micro-scale. The gas-solid mass transfer and reaction involved in the adsorption process were investigated and evaluated with appropriate models. Optimal conditions for reducing the silver-exchanged mordenite (AgZ) in a hydrogen stream were determined. Kinetic and equilibrium data of iodine adsorption on Ag 0Z were obtained by performing single-layer adsorption experiments with experimental systems of high precision at 373–473 K over various iodine concentrations. Results indicate approximately 91% to 97% of the iodinemore » adsorption was through the silver-iodine reaction. The effect of temperature on the iodine loading capacity of Ag 0Z was discussed. In conclusion, the Shrinking Core model describes the data well, and the primary rate controlling mechanisms were macro-pore diffusion and silver-iodine reaction. © 2016 American Institute of Chemical Engineers AIChE J, 2016« less
Selection and properties of alternative forming fluids for TRISO fuel kernel production
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baker, M. P.; King, J. C.; Gorman, B. P.
2013-01-01
Current Very High Temperature Reactor (VHTR) designs incorporate TRi-structural ISOtropic (TRISO) fuel, which consists of a spherical fissile fuel kernel surrounded by layers of pyrolytic carbon and silicon carbide. An internal sol-gel process forms the fuel kernel using wet chemistry to produce uranium oxyhydroxide gel spheres by dropping a cold precursor solution into a hot column of trichloroethylene (TCE). Over time, gelation byproducts inhibit complete gelation, and the TCE must be purified or discarded. The resulting TCE waste stream contains both radioactive and hazardous materials and is thus considered a mixed hazardous waste. Changing the forming fluid to a non-hazardousmore » alternative could greatly improve the economics of TRISO fuel kernel production. Selection criteria for a replacement forming fluid narrowed a list of ~10,800 chemicals to yield ten potential replacement forming fluids: 1-bromododecane, 1- bromotetradecane, 1-bromoundecane, 1-chlorooctadecane, 1-chlorotetradecane, 1-iododecane, 1-iodododecane, 1-iodohexadecane, 1-iodooctadecane, and squalane. The density, viscosity, and surface tension for each potential replacement forming fluid were measured as a function of temperature between 25 °C and 80 °C. Calculated settling velocities and heat transfer rates give an overall column height approximation. 1-bromotetradecane, 1-chlorooctadecane, and 1-iodododecane show the greatest promise as replacements, and future tests will verify their ability to form satisfactory fuel kernels.« less
Compact hydrogen production systems for solid polymer fuel cells
NASA Astrophysics Data System (ADS)
Ledjeff-Hey, K.; Formanski, V.; Kalk, Th.; Roes, J.
Generally there are several ways to produce hydrogen gas from carbonaceous fuels like natural gas, oil or alcohols. Most of these processes are designed for large-scale industrial production and are not suitable for a compact hydrogen production system (CHYPS) in the power range of 1 kW. In order to supply solid polymer fuel cells (SPFC) with hydrogen, a compact fuel processor is required for mobile applications. The produced hydrogen-rich gas has to have a low level of harmful impurities; in particular the carbon monoxide content has to be lower than 20 ppmv. Integrating the reaction step, the gas purification and the heat supply leads to small-scale hydrogen production systems. The steam reforming of methanol is feasible at copper catalysts in a low temperature range of 200-350°C. The combination of a small-scale methanol reformer and a metal membrane as purification step forms a compact system producing high-purity hydrogen. The generation of a SPFC hydrogen fuel gas can also be performed by thermal or catalytic cracking of liquid hydrocarbons such as propane. At a temperature of 900°C the decomposition of propane into carbon and hydrogen takes place. A fuel processor based on this simple concept produces a gas stream with a hydrogen content of more than 90 vol.% and without CO and CO2.
Selection and properties of alternative forming fluids for TRISO fuel kernel production
NASA Astrophysics Data System (ADS)
Baker, M. P.; King, J. C.; Gorman, B. P.; Marshall, D. W.
2013-01-01
Current Very High Temperature Reactor (VHTR) designs incorporate TRi-structural ISOtropic (TRISO) fuel, which consists of a spherical fissile fuel kernel surrounded by layers of pyrolytic carbon and silicon carbide. An internal sol-gel process forms the fuel kernel using wet chemistry to produce uranium oxyhydroxide gel spheres by dropping a cold precursor solution into a hot column of trichloroethylene (TCE). Over time, gelation byproducts inhibit complete gelation, and the TCE must be purified or discarded. The resulting TCE waste stream contains both radioactive and hazardous materials and is thus considered a mixed hazardous waste. Changing the forming fluid to a non-hazardous alternative could greatly improve the economics of TRISO fuel kernel production. Selection criteria for a replacement forming fluid narrowed a list of ˜10,800 chemicals to yield ten potential replacement forming fluids: 1-bromododecane, 1-bromotetradecane, 1-bromoundecane, 1-chlorooctadecane, 1-chlorotetradecane, 1-iododecane, 1-iodododecane, 1-iodohexadecane, 1-iodooctadecane, and squalane. The density, viscosity, and surface tension for each potential replacement forming fluid were measured as a function of temperature between 25 °C and 80 °C. Calculated settling velocities and heat transfer rates give an overall column height approximation. 1-bromotetradecane, 1-chlorooctadecane, and 1-iodododecane show the greatest promise as replacements, and future tests will verify their ability to form satisfactory fuel kernels.
Philippe Vidon; Satish Serchan
2016-01-01
While excessive releases of greenhouse gases (GHG: N2O, CO2, CH4) to the atmosphere due to the burning of fossil fuel remains a concern, we also need to better quantify GHG emissions from natural systems. This study investigates GHG fluxes at the soilâatmosphere interface in a series of 7 stream...
Christopher R. Dolanc; Carolyn T. Hunsaker
2017-01-01
Abstract. Fixed-width buffer zones on rivers and streams are designed to protect the diverse riparian community and its important function in the ecosystem. However, recent data suggest that riparian areas of some western forests have become more fire prone because of restrictions on fuel reduction treatments within buffer zones....
Process for generating electricity in a pressurized fluidized-bed combustor system
Kasper, Stanley
1991-01-01
A process and apparatus for generating electricity using a gas turbine as part of a pressurized fluidized-bed combustor system wherein coal is fed as a fuel in a slurry in which other constituents, including a sulfur sorbent such as limestone, are added. The coal is combusted with air in a pressurized combustion chamber wherein most of the residual sulfur in the coal is captured by the sulfur sorbent. After particulates are removed from the flue gas, the gas expands in a turbine, thereby generating electric power. The spent flue gas is cooled by heat exchange with system combustion air and/or system liquid streams, and the condensate is returned to the feed slurry.
Berger, J E
1975-01-01
Although gasoline blending streams exhibit widely varying sulfur concentrations, significant quantities of low-sulfur motor gasoline cannot be manufactured by reallocation of existing components without substantial sacrifices in the useful properties of the remaining fuels having normal sulfur levels. To meet the anticipated demand for low-sulfur unleaded gasoline which may be required for catalyst-equipped automobiles it will be necessary to install process equipment based on known hydrotreating technology. The effects which this construction program would exert on the activities, abilities and needs of one petroleum refiner are sketched for two degrees of sulfur removal. The impacts of installing the process facilities which would be necessary are discussed in terms of time requirements, capital needs, and added energy expenditures. PMID:1157782
FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2
DOE Office of Scientific and Technical Information (OSTI.GOV)
George Rizeq; Janice West; Arnaldo Frydman
It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Global Research has developed an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GE Global Research (prime contractor) wasmore » awarded a contract from U.S. DOE NETL to develop the UFP technology. Work on this Phase I program started on October 1, 2000. The project team includes GE Global Research, Southern Illinois University at Carbondale (SIU-C), California Energy Commission (CEC), and T. R. Miles, Technical Consultants, Inc. In the UFP technology, coal and air are simultaneously converted into separate streams of (1) high-purity hydrogen that can be utilized in fuel cells or turbines, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure vitiated air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on ASPEN Plus process modeling, has an estimated process efficiency of 6 percentage points higher than IGCC with conventional CO{sub 2} separation. The current R&D program will determine the feasibility of the integrated UFP technology through pilot-scale testing, and will investigate operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates experimental testing, modeling and economic studies to demonstrate the UFP technology. This is the fourteenth quarterly technical progress report for the UFP program, which is supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974) and GE. This report summarizes program accomplishments for the period starting January 1, 2004 and ending March 31, 2004. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab-scale experimental testing, pilot-scale shakedown and performance testing, program management and technology transfer.« less
FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2
DOE Office of Scientific and Technical Information (OSTI.GOV)
George Rizeq; Janice West; Arnaldo Frydman
It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Global Research has developed an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GE Global Research (prime contractor) wasmore » awarded a contract from U.S. DOE NETL to develop the UFP technology. Work on this Phase I program started on October 1, 2000. The project team includes GE Global Research, Southern Illinois University at Carbondale (SIU-C), California Energy Commission (CEC), and T. R. Miles, Technical Consultants, Inc. In the UFP technology, coal and air are simultaneously converted into separate streams of (1) high-purity hydrogen that can be utilized in fuel cells or turbines, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure vitiated air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on ASPEN Plus process modeling, has an estimated process efficiency of 6% higher than IGCC with conventional CO{sub 2} separation. The current R&D program will determine the feasibility of the integrated UFP technology through pilot-scale testing, and will investigate operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates experimental testing, modeling and economic studies to demonstrate the UFP technology. This is the thirteenth quarterly technical progress report for the UFP program, which is supported by U.S. DOE NETL under Contract No. DE-FC26-00FT40974. This report summarizes program accomplishments for the period starting October 1, 2003 and ending December 31, 2003. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab-scale experimental testing, pilot-scale assembly, pilot-scale demonstration and program management and technology transfer.« less
FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2
DOE Office of Scientific and Technical Information (OSTI.GOV)
George Rizeq; Janice West; Arnaldo Frydman
It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Global Research has developed an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GE Global Research (prime contractor) wasmore » awarded a contract from U.S. DOE NETL to develop the UFP technology. Work on this Phase I program started on October 1, 2000. The project team includes GE Global Research, Southern Illinois University at Carbondale (SIU-C), California Energy Commission (CEC), and T. R. Miles, Technical Consultants, Inc. In the UFP technology, coal and air are simultaneously converted into separate streams of (1) high-purity hydrogen that can be utilized in fuel cells or turbines, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure vitiated air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on ASPEN Plus process modeling, has an estimated process efficiency of 6 percentage points higher than IGCC with conventional CO{sub 2} separation. The current R&D program has determined the feasibility of the integrated UFP technology through pilot-scale testing, and investigated operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrated experimental testing, modeling and economic studies to demonstrate the UFP technology. This is the fifteenth quarterly technical progress report for the UFP program, which is supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974) and GE. This report summarizes program accomplishments for the period starting April 1, 2004 and ending June 30, 2004. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab-scale experimental testing, pilot-scale testing, kinetic modeling, program management and technology transfer.« less
Multi-stage fuel cell system method and apparatus
George, Thomas J.; Smith, William C.
2000-01-01
A high efficiency, multi-stage fuel cell system method and apparatus is provided. The fuel cell system is comprised of multiple fuel cell stages, whereby the temperatures of the fuel and oxidant gas streams and the percentage of fuel consumed in each stage are controlled to optimize fuel cell system efficiency. The stages are connected in a serial, flow-through arrangement such that the oxidant gas and fuel gas flowing through an upstream stage is conducted directly into the next adjacent downstream stage. The fuel cell stages are further arranged such that unspent fuel and oxidant laden gases too hot to continue within an upstream stage because of material constraints are conducted into a subsequent downstream stage which comprises a similar cell configuration, however, which is constructed from materials having a higher heat tolerance and designed to meet higher thermal demands. In addition, fuel is underutilized in each stage, resulting in a higher overall fuel cell system efficiency.
High Angular Momentum Halo Gas: A Feedback and Code-independent Prediction of LCDM
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stewart, Kyle R.; Maller, Ariyeh H.; Oñorbe, Jose
We investigate angular momentum acquisition in Milky Way-sized galaxies by comparing five high resolution zoom-in simulations, each implementing identical cosmological initial conditions but utilizing different hydrodynamic codes: Enzo, Art, Ramses, Arepo, and Gizmo-PSPH. Each code implements a distinct set of feedback and star formation prescriptions. We find that while many galaxy and halo properties vary between the different codes (and feedback prescriptions), there is qualitative agreement on the process of angular momentum acquisition in the galaxy’s halo. In all simulations, cold filamentary gas accretion to the halo results in ∼4 times more specific angular momentum in cold halo gas (more » λ {sub cold} ≳ 0.1) than in the dark matter halo. At z > 1, this inflow takes the form of inspiraling cold streams that are co-directional in the halo of the galaxy and are fueled, aligned, and kinematically connected to filamentary gas infall along the cosmic web. Due to the qualitative agreement among disparate simulations, we conclude that the buildup of high angular momentum halo gas and the presence of these inspiraling cold streams are robust predictions of Lambda Cold Dark Matter galaxy formation, though the detailed morphology of these streams is significantly less certain. A growing body of observational evidence suggests that this process is borne out in the real universe.« less
Method and apparatus for fuel gas moisturization and heating
Ranasinghe, Jatila; Smith, Raub Warfield
2002-01-01
Fuel gas is saturated with water heated with a heat recovery steam generator heat source. The heat source is preferably a water heating section downstream of the lower pressure evaporator to provide better temperature matching between the hot and cold heat exchange streams in that portion of the heat recovery steam generator. The increased gas mass flow due to the addition of moisture results in increased power output from the gas and steam turbines. Fuel gas saturation is followed by superheating the fuel, preferably with bottom cycle heat sources, resulting in a larger thermal efficiency gain compared to current fuel heating methods. There is a gain in power output compared to no fuel heating, even when heating the fuel to above the LP steam temperature.
Evaluation of Ruthenium Capture Methods for Tritium Pretreatment Off-Gas Streams
DOE Office of Scientific and Technical Information (OSTI.GOV)
Spencer, Barry B.; Jubin, Robert Thomas; Bruffey, Stephanie H.
2017-07-01
In the reprocessing of used nuclear fuel, radioactive elements are released into various plant off-gas streams. While much research and development has focused on the abatement of the volatile nuclides 3H, 14C, 85Kr, and 129I, the potential release of semivolatile isotopes that could also report to the off-gas streams in a reprocessing facility has been examined. Ruthenium (as 106Ru) has been identified as one of the semivolatile nuclides requiring the greatest degree of abatement prior to discharging the plant off-gas to the environment.
Equilibrium Temperature Profiles within Fission Product Waste Forms
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kaminski, Michael D.
2016-10-01
We studied waste form strategies for advanced fuel cycle schemes. Several options were considered for three waste streams with the following fission products: cesium and strontium, transition metals, and lanthanides. These three waste streams may be combined or disposed separately. The decay of several isotopes will generate heat that must be accommodated by the waste form, and this heat will affect the waste loadings. To help make an informed decision on the best option, we present computational data on the equilibrium temperature of glass waste forms containing a combination of these three streams.
NASA Astrophysics Data System (ADS)
González-Guerrero, Maria José; del Campo, F. Javier; Esquivel, Juan Pablo; Giroud, Fabien; Minteer, Shelley D.; Sabaté, Neus
2016-09-01
This work presents a first approach towards the development of a cost-effective enzymatic paper-based glucose/O2 microfluidic fuel cell in which fluid transport is based on capillary action. A first fuel cell configuration consists of a Y-shaped paper device with the fuel and the oxidant flowing in parallel over carbon paper electrodes modified with bioelectrocatalytic enzymes. The anode consists of a ferrocenium-based polyethyleneimine polymer linked to glucose oxidase (GOx/Fc-C6-LPEI), while the cathode contains a mixture of laccase, anthracene-modified multiwall carbon nanotubes, and tetrabutylammonium bromide-modified Nafion (MWCNTs/laccase/TBAB-Nafion). Subsequently, the Y-shaped configuration is improved to use a single solution containing both, the anolyte and the catholyte. Thus, the electrolytes pHs of the fuel and the oxidant solutions are adapted to an intermediate pH of 5.5. Finally, the fuel cell is run with this single solution obtaining a maximum open circuit of 0.55 ± 0.04 V and a maximum current and power density of 225 ± 17 μA cm-2 and 24 ± 5 μW cm-2, respectively. Hence, a power source closer to a commercial application (similar to conventional lateral flow test strips) is developed and successfully operated. This system can be used to supply the energy required to power microelectronics demanding low power consumption.
NASA Astrophysics Data System (ADS)
Daniels, Charles Howard
An experimental technique is developed for evaluating the influence of mixture preparation in the intake port on the performance of a spark ignited engine. The preparation components studied are fuel vapor, droplets, and liquid streams. The fuel in these three distinct forms are produced and varied in a specially designed mixture preparation system, which delivers an air/fuel mixture to a test cylinder of an engine. Incorporated in the preparation system are devices for measuring the flow rates of fuel in these forms. A method of estimating the vapor concentration of a gasoline in the preparation channel by the use of simple temperature measurements is also presented. The effect of these fuel forms on in-cylinder pressure performance and exhaust gas concentrations are investigated in a 1.9 L Ford engine. A matrix of engine operations are studied along with two gasolines of different volatilities. The results of this investigation show that the operation of the engine at low speeds and low manifold absolute pressures is most susceptible to the effects mixture preparation. For those engine operating conditions affected, the results show that by increasing the amount of fuel in liquid stream form, the performance of the engine is generally diminished. In addition, 'equivalent' mixtures resulting from a conventional injector and a pneumatic atomizer in the intake port are identified relative to engine performance.
Catalytic combustion with incompletely vaporized residual fuel
NASA Technical Reports Server (NTRS)
Rosfjord, T. J.
1981-01-01
Catalytic combustion of fuel lean mixtures of incompletely vaporized residual fuel and air was investigated. The 7.6 cm diameter, graded cell reactor was constructed from zirconia spinel substrate and catalyzed with a noble metal catalyst. Streams of luminous particles exited the rector as a result of fuel deposition and carbonization on the substrate. Similar results were obtained with blends of No. 6 and No. 2 oil. Blends of shale residual oil and No. 2 oil resulted in stable operation. In shale oil blends the combustor performance degraded with a reduced degree of fuel vaporization. In tests performed with No. 2 oil a similar effect was observed.
Preparation of NO 2-Aged Silver-Functionalized Silica-Aerogel and Silver Mordenite Samples
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jordan, Jacob A.; Bruffey, Stephanie H.
2016-10-01
Reprocessing used nuclear fuel can result in the volatilization of radioactive gaseous species, including 129I, into the various process off-gas streams. In order to comply with US regulatory requirements, plant off-gas streams must be treated to remove the iodine prior to discharging the off-gas into the environment. The performance of available gas removal methods depends not only on the concentration of the volatile radioisotope of interest, but also on other constituents that could be present in the reprocessing off-gas streams. Some of the constituents, such as NOx produced during fuel dissolution, are known to have deleterious effects on the capturemore » performance of silver-based sorbents used for iodine removal. Commercially available reduced silver mordenite (AgZ) has an iodine saturation concentration of 7.0-9.0 wt%, and its iodine sorption capacity is reduced by 20-50% as a result of NO2 aging. Silverfunctionalized silica aerogel (AgAerogel), an alternative for iodine capture, has an initial iodine saturation of 29.0 wt% and its iodine capacity is only reduced by 15% from NO2 aging. Understanding the differences in aging behavior between AgZ and AgAerogel is critical to determining the behavior of these sorbents under realistic off-gas conditions. To assist in future technical studies on this topic, samples of both AgZ and AgAerogel were aged with NO2. In the experiment, 10.2190 g of AgZ and 10.1771 g of AgAerogel were exposed to a static 0.75% NO 2/dry air blend for a period of 28 days. The samples were then removed and stored under argon until needed for future experiments.=« less
Cetane improvement via the DIESEL-B process
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dawson, F.N. Jr.
1987-01-01
The DIESEL-B Process is a new process offered by Calsyn which is targeted toward significant cost savings - up to half the cost of conventional cetane improvers. Pay out of the low capital investments - perhaps $0.5 million - may be obtained in some cases in less than one year. The process involves on-site treating of a small slip stream - about 3% of the diesel pool. Refiners have developed quality fuels for diesel engines which would be suitable for the many diverse applications of these engines. Over the years a fair consensus of required quality specifications has evolved, mostmore » importantly those of the major pipeline operators. Ignition characteristics, as defined by cetane number or cetane index have been the most important, but other controls designed to insure stability, color, carbon content and the like are also essential constraints for the refiner. Refiners have historically been able to meet demand for motor diesel fuels by blending the higher quality virgin and hydrotreated materials with a variety of lesser quality stocks, such as cat cracker light cycle oils, coker cycle oils, thermal cycle oils and the like. But because of the typically poor engine performance properties of these latter materials, refiners have had to employ a variety of additives, most importantly cetane improvement additives, cost for which can be substantial. Calsyn is pleased to announce the development of the DIESEL-B Process for improvement of diesel fuel ignition characteristics in response to the growing need for cost cutting methods for the bread and butter portions of our business.« less
Critical review of analytical techniques for safeguarding the thorium-uranium fuel cycle
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hakkila, E.A.
1978-10-01
Conventional analytical methods applicable to the determination of thorium, uranium, and plutonium in feed, product, and waste streams from reprocessing thorium-based nuclear reactor fuels are reviewed. Separations methods of interest for these analyses are discussed. Recommendations concerning the applicability of various techniques to reprocessing samples are included. 15 tables, 218 references.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Wei; Mohagheghi, Ali; Mittal, Ashutosh
PHAs are synthesized by many microorganisms to serve as intracellular carbon storage molecules. In some bacterial strains, PHB can account for up to 80% of cell mass. In addition to its application in the packaging sector, PHB also has great potential as an intermediate in the production of hydrocarbon fuels. PHB can be thermally depolymerized and decarboxylated to propene which can be upgraded to hydrocarbon fuels via commercial oligomerization technologies. In recent years a great effort has been made in bacterial production of PHB, yet the production cost of the polymer is still much higher than conventional petrochemical plastics. Themore » high cost of PHB is because the cost of the substrates can account for as much as half of the total product cost in large scale fermentation. Thus searching for cheaper and better substrates is very necessary for PHB production. In this study, we demonstrate production of PHB by Cupriavidus necator from a process relevant lignocellulosic derived sugar stream, i.e., saccharified hydrolysate slurry from pretreated corn stover. Good cell growth was observed on slurry saccharified with advanced enzymes and 40~60% of PHB was accumulated in the cells. The mechanism of inhibition in the toxic hydrolysate generated by pretreatment and saccharification of biomass, will be discussed.« less
Microfluidic fuel cell systems
NASA Astrophysics Data System (ADS)
Ho, Bernard; Kjeang, Erik
2011-06-01
A microfluidic fuel cell is a microfabricated device that produces electrical power through electrochemical reactions involving a fuel and an oxidant. Microfluidic fuel cell systems exploit co-laminar flow on the microscale to separate the fuel and oxidant species, in contrast to conventional fuel cells employing an ion exchange membrane for this function. Since 2002 when the first microfluidic fuel cell was invented, many different fuels, oxidants, and architectures have been investigated conceptually and experimentally. In this mini-review article, recent advancements in the field of microfluidic fuel cell systems are documented, with particular emphasis on design, operation, and performance. The present microfluidic fuel cell systems are categorized by the fluidic phases of the fuel and oxidant streams, featuring gaseous/gaseous, liquid/gaseous, and liquid/liquid systems. The typical cell configurations and recent contributions in each category are analyzed. Key research challenges and opportunities are highlighted and recommendations for further work are provided.
Ignition of combustible fluids by heated surfaces
NASA Astrophysics Data System (ADS)
Bennett, Joseph Michael
The ignition of flammable fluids leaking onto hot machinery components is a common cause of fires and property loss to society. For example, the U.S. Air Force has over 100 engine fires per year. There is a comparable number in the civilian air fleet. Many of these fires are due to ruptured fuel, oil or hydraulic lines impinging on hot engine components. Also, over 500,000 vehicle fires occur each year on U.S. roads. Many of these are due to leaking fluids onto hot exhaust manifolds or other exhaust components. The design of fire protection systems for aircraft and road vehicles must take into account the problems of hot surface ignition as well as re-ignition that can occur once the fire is initially extinguished. The lack of understanding of ignition and re-ignition results in heavy, high-capacity fire extinguishers to address the fire threat. It is desired to better understand the mechanisms that control this phenomenon, and exploit this understanding in producing machinery designs that can mitigate this threat. The purpose of this effort is to gain a fundamental understanding of ignition by heated surfaces. This is done by performing experimental measurements on the impingement of vertical streams of combustible fluids onto horizontal heated surfaces, and then determine the mechanisms that control the process, in terms of physical, controllable parameters (such as fuel type, flow rate and surface temperature). An initial exhaustive review of the literature revealed a small sample of pertinent findings of previous investigators, focused on droplet ignition. Boiling modes present during contact with the heated surface were also shown to control evaporation rates and ignition delays, in addition to surface temperatures and fluid properties. An experimental apparatus was designed and constructed to create the scenario of interest in a controllable fashion, with a 20 cm horizontal heated plate with variable heating supply. Fuels were applied as streams ranging from 0.67 ml/sec to 9.5 ml/sec. Heptane, hexadecane, dodecane and kerosene were the fuels investigated in the study, and experiments were performed over a range of surface temperatures. Of the 388 fuel impingement experiments performed, 226 resulted in ignition events. Of these, 124 were classified as "airborne" ignitions, where spontaneous ignition occurred up to 60 cm above the surface. A model was derived as a predictor of ignition delays observed in these experiments, based upon a fuel evaporation rate-dominated process. This model, which utilized information derived from prior Nusselt number heat transfer correlations and simple plume models, exhibited a high degree of successful correlation with experimental data. This model was sufficiently robust to be applied to all the fuels studied, and all boiling modes (nucleate, transition and boiling) and flow rates. This facilitated a means of predicting ignition delay times based upon fundamental operating parameters of fuel type, flow rate and surface temperature, and assist in the design of fire-safe systems.
Glass Ceramic Waste Forms for Combined CS+LN+TM Fission Products Waste Streams
DOE Office of Scientific and Technical Information (OSTI.GOV)
Crum, Jarrod V.; Turo, Laura A.; Riley, Brian J.
2010-09-23
In this study, glass ceramics were explored as an alternative waste form for glass, the current baseline, to be used for immobilizing alkaline/alkaline earth + lanthanide (CS+LN) or CS+LN+transition metal (TM) fission-product waste streams generated by a uranium extraction (UREX+) aqueous separations type process. Results from past work on a glass waste form for the combined CS+LN waste streams showed that as waste loading increased, large fractions of crystalline phases precipitated upon slow cooling.[1] The crystalline phases had no noticeable impact on the waste form performance by the 7-day product consistency test (PCT). These results point towards the development ofmore » a glass ceramic waste form for treating CS+LN or CS+LN+TM combined waste streams. Three main benefits for exploring glass ceramics are: (1) Glass ceramics offer increased solubility of troublesome components in crystalline phases as compared to glass, leading to increased waste loading; (2) The crystalline network formed in the glass ceramic results in higher heat tolerance than glass; and (3) These glass ceramics are designed to be processed by the same melter technology as the current baseline glass waste form. It will only require adding controlled canister cooling for crystallization into a glass ceramic waste form. Highly annealed waste form (essentially crack free) with up to 50X lower surface area than a typical High-Level Waste (HLW) glass canister. Lower surface area translates directly into increased durability. This was the first full year of exploring glass ceramics for the Option 1 and 2 combined waste stream options. This work has shown that dramatic increases in waste loading are achievable by designing a glass ceramic waste form as an alternative to glass. Table S1 shows the upper limits for heat, waste loading (based on solubility), and the decay time needed before treatment can occur for glass and glass ceramic waste forms. The improvements are significant for both combined waste stream options in terms of waste loading and/or decay time required before treatment. For Option 1, glass ceramics show an increase in waste loading of 15 mass % and reduction in decay time of 24 years. Decay times of {approx}50 years or longer are close to the expected age of the fuel that will be reprocessed when the modified open or closed fuel cycle is expected to be put into action. Option 2 shows a 2x to 2.5x increase in waste loading with decay times of only 45 years. Note that for Option 2 glass, the required decay time before treatment is only 35 years because of the waste loading limits related to the solubility of MoO{sub 3} in glass. If glass was evaluated for similar waste loadings as those achieved in Option 2 glass ceramics, the decay time would be significantly longer than 45 years. These glass ceramics are not optimized, but already they show the potential to dramatically reduce the amount of waste generated while still utilizing the proven processing technology used for glass production.« less
Apparatus for hot-gas desulfurization of fuel gases
Bissett, Larry A.
1992-01-01
An apparatus for removing sulfur values from a hot fuel gas stream in a fdized bed contactor containing particulate sorbent material by employing a riser tube regeneration arrangement. Sulfur-laden sorbent is continuously removed from the fluidized bed through a stand pipe to the riser tube and is rapidly regenerated in the riser tube during transport of the sorbent therethrough by employing an oxygen-containing sorbent regenerating gas stream. The riser tube extends from a location below the fluidized bed to an elevation above the fluidized bed where a gas-solid separating mechanism is utilized to separate the regenerated particulate sorbent from the regeneration gases and reaction gases so that the regenerated sorbent can be returned to the fluidized bed for reuse.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yarrington, R M; Feins, I R; Hwang, H S
1979-01-01
The work done under this contract in the last quarter of 1978 was concerned with Phase I, which involved preliminary catalyst and process evaluation. The processes under study are hydrogen assisted steam reforming (HASR), catalytic partial oxidation (CPO), and autothermal steam reforming (ATR). Existing Engelhard test units were modified to carry out preliminary runs using the first two processes. Technical analysis to support work in this area consisted of heat and material balances constrained by equilibrium considerations. In a third task, the steam reforming of methanol to produce hydrogen was studied over two commercial low-temperature shift catalysts. Aging runs indicatedmore » good initial performance on both catalysts, but methanol conversion started to decline after a few hundred hours on stream.« less
NASA Astrophysics Data System (ADS)
Basu, Saptarshi
Three critical problem domains namely water transport in PEM fuel cell, interaction of vortices with diffusion flames and laminar diffusion layers and thermo-physical processes in droplets heated by a plasma or monochromatic radiation have been analyzed in this dissertation. The first part of the dissertation exhibits a unique, in situ, line-of-sight measurements of water vapor partial pressure and temperature in single and multiple gas channels on the cathode side of an operating PEM fuel cell. Tunable diode laser absorption spectroscopy was employed for these measurements for which water transitions sensitive to temperature and partial pressure were utilized. The technique was demonstrated in a PEM fuel cell operating under both steady state and time-varying load conditions. The second part of the dissertation is dedicated to the study of vortex interaction with laminar diffusion flame and non-reacting diffusion layers. For the non-reacting case, a detailed computational study of scalar mixing in a laminar vortex is presented for vortices generated between two gas streams. A detailed parametric study was conducted to determine the effects of vortex strength, convection time, and non-uniform temperature on scalar mixing characteristics. For the reacting case, an experimental study of the interaction of a planar diffusion flame with a line vortex is presented. The flame-vortex interactions are diagnosed by laser induced incandescence for soot yield and by particle image velocimetry for vortex flow characterization. The soot topography was studied as a function of the vortex strength, residence time, flame curvature and the reactant streams from which vortices are initiated. The third part of the dissertation is modeling of thermo-physical processes in liquid ceramic precursor droplets injected into plasma as used in the thermal spray industry to generate thermal barrier coatings on high value materials. Models include aerodynamic droplet break-up process, mixing of droplets in the high temperature plasma, heat and mass transfer within individual droplets as well as droplet precipitation and internal pressurization. The last part of the work is also concerned with the modeling of thermo-physical processes in liquid ceramic precursor droplets heated by monochromatic radiation. Purpose of this work was to evaluate the feasibility of studying precipitation kinetics and morphological changes in a droplet by mimicking similar heating rates as the plasma.
Terrestrial–aquatic linkages in spring-fed and snowmelt-dominated streams
Sepulveda, Adam
2017-01-01
The importance of trophic linkages between aquatic and terrestrial ecosystems is predicted to vary as a function of subsidy quantity and quality relative to in situ resources. To test this prediction, I used multi-year diet data from Bonneville cutthroat trout Oncorhynchus clarki Utah in spring-fed and snowmelt-driven streams in the high desert of western North America. I documented that trout in spring-fed streams consumed more (number and weight) aquatic than terrestrial invertebrates, while trout in snowmelt-driven streams consumed a similar number of both prey types but consumed more terrestrial than aquatic invertebrates by weight. Trout in spring-fed streams consumed more aquatic invertebrates than trout in snowmelt streams and trout consumed more terrestrial invertebrates in snowmelt than in spring-fed streams. Up to 93% of trout production in spring-fed streams and 60% in snowmelt streams was fueled by aquatic invertebrates, while the remainder of trout production in each stream type was from terrestrial production. I found that the biomass and occurrence of consumed terrestrial invertebrates were not related to our measures of in situ resource quality or quantity in either stream type. These empirical data highlight the importance of autotrophic-derived production to trout in xeric regions.
Altitude engine test of a turbofan exhaust gas mixer to conserve fuel
NASA Technical Reports Server (NTRS)
Cullom, R. R.; Johnsen, R. L.
1977-01-01
A comparison of the specific fuel consumption was made with and without an internal mixer installed in a low bypass ratio, confluent flow turbofan engine. Tests were conducted at several Mach numbers and altitudes for core to fan stream total temperature ratios of 2.0 and 2.5 and mixing lengths of L/D = 0.95 and 1.74. For these test conditions, the specific fuel consumption improvement varied from 2.5 to 4.0 percent.
NASA Technical Reports Server (NTRS)
Mularz, Edward J.; Sockol, Peter M.
1987-01-01
Future aerospace propulsion concepts involve the combination of liquid or gaseous fuels in a highly turbulent internal air stream. Accurate predictive computer codes which can simulate the fluid mechanics, chemistry, and turbulence combustion interaction of these chemical reacting flows will be a new tool that is needed in the design of these future propulsion concepts. Experimental and code development research is being performed at Lewis to better understand chemical reacting flows with the long term goal of establishing these reliable computer codes. The approach to understanding chemical reacting flows is to look at separate simple parts of this complex phenomena as well as to study the full turbulent reacting flow process. As a result research on the fluid mechanics associated with chemical reacting flows was initiated. The chemistry of fuel-air combustion is also being studied. Finally, the phenomena of turbulence-combustion interaction is being investigated. This presentation will highlight research, both experimental and analytical, in each of these three major areas.
pH-dependent ammonia removal pathways in microbial fuel cell system.
Kim, Taeyoung; An, Junyeong; Lee, Hyeryeong; Jang, Jae Kyung; Chang, In Seop
2016-09-01
In this work, ammonia removal paths in microbial fuel cells (MFCs) under different initial pH conditions (pH 7.0, 8.0, and 8.6) were investigated. At a neutral pH condition (pH 7.0), MFC used an electrical energy of 27.4% and removed 23.3% of total ammonia by electrochemical pathway for 192h. At the identical pH condition, 36.1% of the total ammonia was also removed by the biological path suspected to be biological ammonia oxidation process (e.g., Anammox). With the initial pH increased, the electrochemical removal efficiency decreased to less than 5.0%, while the biological removal efficiency highly increased to 61.8%. In this study, a neutral pH should be maintained in the anode to utilize MFCs for ammonia recovery via electrochemical pathways from wastewater stream. Copyright © 2016 Elsevier Ltd. All rights reserved.
Detectability of cold streams into high-redshift galaxies by absorption lines
NASA Astrophysics Data System (ADS)
Goerdt, Tobias; Dekel, Avishai; Sternberg, Amiel; Gnat, Orly; Ceverino, Daniel
2012-08-01
Cold gas streaming along the dark matter filaments of the cosmic web is predicted to be the major source of fuel for disc buildup, violent disc instability and star formation in massive galaxies at high redshift. We investigate to what extent such cold gas is detectable in the extended circumgalactic environment of galaxies via Lyα absorption and selected low-ionization metal absorption lines. We model the expected absorption signatures using high-resolution zoom-in adaptive mesh refinement cosmological simulations. In the post-processing, we distinguish between self-shielded gas and unshielded gas. In the self-shielded gas, which is optically thick to Lyman continuum radiation, we assume pure collisional ionization for species with an ionization potential greater than 13.6 eV. In the optically-thin, unshielded gas, these species are also photoionized by the metagalactic radiation. In addition to absorption of radiation from background quasars, we compute the absorption line profiles of radiation emitted by the galaxy at the centre of the same halo. We predict the strength of the absorption signal for individual galaxies without stacking. We find that the Lyα absorption profiles produced by the streams are consistent with observations of absorption and emission Lyα profiles in high-redshift galaxies. Due to the low metallicities in the streams, and their low covering factors, the metal absorption features are weak and difficult to detect.
Shock tunnel studies of scramjet phenomena, supplement 6
NASA Technical Reports Server (NTRS)
Wendt, M.; Nettleton, M.; Morgan, R. G.; Skinner, K.; Casey, R.; Stalker, R.; Brescianini, C.; Paull, A.; Allen, G.; Smart, M.
1993-01-01
Reports by the staff of the University of Queensland on various research studies related to the advancement of scramjet technology are presented. These reports document the tests conducted in the reflected shock tunnel T4 and supporting research facilities that have been used to study the injection, mixing, and combustion of hydrogen fuel in generic scramjets at flow conditions typical of hypersonic flight. In addition, topics include the development of instrumentation and measurement technology, such as combustor wall shear and stream composition in pulse facilities, and numerical studies and analyses of the scramjet combustor process and the test facility operation.
Magnesium in North America: A Changing Landscape
NASA Astrophysics Data System (ADS)
Slade, Susan
The changing landscape of North American manufacturing in the context of global competition is impacting the market of all raw materials, including magnesium. Current automotive fuel economy legislation and pending legislation on the emissions of greenhouse gases are impacting magnesium's largest consuming industries, such as aluminum, automotive components, steel and transition metals. These industries are all considering innovative ways to efficiently incorporate the needed raw materials into their processes. The North American magnesium market differs from other regions based on maturity, supply streams, changing manufacturing capabilities and trade cases, combined with the transformation of North American manufacturing.
Argon recovery from hydrogen depleted ammonia plant purge gas using a HARP Plant
DOE Office of Scientific and Technical Information (OSTI.GOV)
Krishnamurthy, R.; Lerner, S.L.; Maclean, D.L.
1987-01-01
A number of ammonia plants employ membranes or cryogenic hydrogen recovery units to separate hydrogen contained in the purge gas for recycle to the ammonia synthesis loop. The resulting hydrogen depleted purge gas, which is usually used for fuel, is an attractive source of argon. This paper presents the novel features of a process which employs a combination of pressure swing adsorption (PSA) and cryogenic technology to separate the argon from this hydrogen depleted purge gas stream. This new proprietary Hybrid Argon Recovery Progress (HARP) plant is an effective alternative to a conventional all-cryogenic plant.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tan, Eric C. D.; Talmadge, Michael; Dutta, Abhijit
This paper describes in detail one potential conversion process for the production of high-octane gasoline blendstock via indirect liquefaction of biomass. The processing steps of this pathway include the conversion of biomass to synthesis gas via indirect gasification, gas clean-up via reforming of tars and other hydrocarbons, catalytic conversion of syngas to methanol, methanol dehydration to dimethyl ether (DME), and the homologation of DME over a zeolite catalyst to high-octane gasoline-range hydrocarbon products. The current process configuration has similarities to conventional methanol-to-gasoline (MTG) technologies, but there are key distinctions, specifically regarding the product slate, catalysts, and reactor conditions. A techno-economicmore » analysis is performed to investigate the production of high-octane gasoline blendstock. The design features a processing daily capacity of 2000 tonnes (2205 short tons) of dry biomass. The process yields 271 liters of liquid fuel per dry tonne of biomass (65 gal/dry ton), for an annual fuel production rate of 178 million liters (47 MM gal) at 90% on-stream time. The estimated total capital investment for an nth-plant is $438 million. The resulting minimum fuel selling price (MFSP) is $0.86 per liter or $3.25 per gallon in 2011 US dollars. A rigorous sensitivity analysis captures uncertainties in costs and plant performance. Sustainability metrics for the conversion process are quantified and assessed. The potential premium value of the high-octane gasoline blendstock is examined and found to be at least as competitive as fossil-derived blendstocks. A simple blending strategy is proposed to demonstrate the potential for blending the biomass-derived blendstock with petroleum-derived intermediates. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.« less
Self-regulating fuel staging port for turbine combustor
DOE Office of Scientific and Technical Information (OSTI.GOV)
Van Nieuwenhuizen, William F.; Fox, Timothy A.; Williams, Steven
2014-07-08
A port (60) for axially staging fuel and air into a combustion gas flow path 28 of a turbine combustor (10A). A port enclosure (63) forms an air path through a combustor wall (30). Fuel injectors (64) in the enclosure provide convergent fuel streams (72) that oppose each other, thus converting velocity pressure to static pressure. This forms a flow stagnation zone (74) that acts as a valve on airflow (40, 41) through the port, in which the air outflow (41) is inversely proportion to the fuel flow (25). The fuel flow rate is controlled (65) in proportion to enginemore » load. At high loads, more fuel and less air flow through the port, making more air available to the premixing assemblies (36).« less
NASA Technical Reports Server (NTRS)
Tacina, R.
1976-01-01
A premixing-prevaporizing fuel system for a gas turbine catalytic combustor has been developed and evaluated. Spatial fuel distribution and degree of vaporization were measured at inlet temperatures up to 800 K and fuel-air ratios of 0.01 and 0.025. The test pressure was 0.5 MPa; velocity was 20 m/sec. Both a multiple-jet cross-stream injector and a splash-groove injector with a 30 deg air swirler exhibited a uniform fuel distribution and a high degree of vaporization with little total pressure drop. Fuel oxidation reactions were observed at the 800 K inlet air temperature, indicating that a different design concept is necessary for application with an automotive gas turbine.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jones, J.F.; Wever, D.M.
1981-07-01
Three processes developed by Pittsburgh Energy Technology Center (PETC), Ledgemont Laboratories, and Ames Laboratories for the oxydesulfurization of coal were evaluated in continuous processing equipment designed, built, and/or adapted for the purpose at the DOE-owned Multi-Use Fuels and Energy Processes Test Plant (MEP) located at TRW's Capistrano Test Site in California. The three processes differed primarily in the chemical additives (none, sodium carbonate, or ammonia), fed to the 20% to 40% coal/water slurries, and in the oxygen content of the feed gas stream. Temperature, pressure, residence time, flow rates, slurry concentration and stirrer speed were the other primary independent variables.more » The amount of organic sulfur removed, total sulfur removed and the Btu recovery were the primary dependent variables. Evaluation of the data presented was not part of the test effort.« less
O'Brien, Anne K.; Reiser, Robert G.; Gylling, Helle
1997-01-01
Volatile organic compounds (VOCs) are found in almost all natural and synthetic materials and are commonly used in fuels, fuel additives, solvents, perfumes, flavor additives, and deodorants. Potential health hazards and environmental degradation resulting from the widespread use of VOCs has prompted increasing concern among scientists, industry, and the general public.
Production of High Density Aviation Fuels via Novel Zeolite Catalyst Routes
1989-10-23
range fraction of a naphthenic crude; saturation of an aromatic FCC cycle stock I the appropriate boiling range: saturation of an appropriate boiling...aromatic hydrocarbons and selected aromatic feedstocks to the corresponding mono- and dicyclic naphthenes in the aviation turbine fuel boiling range; and...Paraffins from Naphthenic Refinery Feed Streams .......... 8 Solvent Extraction ........................................... 8 Shape Selective Catalytic
A model for 3-D sonic/supersonic transverse fuel injection into a supersonic air stream
NASA Technical Reports Server (NTRS)
Bussing, Thomas R. A.; Lidstone, Gary L.
1989-01-01
A model for sonic/supersonic transverse fuel injection into a supersonic airstream is proposed. The model replaces the hydrogen jet up to the Mach disk plane and the elliptic parts of the air flow field around the jet by an equivalent body. The main features of the model were validated on the basis of experimental data.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yamanishi, Toshihiko; Hayashi, Takumi; Kawamura, Yoshinori
2005-07-15
A simulated fuel processing (cryogenic distillation columns and a palladium diffuser) and CMSB (cryogenic molecular sieve bed) systems were linked together, and were operated. The validity of the CMSB was discussed through this experiment as an integrated system for the recovery of blanket tritium. A gas stream of hydrogen isotopes and He was supplied to the CMSB as the He sweep gas in blanket of a fusion reactor. After the breakthrough of tritium was observed, regeneration of the CMSB was carried out by evacuating and heating. The hydrogen isotopes were finally recovered by the diffuser. At first, only He gasmore » was sent by the evacuating. The hydrogen isotopes gas was then rapidly released by the heating. The system worked well against the above drastic change of conditions. The amount of hydrogen isotopes gas finally recovered by the diffuser was in good agreement with that adsorbed by the CMSB. The dynamic behaviors (breakthrough and regeneration) of the system were explained well by a set of basic codes.« less
Discretized Streams: A Fault-Tolerant Model for Scalable Stream Processing
2012-12-14
Discretized Streams: A Fault-Tolerant Model for Scalable Stream Processing Matei Zaharia Tathagata Das Haoyuan Li Timothy Hunter Scott Shenker Ion...SUBTITLE Discretized Streams: A Fault-Tolerant Model for Scalable Stream Processing 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER...time. However, current programming models for distributed stream processing are relatively low-level often leaving the user to worry about consistency of
Fischer-Tropsch Catalyst for Aviation Fuel Production
NASA Technical Reports Server (NTRS)
DeLaRee, Ana B.; Best, Lauren M.; Bradford, Robyn L.; Gonzalez-Arroyo, Richard; Hepp, Aloysius F.
2012-01-01
As the oil supply declines, there is a greater need for cleaner alternative fuels. There will undoubtedly be a shift from crude oil to nonpetroleum sources as a feedstock for aviation (and other transportation) fuels. The Fischer-Tropsch process uses a gas mixture of carbon monoxide and hydrogen which is converted into various liquid hydrocarbons; this versatile gas-to-liquid technology produces a complex product stream of paraffins, olefins, and oxygenated compounds such as alcohols and aldehydes. The Fischer-Tropsch process can produce a cleaner diesel oil fraction with a high cetane number (typically above 70) without any sulfur and aromatic compounds. It is most commonly catalyzed by cobalt supported on alumina, silica, or titania or unsupported alloyed iron powders. Cobalt is typically used more often than iron, in that cobalt is a longer-active catalyst, has lower water-gas shift activity, and lower yield of modified products. Promoters are valuable in improving Fischer-Tropsch catalyst as they can increase cobalt oxide dispersion, enhance the reduction of cobalt oxide to the active metal phase, stabilize a high metal surface area, and improve mechanical properties. Our goal is to build up the specificity of the Fischer-Tropsch catalyst while adding less-costly transition metals as promoters; the more common promoters used in Fischer-Tropsch synthesis are rhenium, platinum, and ruthenium. In this report we will describe our preliminary efforts to design and produce catalyst materials to achieve our goal of preferentially producing C8 to C18 paraffin compounds in the NASA Glenn Research Center Gas-To-Liquid processing plant. Efforts at NASA Glenn Research Center for producing green fuels using non-petroleum feedstocks support both the Sub-sonic Fixed Wing program of Fundamental Aeronautics and the In Situ Resource Utilization program of the Exploration Technology Development and Demonstration program.
Fischer-Tropsch Catalyst for Aviation Fuel Production
NASA Technical Reports Server (NTRS)
deLaRee, Ana B.; Best, Lauren M.; Hepp, Aloysius F.
2011-01-01
As the oil supply declines, there is a greater need for cleaner alternative fuels. There will undoubtedly be a shift from crude oil to non-petroleum sources as a feedstock for aviation (and other transportation) fuels. The Fischer-Tropsch process uses a gas mixture of carbon monoxide and hydrogen which is converted into various liquid hydrocarbons; this versatile gas-to-liquid technology produces a complex product stream of paraffins, olefins, and oxygenated compounds such as alcohols and aldehydes. The Fischer-Tropsch process can produce a cleaner diesel oil fraction with a high cetane number (typically above 70) without any sulfur and aromatic compounds. It is most commonly catalyzed by cobalt supported on alumina, silica, or titania or unsupported alloyed iron powders. Cobalt is typically used more often than iron, in that cobalt is a longer-active catalyst, has lower water-gas shift activity, and lower yield of modified products. Promoters are valuable in improving Fischer-Tropsch catalyst as they can increase cobalt oxide dispersion, enhance the reduction of cobalt oxide to the active metal phase, stabilize a high metal surface area, and improve mechanical properties. Our goal is to build up the specificity of the Fischer-Tropsch catalyst while adding less-costly transition metals as promoters; the more common promoters used in Fischer-Tropsch synthesis are rhenium, platinum, and ruthenium. In this report we will describe our preliminary efforts to design and produce catalyst materials to achieve our goal of preferentially producing C8 to C18 paraffin compounds in the NASA Glenn Research Center Gas-To-Liquid processing plant. Efforts at NASA Glenn Research Center for producing green fuels using non-petroleum feedstocks support both the Sub-sonic Fixed Wing program of Fundamental Aeronautics and the In Situ Resource Utilization program of the Exploration Technology Development and Demonstration program.
Gravity Effects Observed In Partially Premixed Flames
NASA Technical Reports Server (NTRS)
Puri, Ishwar K.; Aggarwal, Suresh K.; Lock, Andrew J.; Gauguly, Ranjan; Hegde, Uday
2003-01-01
Partially premixed flames (PPFs) contain a rich premixed fuel air mixture in a pocket or stream, and, for complete combustion to occur, they require the transport of oxidizer from an appropriately oxidizer-rich (or fuel-lean) mixture that is present in another pocket or stream. Partial oxidation reactions occur in fuel-rich portions of the mixture and any remaining unburned fuel and/or intermediate species are consumed in the oxidizer-rich portions. Partial premixing, therefore, represents that condition when the equivalence ratio (phi) in one portion of the flowfield is greater than unity, and in another section its value is less than unity. In general, for combustion to occur efficiently, the global equivalence ratio is in the range fuel-lean to stoichiometric. These flames can be established by design by placing a fuel-rich mixture in contact with a fuel-lean mixture, but they also occur otherwise in many practical systems, which include nonpremixed lifted flames, turbulent nonpremixed combustion, spray flames, and unwanted fires. Other practical applications of PPFs are reported elsewhere. Although extensive experimental studies have been conducted on premixed and nonpremixed flames under microgravity, there is a absence of previous experimental work on burner stabilized PPFs in this regard. Previous numerical studies by our group employing a detailed numerical model showed gravity effects to be significant on the PPF structure. We report on the results of microgravity experiments conducted on two-dimensional (established on a Wolfhard-Parker slot burner) and axisymmetric flames (on a coannular burner) that were investigated in a self-contained multipurpose rig. Thermocouple and radiometer data were also used to characterize the thermal transport in the flame.
Pence, Dallas T.; Thomas, Thomas R.
1980-01-01
Noxious nitrogen oxides in a waste gas stream such as the stack gas from a fossil-fuel-fired power generation plant or other industrial plant off-gas stream is catalytically reduced to elemental nitrogen and/or innocuous nitrogen oxides employing ammonia as reductant in the presence of a zeolite catalyst in the hydrogen or sodium form having pore openings of about 3 to 10 A.
Impact of 50% Synthesized Iso-Paraffins (SIP) on Middle Distillate Fuel Filtration and Coalescence
2014-10-30
Paraffins DEFINITIONS Coalescence - the ability to shed water Conventional Material Source - crude oil, natural gas liquid condensates...heavy oil, shale oil, and oil sands Effluent - stream leaving a system Influent - stream entering a system Turnover - time required to flow the...separators are used onboard naval vessels (required onboard gas turbine ships and some diesel engine ships) and at shore stations to reduce solid and free
DOE Office of Scientific and Technical Information (OSTI.GOV)
Benoit Forget; Mehdi Asgari; Rodolfo M. Ferrer
2007-11-01
As part of the GNEP program, it is envisioned to build a fast reactor for the transmutation of minor actinides. The spent nuclear fuel from the current fleet of light water reactors would be recycled, the current baseline is the UREX+1a process, and would act as a feed for the fast reactor. As the fuel is irradiated in a fast reactor a certain quantity of minor actinides would thus build up in the fuel stream creating possible concerns with the neutron emission of these minor actinides for fuel transportation, handling and fabrication. Past neutronic analyses had not tracked minor actinidesmore » above Cm-246 in the transmutation chain, because of the small influence on the overall reactor performance and cycle parameters. However, when trying to quantify the neutron emission from the recycled fuel with high minor actinide content, these higher isotopes play an essential role and should be included in the analysis. In this paper, the influence of tracking these minor actinides on the calculated neutron emission is presented. Also presented is the particular influence of choosing a different evaluated cross section data set to represent the minor actinides above Cm-246. The first representation uses the cross-sections provided by MC2-2 for all isotopes, while the second representation uses infinitely diluted ENDF/BVII.0 cross-sections for Cm-247 to Cf-252 and MC2-2 for all other isotopes.« less
Capture of Tritium Released from Cladding in the Zirconium Recycle Process
DOE Office of Scientific and Technical Information (OSTI.GOV)
Spencer, Barry B.; Walker, T. B.; Bruffey, S. H.
2016-08-31
Zirconium may be recovered from the Zircaloy® cladding of used nuclear fuel (UNF) for recycle or to reduce the quantities of high-level waste destined for a geologic repository. Recovery of zirconium using a chlorination process is currently under development at the Oak Ridge National Laboratory. The approach is to treat the cladding with chlorine gas to convert the zirconium in the alloy (~98 wt % of the alloy mass) to zirconium tetrachloride. A significant fraction of the tritium (0–96%) produced in nuclear fuel during irradiation may be found in zirconium-based cladding and could be released from the cladding when themore » solid matrix is destroyed by the chlorination reaction. To prevent uncontrolled release of radioactive tritium to other parts of the plant or to the environment, a method to recover the tritium may be required. The focus of this effort was to (1) identify potential methods for the recovery of tritium from the off-gas of the zirconium recycle process, (2) perform scoping tests on selected recovery methods using nonradioactive gas simulants, and (3) select a process design appropriate for testing on radioactive gas streams generated by the engineering-scale zirconium recycle demonstrations on radioactive used cladding.« less
Capture of Tritium Released from Cladding in the Zirconium Recycle Process
DOE Office of Scientific and Technical Information (OSTI.GOV)
Spencer, Barry B.; Walker, T. B.; Bruffey, Stephanie H.
2016-08-31
This report is issued as the first revision to FCRD-MRWFD-2016-000297. Zirconium may be recovered from the Zircaloy® cladding of used nuclear fuel (UNF) for recycle or to reduce the quantities of high-level waste destined for a geologic repository. Recovery of zirconium using a chlorination process is currently under development at the Oak Ridge National Laboratory. The approach is to treat the cladding with chlorine gas to convert the zirconium in the alloy (~98 wt % of the alloy mass) to zirconium tetrachloride. A significant fraction of the tritium (0–96%) produced in nuclear fuel during irradiation may be found in zirconium-basedmore » cladding and could be released from the cladding when the solid matrix is destroyed by the chlorination reaction. To prevent uncontrolled release of radioactive tritium to other parts of the plant or to the environment, a method to recover the tritium may be required. The focus of this effort was to (1) identify potential methods for the recovery of tritium from the off-gas of the zirconium recycle process, (2) perform scoping tests on selected recovery methods using non-radioactive gas simulants, and (3) select a process design appropriate for testing on radioactive gas streams generated by the engineering-scale zirconium recycle demonstrations on radioactive used cladding.« less
Understanding of ammonia transport in PEM fuel cells
NASA Astrophysics Data System (ADS)
Jung, Myunghee
This dissertation investigates ammonia (NH3) as a fuel contaminant to the anode in Proton Exchange Membrane Fuel Cells (PEMFCs). Since NH 3 is fed to the anode in a gas phase and transferred to the cathode, the effect of a contaminant is distributed through MEA and quite complicated. This study is focused on the investigation of mechanism of NH3 transport and the isolation of multiple effects to degrade the performance of fuel cell. An External Reference Electrode (ERE) was employed to decouple the effect of individual electrode and explain the mechanism of NH3 contamination. A mechanism of NH3 transport is proposed and supported by data for various inlet conditions in a N2/N2 laboratory-scale fuel cell at Open Circuit Conditions (OCC). With a commercialized GORE(TM) PRIMEA RTM 5631 MEAs at 70°C, data were obtained utilizing a material balance technique, which uses an ion selective electrode (ISE) to determine the concentration of ammonium ion in the process streams. The results indicate that ammonia is not transported across the membrane when the feeds to both electrodes are dry. However, with humidified feeds ammonia was transported from the anode to the cathode. The data also indicate the water content of in the MEA is the critical factor that causes NH3 crossover in the MEA. Diffusion coefficients of NH3 in MEA are also calculated at different relative humilities. An ERE was developed for PEM fuel cell by using a NafionRTM strip which was used to understand contamination mechanism. The voltage of anode electrode relative to ERE was measured during a polarization curve. The data showed the measurement of individual electrode potential was extremely affected by the misalignment between two electrodes. We compare the overpotential measured from the reference electrode and the calculated overpotential from subtracting the cell voltages between neat hydrogen and a 25 ppm CO in H 2 stream at same current. The studies indicated that the overpotentials obtained from two different methods were same and the location of a Nafion RTM strip on MEA did not affect the measured overpotentials. When NH3 was introduced as a contaminant to the cell at OCC, the thermodynamic potential of the anode electrode was measured for GORETM PRIMEARTM 57 series MEA at 80°C. High Frequency Resistance (HFR) and material balance were also analyzed during the change of thermodynamic potential. The results show that the injected NH3 was absorbed in the MEA until the ion exchange capacity was fully saturated and then NH 3 reaction occurred on the electrode. Finally, we studied how NH 3 contamination process occurs from transient voltage changes of the cell and an individual electrode.
Cryogenic reactant storage for lunar base regenerative fuel cells
NASA Technical Reports Server (NTRS)
Kohout, Lisa L.
1989-01-01
There are major advantages to be gained by integrating a cryogenic reactant storage system with a hydrogen-oxygen regenerative fuel cell (RFC) to provide on-site electrical power during the lunar night. Although applicable to any power system using hydrogen-oxygen RFC's for energy storage, cryogenic reactant storage offers a significant benefit whenever the sun/shade cycle and energy storage period approach hundreds of hours. For solar power installations on the moon, cryogenic reactant storage reduces overall specific mass and meteoroid vulnerability of the system. In addition, it offers synergistic benefits to on-site users, such as availability of primary fuel cell reactants for surface rover vehicles and cryogenic propellants for OTV's. The integration involves processing and storing the RFC reactant streams as cryogenic liquids rather than pressurized gases, so that reactant containment (tankage per unit mass of reactants) can be greatly reduced. Hydrogen-oxygen alkaline RFC's, GaAs photovoltaic (PV) arrays, and space cryogenic processing/refrigeration technologies are assumed to be available for the conceptual system design. Advantages are demonstrated by comparing the characteristics of two power system concepts: a conventional lunar surface PV/RFC power system using pressurized gas storage in SOA filament wound pressure vessels and, that same system with gas liquefaction and storage replacing the pressurized storage. Comparisons are made at 20 and 250 kWe. Although cryogenic storage adds a processing plant (drying and liquefaction) to the system plus 30 percent more solar array to provide processing power, the approximate order of magnitude reduction in tankage mass, confirmed by this analysis, results in a reduction in overall total system mass of approximately 50 percent.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bruffey, Stephanie H.; Patton, Kaara K.; Jubin, Robert Thomas
In off-gas treatment systems within a nuclear fuel reprocessing plant, capture materials will be exposed to a gas stream for extended periods during their lifetime. This gas stream may be at elevated temperature and could contain water, NOx gas, or a variety of other constituents. For this reason, it is important to understand the effects of long-term exposure, or aging, on proposed capture materials. One material under consideration for iodine sequestration is silver-functionalized silica aerogel (Ag 0-aerogel). The aim of this study was to determine the effect of extended exposure at 150°C to an air stream containing NO on themore » iodine capture capacity of Ag 0-aerogel. Ag 0-aerogel was provided by the Pacific Northwest National Laboratory (PNNL), which manufactures the material at a lab scale. Prior to aging, the material has an iodine loading capacity of approximately 290 mg I/g Ag 0-aerogel. Previous studies have aged the material in a dry air stream or in a moist air stream for up to 6 months. Both tests resulted in a 22% loss in iodine capacity. Aging the material in a static 2% NO 2 environment for up to 2 months results in a 15% loss of iodine capacity.3 In this study, exposure of Ag 0-aerogel to 1% NO at 150°C for 2 months produced a loss of 43% in iodine loading capacity. This is largest loss observed for aerogel aging studies to date. The performance of Ag 0-aerogel in this study was compared to the performance of reduced silver mordenite (Ag 0Z) in similar studies. Ag 0Z is a zeolite mineral considered to be the current standard technology for iodine removal from off-gas streams of a potential US used fuel processing plant. In an aging study exposing Ag 0Z to 1% NO for 2 months, an iodine capacity loss of over 80% was observed. This corresponds to a silver utilization of 13.5% for 2 month NO-aged Ag 0Z, compared to 57% silver utilization for 2 month NO-aged aerogel. While iodine loading capacity and silver utilization are critical parameters in evaluating these materials, other properties must also be considered when selecting the appropriate material (e.g., relative material densities and potential waste form production technology). The resistance of Ag 0-aerogel to NO is promising, and investigations of this material for use in iodine capture should continue to be pursued.« less
Dale, James G; Cox, Steven S; Vance, Marina E; Marr, Linsey C; Hochella, Michael F
2017-02-21
Nanoscale cerium oxide is used as a diesel fuel additive to reduce particulate matter emissions and increase fuel economy, but its fate in the environment has not been established. Cerium oxide released as a result of the combustion of diesel fuel containing the additive Envirox, which utilizes suspended nanoscale cerium oxide to reduce particulate matter emissions and increase fuel economy, was captured from the exhaust stream of a diesel engine and was characterized using a combination of bulk analytical techniques and high resolution transmission electron microscopy. The combustion process induced significant changes in the size and morphology of the particles; ∼15 nm aggregates consisting of 5-7 nm faceted crystals in the fuel additive became 50-300 nm, near-spherical, single crystals in the exhaust. Electron diffraction identified the original cerium oxide particles as cerium(IV) oxide (CeO 2 , standard FCC structure) with no detectable quantities of Ce(III), whereas in the exhaust the ceria particles had additional electron diffraction reflections indicative of a CeO 2 superstructure containing ordered oxygen vacancies. The surfactant coating present on the cerium oxide particles in the additive was lost during combustion, but in roughly 30% of the observed particles in the exhaust, a new surface coating formed, approximately 2-5 nm thick. The results of this study suggest that pristine, laboratory-produced, nanoscale cerium oxide is not a good substitute for the cerium oxide released from fuel-borne catalyst applications and that future toxicity experiments and modeling will require the use/consideration of more realistic materials.
Fuel leak detection apparatus for gas cooled nuclear reactors
Burnette, Richard D.
1977-01-01
Apparatus is disclosed for detecting nuclear fuel leaks within nuclear power system reactors, such as high temperature gas cooled reactors. The apparatus includes a probe assembly that is inserted into the high temperature reactor coolant gaseous stream. The probe has an aperture adapted to communicate gaseous fluid between its inside and outside surfaces and also contains an inner tube for sampling gaseous fluid present near the aperture. A high pressure supply of noncontaminated gas is provided to selectively balance the pressure of the stream being sampled to prevent gas from entering the probe through the aperture. The apparatus includes valves that are operable to cause various directional flows and pressures, which valves are located outside of the reactor walls to permit maintenance work and the like to be performed without shutting down the reactor.
Solid oxide fuel cell power plant with an anode recycle loop turbocharger
Saito, Kazuo; Skiba, Tommy; Patel, Kirtikumar H.
2015-07-14
An anode exhaust recycle turbocharger (100) has a turbocharger turbine (102) secured in fluid communication with a compressed oxidant stream within an oxidant inlet line (218) downstream from a compressed oxidant supply (104), and the anode exhaust recycle turbocharger (100) also includes a turbocharger compressor (106) mechanically linked to the turbocharger turbine (102) and secured in fluid communication with a flow of anode exhaust passing through an anode exhaust recycle loop (238) of the solid oxide fuel cell power plant (200). All or a portion of compressed oxidant within an oxidant inlet line (218) drives the turbocharger turbine (102) to thereby compress the anode exhaust stream in the recycle loop (238). A high-temperature, automotive-type turbocharger (100) replaces a recycle loop blower-compressor (52).
Solid oxide fuel cell power plant with an anode recycle loop turbocharger
Saito, Kazuo; Skiba, Tommy; Patel, Kirtikumar H.
2016-09-27
An anode exhaust recycle turbocharger (100) has a turbocharger turbine (102) secured in fluid communication with a compressed oxidant stream within an oxidant inlet line (218) downstream from a compressed oxidant supply (104), and the anode exhaust recycle turbocharger (100) also includes a turbocharger compressor (106) mechanically linked to the turbocharger turbine (102) and secured in fluid communication with a flow of anode exhaust passing through an anode exhaust recycle loop (238) of the solid oxide fuel cell power plant (200). All or a portion of compressed oxidant within an oxidant inlet line (218) drives the turbocharger turbine (102) to thereby compress the anode exhaust stream in the recycle loop (238). A high-temperature, automotive-type turbocharger (100) replaces a recycle loop blower-compressor (52).
Method for enhanced atomization of liquids
Thompson, Richard E.; White, Jerome R.
1993-01-01
In a process for atomizing a slurry or liquid process stream in which a slurry or liquid is passed through a nozzle to provide a primary atomized process stream, an improvement which comprises subjecting the liquid or slurry process stream to microwave energy as the liquid or slurry process stream exits the nozzle, wherein sufficient microwave heating is provided to flash vaporize the primary atomized process stream.
Tritium Separation from High Volume Dilute Aqueous Streams- Milestone Report for M3FT-15OR0302092
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bhave, Ramesh R.; Jubin, Robert Thomas; Spencer, Barry B.
2016-02-29
This report describes the synthesis and evaluation of molecular sieve zeolite membranes to separate and concentrate tritiated water (HTO) from dilute HTO-bearing aqueous streams. Several silico alumino phosphate (SAPO-34) molecular sieve zeolite membranes were synthesized and characterized with gas and vapor permeation measurements. The pervaporation process performance was evaluated for the separation and concentration of tritiated water. Experiments were performed over a range of tritiated water concentration covering the range of concentration anticipated in nuclear fuel processing where potentially both acid and water streams are recycled. The permeate was recovered under vacuum. The tritium concentration ranged from 0.5 to 1more » mCi/mL which is about 0.1 mg/L or 0.1 ppm. The HTO concentration was three orders of magnitude lower than experiments performed with simulated feed containing HDO (>100 ppm) using deuterated water where high separation factors (>10) were obtained using SAPO membranes. Separation factor calculated from the measured tritium concentrations ranged from 0.83-0.98. Although the membrane performance characterization results were lower than expected, they can be explained on the basis of low feed volume and three orders of magnitude lower HTO concentration compared to HDO concentration in deuterated water. We have identified several new approaches, such as tuning the diffusion coefficient of HTO, that may help achieve preferential transport of tritium (HTO) resulting in a substantially more concentrated permeate.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vance, J.N.; Holderness, J.H.; James, D.W.
1992-12-01
Waste stream scaling factors based on sampling programs are vulnerable to one or more of the following factors: sample representativeness, analytic accuracy, and measurement sensitivity. As an alternative to sample analyses or as a verification of the sampling results, this project proposes the use of the RADSOURCE code, which accounts for the release of fuel-source radionuclides. Once the release rates of these nuclides from fuel are known, the code develops scaling factors for waste streams based on easily measured Cobalt-60 (Co-60) and Cesium-137 (Cs-137). The project team developed mathematical models to account for the appearance rate of 10CFR61 radionuclides inmore » reactor coolant. They based these models on the chemistry and nuclear physics of the radionuclides involved. Next, they incorporated the models into a computer code that calculates plant waste stream scaling factors based on reactor coolant gamma- isotopic data. Finally, the team performed special sampling at 17 reactors to validate the models in the RADSOURCE code.« less
Small-Scale Waste-to-Energy Technology for Contingency Bases
2012-05-24
Expedient, No Waste Sorting Technology Readiness Level High Fuel Demand Water Required Steam Infrastructure Required Air Emissions Gasification ...Full gasification system • Costs $26K • GM Industrial Engine (GM 4 Cylinder, 3.00 L) • MeccAlte Generator Head • Imbert type downdraft reactor...Solid waste volume reduction − Response to waste streams biomass , refuse-derived fuel, shredded waste − Operation and maintenance requirements
McCallister, S. Leigh; del Giorgio, Paul A.
2012-01-01
Northern rivers and lakes process large quantities of organic and inorganic carbon from the surrounding terrestrial ecosystems. These external carbon inputs fuel widespread CO2 supersaturation in continental waters, and the resulting CO2 emissions from lakes and rivers are now recognized as a globally significant loss of terrestrial production to the atmosphere. Whereas the magnitude of emissions has received much attention, the pathways of C delivery and processing that generate these emissions are still not well-understood. CO2 outgassing in aquatic systems has been unequivocally linked to microbial degradation and respiration of terrestrial organic carbon (OC), but the nature (i.e., age and source) of this OC respired in surface waters is largely unknown. We present direct radiocarbon measurements of OC respired by bacteria in freshwater aquatic systems, specifically temperate lakes and streams in Québec. Terrestrial OC fuels much of the respiration in these systems, and our results show that a significant fraction of the respired terrestrial OC is old (in the range of 1,000–3,000 y B.P.). Because the bulk OC pools in these lakes is relatively young, our results also suggest selective removal of an old but highly bioreactive terrestrial OC pool and its conversion to CO2 by bacteria. The respiration of ancient 14C-depleted terrestrial C in northern lakes and rivers provides a biological link between contemporary aquatic carbon biogeochemistry and paleo-conditions in the watershed, and it implies the aquatic-mediated return to the atmosphere of C putatively considered permanently stored, thus challenging current models of long-term C storage in terrestrial reservoirs. PMID:23027957
Bruno, Thomas J; Ott, Lisa S; Lovestead, Tara M; Huber, Marcia L
2010-04-16
The analysis of complex fluids such as crude oils, fuels, vegetable oils and mixed waste streams poses significant challenges arising primarily from the multiplicity of components, the different properties of the components (polarity, polarizability, etc.) and matrix properties. We have recently introduced an analytical strategy that simplifies many of these analyses, and provides the added potential of linking compositional information with physical property information. This aspect can be used to facilitate equation of state development for the complex fluids. In addition to chemical characterization, the approach provides the ability to calculate thermodynamic properties for such complex heterogeneous streams. The technique is based on the advanced distillation curve (ADC) metrology, which separates a complex fluid by distillation into fractions that are sampled, and for which thermodynamically consistent temperatures are measured at atmospheric pressure. The collected sample fractions can be analyzed by any method that is appropriate. The analytical methods we have applied include gas chromatography (with flame ionization, mass spectrometric and sulfur chemiluminescence detection), thin layer chromatography, FTIR, corrosivity analysis, neutron activation analysis and cold neutron prompt gamma activation analysis. By far, the most widely used analytical technique we have used with the ADC is gas chromatography. This has enabled us to study finished fuels (gasoline, diesel fuels, aviation fuels, rocket propellants), crude oils (including a crude oil made from swine manure) and waste oils streams (used automotive and transformer oils). In this special issue of the Journal of Chromatography, specifically dedicated to extraction technologies, we describe the essential features of the advanced distillation curve metrology as an analytical strategy for complex fluids. Published by Elsevier B.V.
Safety considerations in testing a fuel-rich aeropropulsion gas generator
NASA Technical Reports Server (NTRS)
Rollbuhler, R. James; Hulligan, David D.
1991-01-01
A catalyst containing reactor is being tested using a fuel-rich mixture of Jet A fuel and hot input air. The reactor product is a gaseous fuel that can be utilized in aeropropulsion gas turbine engines. Because the catalyst material is susceptible to damage from high temperature conditions, fuel-rich operating conditions are attained by introducing the fuel first into an inert gas stream in the reactor and then displacing the inert gas with reaction air. Once a desired fuel-to-air ratio is attained, only limited time is allowed for a catalyst induced reaction to occur; otherwise the inert gas is substituted for the air and the fuel flow is terminated. Because there presently is not a gas turbine combustor in which to burn the reactor product gas, the gas is combusted at the outlet of the test facility flare stack. This technique in operations has worked successfully in over 200 tests.
Advanced Optical Diagnostic Methods for Describing Fuel Injection and Combustion Flowfield Phenomena
NASA Technical Reports Server (NTRS)
Locke, Randy J.; Hicks, Yolanda R.; Anderson, Robert C.
2004-01-01
Over the past decade advanced optical diagnostic techniques have evolved and matured to a point where they are now widely applied in the interrogation of high pressure combusting flows. At NASA Glenn Research Center (GRC), imaging techniques have been used successfully in on-going work to develop the next generation of commercial aircraft gas turbine combustors. This work has centered on providing a means by which researchers and designers can obtain direct visual observation and measurements of the fuel injection/mixing/combustion processes and combustor flowfield in two- and three-dimensional views at actual operational conditions. Obtaining a thorough understanding of the chemical and physical processes at the extreme operating conditions of the next generation of combustors is critical to reducing emissions and increasing fuel efficiency. To accomplish this and other tasks, the diagnostic team at GRC has designed and constructed optically accessible, high pressurer high temperature flame tubes and sectar rigs capable of optically probing the 20-60 atm flowfields of these aero-combustors. Among the techniques employed at GRC are planar laser-induced fluorescence (PLIF) for imaging molecular species as well as liquid and gaseous fuel; planar light scattering (PLS) for imaging fuel sprays and droplets; and spontaneous Raman scattering for species and temperature measurement. Using these techniques, optical measurements never before possible have been made in the actual environments of liquid fueled gas turbines. 2-D mapping of such parameters as species (e.g. OH-, NO and kerosene-based jet fuel) distribution, injector spray angle, and fuel/air distribution are just some of the measurements that are now routinely made. Optical imaging has also provided prompt feedback to researchers regarding the effects of changes in the fuel injector configuration on both combustor performance and flowfield character. Several injector design modifications and improvements have resulted from this feedback. Alternate diagnostic methods are constantly being evaluated as to their suitability as a diagnostic tool in these environments. A new method currently under examination is background oriented Schlieren (BOS) for examining the fuel/air mixing processes. While ratioing the Stokes and anti-Stokes nitrogen lines obtained from spontaneous Raman is being refined for temperature measurement. While the primary focus of the GRC diagnostic work remains optical species measurement and flow stream characterization, an increased emphasis has been placed on our involvement in flame code validation efforts. A functional combustor code should shorten and streamline future combustor design. Quantitative measurements of flow parameters such as temperature, species concentration, drop size and velocity using such methods as Raman and phase Doppler anemometry will provide data necessary in this effort.
Activities of the Institute of Chemical Processing of Coal at Zabrze
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dreszer, K.
1995-12-31
The Institute of Chemical Processing of Coal at Zabrze was established in 1955. The works on carbochemical technologies have been, therefore, carried out at the Institute for 40 years. The targets of the Institute`s activities are research, scientific and developing works regarding a sensible utilization of fuels via their processing into more refined forms, safe environment, highly efficient use of energy carriers and technological products of special quality. The Institute of Chemical Processing of Coal has been dealing with the following: optimized use of home hard coals; improvement of classic coal coking technologies, processing and utilization of volatile coking products;more » production technologies of low emission rate fuels for communal management; analyses of coal processing technologies; new technologies aimed at increasing the efficiency of coal utilization for energy-generating purposes, especially in industry and studies on the ecological aspects of these processes; production technologies of sorbents and carbon activating agents and technologies of the utilization; rationalization of water and wastes management in the metallurgical and chemical industries in connection with removal of pollution especially dangerous to the environment from wastes; utilization technologies of refined materials (electrode cokes, binders, impregnating agents) for making electrodes, refractories and new generation construction carbon materials; production technologies of high quality bituminous and bituminous and resin coating, anti-corrosive and insulation materials; environmentally friendly utilization technologies for power station, mine and other wastes, and dedusting processes in industrial gas streams.« less
NASA Technical Reports Server (NTRS)
Mickelsen, William R
1957-01-01
Vapor fuel-oxidant mixing is analyzed for standing transverse acoustic fields simulating those existing in screeching or screaming combustors. The additional mixing due to the acoustic field is shown to be a function of sound pressure and frequency, stream velocity, and turbulence. The effects of these parameters are shown graphically for a realistic range of combustor conditions. The fuel-oxidant ratio at various combustor stations is shown to have a cyclic fluctuation which is in phase with the pressure fluctuations. Possible mechanisms contributing to screech and scream are discussed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Snowden-Swan, Lesley J.; Zhu, Yunhua; Jones, Susanne B.
A preliminary process model and techno-economic analysis (TEA) was completed for fuel produced from hydrothermal liquefaction (HTL) of sludge waste from a municipal wastewater treatment plant (WWTP) and subsequent biocrude upgrading. The model is adapted from previous work by Jones et al. (2014) for algae HTL, using experimental data generated in fiscal year 2015 (FY15) bench-scale HTL testing of sludge waste streams. Testing was performed on sludge samples received from Metro Vancouver’s Annacis Island WWTP (Vancouver, B.C.) as part of a collaborative project with the Water Environment and Reuse Foundation (WERF). The full set of sludge HTL testing data frommore » this effort will be documented in a separate report to be issued by WERF. This analysis is based on limited testing data and therefore should be considered preliminary. In addition, the testing was conducted with the goal of successful operation, and therefore does not represent an optimized process. Future refinements are necessary to improve the robustness of the model, including a cross-check of modeled biocrude components with the experimental GCMS data and investigation of equipment costs most appropriate at the relatively small scales used here. Environmental sustainability metrics analysis is also needed to understand the broader impact of this technology pathway. The base case scenario for the analysis consists of 10 HTL plants, each processing 100 dry U.S. ton/day (92.4 ton/day on a dry, ash-free basis) of sludge waste and producing 234 barrel per stream day (BPSD) biocrude, feeding into a centralized biocrude upgrading facility that produces 2,020 barrel per standard day of final fuel. This scale was chosen based upon initial wastewater treatment plant data collected by PNNL’s resource assessment team from the EPA’s Clean Watersheds Needs Survey database (EPA 2015a) and a rough estimate of what the potential sludge availability might be within a 100-mile radius. In addition, we received valuable feedback from the wastewater treatment industry as part of the WERF collaboration that helped form the basis for the selected HTL and upgrading plant scales and feedstock credit (current cost of disposal). It is assumed that the sludge is currently disposed of at $16.20/wet ton ($46/dry ton at 35% solids; $50/ton dry, ash-free basis) and this is included as a feedstock credit in the operating costs. The base case assumptions result in a minimum biocrude selling price of $3.8/gge and a minimum final upgraded fuel selling price of $4.9/gge. Several areas of process improvement and refinements to the analysis have the potential to significantly improve economics relative to the base case: •Optimization of HTL sludge feed solids content •Optimization of HTL biocrude yield •Optimization of HTL reactor liquid hourly space velocity (LHSV) •Optimization of fuel yield from hydrotreating •Combined large and small HTL scales specific to regions (e.g., metropolitan and suburban plants) Combined improvements believed to be achievable in these areas can potentially reduce the minimum selling price of biocrude and final upgraded fuel by about 50%. Further improvements may be possible through recovery of higher value components from the HTL aqueous phase, as being investigated under separate PNNL projects. Upgrading the biocrude at an existing petroleum refinery could also reduce the MFSP, although this option requires further testing to ensure compatibility and mitigation of risks to a refinery. And finally, recycling the HTL aqueous phase product stream back to the headworks of the WWTP (with no catalytic hydrothermal gasification treatment) can significantly reduce cost. This option is uniquely appropriate for application at a water treatment facility but also requires further investigation to determine any technical and economic challenges related to the extra chemical oxygen demand (COD) associated with the recycled water.« less
Anammox-based technologies for nitrogen removal: Advances in process start-up and remaining issues.
Ali, Muhammad; Okabe, Satoshi
2015-12-01
Nitrogen removal from wastewater via anaerobic ammonium oxidation (anammox)-based process has been recognized as efficient, cost-effective and low energy alternative to the conventional nitrification and denitrification processes. To date, more than one hundred full-scale anammox plants have been installed and operated for treatment of NH4(+)-rich wastewater streams around the world, and the number is increasing rapidly. Since the discovery of anammox process, extensive researches have been done to develop various anammox-based technologies. However, there are still some challenges in practical application of anammox-based treatment process at full-scale, e.g., longer start-up period, limited application to mainstream municipal wastewater and poor effluent water quality. This paper aimed to summarize recent status of application of anammox process and researches on technological development for solving these remaining problems. In addition, an integrated system of anammox-based process and microbial fuel cell is proposed for sustainable and energy-positive wastewater treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.
Apparatus for the liquefaction of natural gas and methods relating to same
Wilding, Bruce M [Idaho Falls, ID; McKellar, Michael G [Idaho Falls, ID; Turner, Terry D [Ammon, ID; Carney, Francis H [Idaho Falls, ID
2009-09-29
An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through an expander creating work output. A compressor may be driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream.
Low-Carbon Fuel and Chemical Production by Anaerobic Gas Fermentation.
Daniell, James; Nagaraju, Shilpa; Burton, Freya; Köpke, Michael; Simpson, Séan Dennis
World energy demand is expected to increase by up to 40% by 2035. Over this period, the global population is also expected to increase by a billion people. A challenge facing the global community is not only to increase the supply of fuel, but also to minimize fossil carbon emissions to safeguard the environment, at the same time as ensuring that food production and supply is not detrimentally impacted. Gas fermentation is a rapidly maturing technology which allows low carbon fuel and commodity chemical synthesis. Unlike traditional biofuel technologies, gas fermentation avoids the use of sugars, relying instead on gas streams rich in carbon monoxide and/or hydrogen and carbon dioxide as sources of carbon and energy for product synthesis by specialized bacteria collectively known as acetogens. Thus, gas fermentation enables access to a diverse array of novel, large volume, and globally available feedstocks including industrial waste gases and syngas produced, for example, via the gasification of municipal waste and biomass. Through the efforts of academic labs and early stage ventures, process scale-up challenges have been surmounted through the development of specialized bioreactors. Furthermore, tools for the genetic improvement of the acetogenic bacteria have been reported, paving the way for the production of a spectrum of ever-more valuable products via this process. As a result of these developments, interest in gas fermentation among both researchers and legislators has grown significantly in the past 5 years to the point that this approach is now considered amongst the mainstream of emerging technology solutions for near-term low-carbon fuel and chemical synthesis.
Wilding, Bruce M; Turner, Terry D
2014-12-02
A method of natural gas liquefaction may include cooling a gaseous NG process stream to form a liquid NG process stream. The method may further include directing the first tail gas stream out of a plant at a first pressure and directing a second tail gas stream out of the plant at a second pressure. An additional method of natural gas liquefaction may include separating CO.sub.2 from a liquid NG process stream and processing the CO.sub.2 to provide a CO.sub.2 product stream. Another method of natural gas liquefaction may include combining a marginal gaseous NG process stream with a secondary substantially pure NG stream to provide an improved gaseous NG process stream. Additionally, a NG liquefaction plant may include a first tail gas outlet, and at least a second tail gas outlet, the at least a second tail gas outlet separate from the first tail gas outlet.
Apparatus for the liquefaction of natural gas and methods relating to same
Wilding, Bruce M [Idaho Falls, ID; Bingham, Dennis N [Idaho Falls, ID; McKellar, Michael G [Idaho Falls, ID; Turner, Terry D [Ammon, ID; Raterman, Kevin T [Idaho Falls, ID; Palmer, Gary L [Shelley, ID; Klingler, Kerry M [Idaho Falls, ID; Vranicar, John J [Concord, CA
2007-05-22
An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating work output. A compressor is driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream. Additional features and techniques may be integrated with the liquefaction process including a water clean-up cycle and a carbon dioxide (CO.sub.2) clean-up cycle.
Apparatus For The Liquefaaction Of Natural Gas And Methods Relating To Same
Wilding, Bruce M.; Bingham, Dennis N.; McKellar, Michael G.; Turner, Terry D.; Rateman, Kevin T.; Palmer, Gary L.; Klinger, Kerry M.; Vranicar, John J.
2005-11-08
An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating work output. A compressor is driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream. Additional features and techniques may be integrated with the liquefaction process including a water clean-up cycle and a carbon dioxide (CO2) clean-up cycle.
Apparatus For The Liquefaaction Of Natural Gas And Methods Relating To Same
Wilding, Bruce M.; Bingham, Dennis N.; McKellar, Michael G.; Turner, Terry D.; Raterman, Kevin T.; Palmer, Gary L.; Klingler, Kerry M.; Vranicar, John J.
2005-05-03
An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating work output. A compressor is driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream. Additional features and techniques may be integrated with the liquefaction process including a water clean-up cycle and a carbon dioxide (CO2) clean-up cycle.
Apparatus For The Liquefaaction Of Natural Gas And Methods Relating To Same
Wilding, Bruce M.; Bingham, Dennis N.; McKellar, Michael G.; Turner, Terry D.; Raterman, Kevin T.; Palmer, Gary L.; Klingler, Kerry M.; Vranicar, John J.
2003-06-24
An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating work output. A compressor is driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream. Additional features and techniques may be integrated with the liquefaction process including a water clean-up cycle and a carbon dioxide (CO.sub.2) clean-up cycle.
NASA Astrophysics Data System (ADS)
Aufiero, M.; Cammi, A.; Fiorina, C.; Leppänen, J.; Luzzi, L.; Ricotti, M. E.
2013-10-01
In this work, the Monte Carlo burn-up code SERPENT-2 has been extended and employed to study the material isotopic evolution of the Molten Salt Fast Reactor (MSFR). This promising GEN-IV nuclear reactor concept features peculiar characteristics such as the on-line fuel reprocessing, which prevents the use of commonly available burn-up codes. Besides, the presence of circulating nuclear fuel and radioactive streams from the core to the reprocessing plant requires a precise knowledge of the fuel isotopic composition during the plant operation. The developed extension of SERPENT-2 directly takes into account the effects of on-line fuel reprocessing on burn-up calculations and features a reactivity control algorithm. It is here assessed against a dedicated version of the deterministic ERANOS-based EQL3D procedure (PSI-Switzerland) and adopted to analyze the MSFR fuel salt isotopic evolution. Particular attention is devoted to study the effects of reprocessing time constants and efficiencies on the conversion ratio and the molar concentration of elements relevant for solubility issues (e.g., trivalent actinides and lanthanides). Quantities of interest for fuel handling and safety issues are investigated, including decay heat and activities of hazardous isotopes (neutron and high energy gamma emitters) in the core and in the reprocessing stream. The radiotoxicity generation is also analyzed for the MSFR nominal conditions. The production of helium and the depletion in tungsten content due to nuclear reactions are calculated for the nickel-based alloy selected as reactor structural material of the MSFR. These preliminary evaluations can be helpful in studying the radiation damage of both the primary salt container and the axial reflectors.
Weathering Patterns of Ignitable Liquids with the Advanced Distillation Curve Method
Bruno, Thomas J; Allen, Samuel
2013-01-01
One can take advantage of the striking similarity of ignitable liquid vaporization (or weathering) patterns and the separation observed during distillation to predict the composition of residual compounds in fire debris. This is done with the advanced distillation curve (ADC) metrology, which separates a complex fluid by distillation into fractions that are sampled, and for which thermodynamically consistent temperatures are measured at atmospheric pressure. The collected sample fractions can be analyzed by any method that is appropriate. Analytical methods we have applied include gas chromatography (with flame ionization, mass spectrometric and sulfur chemiluminescence detection), thin layer chromatography, FTIR, Karl Fischer coulombic titrimetry, refractometry, corrosivity analysis, neutron activation analysis and cold neutron prompt gamma activation analysis. We have applied this method on product streams such as finished fuels (gasoline, diesel fuels, aviation fuels, rocket propellants), crude oils (including a crude oil made from swine manure) and waste oils streams (used automotive and transformer oils). In this paper, we present results on a variety of ignitable liquids that are not commodity fuels, chosen from the Ignitable Liquids Reference Collection (ILRC). These measurements are assembled into a preliminary database. From this selection, we discuss the significance and forensic application of the temperature data grid and the composition explicit data channel of the ADC. PMID:26401423
Weathering Patterns of Ignitable Liquids with the Advanced Distillation Curve Method.
Bruno, Thomas J; Allen, Samuel
2013-01-01
One can take advantage of the striking similarity of ignitable liquid vaporization (or weathering) patterns and the separation observed during distillation to predict the composition of residual compounds in fire debris. This is done with the advanced distillation curve (ADC) metrology, which separates a complex fluid by distillation into fractions that are sampled, and for which thermodynamically consistent temperatures are measured at atmospheric pressure. The collected sample fractions can be analyzed by any method that is appropriate. Analytical methods we have applied include gas chromatography (with flame ionization, mass spectrometric and sulfur chemiluminescence detection), thin layer chromatography, FTIR, Karl Fischer coulombic titrimetry, refractometry, corrosivity analysis, neutron activation analysis and cold neutron prompt gamma activation analysis. We have applied this method on product streams such as finished fuels (gasoline, diesel fuels, aviation fuels, rocket propellants), crude oils (including a crude oil made from swine manure) and waste oils streams (used automotive and transformer oils). In this paper, we present results on a variety of ignitable liquids that are not commodity fuels, chosen from the Ignitable Liquids Reference Collection (ILRC). These measurements are assembled into a preliminary database. From this selection, we discuss the significance and forensic application of the temperature data grid and the composition explicit data channel of the ADC.
Prioritized Contact Transport Stream
NASA Technical Reports Server (NTRS)
Hunt, Walter Lee, Jr. (Inventor)
2015-01-01
A detection process, contact recognition process, classification process, and identification process are applied to raw sensor data to produce an identified contact record set containing one or more identified contact records. A prioritization process is applied to the identified contact record set to assign a contact priority to each contact record in the identified contact record set. Data are removed from the contact records in the identified contact record set based on the contact priorities assigned to those contact records. A first contact stream is produced from the resulting contact records. The first contact stream is streamed in a contact transport stream. The contact transport stream may include and stream additional contact streams. The contact transport stream may be varied dynamically over time based on parameters such as available bandwidth, contact priority, presence/absence of contacts, system state, and configuration parameters.
Shock tunnel studies of scramjet phenomena, supplement 8
NASA Technical Reports Server (NTRS)
Stalker, R. J.; Hollis, P.; Allen, G. A.; Roberts, G. T.; Tuttle, S.; Bakos, R. J.; Morgan, R. G.; Pulsonetti, M. V.; Brescianini, C.; Buttsworth, D. R.
1993-01-01
Reports by the staff of the University of Oueensland on various research studies related to the advancement of scramjet technology are presented. These reports document the tests conducted in the reflected shock tunnel T4 and supporting research facilities that have been used to study the injection, mixing, and combustion of hydrogen fuel in generic scramjets at flow conditions typical of hypersonic flight. In addition, topics include the development of instrumentation and measurement technology, such as combustor wall shear and stream composition in pulse facilities, and numerical studies and analyses of the scramjet combustor process and the test facility operation. This research activity is Supplement 8 under NASA Grant NAGW-674.
Shock tunnel studies of scramjet phenomena, supplement 7
NASA Technical Reports Server (NTRS)
Bakos, R. J.; Morgan, R. G.; Tuttle, S. L.; Kelly, G. M.; Paull, A.; Simmons, J. M.; Stalker, R. J.; Pulsonetti, M. V.; Buttsworth, D.; Allen, G. A., Jr.
1993-01-01
Reports by the staff of the University of Queensland on various research studies related to the advancement of scramjet technology are presented. These reports document the tests conducted in the reflected shock tunnel T4 and supporting research facilities that have been used to study the injection, mixing, and combustion of hydrogen fuel in generic scramjets at flow conditions typical of hypersonic flight. In addition, topics include the development of instrumentation and measurement technology, such as combustor wall shear and stream composition in pulse facilities, and numerical studies and analyses of the scramjet combustor process and the test facility operation. This research activity is Supplement 7 under NASA Grant NAGW-674.
Method And Apparatus For Converting Hydrocarbon Fuel Into Hydrogen Gas And Carbon Dioxide
Clawson, Lawrence G.; Mitchell, William L.; Bentley, Jeffrey M.; Thijssen, Johannes H. J.
2001-03-27
A hydrocarbon fuel reforming method is disclosed suitable for producing synthesis hydrogen gas from reactions with hydrocarbons fuels, oxygen, and steam. A first mixture of an oxygen-containing gas and a first fuel is directed into a first tube 108 to produce a first reaction reformate. A second mixture of steam and a second fuel is directed into a second tube 116 annularly disposed about the first tube 108 to produce a second reaction reformate. The first and second reaction reformates are then directed into a reforming zone 144 and subject to a catalytic reforming reaction. In another aspect of the method, a first fuel is combusted with an oxygen-containing gas in a first zone 108 to produce a reformate stream, while a second fuel under steam reforming in a second zone 116. Heat energy from the first zone 108 is transferred to the second zone 116.
Intelligent Engine Systems: Alternate Fuels Evaluation
NASA Technical Reports Server (NTRS)
Ballal, Dilip
2008-01-01
The performance and gaseous emissions were measured for a well-stirred reactor operating under lean conditions for two fuels: JP8 and a synthetic Fisher-Tropsch fuel over a range of equivalence ratios from 0.6 down to the lean blowout. The lean blowout characteristics were determined in LBO experiments at loading parameter values from 0.7 to 1.4. The lean blowout characteristics were then explored under higher loading conditions by simulating higher altitude operation with the use of nitrogen as a dilution gas for the air stream. The experiments showed that: (1) The lean blowout characteristics for the two fuels were close under both low loading and high loading conditions. (2) The combustion temperatures and observed combustion efficiencies were similar for the two fuels. (3) The gaseous emissions were similar for the two fuels and the differences in the H2O and CO2 emissions appear to be directly relatable to the C/H ratio for the fuels.
Peters, N.E.; Cerny, J.; Havel, M.; Krejci, R.
1999-01-01
The Krusne hory (Erzgebirge or Ore Mountains) has been heavily affected by high atmospheric pollutant deposition caused by fossil fuel combustion in an adjacent Tertiary coal basin. Long-term routine sampling of bulk precipitation (1977-1996) and stream water (1977-1998) in a forested area on the south-eastern slope of the mountains were used to evaluate trends and patterns in solute concentration and flux with respect to controlling processes. From 1977 to 1996, the annual volume-weighted Ca2+ and SO42- concentrations decreased in bulk precipitation. However, after 1989, when a pronounced and continuous decrease occurred in coal production, annual volume-weighted concentrations decreased for most solutes, except H+. The concentration decreases were marked, with 1996 levels at or below 50% of those in 1989. The lack of a trend in H+ is attributed to similar decreases in both acid anions and neutralizing base cations. Stream water concentrations of most solutes, i.e. H+, Ca2+, Mg2+, SO42- and NO3-, were highest at the onset of sampling in 1977, decreased markedly from 1977 to 1983 and decreased more gradually from 1983 to 1998. The spruce forest die-back and removal reduced dry deposition of these solutes by reducing the filtering action, which was provided by the forest canopy. A notable decrease in stream water Ca2+ concentrations occurred after 1995 and may be due to the depletion of Ca2+, which was provided by catchment liming in 1986, 1988 and 1989. Solute flux trends in bulk atmospheric deposition and stream water generally were not significant and the lack of trend is attributed to the large interannual variability in precipitation quantity and runoff, respectively. All solutes except Na+ varied seasonally. The average seasonal concentrations varied between the solutes, but for most solutes were highest in winter and spring and lowest in summer, correlating with the seasonal trend and runoff. For Ca2+, Mg2+ and SO42-, the concentration minimum occurs in September and the maximum occurs in February or March, correlating with the seasonal baseflow. These solutes are primarily controlled by the contribution of soil water and groundwater to stream flow. During snowmelt, the meltwater generally causes concentrations to decrease as soil water and groundwater are diluted. For NO3, average minimum concentrations occur in August at the end of the growing season concurrent with the lowest stream flow, and the maximum occurs in February and March with high stream flow during snowmelt. Seasonal stream water NO3- concentration variations are large compared with the long-term decrease.The Krusne hory (Erzgebirge or Ore Mountains) has been heavily affected by high atmospheric pollutant deposition caused by fossil fuel combustion in an adjacent Tertiary coal basin. Long-term routine sampling of bulk precipitation (1977-1996) and stream water (1977-1998) in a forested area on the south-eastern slope of the mountains were used to evaluate trends and patterns in solute concentration and flux with respect to controlling processes. From 1977 to 1996, the annual volume-weighted Ca2+ and SO42- concentrations decreased in bulk precipitation. However, after 1989, when a pronounced and continuous decrease occurred in coal production, annual volume-weighted concentrations decreased for most solutes, except H+. The concentration decreases were marked, with 1996 levels at or below 50% of those in 1989. The lack of a trend in H+ is attributed to similar decreases in both acid anions and neutralizing base cations. Stream water concentrations of most solutes, i.e. H+, Ca2+, Mg2+, SO42- and NO3-, were highest at the onset of sampling in 1977, decreased markedly from 1977 to 1983 and decreased more gradually from 1983 to 1998. The spruce forest die-back and removal reduced dry deposition of these solutes by reducing the filtering action, which was provided by the forest canopy. A notable decrease in stream water Ca2+ concentrations occurred after 1995 an
Final report of fuel dynamics Test E7
DOE Office of Scientific and Technical Information (OSTI.GOV)
Doerner, R.C.; Murphy, W.F.; Stanford, G.S.
1977-04-01
Test data from an in-pile failure experiment of high-power LMFBR-type fuel pins in a simulated $3/s transient-overpower (TOP) accident are reported and analyzed. Major conclusions are that (1) a series of cladding ruptures during the 100-ms period preceding fuel release injected small bursts of fission gas into the flow stream; (2) gas release influenced subsequent cladding melting and fuel release (there were no measurable FCI's (fuel-coolant interactions), and all fuel motion observed by the hodoscope was very slow); (3) the predominant postfailure fuel motion appears to be radial swelling that left a spongy fuel crust on the holder wall; (4)more » less than 4 to 6 percent of the fuel moved axially out of the original fuel zone, and most of this froze within a 10-cm region above the original top of the fuel zone to form the outlet blockage. An inlet blockage approximately 1 cm long was formed and consisted of large interconnected void regions. Both blockages began just beyond the ends of the fuel pellets.« less
Quantitative characterization of the aqueous fraction from hydrothermal liquefaction of algae
DOE Office of Scientific and Technical Information (OSTI.GOV)
Maddi, Balakrishna; Panisko, Ellen; Wietsma, Thomas
Aqueous streams generated from hydrothermal liquefaction contain approximately 30% of the total carbon present from the algal feed. Hence, this aqueous carbon must be utilized to produce liquid fuels and/or specialty chemicals for economic sustainability of hydrothermal liquefaction on industrial scale. In this study, aqueous fractions produced from the hydrothermal liquefaction of fresh water and saline water algal cultures were analyzed using a wide variety of analytical instruments to determine their compositional characteristics. This study will also inform researchers designing catalysts for down-stream processing such as high-pressure catalytic conversion of organics in aqueous phase, catalytic hydrothermal gasification, and biological conversions.more » Organic chemical compounds present in all eight aqueous fractions were identified using two-dimensional gas chromatography equipped with time-of-flight mass spectrometry. Identified compounds include organic acids, nitrogen compounds and aldehydes/ketones. Conventional gas chromatography and liquid chromatography methods were utilized to quantify the identified compounds. Inorganic species in the aqueous stream of hydrothermal liquefaction of algae were identified using ion chromatography and inductively coupled plasma optical emission spectrometer. The concentrations of organic chemical compounds and inorganic species are reported. The amount quantified carbon ranged from 45 to 72 % of total carbon in the aqueous fractions.« less
Photographic combustion characterization of LOX/Hydrocarbon type propellants
NASA Technical Reports Server (NTRS)
Judd, D. C.
1980-01-01
One hundred twenty-seven tests were conducted over a chamber pressure range of 125-1500 psia, a fuel temperature range of -245 F to 158 F, and a fuel velocity range of 48-707 ft/sec to demonstrate the advantages and limitations of using high speed photography to identify potential combustion anomalies such as pops, fuel freezing, reactive stream separation and carbon formations. Combustion evaluation criteria were developed to guide selection of the fuels, injector elements, and operating conditions for testing. Separate criteria were developed for fuel and injector element selection and evaluation. The photographic test results indicated conclusively that injector element type and design directly influence carbon formation. Unlike spray fan, impingement elements reduce carbon formation because they induce a relatively rapid near zone fuel vaporization rate. Coherent jet impingement elements, on the other hand, exhibit increased carbon formation.
Thermal acidization and recovery process for recovering viscous petroleum
Poston, Robert S.
1984-01-01
A thermal acidization and recovery process for increasing production of heavy viscous petroleum crude oil and synthetic fuels from subterranean hydrocarbon formations containing clay particles creating adverse permeability effects is described. The method comprises injecting a thermal vapor stream through a well bore penetrating such formations to clean the formation face of hydrocarbonaceous materials which restrict the flow of fluids into the petroleum-bearing formation. Vaporized hydrogen chloride is then injected simultaneously to react with calcium and magnesium salts in the formation surrounding the bore hole to form water soluble chloride salts. Vaporized hydrogen fluoride is then injected simultaneously with its thermal vapor to dissolve water-sensitive clay particles thus increasing permeability. Thereafter, the thermal vapors are injected until the formation is sufficiently heated to permit increased recovery rates of the petroleum.
Feature integration and object representations along the dorsal stream visual hierarchy
Perry, Carolyn Jeane; Fallah, Mazyar
2014-01-01
The visual system is split into two processing streams: a ventral stream that receives color and form information and a dorsal stream that receives motion information. Each stream processes that information hierarchically, with each stage building upon the previous. In the ventral stream this leads to the formation of object representations that ultimately allow for object recognition regardless of changes in the surrounding environment. In the dorsal stream, this hierarchical processing has classically been thought to lead to the computation of complex motion in three dimensions. However, there is evidence to suggest that there is integration of both dorsal and ventral stream information into motion computation processes, giving rise to intermediate object representations, which facilitate object selection and decision making mechanisms in the dorsal stream. First we review the hierarchical processing of motion along the dorsal stream and the building up of object representations along the ventral stream. Then we discuss recent work on the integration of ventral and dorsal stream features that lead to intermediate object representations in the dorsal stream. Finally we propose a framework describing how and at what stage different features are integrated into dorsal visual stream object representations. Determining the integration of features along the dorsal stream is necessary to understand not only how the dorsal stream builds up an object representation but also which computations are performed on object representations instead of local features. PMID:25140147
NASA Astrophysics Data System (ADS)
Schein, Perry; Erickson, David
2017-03-01
In combustion, hydrocarbon fuels are burned with oxygen to release energy, carbon dioxide and water vapor. Here, we introduce a photocatalytic reactor for reversing this process, when carbon dioxide and water are combined and using optical and thermal energy from the sun hydrocarbons are produced and oxygen is released. This allows for the sustainable production of hydrocarbon products from non-fossil sources, allowing for the development of "green" hydrocarbon products. Our reactors take the form of modular cells of 10 x 10 x 10 cm scale where light is delivered to nanostructured catalysts through the evanescent field around dielectric slab waveguides. The light distribution is optimized through the use of engineered scattering sites to enhance field uniformity. This is combined with integrated fluidic architecture to deliver a stream rich in water and carbon dioxide (such as exhaust from a natural gas burning plant) to the nanostructured catalyst particles in a narrow channel. Exhaust streams rich in oxygen and hydrocarbon products are collected at the outlet of the reactor cell. The cell is heated using solar thermal energy and temperatures of up to 200°C are achieved, enhancing reaction efficiency. Hydrocarbon products produced include methanol as well as other potentially useful molecules for fuel production or precursors to the manufacture of plastics. These reactors can be coupled to solar collectors to take advantage of the sun as a free source of heat and light, and the modular nature of the cells enables scaling to larger deployments.
Velis, Costas; Wagland, Stuart; Longhurst, Phil; Robson, Bryce; Sinfield, Keith; Wise, Stephen; Pollard, Simon
2012-02-07
Solid recovered fuel (SRF) produced by mechanical-biological treatment (MBT) of municipal waste can replace fossil fuels, being a CO(2)-neutral, affordable, and alternative energy source. SRF application is limited by low confidence in quality. We present results for key SRF properties centered on the issue of chlorine content. A detailed investigation involved sampling, statistical analysis, reconstruction of composition, and modeling of SRF properties. The total chlorine median for a typical plant during summer operation was 0.69% w/w(d), with lower/upper 95% confidence intervals of 0.60% w/w(d) and 0.74% w/w(d) (class 3 of CEN Cl indicator). The average total chlorine can be simulated, using a reconciled SRF composition before shredding to <40 mm. The relative plastics vs paper mass ratios in particular result in an SRF with a 95% upper confidence limit for ash content marginally below the 20% w/w(d) deemed suitable for certain power plants; and a lower 95% confidence limit of net calorific value (NCV) at 14.5 MJ kg(ar)(-1). The data provide, for the first time, a high level of confidence on the effects of SRF composition on its chlorine content, illustrating interrelationships with other fuel properties. The findings presented here allow rational debate on achievable vs desirable MBT-derived SRF quality, informing the development of realistic SRF quality specifications, through modeling exercises, needed for effective thermal recovery.
Barringer, Julia L.; Mumford, Adam; Young, Lily Y.; Reilly, Pamela A.; Bonin, Jennifer L.; Rosman, Robert
2010-01-01
The Cretaceous and Tertiary sediments that underlie the Inner Coastal Plain of New Jersey contain the arsenic-rich mineral glauconite. Streambed sediments in two Inner Coastal Plain streams (Crosswicks and Raccoon Creeks) that traverse these glauconitic deposits are enriched in arsenic (15–25 mg/kg), and groundwater discharging to the streams contains elevated levels of arsenic (>80 μg/L at a site on Crosswicks Creek) with arsenite generally the dominant species. Low dissolved oxygen, low or undetectable levels of nitrate and sulfate, detectable sulfide concentrations, and high concentrations of iron and dissolved organic carbon (DOC) in the groundwater indicate that reducing environments are present beneath the streambeds and that microbial activity, fueled by the DOC, is involved in releasing arsenic and iron from the geologic materials. In groundwater with the highest arsenic concentrations at Crosswicks Creek, arsenic respiratory reductase gene (arrA) indicated the presence of arsenic-reducing microbes. From extracted DNA, 16s rRNA gene sequences indicate the microbial community may include arsenic-reducing bacteria that have not yet been described. Once in the stream, iron is oxidized and precipitates as hydroxide coatings on the sediments. Arsenite also is oxidized and co-precipitates with or is sorbed to the iron hydroxides. Consequently, dissolved arsenic concentrations are lower in streamwater than in the groundwater, but the arsenic contributed by groundwater becomes part of the arsenic load in the stream when sediments are suspended during high flow. A strong positive relation between concentrations of arsenic and DOC in the groundwater samples indicates that any process—natural or anthropogenic—that increases the organic carbon concentration in the groundwater could stimulate microbial activity and thus increase the amount of arsenic that is released from the geologic materials.
Viscosity Meaurement Technique for Metal Fuels
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ban, Heng; Kennedy, Rory
2015-02-09
Metallic fuels have exceptional transient behavior, excellent thermal conductivity, and a more straightforward reprocessing path, which does not separate out pure plutonium from the process stream. Fabrication of fuel containing minor actinides and rare earth (RE) elements for irradiation tests, for instance, U-20Pu-3Am-2Np-1.0RE-15Zr samples at the Idaho National Laboratory, is generally done by melt casting in an inert atmosphere. For the design of a casting system and further scale up development, computational modeling of the casting process is needed to provide information on melt flow and solidification for process optimization. Therefore, there is a need for melt viscosity data, themore » most important melt property that controls the melt flow. The goal of the project was to develop a measurement technique that uses fully sealed melt sample with no Americium vapor loss to determine the viscosity of metallic melts and at temperatures relevant to the casting process. The specific objectives of the project were to: develop mathematical models to establish the principle of the measurement method, design and build a viscosity measurement prototype system based on the established principle, and calibrate the system and quantify the uncertainty range. The result of the project indicates that the oscillation cup technique is applicable for melt viscosity measurement. Detailed mathematical models of innovative sample ampoule designs were developed to not only determine melt viscosity, but also melt density under certain designs. Measurement uncertainties were analyzed and quantified. The result of this project can be used as the initial step toward the eventual goal of establishing a viscosity measurement system for radioactive melts.« less
Tan, Eric C. D.; Talmadge, Michael; Dutta, Abhijit; ...
2015-10-28
This paper describes in detail one potential conversion process for the production of high-octane gasoline blendstock via indirect liquefaction of biomass. The processing steps of this pathway include the conversion of biomass to synthesis gas via indirect gasification, gas clean-up via reforming of tars and other hydrocarbons, catalytic conversion of syngas to methanol, methanol dehydration to dimethyl ether (DME), and the homologation of DME over a zeolite catalyst to high-octane gasoline-range hydrocarbon products. The current process configuration has similarities to conventional methanol-to-gasoline (MTG) technologies, but there are key distinctions, specifically regarding the product slate, catalysts, and reactor conditions. A techno-economicmore » analysis is performed to investigate the production of high-octane gasoline blendstock. The design features a processing daily capacity of 2000 tonnes (2205 short tons) of dry biomass. The process yields 271 liters of liquid fuel per dry tonne of biomass (65 gal/dry ton), for an annual fuel production rate of 178 million liters (47 MM gal) at 90% on-stream time. The estimated total capital investment for an nth-plant is $438 million. The resulting minimum fuel selling price (MFSP) is $0.86 per liter or $3.25 per gallon in 2011 US dollars. A rigorous sensitivity analysis captures uncertainties in costs and plant performance. Sustainability metrics for the conversion process are quantified and assessed. The potential premium value of the high-octane gasoline blendstock is examined and found to be at least as competitive as fossil-derived blendstocks. A simple blending strategy is proposed to demonstrate the potential for blending the biomass-derived blendstock with petroleum-derived intermediates. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.« less
Removal of hydrogen sulfide from hot fuel gas using an electrochemical membrane system
NASA Astrophysics Data System (ADS)
Burke, Adrian Alan
Sulfur is a natural contaminant in nearly all fossil fuel supplies. When a fuel stream is gasified or reformed, the sulfur manifests itself in the form of hydrogen sulfide, H2S. Extraordinary effort is put forth to remove H2S to at least ppm levels before the fuel can be used for power generation. To compete with current methods, an electrochemical membrane system (EMS) is now being studied to remove H2S in one step at high temperature. This process offers continuous H2S removal at an estimated operating cost of $0.32/kg H2S removed and a capital cost that is roughly half that of a Claus plant with tail-gas clean-up. Other advantages are the considerable savings in energy and space compared to current methods. A bench scale set-up was constructed to test the cell performance at 600-700°C and 1 atm. The typical fuel stream inlet proportions were 34% CO, 22% CO2, 35% H2, 8% H2O, and 450-2000 ppm H2S. The fundamental transport restrictions for sulfur species in an electrochemical cell were examined. Temperature and membrane thickness were varied to examine how these parameters affect the maximum flux of H 2S removal. It was found that higher temperature allows more sulfide species to enter the electrolyte, thus increasing the sulfide flux across the membrane and raising the maximum flux of H2S removal. Also, membrane thickness was found to be a critical parameter in cell design. A thinner membrane decreases the distance that sulfide ions must travel to be oxidized at the anode. These results identify sulfide diffusion across the membrane as the rate-limiting step in H2S removal. The maximum H2S removal flux of 1.1 x 10-6 gmol H2S min-1 cm-2 (or 3.5 mA cm-2) was obtained at 650°C, with a membrane that was 0.9 mm thick, 36% porous, and had an estimated tortuosity of 3.6. Another focus of this thesis was to examine the stability of cathode materials in full cell trials. A major hurdle that remains in process scale-up is cathode selection, as the lifetime of the cell will depend heavily on the lifetime of the cathode material, which is exposed to very sour gas. Materials that showed success in the past (i.e cobalt sulfides and Y0.9Ca 0.1FeO3) were examined but were seen to have limitations in operating environment and temperature. Therefore, other novel metal oxide compounds were studied to find possible candidates for full cell trials. Gd2TiMoO7 and La0.7Sr0.3VO 3 were the compounds that retained their structure best even when exposed to high H2S, CO2, and H2O concentrations. They also showed no sign of melting at operating temperatures. But Gd 2TiMoO7 was seen to have better stability with electrolyte present, whereas La0.7Sr0.3VO3 was seen to have better stability in the pure sour gas stream without electrolyte present. A layered electrode that could help preserve a stable environment for each of these compounds should be explored in future research.
Water outlet control mechanism for fuel cell system operation in variable gravity environments
NASA Technical Reports Server (NTRS)
Vasquez, Arturo (Inventor); McCurdy, Kerri L. (Inventor); Bradley, Karla F. (Inventor)
2007-01-01
A self-regulated water separator provides centrifugal separation of fuel cell product water from oxidant gas. The system uses the flow energy of the fuel cell's two-phase water and oxidant flow stream and a regulated ejector or other reactant circulation pump providing the two-phase fluid flow. The system further uses a means of controlling the water outlet flow rate away from the water separator that uses both the ejector's or reactant pump's supply pressure and a compressibility sensor to provide overall control of separated water flow either back to the separator or away from the separator.
Device for staged carbon monoxide oxidation
Vanderborgh, Nicholas E.; Nguyen, Trung V.; Guante, Jr., Joseph
1993-01-01
A method and apparatus for selectively oxidizing carbon monoxide in a hydrogen rich feed stream. The method comprises mixing a feed stream consisting essentially of hydrogen, carbon dioxide, water and carbon monoxide with a first predetermined quantity of oxygen (air). The temperature of the mixed feed/oxygen stream is adjusted in a first the heat exchanger assembly (20) to a first temperature. The mixed feed/oxygen stream is sent to reaction chambers (30,32) having an oxidation catalyst contained therein. The carbon monoxide of the feed stream preferentially absorbs on the catalyst at the first temperature to react with the oxygen in the chambers (30,32) with minimal simultaneous reaction of the hydrogen to form an intermediate hydrogen rich process stream having a lower carbon monoxide content than the feed stream. The elevated outlet temperature of the process stream is carefully controlled in a second heat exchanger assembly (42) to a second temperature above the first temperature. The process stream is then mixed with a second predetermined quantity of oxygen (air). The carbon monoxide of the process stream preferentially reacts with the second quantity of oxygen in a second stage reaction chamber (56) with minimal simultaneous reaction of the hydrogen in the process stream. The reaction produces a hydrogen rich product stream having a lower carbon monoxide content than the process stream. The product stream is then cooled in a third heat exchanger assembly (72) to a third predetermined temperature. Three or more stages may be desirable, each with metered oxygen injection.
Investigations for the Recycle of Pyroprocessed Uranium
NASA Astrophysics Data System (ADS)
Westphal, B. R.; Price, J. C.; Chambers, E. E.; Patterson, M. N.
Given the renewed interest in uranium from the pyroprocessing of used nuclear fuel in a molten salt system, the two biggest hurdles for marketing the uranium are radiation levels and transuranic content. A radiation level as low as possible is desired so that handling operations can be performed directly with the uranium. The transuranic content of the uranium will affect the subsequent waste streams generated and, thus also should be minimized. Although the pyroprocessing technology was originally developed without regard to radiation and transuranic levels, adaptations to the process have been considered. Process conditions have been varied during the distillation and casting cycles of the process with increasing temperature showing the largest effect on the reduction of radiation levels. Transuranic levels can be reduced significantly by incorporating a pre-step in the salt distillation operation to remove a majority of the salt prior to distillation.
Modules for estimating solid waste from fossil-fuel technologies
DOE Office of Scientific and Technical Information (OSTI.GOV)
Crowther, M.A.; Thode, H.C. Jr.; Morris, S.C.
1980-10-01
Solid waste has become a subject of increasing concern to energy industries for several reasons. Increasingly stringent air and water pollution regulations result in a larger fraction of residuals in the form of solid wastes. Control technologies, particularly flue gas desulfurization, can multiply the amount of waste. With the renewed emphasis on coal utilization and the likelihood of oil shale development, increased amounts of solid waste will be produced. In the past, solid waste residuals used for environmental assessment have tended only to include total quantities generated. To look at environmental impacts, however, data on the composition of the solidmore » wastes are required. Computer modules for calculating the quantities and composition of solid waste from major fossil fuel technologies were therefore developed and are described in this report. Six modules have been produced covering physical coal cleaning, conventional coal combustion with flue gas desulfurization, atmospheric fluidized-bed combustion, coal gasification using the Lurgi process, coal liquefaction using the SRC-II process, and oil shale retorting. Total quantities of each solid waste stream are computed together with the major components and a number of trace elements and radionuclides.« less
Bleaching and Hydroprocessing of Algal Biomass-Derived Lipids to Produce Renewable Diesel Fuel
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kruger, Jacob S.; Christensen, Earl D.; Dong, Tao
Algal lipids represent a promising feedstock for production of renewable diesel, but there is little information available regarding the integration of pretreatment, extraction, and catalytic upgrading steps. In this work, we examined oil bleaching by two methods and the effects of bleaching on oil deoxygenation over Pd/C and hydroisomerization over Pt/SAPO-11 catalysts. The raw oil was completely deoxygenated and 90% denitrogenated after dilution to 25 wt % in hexanes. The bleaching operations (using either a polar adsorbent or concentrated H 3PO 4) removed 85-90% of the nitrogen and led to 95-99% nitrogen removal after deoxygenation. Oil processability was also improvedmore » by bleaching. Here, the bulk chemistry of the deoxygenation and isomerization was not strongly affected by bleaching, as post-isomerization products with cloud points less than -10 °C and boiling ranges within or close to specification for No. 2 diesel fuel were obtained through 10 h time on stream with or without bleaching.« less
Alginate-Encapsulated Bacteria for the Treatment of Hypersaline Solutions in Microbial Fuel Cells.
Alkotaini, Bassam; Tinucci, Samantha L; Robertson, Stuart J; Hasan, Kamrul; Minteer, Shelley D; Grattieri, Matteo
2018-04-27
A microbial fuel cell (MFC) based on a new wild-type strain of Salinivibrio sp. allowed the self-sustained treatment of hypersaline solutions (100 g L -1 , 1.71 m NaCl), reaching a removal of (87±11) % of the initial chemical oxygen demand after five days of operation, being the highest value achieved for hypersaline MFC. The degradation process and the evolution of the open circuit potential of the MFCs were correlated, opening the possibility for online monitoring of the treatment. The use of alginate capsules to trap bacterial cells, increasing cell density and stability, resulted in an eightfold higher power output, together with a more stable system, allowing operation up to five months with no maintenance required. The reported results are of critical importance to efforts to develop a sustainable and cost-effective system that treats hypersaline waste streams and reduces the quantity of polluting compounds released. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
NASA Astrophysics Data System (ADS)
Baker, M. P.; King, J. C.; Gorman, B. P.; Braley, J. C.
2015-03-01
Current methods of TRISO fuel kernel production in the United States use a sol-gel process with trichloroethylene (TCE) as the forming fluid. After contact with radioactive materials, the spent TCE becomes a mixed hazardous waste, and high costs are associated with its recycling or disposal. Reducing or eliminating this mixed waste stream would not only benefit the environment, but would also enhance the economics of kernel production. Previous research yielded three candidates for testing as alternatives to TCE: 1-bromotetradecane, 1-chlorooctadecane, and 1-iodododecane. This study considers the production of yttria-stabilized zirconia (YSZ) kernels in silicone oil and the three chosen alternative formation fluids, with subsequent characterization of the produced kernels and used forming fluid. Kernels formed in silicone oil and bromotetradecane were comparable to those produced by previous kernel production efforts, while those produced in chlorooctadecane and iodododecane experienced gelation issues leading to poor kernel formation and geometry.
Approach to Modeling Boundary Layer Ingestion Using a Fully Coupled Propulsion-RANS Model
NASA Technical Reports Server (NTRS)
Gray, Justin; Mader, Charles A.; Kenway, Gaetan K. W.; Martins, Joaquim R. R. A.
2017-01-01
Although boundary layer ingestion (BLI), or wake ingestion, is commonly applied in marine propulsion applications, it has not yet seen wide-spread adoption in aircraft applications. However, recent studies have predicted that BLI offers a potential for a 10 reduction in aircraft fuel burn, even on a fairly traditional aircraft configuration. This dramatic reduction in fuel burn is achieved via tight integration of the propulsion system and airframe aerodynamics, but actually realizing such large performance gains will require modifying the aircraft design process to account for this integration. Traditionally, in aircraft design, the airframe and the propulsion system are designed separately and then the engine sizing is managed with a rubber-engine approach. This works when the propulsion system is placed in the free-stream air, away from the aerodynamic influence of the airframe, and it is reasonable to assume that small changes to either system won't have a strong impact on the other.
The structure of dilute combusting sprays
NASA Technical Reports Server (NTRS)
Shuen, J. S.; Solomon, A. S. P.; Faeth, F. M.
1985-01-01
An experimental and theoretical study of drop processes in a turbulent flame is described. The experiments involved a monodisperse (105 and 180 micro m initial diameter) stream of methanol drops injected at the base of a turbulent methane-fueled diffusion flame burning in still air. The following measurements were made: mean and fluctuating phase velocities, mean drop number flux, drop-size distributions and mean gas-phase temperatures. Measurements were compared with predictions of two separated flow models: (1) deterministic separated flow, where drop-turbulence interactions are ignored; and (2) stochastic separated flow, where drop-turbulence interactions are considered using random-walk computations. The stochastic separated flow analysis yielded best agreement with measurements, since it provides for turbulent dispersion of drops which was important for present test conditions (and probably for most combusting sprays as well). Distinguishing the presence or absence of envelope flames around the drops, however, was relatively unimportant for present test conditions, since the drops spent most of their lifetime in fuel-rich regions of the flow where this distinction is irrelevant.
Bleaching and Hydroprocessing of Algal Biomass-Derived Lipids to Produce Renewable Diesel Fuel
Kruger, Jacob S.; Christensen, Earl D.; Dong, Tao; ...
2017-08-22
Algal lipids represent a promising feedstock for production of renewable diesel, but there is little information available regarding the integration of pretreatment, extraction, and catalytic upgrading steps. In this work, we examined oil bleaching by two methods and the effects of bleaching on oil deoxygenation over Pd/C and hydroisomerization over Pt/SAPO-11 catalysts. The raw oil was completely deoxygenated and 90% denitrogenated after dilution to 25 wt % in hexanes. The bleaching operations (using either a polar adsorbent or concentrated H 3PO 4) removed 85-90% of the nitrogen and led to 95-99% nitrogen removal after deoxygenation. Oil processability was also improvedmore » by bleaching. Here, the bulk chemistry of the deoxygenation and isomerization was not strongly affected by bleaching, as post-isomerization products with cloud points less than -10 °C and boiling ranges within or close to specification for No. 2 diesel fuel were obtained through 10 h time on stream with or without bleaching.« less
Kinetic Re-Evaluation of Fuel Neutralization by AKGA
NASA Technical Reports Server (NTRS)
Oropeza Cristina; Kosiba, Mike; Davis, Chuck
2010-01-01
Baseline characterization testing previously identified alpha-ketoglutaric acid (AKGA) cis a potential alternative to the current standard hydrazine (HZ) family fuel neutralization techniques in use at Kennedy Space Center (KSC). Thus far, the reagent shows promise for use in hardware decontamination operations and as a drop-in replacement for the scrubber liquor currently used in KSC four tower vapor scrubbers. Implementation of AKGA could improve process safety and reduce or eliminate generation of hydrazine-Iaden waste streams. This paper focuses on evaluation of the kinetics of these decontamination reactions in solution. Pseudo first order reaction rate constants with respect to the pyridazine products (6-oxo-4,5-dihydro-1H-pyridazine-3-carboxylic acid, (PCA) and 1-methyl-6-oxo-4,5-dihydro-pyridazine-3-carboxylic acid (mPCA)) in the presence of excess AKGA were determined by monitoring product formation using a ultra-violet visible absorption spectroscopy method. The results are presented here in comparison to previous data obtained by monitoring reactant depletion by gas chromatography with nitrogen phosphorus detector (GC-NPD).
Refining of Military Jet Fuels from Shale Oil. Part III. Pilot Plant Sample Preparation.
1982-07-01
product gas composition, regen- erator flue gas composition, and carbon contents of the spent and regenerated catalysts were also monitored for...product. Gas samples were collected at eight-hour intervals from the reactor product gas and regenerator flue gas streams and analyzed for material balance...Isobutane C4= Butylene C5 Pentane C5s Pentane and Pentenes I+ C5+, >C5 Compounds Heavier than Pentane in Gas .* Streams C6 Hexane C/H Carbon-to
NASA Astrophysics Data System (ADS)
Shi, Deyong; Song, Wenyan; Wang, Yuhang; Wang, Yanhua
2017-08-01
In this work, the effects of cavity flameholder configurations on flameholding and performances of kerosene fueled scramjet combustor were studied experimentally and numerically. For experiments, a directly connected ground facility was used and clean high enthalpy air, with a total temperature of 800 K and a total pressure of 800 Kpa, was provided by an electricity resistance heater. To investigate the effects of cavity configurations on flameholding capacity and reacting-flow characteristics, three different flameholders, one single cavity flameholder and two tandem cavity flameholders, were used in experiments. For the two combustors with tandem cavity flameholders, the location and configurations of its up-stream cavity were same with the single cavity flameholder, and the length-to-depth ratios for down-stream cavities were 9 and 11 respectively. The experimental results showed that stabilize kerosene combustion were achieved for combustor with tandem cavity flameholders mounted, and none for that with single cavity flameholder. The none-reacting and reacting flows of combustor models with tandem cavity flameholders were compared and studied with numerical and experimental results. The results showed that higher combustion efficiencies and pressure recovery ratios were achieved for the combustor with down-stream cavity length-to-depth ratio of 9.
da Silva, Teresa Lopes; Gouveia, Luísa; Reis, Alberto
2014-02-01
The production of microbial biofuels is currently under investigation, as they are alternative sources to fossil fuels, which are diminishing and their use has a negative impact on the environment. However, so far, biofuels derived from microbes are not economically competitive. One way to overcome this bottleneck is the use of microorganisms to transform substrates into biofuels and high value-added products, and simultaneously taking advantage of the various microbial biomass components to produce other products of interest, as an integrated process. In this way, it is possible to maximize the economic value of the whole process, with the desired reduction of the waste streams produced. It is expected that this integrated system makes the biofuel production economically sustainable and competitive in the near future. This review describes the investigation on integrated microbial processes (based on bacteria, yeast, and microalgal cultivations) that have been experimentally developed, highlighting the importance of this approach as a way to optimize microbial biofuel production process.
Kong, Peter C.; Detering, Brent A.
2003-08-19
Methods and systems for treating vapors from fuels such as gasoline or diesel fuel in an internal combustion engine, to form hydrogen gas or synthesis gas, which can then be burned in the engine to produce more power. Fuel vapor, or a mixture of fuel vapor and exhaust gas and/or air, is contacted with a plasma, to promote reforming reactions between the fuel vapor and exhaust gas to produce carbon monoxide and hydrogen gas, partial oxidation reactions between the fuel vapor and air to produce carbon monoxide and hydrogen gas, or direct hydrogen and carbon particle production from the fuel vapor. The plasma can be a thermal plasma or a non-thermal plasma. The plasma can be produced in a plasma generating device which can be preheated by contact with at least a portion of the hot exhaust gas stream, thereby decreasing the power requirements of the plasma generating device.
Kong, Peter C.; Detering, Brent A.
2004-10-19
Methods and systems are disclosed for treating vapors from fuels such as gasoline or diesel fuel in an internal combustion engine, to form hydrogen gas or synthesis gas, which can then be burned in the engine to produce more power. Fuel vapor, or a mixture of fuel vapor and exhaust gas and/or air, is contacted with a plasma, to promote reforming reactions between the fuel vapor and exhaust gas to produce carbon monoxide and hydrogen gas, partial oxidation reactions between the fuel vapor and air to produce carbon monoxide and hydrogen gas, or direct hydrogen and carbon particle production from the fuel vapor. The plasma can be a thermal plasma or a non-thermal plasma. The plasma can be produced in a plasma generating device which can be preheated by contact with at least a portion of the hot exhaust gas stream, thereby decreasing the power requirements of the plasma generating device.
TERMINAL ELECTRON ACCEPTING PROCESSES IN THE ALLUVIAL SEDIMENTS OF A HEADWATER STREAM
Chemical fluxes between catchments and streams are influenced by biochemical processes in the groundwater-stream water (GW-SW) ecotone, the interface between stream surface water and groundwater. Terminal electron accepting processes (TEAPs) that are utilized in respiration of ...
Separation of Carbon Monoxide and Carbon Dioxide for Mars ISRU-Concepts
NASA Technical Reports Server (NTRS)
LeVan, M. Douglas; Finn, John E.; Sridhar, K. R.
2000-01-01
Solid oxide electrolyzers, such as electrolysis cells utilizing yttria-stabilized zirconia, can produce oxygen from Mars atmospheric carbon dioxide and reject carbon monoxide and unreacted carbon dioxide in a separate stream. The oxygen-production process has been shown to be far more efficient if the high-pressure, unreacted carbon dioxide can be separated and recycled back into the feed stream. Additionally, the mass of the adsorption compressor can be reduced. Also, the carbon monoxide by-product is a valuable fuel for space exploration and habitation, with applications from fuel cells to production of hydrocarbons and plastics. In our research, we will design, construct, and test an innovative, robust, low mass, low power separation device that can recover carbon dioxide and carbon monoxide for Mars ISRU. Such fundamental process technology, involving gas-solid phase separation in a reduced gravitational environment, will help to enable Human Exploration and Development of Space. The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, respectively. In our research, we will design, construct, and test an innovative, robust, low mass, low power separation device that can recover carbon dioxide and carbon monoxide for Mars ISRU, Such fundamental process technology, involving gas-solid phase separation in a reduced gravitational environment, will help to enable Human Exploration and Development of Space. The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, Research needs for the design shown are as follows: (1) The best adsorbent for the process must be determined. (2) Adsorption isotherms must be measured, both for pure components and mixtures. (3) Mathematical modeling must be performed to provide a solid framework for design. (4) The separation system must be constructed and tested. (5) System integration must be studied.
Sociology: Clean-energy conservatism
NASA Astrophysics Data System (ADS)
McCright, Aaron M.
2017-03-01
US conservatives receive a steady stream of anti-environmental messaging from Republican politicians. However, clean-energy conservatives sending strong counter-messages on energy issues could mobilize moderate conservatives to break away from the dominant right-wing defence of fossil fuels.
40 CFR 60.56b - Standards for air curtain incinerators.
Code of Federal Regulations, 2010 CFR
2010-07-01
... fuel feed stream composed of 100 percent yard waste and no other municipal solid waste materials shall...-minute average) is permitted during startup periods during the first 30 minutes of operation of the unit...
State of Practice for Emerging Waste Conversion Technologies
New technologies to convert municipal and other waste streams into fuels and chemical commodities, termed conversion technologies, are rapidly developing. Conversion technologies are garnering increasing interest and demand due primarily to alternative energy initiatives. These t...
Coal-water slurry fuel internal combustion engine and method for operating same
McMillian, Michael H.
1992-01-01
An internal combustion engine fueled with a coal-water slurry is described. About 90 percent of the coal-water slurry charge utilized in the power cycle of the engine is directly injected into the main combustion chamber where it is ignited by a hot stream of combustion gases discharged from a pilot combustion chamber of a size less than about 10 percent of the total clearance volume of main combustion chamber with the piston at top dead center. The stream of hot combustion gases is provided by injecting less than about 10 percent of the total coal-water slurry charge into the pilot combustion chamber and using a portion of the air from the main combustion chamber that has been heated by the walls defining the pilot combustion chamber as the ignition source for the coal-water slurry injected into the pilot combustion chamber.
NASA Technical Reports Server (NTRS)
Schefer, R. W.; Sawyer, R. F.
1976-01-01
An opposed reacting jet combustor (ORJ) was tested at a pressure of 1 atmosphere. A premixed propane/air stream was stabilized by a counterflowing jet of the same reactants. The resulting intensely mixed zone of partially reacted combustion products produced stable combustion at equivalence ratios as low as 0.45. Measurements are presented for main stream velocities of 7.74 and 13.6 m/sec with an opposed jet velocity of 96 m/sec, inlet air temperatures from 300 to 600 K, and equivalence ratios from 0.45 to 0.625. Fuel lean premixed combustion was an effective method of achieving low NOx emissions and high combustion efficiencies simultaneously. Under conditions promoting lower flame temperature, NO2 constituted up to 100 percent of the total NOx. At higher temperatures this percentage decreased to a minimum of 50 percent.
Bingham, Dennis A.; Clark, Michael L.; Wilding, Bruce M.; Palmer, Gary L.
2007-05-29
A fueling facility and method for dispensing liquid natural gas (LNG), compressed natural gas (CNG) or both on-demand. The fueling facility may include a source of LNG, such as cryogenic storage vessel. A low volume high pressure pump is coupled to the source of LNG to produce a stream of pressurized LNG. The stream of pressurized LNG may be selectively directed through an LNG flow path or to a CNG flow path which includes a vaporizer configured to produce CNG from the pressurized LNG. A portion of the CNG may be drawn from the CNG flow path and introduced into the CNG flow path to control the temperature of LNG flowing therethrough. Similarly, a portion of the LNG may be drawn from the LNG flow path and introduced into the CNG flow path to control the temperature of CNG flowing therethrough.
Bingham, Dennis A.; Clark, Michael L.; Wilding, Bruce M.; Palmer, Gary L.
2005-05-31
A fueling facility and method for dispensing liquid natural gas (LNG), compressed natural gas (CNG) or both on-demand. The fueling facility may include a source of LNG, such as cryogenic storage vessel. A low volume high pressure pump is coupled to the source of LNG to produce a stream of pressurized LNG. The stream of pressurized LNG may be selectively directed through an LNG flow path or to a CNG flow path which includes a vaporizer configured to produce CNG from the pressurized LNG. A portion of the CNG may be drawn from the CNG flow path and introduced into the CNG flow path to control the temperature of LNG flowing therethrough. Similarly, a portion of the LNG may be drawn from the LNG flow path and introduced into the CNG flow path to control the temperature of CNG flowing therethrough.
Almeida, Jorge; Amaral, Lénia; Garcea, Frank E; Aguiar de Sousa, Diana; Xu, Shan; Mahon, Bradford Z; Martins, Isabel Pavão
2018-05-24
A major principle of organization of the visual system is between a dorsal stream that processes visuomotor information and a ventral stream that supports object recognition. Most research has focused on dissociating processing across these two streams. Here we focus on how the two streams interact. We tested neurologically-intact and impaired participants in an object categorization task over two classes of objects that depend on processing within both streams-hands and tools. We measured how unconscious processing of images from one of these categories (e.g., tools) affects the recognition of images from the other category (i.e., hands). Our findings with neurologically-intact participants demonstrated that processing an image of a hand hampers the subsequent processing of an image of a tool, and vice versa. These results were not present in apraxic patients (N = 3). These findings suggest local and global inhibitory processes working in tandem to co-register information across the two streams.
Radiation Stability of Benzyl Tributyl Ammonium Chloride towards Technetium-99 Extraction - 13016
DOE Office of Scientific and Technical Information (OSTI.GOV)
Paviet-Hartmann, Patricia; Horkley, Jared; Campbell, Keri
2013-07-01
A closed nuclear fuel cycle combining new separation technologies along with generation III and generation IV reactors is a promising way to achieve a sustainable energy supply. But it is important to keep in mind that future recycling processes of used nuclear fuel (UNF) must minimize wastes, improve partitioning processes, and integrate waste considerations into processes. New separation processes are being developed worldwide to complement the actual industrialized PUREX process which selectively separates U(VI) and Pu(IV) from the raffinate. As an example, the UREX process has been developed in the United States to co-extract hexavalent uranium (U) and hepta-valent technetiummore » (Tc) by tri-n-butyl phosphate (TBP). Tc-99 is recognized to be one of the most abundant, long-lived radio-toxic isotopes in UNF (half-life, t{sub 1/2} = 2.13 x 10{sup 5} years), and as such, is targeted in UNF separation strategies for isolation and encapsulation in solid waste-forms for final disposal in a nuclear waste repository. Immobilization of Tc-99 by a durable solid waste-form is a challenge, and its fate in new advanced technology processes is of importance. It is essential to be able to quantify and locate 1) its occurrence in any new developed flowsheets, 2) its chemical form in the individual phases of a process, 3) its potential quantitative transfer in any waste streams, and consequently, 4) its quantitative separation for either potential transmutation to Ru-100 or isolation and encapsulation in solid waste-forms for ultimate disposal. In addition, as a result of an U(VI)-Tc(VII) co-extraction in a UREX-based process, Tc(VII) could be found in low level waste (LLW) streams. There is a need for the development of new extraction systems that would selectively extract Tc-99 from LLW streams and concentrate it for feed into high level waste (HLW) for either Tc-99 immobilization in metallic waste-forms (Tc-Zr alloys), and/or borosilicate-based waste glass. Studies have been launched to investigate the suitability of new macro-compounds such as crown-ethers, aza-crown ethers, quaternary ammonium salts, and resorcin-arenes for the selective extraction of Tc-99 from nitric acid solutions. The selectivity of the ligand is important in evaluating potential separation processes and also the radiation stability of the molecule is essential for minimization of waste and radiolysis products. In this paper, we are reporting the extraction of TcO{sub 4}{sup -} by benzyl tributyl ammonium chloride (BTBA). Experimental efforts were focused on determining the best extraction conditions by varying the ligand's matrix conditions and concentration, as well as varying the organic phase composition (i.e. diluent variation). Furthermore, the ligand has been investigated for radiation stability. The ?-irradiation was performed on the neat organic phases containing the ligand at different absorbed doses to a maximum of 200 kGy using an external Co-60 source. Post-irradiation solvent extraction measurements will be discussed. (authors)« less
Bacterial biodegradation and bioconversion of industrial lignocellulosic streams.
Mathews, Stephanie L; Pawlak, Joel; Grunden, Amy M
2015-04-01
Lignocellulose is a term for plant materials that are composed of matrices of cellulose, hemicellulose, and lignin. Lignocellulose is a renewable feedstock for many industries. Lignocellulosic materials are used for the production of paper, fuels, and chemicals. Typically, industry focuses on transforming the polysaccharides present in lignocellulose into products resulting in the incomplete use of this resource. The materials that are not completely used make up the underutilized streams of materials that contain cellulose, hemicellulose, and lignin. These underutilized streams have potential for conversion into valuable products. Treatment of these lignocellulosic streams with bacteria, which specifically degrade lignocellulose through the action of enzymes, offers a low-energy and low-cost method for biodegradation and bioconversion. This review describes lignocellulosic streams and summarizes different aspects of biological treatments including the bacteria isolated from lignocellulose-containing environments and enzymes which may be used for bioconversion. The chemicals produced during bioconversion can be used for a variety of products including adhesives, plastics, resins, food additives, and petrochemical replacements.
Licursi, Domenico; Antonetti, Claudia; Martinelli, Marco; Ribechini, Erika; Zanaboni, Marco; Raspolli Galletti, Anna Maria
2016-03-01
Recycled paper needs a lot of mechanical/chemical treatments for its re-use in the papermaking process. Some of these ones produce considerable rejected waste fractions, such as "screen rejects", which include both cellulose fibers and non-fibrous organic contaminants, or "stickies", these last representing a shortcoming both for the papermaking process and for the quality of the final product. Instead, the accepted fractions coming from these unit operations become progressively poorer in contaminants and richer in cellulose. Here, input and output streams coming from mechanical screening systems of a papermaking plant using recycled paper for cardboard production were sampled and analyzed directly and after solvent extraction, thus confirming the abundant presence of styrene-butadiene rubber (SBR) and ethylene vinyl acetate (EVA) copolymers in the output rejected stream and cellulose in the output accepted one. Despite some significant drawbacks, the "screen reject" fraction could be traditionally used as fuel for energy recovery within the paper mill, in agreement with the integrated recycled paper mill approach. The waste, which still contains a cellulose fraction, can be also exploited by means of the hydrothermal route to give levulinic acid, a platform chemical of very high value added. Copyright © 2016 Elsevier Ltd. All rights reserved.
Co-flow anode/cathode supply heat exchanger for a solid-oxide fuel cell assembly
Haltiner, Jr., Karl J.; Kelly, Sean M.
2005-11-22
In a solid-oxide fuel cell assembly, a co-flow heat exchanger is provided in the flow paths of the reformate gas and the cathode air ahead of the fuel cell stack, the reformate gas being on one side of the exchanger and the cathode air being on the other. The reformate gas is at a substantially higher temperature than is desired in the stack, and the cathode gas is substantially cooler than desired. In the co-flow heat exchanger, the temperatures of the reformate and cathode streams converge to nearly the same temperature at the outlet of the exchanger. Preferably, the heat exchanger is formed within an integrated component manifold (ICM) for a solid-oxide fuel cell assembly.
Composite Bipolar Plate for Unitized Fuel Cell/Electrolyzer Systems
NASA Technical Reports Server (NTRS)
Mittelsteadt, Cortney K.; Braff, William
2009-01-01
In a substantial improvement over present alkaline systems, an advanced hybrid bipolar plate for a unitized fuel cell/electrolyzer has been developed. This design, which operates on pure feed streams (H2/O2 and water, respectively) consists of a porous metallic foil filled with a polymer that has very high water transport properties. Combined with a second metallic plate, the pore-filled metallic plates form a bipolar plate with an empty cavity in the center.
2012-12-10
combustion (IC) engine , Type 907, and its dat file was modified to match the expected fuel consumption and performance of the ...temperature output by the AS desorber. Depending on this DB set temperature, fuel would be burned to raise the temperature of the engine exhaust stream...in the simulations, it was based upon experimental data provided for this project indicating the performance of a 3 kW diesel
2015-01-01
requiring circulation of the electrolyte to filter out the carbonate solids. The superior power density of proton exchange membrane fuel cells ( PEMFC ...without requir- ing a CO2 free oxidant stream, prevented commercial develop- ment of the liquid AFC, allowing PEMFCs to dominate low temperature fuel...cell research and development. PEMFCs employ a solid acidic polymer to transport protons from anode to cathode. PEMs have been researched heavily the
Suppression of Low Strain Rate Nonpremixed Flames by an Agent
NASA Technical Reports Server (NTRS)
Olson, Sandra L. (Technical Monitor); Hamins, A.; Bundy, M.; Oh, C. B.; Park, J.; Puri, I. K.
2004-01-01
The extinction and structure of non-premixed methane/air flames were investigated in normal gravity and microgravity through the comparison of experiments and calculations using a counterflow configuration. From a fire safety perspective, low strain rate conditions are important for several reasons. In normal gravity, many fires start from small ignition sources where the convective flow and strain rates are weak. Fires in microgravity conditions, such as a manned spacecraft, may also occur in near quiescent conditions where strain rates are very low. When designing a fire suppression system, worst-case conditions should be considered. Most diffusion flames become more robust as the strain rate is decreased. The goal of this project is to investigate the extinction limits of non-premixed flames using various agents and to compare reduced gravity and normal gravity conditions. Experiments at the NASA Glenn Research Center's 2.2-second drop tower were conducted to attain extinction and temperature measurements in low-strain non-premixed flames. Extinction measurements using nitrogen added to the fuel stream were performed for global strain rates from 7/s to 50/s. The results confirmed the "turning point" behavior observed previously by Maruta et al. in a 10 s drop tower. The maximum nitrogen volume fraction in the fuel stream needed to assure extinction for all strain rates was measured to be 0.855+/-0.016, associated with the turning point determined to occur at a strain rate of 15/s. The critical nitrogen volume fraction in the fuel stream needed for extinction of 0-g flames was measured to be higher than that of 1-g flames.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Snowden-Swan, Lesley J.; Zhu, Yunhua; Jones, Susanne B.
A preliminary process model and techno-economic analysis (TEA) was completed for fuel produced from hydrothermal liquefaction (HTL) of sludge waste from a municipal wastewater treatment plant (WWTP) and subsequent biocrude upgrading. The model is adapted from previous work by Jones et al. (2014) for algae HTL, using experimental data generated in fiscal year 2015 (FY15) bench-scale HTL testing of sludge waste streams. Testing was performed on sludge samples received from MetroVancouver’s Annacis Island WWTP (Vancouver, B.C.) as part of a collaborative project with the Water Environment and Reuse Foundation (WERF). The full set of sludge HTL testing data from thismore » effort will be documented in a separate report to be issued by WERF. This analysis is based on limited testing data and therefore should be considered preliminary. Future refinements are necessary to improve the robustness of the model, including a cross-check of modeled biocrude components with the experimental GCMS data and investigation of equipment costs most appropriate at the smaller scales used here. Environmental sustainability metrics analysis is also needed to understand the broader impact of this technology pathway. The base case scenario for the analysis consists of 10 HTL plants, each processing 100 dry U.S. ton/day (92.4 ton/day on a dry, ash-free basis) of sludge waste and producing 234 barrel per stream day (BPSD) biocrude, feeding into a centralized biocrude upgrading facility that produces 2,020 barrel per standard day of final fuel. This scale was chosen based upon initial wastewater treatment plant data collected by the resource assessment team from the EPA’s Clean Watersheds Needs Survey database (EPA 2015a) and a rough estimate of what the potential sludge availability might be within a 100-mile radius. In addition, we received valuable feedback from the wastewater treatment industry as part of the WERF collaboration that helped form the basis for the selected HTL and upgrading plant scales and feedstock credit (current cost of disposal). It is assumed that the sludge is currently disposed of at $16.20/wet ton ($46/dry ton at 35% solids; $50/ton dry, ash-free basis) and this is included as a feedstock credit in the operating costs. The base case assumptions result in a minimum biocrude selling price of $3.8/gge and a minimum final upgraded fuel selling price of $4.9/gge. Several areas of process improvement and refinements to the analysis have the potential to significantly improve economics relative to the base case: • Optimization of HTL sludge feed solids content • Optimization of HTL biocrude yield • Optimization of HTL reactor liquid hourly space velocity (LHSV) • Optimization of fuel yield from hydrotreating • Combined large and small HTL scales specific to regions (e.g., metropolitan and suburban plants) Combined improvements believed to be achievable in these areas can potentially reduce the minimum selling price of biocrude and final upgraded fuel by about 50%. Further improvements may be possible through recovery of higher value components from the HTL aqueous phase, as being investigated under separate PNNL projects. Upgrading the biocrude at an existing petroleum refinery could also reduce the MFSP, although this option requires further testing to ensure compatibility and mitigate risks to a refinery. And finally, recycling the HTL aqueous phase product stream back to the headworks of the WWTP (with no catalytic hydrothermal gasification treatment) can significantly reduce cost. This option is uniquely appropriate for application at a water treatment facility but also requires further investigation to determine any technical and economic challenges related to the extra chemical oxygen demand (COD) associated with the recycled water.« less
Valve For Extracting Samples From A Process Stream
NASA Technical Reports Server (NTRS)
Callahan, Dave
1995-01-01
Valve for extracting samples from process stream includes cylindrical body bolted to pipe that contains stream. Opening in valve body matched and sealed against opening in pipe. Used to sample process streams in variety of facilities, including cement plants, plants that manufacture and reprocess plastics, oil refineries, and pipelines.
Cheng, R.K.
1998-04-07
A novel burner and burner method has been invented which burns an ultra lean premixed fuel-air mixture with a stable flame. The inventive burning method results in efficient burning and much lower emissions of pollutants such as oxides of nitrogen than previous burners and burning methods. The inventive method imparts weak swirl (swirl numbers of between about 0.01 to 3.0) on a fuel-air flow stream. The swirl, too small to cause recirculation, causes an annulus region immediately inside the perimeter of the fuel-air flow to rotate in a plane normal to the axial flow. The rotation in turn causes the diameter of the fuel-air flow to increase with concomitant decrease in axial flow velocity. The flame stabilizes where the fuel-air mixture velocity equals the rate of burning resulting in a stable, turbulent flame. 11 figs.
Cheng, Robert K.
1998-01-01
A novel burner and burner method has been invented which burns an ultra lean premixed fuel-air mixture with a stable flame. The inventive burning method results in efficient burning and much lower emissions of pollutants such as oxides of nitrogen than previous burners and burning methods. The inventive method imparts weak swirl (swirl numbers of between about 0.01 to 3.0) on a fuel-air flow stream. The swirl, too small to cause recirculation, causes an annulus region immediately inside the perimeter of the fuel-air flow to rotate in a plane normal to the axial flow. The rotation in turn causes the diameter of the fuel-air flow to increase with concomitant decrease in axial flow velocity. The flame stabilizes where the fuel-air mixture velocity equals the rate of burning resulting in a stable, turbulent flame.
Arrival metering fuel consumption analysis
DOT National Transportation Integrated Search
2011-01-01
Arrival metering is a method of time-based traffic management that is used by the Federal Aviation Administration to plan and manage streams of arrival traffic during periods of : high demand at busy airports. The Traffic Management Advisor is an aut...