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Investigation of the use of a recycle stream to mediate hydrogen transfer to improve the conversion of eastern oil shale to liquid products

Description: The processing of eastern oil shale has long been known to require the addition of hydrogen to increase the oil yield. Several researchers, have investigated the use of both high pressure hydrogen and hydrogen donor solvents. Much of the donor solvent work has used pure,compounds such as tetralin and has not addressed the use of-a more realistic solvent such as one derived from the production process itself. The work reported herein is for the research Task 1.2.2, Process Studies, in the Annual Project Plan, October l, 1990--September 30, 1991, of the Cooperative Agreement. In the study, a shale oil-derived, recycle oil was used to mediate the transfer of hydrogen to eastern oil shale. The work was divided into two main parts which correspond to the two main portions of the Hydrogen-Extraction (H-E{trademark}) process: (1) the shale oil extraction which involves the use of a donor solvent to aid in the extraction of the shale oil and (2) the regeneration of the donor solvent to a hydrogen-rich state ready for recycle. The results of the investigation to evaluate shale oil extraction using a shale oil-derived donor solvent suggest that temperature had the, greatest effort on organic conversion. At a temperature of 425{degrees}C (197{degrees}F), a yield of 130% of Fischer assay was obtained using tetralin as a donor solvent. At the same temperature, only 110% of Fischer assay could be obtained using a middle distillate as a donor solvent.
Date: June 1, 1944
Creator: Barbour, F. A.; Guffey, F. D.; Thomas, K. P. & Blake, R. F.
Partner: UNT Libraries Government Documents Department

Chemistry of coal model compounds: cleavage of aliphatic bridges between aromatic nuclei catalyzed by Lewis acids. [M. S. thesis]

Description: The condensed polynuclear aromatic clusters of coal are believed to be linked principally by straight-chain aliphatic bridges varying from 0 to 4 carbon atoms in length and the cleavage of these linkages is expected to be an important step in the coal liquefaction process. This study focuses on the means by which Lewis acid catalysts, specifically AlCl/sub 3/ and ZnCl/sub 2/, promote the cleavage of these linkages. To facilitate product identification and interpretation of reaction mechanisms, organic compounds which model the aliphatic bridges were used on substrates. All experiments were performed in a magnetically stirred autoclave under either an H/sub 2/ or N/sub 2/ atmosphere at elevated pressure to determine the role of H/sub 2/. Reaction temperatures ranging from 200 to 350/sup 0/C were used to avoid the complication of pyrolysis reactions. Reaction products were identified with the aid of gas chromatography/mass spectrometry, and quantitative product yields were determined by gas chromatography. Experiments with AlCl/sub 3/ and the substrates containing two phenyl rings linked by 0 to 4 carbon atoms showed that AlCl/sub 3/ catalyzed cleavage of all the aliphatic bridges. ZnCl/sub 2/ was totally inactive in cleaving the alkyl bridges in these compounds. Substitution of a phenyl group by a hydroxyphenyl or a naphthyl group in the model compounds promoted the cleavage of aliphatic linkages in the presence of AlCl/sub 3/. In contrast to reactions with the diphenylalkanes, ZnCl/sub 2/ was also found to catalyze the cleavage of these compounds. Plausible reaction mechanisms are proposed which explain the experimental results. The role of gaseous H/sub 2/ in these mechanisms was also investigated.
Date: April 1, 1978
Creator: Taylor, N.D.
Partner: UNT Libraries Government Documents Department

Chemical structures and reactivities of coal as an organic natural product

Description: Some chemical reactions involved in coal liquefaction have been studied using carbon 14 labelled compounds and nuclear magnetic resonance. On the basis of these studies it is concluded that the role of tetralin during coal conversion is (1) to act as a dispersion vehicle; (2) to supply hydrogen radicals, when needed, to trap coal radicals, and (3) in a very minor way to undergo intermolecular reaction with the coal through making and breaking of C--C (and possibly other) bonds. As a result of other experiments it is concluded that to the methods previously employed for breaking bonds in coal molecules and thereby lowering their molecular weights, must now be added the use of solvated-electrons for breaking -CH/sub 2/--CH/sub 2/- linkages. A possible mechanism for the cleavage of bibenzyl (used as a model compound for coal) is given. (LTN)
Date: January 1, 1979
Creator: Collins, C J; Hombach, H P; Benjamin, B M; Roark, W H; Maxwell, B & Raaen, V F
Partner: UNT Libraries Government Documents Department

General quantitative model for coal liquefaction kinetics: the thermal cleavage/hydrogen donor capping mechanism. [59 references]

Description: A mechanism for coal liquefaction, based on the concept of thermal cleavage-hydrogen capping donor complexes, is proposed and the quantitative agreement between the derived rate laws and the kinetic data obtained from fifteen publications is presented. The mechanism provides rate laws which describe the preasphaltene, asphaltene, oil and gas time/yield curves for the coal liquefaction process. A simplistic dissolution model is presented and used to relate the proposed mechanism to the experimentally observed products. Based on the quality of the mechanistic fit to the reported coal liquefaction systems, which cover a diverse range of reaction conditions, coal types and donor solvent compositions, it is proposed that the donor solvent/thermal bond cleavage/hydrogen capping mechanism provides a good, quantitative description of the rate limiting process. Interpretation of the rate constant/temperature dependencies in terms of transition state theory indicates formation of the activated complex can involve either physically or chemically controlled steps. A uniform free energy of activation of 52 kcal was found for the diverse liquefaction systems indicating a common transition state describes the reactions. Thus the proposed mechanism unifies the diverse liquefaction kinetic data by using a set of uniform reaction sequences, which have a common transition state, to describe the conversion chemistry. The mechanism thereby creates a common base for intercomparison, interpretation and evaluation of coal conversion for the broad range of processes currently being investigated in the liquefaction field.
Date: January 1, 1980
Creator: Gangwer, T
Partner: UNT Libraries Government Documents Department

Hydrogen-transfer and charge transfer in photochemical and high energy radiation induced reactions: effects of thiols. Final report, February 1, 1960-january 31, 1979

Description: Absorption of ultraviolet or visible light, or high energy radiation, may lead to highly reactive free radicals. Thiols affect the reactions of these radicals in the following ways: (1) transfer of hydrogen from sulfur of the thiol to a substrate radical, converting the radical to a stable molecule, and the thiol to a reactive thiyl radical; and (2) transfer of hydrogen from a substrate radical or molecule to thiyl, regenerating thiol. The thiol is thus used repeatedly and a single molecule may affect the consequences of many quanta. Three effects may ensue, depending upon the system irradiated: (1) the substrate radicals may be converted by thiol-thiyl to the original molecules, and protection against radiation damage is afforded. (2) The radicals may be converted to molecules not identical with the starting materials, and in both cases damage caused by radical combination processes is prevented. (3) Product yields may be increased where the initial radicals might otherwise regenerate starting materials. It was shown that rates of reaction of excited species can be correlated with triplet energies and reduction potentials, and with ionization potentials, that amines are very reactive toward excited carbonyl compounds of all types, and that yields of products from these reactions can be increased by thiols, leading to increased efficiency in utilization of light.
Date: March 1, 1980
Creator: Cohen, S G
Partner: UNT Libraries Government Documents Department

Fossil Energy Program. Progress report for April 1980

Description: This report - the sixty-ninth of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology, component and process evaluation studies, technical support to major liquefaction projects, process analysis and engineering evaluations, fossil energy environmental analysis, coal preparation and waste utilization, coal preparation plant automation, atmospheric fluidized bed coal combustor for cogeneration, technical support to the TVA fluidized bed combustion demonstration plant program, coal cogeneration/district heating plant assessment, performance assurance system support, and international energy technology assessment.
Date: June 1, 1980
Creator: McNeese, L.E.
Partner: UNT Libraries Government Documents Department

Fossil energy program. Progress report for June 1980

Description: This report - the seventy-first of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology, component and process evaluation studies, technical support to major liquefaction projects, process analysis and engineering evaluation, fossil energy environmental analysis, coal preparation and waste utilization, coal preparation plant automation, atmospheric fluidized bed coal combustor for cogeneration, TVA fluidized combustion demonstration plant program technical support, coal cogeneration/district heating plant assessment, performance assurance system support, and international energy technology assessment.
Date: August 1, 1980
Creator: McNeese, L.E.
Partner: UNT Libraries Government Documents Department

Fossil energy program. Progress report for May 1980

Description: This report - the seventieth of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology, component and process evaluation studies, technical support to major liquefaction projects, process analysis and engineering evaluations, fossil energy environmental analysis, coal preparation and waste utilization, coal preparation plant automation, technical support to the TVA fluidized bed combustion demonstration plant program, coal cogeneration/district heating plant assessment, atmospheric fluidized bed coal combustor for cogeneration, performance assurance system support and international energy technology assessment.
Date: August 1, 1980
Creator: McNeese, L.E.
Partner: UNT Libraries Government Documents Department

Applied research and evaluation of process concepts for liquefaction and gasification of western coals. Final report

Description: Fourteen sections, including five subsections, of the final report covering work done between June 1, 1975 to July 31, 1980 on research programs in coal gasification and liquefaction have been entered individually into EDB and ERA. (LTN)
Date: September 1, 1980
Creator: Wiser, W. H.
Partner: UNT Libraries Government Documents Department

Chemistry and morphology of coal liquefaction. Annual report, October 1, 1979-September 30, 1980

Description: The present annual report summarizes quarterly reports and includes work performed during the last quarter of fiscal 1980. The first year of this project has just been completed and much of the time and effort has been concentrated on equipment building, assembling, testing, and on staffing. This, of course, has been more true in the areas of work with spectroscopic and high pressure equipment than in organic chemical reactions. More experimental results are therefore reported in the areas of hydrogen transfer mechanisms and catalysis and organo-metallic chemistry. A few of the significant results in these and other areas are the evidence for catalysis in hydrogen transfer from tetralin; a novel and possibly very important new synthesis of alkyl aromatics from benzene, carbon monoxide, and hydrogen; the study of coals in the transmission electron microscope identifying coal macerals, minerals and metals, and leading to the possibility of observing location of and catalytic influences on pyrolysis and hydrogenation at elevated temperatures; the finding that scales formed on deactivated cobalt-molybdena-alumina-hydrogenation catalysts contain not only metals from the liquid feedstocks, but also molybdenum sulfide which must derive from migration from the catalyst interior to and beyond the surface. Insights gained in mechanisms of pyrolysis, hydrogenation, hydrogen transfer, and indirect liquefaction of coal promise to lead to improving technology by defining problem areas and showing routes to by-pass problems.
Date: September 1, 1980
Creator: Heinemann, H.
Partner: UNT Libraries Government Documents Department

Fossil energy program. Progress report, July 1980

Description: This report - the seventy-second of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology, component development and process evaluation, technical support to major liquefaction projects, process and program analysis, fossil energy environmental analysis, coal preparation and waste utilization, coal preparation plant automation, atmospheric fluidized bed coal combustor for cogeneration, technical support to the TVA fluidized bed combustion demonstration plant program, fossil energy applications assessments, performance assurance system support for fossil energy projects, international assessment of atmospheric fluidized bed combustion technology, and PFBC systems analysis.
Date: October 1, 1980
Creator: McNeese, L. E.
Partner: UNT Libraries Government Documents Department

Neutron scattering and the 30 S ribosomal subunit of E. coli

Description: This paper reviews the progress made in the study of the internal organization of the 30 S ribosomal subunit of E. coli by neutron scattering since 1975. A map of that particle showing the position of 14 of the subunit's 21 proteins is presented, and the methods currently used for collecting and analyzing such data are discussed. Also discussed is the possibility of extending the interpretation of neutron mapping data beyond the limits practical today. 30 references, 5 figures.
Date: January 1, 1982
Creator: Moore, P.B.; Engelman, D.M.; Langer, J.A.; Ramakrishnan, V.R.; Schindler, D.G.; Schoenborn, B.P. et al.
Partner: UNT Libraries Government Documents Department

Solvent tailoring in coal liquefaction. Quarterly report, February 1982-May 1982. [In many cases the simple organic compounds listed were hydrogenated]

Description: Twenty-three model donor solvents were used to rank their efficacy for the dissolution of Western Kentucky No. 9/14 coal. The transfer of hydrogen from the solvent to the coal fragments, as measured by coal conversion, was examined at three levels of available hydrogen. The hydrogen donors are ranked according to their ability to convert coal to THF solubles. Aromatic analogs of the model donors showed little ability to convert coal to THF solubles. Factors which influence hydrogen donation include the presence of heteroatoms or substituents both internal and external to the aromatic or hydroaromatic rings, the degree of hydrogenation, the aromaticity or nonaromaticity of the hydroaromatics, and the presence of five-membered rings. A relationship between heats of formation and hydrogen donor ability was shown for hydroaromatics within two ring or three ring homologous series. A model hydrogen acceptor, benzophenone, was also used to rank model donors and a comparison was made with the model donor ranking by coal conversion. The ranking of hydrogen donors at the same donatable hydrogen level for their ability to convert coal to THF solubles demonstrates that different donors have different abilities to liquefy coal. The presence of donatable hydrogen constitutes a necessary and important factor in coal conversion as evidenced by comparison with the conversion aromatic analogs. However, properties of the model donors other than the concentration of available hydrogen can affect THF solubles. The ease with which hydrogen is abstracted from a particular donor, as well as the functional groups and heteroatoms present, are significant factors affecting reactivity of the hydrogen donors during liquefaction. Ranking of hydrogen donor reactivity by coal conversion and by model acceptor experiments shows no direct correlation between the two.
Date: January 1, 1982
Creator: Tarrer, A.R.; Guin, J.A.; Curtis, C.W. & Williams, D.C.
Partner: UNT Libraries Government Documents Department

Studies in coal liquefaction with application to the SRC and related processes. Quarterly report, November 1981-January 1982

Description: The concentration of hydroaromatics in a coal liquefaction solvent is regarded as a significant factor in the determination of solvent quality. An analytical method is described based on catalytic solvent dehydrogenation (CSD) for the measurement of transferable hydrogen, including hydroaromatic sources, in a solvent. The dehydrogenation of several model compounds in the presence of Pd/CaCO/sub 3/ was conducted under batch conditions. Hydroaromatics containing six-member rings were found to dehydrogenate effectively. Lesser degrees of dehydrogenation were found for alkyl-substituted aromatics and saturated compounds. CSD was applied to a series of hydrogenated creosote oils plus several light recycle oils. The normalized H/sub 2/ volumes obtained by CSD could be correlated with the coal-dissolution ability of the creosote oils. It was not possible to include the light recycle oils in the same correlation. /sup 13/C-NMR was used to measure the transferable hydrogen of selected hydrogenated creosote oils and light recycle oils. Values of transferable hydrogen determined by /sup 13/C-NMR were generally larger than the corresponding values obtained by CSD. A smooth correlation was found between coal conversion and transferable hydrogen as measured by /sup 13/C-NMR. The light recycle oils could not be fitted to the curve defined by the creosote oils. Minerals indigenous to coal provide an internal but weak source of catalytic activity during liquefaction reactions. A sensitive probe reaction, cyclohexene hydrogenation/isomerization, was used to compare the catalytic activity of several clay minerals, oxides used as catalyst supports, pyrite and liquefaction residue ashes.
Date: January 1, 1982
Creator: Tarrer, A.R.; Guin, J.A. & Curtis, C.W.
Partner: UNT Libraries Government Documents Department

Exploratory study of coal conversion chemistry. Quarterly report No. 2, August 19, 1981-November 18, 1981. [Hydroxydipnenylmethanes, triphenylmethane, diphenylether]

Description: This report describes work accomplished under two tasks: Task A, mechanisms of donor-solvent coal liquefaction, and Task B, CO/H/sub 2/O conversion systems. Under Task A, we describe additional evidence relating to the question of the mechanism of the iron oxide catalyzed cleavage of hydroxydiphenylmethanes. o-Hydroxydiphenylmethane is relatively more sensitive to catalysis by Fe/sub 3/O/sub 4/, a possible one electron oxidant, and triphenylmethane is relatively more sensitive to catalyzed cleavage by SiO/sub 2//Al/sub 2/O/sub 3/, a strong Bronsted acid catalyst. This provides further evidence that in the former case the reactions of radical cations are important in the cleavage mechanism. Tests with Cr/sub 2/O/sub 3/ show it to be ineffective under our reaction conditions as a catalyst for hydroxydiphenylmethane cleavage. We have also used the decomposition of diphenylether in tetralin, which we have previously shown to occur by a radical displacement reaction, as an indicator of steady state radical concentration in tetralin. The results of these experiments indicate that radical concentrations in tetralin are not significantly increased by spiking the tetralin with 1,2-dihydronaphthalene. This in turn suggests that rapid disproportionation of 1,2-dihydronaphthalene to tetralin and naphthalene takes place by way of a concerted reaction, in addition to a slower radical disproportionation process that may provide the steady state radical concentration supported by the equilibrium concentration of 1,2-dihydronaphthalene. Under Task B1, we have found a correlation between initial pH and CO pressure on the conversion of PSOC-26 coal to toluene soluble products. A pH dependence was also observed for PSOC-233 coal, similar to results with PSOC-26. Under Task B2, we have studied anisole as a model oxygen containing structure in coal.
Date: January 29, 1982
Partner: UNT Libraries Government Documents Department

Exploratory study of coal conversion chemistry. Quarterly report No. 10, August 19-November 18, 1983

Description: Work has continued to focus this quarter on Subtask A.3, Derivation of an Improved Correlation Between Coal-Conversion Effectiveness and Donor-Solvent Structure. We are taking two new approaches to test the hypothesis that the critical class of reactions, which distinguishes between good donor and poor donor solvents, is bimolecular transfer of hydrogen atoms from solvent radicals to the ipso positions of substituted aromatics Ar-X, resulting in solvent-mediated hydrogenolysis. In the first approach, experiments in which real coal liquefaction mixtures were doped with specific model compounds showed that hydrogen-transfer reactions promoted by the coal do engender bond scission in the dinaphthylmethane to an extent that the half-life for cleavage at 400/sup 0/C in tetralin is decreased from 200 hours to about 4 hours. This result greatly strengthens our suggestion that the cleavage of phenyl-alkyl bonds, formerly considered to be very refractory under liquefaction conditions, may play an important role in coal liquefaction. In the second approach to testing our liquefaction mechanism hypothesis, we have constructed a simplified numerical model for liquefaction of some coal-like structures, incorporating some of the rate constants for bond cleavage measured in this work to determine whether the calculated relative bond cleavage rate with various hydroaromatic contents successfully mimics the relative model compound and coal conversion rates measured in the laboratory. Our efforts in Task B were concentrated on Subtask B.1 Development and Evaluation of CO/H/sub 2/O Catalyst Systems. The study of conversion behavior of an Illinois No. 6 coal was extended to different reaction times and lower pH's. The results reveal that the primary reaction parameter that controls coal conversion at 400/sup 0/C is the amount of CO that is allowed to enter the reaction pathway. 24 references, 8 tables.
Date: December 1, 1983
Creator: Ross, D.S.; McMillen, D.F.; Chang, S.J.; Hum, G.P.; Green, T.K. & Malhotra, R.
Partner: UNT Libraries Government Documents Department

Improved performance in coprocessing through fundamental and mechanistic studies in hydrogen transfer and catalysis. Quarterly report, September 26, 1989--December 26, 1989

Description: To gain a fundamental understanding of the role and importance of hydrogen transfer reactions in thermal and catalytic coprocessing by examining possible hydrogen donation from cycloalkane/aromatic systems and by understanding the chemistry and enhanced reactivity of hydrotreated residuum, as well as by enriching petroleum solvent with potent new donors, nonaromatic hydroaromatics, thereby promoting hydrogen transfer reactions in coprocessing. The detailed results of experiments performed on several subtasks during the quarter are presented.
Date: December 31, 1989
Creator: Curtis, C. W.
Partner: UNT Libraries Government Documents Department

Studies of coal reactivity for direct liquefaction

Description: This paper presents a preliminary report on a continuing effort to quantify the reactivity of coal for direct liquefaction reactions in terms of the utilization of hydrogen, the selectivity to products and the properties of the products formed. Liquefaction processes are aimed at maximizing the yield of distillate that can serve as hydrocarbon fuels and chemical feedstocks. This study seeks to better describe: (1) how hydrogen consumed during liquefaction is distributed among product groups; (2) coal reactivity in terms of a relationship defining the selectivity to products formed during liquefaction; and (3) the relation of coal structure to reactivity for liquefaction reactions. Because of the limited space for reporting this effort in this special edition of Fuel, the experimental methods, calculations and data are presented in abbreviated form in order to focus on interpretation and discussion of the results in terms of coal structure and reactivity. 30 refs., 3 figs., 2 tabs.
Date: January 1, 1990
Creator: Stephens, H.P. & Kottenstette, R.J.
Partner: UNT Libraries Government Documents Department

The Wilsonville Advanced Coal Liquefaction Research and Development Facility, Wilsonville, Alabama

Description: The investigation of various Two-Stage Liquefaction (TSL) process configurations was conducted at the Wilsonville Advanced Coal Liquefaction R D Facility between July 1982 and September 1986. The facility combines three process units. There are the liquefaction unit, either thermal (TLU) or catalytic, for the dissolution of coal, the Critical Solvent Deashing unit (CSD) for the separation of ash and undissolved coal, and a catalytic hydrogenation unit (HTR) for product upgrading and recycle process solvent replenishment. The various TSL process configurations were created by changing the process sequence of these three units and by recycling hydrotreated solvents between the units. This report presents a description of the TSL configurations investigated and an analysis of the operating and performance data from the period of study. Illinois No. 6 Burning Star Mine coal Wyodak Clovis Point Mine coal were processed. Cobalt-molybdenum and disposable iron-oxide catalysts were used to improve coal liquefaction reactions and nickel-molybdenum catalysts were used in the hydrotreater. 28 refs., 31 figs., 13 tabs.
Date: May 1, 1990
Partner: UNT Libraries Government Documents Department

The Wilsonville Advanced Coal Liquefaction Research and Development Facility, Wilsonville, Alabama

Description: This reports presents the operating results for Run 252 at the Advanced Coal Liquefaction R D Facility in Wilsonville, Alabama. This run operated in the Close-Coupled Integrated Two-Stage Liquefaction mode (CC-ITSL) using Illinois No. 6 bituminous coal. The primary run objective was demonstration of unit and system operability in the CC-ITSL mode with catalytic-catalytic reactors and with ash recycle. Run 252 began on 26 November 1986 and continued through 3 February 1987. During this period 214.4 MF tons of Illinois No. 6 coal were fed in 1250 hours of operation. 3 refs., 29 figs., 18 tabs.
Date: May 1, 1990
Partner: UNT Libraries Government Documents Department

Variational transition state theory calculations of tunneling effects on concerted hydrogen motion in water clusters and formaldehyde/water clusters

Description: The direct participation of water molecules in aqueous phase reaction processes has been postulated to occur via both single-step mechanisms as well as concerted hydrogen atom or proton shifts. In the present work, simple prototypes of concerted hydrogen atom transfer processes are examined for small hydrogen-bonded water clusters -- cyclic trimers and tetramers -- and hydrogen-bonded clusters of formaldehyde with one and two water molecules. Rate constants for the rearrangement processes are computed using variational transition state theory, accounting for quantum mechanical tunneling effects by semiclassical ground-state adiabatic transmission coefficients. The variational transition state theory calculations directly utilize selected information about the potential energy surface along the minimum energy path as parameters of the reaction path Hamiltonian. The potential energy information is obtained from ab ignite electronic structure calculations with an empirical bond additivity correction (the BAC-MP4 method). Tunneling is found to be very important for these concerted rearrangement processes -- the semiclassical ground-state adiabatic transmission coefficients are estimated to be as high as four order of magnitude at room temperature. Effects of the size of the cluster (number of water molecules in the cyclic complex) are also dramatic -- addition of a water molecule is seen to change the calculated rates by orders of magnitude. 36 refs., 10 figs.
Date: August 1, 1990
Creator: Garrett, B.C. (Pacific Northwest Lab., Richland, WA (USA)) & Melius, C.F. (Sandia National Labs., Livermore, CA (USA))
Partner: UNT Libraries Government Documents Department

New Albany shale flash pyrolysis under hot-recycled-solid conditions: Chemistry and kinetics, II

Description: The authors are continuing a study of recycle retorting of eastern and western oil shales using burnt shale as the solid heat carrier. Stripping of adsorbed oil from solid surfaces rather than the primary pyrolysis of kerogen apparently controls the release rate of the last 10--20% of hydrocarbons. Thus, the desorption rate defines the time necessary for oil recovery from a retort and sets the minimum hold-time in the pyrolyzer. A fluidized-bed oil shale retort resembles a fluidized-bed cat cracker in this respect. Recycled burnt shale cokes oil and reduces yield. The kerogen H/C ratio sets an upper limit on yield improvements unless external hydrogen donors are introduced. Steam can react with iron compounds to add to the H-donor pool. Increased oil yield when New Albany Shale pyrolyzes under hot-recycled-solid, steam-fluidization conditions has been confirmed and compared with steam retorting of acid-leached Colorado oil shale. In addition, with retorted, but unburnt, Devonian shale present at a recycle ratio of 3, the authors obtain 50% more oil-plus-gas than with burnt shale present. Procedures to make burnt shale more like unburnt shale can realize some increase in oil yield at high recycle ratios. Reduction with H{sub 2} and carbon deposition are possibilities that the authors have tested in the laboratory and can test in the pilot retort. Also, eastern spent shale burned at a high temperature (775 C, for example) cokes less oil than does spent shale burned at a low temperature (475 C). Changes in surface area with burn temperature contribute to this effect. 15 refs., 8 figs., 4 tabs.
Date: November 1, 1990
Creator: Coburn, T.T. & Morris, C.J.
Partner: UNT Libraries Government Documents Department

Improved performance in coprocessing through fundamental and mechanistic studies in hydrogen transfer and catalysis. Quarterly report, December 26, 1989--March 26, 1990

Description: To gain a fundamental understanding of the role and importance of hydrogen transfer reactions in thermal and catalytic coprocessing by examining possible hydrogen donation from cycloalkane/aromatic systems and by understanding the chemistry and enhanced reactivity of hydrotreated residuum, as well as by enriching petroleum solvent with potent new donors, nonaromatic hydroaromatics, thereby promoting hydrogen transfer reactions in coprocessing. The detailed results of experiments performed on several subtasks during the quarter are presented.
Date: December 31, 1990
Creator: Curtis, C. W.
Partner: UNT Libraries Government Documents Department

Improved performance in coprocessing through fundamental and mechanistic studies in hydrogen transfer and catalysis. Quarterly report, September 27, 1990--December 26, 1990

Description: The objective is to gain a fundamental understanding of the role and importance of hydrogen transfer reactions in thermal and catalytic coprocessing by examining possible hydrogen donation from cycloalkane/aromatic systems and by understanding the chemistry and enhanced reactivity of hydrotreated residuum, as well as by enriching petroleum solvent with potent new donors, nonaromatic hydroaromatics, thereby promoting hydrogen transfer reactions in coprocessing. The detailed results of experiments performed on several subtasks during the quarter are presented.
Date: December 31, 1990
Creator: Curtis, C. W.
Partner: UNT Libraries Government Documents Department