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The development of precipitated iron catalysts with improved stability
The objective of this program is to identify the chemical principles governing the deactivation of precipitated iron catalysts during Fischer-Tropsch synthesis and to use these chemical principles in the design of catalysts suitable for slurry reactors. The performance targets are 88% CO+H{sub 2} conversion with less than 1% deactivation/day for 1 month and a methane and ethane selectivity of no more than 7% (based on hydrocarbons and oxygenates only) at a space velocity of at least 2 normal liters per hr per gram iron (NL/hr/gFe) using a synthesis gas with 0.5-1.0 H{sub 2}:CO ratio in a slurry reactor.
Chemical Technology Division Unit Operations Section Monthly Progress Report, September 1961
Nine samples of ThO/sub 2/ -UO/sub 2/ prepared as part of the solgel process development studies showed no consistent effects from small variations in several process parameters. The reaction of methane and copper oxide was studied. Engineering studies of the continuous dissolution of simulated U-Zr-Sn fuels in 6.5 M NH4F, 0.6-1.0 M NH/sub 4/NO/sub 3/, 0.1 M H/sub 2/O/sub 2/ were continued in modified 6-in.-dia. equipment. A total of 1642 kg of U from NaK bonded SRE Core I fuel rods wad dejacketed to date/su Initial operability tests of the 250 ton prototype shear unit showed a number of minor modifications are warranted. Center tube temperatures measured in a vertical 64 tube electrically heated simulated fuel element bundle were very near those previously obtained in the horizontal position. A 304 SS tube containing eutectic NaK was dissolved by HF in fused saIt at a tube wall penetration rate of approximates 2 mils/hr. Partial differential equations were derived from the concentration of unreacted UF/sub 6/ as a function of time and position in a sphere of NaF during sorption of UF/sub 6/. Calcium nitrate solution was added directly to the pot calciner during Purex feeding to give smoother operation of the feeding system. (auth)
Energy-Exchange Project
The purpose of the study was to determine what energy savings can be achieved by coordinating the resources and requirements of two facilities, the 26th Ward Water Pollution Control Plant (WPCP) and a housing development named Starrett City with its own total energy system. It was determined that three energy exchange options were economically and technically feasible. These include: the transfer of digester gas produced at the 26th Ward to the boilers at the Starrett City's total energy plant (TEP); the transfer of hot water heated at the TEP to the 26th Ward for space and process heating; and the transfer of coal effluent waste water from the 26th Ward to the condenser cooling systems at the TEP. Technical information is presented to support the findings. The report addresses those tasks of the statement of work dedicated to data acquisition, analysis, and energy conservation strategies internal to the Starrett City TEP and the community it supplies as well as to the 26th Ward WPCP. (MCW)
Establishment of viscometer capability for geopressured fluids. Project 61024 final report, November 19, 1978-December 31, 1979
The feasibility of modifying the IGT capillary viscometer for the measurement of methane-saturated brines at 10,000 psi and 200/sup 0/C was evaluated. The viscometer was cleaned, modified, reassembled and pressure treated. The density cells were calibrated to a precision of approximately 7%. The viscosity of pure value was measured and the best value obtained was 6% below values reported in the literature. The operation of the viscometer was time-consuming and required meticulous cleaning between experiments. Some corrosion at the mercury surface interfered with the efficient operation of the timing device. Other problems were encountered due to gas bubbles trapped in the capillary flow path. Consequently, data on methane-saturated brine could not be obtained within the funding limitations of this program. It is concluded that further work on the existing viscometer would not be cost-effective.
Energy from biological processes
This assessment responds to a request by the Senate Committee on Commerce, Science, and Transportation for an evaluation of the energy potential of various sources of plant and animal matter (biomass). This report complements an earlier OTA report on the Application of Solar Technology to Today's Energy Needs in evaluating the major solar energy resources available to the United States. The findings also will serve as part of the material to be used in an upcoming OTA assessment of synthetic fuels for transportation. This volume presents analyses of prominent biomass issues, summaries of four biomass fuel cycles, a description of biomass' place in two plausible energy futures, and discussions of policy options for promoting energy from biomass. The four fuel cycles - wood, alcohol fuels, grasses and crop residues, and animal wastes - were chosen because of their near- to mid-term energy potential and because of the public interest in them. A second volume presents technical analyses of the resource base, conversion technologies, and end uses that provide a basis for the discussion in this volume. Also included in Volume II are various unconventional approaches to bioenergy production as well as the use of biomass to produce chemicals.
Methane oxidation over dual redox catalysts
Review and analysis of the literature data on electron transfer itself and electron transfer oxidation of alkyl radicals was done in order to understand the mechanism by which methyl radical can be oxidized to CH{sub 3}{sup +} and further substituted by OH{sup {minus}} to form methanol. This allowed to compare and classify the various possible reaction patterns, understand the mechanism and circumstances of operation of each of them and select those which can be involved in oxidation of methyl radical. As a result an approach that is complementary to catalytic test studies was proposed. It consists of investigation of a set of partial reactions which reproduce a whole catalytic cycle in order to prove the reaction mechanism. Synthesis of new oxide catalysts of the delafossite type, containing concentrated double redox sites, were designed. Synthesis of hydrozincite as a starting material for the preparation of doubly doped zinc oxide was performed.
Diffusion of Slow Electrons in Gases
The properties of electrons in a gas and an external electric field, e.g., agitation velocity, free path, energy lost per collision, and collision cross sections, were determined for electrons of energy less than 2 ev in a large number of gases. The computations were made from previously measured values for Townsend's energy factor or the ratio of electron agitation energy to molecule thermal energy. Results are presented for hydrogen, nitrogen, carbon dioxide, methane, ethylene, cyclopropane, and argon. (D.L.C.)
Energy Program annual report
The national economy is particularly dependent on efficient electrical generation and transportation. Electrical demand continues to grow and will increasingly rely on coal and nuclear fuels. The nuclear power industry still has not found a solution to the problem of disposing of the waste produced by nuclear reactors. Although coal is in ample supply and the infrastructure is in place for its utilization, environmental problems and improved conversion processes remain technical challenges. In the case of transportation, the nation depends almost exclusively on liquid fuels with attendant reliance on imported oil. Economic alternates---synfuels from coal, natural gas, and oil shale, or fuel cells and batteries---have yet to be developed or perfected so as to impact the marketplace. Inefficiencies in energy conversion in almost all phases of resource utilization remain. These collective problems are the focus of the Energy Program.
Energy and protein production from pulp mill wastes. Progress report, June 15, 1977--September 15, 1977
Experiments conducted during this past quarter demonstrated the decided difference both in amount and composition of the gas produced from the fermentation of ozonated versus unozonated yeast-plant SSL. Gas from ozonated SSL averaged over 80% methane content while unozonated effluent was mostly carbon dioxide. Gas production rates and retention time studies indicated that the fermentation was substrate-limited. Preliminary tests using supplemental carbon sources have verified this. The success of the ozonation process in producing fermentable substrates was clearly shown by the appreciable yeast growth in the ozonated SSL. Of particular significance was the maximum yield obtained at the short ozonation time of 10 minutes as compared to the 2-hour treatment. It is possible that shortening the ozonation time could also increase the amount of substrate available for methane production. This would be very important in transferring this process to a commercial basis and reducing the operating costs.
Prairie Canal Well No. 1, Calcasieu Parish, Louisiana. Volume 1. Completion and testing. Final report
The Prairie Canal Company, Inc. Well No. 1, approximately 8 miles south of the city of Lake Charles, Louisiana, was tested through the annulus between 5-1/2 inch casing and 2-3/8 inch tubing. The interval tested was from 14,782 to 14,820 feet. The geological section was the Hackberry Sand, a member of the Oligocene Frio formation. Produced water was injected into a disposal well which was perforated in several Miocene Sands from 3070 to 4600 feet. Original plans were to test a section of the Hackberry sand from 14,976 to 15,024 feet. This primary zone, however, produced a large amount of sand, shale, gravel, and rocks during early flow periods and was abandoned in favor of the secondary zone. Four pressure drawdown flow tests and three pressure buildup tests were conducted during a 12-day period. A total of 36,505 barrels of water was produced. The highest sustained flow rate was approximately 7100 BWPD. The gas-to-water ratio, measured during testing, ranged from 41 to 50 SCF/BBL. There is disagreement as to the saturation value of the reservoir brine, which may be between 43.3 and 49.7 SCF/BBL. The methane content of the flare line gas averaged 88.4 mole percent. The CO/sub 2/ content averaged 8.4 mole percent. Measured values of H/sub 2/S in the gas were between 12 and 24 ppM.
Development of BEACON technology. Quarterly report, April-June 1982
The BEACON process involves the catalytic deposition of a highly reactive form of carbon from a gas stream which contains carbon monoxide. The carbon-depleted gas is combusted with air to produce power, and the carbon is reacted with steam to produce methane or hydrogen. Experiments were continued this quarter with the objective of improving the carbon deposition efficiency using a Paraho retort off-gas mixture. Analysis has shown that the use of the Paraho off-gas to make hydrogen would be attractive if the ratio of the heat content of the feedgas to the heat content of the hydrogen produced is less than 3. Experimental conditions to achieve this ratio have been established. Recent work had shown that the volume of a BEACON supported catalyst bed increased with an increase in carbon loading level. Four series of experiments were performed where sieve analyses were made after one or more BEACON process cycles. These tests showed that the volume expansion is due to an increase in the number and size of the larger catalyst particles. The bench-scale testing of unsupported catalysts concentrated in two areas: (a) the completion of batch testing in the 4-inch reactor, and (b) the construction of the Tandem Reactor Unit which will permit the transfer of solids between the carbon deposition and steam gasification reactors during testing. It was found that a second stage of steaming enhanced the methane yield. Approximately 80% of the construction and instrumentation of the Tandem Reactor Unit was completed during the quarter. A conceptual design was completed for an Integrated Test Facility (ITF) which would permit research on the BEACON process at a scale sufficient for scale-up. 17 figures, 14 tables.
Electron energy loss spectroscopy of CH/sub 3/N/sub 2/CH/sub 3/ adsorbed on Ni(100), Ni(111), Cr(100), Cr(111)
A study of the adsorption of CH/sub 3/N/sub 2/CH/sub 3/ on Ni(100), Ni(111), Cr(100), and Cr(111) using high resolution electron energy loss spectroscopy (EELS) is presented. Under approximately the same conditions of coverage, the vibrational spectra of CH/sub 3/N/sub 2/CH/sub 3/ on these four surfaces are quite distinct from one another, implying that the CH/sub 3/N/sub 2/CH/sub 3/-substrate interaction is very sensitive to the physical and electronic structure of each surface. In addition to the room temperature studies, the evolution of surface species on the Ni(100) surface in the temperature range 300 to 425 K was studied. Analysis of the Ni(100) spectra indicates that molecular adsorption, probably through the N lone pair, occurs at room temperature. Spectra taken after annealing the CH/sub 3/N/sub 2/CH/sub 3/-Ni(100) surfaces indicate that CH and CN bond scission occurred at the elevated temperatures. Decomposition of CH/sub 3/N/sub 2/CH/sub 3/ takes place on the Ni(111), Cr(100), and Cr(111) surfaces at room temperature, as evidenced by the intensity of the carbon-metal stretch in the corresponding spectra. Possible identities of coadsorbed dissociation products are considered. The stable coverage of surface species on all four surfaces at 300 K is less than one monolayer. A general description of an electron energy loss (EEL) spectrometer is given. Followed by a more specific discussion of some recent modifications to the EEL monochromator assembly used in this laboratory. Both the previous configuration of our monochromator and the new version are briefly described, as an aid to understanding the motivation for the changes as well as the differences in operation of the two versions. For clarity, the new monochromator design is referred to as variable pass, while the previous design is referred to as double pass. A modified tuning procedure for the new monochromator is also presented. 58 refs., 11 figs.
Methane entrained in geopressured aquifers, Texas Gulf Coast
Six tests of geopressured aquifers have yielded between 3.6 to 4.5 m/sup 3//m/sup 3/ (20 to 25 scf/bbl) of gas. These low gas concentrations are attributed to high salinities, that in all tests exceeded 100,000 mg/l, but undersaturated conditions cannot be ruled out completely. Research efforts are designed to delineate the geographic and stratigraphic variations in salinity and to recognize regional and local trends so that zones of lower salinity and higher gas concentration can be identified. Moreover, well logs and seismic data are being used to develop methods of detecting low concentrations of free gas in watered-out gas sands and in thin sands that were considered as noncommercial prior to renewed interest in unconventional gas supplies. (MHR)
Anaerobic fermentation of simulated in-situ oil shale retort water
The feasibility of removing soluble organics from oil shale retort water by anaerobic digestion with methane production was experimentally investigated. The following conclusions were made. The retort water studied had to be pretreated to remove toxic and add deficient constituents before it could be successfully treated with the anaerobic fermentation process. Pretreatment included pH adjustment to 7, ammonia reduction, and nutrient addition. A digested sludge from a conventional municipal sewage treatment plant was successfully acclimated to the retort water studied. A major fraction of the organics in the retort water studied was stabilized by conversion to CH/sub 4/ and CO/sub 2/ using the anaerobic fermentation process. BOD/sub 5/ and COD removal efficiences were 76 to 80 percent. The effluent from anaerobic fermentation of the retort water studied (BOD/sub 5/ : 530 to 580 mg/l) may be suitable for treatment by conventional aerobic processes. The growth of the methane formers, which stabilize the organics, is nutrient limited in the retort water studied. The pretreatment of the retort water studied removed 49 percent of the BOD/sub 5/. This was probably due to the reduction in solubility of high molecular weight fatty acids at neutral pHs. A major component removed from the retort water studied during anaerobic fermentation was fatty acids. The long hydraulic residence time used in this study would not be used in practice.
Evaluation of the gas production economics of the gas hydrate cyclic thermal injection model. [Cyclic thermal injection]
The objective of the work performed under this directive is to assess whether gas hydrates could potentially be technically and economically recoverable. The technical potential and economics of recovering gas from a representative hydrate reservoir will be established using the cyclic thermal injection model, HYDMOD, appropriately modified for this effort, integrated with economics model for gas production on the North Slope of Alaska, and in the deep offshore Atlantic. The results from this effort are presented in this document. In Section 1, the engineering cost and financial analysis model used in performing the economic analysis of gas production from hydrates -- the Hydrates Gas Economics Model (HGEM) -- is described. Section 2 contains a users guide for HGEM. In Section 3, a preliminary economic assessment of the gas production economics of the gas hydrate cyclic thermal injection model is presented. Section 4 contains a summary critique of existing hydrate gas recovery models. Finally, Section 5 summarizes the model modification made to HYDMOD, the cyclic thermal injection model for hydrate gas recovery, in order to perform this analysis.
Radicals in Irradiated Crystals Studied by ESR Spectroscopy. Technical Report, January 1--December 31, 1967
No Description Available.
Methane oxidation over dual redox catalysts
The objective of this research is to develop approaches to direct catalytic oxidation of methane over oxides that are doubly doped with transition metal ions. The desired process aims at employing a double redox mechanism, where one redox couple is utilized for activation of oxygen and another for the trapping of CH{sub 3} radicals. The methyl radicals can either recombine, giving C{sub 2} hydrocarbons, or be converted, via electron transfer reaction, to carbocations. The latter species can react with surface OH{sup {minus}} groups to form methanol or formaldehyde. To choose from several possible catalytic systems, this research initially involved the characterization of the micromorphology and crystalline dimensions of zinc oxide catalysts doped with Cu, Fe, and Sn by scanning electron microscopy. In addition, the determination of surface composition and oxidation states by X-ray photoelectron spectroscopy was carried out. A newly constructed high temperature catalytic testing system has been calibrated (flow meters and temperature controllers), tested for possible gas leaks and integrated with a gas chromatographic analytical unit. A preliminary catalytic test study over a Cu/Fe/ZnO sample was performed. The following products of the methane coupling reaction was found: C{sub 2}H{sub 6}, C{sub 2}H{sub 4} and H{sub 2}O together with CO{sub 2}. The maximum space time yield of 14 mmol C{sub 2} hydrocarbons/g cat/h was obtained at 848{degrees}C.
Investigation and evaluation of geopressured-geothermal wells
Over the life of the project, 1143 wildcat wells were screened for possible use. Although many did not meet the program's requirement for sand development, a surprisingly large number were abandoned because of downhole mechanical problems. Only 94 of these wells were completed as commercial hydrocarbon producers. Five wells of opportunity were funded for testing. Of these, two were evaluated for their hydraulic energy, thermal energy, and recoverable methane, and three were abandoned because of mechanical problems. (MHR)
Surface Motion Measurements. Project Pre-Schooner. Final Report.
No Description Available.
Development of BEACON technology. Quarterly report, October-December 1982
The BEACON process involves the catalytic deposition of a highly reactive form of carbon from a gas stream which contains carbon monoxide. The carbon-depleted gas is combusted with air to produce power, and the carbon is reacted with steam to produce methane or hydrogen. During the quarter both SOHIO and TRW worked on catalysts which would suppress methane formation during steaming thus increasing the amount of hydrogen formed. At SOHIO a C77-K2 catalyst promoted with a Class II compound showed promise in laboratory tests for suppressing methane. At TRW a K-1 unsupported catalyst promoted with 10% of Additive F maintained methane suppression over 30 cycles in laboratory scale tests. Shakedown of the Tandem Reactor Apparatus was completed and testing was initiated under quasi-continuous transfer of solids between reactors. Nine short term tests were performed with K-1 based BEACON solids. The data from these tests indicate that the Tandem Reactor concept is valid and BEACON solids can be transferred efficiently in the fluidized state between the deposition and gasification reactors. A preliminary analysis of the potential of a BEACON combined cycle/hydrogen system with a hydrogen fuel cell has been performed. The BEACON process can be used to coproduce hydrogen and electric power, and the efficiency of the overall system is quite high when the electricity is produced by a combined cycle power system. If fuel cells are used to convert the hydrogen to electricity then a system for making only electricity results, and such a system gives an overall efficiency of 54%. 7 figures, 14 tables.
Geopressured-geothermal energy development: government incentives and institutional structures
The following subjects are included: a geothermal resource overview, the evolution of the current Texas geopressured-geothermal institutional structure, project evaluation with uncertainty and the structure of incentives, the natural gas industry, the electric utility industry, potential governmental participants in resource development, industrial users of thermal energy, current government incentives bearing on geopressured-geothermal development, six profiles for utilization of the geopressured-geothermal resources in the mid-term, and probable impacts of new government incentives on mid-term resource utilization profiles. (MHR)
The carbon isotopic composition of atmospheric methane and its sources and trends; distribution of source fluxes and their contribution to the increasing concentration
The goal of isotopic studies of atmospheric methane is the determination of the relative fluxes of the various sources of different isotopic composition. Because of the large number of generic anthropogenic source types it is not possible to determine their relative strengths based on carbon-13 data alone. However, by combining sources of similar isotopic composition (as well as similar origin), and utilizing results from other studies it is possible to calculate some important features of the atmospheric CH{sub 4} cycle. The {sup 13}C/{sup 12}C ratio of atmospheric CH{sub 4} is increasing in both the southern and northern hemisphere with a faster rate in the former. Analysis of these results shows that the increasing fluxes of CH{sub 4} from biomass burning in the southern hemisphere contribute about 60% of the rate of increasing concentration. In the past decade the trend in the northern hemisphere can be interpreted as caused by both increasing and decreasing fluxes from the natural wetlands sources. 26 refs., 2 figs., 4 tabs.
Demonstration projects for coalbed methane and Devonian shale gas: Final report. [None]
In 1979, the US Department of Energy provided the American Public Gas Association (APGA) with a grant to demonstrate the feasibility of bringing unconventional gas such as methane produced from coalbeds or Devonian Shale directly into publicly owned utility system distribution lines. In conjunction with this grant, a seven-year program was initiated where a total of sixteen wells were drilled for the purpose of providing this untapped resource to communities who distribute natural gas. While coalbed degasification ahead of coal mining was already a reality in several parts of the country, the APGA demonstration program was aimed at actual consumer use of the gas. Emphasis was therefore placed on degasification of coals with high methane gas content and on utilization of conventional oil field techniques. 13 figs.
Development of BEACON technology. Quarterly report, January-March 1982
The BEACON process involves the catalytic deposition of a highly reactive form of carbon from a gas stream which contains carbon monoxide. The carbon-depleted gas is combusted with air to produce power, and the carbon is reacted with steam to produce methane or hydrogen. Process conditions favoring the production of hydrogen were explored this quarter. Excess steam was found to suppress methane formation, and reduction of catalyst methanation activity was demonstrated. The effect of carbon loading on the physical stability of catalyst C77-K2 and the effect of trace sulfur levels on the chemical stability of the catalyst were examined. The carbon loading tests did not show the catalyst breakup that was expected. Tests of chemical stability of the catalyst in the presence of sulfur-containing gases showed a decline in performance even at levels as low as 4 ppM. Experiments conducted using a Paraho-type oil shale retort offgas as a feedstock showed that acceptable performance could be obtained by removing carbon dioxide from the feedgas. Design of the tandem two reactor system is continuing, along with cold flow testing of the proposed solids transfer system. A simplified thermodynamic analysis of the BEACON process shows that BEACON's increased efficiency over competing processes results from more hot gas going to the turbine with less power required to compress the air for combustion. 16 figures, 13 tables.
Pyrolysis of Wyoming subbituminous coal. [Pyrolysis at 500 and 625/sup 0/C; gas evolution and tar production may play significant roles in in-situ coal gascation; pyrolysis gas mainly CO/sub 2/, CO, H/sub 2/, and CH/sub 4/]
No Description Available.
L-star pulsed coal combustor for residential space heating
This quarter, substantial improvement in the coal carbon conversion was achieved. Specifically, for a scaled-down version of the residential combustor, coal carbon conversions exceeding 97 percent were realized, when utilizing methane as carrier gas for the coal. Design changes include insulation of the combustor, introduction of a flame holder, combustion air preheat and presence of an obstructing plate at the combustor exhaust port. Only the first two changes contributed towards substantial improvement in coal conversion. In addition, monitoring of CH{sub 4} concentration in the exhaust gases gave a real time indication of the combustor performance. Finally, the results of experiments performed in this quarter contributed to design changes that have led to a combustor that has achieved the program goal of > 99 percent conversion of coal carbon. 5 figs., 2 tabs.
Plasma-Induced Conversion of Surface-Adsorbed Hydrocarbons
Experimental results are reported for an electrical device for direct conversion of methane into higher hydrocarbons. A microchannel plate is excited with electrons from a photoemissive source, and electron impact ionization of methane on the inner surfaces of the microchannels creates an ion feedback process. The resulting low-density plasma creates higher hydrocarbons when charged particles impact the surfaces at grazing incidence. The production Of C{sub 2} to C{sub 8}-containing gases was noted, with a selectivity for C{sub 2} of 39% in one case. The proportions of converted products and the conversion rates depend upon the electrical voltage, the microchannel geometry, and the operating pressure. Conversion rates increase with operating pressure.
Halogen Atom Reactions Activated by Radiative Neutron Capture and /sup 82m/ Br and /sup 130m/I Isomeric Transition. Progress Report No. 4, February 1969-- February 1970
No Description Available.
Fundamental studies of catalytic gasification
Studies of the catalytic steam gasification of carbon solids continued. In this project a considerable number of important findings have been made. Recently limited experimentation has been carried out on the production of C{sub 2} hydrocarbons from methane in the presence of Ca/K/Ni oxide catalysts and of oxygen, carbon and water. The main finding thus far has been that C{sub 2} yields of 10--13% can be obtained at about 600{degrees}C or 150{degrees} lower temperature than described in the literature for similar yields. Work during this quarter was largely concentrated on oxidative methane coupling. Gasification of a petroleum coke is also discussed. 5 tabs.
REACTIONS OF IODINE ACTIVATED BY RADIATIVE NEUTRON CAPTURE AND ISOMERIC TRANSITION WITH GASEOUS AND CONDENSED STATE POLYHALOMETHANES.
No Description Available.
Yttria-stabilized zirconia solid oxide electrolyte fuel cells, monolithic solid oxide fuel cells
Small cell size, thin ceramic components, and high operating temperature are the key features of the MSOFC. The small size of individual cells in the monolithic structure increases the active surface area. For example, an MSOFC with channels about 1 mm in diameter has a ratio of active surface area to volume of about 9.4 sq cm/cu cm. This is about seven times the ratio for conventional fuel cells. On this basis alone, an MSOFC with a channel diameter of 1 mm should produce the same power as a conventional fuel cell seven times as large. The high current density of the MSOFC results from the small cell size and ensuing low internal resistance. The current density is high at the fuel inlet end of the fuel channel where the thermodynamic driving force (Nernst potential) is highest. Similarly, the current density is low at the outlet end of the fuel channel where the Nernst potential is lowest. Because of the high operating temperature of the MSOFC (1000{degrees}C),hydrocarbon fuels can be reformed in the fuel channels. The reform reaction produces hydrogen which is consumed by the fuel cell. Catalytic reforming of methane and natural gas within a solid oxide fuel cell has been demonstrated.
Binding and catalytic reduction of NO by transition metal aluminosilicates
The objective of this research is to provide the scientific understanding of processes that actively and selectively reduce NO in dilute exhaust streams, as well as in concentrated streams, to N{sub 2}. Experimental studies of NO chemistry in transition metal-containing aluminosilicate catalysts are being carried out with the aim of determining the chemical rules for NO reduction on non-precious metals. The catalyst supports chosen for this investigation are A and Y zeolites, mordenite, and monoliths based on cordierite. The supported transition metal cations that were examined are principally the first row redox metals, e.g. Cr(2), Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Cu(I). The reactions of interest are the reductions of NO by H{sub 2}, CO, and CH{sub 4}, as well as the disproportionation of NO. Rare earth cations that possess redox properties were placed in the more shielded sites, e.g. Site I in Y zeolite, prior to or simultaneously with the exchange procedure with the transition metal cations. Theoretical calculations of the electronic structure of the transition metal cations in zeolitic sites were carried out by ab initio methods. The aim of this part of the research is to find the best match between the metal-based antibonding orbitals and the antibonding orbitals of the NO molecule such that the N-O bond is weakened and is readily broken. 9 refs., 4 figs., 3 tabs.
Assessment of microbial processes on gas production at radioactive low-level waste disposal sites
Factors controlling gaseous emanations from low level radioactive waste disposal sites are assessed. Importance of gaseous fluxes of methane, carbon dioxide, and possible hydrogen from the site, stems from the inclusion of tritium and/or carbon-14 into the elemental composition of these compounds. In that the primary source of these gases is the biodegradation of organic components of the waste material, primary emphasis of the study involved an examination of the biochemical pathways producing methane, carbon dioxide, and hydrogen, and the environmental parameters controlling the activity of the microbial community involved. Initial examination of the data indicates that the ecosystem is anaerobic. As the result of the complexity of the pathway leading to methane production, factors such as substrate availability, which limit the initial reaction in the sequence, greatly affect the overall rate of methane evolution. Biochemical transformations of methane, hydrogen and carbon dioxide as they pass through the soil profile above the trench are discussed. Results of gas studies performed at three commercial low level radioactive waste disposal sites are reviewed. Methods used to obtain trench and soil gas samples are discussed. Estimates of rates of gas production and amounts released into the atmosphere (by the GASFLOW model) are evaluated. Tritium and carbon-14 gaseous compounds have been measured in these studies; tritiated methane is the major radionuclide species in all disposal trenches studied. The concentration of methane in a typical trench increases with the age of the trench, whereas the concentration of carbon dioxide is similar in all trenches.
Salinity variations and chemical compositions of waters in the Frio Formation, Texas Gulf Coast. Annual report
Waters produced from sandstone reservoirs of the deep Frio Formation exhibit spatial variations in chemical composition that roughly coincide with the major tectonic elements (Houston and Rio Grande Embayments, San Marcos Arch) and corresponding depositional systems (Houston and Norias deltas, Greta-Carancahua barrier/strandplain system) that were respectively active along the upper, lower, and middle Texas Coast during Frio deposition. Within an area, salinities are usually depth dependent, and primary trends closely correspond to pore pressure gradients and thermal gradients. Where data are available (mainly in Brazoria County) the increases in TDS and calcium with depth coincide with the zone of albitization, smectite-illite transition, and calcite decrease in shales. Waters have fairly uniform salinities when produced from the same sandstone reservoir within a fault block or adjacent fault blocks with minor displacement. In contrast, stratigraphically equivalent sandstones separated by faults with large displacement usually yield waters with substantially different salinities owing to the markedly different thermal and pressure gradients across the faults that act as barriers to fluid movement.
Measurement and effect of the critical gas saturation and relative permeability on the production of methane from geopressured aquifers of saturated brine
The attempt to measure critical gas saturation at pressures in the range of 5000 to 10,000 psi failed. It proved impossible, with the funds and time available, to conclude a successful suite of experiments. The problem was centered on the inability to maintain adequate seals on the end plates of the apparatus. Numerical simulation confirmed that the level of critical gas saturation required for methane to be produced profitably from geopressured aquifers was unrealistically high. Most of the water driven geopressured gas reservoirs located through a study of the USGS files revealed that there is in general an inadequate level of available data on them. Furthermore, the size of these reservoirs were in general so small that their total gas content would not merit any significant expenditure to win the residual, trapped gas.
The development of precipitated iron catalysts with improved stability
The objective of this program is to identify the chemical principles governing the deactivation of precipitated iron catalysts during Fischer-Tropsch synthesis and to use these chemical principles in the design of catalysts suitable for slurry reactors. The performance targets are 88% CO+H{sub 2} conversion with less than 1% deactivation/day for 1 month and a methane and ethane selectivity of no more than 7% (based on hydrocarbons and oxygenates only) at a space velocity of at least 2 normal liters per hr per gram iron (NL/hr/gFe) using a synthesis gas with 0.5-1.0 H{sub 2}:CO ratio in a slurry reactor.
Vertical borehole design and completion practices used to remove methane gas from mineable coalbeds
Coalbed gas drainage from the surface in advance of mining has long been the goal of researchers in mine safety. Bureau of Mines efforts to achieve this goal started about 1965 with the initiation of an applied research program designed to test drilling, completion, and production techniques for vertical boreholes. Under this program, over 100 boreholes were completed in 16 different coalbeds. The field methods derived from these tests, together with a basic understanding of the coalbed reservoir, represent an available technology applicable to any gas drainage program whether designed primarily for mine safety or for gas recovery, or both.
Biological conversion of organic refuse to methane. Final report, July 1, 1973--November 30, 1976
In order to predict accurately the cost of producing methane from urban refuse, studies were initiated on the dewatering of the fermentor residue and the disposal of the residue from the system. Results of the research are reported under the following subject headings: fermentation system; rheological properties of reactor slurry; filterability of reactor effluent; residue dewatering--vacuum filtration; settleability of solids in the reactor effluent; settleability of sludges from centrate treatment; centrifugation of reactor effluent; leachate potential of dewatered reactor residue; calorific value of the reactor residue; residue incineration; the production of panelboards; caustic treatment of digester feed; and, treatment of filtrate--centrate. Appendixes A, B, D, and E are included; Appendix C, which includes computer programs and documentation, is bound separately as Volume II of this report. (JGB)
Biological conversion of biomass to methane. Final report, June 1, 1976-January 31, 1980
An experimental methane fermentation system was constructed for the purpose of evaluating the processng requirements and conversion efficiencies associated with production of methane from various organic feed stocks. The fermentation reactors had an operating volume 0.775 m/sup 3/. This permitted operation with an approximate continuous feed of milled organics including beef feedlot manure, corn stover, wheat straw and alfalfa hay. A thermochemical pretreatment was applied to the corn stover and wheat straw in order to increase the biodegradability of these substrates. Working with these large units provided sufficient volumes of fermented slurry for evaluation of the dewatering properties of these slurries. Kinetic data were obtained by operating four reactors at different retention times. These data were used to calculate a first order rate constant and the percent of substrate volatile solids that were biodegradable. These data were obtained on beef feed lot manure at 40/sup 0/C and 60/sup 0/C nominal fermentation temperatures. Data from the fermentation of corn stover showed that the biodegradability of the stover volatile solids was only 36 percent at the thermophilic fermentation temperature. The first order rate constant was found to be 0.25 day/sup -1/. Thermochemical pretreatment increased the biodegradability of stover volatile solids to 71 percent. The final substrate tested was a green crop that was field dried - alfalfa. Significant foaming problems were encountered with this material. The volatile solids were found to be 74 percent biodegradable at a fermentation temperature of 60/sup 0/C. (MHR)
Methane or methanol via catalytic gasification of biomass
Methane and methanol synthesis gas can be produced by steam gasification of biomass in the presence of appropriate catalysts. A 5 cm diameter reactor has been used to determine the desired catalysts and operating temperature. A process development unit (PDU) has demonstrated steam gasification of biomass with catalysts at rates up to 35 kg per hour. Methane yields of 0.28 nm/sup 3/ per kg of dry wood were produced in the small laboratory reactor. Further methanation of the product gas mixture can increase methane yields to 0.33 nm/sup 3//kg. The catalyst system is nickel and silica-alumina. The preferred reactor operating temperature is 500 to 550/sup 0/C. Tests have been at atmospheric pressure. The PDU performance has confirmed results obtained in the laboratory. Methanol synthesis gas can be produced in a single stage reactor at 750 to 850/sup 0/C by steam gasification of wood with silica-alumina and nickel catalysts present. From this gas, up to 0.6 kg of methanol can be produced per kg of wood. Gasification of the wood to produce synthesis gas has been demonstrated in the laboratory scale reactor, but remains to be successfully done using the PDU. Catalyst deactivation rates and regeneration schemes must be determined in order to determine the economic feasibility of wood to methane or methanol processes. Some advantages of catalytic steam gasification of biomass over steam-oxygen gasification are: no oxygen is required for methane or methanol synthesis gas, therefore, no oxygen plant is needed; little or no tar is produced resulting in simpler gas cleaning equipment; no shift reactor is required for methanol synthesis; methanation requirements are low resulting in high conversion efficiency; and yields and efficiencies are greater than obtained by conventional gasification.
Fluid sampling and chemical modeling of geopressured brines containing methane. Final report, March 1980-February 1981
The development of a flowthrough sampler capable of obtaining fluid samples from geopressured wells at temperatures up to 400/sup 0/F and pressures up to 20,000 psi is described. The sampler has been designed, fabricated from MP35N alloy, laboratory tested, and used to obtain fluid samples from a geothermal well at The Geysers, California. However, it has not yet been used in a geopressured well. The design features, test results, and operation of this device are described. Alternative sampler designs are also discussed. Another activity was to review the chemistry and geochemistry of geopressured brines and reservoirs, and to evaluate the utility of available computer codes for modeling the chemistry of geopressured brines. The thermodynamic data bases for such codes are usually the limiting factor in their application to geopressured systems, but it was concluded that existing codes can be updated with reasonable effort and can usefully explain and predict the chemical characteristics of geopressured systems, given suitable input data.
Unit Operations Section Monthly Progress Report, November 1961
Openation of a 6-in.-dia foam separation column with Sr/sup 89/ tracer and dodecylbenzenesulfonate as a surfactant and foaming agent was continued. The catalytic oxidation of H/sub 2/, CO, and CH/sub 4/ was studied using a nickel- chromepalladium ribbon catalyst. A Mark I prototype fuel assembly was sheared to within 1.5-in. of the end by modifying the gas hydraulic system of the shear. The force required to shear a highly carburized Mark I fuel assembly ductile tubing. Demonstration of the mechanical dejacketing of the SRE Core I fuel burned to approximates 675 Mwd/ton and cooled about 2 years is complete, and decontamination and equipment removal from the segmenting cell is approximately 90% complete. Ten SRE Core I fuel jackets were dissolved in aqua regia and analysis showed negligible U and Pu. A semicontinuous leach run, in which -2 mesh graphite fuel containing 2.6% U was leached in 90% HNO/sub 3/ at 60 deg C, gave only 0.37% U loss. Graphically estimated spectral factors for radiation between tubes within fuel bundles and improved wall radiation factors were rised to calculate the temperature distribution expected within spent fuel elements. Further studies of the dissolution of zirconium oxide by HF in fused salt resulted in rates about twice as great as for Zr metal under similar conditions. (auth)
Secondary Isotope Effects in Molecular Structure
A study was made to determine whether secondary iso tope effects also occur in molecular structure. Electron diffraction studies were carried out on ethane and deuteroethane. In C/sub 2/H/sub 6/ the mean C-C and C-H bond lengths found agreed very closely with values determined for other paraffin hydrocarbons, and the C--H bond showed a normal primary isotope effect (~ 0.005 A) similar to that found in methane when H is replaced by O. The output of the leastsquares analysis suggested that the mean C-- C bond length in C/sub 2/D/sub 6/ is shorter than in C/sub 2/H/sub 6/ and by about 0.004 A. Th e decrease seemed to be real for the apparent uncertainty was not much greater than 0.001 A. (M.C.G.)
Monfort waste conversion demonstration. Quarterly progress report, January 1, 1977--March 31, 1977
Research efforts on the development of a mobile fermentation system centered on the evaluation of various start-up procedures. Although good gas production has been achieved with a system operated at 125/sup 0/F/51.7/sup 0/C and with a total volatile acid concentration of 2000 to 4000 mg/l, it is suggested that these conditions might cause stresses on the system that would make it more susceptible to failure. Progress in tests on start-up and operation of the system at 135/sup 0/F/57.2/sup 0/C and total volatile acid concentration of 1000 mg/l is reported. (JGB)
Geopressured energy availability. Final report
Near- and long-term prospects that geopressured/geothermal energy sources could become a viable alternative fuel for electric power generation were investigated. Technical questions of producibility and power generation were included, as well as economic and environmental considerations. The investigators relied heavily on the existing body of information, particularly in geotechnical areas. Statistical methods were used where possible to establish probable production values. Potentially productive geopressured sediments have been identified in twenty specific on-shore fairways in Louisiana and Texas. A total of 232 trillion cubic feet (TCF) of dissolved methane and 367 x 10/sup 15/ Btu (367 quads) of thermal energy may be contained in the water within the sandstone in these formations. Reasonable predictions of the significant reservoir parameters indicate that a maximum of 7.6 TCF methane and 12.6 quads of thermal energy may be producible from these potential reservoirs.
Assessment of methane-related fuels for automotive fleet vehicles: technical, supply, and economic assessments
The use of methane-related fuels, derived from a variety of sources, in highway vehicles is assessed. Methane, as used here, includes natural gas (NG) as well as synthetic natural gas (SNG). Methanol is included because it can be produced from NG or the same resources as SNG, and because it is a liquid fuel at normal ambient conditions. Technological, operational, efficiency, petroleum displacement, supply, safety, and economic issues are analyzed. In principle, both NG and methanol allow more efficient engine operation than gasoline. In practice, engines are at present rarely optimized for NG and methanol. On the basis of energy expended from resource extraction to end use, only optimized LNG vehicles are more efficient than their gasoline counterparts. By 1985, up to 16% of total petroleum-based highway vehicle fuel could be displaced by large fleets with central NG fueling depots. Excluding diesel vehicles, which need technology advances to use NG, savings of 8% are projected. Methanol use by large fleets could displace up to 8% of petroleum-based highway vehicle fuel from spark-ignition vehicles and another 9% from diesel vehicles with technology advances. The US NG supply appears adequate to accommodate fleet use. Supply projections, future price differential versus gasoline, and user economics are uncertain. In many cases, attractive paybacks can occur. Compressed NG now costs on average about $0.65 less than gasoline, per energy-equivalent gallon. Methanol supply projections, future prices, and user economics are even more uncertain. Current and projected near-term methanol supplies are far from adequate to support fleet use. Methanol presently costs more than gasoline on an equal-energy basis, but is projected to cost less if produced from coal instead of NG or petroleum.
Rate and pressure dependence of contaminants in vacuum deposited aluminum films
Experiments were conducted to measure the quantity of trapped impurities in electron beam-deposited aluminum films. The depositions were conducted at the 1.3 x 10/sup -4/ Pa to 1.3 x 10/sup -2/ Pa pressure range with rates varying from a few A/sec to 70 A/sec. An RGA was used to record the residual gas spectrum before and during all runs. The films were analyzed by sputter profiling and Auger Electron Spectroscopy. The chief contaminants found were carbon and oxygen. The carbon contaminant tracked the gauge pressure over two orders of magnitude, ranging from a few atomic percent to the 500 to 1000 ppM range. The partial pressures of H/sub 2/O, O/sub 2/, and other gases were varied during deposition to determine their individual roles in contaminating the films. As a result, a relationship between the residual gas spectrum and chemical analysis was found. 5 figures.
Gas evolution from geopressured brines
The process of gas evolution from geopressured brine is examined using as a basis the many past studies of gas evolution from liquids in porous media. A discussion of a number of speculations that have been made concerning gas evolution from geopressured brines is provided. According to one, rapid pressure reduction will cause methane gas to evolve as when one opens a champagne bottle. It has been further speculated that evolved methane gas would migrate up to form an easily producible cap. As a result of detailed analyses, it can be concluded that methane gas evolution from geopressured brines is far too small to ever form a connected gas saturation except very near to the producing well. Thus, no significant gas cap could ever form. Because of the very low solubility of methaned in brine, the process of methane gas evolution is not at all analogous to evolution of carbon dioxide from champagne. A number of other speculations and questions on gas evolution are analyzed, and procedures for completing wells and testing geopressured brine reservoirs are discussed, with the conclusion that presently used procedures will provide adequate data to enable a good evaluation of this resource.
Recovery of anaerobic digestion after exposure to toxicants. Final report
The concept that methane fermentation cannot tolerate chronic or slug doses of toxicants has almost totally precluded methane fermentation as a viable contender for the treatment of industrial wastewaters. This study assayed a wide variety of toxicants, heavy metals, inorganic salts, organic chemicals, solvents, and antibiotics which are used in industrial processes and, therefore, appear in the industrial wastewaters therefrom. Toxicity was related to the reduction in methane production of a control containing no toxicant. The response of methane fermentation after exposure to a toxicant was assayed with unacclimated cultures as well as cultures which had been acclimated to increasing concentrations of the toxicant over long periods of time. The reversible nature of the toxicants was assayed by adding slug doses to plug flow anaerobic filters and recording gas production prior to, during, and after toxicant addition.
District heating and cooling systems for communities through power plant retrofit distribution network. Phase 2. Final report, March 1, 1980-January 31, 1984. Volume IV
This volume contains the following: discussion of cost estimating methodology, detailed cost estimates of Hudson No. 2 retrofit, intermediate thermal plant (Kearny No. 12) and local heater plants; transmission and distribution cost estimate; landfill gas cost estimate; staged development scenarios; economic evaluation; fuel use impact; air quality impact; and alternatives to district heating.
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