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Sample records for fischer-tropsch slurry catalysts

  1. Separation of catalyst from Fischer-Tropsch slurry

    DOEpatents

    White, C.M.; Quiring, M.S.; Jensen, K.L.; Hickey, R.F.; Gillham, L.D.

    1998-10-27

    In a catalytic process for converting synthesis gas including hydrogen and carbon monoxide to hydrocarbons and oxygenates by a slurry Fischer-Tropsch synthesis, the wax product along with dispersed catalyst is removed from the slurry and purified by removing substantially all of the catalyst prior to upgrading the wax and returning a portion to the Fischer-Tropsch reaction. Separation of the catalyst particles from the wax product is accomplished by dense gas and/or liquid extraction in which the organic compounds in the wax are dissolved and carried away from the insoluble inorganic catalyst particles that are primarily inorganic in nature. The purified catalyst-free wax product can be subsequently upgraded by various methods such as hydrogenation, isomerization, hydrocracking, conversion to gasoline and other products over ZSM-5 aluminosilicate zeolite, etc. The catalyst particles are returned to the Fischer-Tropsch Reactor by mixing them with a wax fraction of appropriate molecular weight, boiling point and viscosity to avoid reactor gelation. 2 figs.

  2. Separation of catalyst from Fischer-Tropsch slurry

    DOEpatents

    White, Curt M.; Quiring, Michael S.; Jensen, Karen L.; Hickey, Richard F.; Gillham, Larry D.

    1998-10-27

    In a catalytic process for converting synthesis gas including hydrogen and carbon monoxide to hydrocarbons and oxygenates by a slurry Fischer-Tropsch synthesis, the wax product along with dispersed catalyst is removed from the slurry and purified by removing substantially all of the catalyst prior to upgrading the wax and returning a portion to the Fischer-Tropsch reaction. Separation of the catalyst particles from the wax product is accomplished by dense gas and/or liquid extraction in which the organic compounds in the wax are dissolved and carried away from the insoluble inorganic catalyst particles that are primarily inorganic in nature. The purified catalyst free wax product can be subsequently upgraded by various methods such as hydrogenation, isomerization, hydrocracking, conversion to gasoline and other products over ZSM-5 aluminosilicate zeolite, etc. The catalyst particles are returned to the Fischer-Tropsch Reactor by slurring them with a wax fraction of appropriate molecular weight, boiling point and viscosity to avoid reactor gelation.

  3. Separation of catalyst from Fischer-Tropsch slurry

    SciTech Connect

    White, C.M.; Quiring, M.S.; Jensen, K.L.; Hickey, R.F.; Gillham, L.D.

    1998-04-01

    This paper describes a process for the separation of catalysts used in Fischer-Tropsch synthesis. The separation is accomplished by extraction in which the organic compounds in the wax are dissolved and carried away from the insoluble inorganic catalyst particles that are primarily inorganic. The purified catalyst can be upgraded by various methods.

  4. Processes and catalysts for conducting Fischer-Tropsch synthesis in a slurry bubble column reactor

    DOEpatents

    Singleton, A.H.; Oukaci, R.; Goodwin, J.G.

    1999-08-17

    Processes and catalysts are disclosed for conducting Fischer-Tropsch synthesis in a slurry bubble column reactor (SBCR). One aspect of the invention involves the use of cobalt catalysts without noble metal promotion in an SBCR. Another aspect involves using palladium promoted cobalt catalysts in an SBCR. Methods for preparing noble metal promoted catalysts via totally aqueous impregnation and procedures for producing attrition resistant catalysts are also provided. 1 fig.

  5. Processes and catalysts for conducting fischer-tropsch synthesis in a slurry bubble column reactor

    DOEpatents

    Singleton, Alan H.; Oukaci, Rachid; Goodwin, James G.

    1999-01-01

    Processes and catalysts for conducting Fischer-Tropsch synthesis in a slurry bubble column reactor (SBCR). One aspect of the invention involves the use of cobalt catalysts without noble metal promotion in an SBCR. Another aspect involves using palladium promoted cobalt catalysts in an SBCR. Methods for preparing noble metal promoted catalysts via totally aqueous impregnation and procedures for producing attrition resistant catalysts are also provided.

  6. Development and process evaluation of improved Fischer-Tropsch slurry catalysts. Final report

    SciTech Connect

    Bukur, D.B.; Mukesh, D.; Patel, S.A.; Zimmerman, W.H.; Rosynek, M.P.; Kellogg, L.J.

    1990-04-01

    This report describes results of a study aimed at developing and evaluating improved catalysts for a slurry Fischer-Tropsch (FT) process for converting synthesis gas to high quality transportation fuels (gasoline and distillate). The improvements in catalyst performance were sought by studying effects of pretreatment conditions, promoters and binders/supports. A total of 20 different, iron based, catalysts were evaluated in 58 fixed bed reactor tests and 10 slurry reactor tests. The major accomplishments and conclusions are summarized below. The pretreatment conditions (temperature, duration and the nature of reducing gas) have significant effect on catalyst performance (activity, selectivity and stability) during Fischer-Tropsch synthesis. One of precipitated unsupported catalysts had hydrocarbon selectivity similar to Mobil`s I-B catalyst in high wax mode operation, and had not experienced any loss in activity during 460 hours of testing under variable process conditions in a slurry reactor. The effect of promoters (copper and potassium) on catalyst performance during FT synthesis has been studied in a systematic way. It was found that potassium promotion increases activities of the FT and water-gas-shift (WGS) reactions, the average molecular weight of hydrocarbon products, and suppresses the olefin hydrogenation and isomerization reactions. The addition of binders/supports (silica or alumina) to precipitated Fe/Cu/K catalysts, decreased their activity but improved their stability and hydrocarbon selectivity. The performance of catalysts of this type was very promising and additional studies are recommended to evaluate their potential for use in commercial slurry reactors.

  7. Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst

    SciTech Connect

    Chanenchuk, C.A.; Yates, I.C.; Satterfield, C.N.

    1990-01-01

    A Co/MgO/SiO[sub 2] Fischer-Tropsch catalyst was operated simultaneously with a Cu/ZnO/Al[sub 2]O[sub 3] water-gas-shift catalyst in a slurry reactor for over 400 hours. The process conditions were held constant at a temperature of 240[degrees]C, a pressure of 0.79 MPa, and a 1.1 H[sub 2]/CO feed of 0.065 Nl/min-g.cat. The Fischer-Tropsch activity remained constant at the level predicted by the operation of the Co/MgO/SiO[sub 2] catalyst alone. The water-gas-shift reaction was near equilibrium. The hydrocarbon product distribution of the combined catalyst system was stable and matched that of the CO/MgO/SiO[sub 2] operating alone under similar conditions. The combined catalyst system exhibited a high selectivity to n-alkanes. Neither catalysts's operation appeared to have a detrimental effect on that of the other, showing promise for future option.

  8. Attrition resistant catalysts for slurry-phase Fischer-Tropsch process

    SciTech Connect

    K. Jothimurugesan

    1999-11-01

    The Fischer-Tropsch (F-T) reaction provides a way of converting coal-derived synthesis gas (CO+H{sub 2}) to liquid fuels. Since the reaction is highly exothermic, one of the major problems in control of the reaction is heat removal. Recent work has shown that the use of slurry bubble column reactors (SBCRs) can largely solve this problem. Iron-based (Fe) catalysts are preferred catalysts for F-T because they are relatively inexpensive and possess reasonable activity for F-T synthesis (FTS). Their most advantages trait is their high water-gas shift (WGS) activity compared to their competitor, namely cobalt. This enables Fe F-T catalysts to process low H{sub 2}/CO ratio synthesis gas without an external shift reaction step. However, a serious problem with the use of Fe catalysts in a SBCR is their tendency to undergo attrition. This can cause fouling/plugging of downstream filters and equipment, make the separation of catalyst from the oil/wax product very difficult if not impossible, an d result in a steady loss of catalyst from the reactor. The objectives of this research were to develop a better understanding of the parameters affecting attrition of Fe F-T catalysts suitable for use in SBCRs and to incorporate this understanding into the design of novel Fe catalysts having superior attrition resistance.

  9. Development and process evaluation of improved Fischer-Tropsch slurry catalysts

    SciTech Connect

    Withers, H.P. ); Bukur, D.B.; Rosynek, M.P. )

    1988-01-01

    The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (FT) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst compositions. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.

  10. Development and process evaluation of improved Fischer-Tropsch slurry catalysts

    SciTech Connect

    Withers, H.P. ); Bukur, D.B.; Rosynek, M.P. )

    1988-01-01

    The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (F-T) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst compositions. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.

  11. Development and process evaluation of improved Fischer-Tropsch slurry catalysts

    SciTech Connect

    Withers, H.P. ); Bukur, D.B.; Rosynek, M.P. )

    1987-01-01

    The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (FT) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst compositions. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.

  12. Development of process evaluation of improved Fischer-Tropsch slurry catalysts

    SciTech Connect

    Withers, H.P. ); Bukur, D.B.; Rosynek, M.P. )

    1988-01-01

    The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (FT) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst compositions. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.

  13. Development and process evaluation of improved Fischer-Tropsch slurry catalysts

    SciTech Connect

    Withers, H.P. ); Bukur, D.B.; Rosynek, M.P. )

    1988-01-01

    The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (FT) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst comparisons. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.

  14. Fischer-Tropsch Catalysts

    NASA Technical Reports Server (NTRS)

    White, James H. (Inventor); Taylor, Jesse W. (Inventor)

    2008-01-01

    Catalyst compositions and methods for F-T synthesis which exhibit high CO conversion with minor levels (preferably less than 35% and more preferably less than 5%) or no measurable carbon dioxide generation. F-T active catalysts are prepared by reduction of certain oxygen deficient mixed metal oxides.

  15. Novel Fischer-Tropsch catalysts. [DOE patent

    DOEpatents

    Vollhardt, K.P.C.; Perkins, P.

    Novel compounds are described which are used as improved Fischer-Tropsch catalysts particularly for the conversion of CO + H/sub 2/ to gaseous and liquid hydrocarbons at milder conditions than with prior catalysts.

  16. Moderated ruthenium fischer-tropsch synthesis catalyst

    DOEpatents

    Abrevaya, Hayim

    1991-01-01

    The subject Fischer-Tropsch catalyst comprises moderated ruthenium on an inorganic oxide support. The preferred moderator is silicon. Preferably the moderator is effectively positioned in relationship to ruthenium particles through simultaneous placement on the support using reverse micelle impregnation.

  17. Novel Fischer-Tropsch catalysts

    DOEpatents

    Vollhardt, Kurt P. C.; Perkins, Patrick

    1980-01-01

    Novel polymer-supported metal complexes of the formula: PS --R Me(CO).sub.n H.sub.m where: PS represents a divinylbenzene crosslinked polystyrene in which the divinylbenzene crosslinking is greater than 1% and less than about 18%; R represents a cycloalkadienyl radical of 4 through 6 carbon atoms; Me represents a Group VIII metal; CO represents a carbonyl radical; H represents hydrogen; n represents an integer varying from 0 through 3; m represents an integer varying from 0 through 2 inclusively with the further provision that 2n+m must total 18 when added to the electrons in R and Me, or n+m must total 0; are prepared by: brominating PS --H by treating same with bromine in the presence of a thallium salt in a partially or fully halogenated solvent to form PS --Br; treating said PS --Br so produced with a lithium alkyl of 1 through 12 carbon atoms in an aromatic solvent to produce PS --Li; substituting said PS-- Li so produced by reaction with a 2-cycloalkenone of 4 to 6 carbon atoms in the presence of an ether solvent and using a water work-up to form a cycloalkenylalcohol-substituted PS ; dehydrating said alcohol so produced by heating under a vacuum to produce a cycloalkadienyl-substituted PS ; reacting the cycloalkadienyl-substituted PS with metal carbonyl in the presence of a partially or fully halogenated hydrocarbon, aromatic hydrocarbon of 6 through 8 carbon atoms, ethers, or esters of 4 through 10 carbon atoms as a solvent to produce a polystyrene-supported cycloalkadienyl metal carbonyl. The novel compounds are used as improved Fischer-Tropsch catalysts particularly for the conversion of CO+H.sub.2 to gaseous and liquid hydrocarbons at milder conditions than with prior catalysts.

  18. Novel Fischer-Tropsch catalysts

    DOEpatents

    Vollhardt, Kurt P. C.; Perkins, Patrick

    1981-01-01

    Novel polymer-supported metal complexes of the formula: PS --R Me(CO).sub.n H.sub.m where: PS represents a divinylbenzene crosslinked polystyrene in which the divinylbenzene crosslinking is greater than 1% and less than about 18%; R represents a cycloalkadienyl radical of 4 through 6 carbon atoms; Me represents a Group VIII metal; CO represents a carbonyl radical; H represents hydrogen; n represents an integer varying from 0 through 3; m represents an integer varying from 0 through 2 inclusively with the further provision that 2n+m must total 18 when added to the electrons in R and Me, or n+m must total 0; are prepared by: brominating PS --H by treating same with bromine in the presence of a thallium salt in a partially or fully halogenated solvent to form PS --Br; treating said PS --Br so produced with a lithium alkyl of 1 through 12 carbon atoms in an aromatic solvent to produce PS --Li; substituting said PS-- Li so produced by reaction with a 2-cycloalkenone of 4 to 6 carbon atoms in the presence of an ether solvent and using a water work-up to form a cycloalkenylalcohol-substituted PS ; dehydrating said alcohol so produced by heating under a vacuum to produce a cycloalkadienyl-substituted PS ; reacting the cycloalkadienyl-substituted PS with metal carbonyl in the presence of a partially or fully halogenated hydrocarbon, aromatic hydrocarbon of 6 through 8 carbon atoms, ethers, or esters of 4 through 10 carbon atoms as a solvent to produce a polystyrene-supported cycloalkadienyl metal carbonyl. The novel compounds are used as improved Fischer-Tropsch catalysts particularly for the conversion of CO+H.sub.2 to gaseous and liquid hydrocarbons at milder conditions than with prior catalysts.

  19. Novel Fischer-Tropsch catalysts

    DOEpatents

    Vollhardt, Kurt P. C.; Perkins, Patrick

    1981-01-01

    Novel polymer-supported metal complexes of the formula PS -R Me(CO).sub.n H.sub.m where: PS represents a divinylbenzene crosslinked polystyrene in which the divinylbenzene crosslinking is greater than 1% and less than about 18%; R represents a cycloalkadienyl radical of 4 through 6 carbon atoms; Me represents a Group VIII metal; CO represents a carbonyl radical; H represents hydrogen; n represents an integer varying from 0 through 3; m represents an integer varying from 0 through 2 inclusively with the further provision that 2n+m must total 18 when added to the electrons in R and Me, or n+m must total 0; are prepared by: brominating PS -H by treating same with bromine in the presence of a thallium salt in a partially or fully halogenated solvent to form PS -Br; treating said PS -Br so produced with a lithium alkyl of 1 through 12 carbon atoms in an aromatic solvent to produce PS -Li; substituting said PS - Li so produced by reaction with a 2-cycloalkenone of 4 to 6 carbon atoms in the presence of an ether solvent and using a water work-up to form a cycloalkenylalcohol-substituted PS ; dehydrating said alcohol so produced by heating under a vacuum to produce a cycloalkadienyl-substituted PS ; reacting the cycloalkadienyl-substituted PS with metal carbonyl in the presence of a partially or fully halogenated hydrocarbon, aromatic hydrocarbon of 6 through 8 carbon atoms, ethers, or esters of 4 through 10 carbon atoms as a solvent to produce a polystyrene-supported cycloalkadienyl metal carbonyl. The novel compounds are used as improved Fischer-Tropsch catalysts particularly for the conversion of CO+H.sub.2 to gaseous and liquid hydrocarbons at milder conditions than with prior catalysts.

  20. Development and process evaluation of improved Fischer-Tropsch slurry catalysts. Quarterly technical progress report, 1 July--30 September 1988

    SciTech Connect

    Withers, H.P.; Bukur, D.B.; Rosynek, M.P.

    1988-12-31

    The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (F-T) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst compositions. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.

  1. Development and process evaluation of improved Fischer-Tropsch slurry catalysts. Quarterly technical progress report, 1 October--31 December 1988

    SciTech Connect

    Withers, H.P.; Bukur, D.B.; Rosynek, M.P.

    1988-12-31

    The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (FT) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst compositions. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.

  2. Development and process evaluation of improved Fischer-Tropsch slurry catalysts. Quarterly technical progress report, 1 October-31 December 1987

    SciTech Connect

    Withers, H.P.; Bukur, D.B.; Rosynek, M.P.

    1987-12-31

    The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (FT) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst compositions. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.

  3. Development of process evaluation of improved Fischer-Tropsch slurry catalysts. Quarterly technical progress report, 1 April--30 June 1988

    SciTech Connect

    Withers, H.P.; Bukur, D.B.; Rosynek, M.P.

    1988-12-31

    The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (FT) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst compositions. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.

  4. Novel Attrition-Resistant Fischer Tropsch Catalyst

    SciTech Connect

    Weast, Logan, E.; Staats, William, R.

    2009-05-01

    There is a strong national interest in the Fischer-Tropsch synthesis process because it offers the possibility of making liquid hydrocarbon fuels from reformed natural gas or coal and biomass gasification products. This project explored a new approach that had been developed to produce active, attrition-resistant Fischer-Tropsch catalysts that are based on glass-ceramic materials and technology. This novel approach represented a promising solution to the problem of reducing or eliminating catalyst attrition and maximizing catalytic activity, thus reducing costs. The technical objective of the Phase I work was to demonstrate that glass-ceramic based catalytic materials for Fischer-Tropsch synthesis have resistance to catalytic deactivation and reduction of particle size superior to traditional supported Fischer-Tropsch catalyst materials. Additionally, these novel glass-ceramic-based materials were expected to exhibit catalytic activity similar to the traditional materials. If successfully developed, the attrition-resistant Fischer-Tropsch catalyst materials would be expected to result in significant technical, economic, and social benefits for both producers and public consumers of Fischer-Tropsch products such as liquid fuels from coal or biomass gasification. This program demonstrated the anticipated high attrition resistance of the glass-ceramic materials. However, the observed catalytic activity of the materials was not sufficient to justify further development at this time. Additional testing documented that a lack of pore volume in the glass-ceramic materials limited the amount of surface area available for catalysis and consequently limited catalytic activity. However, previous work on glass-ceramic catalysts to promote other reactions demonstrated that commercial levels of activity can be achieved, at least for those reactions. Therefore, we recommend that glass-ceramic materials be considered again as potential Fischer-Tropsch catalysts if it can be

  5. Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst. [Quarterly] report, July 1, 1990--September 30, 1990

    SciTech Connect

    Chanenchuk, C.A.; Yates, I.C.; Satterfield, C.N.

    1990-12-31

    A Co/MgO/SiO{sub 2} Fischer-Tropsch catalyst was operated simultaneously with a Cu/ZnO/Al{sub 2}O{sub 3} water-gas-shift catalyst in a slurry reactor for over 400 hours. The process conditions were held constant at a temperature of 240{degrees}C, a pressure of 0.79 MPa, and a 1.1 H{sub 2}/CO feed of 0.065 Nl/min-g.cat. The Fischer-Tropsch activity remained constant at the level predicted by the operation of the Co/MgO/SiO{sub 2} catalyst alone. The water-gas-shift reaction was near equilibrium. The hydrocarbon product distribution of the combined catalyst system was stable and matched that of the CO/MgO/SiO{sub 2} operating alone under similar conditions. The combined catalyst system exhibited a high selectivity to n-alkanes. Neither catalysts`s operation appeared to have a detrimental effect on that of the other, showing promise for future option.

  6. Cobalt Fischer-Tropsch catalysts having improved selectivity

    DOEpatents

    Miller, James G.; Rabo, Jule A.

    1989-01-01

    A cobalt Fischer-Tropsch catalyst having an improved steam treated, acid extracted LZ-210 support is taught. The new catalyst system demonstrates improved product selectivity at Fischer-Tropsch reaction conditions evidenced by lower methane production, higher C.sub.5.sup.+ yield and increased olefin production.

  7. TECHNOLOGY DEVELOPMENT FOR IRON FISCHER-TROPSCH CATALYSTS

    SciTech Connect

    Davis, B.H.

    1998-07-22

    The goal of the proposed work described in this Final Report was the development of iron-based Fischer-Tropsch catalysts that combined high activity, selectivity and life with physical robustness for slurry phase reactors that will produce either low-alpha or high-alpha products. The work described here has optimized the catalyst composition and pretreatment operation for a low-alpha catalyst. In parallel, work has been conducted to design a high-alpha iron catalyst that is suitable for slurry phase synthesis. Studies have been conducted to define the chemical phases present at various stages of the pretreatment and synthesis stages and to define the course of these changes. The oxidation/reduction cycles that are anticipated to occur in large, commercial reactors have been studied at the laboratory scale. Catalyst performance has been determined for catalysts synthesized in this program for activity, selectivity and aging characteristics.

  8. Technology development for iron Fischer-Tropsch catalysts

    SciTech Connect

    Frame, R.R.; Gala, H.B.

    1992-12-22

    Objective is to develop producing active, stable iron Fischer-Tropsch catalysts for use in slurry-phase synthesis reactors and to synthesize such catalysts on a large scale for process development and long-term testing in slurry bubble-column reactors. A mixed oxalate of Fe, Cu, and K was prepared; a catalyst will be prepared from this material. An evaluation run was performed on an Fe-based UCI catalyst, which was shown to produce low levels of C[sub 1] and C[sub 2] paraffins; e.g., at the end of the run, when the catalyst was converting 60% of the CO, the C[sub 1] and C[sub 2] paraffin selectivities were 4.2 and 1.0, respectively.

  9. KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYNTHESIS

    SciTech Connect

    Dragomir B. Bukur; Gilbert F. Froment; Lech Nowicki; Jiang Wang; Wen-Ping Ma

    2003-09-29

    This report covers the first year of this three-year research grant under the University Coal Research program. The overall objective of this project is to develop a comprehensive kinetic model for slurry phase Fischer-Tropsch synthesis on iron catalysts. This model will be validated with experimental data obtained in a stirred tank slurry reactor (STSR) over a wide range of process conditions. The model will be able to predict concentrations of all reactants and major product species (H{sup 2}O, CO{sub 2}, linear 1- and 2-olefins, and linear paraffins) as a function of reaction conditions in the STSR. During the reporting period we have completed one STSR test with precipitated iron catalyst obtained from Ruhrchemie AG (Oberhausen-Holten, Germany). This catalyst was initially in commercial fixed bed reactors at Sasol in South Africa. The catalyst was tested at 13 different sets of process conditions, and had experienced a moderate deactivation during the first 500 h of testing (decrease in conversion from 56% to 50% at baseline process conditions). The second STSR test has been initiated and after 270 h on stream, the catalyst was tested at 6 different sets of process conditions.

  10. KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYNTHESIS

    SciTech Connect

    Dragomir B. Bukur

    2004-09-29

    This report covers the second year of this three-year research grant under the University Coal Research program. The overall objective of this project is to develop a comprehensive kinetic model for slurry phase Fischer-Tropsch synthesis on iron catalysts. This model will be validated with experimental data obtained in a stirred tank slurry reactor (STSR) over a wide range of process conditions. The model will be able to predict concentrations of all reactants and major product species (H{sub 2}O, CO{sub 2}, linear 1- and 2-olefins, and linear paraffins) as a function of reaction conditions in the STSR. During the second year of the project we completed the STSR test SB-26203 (275-343 h on stream), which was initiated during the first year of the project, and another STSR test (SB-28603 lasting 341 h). Since the inception of the project we completed 3 STSR tests, and evaluated catalyst under 25 different sets of process conditions. A precipitated iron catalyst obtained from Ruhrchemie AG (Oberhausen-Holten, Germany) was used in all tests. This catalyst was used initially in commercial fixed bed reactors at Sasol in South Africa. Also, during the second year we performed a qualitative analysis of experimental data from all three STSR tests. Effects of process conditions (reaction temperature, pressure, feed composition and gas space velocity) on water-gas-shift (WGS) activity and hydrocarbon product distribution have been determined.

  11. Development and process evaluation of improved Fischer-Tropsch slurry catalysts. Sixth quarterly technical progress report, 1 January--31 March 1988

    SciTech Connect

    Withers, H.P.; Bukur, D.B.; Rosynek, M.P.

    1988-12-31

    The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (FT) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst comparisons. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.

  12. Technology development for iron Fischer-Tropsch catalysts

    SciTech Connect

    O`Brien, R.J.; Raje, A.; Keogh, R.A.

    1995-12-31

    The objective of this research project is to develop the technology for the production of physically robust iron-based Fischer-Tropsch catalysts that have suitable activity, selectivity and stability to be used in the slurry phase synthesis reactor development. The catalysts that are developed shall be suitable for testing in the Advanced Fuels Development Facility at LaPorte, Texas, to produce either low-or high-alpha product distributions. Previous work by the offeror has produced a catalyst formulation that is 1.5 times as active as the {open_quotes}standard-catalyst{close_quotes} developed by German workers for slurry phase synthesis. In parallel, work will be conducted to design a high-alpha iron catalyst this is suitable for slurry phase synthesis. Studies will be conducted to define the chemical phases present at various stages of the pretreatment and synthesis stages and to define the course of these changes. The oxidation/reduction cycles that are anticipated to occur in large, commercial reactors will be studied at the laboratory scale. Catalyst performance will be determined for catalysts synthesized in this program for activity, selectivity and aging characteristics.

  13. Cobalt Fischer-Tropsch catalysts having improved selectivity

    DOEpatents

    Miller, James G.; Rabo, Jule A.

    1989-01-01

    The promoter(s) Mn oxide or Mn oxide and Zr oxide are added to a cobalt Fischer-Tropsch catalyst combined with the molecular sieve TC-103 or TC-123 such that the resultant catalyst demonstrates improved product selectivity, stability and catalyst life. The improved selectivity is evidenced by lower methane production, higher C5+ yield and increased olefin production.

  14. Technology development for iron Fischer-Tropsch catalysts

    SciTech Connect

    Frame, R.R.

    1991-01-01

    Objectives are to develop active, stable iron Fischer-Tropsch catalysts for use in slurry-phase synthesis reactors and to develop a scaleup procedure for large-scale synthesis of such catalysts for process development and long-term testing in slurry bubble-column reactors. For a H[sub 2]-CO in molar ratio of 0.5 to 1.0, catalyst performance target is 88% CO+H[sub 2] conversion at a minimum space velocity of 2.4 NL/hr/gFe, with no more than 4% methane/ethane selectivity and 1% conversion loss per week. During this period, it was found that the performance of the slurry-phase iron and copper oxide-based catalyst depends on the amount of K. Five catalysts with differing K contents were studied. The catalysts with the lowest K were more active than the ones with higher K levels. The one with the middle K level was judged best.

  15. Improved Fischer-Tropsch Slurry Reactors

    SciTech Connect

    Andrew Lucero

    2009-03-20

    The conversion of synthesis gas to hydrocarbons or alcohols involves highly exothermic reactions. Temperature control is a critical issue in these reactors for a number of reasons. Runaway reactions can be a serious safety issue, even raising the possibility of an explosion. Catalyst deactivation rates tend to increase with temperature, particularly of there are hot spots in the reactor. For alcohol synthesis, temperature control is essential because it has a large effect on the selectivity of the catalysts toward desired products. For example, for molybdenum disulfide catalysts unwanted side products such as methane, ethane, and propane are produced in much greater quantities if the temperature increases outside an ideal range. Slurry reactors are widely regarded as an efficient design for these reactions. In a slurry reactor a solid catalyst is suspended in an inert hydrocarbon liquid, synthesis gas is sparged into the bottom of the reactor, un-reacted synthesis gas and light boiling range products are removed as a gas stream, and heavy boiling range products are removed as a liquid stream. This configuration has several positive effects for synthesis gas reactions including: essentially isothermal operation, small catalyst particles to reduce heat and mass transfer effects, capability to remove heat rapidly through liquid vaporization, and improved flexibility on catalyst design through physical mixtures in addition to use of compositions that cannot be pelletized. Disadvantages include additional mass transfer resistance, potential for significant back-mixing on both the liquid and gas phases, and bubble coalescence. In 2001 a multiyear project was proposed to develop improved FT slurry reactors. The planned focus of the work was to improve the reactors by improving mass transfer while considering heat transfer issues. During the first year of the project the work was started and several concepts were developed to prepare for bench-scale testing. Power

  16. Fischer-Tropsch synthesis process employing a moderated ruthenium catalyst

    DOEpatents

    Abrevaya, H.

    1990-07-31

    A Fischer-Tropsch type process produces hydrocarbons from carbon monoxide and hydrogen using a novel catalyst comprising moderated ruthenium on an inorganic oxide support. The preferred moderator is silicon. Preferably the moderator is effectively positioned in relationship to ruthenium particles through simultaneous placement on the support using reverse micelle impregnation. 1 fig.

  17. Fischer-Tropsch synthesis process employing a moderated ruthenium catalyst

    DOEpatents

    Abrevaya, Hayim

    1990-01-01

    A Fischer-Tropsch type process produces hydrocarbons from carbon monoxide and hydrogen using a novel catalyst comprising moderated ruthenium on an inorganic oxide support. The preferred moderator is silicon. Preferably the moderator is effectively positioned in relationship to ruthenium particles through simultaneous placement on the support using reverse micelle impregnation.

  18. ATTRITION RESISTANT IRON-BASED FISCHER-TROPSCH CATALYSTS

    SciTech Connect

    K. Jothimurugesan; James G. Goodwin, Jr.; Santosh K. Gangwal

    1999-10-01

    Fischer-Tropsch (FT) synthesis to convert syngas (CO + H{sub 2}) derived from natural gas or coal to liquid fuels and wax is a well-established technology. For low H{sub 2} to CO ratio syngas produced from CO{sub 2} reforming of natural gas or from gasification of coal, the use of Fe catalysts is attractive because of their high water gas shift activity in addition to their high FT activity. Fe catalysts are also attractive due to their low cost and low methane selectivity. Because of the highly exothermic nature of the FT reaction, there has been a recent move away from fixed-bed reactors toward the development of slurry bubble column reactors (SBCRs) that employ 30 to 90 {micro}m catalyst particles suspended in a waxy liquid for efficient heat removal. However, the use of FeFT catalysts in an SBCR has been problematic due to severe catalyst attrition resulting in fines that plug the filter employed to separate the catalyst from the waxy product. Fe catalysts can undergo attrition in SBCRs not only due to vigorous movement and collisions but also due to phase changes that occur during activation and reaction.

  19. 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.

  20. 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.

  1. Fischer-Tropsch Slurry Reactor modeling

    SciTech Connect

    Soong, Y.; Gamwo, I.K.; Harke, F.W.

    1995-12-31

    This paper reports experimental and theoretical results on hydrodynamic studies. The experiments were conducted in a hot-pressurized Slurry-Bubble Column Reactor (SBCR). It includes experimental results of Drakeol-10 oil/nitrogen/glass beads hydrodynamic study and the development of an ultrasonic technique for measuring solids concentration. A model to describe the flow behavior in reactors was developed. The hydrodynamic properties in a 10.16 cm diameter bubble column with a perforated-plate gas distributor were studied at pressures ranging from 0.1 to 1.36 MPa, and at temperatures from 20 to 200{degrees}C, using a dual hot-wire probe with nitrogen, glass beads, and Drakeol-10 oil as the gas, solid, and liquid phase, respectively. It was found that the addition of 20 oil wt% glass beads in the system has a slight effect on the average gas holdup and bubble size. A well-posed three-dimensional model for bed dynamics was developed from an ill-posed model. The new model has computed solid holdup distributions consistent with experimental observations with no artificial {open_quotes}fountain{close_quotes} as predicted by the earlier model. The model can be applied to a variety of multiphase flows of practical interest. An ultrasonic technique is being developed to measure solids concentration in a three-phase slurry reactor. Preliminary measurements have been made on slurries consisting of molten paraffin wax, glass beads, and nitrogen bubbles at 180 {degrees}C and 0.1 MPa. The data show that both the sound speed and attenuation are well-defined functions of both the solid and gas concentrations in the slurries. The results suggest possibilities to directly measure solids concentration during the operation of an autoclave reactor containing molten wax.

  2. KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYSTHESIS

    SciTech Connect

    Dragomir B. Bukur; Gilbert F. Froment; Tomasz Olewski

    2005-09-29

    This report covers the third year of this research grant under the University Coal Research program. The overall objective of this project is to develop a comprehensive kinetic model for slurry phase Fischer-Tropsch synthesis (FTS) on iron catalysts. This model will be validated with experimental data obtained in a stirred tank slurry reactor (STSR) over a wide range of process conditions. The model will be able to predict molar flow rates and concentrations of all reactants and major product species (H{sub 2}O, CO{sub 2}, linear 1- and 2-olefins, and linear paraffins) as a function of reaction conditions in the STSR. During the reporting period we utilized experimental data from the STSR, that were obtained during the first two years of the project, to perform vapor-liquid equilibrium (VLE) calculations and estimate kinetic parameters. We used a modified Peng-Robinson (PR) equation of state (EOS) with estimated values of binary interaction coefficients for the VLE calculations. Calculated vapor phase compositions were in excellent agreement with experimental values from the STSR under reaction conditions. Occasional discrepancies (for some of the experimental data) between calculated and experimental values of the liquid phase composition were ascribed to experimental errors. The VLE calculations show that the vapor and the liquid are in thermodynamic equilibrium under reaction conditions. Also, we have successfully applied the Levenberg-Marquardt method (Marquardt, 1963) to estimate parameters of a kinetic model proposed earlier by Lox and Froment (1993b) for FTS on an iron catalyst. This kinetic model is well suited for initial studies where the main goal is to learn techniques for parameter estimation and statistical analysis of estimated values of model parameters. It predicts that the chain growth parameter ({alpha}) and olefin to paraffin ratio are independent of carbon number, whereas our experimental data show that they vary with the carbon number

  3. KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYNTHESIS

    SciTech Connect

    Dragomir B. Bukur; Gilbert F. Froment; Tomasz Olewski

    2006-09-29

    This report covers the fourth year of a research project conducted under the University Coal Research Program. The overall objective of this project is to develop a comprehensive kinetic model for slurry-phase Fischer-Tropsch synthesis (FTS) employing iron-based catalysts. This model will be validated with experimental data obtained in a stirred-tank slurry reactor (STSR) over a wide range of process conditions. The model will be able to predict molar flow rates and concentrations of all reactants and major product species (water, carbon dioxide, linear 1- and 2-olefins, and linear paraffins) as a function of reaction conditions in the STSR. During the fourth year of the project, an analysis of experimental data collected during the second year of this project was performed. Kinetic parameters were estimated utilizing product distributions from 27 mass balances. During the reporting period two kinetic models were employed: a comprehensive kinetic model of Dr. Li and co-workers (Yang et al., 2003) and a hydrocarbon selectivity model of Van der Laan and Beenackers (1998, 1999) The kinetic model of Yang et al. (2003) has 24 parameters (20 parameters for hydrocarbon formation, and 4 parameters for the water-gas-shift (WGS) reaction). Kinetic parameters for the WGS reaction and FTS synthesis were estimated first separately, and then simultaneously. The estimation of these kinetic parameters employed the Levenberg-Marquardt (LM) method and the trust-region reflective Newton large-scale (LS) method. A genetic algorithm (GA) was incorporated into estimation of parameters for FTS reaction to provide initial estimates of model parameters. All reaction rate constants and activation energies were found to be positive, but at the 95% confidence level the intervals were large. Agreement between predicted and experimental reaction rates has been fair to good. Light hydrocarbons are predicted fairly accurately, whereas the model underpredicts values of higher molecular weight

  4. DEVELOPMENT OF PRECIPITATED IRON FISCHER-TROPSCH CATALYSTS

    SciTech Connect

    Dr. Dragomir B. Bukur; Dr. X. Lang; Dr. S. Chokkaram; Dr. L. Nowicki; G. Wei; Dr. Y. Ding; Dr. B. Reddy; Dr. S. Xiao

    1999-07-22

    Despite the current worldwide oil glut, the US will ultimately require large-scale production of liquid (transportation) fuels from coal. Slurry phase Fischer-Tropsch (F-T) technology, with its versatile product slate, may be expected to play a major role in production of transportation fuels via indirect coal liquefaction. Some of the F-T catalysts synthesized and tested at Texas A and M University under DOE Contract No. DE-AC22-89PC89868 were more active than any other known catalysts developed for maximizing production of high molecular weight hydrocarbons (waxes). The objectives of the present contract were to demonstrate repeatability of catalyst performance and reproducibility of preparation procedures of two of these catalysts on a laboratory scale. Improvements in the catalyst performance were attempted through the use of: (a) higher reaction pressure and gas space velocity to maximize the reactor productivity; (b) modifications in catalyst preparation steps; and (c) different pretreatment procedures. Repeatability of catalyst performance and reproducibility of catalyst synthesis procedure have been successfully demonstrated in stirred tank slurry reactor tests. Reactor space-time-yield was increased up to 48% by increasing reaction pressure from 1.48 MPa to 2.17 MPa, while maintaining the gas contact time and synthesis gas conversion at a constant value. Use of calcination temperatures above 300 C, additional CaO promoter, and/or potassium silicate as the source of potassium promoter, instead of potassium bicarbonate, did not result in improved catalyst performance. By using different catalyst activation procedures they were able to increase substantially the catalyst activity, while maintaining low methane and gaseous hydrocarbon selectivities. Catalyst productivity in runs SA-0946 and SA-2186 was 0.71 and 0.86 gHC/g-Fe/h, respectively, and this represents 45-75% improvement in productivity relative to that achieved in Rheinpreussen's demonstration plant

  5. Development of precipitated iron Fischer-Tropsch catalysts. Quarterly report, October 1, 1996--December 31, 1996

    SciTech Connect

    Bukur, D.B.

    1997-03-07

    The overall contract objectives are to: (1) demonstrate repeatability of performance and preparation procedure of two high activity, high alpha iron Fischer-Tropsch catalysts synthesized at Texas A&M University, (2) seek potential improvements in the catalyst performance through variations in process condition, pretreatment procedures and/or modification in catalyst synthesis, (3) investigate performance of catalysts in a small scale bubble column slurry reactor, and (4) investigate feasibility of producing catalysts on a large scale in collaboration with a catalyst manufacturer. Work during this period included pretreatment effect research and catalyst characterization.

  6. The role of zeolite in the Fischer-Tropsch synthesis over cobalt-zeolite catalysts

    NASA Astrophysics Data System (ADS)

    Sineva, L. V.; Asalieva, E. Yu; Mordkovich, V. Z.

    2015-11-01

    The review deals with the specifics of the Fischer-Tropsch synthesis for the one-stage syncrude production from CO and H2 in the presence of cobalt-zeolite catalytic systems. Different types of bifunctional catalysts (hybrid, composite) combining a Fischer-Tropsch catalyst and zeolite are reviewed. Special attention focuses on the mechanisms of transformations of hydrocarbons produced in the Fischer-Tropsch process on zeolite acid sites under the synthesis conditions. The bibliography includes 142 references.

  7. Supported fischer-tropsch catalyst and method of making the catalyst

    DOEpatents

    Dyer, Paul N.; Pierantozzi, Ronald; Withers, Howard P.

    1987-01-01

    A Fischer-Tropsch catalyst and a method of making the catalyst for a Fischer-Tropsch process utilizing the catalyst by which synthesis gas, particularly carbon-monoxide rich synthesis gas, is selectively converted to higher hydrocarbons of relatively narrow carbon number range is disclosed. In general, the selective and notably stable catalyst, consist of an inert carrier first treated with a Group IV B metal compound (such as zirconium or titanium), preferably an alkoxide compound, and subsequently treated with an organic compound of a Fischer-Tropsch metal catalyst, such as cobalt, iron or ruthenium carbonyl. Reactions with air and water and calcination are specifically avoided in the catalyst preparation procedure.

  8. TECHNOLOGY DEVELOPMENT FOR IRON AND COBALT FISCHER-TROPSCH CATALYSTS

    SciTech Connect

    Burtron H. Davis

    1999-01-30

    The effects of copper on Fischer-Tropsch activity, selectivity and water-gas shift activity were studied over a wide range of syngas conversion. Three catalyst compositions were prepared for this study: (a) 100Fe/4.6Si/1.4K, (b) 100Fe/4.6Si/0.10Cu/1.4K and (c) 100Fe/4.6Si/2.0Cu/1.4K. The results are reported in Task 2. The literature review for cobalt catalysts is approximately 90% complete. Due to the size of the document, it has been submitted as a separate report labeled Task 6.

  9. KINETIC MODELING OF A FISCHER-TROPSCH REACTION OVER A COBALT CATALYST IN A SLURRY BUBBLE COLUMN REACTOR FOR INCORPORATION INTO A COMPUTATIONAL MULTIPHASE FLUID DYNAMICS MODEL

    SciTech Connect

    Anastasia Gribik; Doona Guillen, PhD; Daniel Ginosar, PhD

    2008-09-01

    Currently multi-tubular fixed bed reactors, fluidized bed reactors, and slurry bubble column reactors (SBCRs) are used in commercial Fischer Tropsch (FT) synthesis. There are a number of advantages of the SBCR compared to fixed and fluidized bed reactors. The main advantage of the SBCR is that temperature control and heat recovery are more easily achieved. The SBCR is a multiphase chemical reactor where a synthesis gas, comprised mainly of H2 and CO, is bubbled through a liquid hydrocarbon wax containing solid catalyst particles to produce specialty chemicals, lubricants, or fuels. The FT synthesis reaction is the polymerization of methylene groups [-(CH2)-] forming mainly linear alkanes and alkenes, ranging from methane to high molecular weight waxes. The Idaho National Laboratory is developing a computational multiphase fluid dynamics (CMFD) model of the FT process in a SBCR. This paper discusses the incorporation of absorption and reaction kinetics into the current hydrodynamic model. A phased approach for incorporation of the reaction kinetics into a CMFD model is presented here. Initially, a simple kinetic model is coupled to the hydrodynamic model, with increasing levels of complexity added in stages. The first phase of the model includes incorporation of the absorption of gas species from both large and small bubbles into the bulk liquid phase. The driving force for the gas across the gas liquid interface into the bulk liquid is dependent upon the interfacial gas concentration in both small and large bubbles. However, because it is difficult to measure the concentration at the gas-liquid interface, coefficients for convective mass transfer have been developed for the overall driving force between the bulk concentrations in the gas and liquid phases. It is assumed that there are no temperature effects from mass transfer of the gas phases to the bulk liquid phase, since there are only small amounts of dissolved gas in the liquid phase. The product from the

  10. Synthesis gas solubility in Fischer-Tropsch slurry: Final report

    SciTech Connect

    Chao, K.C.; Lin, H.M.

    1988-01-01

    The objective is to investigate the phase equilibrium behavior of synthesis gases and products in a Fischer-Tropsch slurry reactor. A semi-flow apparatus has been designed and constructed for this purpose. Measurements have been made for hydrogen, cabon monoxide, methane, ethane, ethylene, and carbon dioxide in a heavy n-paraffin at temperatures from 100 to 300)degree)C and pressures 10 to 50 atm. Three n-paraffin waxes: n-eicosane (n-C/sub 20/), n-octacosane )n-C/sub 28/), and n-hexatriacontane (n-C/sub 36/), were studied to model the industrial wax. Solubility of synthesis gas mixtures of H/sub 2/ and CO in n-C/sub 28/ was also determined at two temperatures (200 and 300)degree)C) for each of three gas compositions (40.01, 50.01, and 66.64 mol%) of hydrogen). Measurements were extended to investigate the gas solubility in two industrial Fischer-Tropsch waxes: Mobilwax and SASOL wax. Observed solubility increases in the order: H/sub 2/, CO, CH/sub 4/, CO/sub 2/, C/sub 2/H/sub 4/, C/sub 2/H/sub 6/, at a given temperature pressure, and in the same solvent. Solubility increases with increasing pressure for all the gases. Lighter gases H/sub 2/ and CO show increased solubility with increasing temperature, while the heavier gases CO/sub 2/, ethane, and ethylene show decreased solubility with increasing temperature. The solubility of methane, the intermediate gas, changes little with temperature, and shows a shallow minimum at about 200)degrees)C or somewhat above. Henry's constant and partial molal volume of the gas solute at infinite dilution are determinedfrom the gas solubility data. A correlation is developed from the experimental data in the form on an equation of state. A computer program has been prepared to implement the correlation. 19 refs., 66 figs., 39 tabs.

  11. Kinetics of Slurry Phase Fischer-Tropsch Synthesis

    SciTech Connect

    Dragomir B. Bukur; Gilbert F. Froment; Tomasz Olewski; Lech Nowicki; Madhav Nayapati

    2006-12-31

    The overall objective of this project is to develop a comprehensive kinetic model for slurry-phase Fischer-Tropsch synthesis (FTS) employing iron-based catalysts. This model will be validated with experimental data obtained in a stirred-tank slurry reactor (STSR) over a wide range of process conditions. Three STSR tests of the Ruhrchemie LP 33/81 catalyst were conducted to collect data on catalyst activity and selectivity under 25 different sets of process conditions. The observed decrease in 1-olefin content and increase in 2-olefin and n-paraffin contents with the increase in conversion are consistent with a concept that 1-olefins participate in secondary reactions (e.g. 1-olefin hydrogenation, isomerization and readsorption), whereas 2-olefins and n-paraffins are formed in these reactions. Carbon number product distribution showed an increase in chain growth probability with increase in chain length. Vapor-liquid equilibrium calculations were made to check validity of the assumption that the gas and liquid phases are in equilibrium during FTS in the STSR. Calculated vapor phase compositions were in excellent agreement with experimental values from the STSR under reaction conditions. Discrepancies between the calculated and experimental values for the liquid-phase composition (for some of the experimental data) are ascribed to experimental errors in the amount of wax collected from the reactor, and the relative amounts of hydrocarbon wax and Durasyn 164 oil (start-up fluid) in the liquid samples. Kinetic parameters of four kinetic models (Lox and Froment, 1993b; Yang et al., 2003; Van der Laan and Beenackers, 1998, 1999; and an extended kinetic model of Van der Laan and Beenackers) were estimated from experimental data in the STSR tests. Two of these kinetic models (Lox and Froment, 1993b; Yang et al., 2003) can predict a complete product distribution (inorganic species and hydrocarbons), whereas the kinetic model of Van der Laan and Beenackers (1998, 1999) can

  12. Separation of Fischer-Tropsch Wax Products from Ultrafine Iron Catalyst Particles

    SciTech Connect

    Amitava Sarkar; James K. Neathery; Burtron H. Davis

    2006-12-31

    A fundamental filtration study was started to investigate the separation of Fischer-Tropsch Synthesis (FTS) liquids from iron-based catalyst particles. Slurry-phase FTS in slurry bubble column reactor systems is the preferred mode of operation since the reaction is highly exothermic. Consequently, heavy wax products in one approach may be separated from catalyst particles before being removed from the reactor system. Achieving an efficient wax product separation from iron-based catalysts is one of the most challenging technical problems associated with slurry-phase iron-based FTS and is a key factor for optimizing operating costs. The separation problem is further compounded by attrition of iron catalyst particles and the formation of ultra-fine particles.

  13. Iron on mixed zirconia-titania substrate Fischer-Tropsch catalyst and method of making same

    DOEpatents

    Dyer, Paul N.; Nordquist, Andrew F.; Pierantozzi, Ronald

    1986-01-01

    A Fischer-Tropsch catalyst comprising iron co-deposited with or deposited on particles comprising a mixture of zirconia and titania, preferably formed by co-precipitation of compounds convertible to zirconia and titania, such as zirconium and titanium alkoxide. The invention also comprises the method of making this catalyst and an improved Fischer-Tropsch reaction process in which the catalyst is utilized.

  14. Morphological transformation during activation and reaction of an iron Fischer-Tropsch catalyst

    SciTech Connect

    Jackson, N.B.; Kohler, S.; Harrington, M.

    1995-12-31

    The purpose of this project is to support the development of slurry-phase bubble column processes being studied at the La Porte Alternative Fuel Development Unit. This paper describes the aspects of Sandia`s recent work regarding the advancement and understanding of the iron catalyst used in the slurry phase process. A number of techniques were used to understand the chemical and physical effects of pretreatment and reaction on the attrition and carbon deposition characteristics of iron catalysts. Unless otherwise stated, the data discussed was derived form experiments carried out on the catalyst chosen for the summer 1994 Fischer-Tropsch run at LaPorte, UCI 1185-78-370, (an L 3950 type) that is 88% Fe{sub 2}O{sub 3}, 11% CuO, and 0.052%K{sub 2}O.

  15. Improved Fischer-Tropsch catalysts for indirect coal liquefaction

    SciTech Connect

    Wilson, R.B. Jr.; Tong, G.T.; Chan, Y.W.; Huang, H.W.; McCarty, J.G.

    1989-02-01

    The Fischer-Tropsch synthesis (FTS)reaction is the established technology for the production of liquid fuels from coal by an indirect route using coal-derived syngas (CO + H{sub 2}). Modern FTS catalysts are potassium- and copper-promoted iron preparations. These catalysts exhibit moderate activity with carbon monoxide-rich feedstocks such as the syngas produced by advanced coal gasification processes. However, the relatively large yields of by-product methane and high-molecular-weight hydrocarbon waxes detract from the production of desired liquid products in the C{sub 5}-C{sub 16} range needed for motor and aviation fuel. The goal of this program is to decrease undesirable portions of the FTS hydrocarbon yield by altering the Schultz-Flory polymerization product distribution through design and formulation of improved catalysts. Two approaches were taken: (1) reducing the yield of high-molecular-weight hydrocarbon waxes by using highly dispersed catalysts produced from surface-confined multiatomic clusters on acid supports and (2) suppressing methane production by uniformly pretreating active, selective conventional FTS catalysts with submonolayer levels of sulfur.

  16. Chemical imaging of Fischer-Tropsch catalysts under operating conditions

    PubMed Central

    Price, Stephen W. T.; Martin, David J.; Parsons, Aaron D.; Sławiński, Wojciech A.; Vamvakeros, Antonios; Keylock, Stephen J.; Beale, Andrew M.; Mosselmans, J. Frederick W.

    2017-01-01

    Although we often understand empirically what constitutes an active catalyst, there is still much to be understood fundamentally about how catalytic performance is influenced by formulation. Catalysts are often designed to have a microstructure and nanostructure that can influence performance but that is rarely considered when correlating structure with function. Fischer-Tropsch synthesis (FTS) is a well-known and potentially sustainable technology for converting synthetic natural gas (“syngas”: CO + H2) into functional hydrocarbons, such as sulfur- and aromatic-free fuel and high-value wax products. FTS catalysts typically contain Co or Fe nanoparticles, which are often optimized in terms of size/composition for a particular catalytic performance. We use a novel, “multimodal” tomographic approach to studying active Co-based catalysts under operando conditions, revealing how a simple parameter, such as the order of addition of metal precursors and promoters, affects the spatial distribution of the elements as well as their physicochemical properties, that is, crystalline phase and crystallite size during catalyst activation and operation. We show in particular how the order of addition affects the crystallinity of the TiO2 anatase phase, which in turn leads to the formation of highly intergrown cubic close-packed/hexagonal close-packed Co nanoparticles that are very reactive, exhibiting high CO conversion. This work highlights the importance of operando microtomography to understand the evolution of chemical species and their spatial distribution before any concrete understanding of impact on catalytic performance can be realized. PMID:28345057

  17. Chemical imaging of Fischer-Tropsch catalysts under operating conditions.

    PubMed

    Price, Stephen W T; Martin, David J; Parsons, Aaron D; Sławiński, Wojciech A; Vamvakeros, Antonios; Keylock, Stephen J; Beale, Andrew M; Mosselmans, J Frederick W

    2017-03-01

    Although we often understand empirically what constitutes an active catalyst, there is still much to be understood fundamentally about how catalytic performance is influenced by formulation. Catalysts are often designed to have a microstructure and nanostructure that can influence performance but that is rarely considered when correlating structure with function. Fischer-Tropsch synthesis (FTS) is a well-known and potentially sustainable technology for converting synthetic natural gas ("syngas": CO + H2) into functional hydrocarbons, such as sulfur- and aromatic-free fuel and high-value wax products. FTS catalysts typically contain Co or Fe nanoparticles, which are often optimized in terms of size/composition for a particular catalytic performance. We use a novel, "multimodal" tomographic approach to studying active Co-based catalysts under operando conditions, revealing how a simple parameter, such as the order of addition of metal precursors and promoters, affects the spatial distribution of the elements as well as their physicochemical properties, that is, crystalline phase and crystallite size during catalyst activation and operation. We show in particular how the order of addition affects the crystallinity of the TiO2 anatase phase, which in turn leads to the formation of highly intergrown cubic close-packed/hexagonal close-packed Co nanoparticles that are very reactive, exhibiting high CO conversion. This work highlights the importance of operando microtomography to understand the evolution of chemical species and their spatial distribution before any concrete understanding of impact on catalytic performance can be realized.

  18. Development of precipitated iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 April 1996--30 June 1996

    SciTech Connect

    Bukur, D.B.; Lang, X.; Ding, Y.; Chokkaram, S.

    1996-09-02

    The overall contract objectives are to: (1) demonstrate repeatability of performance and preparation procedure of two high activity, high alpha iron Fischer-Tropsch catalysts synthesized at Texas A&M University (TAMU) during the DOE Contract DE-AC22-89PC89868; (2) seek potential improvements in the catalyst performance through variations in process conditions, pretreatment procedures and/or modifications in catalyst synthesis; (3) investigate performance of catalysts in a small scale bubble column slurry reactor, and (4) investigate feasibility of producing catalysts on a large scale in collaboration with a catalyst manufacturer. The performance of an iron, and iron-copper-silica catalyst are described.

  19. Development of precipitated iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 January 1996--31 March 1996

    SciTech Connect

    Bukur, D.B.

    1996-06-03

    The overall contract objectives are to: (1) demonstrate repeatability of performance and preparation procedure of two high activity, high alpha iron Fischer-Tropsch catalysts synthesized at Texas A&M University (TAMU); (2) seek potential improvements in the catalyst performance through variations in process conditions, pretreatment procedures and/or modifications in catalyst synthesis; (3) investigate performance of catalysts in a small scale bubble column slurry reactor, and (4) investigate feasibility of producing catalysts on a large scale in collaboration with a catalyst manufacturer. In order to achieve these objectives the work is divided into ten tasks, which are described and their accomplishments are reported.

  20. SEPARATION OF FISCHER-TROPSCH WAX PRODUCTS FROM ULTRAFINE IRON CATALYST PARTICLES

    SciTech Connect

    James K. Neathery; Gary Jacobs; Burtron H. Davis

    2004-03-31

    In this reporting period, a fundamental filtration study was started to investigate the separation of Fischer-Tropsch Synthesis (FTS) liquids from iron-based catalyst particles. Slurry-phase FTS in slurry bubble column reactor systems is the preferred mode of production since the reaction is highly exothermic. Consequently, heavy wax products must be separated from catalyst particles before being removed from the reactor system. Achieving an efficient wax product separation from iron-based catalysts is one of the most challenging technical problems associated with slurry-phase FTS. The separation problem is further compounded by catalyst particle attrition and the formation of ultra-fine iron carbide and/or carbon particles. Existing pilot-scale equipment was modified to include a filtration test apparatus. After undergoing an extensive plant shakedown period, filtration tests with cross-flow filter modules using simulant FTS wax slurry were conducted. The focus of these early tests was to find adequate mixtures of polyethylene wax to simulate FTS wax. Catalyst particle size analysis techniques were also developed. Initial analyses of the slurry and filter permeate particles will be used by the research team to design improved filter media and cleaning strategies.

  1. Fly ash zeolite catalyst support for Fischer-Tropsch synthesis

    NASA Astrophysics Data System (ADS)

    Campen, Adam

    This dissertation research aimed at evaluating a fly ash zeolite (FAZ) catalyst support for use in heterogeneous catalytic processes. Gas phase Fischer-Tropsch Synthesis (FTS) over a fixed-bed of the prepared catalyst/FAZ support was identified as an appropriate process for evaluation, by comparison with commercial catalyst supports (silica, alumina, and 13X). Fly ash, obtained from the Wabash River Generating Station, was first characterized using XRD, SEM/EDS, particle size, and nitrogen sorption techniques. Then, a parametric study of a two-step alkali fusion/hydrothermal treatment process for converting fly ash to zeolite frameworks was performed by varying the alkali fusion agent, agent:flyash ratio, fusion temperature, fused ash/water solution, aging time, and crystallization time. The optimal conditions for each were determined to be NaOH, 1.4 g NaOH: 1 g fly ash, 550 °C, 200 g/L, 12 hours, and 48 hours. This robust process was applied to the fly ash to obtain a faujasitic zeolite structure with increased crystallinity (40 %) and surface area (434 m2/g). Following the modification of fly ash to FAZ, ion exchange of H+ for Na+ and cobalt incipient wetness impregnation were used to prepare a FTS catalyst. FTS was performed on the catalysts at 250--300 °C, 300 psi, and with a syngas ratio H2:CO = 2. The HFAZ catalyst support loaded with 11 wt% cobalt resulted in a 75 % carbon selectivity for C5 -- C18 hydrocarbons, while methane and carbon dioxide were limited to 13 and 1 %, respectively. Catalyst characterization was performed by XRD, N2 sorption, TPR, and oxygen pulse titration to provide insight to the behavior of each catalyst. Overall, the HFAZ compared well with silica and 13X supports, and far exceeded the performance of the alumina support under the tested conditions. The successful completion of this research could add value to an underutilized waste product of coal combustion, in the form of catalyst supports in heterogeneous catalytic processes.

  2. Influence of liquid medium on the activity of a low-alpha Fischer-Tropsch catalyst

    SciTech Connect

    Gormley, R.J.; Zarochak, M.F.; Deffenbaugh, P.W.; Rao, K.R.P.M.

    1995-12-31

    The purpose of this research was to measure activity, selectivity, and the maintenance of these properties in slurry autoclave experiments with a Fischer-Tropsch (FT) catalyst that was used in the {open_quotes}FT II{close_quotes} bubble-column test, conducted at the Alternative Fuels Development Unit (AFDU) at LaPorte, Texas during May 1994. The catalyst contained iron, copper, and potassium and was formulated to produce mainly hydrocarbons in the gasoline range with lesser production of diesel-range products and wax. The probability of chain growth was thus deliberately kept low. Principal goals of the autoclave work have been to find the true activity of this catalyst in a stirred tank reactor, unhindered by heat or mass transfer effects, and to obtain a steady conversion and selectivity over the approximately 15 days of each test. Slurry autoclave testing of the catalyst in heavier waxes also allows insight into operation of larger slurry bubble column reactors. The stability of reactor operation in these experiments, particularly at loadings exceeding 20 weight %, suggests the likely stability of operations on a larger scale.

  3. Development of precipitated iron Fischer-Tropsch catalysts. Quarterly technical progress report, April 1, 1995--June 30, 1995

    SciTech Connect

    Bukur, D.B.; Lang, X.; Wei, G.; Xiao, S.

    1995-08-17

    Work continued on the development of catalysts for Fischer-Tropsch synthesis. Six catalysts were synthesised. The effects of a calcium oxide promoter were evaluated. Catalysts were characterized for pore size and BET surface area.

  4. Separation of Fischer-Tropsch Wax Products from Ultrafine Iron Catalyst Particles

    SciTech Connect

    James K. Neathery; Gary Jacobs; Amitava Sarkar; Burtron H. Davis

    2005-09-30

    In this reporting period, a study of ultra-fine iron catalyst filtration was initiated to study the behavior of ultra-fine particles during the separation of Fischer-Tropsch Synthesis (FTS) liquids filtration. The overall focus of the program is with slurry-phase FTS in slurry bubble column reactor systems. Hydrocarbon products must be separated from catalyst particles before being removed from the reactor system. An efficient wax product/catalyst separation system is a key factor for optimizing operating costs for iron-based slurry-phase FTS. Previous work has focused on catalyst particle attrition and the formation of ultra-fine iron carbide and/or carbon particles. With the current study, we are investigating how the filtration properties are affected by these chemical and physical changes of the catalyst slurry during activation/synthesis. The change of particle size during the slurry-phase FTS has monitored by withdrawing catalyst sample at different TOS. The measurement of dimension of the HRTEM images of samples showed a tremendous growth of the particles. Carbon rims of thickness 3-6 nm around the particles were observed. This growth in particle size was not due to carbon deposition on the catalyst. A conceptual design and operating philosophy was developed for an integrated wax filtration system for a 4 liter slurry bubble column reactor to be used in Phase II of this research program. The system will utilize a primary inertial hydroclone followed by a Pall Accusep cross-flow membrane. Provisions for cleaned permeate back-pulsing will be included to as a flux maintenance measure.

  5. SEPARATION OF FISCHER-TROPSCH WAX PRODUCTS FROM ULTRAFINE IRON CATALYST PARTICLES

    SciTech Connect

    James K. Neathery; Gary Jacobs; Burtron H. Davis

    2005-03-31

    In this reporting period, a fundamental filtration study was continued to investigate the separation of Fischer-Tropsch Synthesis (FTS) liquids from iron-based catalyst particles. The overall focus of the program is with slurry-phase FTS in slurry bubble column reactor systems. Hydrocarbon products must be separated from catalyst particles before being removed from the reactor system. An efficient wax product/catalyst separation system is a key factor for optimizing operating costs for iron-based slurry-phase FTS. Previous work has focused on catalyst particle attrition and the formation of ultra-fine iron carbide and/or carbon particles. With the current study, we are investigating how the filtration properties are affected by these chemical and physical changes of the catalyst slurry during activation/synthesis. In this reporting period, a series of crossflow filtration experiments were initiated to study the effect of olefins and oxygenates on the filtration flux and membrane performance. Iron-based FTS reactor waxes contain a significant amount of oxygenates, depending on the catalyst formulation and operating conditions. Mono-olefins and aliphatic alcohols were doped into an activated iron catalyst slurry (with Polywax) to test their influence on filtration properties. The olefins were varied from 5 to 25 wt% and oxygenates from 6 to 17 wt% to simulate a range of reactor slurries reported in the literature. The addition of an alcohol (1-dodecanol) was found to decrease the permeation rate while the olefin added (1-hexadecene) had no effect on the permeation rate. A passive flux maintenance technique was tested that can temporarily increase the permeate rate for 24 hours.

  6. SEPARATION OF FISCHER-TROPSCH WAX PRODUCTS FROM ULTRAFINE IRON CATALYST PARTICLES

    SciTech Connect

    James K. Neathery; Gary Jacobs; Burtron H. Davis

    2004-09-30

    In this reporting period, a fundamental filtration study was continued to investigate the separation of Fischer-Tropsch Synthesis (FTS) liquids from iron-based catalyst particles. The overall focus of the program is with slurry-phase FTS in slurry bubble column reactor systems. Hydrocarbon products must be separated from catalyst particles before being removed from the reactor system. An efficient wax product/catalyst separation system is a key factor for optimizing operating costs for iron-based slurry-phase FTS. Previous work has focused on catalyst particle attrition and the formation of ultra-fine iron carbide and/or carbon particles. With the current study, we are investigating how the filtration properties are affected by these chemical and physical changes of the catalyst slurry during activation/synthesis. The shakedown phase of the pilot-scale filtration platform was completed at the end of the last reporting period. A study of various molecular weight waxes was initiated to determine the effect of wax physical properties on the permeation rate without catalyst present. As expected, the permeation flux was inversely proportional to the nominal average molecular weight of the polyethylene wax. Even without catalyst particles present in the filtrate, the filtration membranes experience fouling during an induction period on the order of days on-line. Another long-term filtration test was initiated using a batch of iron catalyst that was previously activated with CO to form iron carbide in a separate continuous stirred tank reactor (CSTR) system. The permeation flux stabilized more rapidly than that experienced with unactivated catalyst tests.

  7. Development of improved iron Fischer-Tropsch catalysts. Final technical report: Project 6464

    SciTech Connect

    Bukur, D.B.; Ledakowicz, S.; Koranne, M.

    1994-02-28

    Despite the current worldwide oil glut, the United States will ultimately require large-scale production of liquid (transportation) fuels from coal. Slurry phase Fischer Tropsch (FT) technology, with its versatile product slate, may be expected to play a major role in production of transportation fuels via indirect coal liquefaction. Texas A&M University (TAMU) with sponsorship from the US Department of Energy, Center for Energy and Mineral Resources at TAMU, Texas Higher Education Coordinating Board, and Air Products and Chemicals, Inc., has been working on development of improved iron FT catalysts and characterization of hydrodynamic parameters in two- and three-phase bubble columns with FT derived waxes. Our previous studies have provided an improved understanding of the role of promoters (Cu and K), binders (silica) and pretreatment procedures on catalyst activity, selectivity and longevity (deactivation). The objective of the present contract was to develop improved catalysts with enhanced slurry phase activity and higher selectivity to liquid fuels and wax. This was accomplished through systematic studies of the effects of pretreatment procedures and variations in catalyst composition (promoters and binders). The major accomplishments and results in each of these two main areas of research are summarized here.

  8. Highly active and stable iron Fischer-Tropsch catalyst for synthesis gas conversion to liquid fuels

    SciTech Connect

    Bukur, D.B.; Lang, X.

    1999-09-01

    A precipitated iron Fischer-Tropsch (F-T) catalyst (100 Fe/3 Cu/4 K/16 SiO{sub 2} on mass basis) was tested in a stirred tank slurry reactor under reaction conditions representative of industrial practice using CO-rich synthesis gas (260 C, 1.5--2.2 MPa, H{sub 2}/CO = 2/3). Repeatability of performance and reproducibility of catalyst preparation procedure were successfully demonstrated on a laboratory scale. Catalyst productivity was increased by operating at higher synthesis pressure while maintaining a constant contact time in the reactor and through the use of different catalyst pretreatment procedures. In one of the tests (run SA-2186), the catalyst productivity was 0.86 (g hydrocarbons/g Fe/h) at syngas conversion of 79%, methane selectivity of 3% (weight percent of total hydrocarbons produced), and C{sub 5}+ hydrocarbon selectivity of 83 wt %. This represents a substantial improvement in productivity in comparison to state-of-the-art iron F-T catalysts. This catalyst is ideally suited for production of high-quality diesel fuels and C{sub 2}-c{sub 4} olefins from a coal-derived synthesis gas.

  9. Technology development for iron Fischer-Tropsch catalysts. Technical progress report No. 5, September 26, 1991--December 26, 1991

    SciTech Connect

    Frame, R.R.; Gala, H.B.

    1992-12-22

    Objective is to develop producing active, stable iron Fischer-Tropsch catalysts for use in slurry-phase synthesis reactors and to synthesize such catalysts on a large scale for process development and long-term testing in slurry bubble-column reactors. A mixed oxalate of Fe, Cu, and K was prepared; a catalyst will be prepared from this material. An evaluation run was performed on an Fe-based UCI catalyst, which was shown to produce low levels of C{sub 1} and C{sub 2} paraffins; e.g., at the end of the run, when the catalyst was converting 60% of the CO, the C{sub 1} and C{sub 2} paraffin selectivities were 4.2 and 1.0, respectively.

  10. Technology development for iron Fischer-Tropsch catalysts. Technical progress report No. 11, March 26, 1993--June 26, 1993

    SciTech Connect

    Frame, R.R.; Gala, H.B.

    1994-05-01

    The objectives of this contract are to develop a technology for the production of active and stable iron (Fe) Fischer-Tropsch catalysts for use in slurry-phase synthesis reactors and to develop a scaleup procedure for large-scale synthesis of such catalysts for process development and long-term testing in slurry bubble-column reactors. With a feed containing hydrogen (H{sub 2}) and carbon monoxide (CO) in the molar ratio of 0.5 to 1.0 to the slurry bubble-column reactor, the catalyst performance target is 88% CO+H{sub 2} conversion at a minimum space velocity of 2.4 NL/hr/g Fe. The desired sum of methane and ethane selectivities is no more than 4%, and the conversion loss per week is not to exceed 1%.

  11. Heat transfer and bubble dynamics in slurry bubble columns for Fischer-Tropsch clean alternative energy

    NASA Astrophysics Data System (ADS)

    Wu, Chengtian

    With the increasing demand for alternative energy resources, the Fischer-Tropsch (FT) process that converts synthesis gas into clean liquid fuels has attracted more interest from the industry. Slurry bubble columns are the most promising reactors for FT synthesis due to their advantages over other reactors. Successful operation, design, and scale-up of such reactors require detailed knowledge of hydrodynamics, bubble dynamics, and transport characteristics. However, most previous studies have been conducted at ambient pressure or covered only low superficial gas velocities. The objectives of this study were to experimentally investigate the heat transfer coefficient and bubble dynamics in slurry bubble columns at conditions that can mimic FT conditions. The air-C9C 11-FT catalysts/glass beads systems were selected to mimic the physical properties of the gas, liquid, and solid phases at commercial FT operating conditions. A heat transfer coefficient measurement technique was developed, and for the first time, this technique was applied in a pilot scale (6-inch diameter) high pressure slurry bubble column. The effects of superficial gas velocity, pressure, solids loading, and liquid properties on the heat transfer coefficients were investigated. Since the heat transfer coefficient can be affected by the bubble properties (Kumar et al., 1992), in this work bubble dynamics (local gas holdup, bubble chord length, apparent bubble frequency, specific interfacial area, and bubble velocity) were studied using the improved four-point optical probe technique (Xue et al., 2003; Xue, 2004). Because the four-point optical technique had only been successfully applied in a churn turbulent flow bubble column (Xue, 2004), this technique was first assessed in a small scale slurry bubble column in this study. Then the bubble dynamics were studied at the same conditions as the heat transfer coefficient investigation in the same pilot scale column. The results from four-point probe

  12. Development of improved iron Fischer-Tropsch catalysts

    SciTech Connect

    Bukur, D.B.

    1992-01-10

    The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.

  13. Development of improved iron Fischer-Tropsch catalysts

    SciTech Connect

    Bukur, D.B.

    1990-06-17

    The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.

  14. Development of improved iron Fischer-Tropsch catalysts

    SciTech Connect

    Bukur, D.B.; Patel, S.A.; Dalai, A.K.; Jayanthi, G.; Ledakowicz, S.

    1990-04-30

    The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.

  15. PROGRESS TOWARDS MODELING OF FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR

    SciTech Connect

    Donna Post Guillen; Tami Grimmett; Anastasia M. Gandrik; Steven P. Antal

    2010-11-01

    The Hybrid Energy Systems Testing (HYTEST) Laboratory is being established at the Idaho National Laboratory to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions will be performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. SBCRs are cylindrical vessels in which gaseous reactants (for example, synthesis gas or syngas) is sparged into a slurry of liquid reaction products and finely dispersed catalyst particles. The catalyst particles are suspended in the slurry by the rising gas bubbles and serve to promote the chemical reaction that converts syngas to a spectrum of longer chain hydrocarbon products, which can be upgraded to gasoline, diesel or jet fuel. These SBCRs operate in the churn-turbulent flow regime which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer, that effect reactor performance. The purpose of this work is to develop a computational multiphase fluid dynamic (CMFD) model to aid in understanding the physico-chemical processes occurring in the SBCR. Our team is developing a robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) that includes twelve species: (1) CO reactant, (2) H2 reactant, (3) hydrocarbon product, and (4) H2O product in small bubbles, large bubbles, and the bulk fluid. Properties of the hydrocarbon product were specified by vapor liquid equilibrium calculations. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is determined based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield [1]. The

  16. An exploratory program for using hydrous metal oxide ion exchangers as Fischer-Tropsch catalysts

    SciTech Connect

    Lynch, A.W.; Dosch, R.G.; Sault, A.G.

    1990-01-01

    The purpose of this program is to investigate the potential of hydrous metal oxide (HMO) ion exchangers, invented at Sandia National Laboratories, as Fischer-Tropsch (F-T) catalysts. Metals known to be active in F-T synthesis (e.g. Fe, Co) were ion exchanged on hydrous metal oxide supports. Although HMO catalysts based on Zr, Nb, and Ta have been investigated in direct coal liquefaction studies, this effect focused on formulations based on the hydrous titanium oxide (HTO) system. The program has the goals of developing a catalyst with (1) high activity, (2) selectively to fuel range or other useful products, and (3) better properties for use in slurry reactors. The program has three main tasks: (1) catalyst synthesis, to develop methods for preparing catalysts having desirable F-T properties, (2) characterization, to investigate catalysts proving to have desirable properties by a variety of analytical techniques to determine correlations between activity and material properties and (3) testing to determine activity and selectivity of catalysts. This paper discussed results of activity testing of Ruhrchemie catalyst and some catalyst formulations prepared using ion exchange on hydrous titanium oxide and precipitation. For example, at 250{degree}C the Ruhrchemie catalyst converts {approximately}50% of the syngas feed to reaction products. In comparison, iron catalysts prepared by ion exchange and precipitation had conversions ranging from 20 to 50% over a temperature range of 250 to 275{degree}C of the syngas feed. In addition, results are Auger surface analysis of Ruhrchemie catalyst are presented. 6 refs., 2 figs., 2 tabs.

  17. Fischer-Tropsch catalysts for the production of hydrocarbon fuels with high selectivity.

    PubMed

    Zhang, Qinghong; Cheng, Kang; Kang, Jincan; Deng, Weiping; Wang, Ye

    2014-05-01

    Fischer-Tropsch synthesis is a key reaction in the utilization of non-petroleum carbon resources, such as methane (natural gas, shale gas, and biogas), coal, and biomass, for the sustainable production of clean liquid fuels from synthesis gas. Selectivity control is one of the biggest challenges in Fischer-Tropsch synthesis. This Minireview focuses on the development of new catalysts with controllable product selectivities. Recent attempts to increase the selectivity to C5+ hydrocarbons by preparing catalysts with well-defined active phases or with new supports or by optimizing the interaction between the promoter and the active phase are briefly highlighted. Advances in developing bifunctional catalysts capable of catalyzing both CO hydrogenation to heavier hydrocarbons and hydrocracking/isomerization of heavier hydrocarbons are critically reviewed. It is demonstrated that the control of the secondary hydrocracking reactions by using core-shell nanostructures or solid-acid materials, such as mesoporous zeolites and carbon nanotubes with acid functional groups, is an effective strategy to tune the product selectivity of Fischer-Tropsch synthesis. Very promising selectivities to gasoline- and diesel-range hydrocarbons have been attained over some bifunctional catalysts.

  18. Catalyst nano-particle size dependence of the Fischer-Tropsch reaction.

    PubMed

    van Santen, Rutger A; Markvoor, Albert J

    2013-01-01

    Computational catalytic studies indicate that the elementary reactions that constitute the Fischer-Tropsch reaction strongly dependent on the structure of the catalyst reaction center. Recent experimental evidence is available that, for metallic Fischer-Tropsch catalysts such as Co or Ru, the very small metallic particles show altered catalytic performance. To distinguish between changes in the relative concentration of reaction centres, changes in chemical reactivity, or rate controlling steps, transient SSITKA data are extremely useful. Here, we present kinetics simulations to extract molecular kinetic information from SSITKA data. We have applied such simulations to interpret published experimental SSITKA data on nano-particle size dependent Fischer-Tropsch (FT) kinetics. The FT catalytic cycle consists of four essential reaction steps. Their relative size determines activity as well as selectivity. The simulated SSITKA indicate three different regimes with different kinetic behaviour, where the two fundamental regimes to distinguish are the monomer-formation-limited and the chain-growth-limited regime. Particle size changes shift kinetics from one to the other regime. We note different effects of supports and choice of metal composition on changes in elementary rates or the relative number of reactive centres when the particle size is decreased in the nanometre regime.

  19. Fischer-Tropsch process

    DOEpatents

    Dyer, Paul N.; Pierantozzi, Ronald; Withers, Howard P.

    1987-01-01

    A Fischer-Tropsch process utilizing a product selective and stable catalyst by which synthesis gas, particularly carbon-monoxide rich synthesis gas is selectively converted to higher hydrocarbons of relatively narrow carbon number range is disclosed. In general, the selective and notably stable catalyst, consist of an inert carrier first treated with a Group IV B metal compound (such as zirconium or titanium), preferably an alkoxide compound, and subsequently treated with an organic compound of a Fischer-Tropsch metal catalyst, such as cobalt, iron or ruthenium carbonyl. Reactions with air and water and calcination are specifically avoided in the catalyst preparation procedure.

  20. Technology development for iron Fischer-Tropsch catalysts. Technical progress report No. 9, September 26, 1992--December 26, 1992

    SciTech Connect

    Frame, R.R.; Gala, H.B.

    1992-12-31

    The objectives of this contract are to develop a technology for the production of active and stable iron Fischer-Tropsch catalysts for use in slurry-phase synthesis reactors and to develop a scaleup procedure for large-scale synthesis of such catalysts for process development and long-term testing in slurry bubble-column reactors. With a feed containing hydrogen and carbon monoxide in the molar ratio of 0.5 to 1.0 to the slurry bubble-column reactor, the catalyst performance target is 88% CO + H{sub 2} conversion at a minimum space velocity of 2.4 NL/hr/gFe. The desired sum of methane and ethane selectivities is no more than 4%, and the conversion loss per week is not to exceed 1%. Contract Tasks are as follows: 1.0--Catalyst development, 1.1--Technology assessment, 1.2--Precipitated catalyst preparation method development, 1.3--Novel catalyst preparation methods investigation, 1.4--Catalyst pretreatment, 1.5--Catalyst characterization, 2.0--Catalyst testing, 3.0--Catalyst aging studies, and 4.0--Preliminary design and cost estimate of a catalyst synthesis facility. This paper reports progress on Task 1.3.

  1. The role of catalyst activation on the activity and attrition of precipitated iron Fischer-Tropsch catalysts

    SciTech Connect

    Datye, A.K.; Shroff, M.D.; Harrington, M.S.; Coulter, K.E.; Sault, A.G.; Jackson, N.B.

    1995-12-31

    The results of this work indicate that magnetite is not catalytically active for Fischer-Tropsch Synthesis (FTS) in precipitated, unsupported iron catalysts, but the formation of the carbide phase is necessary to obtain FTS activity. The transformation of magnetite to carbide, though essential to obtain FTS activity, also causes the catalyst to break down. This can lead to severe problems during operation in a commercial slurry phase reactor. The results presented here imply that activation and attrition are simultaneous and complementary processes. In another study, we show that the catalyst can also under go attrition on a micron scale which is caused by lack of strength of the forces binding the catalyst primary particles in the agglomerates. Both these processes can make wax separation and product recovery extremely difficult. In this study, we have also shown that H{sub 2} reduction of this catalyst to metallic iron is detrimental to subsequent catalyst activity and causes a loss of surface area due to sintering of the iron crystallites. Reduction to metallic Fe also causes impurities such as S to segregate to the surface causing a complete loss of FTS activity. It has been shown that even submonolayer amounts of S can cause a dramatic decrease in FTS activity, hence reduction to metallic Fe should be avoided during activation of these catalysts. We have shown, however, that a mild H{sub 2} reduction to magnetite does not lead to S segregation to the surface, and is therefore acceptable.

  2. Mathematical modeling of Fischer-Tropsch synthesis in an industrial slurry bubble column - article no. A 23

    SciTech Connect

    Nasim Hooshyar; Shohreh Fatemi; Mohammad Rahmani

    2009-07-01

    The increase in society's need for fuels and decrease in crude oil resources are important reasons to make more interest for both academic and industry in converting gas to liquids. Fischer-Tropsch synthesis is one of the most attractive methods of Gas-to-Liquids (GTL) processes and the reactor in which, this reaction occurs, is the heart of this process. This work deals with modeling of a commercial size slurry bubble column reactor by two different models, i.e. single bubble class model (SBCM) and double bubble class model (DBCM). The reactor is assumed to work in a churn-turbulent flow regime and the reaction kinetic is a Langmuir-Hinshelwood type. Cobalt-based catalyst is used for this study as it plays an important role in preparing heavy cuts and the higher yield of the liquid products. Parameter sensitivity analysis was carried out for different conditions such as catalyst concentration, superficial gas velocity, H{sub 2} over CO ratio, and column diameter. The results of the SBCM and DBCM revealed that there is no significant difference between single and double bubble class models in terms of temperature, concentration and conversion profiles in the reactor, so the simpler SBCM with less number of model parameters can be a good and reliable model of choice for analyzing the slurry bubble column reactors.

  3. Technology development for iron Fischer-Tropsch catalysts. Technical progress report No. 4, June 26, 1991--September 26, 1991

    SciTech Connect

    Frame, R.R.

    1991-12-31

    Objectives are to develop active, stable iron Fischer-Tropsch catalysts for use in slurry-phase synthesis reactors and to develop a scaleup procedure for large-scale synthesis of such catalysts for process development and long-term testing in slurry bubble-column reactors. For a H{sub 2}-CO in molar ratio of 0.5 to 1.0, catalyst performance target is 88% CO+H{sub 2} conversion at a minimum space velocity of 2.4 NL/hr/gFe, with no more than 4% methane/ethane selectivity and 1% conversion loss per week. During this period, it was found that the performance of the slurry-phase iron and copper oxide-based catalyst depends on the amount of K. Five catalysts with differing K contents were studied. The catalysts with the lowest K were more active than the ones with higher K levels. The one with the middle K level was judged best.

  4. Nano-sized cobalt based Fischer-Tropsch catalysts for gas-to-liquid process applications.

    PubMed

    Kang, Jung Shik; Awate, S V; Lee, Yun Ju; Kim, So Jung; Park, Moon Ju; Lee, Sang Deuk; Hong, Suk-In; Moon, Dong Ju

    2010-05-01

    Nano-sized cobalt supported catalysts were prepared for Fischer-Tropsch synthesis in gas-to-liquid (GTL) process. The dependence of crystallite size and reducibility of Co3O4 on the supports were investigated with FTS activity. XRD peaks revealed nano crystallites (< 5.47 nm) of Co3O4 crystallites. TEM showed round shaped particles with size less than 5 nm. Support with higher acidity decreased crystallite size of Co3O4. XRD data of used catalysts showed Co3O4 crystallites smaller than 3.5 nm which do not reduce easily to Co(0) state. The crystallite size of Co3O4 plays a role in its reduction to Co(0). TPR results showed that the reduction temperature shifts to higher temperature due to metal-support interaction. The variation in the activity of the catalysts depends on the support which in turn affects the crystallite size, dispersion, reducibility and activity of Co species in Fischer-Tropsch Synthesis (FTS). In this study, Co/Al2O3 showed higher CO conversion than the other catalysts. However, the C5+ production was in order Co/SiO2 (78.1%) > Co/Al2O3 (70.0%) > Co/R_TiO2 (61%) > Co/A_TiO2 (57.5%).

  5. Attrition resistant Fischer-Tropsch catalyst and support

    DOEpatents

    Singleton, Alan H.; Oukaci, Rachid; Goodwin, James G.

    2004-05-25

    A catalyst support having improved attrition resistance and a catalyst produced therefrom. The catalyst support is produced by a method comprising the step of treating calcined .gamma.-alumina having no catalytic material added thereto with an acidic aqueous solution having an acidity level effective for increasing the attrition resistance of the calcined .gamma.-alumina.

  6. Incorporation of Reaction Kinetics into a Multiphase, Hydrodynamic Model of a Fischer Tropsch Slurry Bubble Column Reactor

    SciTech Connect

    Donna Guillen, PhD; Anastasia Gribik; Daniel Ginosar, PhD; Steven P. Antal, PhD

    2008-11-01

    This paper describes the development of a computational multiphase fluid dynamics (CMFD) model of the Fischer Tropsch (FT) process in a Slurry Bubble Column Reactor (SBCR). The CMFD model is fundamentally based which allows it to be applied to different industrial processes and reactor geometries. The NPHASE CMFD solver [1] is used as the robust computational platform. Results from the CMFD model include gas distribution, species concentration profiles, and local temperatures within the SBCR. This type of model can provide valuable information for process design, operations and troubleshooting of FT plants. An ensemble-averaged, turbulent, multi-fluid solution algorithm for the multiphase, reacting flow with heat transfer was employed. Mechanistic models applicable to churn turbulent flow have been developed to provide a fundamentally based closure set for the equations. In this four-field model formulation, two of the fields are used to track the gas phase (i.e., small spherical and large slug/cap bubbles), and the other two fields are used for the liquid and catalyst particles. Reaction kinetics for a cobalt catalyst is based upon values reported in the published literature. An initial, reaction kinetics model has been developed and exercised to demonstrate viability of the overall solution scheme. The model will continue to be developed with improved physics added in stages.

  7. Effects of vanadium and zinc promotion on the olefin selectivity of iron Fischer-Tropsch catalysts

    SciTech Connect

    Saglam, M.

    1989-02-01

    The aim in most of the studies on Fischer-Tropsch synthesis has been the selective production of olefins, which are the raw materials of petrochemical industry. In this study, the effects of V and Zn addition, separately or together in the form of their oxides, to Fe catalysts obtained through precipitation on the olefin selectivity of the catalysts have been investigated. The experiments have been done in a fixed-bed reactor at different temperatures and pressures with various ratios of H/sub 2//CO. The addition of V separately (catalyst 2) or together with Zn (catalyst 1) has greatly increased the olefin selectivity of Fe catalyst. So the amount of olefin in hydrocarbon fractions has reached over 80%. Besides, the ..cap alpha..-olefin parts in olefin fractions have gone over 90%. But the addition of Zn separately has been less effective on the olefin selectivity of the catalyst.

  8. Attrition Resistant Fischer-Tropsch Catalysts Based on FCC Supports

    SciTech Connect

    Adeyiga, Adeyinka

    2010-02-05

    Commercial spent fluid catalytic cracking (FCC) catalysts provided by Engelhard and Albemarle were used as supports for Fe-based catalysts with the goal of improving the attrition resistance of typical F-T catalysts. Catalysts with the Ruhrchemie composition (100 Fe/5 Cu/4.2 K/25 spent FCC on mass basis) were prepared by wet impregnation. XRD and XANES analysis showed the presence of Fe{sub 2}O{sub 3} in calcined catalysts. FeC{sub x} and Fe{sub 3}O{sub 4} were present in the activated catalysts. The metal composition of the catalysts was analyzed by ICP-MS. F-T activity of the catalysts activated in situ in CO at the same conditions as used prior to the attrition tests was measured using a fixed bed reactor at T = 573 K, P = 1.38 MPa and H{sub 2}:CO ratio of 0.67. Cu and K promoted Fe supported over Engelhard provided spent FCC catalyst shows relatively good attrition resistance (8.2 wt% fines lost), high CO conversion (81%) and C{sub 5}+ hydrocarbons selectivity (18.3%).

  9. Iron Aerogel and Xerogel Catalysts for Fischer-Tropsch Synthesis of Diesel Fuel

    SciTech Connect

    Bali, S.; Huggins, F; Huffman, G; Ernst, R; Pugmire, R; Eyring, E

    2009-01-01

    Iron aerogels, potassium-doped iron aerogels, and potassium-doped iron xerogels have been synthesized and characterized and their catalytic activity in the Fischer-Tropsch (F-T) reaction has been studied. Iron aerogels and xerogels were synthesized by polycondensation of an ethanolic solution of iron(III) chloride hexahydrate with propylene oxide which acts as a proton scavenger for the initiation of hydrolysis and polycondensation. Potassium was incorporated in the iron aerogel and iron xerogel by adding aqueous K{sub 2}CO{sub 3} to the ethanolic solutions of the Fe(III) precursor prior to addition of propylene oxide. Fischer-Tropsch activities of the catalysts were tested in a fixed bed reactor at a pressure of 100 psi with a H{sub 2}:CO ratio of 2:1. Iron aerogels were found to be active for F-T synthesis, and their F-T activities increased on addition of a K containing promoter. Moessbauer spectroscopic data are consistent with an open, nonrigid iron(III) aerogel structure progressing to an iron carbide/metallic iron catalyst via agglomeration as the F-T synthesis proceeds in the course of a 35 h fixed bed reaction test.

  10. Mechanism of promotion of iron Fischer-Tropsch catalysts: Final report

    SciTech Connect

    Tau, L.M.; Dabbagh, H.; Chawla, B.; Davis, B.H.

    1987-12-31

    The kinetic isotope method (KIM) has been utilized in a study designed to determine the way in which promoters for iron catalysts impact the variety of primary and secondary reactions in the Fischer-Tropsch synthesis (FTS). The KIM involves the addition of known or suspected intermediates to the synthesis gas feed. In order to follow the conversion of the added compound, and the products formed as a result of the addition, the added compound is labeled with a radioactive isotope of carbon. An analysis of the Fischer-Tropsch synthesis products readily permits one to identify those compounds that are derived from the added compound. Using this technique, results were obtained with unpromoted iron, iron promoted by Al/sub 2/O/sub 3/, ThO/sub 2/, ZrO/sub 2/, and SiO/sub 2/, and alkali promoted iron catalysts. A combination of gas chromatographic, dry column chromatographic and liquid chromatographic techniques allowed us to determine the /sup 14/C present in compounds over the C/sub 1/--C/sub 22/ range in the alkane and alkene fractions. A continuous stirred tank reactor (CSTR) was used for most of the experimental studies. 108 refs., 100 figs., 6 tabs.

  11. Separation of Fischer-Tropsch Wax from Catalyst by Supercritical Extraction

    SciTech Connect

    Joyce, P.C.; Thies, M.C.

    1997-01-31

    The proposed process of using supercritical fluid extraction in conjunction with the Fischer-Tropsch slurry bubble column reactor has been examined using the ASPEN Plus simulator by the research group at North Carolina State University. Qualitative results have been obtained for varying the following process parameters: solvent-to-wax ratio, solvent type (pentane or hexane), extraction temperature and pressure, and recovery unit temperature and pressure. The region of retrograde behavior was determined for pentane and hexane. Initial results show hexane to be the superior solvent; compared to pentane, hexane requires lower quantities of solvent makeup (the amount of solvent which needs to be added to account for solvent that cannot be recycled), and also results in a lower average molecular weight of slurry in the reactor. Studies indicate that increasing the extraction temperature, extraction pressure, recovery temperature, or solvent to wax ratio decreases the amount solvent makeup required. Decreasing the recovery pressure was found to decrease the makeup flowrate.

  12. Fischer-Tropsch Synthesis on Ceramic Monolith-Structured Catalysts

    SciTech Connect

    Wang, Yong; Liu, Wei

    2009-04-19

    This paper reports recent research results about impact of different catalyst bed configurations on FT reaction product distribution. A CoRe/γ-alumina catalyst is prepared in bulk particle form and tested in the packed bed reactor at a size of 60 to 100 mesh. The same catalyst is ball milled and coated on a ceramic monolith support structure of channel size about 1mm. The monolith catalyst module is tested in two different ways, as a whole piece and as well-defined channels. Steady-state reaction conversion is measured at various temperatures under constant H2/CO feed ratio of 2 and reactor pressure of 25 bar. Detailed product analysis is performed. Significant formation of wax is evident with the packed particle bed and with the monolith catalyst that is improperly packed. By contrast, the wax formation is not detected in the liquid product by confining the reactions inside the monolith channel. This study presents an important finding about the structured catalyst/reactor system that the product distribution highly depends on the way how the structured reactor is set up. Even if the same catalyst and same reaction conditions (T, P, H2/oil ratio) are used, hydrodynamics (or flow conditions) inside a structured channel can have a significant impact on the product distribution.

  13. ε-Iron carbide as a low-temperature Fischer-Tropsch synthesis catalyst.

    PubMed

    Xu, Ke; Sun, Bo; Lin, Jun; Wen, Wen; Pei, Yan; Yan, Shirun; Qiao, Minghua; Zhang, Xiaoxin; Zong, Baoning

    2014-12-12

    ε-Iron carbide has been predicted to be promising for low-temperature Fischer-Tropsch synthesis (LTFTS) targeting liquid fuel production. However, directional carbidation of metallic iron to ε-iron carbide is challenging due to kinetic hindrance. Here we show how rapidly quenched skeletal iron featuring nanocrystalline dimensions, low coordination number and an expanded lattice may solve this problem. We find that the carbidation of rapidly quenched skeletal iron occurs readily in situ during LTFTS at 423-473 K, giving an ε-iron carbide-dominant catalyst that exhibits superior activity to literature iron and cobalt catalysts, and comparable to more expensive noble ruthenium catalyst, coupled with high selectivity to liquid fuels and robustness without the aid of electronic or structural promoters. This finding may permit the development of an advanced energy-efficient and clean fuel-oriented FTS process on the basis of a cost-effective iron catalyst.

  14. Metal organic framework-mediated synthesis of highly active and stable Fischer-Tropsch catalysts.

    PubMed

    Santos, Vera P; Wezendonk, Tim A; Jaén, Juan José Delgado; Dugulan, A Iulian; Nasalevich, Maxim A; Islam, Husn-Ubayda; Chojecki, Adam; Sartipi, Sina; Sun, Xiaohui; Hakeem, Abrar A; Koeken, Ard C J; Ruitenbeek, Matthijs; Davidian, Thomas; Meima, Garry R; Sankar, Gopinathan; Kapteijn, Freek; Makkee, Michiel; Gascon, Jorge

    2015-03-05

    Depletion of crude oil resources and environmental concerns have driven a worldwide research on alternative processes for the production of commodity chemicals. Fischer-Tropsch synthesis is a process for flexible production of key chemicals from synthesis gas originating from non-petroleum-based sources. Although the use of iron-based catalysts would be preferred over the widely used cobalt, manufacturing methods that prevent their fast deactivation because of sintering, carbon deposition and phase changes have proven challenging. Here we present a strategy to produce highly dispersed iron carbides embedded in a matrix of porous carbon. Very high iron loadings (>40 wt %) are achieved while maintaining an optimal dispersion of the active iron carbide phase when a metal organic framework is used as catalyst precursor. The unique iron spatial confinement and the absence of large iron particles in the obtained solids minimize catalyst deactivation, resulting in high active and stable operation.

  15. Metal organic framework-mediated synthesis of highly active and stable Fischer-Tropsch catalysts

    NASA Astrophysics Data System (ADS)

    Santos, Vera P.; Wezendonk, Tim A.; Jaén, Juan José Delgado; Dugulan, A. Iulian; Nasalevich, Maxim A.; Islam, Husn-Ubayda; Chojecki, Adam; Sartipi, Sina; Sun, Xiaohui; Hakeem, Abrar A.; Koeken, Ard C. J.; Ruitenbeek, Matthijs; Davidian, Thomas; Meima, Garry R.; Sankar, Gopinathan; Kapteijn, Freek; Makkee, Michiel; Gascon, Jorge

    2015-03-01

    Depletion of crude oil resources and environmental concerns have driven a worldwide research on alternative processes for the production of commodity chemicals. Fischer-Tropsch synthesis is a process for flexible production of key chemicals from synthesis gas originating from non-petroleum-based sources. Although the use of iron-based catalysts would be preferred over the widely used cobalt, manufacturing methods that prevent their fast deactivation because of sintering, carbon deposition and phase changes have proven challenging. Here we present a strategy to produce highly dispersed iron carbides embedded in a matrix of porous carbon. Very high iron loadings (>40 wt %) are achieved while maintaining an optimal dispersion of the active iron carbide phase when a metal organic framework is used as catalyst precursor. The unique iron spatial confinement and the absence of large iron particles in the obtained solids minimize catalyst deactivation, resulting in high active and stable operation.

  16. DEVELOPMENT OF A COMPUTATIONAL MULTIPHASE FLOW MODEL FOR FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR

    SciTech Connect

    Donna Post Guillen; Tami Grimmett; Anastasia M. Gribik; Steven P. Antal

    2011-12-01

    The Hybrid Energy Systems Testing (HYTEST) Laboratory at the Idaho National Laboratory was established to develop and test hybrid energy systems with the principal objective of reducing dependence on imported fossil fuels. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions are performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. These SBCRs operate in the churn-turbulent flow regime, which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer. Our team is developing a research tool to aid in understanding the physicochemical processes occurring in the SBCR. A robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) consisting of thirteen species, which are CO reactant, H2 reactant, hydrocarbon product, and H2O product in small bubbles, large bubbles, and the bulk fluid plus catalyst is outlined. Mechanistic submodels for interfacial momentum transfer in the churn-turbulent flow regime are incorporated, along with bubble breakup/coalescence and two-phase turbulence submodels. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield. The model includes heat generation produced by the exothermic chemical reaction, as well as heat removal from a constant temperature heat exchanger. A property method approach is employed to incorporate vapor-liquid equilibrium (VLE) in a robust manner. Physical and thermodynamic properties as functions of changes in both pressure and temperature are obtained from VLE calculations performed external to the CMFD solver. The novelty of this approach is in its simplicity, as well as its

  17. Preparation of Fischer-Tropsch catalysts from cobalt/iron hydrotalcites

    SciTech Connect

    Howard, B.H.; Boff, J.J.; Zarochak, M.F.

    1995-12-31

    Compounds with the (hydrotalcites) have properties that make them attractive as precursors for Fischer-Tropsch catalysts. A series of single-phase hydrotalcites with cobalt/iron atom ratios ranging from 75/25 to 25/75 has been synthesized. Mixed cobalt/iron oxides have been prepared from these hydrotalcites by controlled thermal decomposition. Thermal decomposition at temperatures below 600 {degrees}C typically produced a single-phase mixed metal oxide with a spinel structure. The BET surface areas of the spinal samples have been found to be as high as about 150 m{sup 2}/g. Appropriate reducing pretreatments have been developed for several of these spinels and their activity, selectivity, and activity and selectivity maintenance have been examined at 13 MPa in a fixed-bed microreactor.

  18. Isotopic tracer studies of Fischer-Tropsch Synthesis over Ru/TiO sub 2 catalysts

    SciTech Connect

    Krishna, K.R.

    1992-01-01

    Fischer-Tropsch synthesis is a process in which CO and H{sub 2} react to give predominantly liquid hydrocarbons. The reaction can be considered a special type of polymerization in which the monomer is produced in situ, and chain growth occurs by a sequence of independently repeated additions of the monomer to the growing chain. A investigation has been conducted to study the CO hydrogenation reaction in order to better understand catalyst deactivation and the elementary surface processes involved in chain growth. Isotopic tracers are used in conjunction with transient-response techniques in this study of Fischer-Tropsch synthesis over Ru/TiO{sub 2} catalysts. Experiments are conducted at a total pressure of 1 atmosphere, reaction temperatures of 453--498 K and D{sub 2}/CO (or H{sub 2}/CO) ratios of 2--5. Synthesis products are analyzed by gas chromatography or isotope-ratio gas chromatography-mass spectrometry. Rate constants for chain initiation, propagation and termination are evaluated under steady-state reaction conditions by using transients in isotopic composition. The activation energy for chain termination is much higher than that for propagation, accounting for the observed decrease in the chain growth parameter are also estimated. Coverages by reaction intermediates are also estimated. When small amounts of {sup 12}C-labelled ethylene are added to {sup 13}CO/H{sub 2} synthesis gas, ethylene acts as the sole chain initiator. Ethylene-derived carbon also accounts for 45% of the C{sub 1} monomer pool. 102 refs., 29 figs., 11 tabs.

  19. Techno-economic assessment of the Mobil Two-Stage Slurry Fischer-Tropsch/ZSM-5 process

    SciTech Connect

    El Sawy, A.; Gray, D.; Neuworth, M.; Tomlinson, G.

    1984-11-01

    A techno-economic assessment of the Mobil Two-Stage Slurry Fischer-Tropsch reactor system was carried out. Mobil bench-scale data were evaluated and scaled to a commercial plant design that produced specification high-octane gasoline and high-cetane diesel fuel. Comparisons were made with three reference plants - a SASOL (US) plant using dry ash Lurgi gasifiers and Synthol synthesis units, a modified SASOL plant with a British Gas Corporation slagging Lurgi gasifier (BGC/Synthol) and a BGC/slurry-phase process based on scaled data from the Koelbel Rheinpreussen-Koppers plant. A conceptual commercial version of the Mobil two-stage process shows a higher process efficiency than a SASOL (US) and a BGC/Synthol plant. The Mobil plant gave lower gasoline costs than obtained from the SASOL (US) and BGC/Synthol versions. Comparison with published data from a slurry-phase Fischer-Tropsch (Koelbel) unit indicated that product costs from the Mobil process were within 6% of the Koelbel values. A high-wax version of the Mobil process combined with wax hydrocracking could produce gasoline and diesel fuel at comparable cost to the lowest values achieved from prior published slurry-phase results. 27 references, 18 figures, 49 tables.

  20. DEVELOPMENT OF A COMPUTATIONAL MULTIPHASE FLOW MODEL FOR FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR

    SciTech Connect

    Donna Post Guillen; Tami Grimmett; Anastasia M. Gribik; Steven P. Antal

    2010-09-01

    The Hybrid Energy Systems Testing (HYTEST) Laboratory is being established at the Idaho National Laboratory to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions will be performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. SBCRs are cylindrical vessels in which gaseous reactants (for example, synthesis gas or syngas) is sparged into a slurry of liquid reaction products and finely dispersed catalyst particles. The catalyst particles are suspended in the slurry by the rising gas bubbles and serve to promote the chemical reaction that converts syngas to a spectrum of longer chain hydrocarbon products, which can be upgraded to gasoline, diesel or jet fuel. These SBCRs operate in the churn-turbulent flow regime which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer, that effect reactor performance. The purpose of this work is to develop a computational multiphase fluid dynamic (CMFD) model to aid in understanding the physico-chemical processes occurring in the SBCR. Our team is developing a robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) that includes twelve species: (1) CO reactant, (2) H2 reactant, (3) hydrocarbon product, and (4) H2O product in small bubbles, large bubbles, and the bulk fluid. Properties of the hydrocarbon product were specified by vapor liquid equilibrium calculations. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is determined based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield [1]. The

  1. Fischer-Tropsch Cobalt Catalyst Activation and Handling Through Wax Enclosure Methods

    NASA Technical Reports Server (NTRS)

    Klettlinger, Jennifer L. S.; Yen, Chia H.; Nakley, Leah M.; Surgenor, Angela D.

    2016-01-01

    Fischer-Tropsch (F-T) synthesis is considered a gas to liquid process which converts syn-gas, a gaseous mixture of hydrogen and carbon monoxide, into liquids of various hydrocarbon chain length and product distributions. Cobalt based catalysts are used in F-T synthesis and are the focus of this paper. One key concern with handling cobalt based catalysts is that the active form of catalyst is in a reduced state, metallic cobalt, which oxidizes readily in air. In laboratory experiments, the precursor cobalt oxide catalyst is activated in a fixed bed at 350 ?C then transferred into a continuous stirred tank reactor (CSTR) with inert gas. NASA has developed a process which involves the enclosure of active cobalt catalyst in a wax mold to prevent oxidation during storage and handling. This improved method allows for precise catalyst loading and delivery into a CSTR. Preliminary results indicate similar activity levels in the F-T reaction in comparison to the direct injection method. The work in this paper was supported by the NASA Fundamental Aeronautics Subsonics Fixed Wing Project.

  2. Improved Fischer-Tropsch catalysts for indirect coal liquefaction. Final report

    SciTech Connect

    Wilson, R.B. Jr.; Tong, G.T.; Chan, Y.W.; Huang, H.W.; McCarty, J.G.

    1989-02-01

    The Fischer-Tropsch synthesis (FTS)reaction is the established technology for the production of liquid fuels from coal by an indirect route using coal-derived syngas (CO + H{sub 2}). Modern FTS catalysts are potassium- and copper-promoted iron preparations. These catalysts exhibit moderate activity with carbon monoxide-rich feedstocks such as the syngas produced by advanced coal gasification processes. However, the relatively large yields of by-product methane and high-molecular-weight hydrocarbon waxes detract from the production of desired liquid products in the C{sub 5}-C{sub 16} range needed for motor and aviation fuel. The goal of this program is to decrease undesirable portions of the FTS hydrocarbon yield by altering the Schultz-Flory polymerization product distribution through design and formulation of improved catalysts. Two approaches were taken: (1) reducing the yield of high-molecular-weight hydrocarbon waxes by using highly dispersed catalysts produced from surface-confined multiatomic clusters on acid supports and (2) suppressing methane production by uniformly pretreating active, selective conventional FTS catalysts with submonolayer levels of sulfur.

  3. Nanocrystalline Iron-Ore-Based Catalysts for Fischer-Tropsch Synthesis.

    PubMed

    Yong, Seok; Park, Ji Chan; Lee, Ho-Tae; Yang, Jung-Il; Hong, SungJun; Jung, Heon; Chun, Dong Hyun

    2016-02-01

    Nanocrystalline iron ore particles were fabricated by a wet-milling process using an Ultra Apex Mill, after which they were used as raw materials of iron-based catalysts for low-temperature Fischer-Tropsch synthesis (FTS) below 280 degrees C, which usually requires catalysts with a high surface area, a large pore volume, and a small crystallite size. The wet-milling process using the Ultra Apex Mill effectively destroyed the initial crystallite structure of the natural iron ores of several tens to hundreds of nanometers in size, resulting in the generation of nanocrystalline iron ore particles with a high surface area and a large pore volume. The iron-ore-based catalysts prepared from the nanocrystalline iron ore particles effectively catalyzed the low-temperature FTS, displaying a high CO conversion (about 90%) and good C5+ hydrocarbon productivity (about 0.22 g/g(cat)(-h)). This demonstrates the feasibility of using the iron-ore-based catalysts as inexpensive and disposable catalysts for the low-temperature FTS.

  4. Correlation between Fischer-Tropsch catalytic activity and composition of catalysts

    PubMed Central

    2011-01-01

    This paper presents the synthesis and characterization of monometallic and bimetallic cobalt and iron nanoparticles supported on alumina. The catalysts were prepared by a wet impregnation method. Samples were characterized using temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), CO-chemisorption, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM-EDX) and N2-adsorption analysis. Fischer-Tropsch synthesis (FTS) was carried out in a fixed-bed microreactor at 543 K and 1 atm, with H2/CO = 2 v/v and space velocity, SV = 12L/g.h. The physicochemical properties and the FTS activity of the bimetallic catalysts were analyzed and compared with those of monometallic cobalt and iron catalysts at similar operating conditions. H2-TPR analysis of cobalt catalyst indicated three temperature regions at 506°C (low), 650°C (medium) and 731°C (high). The incorporation of iron up to 30% into cobalt catalysts increased the reduction, CO chemisorption and number of cobalt active sites of the catalyst while an opposite trend was observed for the iron-riched bimetallic catalysts. The CO conversion was 6.3% and 4.6%, over the monometallic cobalt and iron catalysts, respectively. Bimetallic catalysts enhanced the CO conversion. Amongst the catalysts studied, bimetallic catalyst with the composition of 70Co30Fe showed the highest CO conversion (8.1%) while exhibiting the same product selectivity as that of monometallic Co catalyst. Monometallic iron catalyst showed the lowest selectivity for C5+ hydrocarbons (1.6%). PMID:22047220

  5. Metal (Fe, Co, Ni) supported on different aluminas as Fischer-Tropsch catalyst

    NASA Astrophysics Data System (ADS)

    Dahlan, Marsih, I. Nyoman; Makertihartha, I. G. B. N.; Praserthdam, Piyasan; Panpranot, Joongjai; Ismunandar

    2015-09-01

    This research aimed to compare the physico-chemical properties of the same metal M (M = iron, cobalt, nickel) supported on aluminas with different morphology and pore size as Fischer-Tropsch catalyst. The aluminas applied as support were alumina synthesized through hydrothermal process, alumina formed by pretreatment of catapal and commercial alumina which named as Ahy, Aca, and Aco respectively. Ahy has uniform morphology of nanotubes while Aca and Aco showed non-uniform morphology of particle lumps. The particle lumps of Aca were larger than those of Aco. Ahy, Aca, and Aco respectively has average pore diameter of 2.75, 2.86 and 2.9 nm. Metals were deposited on the supports by incipient-wetness impregnation method. The catalysts were characterized by XRD, H2-TPR, and H2 chemisorption. Catalyst acitivity test for Fischer-Tropsch reaction was carried out in a micro reactor at 200 °C and 1 atm, and molar ratio of H2/CO = 2:1. The metal oxide particle size increased in the order M/Aco < M/Aca < M/Ahy. The catalysts reducibility also increased according to the order M/Aco < M/Aca < M/Ahy suggesting that the larger metal oxide particles are more reducible. The number of active site was not proportional to the reducibility because during the reduction, larger metal oxide particles were converted into larger metal particles. On the other hand, the number of active sites was inversely proportional to the particle sizes. The number of active site increased in the order M/Ahy < M/Aco < M/Aca. The catalytic activity also increased in the following order M/Ahy < M/Aco < M/Aca. The activity per active site increased according to the order M/Aca < M/Aco < M/Ahy meaning that for M/Ahy, a little increase in active site will lead to a significance increase in catalytic activity. It showed that Ahy has potential for the better support.

  6. Metal (Fe, Co, Ni) supported on different aluminas as Fischer-Tropsch catalyst

    SciTech Connect

    Dahlan; Marsih, I. Nyoman Ismunandar; Makertihartha, I. G. B. N.; Praserthdam, Piyasan; Panpranot, Joongjai

    2015-09-30

    This research aimed to compare the physico-chemical properties of the same metal M (M = iron, cobalt, nickel) supported on aluminas with different morphology and pore size as Fischer-Tropsch catalyst. The aluminas applied as support were alumina synthesized through hydrothermal process, alumina formed by pretreatment of catapal and commercial alumina which named as Ahy, Aca, and Aco respectively. Ahy has uniform morphology of nanotubes while Aca and Aco showed non-uniform morphology of particle lumps. The particle lumps of Aca were larger than those of Aco. Ahy, Aca, and Aco respectively has average pore diameter of 2.75, 2.86 and 2.9 nm. Metals were deposited on the supports by incipient-wetness impregnation method. The catalysts were characterized by XRD, H{sub 2}-TPR, and H{sub 2} chemisorption. Catalyst acitivity test for Fischer-Tropsch reaction was carried out in a micro reactor at 200 °C and 1 atm, and molar ratio of H{sub 2}/CO = 2:1. The metal oxide particle size increased in the order M/Aco < M/Aca < M/Ahy. The catalysts reducibility also increased according to the order M/Aco < M/Aca < M/Ahy suggesting that the larger metal oxide particles are more reducible. The number of active site was not proportional to the reducibility because during the reduction, larger metal oxide particles were converted into larger metal particles. On the other hand, the number of active sites was inversely proportional to the particle sizes. The number of active site increased in the order M/Ahy < M/Aco < M/Aca. The catalytic activity also increased in the following order M/Ahy < M/Aco < M/Aca. The activity per active site increased according to the order M/Aca < M/Aco < M/Ahy meaning that for M/Ahy, a little increase in active site will lead to a significance increase in catalytic activity. It showed that Ahy has potential for the better support.

  7. Carbon induced selective regulation of cobalt-based Fischer-Tropsch catalysts by ethylene treatment.

    PubMed

    Zhai, Peng; Chen, Pei-Pei; Xie, Jinglin; Liu, Jin-Xun; Zhao, Huabo; Lin, Lili; Zhao, Bo; Su, Hai-Yan; Zhu, Qingjun; Li, Wei-Xue; Ma, Ding

    2017-02-10

    Various carbonaceous species were controllably deposited on Co/Al2O3 catalysts using ethylene as carbon source during the activation process for Fischer-Tropsch synthesis (FTS). Atomic, polymeric and graphitic carbon were distinguished by Raman spectroscopy, thermoanalysis and temperature programmed hydrogenation. Significant changes occurred in both the catalytic activity and selectivity toward hydrocarbon products after ethylene treatment. The activity decreased along with an increase in CH4 selectivity, at the expense of a remarkable decrease of heavy hydrocarbon production, resulting in enhanced selectivity for the gasoline fraction. In situ XPS experiments show the possible electron transfer from cobalt to carbon and the blockage of metallic cobalt sites, which is responsible for the deactivation of the catalyst. DFT calculations reveal that the activation barrier (Ea) of methane formation decreases by 0.61 eV on the carbon-absorbed Co(111) surface, whereas the Ea of the CH + CH coupling reaction changes unnoticeably. Hydrogenation of CHx to methane becomes the preferable route among the elementary reactions on the Co(111) surface, leading to dramatic changes in the product distribution. Detailed coke-induced deactivation mechanisms of Co-based catalysts during FTS are discussed.

  8. Silylated Co/SBA-15 catalysts for Fischer-Tropsch synthesis

    SciTech Connect

    Jia Lihong; Jia Litao; Li Debao; Hou Bo; Wang Jungang; Sun Yuhan

    2011-03-15

    A series of silylated Co/SBA-15 catalysts were prepared via the reaction of surface Si-OH of SBA-15 with hexamethyldisilazane (HMDS) under anhydrous, vapor-phase conditions, and then characterized by FT-IR, N{sub 2} physisorption, TG, XRD, and TPR-MS. The results showed that organic modification led to a silylated SBA-15 surface composed of stable hydrophobic Si-(CH{sub 3}){sub 3} species even after calcinations and H{sub 2} reduction at 673 K. Furthermore, the hydrophobic surface strongly influenced both metal dispersion and reducibility. Compared with non-silylated Co/SBA, Co/S-SBA (impregnation after silylation) showed a high activity, due to the better cobalt reducibility on the hydrophobic support. However, S-Co/SBA (silylation after impregnation) had the lowest FT activity among all the catalysts, due to the lower cobalt reducibility along with the steric hindrance of grafted -Si(CH{sub 3}){sub 3} for the re-adsorption of {alpha}-olefins. -- Graphical abstract: The silylation of an SBA-15 before cobalt impregnation enhanced the reducibility of cobalt oxides on an SBA-15-supported cobalt catalyst and consequently increased the catalytic activity for Fischer-Tropsch synthesis. Display Omitted

  9. SEPARATION OF FISCHER-TROPSCH WAX FROM CATALYST BY SUPERCRITICAL EXTRACTION

    SciTech Connect

    Patrick C. Joyce; Mark C. Thies

    1999-03-31

    The objective of this research project was to evaluate the potential of supercritical fluid (SCF) extraction for the recovery and fractionation of the wax product from the slurry bubble column (SBC) reactor of the Fischer-Tropsch (F-T) process. The wax, comprised mostly of branched and linear alkanes with a broad molecular weight distribution up to C{sub 100}, is to be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300 C. Aspen Plus{trademark} was used to perform process simulation studies on the proposed extraction process, with Redlich-Kwong-Soave (RKS) being used for the thermodynamic property model. In summary, we have made comprehensive VLE measurements for short alkane + long alkane systems over a wide range of pressures and temperatures, dramatically increasing the amount of high-quality data available for these simple, yet highly relevant systems. In addition, our work has demonstrated that, surprisingly, no current thermodynamic model can adequately predict VLE behavior for these systems. Thus, process simulations (such as those for our proposed SCF extraction process) that incorporate these systems can currently only give results that are qualitative at best. Although significant progress has been made in the past decade, more experimental and theoretical work remain to be done before the phase equilibria of asymmetric alkane mixtures can be predicted with confidence.

  10. Study of structural and catalytic properties of Ni catalysts prepared from inorganic complex precursor for Fischer-Tropsch synthesis

    NASA Astrophysics Data System (ADS)

    Saheli, Sania; Rezvani, Ali Reza; Malekzadeh, Azim

    2017-09-01

    The silica- and alumina- supported Ni catalysts synthesized by thermal decomposition of inorganic precursors were evaluated for Fischer-Tropsch synthesis (FTS); the structural properties and performance of the catalysts were compared to those of samples constructed via impregnation method. The results revealed that the synthesized catalysts have higher catalytic activity comparison to those prepared via the conventional impregnation method. The effect of the preparation method on the structural properties shows that synthesizing the catalyst through inorganic precursor route is more appropriate. Characterization of catalysts is carried out using inductively coupled plasma (ICP), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and BET specific surface area.

  11. In situ observation of self-assembled hydrocarbon Fischer-Tropsch products on a cobalt catalyst

    NASA Astrophysics Data System (ADS)

    Navarro, Violeta; van Spronsen, Matthijs A.; Frenken, Joost W. M.

    2016-10-01

    Fischer-Tropsch synthesis is a heterogeneous catalytic reaction that creates approximately 2% of the world's fuel. It involves the synthesis of linear hydrocarbon molecules from a gaseous mixture of carbon monoxide and hydrogen at high pressures (from a few to tens of bars) and high temperatures (200-350 °C). To gain further insight into the fundamental mechanisms of this industrial process, we have used a purpose-built scanning tunnelling microscope to monitor a cobalt model catalyst under reaction conditions. We show that, after 30 minutes of reaction, the terraces of the cobalt catalyst are covered by parallel arrays of stripes. We propose that the stripes are formed by the self-assembly of linear hydrocarbon product molecules. Surprisingly, the width of the stripes corresponds to molecules that are 14 or 15 carbon atoms long. We introduce a simple model that explains the accumulation of such long molecules by describing their monomer-by-monomer synthesis and explicitly accounting for their thermal desorption.

  12. Exploring iron-based multifunctional catalysts for Fischer-Tropsch synthesis: a review.

    PubMed

    Abelló, Sònia; Montané, Daniel

    2011-11-18

    The continuous increase in oil prices together with an increase in carbon dioxide concentration in the atmosphere has prompted an increased interest in the production of liquid fuels from non-petroleum sources to ensure the continuation of our worldwide demands while maximizing CO(2) utilization. In this sense, the Fischer-Tropsch (FT) technology provides a feasible option to render high value-added hydrocarbons. Alternative sources, such as biomass or coal, offer a real possibility to realize these purposes by making use of H(2)-deficient or CO(2)-rich syngas feeds. The management of such feeds ideally relies on the use of iron catalysts, which exhibit the unique ability to adjust the H(2)/CO molar ratio to an optimum value for hydrocarbon synthesis through the water-gas-shift reaction. Taking advantage of the emerging attention to hybrid FT-synthesis catalysts based on cobalt and their associated benefits, an overview of the current state of literature in the field of iron-based multifunctional catalysts is presented. Of particular interest is the use of zeolites in combination with a FT catalyst in a one-stage operation, herein named multifunctional, which offer key opportunities in the modification of desired product distributions and selectivity, to eventually overcome the quality limitations of the fuels prepared under intrinsic FT conditions. This review focuses on promising research activities addressing the conversion of syngas to liquid fuels mediated by iron-based multifunctional materials, highlights their preparation and properties, and discusses their implication and challenges in the area of carbon utilization through H(2)/CO(+CO(2)) mixtures.

  13. Activation studies with a precipitated iron catalyst for Fischer-Tropsch synthesis. I. Characterization studies

    SciTech Connect

    Bukur, D.B.; Okabe, Kiyomi; Rosynek, M.P.; Li, Chiuping

    1995-09-01

    A commercial promoted precipitated iron catalyst (100 Fe/5 Cu/4.2K/25 SiO{sub 2} by weight) was characterized after different pretreatment conditions and after Fischer-Tropsch (FT) synthesis in a fixed bed reactor. The BET-N{sub 2} surface area and pore volume of the catalyst decreased after pretreatments in hydrogen, carbon monoxide, or syngas. Isothermal and temperature-programmed reduction profiles indicate that iron reduction occurs in two steps: facile reduction of Fe{sub 2}O{sub 3} to Fe{sub 3}O{sub 4}, followed by slow reduction of Fe{sub 3}O{sub 4} to either metallic iron (H{sub 2} reduction) or an iron carbide (CO pretreatment). Calcined catalyst is in the form of poorly crystalline {alpha}-Fe{sub 2}O{sub 3}, which is partially converted to either magnetite (Fe{sub 3}O{sub 4}) or a mixture of {alpha}-Fe and Fe{sub 3}O{sub 4} after H{sub 2} reductions. During FT synthesis the {alpha}-Fe and a portion of iron oxides are carburized to a pseudohexagonal {epsilon}{prime}-Fe{sub 2.2}C. After CO or syngas pretreatments, the hematite is partly converted to a monoclinic {chi}-Fe{sub 5}C{sub 2} carbide. During FT synthesis this carbide is partially converted to magnetite. The degree of surface iron reduction, determined by X-ray photoelectron spectroscopy, was greater after the CO pretreatment at 300{degrees}C for 4 h than that obtained after the H{sub 2} reduction under the same conditions. However, in both cases a fraction of the surface iron remained in the form of unreduced Fe{sup 2+}/Fe{sup 3+} species. Also, the surface carbon deposits were formed during the CO pretreatment. 52 refs., 7 figs., 3 tabs.

  14. Hydrocarbon selectivity model for gas-solid Fischer-Tropsch synthesis on precipitated iron catalysts

    SciTech Connect

    Laan, G.P. van der; Beenackers, A.A.C.M.

    1999-04-01

    The kinetics of the gas-solid Fischer-Tropsch (FT) synthesis over a commercial Fe-Cu-K-SiO{sub 2} catalyst was studied in a continuous spinning basket reactor. Experimental conditions were varied as follows: reactor pressure of 0.8--3.2 MPa, H{sub 2}/CO feed ratio = 0.5--2.0, and a space velocity of 0.5--2.0 {times} 10{sup {minus}3} Nm{sup 3}/kg{sub cat} s at a constant temperature of 523 K. A new product distribution model for linear hydrocarbons is proposed. Deviations from conventional Anderson-Schulz-Flory distribution can be quantitatively described with an {alpha}-olefin readsorption product distribution model. The experimentally observed relatively high yield of methane, relatively low yield of ethene, and both the exponential decrease of the olefin-to-paraffin ratio and the change of the chain growth parameter with chain length can all be predicted from this new model. It combines a mechanistic model of olefin readsorption with kinetics of chain growth and termination on the same catalytic sites. The hydrocarbon formation is based on the surface carbide mechanism by CH{sub 2} insertion. The olefin readsorption rate depends on the chain length because of increasing physisorption strength on the catalyst surface and increasing solubility in FT wax with increasing chain length. Interfacial concentrations of reactive olefins near the gas-wax and wax-catalyst surface are used in the kinetic model. With optimization of three parameters per experimental product distribution, the olefin readsorption product distribution model proved to predict product selectivities accurately over the entire range of experimental conditions. The relative deviations are 10.1% and 9.1% for the selectivity to paraffins and olefins with n < 11, respectively.

  15. Mechanism and kinetics of Fischer-Tropsch synthesis over supported ruthenium catalysts

    SciTech Connect

    Kellner, C.S.

    1981-06-01

    A detailed study of the kinetics of the Fischer-Tropsch synthesis of hydrocarbons, methanol, and acetaldehyde, over alumina- and silica-supported ruthenium catalysts has been carried out over a broad range of reaction conditions. Based on these results and information taken from the literature, mechanisms for the formation of normal paraffins, ..cap alpha..-olefins, methanol, and acetaldehyde have been proposed. Rate data were obtained between 448 and 548K, 1 and 10 atm, and H/sub 2//CO ratios between 1 and 3, utilizing a micro flow reactor operated at very low conversions. In addition to the studies performed with H/sub 2//CO mixtures, a series of experiments were carried out utilizing D/sub 2//CO mixtures. These studies were used to help identify rate limited steps and steps that were at equilibrium. A complementary investigation, carried out by in situ infrared spectroscopy, was performed using a Fourier Transform spectrometer. The spectra obtained were used to identify the modes of CO adsorption, the CO coverage, and the relative reactivity of different forms of adsorbed CO. It was established that CO adsorbs on alumina-supported Ru in, at least, two forms: (i) Ru-CO and (ii) OC-Ru-CO. Only the first of these forms participates in CO hydrogenation. The coverage of this species is described by a simple Langmuir isotherm. A reaction mechanism is presented for interpreting the kinetics of hydrocarbon synthesis, the olefin to paraffin ratio for each product, and the probability of chain propagation. Rate expressions based on this mechanism are reasonably consistent with the experimental data. Acetaldehyde, obtained mainly over silica-supported Ru, appears to be formed by a mechanism related to that for hydroformulation of olefins. The effect of the dispersion of Ru/Al/sub 2/O/sub 3/ catalysts on their specific activity and selectivity was also investigated. The specific activity for all products decreased rapidly with increasing dispersions.

  16. Development of precipitated iron Fischer-Tropsch catalysts. Quarterly technical progress report for the period July 1, 1996--September 30, 1996

    SciTech Connect

    Bukur, D.B.

    1996-12-02

    Two slurry reactor tests were completed in continuation of our studies on the effect of pretreatment conditions on catalyst reactivity and selectivity. Exceptionally good performance was obtained in run SA-2186, using the new pretreatment developed at Texas A&M University. The work on catalyst characterization by temperature programmed and isothermal reduction on a variety of iron catalysts, with different amounts of promoters, has been continued. These studies are complementing our work on pretreatment effect research, and provide additional insights into the effect of pretreatment procedures on the reduction behavior of iron catalysts. The overall objectives are to: (1) demonstrate repeatability of performance and preparation procedure of two high activity, high alpha iron Fischer-Tropsch catalysts synthesized at Texas A&M University; (2) seek potential improvements in the catalysts performance through variation in process condition, pretreatment procedures and/or modifications in catalyst synthesis; (3) investigate performance of catalysts in a small bubble column slurry reactor; and (4) investigate feasibility of producing catalysts on a large scale in collaboration with a catalyst manufacturer.

  17. Phase transformation of iron-based catalysts for Fischer-Tropsch synthesis

    NASA Astrophysics Data System (ADS)

    Jin, Yaming

    Fischer-Tropsch (F-T) synthesis is used to convert syngas to liquid hydrocarbons using iron-based catalysts. However, the nature of the active phase and phase transformations during F-T synthesis are not well understood. In this work, the phase transformations of Fe catalysts both during F-T synthesis and controlled treatment conditions have been studied using cross-section transmission electron microscopy, x-ray diffraction and Mossbauer spectroscopy. Catalyst samples were obtained from F-T synthesis runs at medium pressure (1.48 MPa) with a H2:CO ratio of 0.7. Samples were analyzed without removal of the wax to preserve the catalyst microstructure intact and prevent oxidation due to air exposure. In all active Fe catalysts, a highly dispersed chi-carbide (Fe5C2) phase with an average particle size <10 nm was seen to be present along with larger sized particles of hexagonal Fe 7C3. On the other hand, the carbide phase whose XRD pattern resembles that obtained by the Barton and Gale was found to be associated with catalysts of low activity. All carbide particles are covered with amorphous carbonaceous layers as seen by electron energy loss spectroscopy (EELS). In a series of separate experiments, phase transformations that occur during catalyst activation at atmospheric pressure were studied. During direct CO carburization of iron oxide at 250°C, multiple nucleation sites lead to formation of smaller Fe carbide particles predominantly of the Barton-Gale carbide. However, starting from metallic Fe we obtain a chi-carbide phase without significant change in particle size. Treatment in syngas (H 2:CO = 0.7) results in less complete carburization and larger particle sizes for both the carbide and the magnetite phases. The presence of trace amounts of water vapor during reduction appears to cause formation of large faceted magnetite crystals, which are difficult to further transform to the active carbide phase. The silica support is effective at keeping the Fe phases

  18. Hydrodynamics of Fischer-Tropsch synthesis in slurry bubble column reactors: Final report

    SciTech Connect

    Bukur, D.B.; Daly, J.G.; Patel, S.A.; Raphael, M.L.; Tatterson, G.B.

    1987-06-01

    This report describes studies on hydrodynamics of bubble columns for Fischer-Tropsch synthesis. These studies were carried out in columns of 0.051 m and 0.229 m in diameter and 3 m tall to determine effects of operating conditions (temperature and gas flow rate), distributor type (sintered metal plate and single and multi-hole perforated plates) and liquid media (paraffin and reactor waxes) on gas hold-up and bubble size distribution. In experiments with the Fischer-Tropsch (F-T) derived paraffin wax (FT-300) for temperatures between 230 and 280/sup 0/C there is a range of gas velocities (transition region) where two values of gas hold-up (i.e., two flow regimes) are possible. Higher hold-ups were accompanied by the presence of foam (''foamy'' regime) whereas lower values were obtained in the absence of foam (''slug flow'' in the 0.051 m column, or ''churn-turbulent'' flow regime in the 0.229 m column). This type of behavior has been observed for the first time in a system with molten paraffin wax as the liquid medium. Several factors which have significant effect on foaming characteristics of this system were identified. Reactor waxes have much smaller tendency to foam and produce lower hold-ups due to the presence of larger bubbles. Finally, new correlations for prediction of the gas hold-up and the specific gas-liquid interfacial area were developed on the basis of results obtained in the present study. 49 refs., 99 figs., 19 tabs.

  19. Tailored fischer-tropsch synthesis product distribution

    DOEpatents

    Wang, Yong [Richland, WA; Cao, Chunshe [Kennewick, WA; Li, Xiaohong Shari [Richland, WA; Elliott, Douglas C [Richland, WA

    2012-06-19

    Novel methods of Fischer-Tropsch synthesis are described. It has been discovered that conducting the Fischer-Tropsch synthesis over a catalyst with a catalytically active surface layer of 35 microns or less results in a liquid hydrocarbon product with a high ratio of C.sub.5-C.sub.20:C.sub.20+. Descriptions of novel Fischer-Tropsch catalysts and reactors are also provided. Novel hydrocarbon compositions with a high ratio of C.sub.5-C.sub.20:C.sub.20+ are also described.

  20. The effect of 1-alkene addition on hydrocarbon product distribution in Fischer-Tropsch synthesis on a cobalt catalyst

    SciTech Connect

    Yates, I.C.; Satterfield, C.N.

    1991-07-01

    The cobalt-catalyzed reactions of C{sub 2}H{sub 4}, C{sub 3}H{sub 6}, or 1-C{sub 4}H{sub 8} added to synthesis gas in concentrations ranging from 0.5 to 1.2 mol. % of total feed were studied at 220{degrees}C, and 0.45 to 1.48 MPa. H{sub 2}/CO feed ratios were varied between 1.45 to 2.25 and H{sub 2} + CO conversions between 5 and 30% were observed. 1-Alkenes incorporate into growing chains on the catalyst surface, probably by initiating and/or terminating the chain growth process. Only ethene may propagate chain growth significantly. The propensity of the 1-alkenes to incorporate decreases with increasing carbon number of the 1-alkene and is affected by the extent of competitive reactions, notably hydrogenation to the alkene and isomerization to the 2-alkene. Incorporation is most evident in products above about C{sub 10}+. The double-{alpha} behavior exhibited by most Fischer-Tropsch catalysts can be interpreted as the sum of two growth processes, one a stepwise single-carbon growth process and the other a 1-alkene incorporation process. Many of the effects of process variables on the hydrocarbon selectivity of Fischer-Tropsch catalysts are consistent with this theory. 14 refs., 10 figs., 1 tab.

  1. Potassium effects on activated-carbon-supported iron catalysts for Fischer-Tropsch synthesis

    SciTech Connect

    Wenping Ma; Edwin L. Kugler; Dady B. Dadyburjor

    2007-08-15

    The effect of potassium on the activity, selectivity, and distribution of products (hydrocarbons and oxygenates) was studied over iron catalysts supported on activated carbon (AC) for Fischer-Tropsch synthesis (FTS). This is part of a wider study on the incremental effects of components (including the support) of a multicomponent (Fe-Cu-Mo-K/AC) FTS catalyst. The range of potassium loading used was 0-2 wt%. A fixed-bed reactor was used under the conditions of 260-300{sup o}C, 300 psig, and 3 Nl/g cat/h, using syngas with a H{sub 2}/CO molar feed ratio of 0.9. Both FTS and water-gas shift activities increase after the addition of 0.9 wt % potassium, whereas an opposite trend is observed with the addition of 2 wt % potassium. This is shown to be the result of interaction between the decrease of both the activation energy (E{sub a}) and the pre-exponental factor (k{sub 0}) with the amount of potassium promoter added. Detectable hydrocarbons up to C{sub 34} and oxygenates up to C{sub 5} are formed on the Fe/AC catalysts with or without potassium. The potassium promoter significantly suppresses formation of methane and methanol and shifts selectivities to higher-molecular-weight hydrocarbons (C{sub 5+}) and alcohols (C{sub 2}-C{sub 5}). Meanwhile, the potassium promoter changes paraffin and olefin distributions. At least for carbon numbers of 25 or less, increasing the K level to 0.9 wt % greatly decreases the amount of n-paraffins and internal olefins (i.e., those with the double bond in other than the terminal positions) and dramatically increases branched paraffins and 1-olefins, but a further increase in the K level shows little additional improvement. The addition of potassium changes the effect of temperature on the selectivity to oxygenates. In the absence of K, oxygenate selectivity decreases with temperature. However, when K is present, the selectivity is almost independent of the temperature. 71 refs., 13 figs., 3 tabs.

  2. Effect of Surface Modification by Chelating Agents on Fischer- Tropsch Performance of Co/SiO{sub 2} Catalysts

    SciTech Connect

    Bambal, Ashish S.; Kugler, Edwin L.; Gardner, Todd H.; Dadyburjor, Dady B.

    2013-11-14

    The silica support of a Co-based catalyst for Fischer-Tropsch (FT) synthesis was modified by the chelating agents (CAs) nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA). After the modification, characterization of the fresh and spent catalysts show reduced crystallite sizes, a better-dispersed Co₃O₄ phase on the calcined samples, and increased metal dispersions for the reduced samples. The CA-modified catalysts display higher CO conversions, product yields, reaction rates and rate constants. The improved FT performance of CA-modified catalysts is attributed to the formation of stable complexes with Co. The superior performance of the EDTA-modified catalyst in comparison to the NTA-modified catalyst is due to the higher affinity of the former for complex formation with Co ions.

  3. Fischer-Tropsch synthesis over MOF-supported cobalt catalysts (Co@MIL-53(Al)).

    PubMed

    Isaeva, V I; Eliseev, O L; Kazantsev, R V; Chernyshev, V V; Davydov, P E; Saifutdinov, B R; Lapidus, A L; Kustov, L M

    2016-07-26

    Novel nanohybrid materials were prepared by immobilizing Co nanoparticles on a microporous framework MIL-53(Al) as a porous host matrix. The synthesized cobalt-containing materials were characterized by XRD, STEM, and oxygen titration. The catalytic performance of Co@MIL-53(Al) nanohybrids was examined in Fischer-Tropsch synthesis (FTS) for the first time. A higher selectivity to C5+ hydrocarbons and lower selectivity to methane for Co@MIL-53(Al) as compared to conventional Co/Al2O3 were observed.

  4. Dynamics of carbide formation in iron-supported catalysts of the Fischer-Tropsch process promoted by copper and potassium

    NASA Astrophysics Data System (ADS)

    Kazak, V. O.; Pankina, G. V.; Chernavskii, P. A.; Lunin, V. V.

    2017-05-01

    The kinetics of the formation of iron carbides during the activation of iron-coated catalyst for Fischer-Tropsch synthesis promoted by copper and potassium, and by carbon monoxide and syngas, is studied. It is established that the presence of copper lowers the initial temperature of hematite reduction to magnetite and leads to the formation of carbide in both CO and CO/H2. Potassium slows the rate of magnetite formation, but it accelerates the formation of iron oxide. It is shown that the rate of carbide formation during magnetite reduction for catalysts is half that in the reaction of hematite reduction to magnetite in both CO and CO/H2.

  5. Selective synthesis and chain growth of linear hydrocarbons in the Fischer-Tropsch synthesis over zeolite-entrapped cobalt catalysts

    SciTech Connect

    Koh, D.J.; Chung, J.S.; Kim, Y.G.

    1995-06-01

    The impregnation of NaOH solution into the pores of cobalt-exchanged zeolite promoted the conventional reduction of cobalt ions with hydrogen gas. The method yielded catalysts that had high degrees of reduction and small cobalt clusters located inside zeolite pores. In the Fischer-Tropsch synthesis these catalysts showed a chain-extension effect, producing hydrocarbons higher than C{sub 10} in appreciable amounts, and an enhanced production of linear hydrocarbons such as 1-olefins and n-paraffins. The formation of long-chain hydrocarbons is attributed to an increased chance of the chain growth owing to a hold-up effect of reaction intermediates, especially 1-olefins, which are accumulated inside zeolite pores during the reaction. Hydrocarbon isomers are produced over acidic sites of zeolite by secondary reactions (isomerization and cracking), which result in a chain shortening of the long-chain hydrocarbons.

  6. The synthesis of Fe-Cu-Si oxide as a potential catalyst material for Fischer Tropsch reaction

    NASA Astrophysics Data System (ADS)

    Tjahjanto, Rachmat Triandi; Mustaqimah, Aili Millatul; Ayun, Qurratu

    2017-03-01

    Variations of iron(III) concentration were made during the synthesis of iron-copper-silicon oxide with sol-gel technique. The material was synthesized as a potential catalyst material for Fischer Tropsch reaction. A solution of sodium metasilicate was added dropwise onto solutions of iron(III) and copper(II) nitrate in diluted nitric acid. At pH 5 gels were obtained, followed with drying, calcination, and grinding to obtain fine powders. At concentration of iron(III) nitrate of 22.99% and 23.81% the process provided pale yellow colored powders, while those with 24.20%, 26.93%, and 27.58% of iron(III) nitrates gave brown powders. One of the brown powders showed crystalline phase in its diffractograms, while the yellow one was completely amorphous.

  7. Isotopic tracer studies of Fischer-Tropsch Synthesis over Ru/TiO2 catalysts

    SciTech Connect

    Krishna, Kamala Raghunathan

    1992-01-01

    Fischer-Tropsch synthesis is a process in which CO and H2 react to give predominantly liquid hydrocarbons. The reaction can be considered a special type of polymerization in which the monomer is produced in situ, and chain growth occurs by a sequence of independently repeated additions of the monomer to the growing chain. A investigation has been conducted to study the CO hydrogenation reaction in order to better understand catalyst deactivation and the elementary surface processes involved in chain growth. Isotopic tracers are used in conjunction with transient-response techniques in this study of Fischer-Tropsch synthesis over Ru/TiO2 catalysts. Experiments are conducted at a total pressure of 1 atmosphere, reaction temperatures of 453--498 K and D2/CO (or H2/CO) ratios of 2--5. Synthesis products are analyzed by gas chromatography or isotope-ratio gas chromatography-mass spectrometry. Rate constants for chain initiation, propagation and termination are evaluated under steady-state reaction conditions by using transients in isotopic composition. The activation energy for chain termination is much higher than that for propagation, accounting for the observed decrease in the chain growth parameter are also estimated. Coverages by reaction intermediates are also estimated. When small amounts of 12C-labelled ethylene are added to 13CO/H2 synthesis gas, ethylene acts as the sole chain initiator. Ethylene-derived carbon also accounts for 45% of the C1 monomer pool. 102 refs., 29 figs., 11 tabs.

  8. Nanocrystalline Ferrihydrite-Based Catalysts for Fischer-Tropsch Synthesis: Part II. Effects of Activation Gases on the Catalytic Performance.

    PubMed

    Rhim, Geun Bae; Hong, Seok Yong; Park, Ji Chan; Jung, Heon; Rhee, Young Woo; Chun, Dong Hyun

    2016-02-01

    Fischer-Tropsch synthesis (FTS) was carried out over nanocrystalline ferrihydrite-based (Fe9O2(OH)23) catalysts activated by different reducing agents: syngas (H2+CO), CO, and H2. The syngas activation successfully changed the ferrihydrite-based catalysts into an active and stable catalytic structure with chi-carbide (Fe2.5 C) and epsilon'-carbide (Fe2.2 C). The crystal structure of the catalysts obtained by syngas activation was similar to the structure obtained by CO activation; this similarity was probably due to the peculiar reduction behavior of the ferrihydrite-based catalysts, which exhibit much greater reducibility in CO atmosphere than in H2 atmosphere. The performance of the catalysts activated by syngas was much higher than the performance of the catalysts activated by H2 and was comparable to the performance of the catalysts activated by CO. This strongly demonstrates that the ferrihydrite-based catalysts are advantageous for industrial FTS processes because syngas can be commonly used for both activation pre-treatment and subsequent reaction.

  9. Shape-selective catalysts for Fischer-Tropsch chemistry. Final report : January 1, 2001 - December 31, 2008.

    SciTech Connect

    Cronauer, D. C.

    2011-04-11

    Argonne National Laboratory carried out a research program to create, prepare, and evaluate catalysts to promote Fischer-Tropsch (FT) chemistry-specifically, the reaction of hydrogen with carbon monoxide to form long-chain hydrocarbons. In addition to needing high activity, it was desirable that the catalysts have high selectivity and stability with respect to both mechanical strength and aging properties. It was desired that selectivity be directed toward producing diesel fraction components and avoiding excess yields of both light hydrocarbons and heavy waxes. The original goal was to produce shape-selective catalysts that had the potential to limit the formation of long-chain products and yet retain the active metal sites in a protected 'cage.' This cage would also restrict their loss by attrition during use in slurry-bed reactors. The first stage of this program was to prepare and evaluate iron-containing particulate catalysts. Such catalysts were prepared with silica-containing fractal cages. The activity and strength was essentially the same as that of catalysts without the cages. Since there was no improvement, the program plan was modified as discussed below. A second experimental stage was undertaken to prepare and evaluate active FT catalysts formed by atomic-layer deposition [ALD] of active components on supported membranes and particulate supports. The concept was that of depositing active metals (i.e. ruthenium, iron or cobalt) upon membranes with well defined flow channels of small diameter and length such that the catalytic activity and product molecular weight distribution could be controlled. In order to rapidly evaluate the catalytic membranes, the ALD coating processes were performed in an 'exploratory mode' in which ALD procedures from the literature appropriate for coating flat surfaces were applied to the high surface area membranes. Consequently, the Fe and Ru loadings in the membranes were likely to be smaller than those expected for

  10. IMPROVED IRON CATALYSTS FOR SLURRY PHASE FISCHER-TROPSCH SYNTHESIS

    SciTech Connect

    Dr. Dragomir B. Bukur; Dr. Lech Nowicki; Victor Carreto-Vazquez; Dr. Wen-Ping Ma

    2001-11-28

    PureVision Technology, Inc. (PureVision) of Fort Lupton, Colorado is developing a process for the conversion of lignocellulosic biomass into fuel-grade ethanol and specialty chemicals in order to enhance national energy security, rural economies, and environmental quality. Lignocellulosic-containing plants are those types of biomass that include wood, agricultural residues, and paper wastes. Lignocellulose is composed of the biopolymers cellulose, hemicellulose, and lignin. Cellulose, a polymer of glucose, is the component in lignocellulose that has potential for the production of fuel-grade ethanol by direct fermentation of the glucose. However, enzymatic hydrolysis of lignocellulose and raw cellulose into glucose is hindered by the presence of lignin. The cellulase enzyme, which hydrolyzes cellulose to glucose, becomes irreversibly bound to lignin. This requires using the enzyme in reagent quantities rather than in catalytic concentration. The extensive use of this enzyme is expensive and adversely affects the economics of ethanol production. PureVision has approached this problem by developing a biomass fractionator to pretreat the lignocellulose to yield a highly pure cellulose fraction. The biomass fractionator is based on sequentially treating the biomass with hot water, hot alkaline solutions, and polishing the cellulose fraction with a wet alkaline oxidation step. In September 2001 PureVision and Western Research Institute (WRI) initiated a jointly sponsored research project with the U.S. Department of Energy (DOE) to evaluate their pretreatment technology, develop an understanding of the chemistry, and provide the data required to design and fabricate a one- to two-ton/day pilot-scale unit. The efforts during the first year of this program completed the design, fabrication, and shakedown of a bench-scale reactor system and evaluated the fractionation of corn stover. The results from the evaluation of corn stover have shown that water hydrolysis prior to alkaline hydrolysis may be beneficial in removing hemicellulose and lignin from the feedstock. In addition, alkaline hydrolysis has been shown to remove a significant portion of the hemicellulose and lignin. The resulting cellulose can be exposed to a finishing step with wet alkaline oxidation to remove the remaining lignin. The final product is a highly pure cellulose fraction containing less than 1% of the native lignin with an overall yield in excess of 85% of the native cellulose. This report summarizes the results from the first year's effort to move the technology to commercialization.

  11. Evaluation of Reoxidation Thresholds for γ-Al2O3-Supported Cobalt Catalysts under Fischer-Tropsch Synthesis Conditions.

    PubMed

    Tsakoumis, Nikolaos E; Walmsley, John C; Rønning, Magnus; van Beek, Wouter; Rytter, Erling; Holmen, Anders

    2017-02-28

    Size-dependent phenomena at the nanoscale influence many applications, notably in the science of heterogeneous catalysis. In cobalt-based Fischer-Tropsch synthesis (FTS), the size of Co nanoparticles (NPs) dictates to a high degree catalyst's performance in terms of activity, selectivity, and stability. Here, a highly dispersed Re/Co/γ-Al2O3 catalyst with high Co surface area per gram of catalyst was exposed to industrially relevant FTS conditions and monitored in situ by synchrotron X-ray radiation. X-ray absorption near-edge structure spectra were obtained on the cobalt K edge and Re L3 edge of the working catalyst. The experimental results demonstrate development of tetrahedrally coordinated Co(2+) forming at the expense of metallic Co((0)). The structure of the oxide resembles CoAl2O4 and appears at the onset (first 5-10 h) of the reaction. Reoxidation of Co((0)) is more pronounced close to the outlet of the reactor, where higher pH2O is anticipated. The state of the Re promoter does not change during the FT process. We propose that reoxidation of small Co NPs is followed by spreading of Co oxide that leads to the formation of CoxAlyOz phases. Hence, in order to avoid an irreversible loss of the active phase during process start-up, catalyst design should be restricted to Co NPs larger than 5.3 nm.

  12. Effect of Potassium Addition on Coprecipitated Iron Catalysts for Fischer-Tropsch Synthesis Using Bio-oil-syngas

    NASA Astrophysics Data System (ADS)

    Wang, Zhao-xiang; Dong, Ting; Kan, Tao; Li, Quan-xin

    2008-04-01

    The effects of potassium addition and the potassium content on the activity and selectivity of coprecipitated iron catalyst for Fischer-Tropsch synthesis (FTS) were studied in a fixed bed reactor at 1.5 MPa, 300°C, and contact time (W/F) of 12.5 gcath/mol using the model bio-oil-syngas of H2/CO/CO2/N2 (62/8/25/5, vol%). It was found that potassium addition increases the catalyst activity for FTS and the reverse water gas shift reaction. Moreover, potassium increases the average molecular weight (chain length) of the hydrocarbon products. With the increase of potassium content, it was found that CH4 selectivity decreases and the selectivity of liquid phase products (C5+) increases. The characteristics of FTS catalysts with different potassium content were also investigated by various characterization measurements including X-ray diffraction, X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller surface area. Based on experimental results, 100Fe/6Cu/16Al/6K (weight ratio) was selected as the optimal catalyst for FTS from bio-oil-syngas. The results indicate that the 100Fe/6Cu/16Al/6K catalyst is one of the most promising candidates to directly synthesize liquid bio-fuel using bio-oil-syngas.

  13. The effects of promoters of K and Zr on the mesoporous carbon supported cobalt catalysts for Fischer-Tropsch synthesis.

    PubMed

    Chen, Liang; Song, Guoxia; Fu, Yuchuan; Shen, Jianyi

    2012-02-15

    The mesoporous carbon supported cobalt catalyst (15%Co/MC) was found to be more active and selective to C(5)(+) than the traditionally activated carbon supported one (15%Co/AC) for the Fischer-Tropsch synthesis (FTS). The addition of small amount of K(2)O and ZrO(2) significantly affected the FTS behavior of 15%Co/MC. The addition of 1% K inhibited the FTS activity dramatically, while the addition of 3% Zr increased the FTS activity significantly. The addition of K(2)O decreased the surface acidity while increased the surface basicity of 15%Co/MC, resulting in the increased heat of adsorption of CO and substantially decreased heat of adsorption of H(2) on Co. In contrast, the addition of ZrO(2) increased the surface acidity and heat of adsorption of H(2) on Co. The FTS activity was found to be related to the ratio of heats for the adsorption of CO and H(2) on the catalysts 15%Co/MC, 15%Co-1%K/MC and 15%Co-3%Zr/MC. The highest FTS activity was obtained on the catalyst with the heat ratio of 1.2. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Separation of Fischer-Tropsch Wax Products from Ultrafine Iron Catalyst Particles

    SciTech Connect

    James K. Neathery; Gary Jacobs; Amitava Sarkar; Adam Crawford; Burtron H. Davis

    2006-09-30

    In the previous reporting period, modifications were completed for integrating a continuous wax filtration system for a 4 liter slurry bubble column reactor. During the current reporting period, a shakedown of the system was completed. Several problems were encountered with the progressive cavity pump used to circulate the wax/catalyst slurry though the cross-flow filter element and reactor. During the activation of the catalyst with elevated temperature (> 270 C) the elastomer pump stator released sulfur thereby totally deactivating the iron-based catalyst. Difficulties in maintaining an acceptable leak rate from the pump seal and stator housing were also encountered. Consequently, the system leak rate exceeded the expected production rate of wax; therefore, no online filtration could be accomplished. Work continued regarding the characterization of ultra-fine catalyst structures. The effect of carbidation on the morphology of iron hydroxide oxide particles was the focus of the study during this reporting period. Oxidation of Fe (II) sulfate results in predominantly {gamma}-FeOOH particles which have a rod-shaped (nano-needles) crystalline structure. Carbidation of the prepared {gamma}-FeOOH with CO at atmospheric pressure produced iron carbides with spherical layered structure. HRTEM and EDS analysis revealed that carbidation of {gamma}-FeOOH particles changes the initial nano-needles morphology and generates ultrafine carbide particles with irregular spherical shape.

  15. Liquid phase Fischer-Tropsch (II) demonstration in the Laporte Alternative Fuels Development Unit. Final topical report. Volume 7, Appendix. Task 1, Engineering modifications (Fischer-Tropsch II demonstration) and Task 2, AFDU shakedown, operations, deactivation and disposal (Fischer-Tropsch II demonstration)

    SciTech Connect

    Bhatt, B.L.

    1995-09-01

    This report presents results from a demonstration of Liquid Phase Fischer-Tropsch (LPFT) technology in DOE`s Alternative Fuels Development Unit (AFDU) at LaPorte, Texas. The run was conducted in a bubble column at the AFDU in May--June 1994. The 10-day run demonstrated a very high level of reactor productivity for LPFT, more than five times the previously demonstrated productivity (1). The productivity was constrained by mass transfer limitations, perhaps due to slurry thickening as a result of carbon formation on the catalyst. With a cobalt catalyst or an improved iron catalyst, if the carbon formation can be avoided, there is significant room for further improvements. This volume contains appendices for: reactor temperature stability; Mott Cross-flow filter test for F-T II; Fischer-Tropsch II run authorizations; Fischer-Tropsch II run chronology; liquid compositions; and F-T II / IIA Demonstration Mass Balances.

  16. Performance characterization of CNTs and γ-Al2O3 supported cobalt catalysts in Fischer-Tropsch reaction

    NASA Astrophysics Data System (ADS)

    Ali, Sardar; Zabidi, Noor Asmawati Mohd; Subbarao, Duvvuri

    2014-10-01

    Catalysts were prepared via a wet impregnation method. Different physicochemical properties of the samples were revealed by transmission electron microscope (TEM), temperature programmed reduction (H2-TPR) and carbon dioxide desorption (CO2-desorption). Fischer-Tropsch reaction (FTS) was carried out in a fixed-bed microreactor at 220°C and 1 atm, with H2/ CO = 2v / v and space velocity, SV of 12L/g.h for 5 h. Various characterization techniques revealed that there was a stronger interaction between Co and Al2O3 support compared to that of CNTs support. CNTs support increased the reducibility and decreased Co particle size. A significant increase in % CO conversion and FTS reaction rate was observed over CNTs support compared to that of Co / Al2O3. Co/CNTs resulted in higher C5+ hydrocarbons selectivity compared to that of Co / Al2O3 catalyst. CNTs are a better support for Co compared to Al2O3.

  17. Mechanism of promotion of iron Fischer-Tropsch catalysts: Quarterly report for period ending March 31, 1986

    SciTech Connect

    1986-01-01

    The Fischer-Tropsch reaction is a complex combination of many reactions. Among those that have been demonstrated to occur on the catalyst surface are CO dissociation, build-up of carbon chains by a polymerization process, desorption of products such as olefins and oxygen-containing compounds, water formation and its subsequent shift reaction to form CO/sub 2/, olefin hydrogenation, isomerization and reincorporation in the synthesis and, probably, other reactions yet to be identified and studied. The tracer technique, involving the feeding of /sup 14/C-labled compounds to the synthesis, is being used here in an effort to learn how catalyst additives and supports influence these reactions and determine the final product distribution. /sup 14/C labeled ethanol, when added to a CO/H/sub 2/ feed, undergoes dehydrogenation to establish essentially an equilibrium ethanol-acetaldehyde mixture. However, under the reaction conditions used, ethyl acetate and 1,1-diethoxyethane (actual) are significant products; the /sup 14/C label permits use to identify these products as being derived from ethanol. In addition, it appears that aldol condensation of acetaldehyde occurs to a minor extent. 28 refs., 17 figs., 1 tab.

  18. Size and Promoter Effects on Stability of Carbon-Nanofiber-Supported Iron-Based Fischer-Tropsch Catalysts.

    PubMed

    Xie, Jingxiu; Torres Galvis, Hirsa M; Koeken, Ard C J; Kirilin, Alexey; Dugulan, A Iulian; Ruitenbeek, Matthijs; de Jong, Krijn P

    2016-06-03

    The Fischer-Tropsch Synthesis converts synthesis gas from alternative carbon resources, including natural gas, coal, and biomass, to hydrocarbons used as fuels or chemicals. In particular, iron-based catalysts at elevated temperatures favor the selective production of C2-C4 olefins, which are important building blocks for the chemical industry. Bulk iron catalysts (with promoters) were conventionally used, but these deactivate due to either phase transformation or carbon deposition resulting in disintegration of the catalyst particles. For supported iron catalysts, iron particle growth may result in loss of catalytic activity over time. In this work, the effects of promoters and particle size on the stability of supported iron nanoparticles (initial sizes of 3-9 nm) were investigated at industrially relevant conditions (340 °C, 20 bar, H2/CO = 1). Upon addition of sodium and sulfur promoters to iron nanoparticles supported on carbon nanofibers, initial catalytic activities were high, but substantial deactivation was observed over a period of 100 h. In situ Mössbauer spectroscopy revealed that after 20 h time-on-stream, promoted catalysts attained 100% carbidization, whereas for unpromoted catalysts, this was around 25%. In situ carbon deposition studies were carried out using a tapered element oscillating microbalance (TEOM). No carbon laydown was detected for the unpromoted catalysts, whereas for promoted catalysts, carbon deposition occurred mainly over the first 4 h and thus did not play a pivotal role in deactivation over 100 h. Instead, the loss of catalytic activity coincided with the increase in Fe particle size to 20-50 nm, thereby supporting the proposal that the loss of active Fe surface area was the main cause of deactivation.

  19. Chemical Insights into the Design and Development of Face-Centered Cubic Ruthenium Catalysts for Fischer-Tropsch Synthesis.

    PubMed

    Li, Wei-Zhen; Liu, Jin-Xun; Gu, Jun; Zhou, Wu; Yao, Si-Yu; Si, Rui; Guo, Yu; Su, Hai-Yan; Yan, Chun-Hua; Li, Wei-Xue; Zhang, Ya-Wen; Ma, Ding

    2017-02-15

    Ruthenium is a promising low-temperature catalyst for Fischer-Tropsch synthesis (FTS). However, its scarcity and modest specific activity limit its widespread industrialization. We demonstrate here a strategy for tuning the crystal phase of catalysts to expose denser and active sites for a higher mass-specific activity. Density functional theory calculations show that upon CO dissociation there are a number of open facets with modest barrier available on the face-centered cubic (fcc) Ru but only a few step edges with a lower barrier on conventional hexagonal-closest packed (hcp) Ru. Guided by theoretical calculations, water-dispersible fcc Ru catalysts containing abundant open facets were synthesized and showed an unprecedented mass-specific activity in the aqueous-phase FTS, 37.8 molCO·molRu(-1)·h(-1) at 433 K. The mass-specific activity of the fcc Ru catalysts with an average size of 6.8 nm is about three times larger than the previous best hcp catalyst with a smaller size of 1.9 nm and a higher specific surface area. The origin of the higher mass-specific activity of the fcc Ru catalysts is identified experimentally from the 2 orders of magnitude higher density of the active sites, despite its slightly higher apparent barrier. Experimental results are in excellent agreement with prediction of theory. The great influence of the crystal phases on site distribution and their intrinsic activities revealed here provides a rationale design of catalysts for higher mass-specific activity without decrease of the particle size.

  20. Separation of Fischer-Tropsch Wax Products from Ultrafine Iron Catalyst Particles

    SciTech Connect

    James K. Neathery; Gary Jacobs; Amitava Sarkar; Burtron H. Davis

    2006-03-31

    The morphological and chemical nature of ultrafine iron catalyst particles (3-5 nm diameters) during activation/FTS was studied by HRTEM, EELS, and Moessbauer spectroscopy. With the progress of FTS, the carbide re-oxidized to magnetite and catalyst activity gradually decreased. The growth of oxide phase continued and average particle size also increased simultaneously. The phase transformation occurred in a ''growing oxide core'' manner with different nano-zones. The nano-range carbide particles did not show fragmentation or attrition as generally observed in micrometer range particles. Nevertheless, when the dimension of particles reached the micrometer range, the crystalline carbide phase appeared to be sprouted on the surface of magnetite single crystal. In the previous reporting period, a design and operating philosophy was developed for an integrated wax filtration system for a 4 liter slurry bubble column reactor to be used in Phase II of this research program. During the current reporting period, we have started construction of the new filtration system and began modifications to the 4 liter slurry bubble column reactor (SBCR) reactor. The system will utilize a primary wax separation device followed by a Pall Accusep or Membralox ceramic cross-flow membrane. As of this writing, the unit is nearly complete except for the modification of a moyno-type pump; the pump was shipped to the manufacturer to install a special leak-free, high pressure seal.

  1. Structural and elemental influence from various MOFs on the performance of Fe@C catalysts for Fischer-Tropsch synthesis.

    PubMed

    Wezendonk, Tim A; Warringa, Quirinus S E; Santos, Vera P; Chojecki, Adam; Ruitenbeek, Matthijs; Meima, Garry; Makkee, Michiel; Kapteijn, Freek; Gascon, Jorge

    2017-02-14

    The structure and elementary composition of various commercial Fe-based MOFs used as precursors for Fischer-Tropsch synthesis (FTS) catalysts have a large influence on the high-temperature FTS activity and selectivity of the resulting Fe on carbon composites. The selected Fe-MOF topologies (MIL-68, MIL-88A, MIL-100, MIL-101, MIL-127, and Fe-BTC) differ from each other in terms of porosity, surface area, Fe and heteroatom content, crystal density and thermal stability. They are re-engineered towards FTS catalysts by means of simple pyrolysis at 500 °C under a N2 atmosphere and afterwards characterized in terms of porosity, crystallite phase, bulk and surface Fe content, Fe nanoparticle size and oxidation state. We discovered that the Fe loading (36-46 wt%) and nanoparticle size (3.6-6.8 nm) of the obtained catalysts are directly related to the elementary composition and porosity of the initial MOFs. Furthermore, the carbonization leads to similar surface areas for the C matrix (SBET between 570 and 670 m(2) g(-1)), whereas the pore width distribution is completely different for the various MOFs. The high catalytic performance (FTY in the range of 1.9-4.6 × 10(-4) molCO gFe(-1) s(-1)) of the resulting materials could be correlated to the Fe particle size and corresponding surface area, and only minor deactivation was found for the N-containing catalysts. Elemental analysis of the catalysts containing deliberately added promoters and inherent impurities from the commercial MOFs revealed the subtle interplay between Fe particle size and complex catalyst composition in order to obtain high activity and stability next to a low CH4 selectivity.

  2. Sulfated zirconia as a CO-catalyst for the production of branched hydrocarbons via Fischer-Tropsch synthesis

    SciTech Connect

    Song, S.; Savari, A.

    1995-12-01

    This communication deals with the direct synthesis of branched hydrocarbons from synthesis gas using a two-component catalyst: a sulfated zirconia (SO{sub 4}{sup 2-}/ZrO{sub 2}) superacid and a Fischer-Tropsch synthesis catalyst (2% RuKY). The composition of C{sub 7} hydrocarbons was used to monitor the effect of SO{sub 4} {sup 2-}/ZrO{sub 2} on product selectivity. Over pure 2% RuKY, at P = 10 atm. and T = 250{degrees}C, the content of branched C{sub 7} in total C{sub 7} hydrocarbons (iC{sub 7}%) was below 10 wt.%, while that of C{sub 7} olefins was very high (C{sub 7}{sup =}% = 67 wt.%). When SO{sub 4}{sup 2-} was loaded downstream of the 2% RuKY catalyst, the production amounts of olefins were of iC{sub 7} hydrocarbons increased significantly (67 wt.%), while only negligible amounts of olefins were produced in the early stages of the reaction. However, during the subsequent deactivation of SO{sub 4}{sup 2-}/ZrO{sub 2} catalyst, the production of iC{sub 7} decreased and that of C{sub 7}{sup =} increased. Addition of ca. 1 wt.% of platinum to SO{sub 4}{sup 2-}/ZrO{sub 2} improved its stability. Under steady state, the iC{sub 7}% and C{sub 7}{sup =}% fractions reached 50% and 20%, respectively. The deactivation of sulfated zirconia was interpreted in terms of coking and effect of CO on the catalyst acidity. In addition, the effects of operational conditions (pressure, H{sub 2}/CO ratio, ratio of catalyst components, and Pt content) will be discussed.

  3. Fischer-Tropsch Wastewater Utilization

    DOEpatents

    Shah, Lalit S.

    2003-03-18

    The present invention is generally directed to handling the wastewater, or condensate, from a hydrocarbon synthesis reactor. More particularly, the present invention provides a process wherein the wastewater of a hydrocarbon synthesis reactor, such as a Fischer-Tropsch reactor, is sent to a gasifier and subsequently reacted with steam and oxygen at high temperatures and pressures so as to produce synthesis gas. The wastewater may also be recycled back to a slurry preparation stage, where solid combustible organic materials are pulverized and mixed with process water and the wastewater to form a slurry, after which the slurry fed to a gasifier where it is reacted with steam and oxygen at high temperatures and pressures so as to produce synthesis gas.

  4. Shape-selective catalysts for Fischer-Tropsch chemistry : iron-containing particulate catalysts. Activity report : January 1, 2001 - December 31, 2004.

    SciTech Connect

    Cronauer, D.; Chemical Engineering

    2006-05-12

    Argonne National Laboratory is carrying out a research program to create, prepare, and evaluate catalysts to promote Fischer-Tropsch (FT) chemistry--specifically, the reaction of hydrogen with carbon monoxide to form long-chain hydrocarbons. In addition to needing high activity, it is desirable that the catalysts have high selectivity and stability with respect to both mechanical strength and aging properties. It is desired that selectivity be directed toward producing diesel fraction components and avoiding excess yields of both light hydrocarbons and heavy waxes. The goal is to produce shape-selective catalysts that have the potential to limit the formation of longchain products and yet retain the active metal sites in a protected 'cage'. This cage also restricts their loss by attrition during use in slurry-bed reactors. The first stage of this program was to prepare and evaluate iron-containing particulate catalysts. This activity report centers upon this first stage of experimentation with particulate FT catalysts. (For reference, a second experimental stage is under way to prepare and evaluate active FT catalysts formed by atomic-layer deposition [ALD] of active components on supported membranes.) To date, experimentation has centered upon the evaluation of a sample of iron-based, spray-dried catalyst prepared by B.H. Davis of the Center of Applied Energy Research (CAER) and samples of his catalyst onto which inorganic 'shells' were deposited. The reference CAER catalyst contained a high level of dispersed fine particles, a portion of which was removed by differential settling. Reaction conditions have been established using a FT laboratory unit such that reasonable levels of CO conversion can be achieved, where therefore a valid catalyst comparison can be made. A wide range of catalytic activities was observed with SiO{sub 2}-coated FT catalysts. Two techniques were used for SiO{sub 2}coating. The first involved a caustic precipitation of SiO{sub 2} from an

  5. The effect of the nanofibrous Al2O3 aspect ratio on Fischer-Tropsch synthesis over cobalt catalysts.

    PubMed

    Liu, Chengchao; Zhang, Yuhua; Zhao, Yanxi; Wei, Liang; Hong, Jingping; Wang, Li; Chen, Sufang; Wang, Guanghui; Li, Jinlin

    2017-01-05

    A series of nanofibrous alumina materials with diameters of 4-6 nm and with different aspect ratios ranging from 3 to 16 were prepared. Cobalt impregnated catalysts were prepared by means of incipient wetness impregnation on alumina nanofibers while the 'rearranged' catalysts were prepared by using ultrasonication assistance to mix the fibers with the Co3O4 nanoparticles. The effects of the alumina nanofiber aspect ratios on the Co catalyst structure and performance for Fischer-Tropsch synthesis were studied. The pore size of the two series of catalysts increased as the aspect ratio of the alumina nanofiber increased. For impregnated catalysts, large Co3O4 particles were formed on the external surface of the alumina support when the aspect ratio was 3 and 5, while the crystallite sizes of Co3O4 increased from 13.3 nm to 15.6 nm with the increase of the aspect ratio from 7 to 16. The four 'rearranged' catalysts possessed similar and homogeneously dispersed Co3O4 crystallites of 9.5 nm. As expected the reduction behavior of the two series of catalysts was primarily influenced by the Co3O4 crystallite size and structure. The FT data of the two series of catalysts indicate that dispersed Co catalysts on alumina nanofibers with large aspect ratios having large inter-crystallite pores significantly improve the catalyst activity and C5+ selectivity. The FT data of the 'rearranged' catalysts strongly demonstrated that the internal mass transfer of reactants and products increased with a decrease in inter-crystallite pore size, resulting in a decrease of C5+ selectivity and C3 olefin/paraffin ratio, and an increase of CH4 selectively, while the CO consumption rate was little altered. Furthermore, catalytic stability tests showed that the alumina nanofibers with larger aspect ratios inhibited Co migration and coalescence in the matrices of the nanofibrous alumina, and this significantly enhanced the stability of the catalyst. The Cop/Al2O3-16 catalyst possessing uniformly

  6. Atomic-Scale Design of Iron Fischer-Tropsch Catalysts: A Combined Computational Chemistry, Experimental, and Microkinetic Modeling Approach

    SciTech Connect

    Manos Mavrikakis; James A. Dumesic; Rahul P. Nabar

    2006-09-29

    Work continued on the development of a microkinetic model of Fischer-Tropsch synthesis (FTS) on supported and unsupported Fe catalysts. The following aspects of the FT mechanism on unsupported iron catalysts were investigated on during this third year: (1) the collection of rate data in a Berty CSTR reactor based on sequential design of experiments; (2) CO adsorption and CO-TPD for obtaining the heat of adsorption of CO on polycrystalline iron; and (3) isothermal hydrogenation (IH) after Fischer Tropsch reaction to identify and quantify surface carbonaceous species. Rates of C{sub 2+} formation on unsupported iron catalysts at 220 C and 20 atm correlated well to a Langmuir-Hinshelwood type expression, derived assuming carbon hydrogenation to CH and OH recombination to water to be rate-determining steps. From desorption of molecularly adsorbed CO at different temperatures the heat of adsorption of CO on polycrystalline iron was determined to be 100 kJ/mol. Amounts and types of carbonaceous species formed after FT reaction for 5-10 minutes at 150, 175, 200 and 285 C vary significantly with temperature. Mr. Brian Critchfield completed his M.S. thesis work on a statistically designed study of the kinetics of FTS on 20% Fe/alumina. Preparation of a paper describing this work is in progress. Results of these studies were reported at the Annual Meeting of the Western States Catalysis and at the San Francisco AIChE meeting. In the coming period, studies will focus on quantitative determination of the rates of kinetically-relevant elementary steps on unsupported Fe catalysts with/without K and Pt promoters by SSITKA method. This study will help us to (1) understand effects of promoter and support on elementary kinetic parameters and (2) build a microkinetics model for FTS on iron. Calculations using periodic, self-consistent Density Functional Theory (DFT) methods were performed on models of defected Fe surfaces, most significantly the stepped Fe(211) surface. Binding

  7. Evidence of highly active cobalt oxide catalyst for the Fischer-Tropsch synthesis and CO2 hydrogenation.

    PubMed

    Melaet, Gérôme; Ralston, Walter T; Li, Cheng-Shiuan; Alayoglu, Selim; An, Kwangjin; Musselwhite, Nathan; Kalkan, Bora; Somorjai, Gabor A

    2014-02-12

    Hydrogenations of CO or CO2 are important catalytic reactions as they are interesting alternatives to produce fine chemical feedstock hence avoiding the use of fossil sources. Using monodisperse nanoparticle (NP) catalysts, we have studied the CO/H2 (i.e., Fischer-Tropsch synthesis) and CO2/H2 reactions. Exploiting synchrotron based in situ characterization techniques such as XANES and XPS, we were able to demonstrate that 10 nm Co NPs cannot be reduced at 250 °C while supported on TiO2 or SiO2 and that the complete reduction of cobalt can only be achieved at 450 °C. Interestingly, cobalt oxide performs better than fully reduced cobalt when supported on TiO2. In fact, the catalytic results indicate an enhancement of 10-fold for the CO2/H2 reaction rate and 2-fold for the CO/H2 reaction rate for the Co/TiO2 treated at 250 °C in H2 versus Co/TiO2 treated at 450 °C. Inversely, the activity of cobalt supported on SiO2 has a higher turnover frequency when cobalt is metallic. The product distributions could be tuned depending on the support and the oxidation state of cobalt. For oxidized cobalt on TiO2, we observed an increase of methane production for the CO2/H2 reaction whereas it is more selective to unsaturated products for the CO/H2 reaction. In situ investigation of the catalysts indicated wetting of the TiO2 support by CoO(x) and partial encapsulation of metallic Co by TiO(2-x).

  8. ATOMIC-SCALE DESIGN OF IRON FISCHER-TROPSCH CATALYSTS: A COMBINED COMPUTATIONAL CHEMISTRY, EXPERIMENTAL, AND MICROKINETIC MODELING APPROACH

    SciTech Connect

    Manos Mavrikakis; James A. Dumesic; Amit A. Gokhale; Rahul P. Nabar; Calvin H. Bartholomew; Hu Zou; Brian Critchfield

    2005-03-22

    Efforts during this first year focused on four areas: (1) searching/summarizing published FTS mechanistic and kinetic studies of FTS reactions on iron catalysts; (2) construction of mass spectrometer-TPD and Berty CSTR reactor systems; (3) preparation and characterization of unsupported iron and alumina-supported iron catalysts at various iron loadings (4) Determination of thermochemical parameters such as binding energies of reactive intermediates, heat of FTS elementary reaction steps, and kinetic parameters such as activation energies, and frequency factors of FTS elementary reaction steps on a number of model surfaces. Literature describing mechanistic and kinetic studies of Fischer-Tropsch synthesis on iron catalysts was compiled in a draft review. Construction of the mass spectrometer-TPD system is 90% complete and of a Berty CSTR reactor system 98% complete. Three unsupported iron catalysts and three alumina-supported iron catalysts were prepared by nonaqueous-evaporative deposition (NED) or aqueous impregnation (AI) and characterized by chemisorption, BET, extent-of-reduction, XRD, and TEM methods. These catalysts, covering a wide range of dispersions and metal loadings, are well-reduced and relatively thermally stable up to 500-600 C in H{sub 2}, thus ideal for kinetic and mechanistic studies. The alumina-supported iron catalysts will be used for kinetic and mechanistic studies. In the coming year, adsorption/desorption properties, rates of elementary steps, and global reaction rates will be measured for these catalysts, with and without promoters, providing a database for understanding effects of dispersion, metal loading, and support on elementary kinetic parameters and for validation of computational models that incorporate effects of surface structure and promoters. Furthermore, using state-of-the-art self-consistent Density Functional Theory (DFT) methods, we have extensively studied the thermochemistry and kinetics of various elementary steps on

  9. Effect of Thermal Treatment on Structure and Catalytic Activity of Supported Fischer-Tropsch Nano-Cobalt Catalysts for Clean Fuels

    NASA Astrophysics Data System (ADS)

    Chu, Wei; Hong, J. P.; Payen, E.; Dai, X. Y.

    2007-12-01

    A series of 15%Co/Al2O3 catalysts were prepared by incipient wetness impregnation under various calcination conditions (90-500°C), and were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy experiments (XPS), temperature programmed reduction, and catalytic measurements of hydrogenation of carbon monoxide to long-chained hydrocarbons leading to clean fuels (Fischer-Tropsch synthesis). The results of XPS show the presence of incompletely decomposed cobalt nitrate for catalysts calcined at 90-200°C, and the presence of Co3O4 for catalysts calcined at 200-500°C. For the four alumina-supported nano-cobalt catalysts with different thermal treatment (200-500°C), XRD and XPS results illustrated that there were mainly nano Co3O4 crystalite phases of 9-10 nm and the size of cobalt nano-particles did almost not change with the different temperature of thermal treatment. This was different from that of silica-supported cobalt catalysts. The supported cobalt catalyst (CoAp340 sample) calcinated at 340°C presented a better activity for Fischer Tropsch synthesis to clean fuels, at mild conditions like atmospheric pressure (100 kPa), 1800 mL/g/h and 190°C rather than high pressure (2 MPa or more).

  10. Reducing fischer-tropsch catalyst attrition losses in high agitation reaction systems

    DOEpatents

    Singleton, Alan H.; Oukaci, Rachid; Goodwin, James G.

    2001-01-01

    A method for reducing catalyst attrition losses in hydrocarbon synthesis processes conducted in high agitation reaction systems; a method of producing an attrition-resistant catalyst; a catalyst produced by such method; a method of producing an attrition-resistant catalyst support; and a catalyst support produced by such method. The inventive method of reducing catalyst attrition losses comprises the step of reacting a synthesis gas in a high agitation reaction system in the presence of a catalyst. In one aspect, the catalyst preferably comprises a .gamma.-alumina support including an amount of titanium effective for increasing the attrition resistance of the catalyst. In another aspect, the catalyst preferably comprises a .gamma.-alumina support which has been treated, after calcination, with an acidic, aqueous solution. The acidic aqueous solution preferably has a pH of not more than about 5. In another aspect, the catalyst preferably comprises cobalt on a .gamma.-alumina support wherein the cobalt has been applied to the .gamma.-alumina support by totally aqueous, incipient wetness-type impregnation. In another aspect, the catalyst preferably comprises cobalt on a .gamma.-alumina support with an amount of a lanthana promoter effective for increasing the attrition resistance of the catalyst. In another aspect, the catalyst preferably comprises a .gamma.-alumina support produced from boehmite having a crystallite size, in the 021 plane, in the range of from about 30 to about 55 .ANG.ngstrons. In another aspect, the inventive method of producing an attrition-resistant catalyst comprises the step of treating a .gamma.-alumina support, after calcination of and before adding catalytic material to the support, with an acidic solution effective for increasing the attrition resistance of the catalyst. In another aspect, the inventive method of producing an attrition-resistant catalyst support comprises the step of treating calcined .gamma.-alumina with an acidic, aqueous

  11. Fischer-Tropsch activity for non-promoted cobalt-on-alumina catalysts

    DOEpatents

    Singleton, Alan H.; Oukaci, Rachid; Goodwin, James G.

    2001-01-01

    Cobalt catalysts, and processes employing these inventive catalysts, for hydrocarbon synthesis. The inventive catalyst comprises cobalt on an alumina support and is not promoted with any noble or near noble metals. In one aspect of the invention, the alumina support preferably includes a dopant in an amount effective for increasing the activity of the inventive catalyst. The dopant is preferably a titanium dopant. In another aspect of the invention, the cobalt catalyst is preferably reduced in the presence of hydrogen at a water vapor partial pressure effective to increase the activity of the cobalt catalyst for hydrocarbon synthesis. The water vapor partial pressure is preferably in the range of from 0 to about 0.1 atmospheres.

  12. Atomic-Scale Design of Iron Fischer-Tropsch Catalysts; A Combined Computational Chemistry, Experimental, and Microkinetic Modeling Approach

    SciTech Connect

    Manos Mavrikakis; James Dumesic; Rahul Nabar; Calvin Bartholonew; Hu Zou; Uchenna Paul

    2008-09-29

    This work focuses on (1) searching/summarizing published Fischer-Tropsch synthesis (FTS) mechanistic and kinetic studies of FTS reactions on iron catalysts; (2) preparation and characterization of unsupported iron catalysts with/without potassium/platinum promoters; (3) measurement of H{sub 2} and CO adsorption/dissociation kinetics on iron catalysts using transient methods; (3) analysis of the transient rate data to calculate kinetic parameters of early elementary steps in FTS; (4) construction of a microkinetic model of FTS on iron, and (5) validation of the model from collection of steady-state rate data for FTS on iron catalysts. Three unsupported iron catalysts and three alumina-supported iron catalysts were prepared by non-aqueous-evaporative deposition (NED) or aqueous impregnation (AI) and characterized by chemisorption, BET, temperature-programmed reduction (TPR), extent-of-reduction, XRD, and TEM methods. These catalysts, covering a wide range of dispersions and metal loadings, are well-reduced and relatively thermally stable up to 500-600 C in H{sub 2} and thus ideal for kinetic and mechanistic studies. Kinetic parameters for CO adsorption, CO dissociation, and surface carbon hydrogenation on these catalysts were determined from temperature-programmed desorption (TPD) of CO and temperature programmed surface hydrogenation (TPSR), temperature-programmed hydrogenation (TPH), and isothermal, transient hydrogenation (ITH). A microkinetic model was constructed for the early steps in FTS on polycrystalline iron from the kinetic parameters of elementary steps determined experimentally in this work and from literature values. Steady-state rate data were collected in a Berty reactor and used for validation of the microkinetic model. These rate data were fitted to 'smart' Langmuir-Hinshelwood rate expressions derived from a sequence of elementary steps and using a combination of fitted steady-state parameters and parameters specified from the transient

  13. Fischer Tropsch synthesis : influence of Mn on the carburization rates and activities of Fe-based catalysts by TPR-EXAFS/XANES and catalyst testing.

    SciTech Connect

    Ribeiro, M. C.; Jacobs, G.; Pendyala, R.; Davis, B. H.; Cronauer, D. C.; Kropf, A. J.; Marshall, C. L.

    2011-03-24

    Fe-based catalysts containing different amounts of Mn were tested for Fischer-Tropsch synthesis using a stirred tank reactor at 270 C, 1.21 MPa, and H{sub 2}:CO = 0.7. Catalyst activation by carburization with 10% CO/He was followed by Temperature Programmed Reduction/X-ray Absorption Spectroscopy (TPR-EXAFS/XANES) from room temperature to 300 C. {gamma}-Fe{sub 2}O{sub 3} was converted into iron carbides, whereas MnO{sub x} was reduced to oxygen deficient MnO. Mn hindered Fe carburization, such that the carburized catalyst displayed higher Fe{sub 3}O{sub 4} content than the catalyst without Mn. EXAFS fitting indicates that the carburized catalyst contained a mixture of Hgg carbide, Fe{sub 3}O{sub 4}, and Mn oxides. Increasing Mn content led to higher CH{sub 4} and light product selectivities, and lower light olefin selectivities. Higher and stable conversions were obtained with a catalyst containing an almost equimolar Fe/Mn ratio relative to the catalyst without Mn. Selectivity trends are attributed to the higher WGS rates observed on the FeMn catalysts, consistent with the structural differences observed.

  14. Particle size effect for cobalt Fischer-Tropsch catalysts based on in situ CO chemisorption

    NASA Astrophysics Data System (ADS)

    Yang, Jia; Frøseth, Vidar; Chen, De; Holmen, Anders

    2016-06-01

    The cobalt particle size effect on activity and selectivity for CO hydrogenation was revisited on cobalt catalysts supported on a large variety of supports at 483 K, 1.85 bar, and H2/CO/Ar = 15/1.5/33.5 Nml/min. The size dependence of the activity and selectivity was analyzed in terms of site coverage and rate constants based on SSITKA experimental results. It was found that the Co particle size index estimated by the conventional method, namely, ex situ hydrogen chemisorption, could not correlate well the activity and selectivity as a function of the particle size index. The same holds for the site coverage of CO and intermediates leading to methane formation. However, the cobalt particle size index based on in situ CO chemisorption measured at 373 K provides a good correlation for turnover frequencies (TOFs) at reaction conditions. It was observed that TOF for CO conversion (TOFCO) increased with increasing particle size index of cobalt and SSITKA experiments showed that this was possibly due to increased site coverage of CO. The TOF for methane formation (TOFCH4) increased with particle size and remained constant at higher particle sizes possibly due to combined effect from the site coverage of intermediates leading to methane (θCHx) and the pseudo-first-order rate constant (kt). The results suggest that the support can play an important role for the size dependence of the activity and selectivity of CO hydrogenation on Co catalysts.

  15. Mössbauer studies of ferrihydrite for Fischer-Tropsch catalysts

    NASA Astrophysics Data System (ADS)

    Lim, Jung Tae; Kim, Chul Sung; Chun, Dong Hyun; Park, Ji Chan

    2016-01-01

    The 6-line ferrihydrite sample for Ficher-Tropsch catalysts was prepared by using a combination of a co-precipitation technique and a spraydrying method. The crystallographic and magnetic properties of 6-line ferrihydrite sample were investigated by using x-ray diffractometer (XRD), vibrating sample magnetometer (VSM), and Mössbauer spectrometer. The XRD patterns of the ferrihydrite sample, measured at 295 K, showed 6-lines peak and its structure was found to be a single-phased hexagonal with space group of P3m1 according to JCPDS card. The temperaturedependent magnetization curves were measured under 1000 Oe between 4.2 and 300 K, and showed blocking temperature ( T B ) around 110 K. Also, Mössbauer spectra of the 6-line ferrihydrite sample were taken at various temperatures ranging from 4.2 to 295 K. At temperature below T B , the obtained spectra were analyzed as two-sextets for Fe sites, while At temperature above T B , the obtained spectra showed a doublet due to relaxation, resulting from the spin dynamic effect.

  16. Mechanistic role of water on the rate and selectivity of Fischer-Tropsch synthesis on ruthenium catalysts.

    PubMed

    Hibbitts, David D; Loveless, Brett T; Neurock, Matthew; Iglesia, Enrique

    2013-11-18

    Water increases Fischer-Tropsch synthesis (FTS) rates on Ru through H-shuttling processes. Chemisorbed hydrogen (H*) transfers its electron to the metal and protonates the O-atom of CO* to form COH*, which subsequently hydrogenates to *HCOH* in the kinetically relevant step. H2 O also increases the chain length of FTS products by mediating the H-transfer steps during reactions of alkyl groups with CO* to form longer-chain alkylidynes and OH*. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Experimental evidence of {alpha}-olefin readsorption in Fischer-Tropsch synthesis on ruthenium-supported ETS-10 titanium silicate catalysts

    SciTech Connect

    Bianchi, C.L.; Ragaini, V.

    1997-05-01

    Fischer-Tropsch synthesis seems to develop the following two consecutive paths: a primary process that involves the formation of {alpha}-olefin products and a secondary process leading to the production of branched isomers and paraffins and requiring the readsorption of primary {alpha}-olefin products. It was already shown by Iglesia et al. that such readsorption steps are of fundamental importance for Ru catalysts and that they occur due to the slow diffusive removal of {alpha}-olefins when the molecular size increases, this resulting in a long intraparticle residence time. In the present paper {alpha}-olefins readsorption was enhanced by changing the metal distribution inside the pores of a titanium silicate (ETS-10), modified by ion exchange with alkali metal ions, used as a support for Ru-based catalysts. 24 refs., 5 figs., 3 tabs.

  18. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 October 1991--31 December 1991

    SciTech Connect

    Bukur, D.B.

    1992-01-10

    The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.

  19. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 April 1990--30 June 1990

    SciTech Connect

    Bukur, D.B.

    1990-06-17

    The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.

  20. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 January 1990--31 March 1990

    SciTech Connect

    Bukur, D.B.; Patel, S.A.; Dalai, A.K.; Jayanthi, G.; Ledakowicz, S.

    1990-04-30

    The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.

  1. Technology Development for Iron Fischer-Tropsch Catalysis.

    SciTech Connect

    Davis, B.H.

    1997-12-16

    The goal of the proposed work is the development of iron-based Fischer-Tropsch catalysts that combined high activity, selectivity and life with physical robustness for slurry phase reactors that will produce either low-alpha or high-alpha products. The catalyst that is developed will be suitable for testing at the Advanced Fuels Development Facility at LaPorte, Texas or similar sized plant. Previous work by the offeror has produced a catalyst formulation that is 1.5 times as active as the `standard-catalyst` developed by German workers for slurry phase synthesis. The proposed work will optimize the catalyst composition and pretreatment operation for this low-alpha catalyst. In parallel, work will be conducted to design a high-alpha iron catalyst that is suitable for slurry phase synthesis. Studies will be conducted to define the chemical phases present at various stages of the pretreatment and synthesis stages and to define the course of these changes. The oxidation/reduction cycles that are anticipated to occur in large, commercial reactors will be studied at the laboratory scale. Catalyst performance will be determined for catalysts synthesized in this program for activity, selectivity and aging characteristics.

  2. TECHNOLOGY DEVELOPMENT FOR IRON FISCHER-TROPSCH CATALYSIS

    SciTech Connect

    Burtron H. Davis

    1998-04-01

    The goal of the proposed work is the development of iron-based Fischer-Tropsch catalysts that combined high activity, selectivity and life with physical robustness for slurry phase reactors that will produce either low-alpha or high-alpha products. The catalyst that is developed will be suitable for testing at the Advanced Fuels Development Facility at LaPorte, Texas or similar sized plant. Previous work by the offeror has produced a catalyst formulation that is 1.5 times as active as the ''standard-catalyst'' developed by German workers for slurry phase synthesis. The proposed work will optimize the catalyst composition and pretreatment operation for this low-alpha catalyst. In parallel, work will be conducted to design a high-alpha iron catalyst that is suitable for slurry phase synthesis. Studies will be conducted to define the chemical phases present at various stages of the pretreatment and synthesis stages and to define the course of these changes. The oxidation/reduction cycles that are anticipated to occur in large, commercial reactors will be studied at the laboratory scale. Catalyst performance will be determined for catalysts synthesized in this program for activity, selectivity and aging characteristics.

  3. Fischer-Tropsch Cobalt Catalyst Improvements with the Presence of TiO2, La2O3, and ZrO2 on an Alumina Support

    NASA Technical Reports Server (NTRS)

    Klettlinger, Jennifer Lindsey Suder

    2012-01-01

    The objective of this study was to evaluate the effect of titanium oxide, lanthanum oxide, and zirconium oxide on alumina supported cobalt catalysts. The hypothesis was that the presence of lanthanum oxide, titanium oxide, and zirconium oxide would reduce the interaction between cobalt and the alumina support. This was of interest because an optimized weakened interaction could lead to the most advantageous cobalt dispersion, particle size, and reducibility. The presence of these oxides on the support were investigated using a wide range of characterization techniques such as SEM, nitrogen adsorption, x-ray diffraction (XRD), temperature programmed reduction (TPR), temperature programmed reduction after reduction (TPR-AR), and hydrogen chemisorptions/pulse reoxidation. Results indicated that both La2O3 and TiO2 doped supports facilitated the reduction of cobalt oxide species in reference to pure alumina supported cobalt catalysts, however further investigation is needed to determine the effect of ZrO2 on the reduction profile. Results showed an increased corrected cluster size for all three doped supported catalysts in comparison to their reference catalysts. The increase in reduction and an increase in the cluster size led to the conclusion that the support-metal interaction weakened by the addition of TiO2 and La2O3. It is also likely that the interaction decreased upon presence of ZrO2 on the alumina, but further research is necessary. Preliminary results have indicated that the alumina-supported catalysts with titanium oxide and lanthanum oxide present are of interest because of the weakened cobalt support interaction. These catalysts showed an increased extent of reduction, therefore more metallic cobalt is present on the support. However, whether or not there is more cobalt available to participate in the Fischer-Tropsch synthesis reaction (cobalt surface atoms) depends also on the cluster size. On one hand, increasing cluster size alone tends to decrease the

  4. Heat transfer and bubble dynamics in bubble and slurry bubble columns with internals for Fischer-Tropsch synthesis of clean alternative fuels and chemicals

    NASA Astrophysics Data System (ADS)

    Kagumba, Moses Odongo O.

    Synthesis gas, a mixture of CO and H2 obtained from coal, natural gas and biomass are increasingly becoming reliable sources of clean synthetic fuels and chemicals and via Fischer-Tropsch (F-T) synthesis process. Slurry bubble column reactor is the reactor of choice for the commercialization of the F-T synthesis. Even though the slurry bubble column reactors and contactors are simple in structures, their design, scale-up, operation, and performance prediction are still challenging and not well understood due to complex interaction of phases. All the studies of heat transfer have been performed without simultaneously investigating the bubble dynamics adjacent to the heat transfer surfaces, particularly in slurry with dense internals. This dissertation focuses on enhancing the understanding of the role of local and overall gas holdup, bubble passage frequency, bubble sizes and bubble velocity on the heat transfer characteristics by means of a hybrid measurement technique comprising an advanced four-point optical probe and a fast response heat transfer probe used simultaneously, in the presence and absence of dense internals. It also seeks to advance a mechanistic approach for estimating the needed parameters for predicting the heat transfer rate in two phase and three phase systems. The results obtained suggest that the smaller diameter internals gives higher heat transfer coefficient, higher local and overall gas holdup, bubble passage frequency and specific interfacial area but smaller bubble sizes and lower axial bubble velocities. The presence of dense internals enhances the heat transfer coefficient in both the large and smaller columns, while increased column diameter increases the heat transfer coefficient, axial bubble velocity, local and overall gas holdup, bubble chord lengths and specific interfacial area. Addition of solids (glass beads) leads to increased bubble chord lengths and increase in axial bubble velocity, but a decrease in local and overall gas

  5. Process for upgrading wax from Fischer-Tropsch synthesis

    DOEpatents

    Derr, W.R. Jr.; Garwood, W.E.; Kuo, J.C.; Leib, T.M.; Nace, D.M.; Tabak, S.A.

    1987-08-04

    The waxy liquid phase of an oil suspension of Fischer-Tropsch catalyst containing dissolved wax is separated out and the wax is converted by hydrocracking, dewaxing or by catalytic cracking with a low activity catalyst to provide a highly olefinic product which may be further converted to premium quality gasoline and/or distillate fuel. 2 figs.

  6. Process for upgrading wax from Fischer-Tropsch synthesis

    DOEpatents

    Derr, Jr., W. Rodman; Garwood, William E.; Kuo, James C.; Leib, Tiberiu M.; Nace, Donald M.; Tabak, Samuel A.

    1987-01-01

    The waxy liquid phase of an oil suspension of Fischer-Tropsch catalyst containing dissolved wax is separated out and the wax is converted by hydrocracking, dewaxing or by catalytic cracking with a low activity catalyst to provide a highly olefinic product which may be further converted to premium quality gasoline and/or distillate fuel.

  7. Fischer-Tropsch slurry phase process variations to understand wax formations: Quarterly report, July 1, 1987-September 30, 1987

    SciTech Connect

    Satterfield, C.N.

    1987-01-01

    The performance of a sample of Ruhrchemie catalyst is compared in an approximate fashion to that of a PETC precipitated Fe catalyst, Mobil low wax and high wax catalysts, Sasol fixed bed catalyst and C-73 fused magnetite catalyst. Results indicate that the Ruhrchemie catalyst has about one-third the activity of the other catalysts, and is much less active for the water gas shift. It shows a double ..cap alpha.. distribution, breaking at about C/sub 7/, ..cap alpha../sub 1/ = 0.68 and ..cap alpha../sub 2/ = 0.85. C/sub 12+/ formation was comparable to that from the PETC catalyst and the Mobil low wax catalyst, higher than that from C-73 and lower than that produced by Mobil high wax catalyst and in the Sasol fixed bed reactors. The effect of adding CO/sub 2/ during synthesis on a C-73 magnetite catalyst has been studied. CO/sub 2/ forms H/sub 2/O by the reverse water gas shift and the kinetics observed can be attributed to the H/sub 2/O formation. The effects on product selectivity also seem to be mostly attributable to the H/sub 2/O formed. 6 figs., 3 tabs.

  8. Development of precipitated iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 July 1995--30 September 1995

    SciTech Connect

    Bukur, D.B.

    1995-12-20

    The following accomplishments were made on task 4. Reproducibility of Catalyst Preparation: (1) Five slurry reactor tests were completed. Three tests were conducted using catalyst C (100 Fe/3 Cu/4 K/16 SiO{sub 2}) from three different batches (runs SB-2695, SB-2145 and SA-2715), and two tests were conducted with catalyst B (100 Fe/5 Cu/6 K/24 SiO{sub 2}) from two different preparation batches (runs SA-2615 and SB-2585). Performance of catalysts from different batches (activity, selectivity and deactivation rates) was similar to that of catalysts from the original batch (synthesized during DOE Contract DE- AC22-89PC89868). Thus, another major objective of the present contract, demonstration of reproducibility of catalyst preparation procedure and performance, has been accomplished. With these tests the work on Task 4 has been successfully completed. Two fixed bed reactor tests of catalysts B and C synthesized using potassium silicate solution as the source of potassium promoter were completed during this period (Task 5. The Effect of Source of Potassium and Basic Oxide Promoter). Activity of catalysts prepared using potassium silicate as the source of potassium promotion was somewhat higher, and their methane selectivities were higher than those of the corresponding catalysts prepared by incipient wetness impregnation using KHCO{sub 3} as the source of potassium promoter. However, these differences were not large, and may have been caused by experimental artifacts (e.g. existence of local hot spots in a reactor). A slurry reactor test (SA-2405) of catalyst with nominal composition 100 Fe/5 Cu/2 Ca/24 SiO{sub 2} was completed (Task 5). In general, the catalyst activity, space-time-yield, and hydrocarbon selectivities in this run during testing at:260{degrees}C, 2.17 MPa (300 psig), 2-2.6 Nl/g-cat/h and H{sub 2}CO=0.67 were quite good, and comparable to the best results obtained in our Laboratory.

  9. Alternative Fuel Research in Fischer-Tropsch Synthesis

    NASA Technical Reports Server (NTRS)

    Surgenor, Angela D.; Klettlinger, Jennifer L.; Yen, Chia H.; Nakley, Leah M.

    2011-01-01

    NASA Glenn Research Center has recently constructed an Alternative Fuels Laboratory which is solely being used to perform Fischer-Tropsch (F-T) reactor studies, novel catalyst development and thermal stability experiments. Facility systems have demonstrated reliability and consistency for continuous and safe operations in Fischer-Tropsch synthesis. The purpose of this test facility is to conduct bench scale Fischer-Tropsch (F-T) catalyst screening experiments while focusing on reducing energy inputs, reducing CO2 emissions and increasing product yields within the F-T process. Fischer-Tropsch synthesis is considered a gas to liquid process which reacts syn-gas (a gaseous mixture of hydrogen and carbon monoxide), over the surface of a catalyst material which is then converted into liquids of various hydrocarbon chain length and product distributions1. These hydrocarbons can then be further processed into higher quality liquid fuels such as gasoline and diesel. The experiments performed in this laboratory will enable the investigation of F-T reaction kinetics to focus on newly formulated catalysts, improved process conditions and enhanced catalyst activation methods. Currently the facility has the capability of performing three simultaneous reactor screening tests, along with a fourth fixed-bed reactor used solely for cobalt catalyst activation.

  10. Fischer-Tropsch Synthesis: XANES Investigation of Hydrogen Chloride Poisoned Iron and Cobalt-Based Catalysts at the K-Edges of Cl, Fe, and Co

    SciTech Connect

    Pendyala, Venkat Ramana Rao; Jacobs, Gary; Ma, Wenping; Sparks, Dennis E.; Shafer, Wilson D.; Khalid, Syed; Xiao, Qunfeng; Hu, Yongfeng; Davis, Burtron H.

    2016-07-23

    The effect of co-fed hydrogen chloride (HCl) in syngas on the performance of iron and cobalt-based Fischer-Tropsch (FT) catalysts was investigated in our earlier studies [ACS Catal. 5 (2015) 3124-3136 and DOE final report 2011; Catal. Lett. 144 (2014) 1127-1133]. For an iron catalyst, lower HCl concentrations (< 2.0 ppmw of HCl)) in syngas did not significantly affect the activity, whereas rapid deactivation occurred at higher concentrations (~20 ppmw). With cobalt catalysts, even low concentrations of HCl (100 ppbw) caused catalyst deactivation, and the deactivation rate increased with increasing HCl concentration in the syngas. The deactivation of the catalysts is explained by the chloride being adsorbed on the catalyst surface to (1) block the active sites and/or (2) electronically modify the sites. In this study, XANES spectroscopy was employed to investigate HCl poisoning mechanism on the iron and cobalt catalysts. Cl K-edge normalized XANES results indicate that Cl is indeed present on the catalyst following HCl poisoning and exhibits a structure similar to the family of compounds MCl; two main peaks are formed, with the second peak consisting of a main peak and a higher energy shoulder. At the Co K and Fe K edges, the white line was observed to be slightly increased relative to the same catalyst under clean conditions. There is then the additional possibility that Cl adsorption may act in part to intercept electron density from the FT metallic function (e.g.,cobalt or iron carbide). If so, this would result in less back-donation and therefore hinder the scission of molecules such as CO.

  11. Fischer-Tropsch Synthesis: XANES Investigation of Hydrogen Chloride Poisoned Iron and Cobalt-Based Catalysts at the K-Edges of Cl, Fe, and Co

    DOE PAGES

    Pendyala, Venkat Ramana Rao; Jacobs, Gary; Ma, Wenping; ...

    2016-07-23

    The effect of co-fed hydrogen chloride (HCl) in syngas on the performance of iron and cobalt-based Fischer-Tropsch (FT) catalysts was investigated in our earlier studies [ACS Catal. 5 (2015) 3124-3136 and DOE final report 2011; Catal. Lett. 144 (2014) 1127-1133]. For an iron catalyst, lower HCl concentrations (< 2.0 ppmw of HCl)) in syngas did not significantly affect the activity, whereas rapid deactivation occurred at higher concentrations (~20 ppmw). With cobalt catalysts, even low concentrations of HCl (100 ppbw) caused catalyst deactivation, and the deactivation rate increased with increasing HCl concentration in the syngas. The deactivation of the catalysts ismore » explained by the chloride being adsorbed on the catalyst surface to (1) block the active sites and/or (2) electronically modify the sites. In this study, XANES spectroscopy was employed to investigate HCl poisoning mechanism on the iron and cobalt catalysts. Cl K-edge normalized XANES results indicate that Cl is indeed present on the catalyst following HCl poisoning and exhibits a structure similar to the family of compounds MCl; two main peaks are formed, with the second peak consisting of a main peak and a higher energy shoulder. At the Co K and Fe K edges, the white line was observed to be slightly increased relative to the same catalyst under clean conditions. There is then the additional possibility that Cl adsorption may act in part to intercept electron density from the FT metallic function (e.g.,cobalt or iron carbide). If so, this would result in less back-donation and therefore hinder the scission of molecules such as CO.« less

  12. Fischer-Tropsch Synthesis: XANES Investigation of Hydrogen Chloride Poisoned Iron and Cobalt-Based Catalysts at the K-Edges of Cl, Fe, and Co

    SciTech Connect

    Pendyala, Venkat Ramana Rao; Jacobs, Gary; Ma, Wenping; Sparks, Dennis E.; Shafer, Wilson D.; Khalid, Syed; Xiao, Qunfeng; Hu, Yongfeng; Davis, Burtron H.

    2016-07-23

    The effect of co-fed hydrogen chloride (HCl) in syngas on the performance of iron and cobalt-based Fischer-Tropsch (FT) catalysts was investigated in our earlier studies [ACS Catal. 5 (2015) 3124-3136 and DOE final report 2011; Catal. Lett. 144 (2014) 1127-1133]. For an iron catalyst, lower HCl concentrations (< 2.0 ppmw of HCl)) in syngas did not significantly affect the activity, whereas rapid deactivation occurred at higher concentrations (~20 ppmw). With cobalt catalysts, even low concentrations of HCl (100 ppbw) caused catalyst deactivation, and the deactivation rate increased with increasing HCl concentration in the syngas. The deactivation of the catalysts is explained by the chloride being adsorbed on the catalyst surface to (1) block the active sites and/or (2) electronically modify the sites. In this study, XANES spectroscopy was employed to investigate HCl poisoning mechanism on the iron and cobalt catalysts. Cl K-edge normalized XANES results indicate that Cl is indeed present on the catalyst following HCl poisoning and exhibits a structure similar to the family of compounds MCl; two main peaks are formed, with the second peak consisting of a main peak and a higher energy shoulder. At the Co K and Fe K edges, the white line was observed to be slightly increased relative to the same catalyst under clean conditions. There is then the additional possibility that Cl adsorption may act in part to intercept electron density from the FT metallic function (e.g.,cobalt or iron carbide). If so, this would result in less back-donation and therefore hinder the scission of molecules such as CO.

  13. Performance characterization of CNTs and γ-Al{sub 2}O{sub 3} supported cobalt catalysts in Fischer-Tropsch reaction

    SciTech Connect

    Ali, Sardar; Zabidi, Noor Asmawati Mohd; Subbarao, Duvvuri

    2014-10-24

    Catalysts were prepared via a wet impregnation method. Different physicochemical properties of the samples were revealed by transmission electron microscope (TEM), temperature programmed reduction (H{sub 2}-TPR) and carbon dioxide desorption (CO{sub 2}-desorption). Fischer-Tropsch reaction (FTS) was carried out in a fixed-bed microreactor at 220°C and 1 atm, with H{sub 2}/CO = 2v/v and space velocity, SV of 12L/g.h for 5 h. Various characterization techniques revealed that there was a stronger interaction between Co and Al{sub 2}O{sub 3} support compared to that of CNTs support. CNTs support increased the reducibility and decreased Co particle size. A significant increase in % CO conversion and FTS reaction rate was observed over CNTs support compared to that of Co/Al{sub 2}O{sub 3}. Co/CNTs resulted in higher C{sub 5+} hydrocarbons selectivity compared to that of Co/Al{sub 2}O{sub 3} catalyst. CNTs are a better support for Co compared to Al{sub 2}O{sub 3}.

  14. Impact of Contaminants Present in Coal-Biomass Derived Synthesis Gas on Water-gas Shift and Fischer-Tropsch Synthesis Catalysts

    SciTech Connect

    Alptekin, Gokhan

    2013-02-15

    Co-gasification of biomass and coal in large-scale, Integrated Gasification Combined Cycle (IGCC) plants increases the efficiency and reduces the environmental impact of making synthesis gas ("syngas") that can be used in Coal-Biomass-to-Liquids (CBTL) processes for producing transportation fuels. However, the water-gas shift (WGS) and Fischer-Tropsch synthesis (FTS) catalysts used in these processes may be poisoned by multiple contaminants found in coal-biomass derived syngas; sulfur species, trace toxic metals, halides, nitrogen species, the vapors of alkali metals and their salts (e.g., KCl and NaCl), ammonia, and phosphorous. Thus, it is essential to develop a fundamental understanding of poisoning/inhibition mechanisms before investing in the development of any costly mitigation technologies. We therefore investigated the impact of potential contaminants (H2S, NH3, HCN, AsH3, PH3, HCl, NaCl, KCl, AS3, NH4NO3, NH4OH, KNO3, HBr, HF, and HNO3) on the performance and lifetime of commercially available and generic (prepared in-house) WGS and FT catalysts.

  15. Development of precipitated iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 October 1995--31 December 1995

    SciTech Connect

    Bukur, D.B.

    1996-02-14

    Two stirred tank slurry reactor tests of catalysts with nominal compositions 100 Fe/3Cu/4 K/2 Ca/16 SiO{sub 2} (run SB-3115) and 100 Fe/5 Cu/6 K/24 SiO{sub 2} (run SA-3155) were completed under task 5, The Effect of Source of Potassium and Basic Oxide Promoter, during the reporting period. Our assessment of the effects of addition of CaO promoter to our baseline catalysts B and C and the use of potassium silicate as the source of potassium promoter is as follows: in general, the addition of CaO promoter did not result in improved performance of the baseline catalysts; the use of CaO promoter may be best suited for operation at higher reaction pressures; the baseline procedure utilizing impregnation of Fe-Cu-SiO{sub 2} precursor with aqueous solution of KHCO{sub 3} as the source of potassium promoter is the preferred method of preparation; and the procedure which utilizes aqueous K{sub 2}SiO{sub 3} solution as the source of potassium also provides satisfactory results, and may be used as an alternative. A slurry reactor test (run SB-3425) was completed during the reporting period, following the catalyst pretreatment with H{sub 2} at 250{degrees}C for 4 h (Task 6. Pretreatment Effect Research). This pretreatment resulted in higher catalyst activity than our baseline procedure (H{sub 2} at 240{degrees}C for 2 h) but also higher methane and gaseous hydrocarbon selectivities (about 10-20% higher).

  16. Sandia support for PETC Fischer-Tropsch research: Experimental characterization of slurry-phase bubble-column reactor hydrodynamics

    SciTech Connect

    Jackson, N.B.; Torczynski, J.R.; Shollenberger, K.A.; O`Hern, T.J.; Adkins, D.R.

    1996-06-01

    Sandia`s program to develop, implement, and apply diagnostics for hydrodynamic characterization of slurry bubble-column reactors (SBCRs) at industrially relevant conditions is discussed. Gas-liquid flow experiments are performed in an industrial-scale 48 cm ID stainless steel vessel. Gamma-densitometry tomography (GDT) is applied to make spatially resolved gas holdup measurements. Both water and Drakeol 10 with air sparging are examined at ambient and elevated pressures. Gas holdup increases with gas superficial velocity and pressure, and the GDT values are in good agreement with values from differential pressure measurements. Other diagnostic techniques are also discussed.

  17. Improved Sasol Fischer-Tropsch processes

    SciTech Connect

    Jager, B.

    1995-12-31

    Fischer-Tropsch (FT) processes can be used to produce either a light syncrude and light olefins or to produce heavy waxy hydrocarbons. The syncrude can be refined to environmentally friendly gasoline and diesel and the heavy hydrocarbons to specialty waxes or if hydrocracked, and/or isomerized, to produce excellent diesel, lube oils and a naphtha which is ideal feedstock for cracking. Over the last few years much better reactor systems have been developed for both high temperature FT (HTFT) and low temperature FT (LTFT). For HTFT the Sasol Advanced Synthol (SAS) reactor with solid-gas fluidization was developed. This gives very much the same product spectra as the CFB reactors, but does it much more effectively and cheaply. For LTFT, the Sasol Slurry Phase Distillate (SSPD) reactor, of the bubble column type, was developed which is a significant improvement on the tubular fixed bed (TFB) reactor used in the Arge process. The SSPD reactor can make products with the same carbon distribution as the TFB reactor with Schulz-Flory distribution alpha values 0,95 and higher. It has greater flexibility with respect to product distribution. The paper describes both reactors, and the integration of Fischer-Tropsch synthesis with coal gasification.

  18. Six-flow operations for catalyst development in Fischer-Tropsch synthesis: Bridging the gap between high-throughput experimentation and extensive product evaluation

    SciTech Connect

    Sartipi, Sina E-mail: J.Gascon@tudelft.nl; Jansma, Harrie; Bosma, Duco; Boshuizen, Bart; Makkee, Michiel; Gascon, Jorge E-mail: J.Gascon@tudelft.nl; Kapteijn, Freek

    2013-12-15

    Design and operation of a “six-flow fixed-bed microreactor” setup for Fischer-Tropsch synthesis (FTS) is described. The unit consists of feed and mixing, flow division, reaction, separation, and analysis sections. The reactor system is made of five heating blocks with individual temperature controllers, assuring an identical isothermal zone of at least 10 cm along six fixed-bed microreactor inserts (4 mm inner diameter). Such a lab-scale setup allows running six experiments in parallel, under equal feed composition, reaction temperature, and conditions of separation and analysis equipment. It permits separate collection of wax and liquid samples (from each flow line), allowing operation with high productivities of C5+ hydrocarbons. The latter is crucial for a complete understanding of FTS product compositions and will represent an advantage over high-throughput setups with more than ten flows where such instrumental considerations lead to elevated equipment volume, cost, and operation complexity. The identical performance (of the six flows) under similar reaction conditions was assured by testing a same catalyst batch, loaded in all microreactors.

  19. Fischer-Tropsch-Type Production of Organic Materials in the Solar Nebula: Studies Using Graphite Catalysts and Measuring the Trapping of Noble Gases

    NASA Technical Reports Server (NTRS)

    Nuth, Joseph A., III; Ferguson, Frank T.; Lucas, Christopher; Kimura, Yuki; Hohenberg, Charles

    2009-01-01

    The formation of abundant carbonaceous material in meteorites is a long standing problem and an important factor in the debate on the potential for the origin of life in other stellar systems. The Fischer-Tropsch-type (FTT) catalytic reduction of CO by hydrogen was once the preferred model for production of organic materials in the primitive solar nebula. We have demonstrated that many grain surfaces can catalyze both FTT and HB-type reactions, including amorphous iron and magnesium silicates, pure silica smokes as well as several minerals. Graphite is not a particularly good FTT catalyst, especially compared to iron powder or to amorphous iron silicate. However, like other silicates that we have studied, it gets better with exposure to CO. N2 and H2 over time: e.g., after formation of a macromolecular carbonaceous layer on the surfaces of the underlying gains. While amorphous iron silicates required only 1 or 2 experimental runs to achieve steady state reaction rates, graphite only achieved steady state after 6 or more experiments. We will present results showing the catalytic action of graphite grains increasing with increasing number of experiments and will also discuss the nature of the final "graphite" grains aster completion of our experiments.

  20. Simulation models and designs for advanced Fischer-Tropsch technology

    SciTech Connect

    Choi, G.N.; Kramer, S.J.; Tam, S.S.

    1995-12-31

    Process designs and economics were developed for three grass-roots indirect Fischer-Tropsch coal liquefaction facilities. A baseline and an alternate upgrading design were developed for a mine-mouth plant located in southern Illinois using Illinois No. 6 coal, and one for a mine-mouth plane located in Wyoming using Power River Basin coal. The alternate design used close-coupled ZSM-5 reactors to upgrade the vapor stream leaving the Fischer-Tropsch reactor. ASPEN process simulation models were developed for all three designs. These results have been reported previously. In this study, the ASPEN process simulation model was enhanced to improve the vapor/liquid equilibrium calculations for the products leaving the slurry bed Fischer-Tropsch reactors. This significantly improved the predictions for the alternate ZSM-5 upgrading design. Another model was developed for the Wyoming coal case using ZSM-5 upgrading of the Fischer-Tropsch reactor vapors. To date, this is the best indirect coal liquefaction case. Sensitivity studies showed that additional cost reductions are possible.

  1. Poisoning of a silica supported cobalt catalyst due to the presence of sulfur impurities in syngas during Fischer-Tropsch synthesis: Effect of chelating agent

    SciTech Connect

    Bambal, A.S.; Gardner, T.H.; Kugler, E.L.; Dadyburjor, D.B.

    2012-01-01

    Sulfur compounds that are generally found in syngas derived from coal and biomass are a poison to Fischer-Tropsch (FT) catalysts. The presence of sulfur impurities in the ppm range can limit the life of a FT catalyst to a few hours or a few days. In this study, FT synthesis was carried out in a fixed-bed reactor at 230 °C, 20 bar, and 13,500 Ncm3/h/gcat for 72 h using syngas with H2/CO = 2.0. Cobalt-based catalysts were subjected to poisoning by 10 and 50 ppm sulfur in the syngas. The performance of FT catalyst was compared in context of syngas conversion, product selectivities and yields, during the poisoning as well as post-poisoning stages. At both the impurity concentrations, the sulfur was noted to cause permanent loss in the activity, possibly by adsorbing irreversibly on the surface. The sulfur poison affects the hydrogenation and the chain-propagation ability of the catalysts, and shifts the product selectivity towards short-chain hydrocarbons with higher percentages of olefins. Additional diffusion limitations caused due to sulfur poisoning are thought to alter the product selectivity. The shifts in product selectivities suggest that the sulfur decreases the ability of the catalyst to form C-C bonds to produce longer-chain hydrocarbons. The selective blocking of sulfur is thought to affect the hydrogenation ability on the catalyst, resulting in more olefins in the product after sulfur poisoning. The sulfur poisoning on the cobalt catalyst is expected to cause an increase in the number of sites responsible for WGS or to influence the Boudouard reaction, resulting in a higher CO2 selectivity. Both the sites responsible for CO adsorptions as well as the sites for chain growth are poisoned during the poisoning. Additionally, the performance of a base-case cobalt catalyst is compared with that of catalysts modified by chelating agents (CAs). The superior performance of CA-modified catalysts during sulfur poisoning is attributed to the presence of smaller

  2. Fischer-Tropsch wax characterization and upgrading: Final report

    SciTech Connect

    Shah, P.P.; Sturtevant, G.C.; Gregor, J.H.; Humbach, M.J.; Padrta, F.G.; Steigleder, K.Z.

    1988-06-06

    The characterization and upgrading of Fischer-Tropsch wax was studied. The focus of the program was to maximize the yield of marketable transportation fuels from the Fischer-Tropsch process. The wax was characterized using gel permeation chromatography (GPC), high resolution mass spectrometry (HRMS), infrared spectroscopy (IR), gas chromatography (GC), nuclear magnetic resonance (NMR) and various other physical analyses. Hydrocracking studies conducted in a pilot plant indicate that Fischer-Tropsch wax is an excellent feedstock. A high yield of excellent quality diesel fuel was produced with satisfactory catalyst performance at relatively mild operating conditions. Correlations for predicting key diesel fuel properties were developed and checked against actual laboratory blend data. The blending study was incorporated into an economic evaluation. Finally, it is possible to take advantage of the high quality of the Fischer-Tropsch derived distillate by blending a lower value light cycle oil (produced from a refinery FCC unit) representing a high aromatic and low cetane number. The blended stream meets diesel pool specifications (up to 60 wt % LCO addition). The value added to this blending stream further enhances the upgrading complex return. 22 refs., 39 figs., 48 tabs.

  3. Sensitivity of Fischer-Tropsch Synthesis and Water-Gas Shift Catalysts to Poisons from High-Temperature High-Pressure Entrained-Flow (EF) Oxygen-Blown Gasifier Gasification of Coal/Biomass Mixtures

    SciTech Connect

    Burtron Davis; Gary Jacobs; Wenping Ma; Khalid Azzam; Dennis Sparks; Wilson Shafer

    2010-09-30

    The successful adaptation of conventional cobalt and iron-based Fischer-Tropsch synthesis catalysts for use in converting biomass-derived syngas hinges in part on understanding their susceptibility to byproducts produced during the biomass gasification process. With the possibility that oil production will peak in the near future, and due to concerns in maintaining energy security, the conversion of biomass-derived syngas and syngas derived from coal/biomass blends to Fischer-Tropsch synthesis products to liquid fuels may provide a sustainable path forward, especially considering if carbon sequestration can be successfully demonstrated. However, one current drawback is that it is unknown whether conventional catalysts based on iron and cobalt will be suitable without proper development because, while ash, sulfur compounds, traces of metals, halide compounds, and nitrogen-containing chemicals will likely be lower in concentration in syngas derived from mixtures of coal and biomass (i.e., using an entrained-flow oxygen-blown gasifier) than solely from coal, other byproducts may be present in higher concentrations. The current project examines the impact of a number of potential byproducts of concern from the gasification of biomass process, including compounds containing alkali chemicals like the chlorides of sodium and potassium. In the second year, researchers from the University of Kentucky Center for Applied Energy Research (UK-CAER) continued the project by evaluating the sensitivity of a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to a number of different compounds, including KHCO{sub 3}, NaHCO{sub 3}, HCl, HBr, HF, H{sub 2}S, NH{sub 3}, and a combination of H{sub 2}S and NH{sub 3}. Cobalt and iron-based Fischer-Tropsch synthesis (FT) catalysts were also subjected to a number of the same compounds in order to evaluate their sensitivities.

  4. Determination of the Effect of Coal/Biomass-Derived Syngas Contaminants on the Performance of Fischer-Tropsch and Water-Gas-Shift Catalysts

    SciTech Connect

    Trembly, Jason; Cooper, Matthew; Farmer, Justin; Turk, Brian; Gupta, Raghubir

    2010-12-31

    Today, nearly all liquid fuels and commodity chemicals are produced from non-renewable resources such as crude oil and natural gas. Because of increasing scrutiny of carbon dioxide (CO{sub 2}) emissions produced using traditional fossil-fuel resources, the utilization of alternative feedstocks for the production of power, hydrogen, value-added chemicals, and high-quality hydrocarbon fuels such as diesel and substitute natural gas (SNG) is critical to meeting the rapidly growing energy needs of modern society. Coal and biomass are particularly attractive as alternative feedstocks because of the abundant reserves of these resources worldwide. The strategy of co-gasification of coal/biomass (CB) mixtures to produce syngas for synthesis of Fischer-Tropsch (FT) fuels offers distinct advantages over gasification of either coal or biomass alone. Co-feeding coal with biomass offers the opportunity to exploit economies of scale that are difficult to achieve in biomass gasification, while the addition of biomass to the coal gasifier feed leverages proven coal gasification technology and allows CO{sub 2} credit benefits. Syngas generated from CB mixtures will have a unique contaminant composition because coal and biomass possess different concentrations and types of contaminants, and the final syngas composition is also strongly influenced by the gasification technology used. Syngas cleanup for gasification of CB mixtures will need to address this unique contaminant composition to support downstream processing and equipment. To investigate the impact of CB gasification on the production of transportation fuels by FT synthesis, RTI International conducted thermodynamic studies to identify trace contaminants that will react with water-gas-shift and FT catalysts and built several automated microreactor systems to investigate the effect of single components and the synergistic effects of multiple contaminants on water-gas-shift and FT catalyst performance. The contaminants

  5. Effects of Weak Surface Modification on Co/SiO2 Catalyst for Fischer-Tropsch Reaction

    PubMed Central

    Ning, Wensheng; Shen, Hehong; Jin, Yangfu; Yang, Xiazhen

    2015-01-01

    A weak surface modification is applied to Co/SiO2 catalyst by hydrothermal treatment at 180°C for 5 h. Aluminum is introduced to Co/SiO2 catalysts during the surface modification. The effects of surface modification on Co/SiO2 catalyst are studied by changing the operating sequences of surface modification and cobalt impregnation in the catalyst preparation. Surface modification before cobalt impregnation makes Co3O4 particle small and dispersed into the deep part of enlarged pore in SiO2, while surface modification after cobalt impregnation does not obviously change the particle size of Co3O4. The improved amplitude of catalytic activity is similar for the two kinds of catalysts, but they are benefited from different factors. The content of iso-hydrocarbons in the products is increased by the surface modifications. PMID:25938725

  6. Effects of Weak Surface Modification on Co/SiO2 Catalyst for Fischer-Tropsch Reaction.

    PubMed

    Ning, Wensheng; Shen, Hehong; Jin, Yangfu; Yang, Xiazhen

    2015-01-01

    A weak surface modification is applied to Co/SiO2 catalyst by hydrothermal treatment at 180°C for 5 h. Aluminum is introduced to Co/SiO2 catalysts during the surface modification. The effects of surface modification on Co/SiO2 catalyst are studied by changing the operating sequences of surface modification and cobalt impregnation in the catalyst preparation. Surface modification before cobalt impregnation makes Co3O4 particle small and dispersed into the deep part of enlarged pore in SiO2, while surface modification after cobalt impregnation does not obviously change the particle size of Co3O4. The improved amplitude of catalytic activity is similar for the two kinds of catalysts, but they are benefited from different factors. The content of iso-hydrocarbons in the products is increased by the surface modifications.

  7. Development of precipitated iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 January 1995--31 March 1995

    SciTech Connect

    Bukur, D.B.; Lang, X.; Reddy, B.

    1995-05-23

    During the reporting period we completed synthesis of about 100 g of catalyst with nominal composition 100 Fe/3 Cu/4 K/16 SiO{sub 2} (S-3416-2), and of another batch (173 g) of the same catalyst (S-3416-3). Also, we synthesized two additional batches of catalyst with nominal composition 100 Fe/5 Cu/6 K/24 SiO{sub 2}, in the amounts of 240 g (S-5624-3) and 200 g (S-5624-4). These amounts are sufficient for all planned tests with these two catalysts for the entire duration of this contract. The synthesized catalysts were characterized by atomic absorption, and BET surface area and pore size distribution measurements.

  8. Shape-selective catalysts for Fischer-Tropsch chemistry : atomic layer deposition of active catalytic metals. Activity report : January 1, 2005 - September 30, 2005.

    SciTech Connect

    Cronauer, D. C.

    2011-04-15

    Argonne National Laboratory is carrying out a research program to create, prepare, and evaluate catalysts to promote Fischer-Tropsch (FT) chemistry - specifically, the reaction of hydrogen with carbon monoxide to form long-chain hydrocarbons. In addition to needing high activity, it is desirable that the catalysts have high selectivity and stability with respect to both mechanical strength and aging properties. The broad goal is to produce diesel fraction components and avoiding excess yields of both light hydrocarbons and heavy waxes. Originally the goal was to prepare shape-selective catalysts that would limit the formation of long-chain products and yet retain the active metal sites in a protected 'cage.' Such catalysts were prepared with silica-containing fractal cages. The activity was essentially the same as that of catalysts without the cages. We are currently awaiting follow-up experiments to determine the attrition strength of these catalysts. A second experimental stage was undertaken to prepare and evaluate active FT catalysts formed by atomic-layer deposition [ALD] of active components on supported membranes and particulate supports. The concept was that of depositing active metals (i.e. ruthenium, iron or cobalt) upon membranes with well defined flow channels of small diameter and length such that the catalytic activity and product molecular weight distribution could be controlled. In order to rapidly evaluate the catalytic membranes, the ALD coating processes were performed in an 'exploratory mode' in which ALD procedures from the literature appropriate for coating flat surfaces were applied to the high surface area membranes. Consequently, the Fe and Ru loadings in the membranes were likely to be smaller than those expected for complete monolayer coverage. In addition, there was likely to be significant variation in the Fe and Ru loading among the membranes due to difficulties in nucleating these materials on the aluminum oxide surfaces. The first

  9. Sensitivity of Fischer-Tropsch Synthesis and Water-Gas Shift Catalysts to Poisons from High-Temperature High-Pressure Entrained-Flow (EF) Oxygen-Blown Gasifier Gasification of Coal/Biomass Mixtures

    SciTech Connect

    Burton Davis; Gary Jacobs; Wenping Ma; Dennis Sparks; Khalid Azzam; Janet Chakkamadathil Mohandas; Wilson Shafer; Venkat Ramana Rao Pendyala

    2011-09-30

    There has been a recent shift in interest in converting not only natural gas and coal derived syngas to Fischer-Tropsch synthesis products, but also converting biomass-derived syngas, as well as syngas derived from coal and biomass mixtures. As such, conventional catalysts based on iron and cobalt may not be suitable without proper development. This is because, while ash, sulfur compounds, traces of metals, halide compounds, and nitrogen-containing chemicals will likely be lower in concentration in syngas derived from mixtures of coal and biomass (i.e., using entrained-flow oxygen-blown gasifier gasification gasification) than solely from coal, other compounds may actually be increased. Of particular concern are compounds containing alkali chemicals like the chlorides of sodium and potassium. In the first year, University of Kentucky Center for Applied Energy Research (UK-CAER) researchers completed a number of tasks aimed at evaluating the sensitivity of cobalt and iron-based Fischer-Tropsch synthesis (FT) catalysts and a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to alkali halides. This included the preparation of large batches of 0.5%Pt-25%Co/Al{sub 2}O{sub 3} and 100Fe: 5.1Si: 3.0K: 2.0Cu (high alpha) catalysts that were split up among the four different entities participating in the overall project; the testing of the catalysts under clean FT and WGS conditions; the testing of the Fe-Cr WGS catalyst under conditions of co-feeding NaCl and KCl; and the construction and start-up of the continuously stirred tank reactors (CSTRs) for poisoning investigations. In the second and third years, researchers from the University of Kentucky Center for Applied Energy Research (UK-CAER) continued the project by evaluating the sensitivity of a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to a number of different compounds, including KHCO{sub 3}, NaHCO{sub 3}, HCl, HBr, HF, H{sub 2}S, NH{sub 3}, and a combination of H

  10. Fischer-Tropsch synthesis in supercritical fluids. Final report

    SciTech Connect

    Akgerman, A.; Bukur, D.B.

    1998-12-31

    The objective of this study was to investigate Fischer-Tropsch Synthesis (FTS) in the supercritical phase employing a commercial precipitated iron catalysts. As the supercritical fluid the authors used propane and n-hexane. The catalyst had a nominal composition of 100 Fe/5 Cu/4.2 K/25 SiO{sub 2} on mass basis and was used in a fixed bed reactor under both normal (conventional) and supercritical conditions. Experimental data were obtained at different temperatures (235 C, 250 C, and 260 C) and synthesis gas feed compositions (H{sub 2}/CO molar feed ratio of 0.67, 1.0 and 2.0) in both modes of operation under steady state conditions. The authors compared the performance of the precipitated iron catalyst in the supercritical phase, with the data obtained in gas phase (fixed bed reactor) and slurry phase (STS reactor). Comparisons were made in terms of bulk catalyst activity and various aspects of product selectivity (e.g. lumped hydrocarbon distribution and olefin content as a function of carbon number). In order to gain better understanding of the role of intraparticle mass transfer during FTS under conventional or supercritical conditions, the authors have measured diffusivities of representative hydrocarbon products in supercritical fluids, as well as their effective diffusion rates into the pores of catalyst at the reaction conditions. They constructed a Taylor dispersion apparatus to measure diffusion coefficients of hydrocarbon products of FTS in sub and supercritical ethane, propane, and hexane. In addition, they developed a tracer response technique to measure the effective diffusivities in the catalyst pores at the same conditions. Based on these results they have developed an equation for prediction of diffusion in supercritical fluids, which is based on the rough hard sphere theory.

  11. LIQUID PHASE FISCHER-TROPSCH (III IV) DEMONSTRATION IN THE LAPORTE ALTERNATIVE FUELS DEVELOPMENT UNIT. Final Topical Report. Volume I/II: Main Report. Task 1: Engineering Modifications (Fischer-Tropsch III IV Demonstration) and Task 2: AFDU Shakedown, Operations, Deactivation (Shut-Down) and Disposal (Fischer-Tropsch III IV Demonstration)

    SciTech Connect

    Bharat L. Bhatt.

    1999-06-01

    Slurry phase Fischer-Tropsch technology was successfully demonstrated in DOE's Alternative Fuels Development Unit (AFDU) at LaPorte, Texas. Earlier work at LaPorte, with iron catalysts in 1992 and 1994, had established proof-of-concept status for the slurry phase process. The third campaign (Fischer-Tropsch III), in 1996, aimed at aggressively extending the operability of the slurry reactor using a proprietary cobalt catalyst. Due to an irreversible plugging of catalyst-wax separation filters as a result of unexpected catalyst fines generation, the operations had to be terminated after seven days on-stream. Following an extensive post-run investigation by the participants, the campaign was successfully completed in March-April 1998, with an improved proprietary cobalt catalyst. These runs were sponsored by the U. S. Department of Energy (DOE), Air Products Chemicals, Inc., and Shell Synthetic Fuels, Inc. (SSFI). A productivity of approximately 140 grams (gm) of hydrocarbons (HC)/ hour (hr)-liter (lit) of expanded slurry volume was achieved at reasonable system stability during the second trial (Fischer-Tropsch IV). The productivity ranged from 110-140 at various conditions during the 18 days of operations. The catalyst/wax filters performed well throughout the demonstration, producing a clean wax product. For the most part, only one of the four filter housings was needed for catalyst/wax filtration. The filter flux appeared to exceed the design flux. A combination of use of a stronger catalyst and some innovative filtration techniques were responsible for this success. There was no sign of catalyst particle attrition and very little erosion of the slurry pump was observed, in contrast to the Fischer-Tropsch III operations. The reactor operated hydrodynamically stable with uniform temperature profile and gas hold-ups. Nuclear density and differential pressure measurements indicated somewhat higher than expected gas hold-up (45 - 50 vol%) during Fischer-Tropsch IV

  12. LIQUID PHASE FISCHER-TROPSCH (III & IV) DEMONSTRATION IN THE LAPORTE ALTERNATIVE FUELS DEVELOPMENT UNIT. Final Topical Report. Volume I/II: Main Report. Task 1: Engineering Modifications (Fischer-Tropsch III & IV Demonstration) and Task 2: AFDU Shakedown, Operations, Deactivation (Shut-Down) and Disposal (Fischer-Tropsch III & IV Demonstration).

    SciTech Connect

    Bharat L. Bhatt

    1999-06-01

    Slurry phase Fischer-Tropsch technology was successfully demonstrated in DOE's Alternative Fuels Development Unit (AFDU) at LaPorte, Texas. Earlier work at LaPorte, with iron catalysts in 1992 and 1994, had established proof-of-concept status for the slurry phase process. The third campaign (Fischer-Tropsch III), in 1996, aimed at aggressively extending the operability of the slurry reactor using a proprietary cobalt catalyst. Due to an irreversible plugging of catalyst-wax separation filters as a result of unexpected catalyst fines generation, the operations had to be terminated after seven days on-stream. Following an extensive post-run investigation by the participants, the campaign was successfully completed in March-April 1998, with an improved proprietary cobalt catalyst. These runs were sponsored by the U. S. Department of Energy (DOE), Air Products & Chemicals, Inc., and Shell Synthetic Fuels, Inc. (SSFI). A productivity of approximately 140 grams (gm) of hydrocarbons (HC)/ hour (hr)-liter (lit) of expanded slurry volume was achieved at reasonable system stability during the second trial (Fischer-Tropsch IV). The productivity ranged from 110-140 at various conditions during the 18 days of operations. The catalyst/wax filters performed well throughout the demonstration, producing a clean wax product. For the most part, only one of the four filter housings was needed for catalyst/wax filtration. The filter flux appeared to exceed the design flux. A combination of use of a stronger catalyst and some innovative filtration techniques were responsible for this success. There was no sign of catalyst particle attrition and very little erosion of the slurry pump was observed, in contrast to the Fischer-Tropsch III operations. The reactor operated hydrodynamically stable with uniform temperature profile and gas hold-ups. Nuclear density and differential pressure measurements indicated somewhat higher than expected gas hold-up (45 - 50 vol%) during Fischer-Tropsch IV

  13. Experimental reactor system for investigation of indirect liquefaction catalysts in slurry phase operation

    SciTech Connect

    Zarochak, M.F.; Pennline, H.W.; Schehl, R.R.

    1984-02-01

    A detailed description of the slurry (three-phase) reactor scheme employed at the Pittsburgh Energy Technology Center for Fischer-Tropsch synthesis is reported. Emphasis is placed on materials of construction, equipment operation, and product collection and analysis. The unit's functional limits and safety features are also provided. Operational problems and the resolving remedial action are discussed. The reactor scheme now operates such that near isothermal conditions exist over the reactor internal length. Thus, with excellent temperature control assured, reliable information for evaluation of potential catalyst candidates for slurry phase Fischer-Tropsch synthesis is possible within a wide range of operating conditions. Test results with a fused-iron catalyst suspended in a paraffinic liquid medium are given as an example.

  14. The application of inelastic neutron scattering to explore the significance of a magnetic transition in an iron based Fischer-Tropsch catalyst that is active for the hydrogenation of CO

    NASA Astrophysics Data System (ADS)

    Warringham, Robbie; McFarlane, Andrew R.; MacLaren, Donald A.; Webb, Paul B.; Tooze, Robert P.; Taylor, Jon; Ewings, Russell A.; Parker, Stewart F.; Lennon, David

    2015-11-01

    An iron based Fischer-Tropsch synthesis catalyst is evaluated using CO hydrogenation at ambient pressure as a test reaction and is characterised by a combination of inelastic neutron scattering (INS), powder X-ray diffraction, temperature-programmed oxidation, Raman scattering, and transmission electron microscopy. The INS spectrum of the as-prepared bulk iron oxide pre-catalyst (hematite, α-Fe2O3) is distinguished by a relatively intense band at 810 cm-1, which has previously been tentatively assigned as a magnon (spinon) feature. An analysis of the neutron scattering intensity of this band as a function of momentum transfer unambiguously confirms this assignment. Post-reaction, the spinon feature disappears and the INS spectrum is characterised by the presence of a hydrocarbonaceous overlayer. A role for the application of INS in magnetic characterisation of iron based FTS catalysts is briefly considered.

  15. The application of inelastic neutron scattering to explore the significance of a magnetic transition in an iron based Fischer-Tropsch catalyst that is active for the hydrogenation of CO

    SciTech Connect

    Warringham, Robbie; McFarlane, Andrew R.; Lennon, David; MacLaren, Donald A.; Webb, Paul B.; Tooze, Robert P.; Taylor, Jon; Ewings, Russell A.; Parker, Stewart F.

    2015-11-07

    An iron based Fischer-Tropsch synthesis catalyst is evaluated using CO hydrogenation at ambient pressure as a test reaction and is characterised by a combination of inelastic neutron scattering (INS), powder X-ray diffraction, temperature-programmed oxidation, Raman scattering, and transmission electron microscopy. The INS spectrum of the as-prepared bulk iron oxide pre-catalyst (hematite, α-Fe{sub 2}O{sub 3}) is distinguished by a relatively intense band at 810 cm{sup −1}, which has previously been tentatively assigned as a magnon (spinon) feature. An analysis of the neutron scattering intensity of this band as a function of momentum transfer unambiguously confirms this assignment. Post-reaction, the spinon feature disappears and the INS spectrum is characterised by the presence of a hydrocarbonaceous overlayer. A role for the application of INS in magnetic characterisation of iron based FTS catalysts is briefly considered.

  16. The application of inelastic neutron scattering to explore the significance of a magnetic transition in an iron based Fischer-Tropsch catalyst that is active for the hydrogenation of CO.

    PubMed

    Warringham, Robbie; McFarlane, Andrew R; MacLaren, Donald A; Webb, Paul B; Tooze, Robert P; Taylor, Jon; Ewings, Russell A; Parker, Stewart F; Lennon, David

    2015-11-07

    An iron based Fischer-Tropsch synthesis catalyst is evaluated using CO hydrogenation at ambient pressure as a test reaction and is characterised by a combination of inelastic neutron scattering (INS), powder X-ray diffraction, temperature-programmed oxidation, Raman scattering, and transmission electron microscopy. The INS spectrum of the as-prepared bulk iron oxide pre-catalyst (hematite, α-Fe2O3) is distinguished by a relatively intense band at 810 cm(-1), which has previously been tentatively assigned as a magnon (spinon) feature. An analysis of the neutron scattering intensity of this band as a function of momentum transfer unambiguously confirms this assignment. Post-reaction, the spinon feature disappears and the INS spectrum is characterised by the presence of a hydrocarbonaceous overlayer. A role for the application of INS in magnetic characterisation of iron based FTS catalysts is briefly considered.

  17. Sensitivity of Fischer-Tropsch Synthesis and Water-Gas Shift Catalystes to Poisons form High-Temperature High-Pressure Entrained-Flow (EF) Oxygen-Blown Gasifier Gasification of Coal/Biomass Mixtures

    SciTech Connect

    Burton Davis; Gary Jacobs; Wenping Ma; Khalid Azzam; Janet ChakkamadathilMohandas; Wilson Shafer

    2009-09-30

    There has been a recent shift in interest in converting not only natural gas and coal derived syngas to Fischer-Tropsch synthesis products, but also converting biomass-derived syngas, as well as syngas derived from coal and biomass mixtures. As such, conventional catalysts based on iron and cobalt may not be suitable without proper development. This is because, while ash, sulfur compounds, traces of metals, halide compounds, and nitrogen-containing chemicals will likely be lower in concentration in syngas derived from mixtures of coal and biomass (i.e., using entrained-flow oxygen-blown gasifier gasification gasification) than solely from coal, other compounds may actually be increased. Of particular concern are compounds containing alkali chemicals like the chlorides of sodium and potassium. In the first year, University of Kentucky Center for Applied Energy Research (UK-CAER) researchers completed a number of tasks aimed at evaluating the sensitivity of cobalt and iron-based Fischer-Tropsch synthesis (FT) catalysts and a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to alkali halides. This included the preparation of large batches of 0.5%Pt-25%Co/Al{sub 2}O{sub 3} and 100Fe: 5.1Si: 3.0K: 2.0Cu (high alpha) catalysts that were split up among the four different entities participating in the overall project; the testing of the catalysts under clean FT and WGS conditions; the testing of the Fe-Cr WGS catalyst under conditions of co-feeding NaCl and KCl; and the construction and start-up of the continuously stirred tank reactors (CSTRs) for poisoning investigations.

  18. Influence of Gas Feed Composition and Pressure on the Catalytic Conversion of CO2 to Hydrocarbons Using a Traditional Cobalt-Based Fischer-Tropsch Catalyst

    DTIC Science & Technology

    2009-06-25

    monoxide. The final product is jet and diesel fuel. Shell also has an operating gas to liquids ( GTL ) plant in Bintulu, Malaysia. The plant opened in 1993...Influence of Gas Feed Composition and Pressure on the Catalytic Conversion of CO2 to Hydrocarbons Using a Traditional Cobalt-Based Fischer-Tropsch...product distribution was measured as a function of different feed gas ratios of H2 and CO2 (3:1, 2:1, and 1:1) as well as operating pressures (ranging from

  19. Enhancing the properties of Fischer-Tropsch fuel produced from syngas over Co/SiO2 catalyst: Lubricity and Calorific Value

    NASA Astrophysics Data System (ADS)

    Doustdar, O.; Wyszynski, M. L.; Mahmoudi, H.; Tsolakis, A.

    2016-09-01

    Bio-fuel produced from renewable sources is considered the most viable alternatives for the replacement of mineral diesel fuel in compression ignition engines. There are several options for biomass derived fuels production involving chemical, biological and thermochemical processes. One of the best options is Fischer Tropsch Synthesis, which has an extensive history of gasoline and diesel production from coal and natural gas. FTS fuel could be one of the best solutions to the fuel emission due to its high quality. FTS experiments were carried out in 16 different operation conditions. Mini structured vertical downdraft fixed bed reactor was used for the FTS. Instead of Biomass gasification, a simulated N2 -rich syngas cylinder of, 33% H2 and 50% N2 was used. FT fuels products were analyzed in GCMS to find the hydrocarbon distributions of FT fuel. Calorific value and lubricity of liquid FT product were measured and compared with commercial diesel fuel. Lubricity has become an important quality, particularly for biodiesel, due to higher pressures in new diesel fuel injection (DFI) technology which demands better lubrication from the fuel and calorific value which is amount of energy released in combustion paly very important role in CI engines. Results show that prepared FT fuel has desirable properties and it complies with standard values. FT samples lubricities as measured by ASTM D6079 standard vary from 286μm (HFRR scar diameter) to 417μm which are less than limit of 520μm. Net Calorific value for FT fuels vary from 9.89 MJ/kg to 43.29 MJ/kg, with six of the samples less than EN 14213 limit of 35MJ/kg. Effect of reaction condition on FT fuel properties was investigated which illustrates that in higher pressure Fischer-Tropsch reaction condition liquid product has better properties.

  20. On the Use of Fourier Transform Infrared (FT-IR) Spectroscopy and Synthetic Calibration Spectra to Quantify Gas Concentrations in a Fischer-Tropsch Catalyst System

    NASA Technical Reports Server (NTRS)

    Ferguson, Frank T.; Johnson, Natasha M.; Nuth, Joseph A., III

    2015-01-01

    One possible origin of prebiotic organic material is that these compounds were formed via Fischer-Tropsch-type (FTT) reactions of carbon monoxide and hydrogen on silicate and oxide grains in the warm, inner-solar nebula. To investigate this possibility, an experimental system has been built in which the catalytic efficiency of different grain-analog materials can be tested. During such runs, the gas phase above these grain analogs is sampled using Fourier transform infrared (FT-IR) spectroscopy. To provide quantitative estimates of the concentration of these gases, a technique in which high-resolution spectra of the gases are calculated using the high-resolution transmission molecular absorption (HITRAN) database is used. Next, these spectra are processed via a method that mimics the processes giving rise to the instrumental line shape of the FT-IR spectrometer, including apodization, self-apodization, and broadening due to the finite resolution. The result is a very close match between the measured and computed spectra. This technique was tested using four major gases found in the FTT reactions: carbon monoxide, methane, carbon dioxide, and water. For the ranges typical of the FTT reactions, the carbon monoxide results were found to be accurate to within 5% and the remaining gases accurate to within 10%. These spectra can then be used to generate synthetic calibration data, allowing the rapid computation of the gas concentrations in the FTT experiments.

  1. Mo-Fe catalysts supported on activated carbon for synthesis of liquid fuels by the Fischer-Tropsch process: effect of Mo addition on reducibility, activity, and hydrocarbon selectivity

    SciTech Connect

    Wenping Ma; Edwin L. Kugler; James Wright; Dady B. Dadyburjor

    2006-12-15

    The effects of Mo loading (0-12 wt %) on the properties of activated-carbon- (AC-) supported Fe-Cu-K catalysts and their performance for Fischer-Tropsch synthesis are studied. Physicochemical properties studied include particle size, reducibility, and dispersion, and catalytic properties include activity, selectivity, and stability. Catalysts were characterized by N{sub 2} adsorption, energy-dispersive spectroscopy, X-ray diffraction (XRD), H{sub 2} temperature-programmed reduction (TPR), and CO chemisorption. Catalyst performance was studied at 310-320{sup o}C, 2.2 MPa, 3 Nl/g-cat/h, and H{sub 2}/CO = 0.9. Reaction results in a fixed-bed reactor show that addition of 6% Mo into the Fe-Cu-K/AC catalyst improves catalyst stability without sacrificing activity, but activity is suppressed dramatically on a 12% Mo-loaded catalyst. Detectable hydrocarbons of C{sub 1} to C{sub 34} are produced on the Fe-Cu-K/AC catalysts with or without Mo. However, the addition of Mo results in the production of more CH{sub 4} and less C{sub 5+} hydrocarbons. The Mo promoter greatly enhances secondary reactions of olefins, leading to a large amount of internal olefins (i.e., other than 1-olefins) in the product. TPR shows that a strong interaction between Fe and Mo oxides is present, and the extent of reduction of Fe is suppressed after addition of Mo to the Fe-Cu-K catalyst. CO-chemisorption and XRD studies show increased iron dispersion and decreased particle size of the iron carbide and iron oxide after the addition of Mo. Segregation of iron active sites, thereby preventing them from agglomerating, and a larger number of active sites on the 6% Mo catalyst are possible reasons for the improved stability and higher activity of Mo-promoted catalysts. 54 refs., 5 figs., 6 tabs.

  2. Fischer-Tropsch synthesis in supercritical reaction media

    SciTech Connect

    Subramaniam, B.

    1995-05-01

    The goal of the proposed research is to develop novel reactor operating strategies for the catalytic conversion of syngas to transportation grade fuels and oxygenates using near-critical (nc) fluids as reaction media. This will be achieved through systematic investigations aimed at a better fundamental understanding of the physical and chemical rate processes underlying catalytic syngas conversion in nc reaction media. Syngas conversion to fuels and fuel additives on Fe catalysts (Fischer-Tropsch synthesis) was investigated. Specific objectives are to investigate the effects of various nc media, their flow rates and operating pressure on syngas conversion, reactor temperature profiles, product selectivity and catalyst activity in trickle-bed reactors. Solvents that exhibit gas to liquid-like densities with relatively moderate pressure changes (from 25 to 60 bars) at typical syngas conversion temperatures (in the 220-280{degree}C range) will be chosen as reaction media.

  3. Fischer-Tropsch synthesis: study of the promotion of Pt on the reduction property of Co/Al2O3 catalysts by in situ EXAFS of Co K and Pt LIII edges and XPS.

    PubMed

    Jacobs, Gary; Chaney, John A; Patterson, Patricia M; Das, Tapan K; Maillot, Julie C; Davis, Burtron H

    2004-09-01

    The addition of platinum metal to cobalt/alumina-based Fischer-Tropsch synthesis (FTS) catalysts increases both the reduction rate and, consequently, the density of active cobalt sites. Platinum also lowers the temperature of the two-step conversion of cobalt oxide to cobalt metal observed in temperature programmed reduction (TPR) as Co3O4 to CoO and CoO to Co0. The interaction of the alumina support with cobalt oxide ultimately determines the active site density of the catalyst surface. This interaction can be controlled by varying the cobalt loading and dispersion, selecting supports with differing surface areas or pore sizes, or changing the noble metal promoter. However, the active site density is observed to depend primarily on the cluster size and extent of reduction, and there is a direct relationship between site density and FTS rate. In this work, in situ extended X-ray absorption fine structure (EXAFS) at the LIII edge of Pt was used to show that isolated Pt atoms interact with supported cobalt clusters without forming observable Pt--Pt bonds. K-edge EXAFS was also used to verify that the cobalt cluster size increases slightly for those systems with Pt promotion. X-ray absorption near-edge spectroscopy (XANES) was used to examine the remaining cobalt clusters after the first stage of TPR, and it revealed that the species were almost entirely cobalt (II) oxide. After the second stage of TPR to form cobalt metal, a residual oxide persists in the sample, and this oxide has been identified as cobalt (II) aluminate using X-ray photoelectron spectroscopy (XPS). Sequential in situ reduction of promoted and unpromoted systems was also monitored through XPS, and Pt was seen to increase the extent of cobalt reduction by a factor of two.

  4. Silicon carbide coated with TiO2 with enhanced cobalt active phase dispersion for Fischer-Tropsch synthesis.

    PubMed

    Liu, Yuefeng; Florea, Ileana; Ersen, Ovidiu; Pham-Huu, Cuong; Meny, Christian

    2015-01-04

    The introduction of a thin layer of TiO2 on β-SiC allows a significant improvement of the cobalt dispersion. This catalyst exhibits an excellent and stable catalytic activity for the Fischer-Tropsch synthesis (FTS) with high C5+ selectivity, which contributes to the development of a new active catalyst family in the gas-to-liquid process.

  5. New developments in cobalt-based Fischer-Tropsch catalysis and processes

    SciTech Connect

    Singleton, A.H.; Davis, B.E.; Oukaci, R.

    1997-12-31

    The Williams Companies, Inc. of Tulsa, Oklahoma, has announced a breakthrough in gas-to-liquids (GTL) technology that revolutionizes the production of transportation fuels from natural gas. Building on its twenty years of research in Fischer-Tropsch (F-T) conversion technology, Williams has developed a new process that significantly outperforms existing GTL technologies for large-scale (ca. 50,000 BPSD) applications and advances the state-of the-art of converting natural gas into high quality liquid transportation fuels. By employing a new generation of cobalt-based catalysts, Williams` GasCat{sup SM} F-T process achieves high productivity, resulting in superior catalytic reactor performance compared to existing F-T techniques. The GasCat process also reduces capital requirements and operating costs by employing advanced slurry bubble column reactor (SBCR) technology. Although the process is applicable to coal derived synthesis gas, GasCat has enormous implications for large remote gas reserves worldwide, due to the limited options previously available for exploiting the potential of such reservoirs. While the paper presents the details and significance of this new development as it relates to natural gas, it obviously has similar significance to the indirect liquefaction of coal.

  6. Public health hazards of Lurgi/Fischer-Tropsch coal liquefaction

    SciTech Connect

    Gasper, J.R.; Rosenberg, S.E.

    1981-01-01

    This analysis identifies the public hazards of wastes from Lurgi/Fischer-Tropsch coal liquefaction. Because data on dose-response and synergism are not available for many of the waste chemicals from this process, we evaluated hazards with a relative risk approach. This approach employs two measures of hazards. First, body burdens that result from exposure to Lurgi/Fischer-Tropsch wastes are compared to body burdens from other sources of the same chemicals. Second ambient concentrations of pollutants from Lurgi/Fischer-Tropsch operations are projected and compared to various air and water quality standards.

  7. Attrition resistant bulk iron catalysts and processes for preparing and using same

    DOEpatents

    Jothimurugesan, Kandaswamy; Goodwin, Jr., James G.; Gangwal, Santosh K.

    2007-08-21

    An attrition resistant precipitated bulk iron catalyst is prepared from iron oxide precursor and a binder by spray drying. The catalysts are preferably used in carbon monoxide hydrogenation processes such as Fischer-Tropsch synthesis. These catalysts are suitable for use in fluidized-bed reactors, transport reactors and, especially, slurry bubble column reactors.

  8. Fischer Tropsch synthesis in supercritical fluids. Quarterly technical progress report, January 1, 1994--March 31, 1994

    SciTech Connect

    Akgerman, A.; Bukur, D.B.

    1994-06-01

    We have successfully completed our first Fischer-Tropsch synthesis test with propane as the supercritical fluid. The catalyst activity and hydrocarbon product distribution under the SFT conditions were similar to those obtained during the normal Fischer-Tropsch synthesis, however, the use of supercritical fluid resulted in higher selectivity of the primary products. The use of a new trap with larger inside surface area, improved the collection of liquid products and thus enabling us to achieve better atomic and overall mass balance closures. This has also improved results from on-line GC analysis. However, further improvement are needed to achieve more stable and reproducible gas phase analysis, including the capability of the on-line analysis of the feed gas (mixture of hydrogen, carbon monoxide and propane).

  9. Segregation of Fischer-Tropsch reactants on cobalt nanoparticle surfaces.

    PubMed

    Lewis, E A; Le, D; Jewell, A D; Murphy, C J; Rahman, T S; Sykes, E C H

    2014-06-21

    Using scanning tunnelling microscopy, we have visualized the segregation of carbon monoxide and hydrogen, the two reactants in Fischer-Tropsch synthesis, on cobalt nanoparticles at catalytically relevant coverages. Density functional theory was used to interrogate the relevant energetics.

  10. Moessbauer spectroscopy studies of iron-catalysts used in Fischer-Tropsch (FT) processes. Quarterly technical progress report, January--March, 1994

    SciTech Connect

    Huffman, G.P.; Rao, K.R.P.M.

    1994-12-31

    The objective of this project is to carry out a Moessbauer spectroscopy study of Iron-based catalysts to identify iron phases present and correlate with water gas shift and FT activities. A total of 15 catalysts were evaluated so far. Results are presented on the amounts in each catalyst of the following phases: superparamagnetic phase, hematite ({alpha}-Fe{sub 2}O{sub 3}), magnetite (Fe{sub 3}O{sub 4}), Chi-carbide phase ({chi}-Fe{sub 5}C{sub 2}), and an epsilon-carbide phase ({var_epsilon}-Fe{sub 2.2}C).

  11. Size dependent stability of cobalt nanoparticles on silica under high conversion Fischer-Tropsch environment.

    PubMed

    Wolf, Moritz; Kotzé, Hendrik; Fischer, Nico; Claeys, Michael

    2017-02-15

    Highly monodisperse cobalt crystallites, supported on Stöber silica spheres, as model catalysts for the Fischer-Tropsch synthesis were exposed to simulated high conversion environments in the presence and absence of CO utilising an in house developed in situ magnetometer. The catalyst comprising the smallest crystallites in the metallic state (average diameter of 3.2 nm) experienced pronounced oxidation whilst the ratio of H2O to H2 was increased stepwise to simulate CO conversions from 26% up to complete conversion. Direct exposure of this freshly reduced catalyst to a high conversion Fischer-Tropsch environment resulted in almost spontaneous oxidation of 40% of the metallic cobalt. In contrast, a model catalyst with cobalt crystallites of 5.3 nm only oxidised to a small extent even when exposed to a simulated conversion of over 99%. The largest cobalt crystallites were rather stable and only experienced measurable oxidation when subjected to H2O in the absence of H2. This size dependency of the stability is in qualitative accordance with reported thermodynamic calculations. However, the cobalt crystallites showed an unexpected low susceptibility to oxidation, i.e. only relatively high ratios of H2O to H2 partial pressure caused oxidation. Similar experiments in the presence of CO revealed the significance of the actual Fischer-Tropsch synthesis on the metallic surface as the dissociation of CO, an elementary step in the Fischer-Tropsch mechanism, was shown to be a prerequisite for oxidation. Direct oxidation of cobalt to CoO by H2O seems to be kinetically hindered. Thus, H2O may only be capable of indirect oxidation, i.e. high concentrations prevent the removal of adsorbed oxygen species on the cobalt surface leading to oxidation. However, a spontaneous direct oxidation of cobalt at the interface between the support and the crystallites by H2O forming presumably cobalt silicate type species was observed in the presence and absence of CO. The formation of these

  12. Fischer-Tropsch synthesis in supercritical reaction media

    SciTech Connect

    Subramaniam, B.

    1992-10-01

    The goal of this research is to thoroughly investigate the feasibility of using supercritical fluid (SCF) solvent medium for carrying out Fischer-Tropsch (FT) synthesis. Research will address the systematic experimental investigations of FT synthesis over supported Fe and Co catalysts in a CSTR and in a fixed-bed reactor at typical synthesis temperatures (240-260[degrees]C). The SCF medium to be employed is n-Hexane (P[sub c] = 29.7 bar; [Tc] = 233.7[degrees]C), while n-Hexadecane will be employed as the liquid reaction medium. Overall conversion, product distribution and catalyst deactivation will be measured in each case for various feed H[sub 2]/CO ratios ranging from 0.5 to 2. Product analyses will be carried out using GC/TCD, GC/FID and GC/MS systems. The fresh and used catalysts will be characterized with respect to active metal dispersion, surface area and pore size distribution.

  13. A new hydrocarbon material based on seabuckthorn ( Hippophae rhamnoides) sawdust: A structural promoter of cobalt catalyst for Fischer-Tropsch synthesis

    NASA Astrophysics Data System (ADS)

    Pankina, G. V.; Chernavskii, P. A.; Lunin, V. V.

    2016-09-01

    Aspects of the physicochemical properties of a hydrocarbon material based on seabuckthorn ( Hippophae rhamnoides) sawdust are studied. The use of a hydrocarbon material based on sea buckthorn sawdust as a structural promoter of Co/CHip cobalt catalyst in the reaction of CO hydrogenation is shown to require an additional cycling stage in the mode of reduction and oxidation. The resulting mean size of the Co particles is found to be 18-19 nm and is considered acceptable for the synthesis of C5+ liquid hydrocarbons.

  14. Intensified Fischer-Tropsch Synthesis Process with Microchannel Catalytic Reactors

    SciTech Connect

    Cao, Chunshe; Hu, Jianli; Li, Shari; Wilcox, Wayne A.; Wang, Yong

    2009-02-28

    A microchannel catalytic reactor with improved heat and mass transport has been used for Fischer-Tropsch synthesis to produce fuels and chemicals. This type of novel reactor takes advantages of highly active and selective catalysts with increased site density so that the FT synthesis process can be intensified. It was demonstrated that this microchannel reactor based process can be carried out at gas hourly space velocity (GHSV) as high as 60,000 hr-1 to achieve greater than 60% of one-pass CO conversion while maintaining low methane selectivity (<10%) and high chain growth probability(>0.9). Such superior FT synthesis performance has not ever been reported in the prior open literatures. The overall productivity to heavy hydrocarbons has been significantly improved over the conventional reactor technology. In this study, performance data were obtained in a wide range of pressure (10atm-35atm) and hydrogen to carbon monoxide ratio (1-2.5). The catalytic system was characterized by BET, scanning electron microcopy (SEM), transmission electron microcopy(TEM), and H2 chemisorption. A three dimensional pseudo-homogeneous model were used to simulate temperature profiles in the exothermic reaction system in order to optimize the reactor design and intensify the synthesis process. Intraparticle non-isothermal characteristics are also analyzed for the FT synthesis catalyst.

  15. Study of Fischer-Tropsch model compounds reacting over ZSM-5. [MS Thesis

    SciTech Connect

    Riley, M.G.

    1984-08-01

    The decomposition of three Fischer-Tropsch model compounds (1-decanol, decanal, and n-heptane) over ZSM-5 catalysts ion exchanged with nickel, zinc, and hydrogen was studied. The mechanisms of decomposition and the reaction kinetics of the model compounds were investigated as well as how exchanging the ZSM-5 with different cations affected the mechanisms, kinetics, and product distribution. The mechanism for 1-decanol decomposition was found to be formation of di-n-decyl ether, which then dehydrated to form 1-decene. Decanal was seen to decompose by three different mecanisms: Aldol condensation, cleavage of CO to form n-nonane, and reduction to 1-decanol. Heptane was seen to follow classical carbonium ion chemistry. First order rate constants and activation energies were calculated for n-heptane/Ni-ZSM-5, 1-decanol/Ni-ZSM-5, 1-decanol/H-ZSM-5, decanal/Ni-ZSM-5, and decanal/H-ZSM-5. The activation energies for decomposition were found to be 21 +- 4 Kcal/gmole for 1-decanol to 1-decene; 32 +- 3 Kcal/gmole for n-heptane; and 15 +- 3 Kcal/gmole on Ni-ZSM-5 and 21 +- 1 Kcal/gmole on H-ZSM-5 for decanal decomposing to n-nonane and CO. H-ZSM-5 was determined to be the most active catalyst of the three tested for decomposition of oxygenates. N-ZSM-5 was the most effective catalyst in the cracking of n-heptane. Due to its superior ability to decompose oxygenates, H-ZSM-5 appears to be the best choice for a Fischer-Tropsch liquid up-grading catalyst. For Fischer-Tropsch liquids with high linear alkane contents a small amount of nickel or other dehydrogenation catalyst added to the H-ZSM-5 would probably prove beneficial. 26 references, 12 figures, 8 tables.

  16. Carbon Isotope Effects in the Fischer-Tropsch Synthesis

    NASA Astrophysics Data System (ADS)

    Taran, Y.; Kliger, G.; Sevastyanov, V.

    2006-05-01

    Carbon isotopic composition was measured in products of the Fischer-Tropsch synthesis in flow reactor on the modified by clays Fe-catalyst at 280-300C and 30 atm. The initial gas mixture (synthesis-gas, SG) consisted of 50 vol% of N2, 20% of CO and 30% of H2. Using the GS-MS technique we analyzed 13C/12C in CO, CO2, CH4, higher hydrocarbons until C4 and the oil fraction in the reaction products. Two catalysts with different modification were used: with high and low yield of olefins. Three of 70-hours runs for each catalyst were realized. Five gas samples were taken during each run: 10, 20, 30, 50 and 70 hours and one cumulative oil sample after each run. The 13C/12C distribution vs carbon number is time-dependent for the olefin-rich products. For the olefin-poor runs the stationary state is characterized by depletion in 13C of heavier than CH4 hydrocarbons, thus, showing the "synthetic" pattern, like in DesMarais et al. (1982) experiments or in Murchison meteorite. However, the olefin-rich runs demonstrate these patterns only in the non-stationary, initial (10 h, 20 h) time range. The steady-state (50-70h) distribution (high and stable conversion of CO) for olefin-rich runs shows almost no fractionation between CH4 and higher hydrocarbons. The concentration distribution of light hydrocarbons in our experiments was similar to that obtained by Hu et al. (1998), but with much higher conversion of CO (>95%).

  17. Closed system Fischer-Tropsch synthesis over meteoritic iron, iron ore and nickel-iron alloy. [deuterium-carbon monoxide reaction catalysis

    NASA Technical Reports Server (NTRS)

    Nooner, D. W.; Gibert, J. M.; Gelpi, E.; Oro, J.

    1976-01-01

    Experiments were performed in which meteoritic iron, iron ore and nickel-iron alloy were used to catalyze (in Fischer-Tropsch synthesis) the reaction of deuterium and carbon monoxide in a closed vessel. Normal alkanes and alkenes and their monomethyl substituted isomers and aromatic hydrocarbons were synthesized. Iron oxide and oxidized-reduced Canyon Diablo used as Fischer-Tropsch catalysts were found to produce aromatic hydrocarbons in distributions having many of the features of those observed in carbonaceous chondrites, but only at temperatures and reaction times well above 300 C and 6-8 h.

  18. Closed system Fischer-Tropsch synthesis over meteoritic iron, iron ore and nickel-iron alloy. [deuterium-carbon monoxide reaction catalysis

    NASA Technical Reports Server (NTRS)

    Nooner, D. W.; Gibert, J. M.; Gelpi, E.; Oro, J.

    1976-01-01

    Experiments were performed in which meteoritic iron, iron ore and nickel-iron alloy were used to catalyze (in Fischer-Tropsch synthesis) the reaction of deuterium and carbon monoxide in a closed vessel. Normal alkanes and alkenes and their monomethyl substituted isomers and aromatic hydrocarbons were synthesized. Iron oxide and oxidized-reduced Canyon Diablo used as Fischer-Tropsch catalysts were found to produce aromatic hydrocarbons in distributions having many of the features of those observed in carbonaceous chondrites, but only at temperatures and reaction times well above 300 C and 6-8 h.

  19. Subtask 3.4 - Fischer - Tropsch Fuels Development

    SciTech Connect

    Strege, Joshua; Snyder, Anthony; Laumb, Jason; Stanislowski, Joshua; Swanson, Michael

    2012-05-01

    Under Subtask 3.4, the Energy & Environmental Research Center (EERC) examined the opportunities and challenges facing FischerTropsch (FT) technology in the United States today. Work was completed in two distinct budget periods (BPs). In BP1, the EERC examined the technical feasibility of using modern warm-gas cleanup techniques for FT synthesis. FT synthesis is typically done using more expensive and complex cold-gas sweetening. Warm-gas cleanup could greatly reduce capital and operating costs, making FT synthesis more attractive for domestic fuel production. Syngas was generated from a variety of coal and biomass types; cleaned of sulfur, moisture, and condensables; and then passed over a pilot-scale FT catalyst bed. Laboratory and modeling work done in support of the pilot-scale effort suggested that the catalyst was performing suboptimally with warm-gas cleanup. Long-term trends showed that the catalyst was also quickly deactivating. In BP3, the EERC compared FT catalyst results using warm-gas cleanup to results using cold-gas sweetening. A gas-sweetening absorption system (GSAS) was designed, modeled, and constructed to sweeten syngas between the gasifier and the pilot-scale FT reactor. Results verified that the catalyst performed much better with gas sweetening than it had with warm-gas cleanup. The catalyst also showed no signs of rapid deactivation when the GSAS was running. Laboratory tests in support of this effort verified that the catalyst had deactivated quickly in BP1 because of exposure to syngas, not because of any design flaw with the pilot-scale FT reactor itself. Based on these results, the EERC concludes that the two biggest issues with using syngas treated with warm-gas cleanup for FT synthesis are high concentrations of CO{sub 2} and volatile organic matter. Other catalysts tested by the EERC may be more tolerant of CO{sub 2}, but volatile matter removal is critical to ensuring long-term FT catalyst operation. This subtask was funded through

  20. An Ab Initio Approach Towards Engineering Fischer-Tropsch Surface Chemistry

    SciTech Connect

    Matthew Neurock; David A. Walthall

    2006-05-07

    One of the greatest societal challenges over the next decade is the production of cheap, renewable energy for the 10 billion people that inhabit the earth. This will require the development of various different energy sources potentially including fuels derived from methane, coal, and biomass and alternatives sources such as solar, wind and nuclear energy. One approach will be to synthesize gasoline and other fuels from simpler hydrocarbons such as CO derived from methane or other U.S. based sources such as coal. Syngas (CO and H{sub 2}) can be readily converted into higher molecular weight hydrocarbons through Fischer-Tropsch synthesis. Fischer-Tropsch synthesis involves the initiation or activation of CO and H{sub 2} bonds, the subsequent propagation steps including hydrogenation and carbon-carbon coupling, followed by chain termination reactions. Commercially viable catalysts include supported Co and Co-alloys. Over the first two years of this project we have used ab initio methods to determine the adsorption energies for all reactants, intermediates, and products along with the overall reaction energies and their corresponding activation barriers over the Co(0001) surface. Over the third year of the project we developed and advanced an ab initio-based kinetic Monte Carlo simulation code to simulate Fischer Tropsch synthesis. This report details our work over the last year which has focused on the derivation of kinetic parameters for the elementary steps involved in FT synthesis from ab initio density functional theoretical calculations and the application of the kinetic Monte Carlo algorithm to simulate the initial rates of reaction for FT over the ideal Co(0001) surface. The results from our simulations over Co(0001) indicate the importance of stepped surfaces for the activation of adsorbed CO. In addition, they demonstrate that the dominant CH{sub x}* surface intermediate under steady state conditions is CH*. This strongly suggests that hydrocarbon coupling

  1. Effect of process conditions on olefin selectivity during conventional and supercritical Fischer-Tropsch synthesis

    SciTech Connect

    Bukur, D.B.; Lang, X.; Akgerman, A.; Feng, Z.

    1997-07-01

    A precipitated iron catalyst (100 Fe/5 Cu/4.2 K/25 SiO{sub 2} on mass basis) was tested in a fixed-bed reactor under a variety of process conditions during conventional Fischer-Tropsch synthesis (FTS) and supercritical Fischer-Tropsch synthesis (SFTS). In both modes of operation it was found that: total olefin content decreases whereas 2-olefin content increases with either increase in conversion or H{sub 2}/CO molar feed ratio. Total olefin and 2-olefin selectivities were essentially independent of reaction temperature. The effect of conversion was more pronounced during conventional FTS. Comparison of olefin selectivities in the two modes of operation reveals that total olefin content is greater while the 2-olefin content is smaller during SFTS. Also, both the decrease in total olefin content and the increase in 2-olefin content with increase in carbon number (i.e., molecular weight of hydrocarbon products) was significantly less pronounced during SFTS in comparison to the conventional FTS. The obtained results suggest that 1-olefins, and to a smaller extent n-paraffins, are the primary products of FTS. Secondary reactions (isomerization, hydrogenation, and readsorption) of high molecular weight {alpha}-olefins occur to a smaller extent during SFTS, due to higher diffusivities and desorption rates of {alpha}-olefins in the supercritical propane than in the liquid-filled catalyst pores (conventional FTS).

  2. Monetization of Nigeria coal by conversion to hydrocarbon fuels through Fischer-Tropsch process

    SciTech Connect

    Oguejiofor, G.C.

    2008-07-01

    Given the instability of crude oil prices and the disruptions in crude oil supply chains, this article offers a complementing investment proposal through diversification of Nigeria's energy source and dependence. Therefore, the following issues were examined and reported: A comparative survey of coal and hydrocarbon reserve bases in Nigeria was undertaken and presented. An excursion into the economic, environmental, and technological justifications for the proposed diversification and roll-back to coal-based resource was also undertaken and presented. The technology available for coal beneficiation for environmental pollution control was reviewed and reported. The Fischer-Tropsch synthesis and its advances into Sasol's slurry phase distillate process were reviewed. Specifically, the adoption of Sasol's advanced synthol process and the slurry phase distillate process were recommended as ways of processing the products of coal gasification. The article concludes by discussing all the above-mentioned issues with regard to value addition as a means of wealth creation and investment.

  3. SLURRY PHASE IRON CATALYSTS FOR INDIRECT COAL LIQUEFACTION

    SciTech Connect

    Abhaya K. Datye

    1998-11-19

    This report describes research conducted to support the DOE program in indirect coal liquefaction. Specifically, they have studied the attrition behavior of iron Fischer-Tropsch catalysts, their interaction with the silica binder and the evolution of iron phases in a synthesis gas conversion process. The results provide significant insight into factors that should be considered in the design of catalysts for converting coal based syngas into liquid fuels.

  4. Slurry Phase Iron Catalysts for Indirect Coal Liquefaction

    SciTech Connect

    Abhaya K. Datye

    1998-09-10

    This report describes research conducted to support the DOE program in indirect coal liquefaction. Specifically, we have studied the attrition behavior of Iron Fischer-Tropsch catalysts, their interaction with the silica binder and the evolution of iron phases in a synthesis gas conversion process. The results provide significant insight into factors that should be considered in the design of catalysts for the conversion of coal-derived synthesis gas into liquid fuels.

  5. 40 CFR 721.10103 - Naphtha (Fischer-Tropsch), C4-11-alkane, branched and linear.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Naphtha (Fischer-Tropsch), C4-11... Significant New Uses for Specific Chemical Substances § 721.10103 Naphtha (Fischer-Tropsch), C4-11-alkane... substance identified as naphtha (fischer-tropsch), C4-11-alkane, branched and linear (PMN P-04-235; CAS...

  6. 40 CFR 721.10178 - Distillates (Fischer-Tropsch), hydroisomerized middle, C10-13-branched alkane fraction.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Distillates (Fischer-Tropsch... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10178 Distillates (Fischer-Tropsch... to reporting. (1) The chemical substance identified as distillates (Fischer-Tropsch),...

  7. 40 CFR 721.10103 - Naphtha (Fischer-Tropsch), C4-11-alkane, branched and linear.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Naphtha (Fischer-Tropsch), C4-11... Significant New Uses for Specific Chemical Substances § 721.10103 Naphtha (Fischer-Tropsch), C4-11-alkane... substance identified as naphtha (fischer-tropsch), C4-11-alkane, branched and linear (PMN P-04-235; CAS No...

  8. Slurry Phase Iron Catalysts for Indirect Coal LIquefaction.

    SciTech Connect

    Datye, A.K.

    1997-08-08

    This report covers the fourth six month period of this three year grant under the University Coal Research program. During this period, we have begun the synthesis of precipitated catalysts using a bench-top spray dryer. The influence of binders on particle strength was also studied using the ultrasonic fragmentation approach to derive particle breaking stress. A similar approach was used to derive particle strength of catalysts obtained from Mr. Robert Gormley at FETC. Over the next six month period, this work will be continued while the catalysts prepared here will be examined by TPR to determine reducibility and the extent of adverse iron-silica interactions. A fundamental study of Fe/silica interactions has been performed using temperature programmed reaction and TEM to provide understanding of how the silica binders influence the activity of Fe catalysts. To understand differences in the reducibility of the iron phase caused by silica, we have set up a temperature programmed reduction facility. TPR in H, as well as in CO was performed of Fe/ SiO, catalysts prepared by impregnation as well as by precipitation. What is unique about these studies is that high resolution TEM was performed on samples removed from the reactor at various stages of reduction. This helps provide direct evidence for the phase changes that are detected by TPR. We have continued the analysis of catalysts received from slurry reactor runs at Texas A&M university (TAMU) and the University of Kentucky Center for Applied Energy Research (CAER) by x-ray diffraction. The purpose of the XRD analysis was to determine the phase composition of catalysts derived from a slurry reaction run using Fe Fischer-Tropsch catalysts. We had previously described how catalyst removed in the hot wax may oxidize to magnetite if the wax is air-exposed. We have now received catalysts from CAER that were removed under a protective inert blanket, and we are in the process of analyzing them, but preliminary work

  9. Trapping Planetary Noble Gases During the Fischer-Tropsch-Type Synthesis of Organic Materials

    NASA Technical Reports Server (NTRS)

    Nuth, Joseph A.; Johnson, N. M.; Meshik, A.

    2010-01-01

    When hydrogen, nitrogen and CO arc exposed to amorphous iron silicate surfaces at temperatures between 500 - 900K, a carbonaceous coating forms via Fischer-Tropsch type reactions!, Under normal circumstances such a catalytic coating would impede or stop further reaction. However, we find that this coating is a better catalyst than the amorphous iron silicates that initiate these rcactions:u . The formation of a self-perpetuating catalytic coating on grain surfaces could explain the rich deposits of macromolecular carbon found in primitive meteorites and would imply that protostellar nebulae should be rich in organic materiaL Many more experiments are needed to understand this chemical system and its application to protostellar nebulae.

  10. Platinum-Modulated Cobalt Nanocatalysts for Low-Temperature Aqueous-Phase Fischer Tropsch Synthesis

    SciTech Connect

    Wang, Hang; Zhou, Wu; Liu, JinXun; Si, Rui; Sun, Geng; Zhong, Mengqi; Su, Haiyan; Zhao, Huabo; Rodrigues, Jose; Pennycook, Stephen J; Idrobo Tapia, Juan C; Li, Weixue; Kou, Yuan; Ma, Ding

    2013-01-01

    Fischer Tropsch synthesis (FTS) is an important catalytic process for liquid fuel generation, which converts coal/shale gas/biomass-derived syngas (a mixture of CO and H2) to oil. While FTS is thermodynamically favored at low temperature, it is desirable to develop a new catalytic system that could allow working at a relatively low reaction temperature. In this article, we present a one-step hydrogenation reduction route for the synthesis of Pt Co nanoparticles (NPs) which were found to be excellent catalysts for aqueous-phase FTS at 433 K. Coupling with atomic-resolution scanning transmission electron microscopy (STEM) and theoretical calculations, the outstanding activity is rationalized by the formation of Co overlayer structures on Pt NPs or Pt Co alloy NPs. The improved energetics and kinetics from the change of the transition states imposed by the lattice mismatch between the two metals are concluded to be the key factors responsible for the dramatically improved FTS performance.

  11. Chain length dependence of {alpha}-olefin readsorption in Fischer-Tropsch synthesis

    SciTech Connect

    Kuipers, E.W.; Vinkenburg, I.H.; Oosterbeek, H.

    1995-03-01

    The total product concentration and the paraffin/olefin ratio have been measured up to C{sub 14} for Fischer-Tropsch synthesis on polycrystalline Co foils. The influences due to surface area, a wax coating, the H{sub 2}/CO ratio and flow velocity on concentration and selectivity have been determined. The paraffin/olefin ratio increases exponentially with chain length which is attributed to a chain-length-dependent olefin readsorption mechanism. The probability of readsorption depends on the heat of physisorption of the olefins on the catalyst as well as on their heat of dissolution in and their diffusivity through the product wax. All three factors predict an increase of the paraffin/olefin ratio with carbon number. Physisorption and dissolution are shown to cause a much stronger chain-length dependence than diffusion and will usually dominate. 36 refs., 9 figs.

  12. The role of electrophilic species in the Fischer-Tropsch reaction.

    PubMed

    Maitlis, Peter M; Zanotti, Valerio

    2009-04-07

    The heterogeneously catalysed Fischer-Tropsch (FT) synthesis converts syngas (CO+H2) into long chain hydrocarbons and is a key step in the economically important transformation of natural gas, coal, or biomass into liquid fuels, such as diesel. Catalyst surface studies indicate that the FT reaction starts when CO is activated at imperfections on the surfaces of late transition metals (Fe, Ru, Co, or Rh) and at interfaces with "islands" of promoters (Lewis acid oxides such as alumina or titania). Activation involves CO cleavage to generate a surface carbide, C(ad), which is sequentially hydrogenated to CHx(ad) species (x=1-4). An overview of practical aspects of the FT synthesis is followed by a discussion of the chief mechanisms that have been proposed for the formation of 1-alkenes by polymerisation of surface C1 species. These mechanisms have traditionally postulated rather non-polar intermediates, such as CH2(ad) and CH3(ad). However, electrophiles and nucleophiles are well-known to play key roles in the reactions of organic and organometallic compounds, and also in many reactions homogeneously catalysed by soluble metal complexes, including olefin polymerisation. We have now extended these concepts to the Fischer-Tropsch reaction, and show that the polymerisation reactions at polarising surfaces, such as oxide-metal interfaces, can be understood if the reactive chain carrier is an electrophilic species, such as the cationic methylidyne, CH(delta+)(ad). It is proposed that the key coupling step in C-C bond formation involves the interaction of the electrophilic methylidyne with an alkylidene (RCH(ad), R=H, alkyl), followed by an H-transfer to generate the homologous alkylidene: CHdelta+(ad)+RCH(ad)-->RCHCH(ad) and RCHCH(ad)+H(ad)-->RCH2CH(ad). If the reactions occur on non-polarising surfaces, an alternative C-C bond forming reaction such as the alkenyl+methylene, RCH=CH(ad)+CH2(ad)-->RCH=CHCH2(ad), can take place. This approach explains important aspects of the

  13. The selective catalytic cracking of Fischer-Tropsch liquids to high value transportation fuels. Final report

    SciTech Connect

    Schwartz, M.M.; Reagon, W.J.; Nicholas, J.J.; Hughes, R.D.

    1994-11-01

    Amoco Oil Company, investigated a selective catalytic cracking process (FCC) to convert the Fischer-Tropsch (F-T) gasoline and wax fractions to high value transportation fuels. The primary tasks of this contract were to (1) optimize the catalyst and process conditions of the FCC process for maximum conversion of F-T wax into reactive olefins for later production of C{sub 4}{minus}C{sub 8} ethers, and (2) use the olefin-containing light naphtha obtained from FCC processing of the F-T wax as feedstock for the synthesis of ethers. The catalytic cracking of F-T wax feedstocks gave high conversions with low activity catalysts and low process severities. HZSM-5 and beta zeolite catalysts gave higher yields of propylene, isobutylene, and isoamylenes but a lower gasoline yield than Y zeolite catalysts. Catalyst selection and process optimization will depend on product valuation. For a given catalyst and process condition, Sasol and LaPorte waxes gave similar conversions and product selectivities. The contaminant iron F-T catalyst fines in the LaPorte wax caused higher coke and hydrogen yields.

  14. CHAIN-LIMITING OPERATION OF FISCHER-TROPSCH REACTOR

    SciTech Connect

    Apostolos A. Nikolopoulos; Santosh K. Gangwal

    2003-06-01

    The use of pulsing in Fischer-Tropsch (FT) synthesis to limit the hydrocarbon chain growth and maximize the yield of diesel-range (C{sub 10}-C{sub 20}) products was examined on high-chain-growth-probability ({alpha} {ge} 0.9) FT catalysts. Pulsing experiments were conducted using a stainless-steel fixed-bed micro-reactor, equipped with both on-line (for the permanent gases and light hydrocarbons, C{sub 1}-C{sub 15}) and off-line (for the heavier hydrocarbons, C{sub 10}-C{sub 65}) gas chromatography analysis. Additional experiments were performed using a highly active attrition-resistant iron-based FT synthesis catalyst in a 1-liter continuous stirred-tank rector (CSTR). On both a Co-ZrO{sub 2}/SiO{sub 2} and a Co/Al{sub 2}O{sub 3} FT synthesis catalyst application of H{sub 2} pulsing causes significant increase in CO conversion, and only an instantaneous increase in undesirable selectivity to CH{sub 4}. Increasing the frequency of H{sub 2} pulsing enhances the selectivity to C{sub 10}-C{sub 20} compounds but the chain-growth probability {alpha} remains essentially unaffected. Increasing the duration of H{sub 2} pulsing results in enhancing the maximum obtained CO conversion and an instantaneous selectivity to CH{sub 4}. An optimum set of H{sub 2} pulse parameters (pulse frequency, pulse duration) is required for maximizing the yield of desirable diesel-range C{sub 10}-C{sub 20} products. Application of a suitable H{sub 2} pulse in the presence of added steam in the feed is a simple method to overcome the loss in activity and the shift in paraffin vs. olefin selectivity (increase in the olefin/paraffin ratio) caused by the excess steam. A decrease in syngas concentration has a strong suppressing effect on the olefin/paraffin ratio of the light hydrocarbon products. Higher syngas concentration can increase the chain growth probability {alpha} and thus allow for better evaluation of the effect of pulsing on FT synthesis. On a high-{alpha} Fe/K/Cu/SiO{sub 2} FT

  15. Effect of the porous structure of the support on hydrocarbon distribution in the Fischer-Tropsch reaction

    NASA Astrophysics Data System (ADS)

    Bartolini, Monica; Molina, Jhoanna; Alvarez, Juan; Goldwasser, Mireya; Pereira Almao, Pedro; Zurita, M. Josefina Pérez

    2015-07-01

    Emissions standards are increasingly stringent due mainly to its impact on the environment. Although the diesel engine is an attractive solution for carbon dioxide reduction, a challenge remains to simultaneously control nitrogen oxides and matter particulate emissions to accepted levels. On engine tests, it has been observed that Fischer-Tropsch diesel significantly reduces CO, HC, PAHs and particulate emissions compared to oil derived diesel. However, selectivity control in Fischer Tropsch Synthesis is still a key challenge due the Anderson-Schultz-Flory polymerization mechanism followed by hydrocarbon distribution. In this work we are presenting the first steps towards a new strategy that can tune, in one step, the selectivity to desired products by taking advantage of the shape selectivity properties of SBA-15 mesoporous silica used as support. Co-SBA-15 (30%wt) catalysts with different pore size were prepared by excess solution impregnation. Our results show that pore diameter not only affects the size and reducibility of Co particles but it also significantly influence the liquid products distribution, with the high molecular weight hydrocarbon fraction increasing on large pores, attributed to the existence of a shape selectivity effect induced by the textural properties of the catalyst namely its pore size and pore volume.

  16. Amino acids in a Fischer Tropsch type synthesis

    NASA Technical Reports Server (NTRS)

    Brown, D. L.; Lawless, J. G.

    1974-01-01

    One postulation is described for the presence of organic compounds in meteorites which states that they were formed during the condensation of the solar nebula. A viable laboratory simulation of these conditions can be modeled after the industrial Fischer Tropsch reaction, which is known to produce organic compounds called hydrocarbons. In this simulation, a mixture of carbon monoxide, hydrogen and ammonia is heated in the presence of iron meteorite. The reaction products for amino acids, a class of organic compounds important to life, were examined. A large number of these compounds is found in meteorites and other chemical evolution experiments, but only small quantities of a few amino acids were found in the present simulation work. These results are at odds with the existing literature in which many amino acids were reported.

  17. New developments in the field of Fischer-Tropsch synthesis

    SciTech Connect

    Brink, A.

    1985-01-01

    The Fischer-Tropsch synthesis for the production of transport fuels from syngas has been a commercial success in South Africa for nearly thirty years. It cannot be regarded as an entirely mature technology, though, and exciting prospects remain for improvements. The characteristics of the newer gasifiers such as Texaco, slagging BGC-Lurgi, Koppers-Totzek, Winkler and U-gas have to be carefully studied to determine their impact on the F T-synthesis. The wide carbon number selectivity of the F T-synthesis is not the drawback it is often assumbed to be since this can be easily rectified in the downstream refining section. Nevertheless, improved selectivity as regards the production of less methane and carbon, more ..cap alpha..-olefins and greater control over oxygenate production remain challenging possibilities.

  18. Synthesis gas solubility in Fischer-Tropsch slurry

    SciTech Connect

    Huang, S.H.

    1987-01-01

    A semi-flow apparatus is designed and constructed for the measurements of gas solubilities in molten waxes. Test data of CO/sub 2//toluene mixture show excellent agreement with literature data from a static apparatus. Five gases are studied: hydrogen, carbon monoxide, methane, ethane, and carbon dioxide. Data measurements are completed for each gas in n-eicosane (C/sub 20/), n-octacosane (C/sub 28/), and in n-hexatriacontane (C/sub 36/) as well as in an industrial wax over 100 to 300/sup 0/C and 10 to 50 atm. Solubilities of gas mixtures of H/sub 2/ + CO in n-C/sub 28/ are also measured at several equilibrium gas compositions. The gas K-value, defined as the ratio of the composition in the vapor phase to that in the liquid phase, is found independent as gas compositions within experimental errors. The Krichevski-Kasarnovsky equation represents well the data of binary systems. Henry's constants and partial molar volumes of gases at infinite dilution are determined from the equation. The Redlich-Kwong-Soave equation of state is modified to describe the vapor pressures of n-paraffins up to n-C/sub 100/. The modified equation is combined with a new mixing rule, whose derivation is based on a polymer solution theory, to correlate the data, and the results are satisfactory. Furthermore, the adjustable parameter can be correlated as an asymptotical function of the solvent molecular weight except for H/sub 2/ and CO at the lowest temperature. The modified equation with correlated parameter can predict the gas mixture solubilities in n-C/sub 28/. Also, gas solubilities in a wax mixture can be predicted if the wax is treated as a pure n-paraffin with the same number average molecular weight.

  19. Fischer-Tropsch synthesis in supercritical phase carbon dioxide: Recycle rates

    NASA Astrophysics Data System (ADS)

    Soti, Madhav

    With increasing oil prices and attention towards the reduction of anthropogenic CO2, the use of supercritical carbon dioxide for Fischer Tropsch Synthesis (FTS) is showing promise in fulfilling the demand of clean liquid fuels. The evidence of consumption of carbon dioxide means that it need not to be removed from the syngas feed to the Fischer Tropsch reactor after the gasification process. Over the last five years, research at SIUC have shown that FTS in supercritical CO2reduces the selectivities for methane, enhances conversion, reduces the net CO2produces in the coal to liquid fuels process and increase the life of the catalyst. The research has already evaluated the impact of various operating and feed conditions on the FTS for the once through process. We believe that the integration of unreacted feed recycle would enhance conversion, increase the yield and throughput of liquid fuels for the same reactor size. The proposed research aims at evaluating the impact of recycle of the unreacted feed gas along with associated product gases on the performance of supercritical CO2FTS. The previously identified conditions will be utilized and various recycle ratios will be evaluated in this research once the recycle pump and associated fittings have been integrated to the supercritical CO2FTS. In this research two different catalysts (Fe-Zn-K, Fe-Co-Zn-K) were analyzed under SC-FTS in different recycle rate at 350oC and 1200 psi. The use of recycle was found to improve conversion from 80% to close to 100% with both catalysts. The experiment recycle rate at 4.32 and 4.91 was clearly surpassing theoretical recycle curve. The steady state reaction rate constant was increased to 0.65 and 0.8 min-1 for recycle rate of 4.32 and 4.91 respectively. Carbon dioxide selectivity was decreased for both catalyst as it was converting to carbon monoxide. Carbon dioxide consumption was increased from 0.014 to 0.034 mole fraction. This concluded that CO2is being used in the system and

  20. Small-Scale Coal-Biomass to Liquids Production Using Highly Selective Fischer-Tropsch Synthesis

    SciTech Connect

    Gangwal, Santosh K.; McCabe, Kevin

    2015-04-30

    The research project advanced coal-to-liquids (CTL) and coal-biomass to liquids (CBTL) processes by testing and validating Chevron’s highly selective and active cobalt-zeolite hybrid Fischer-Tropsch (FT) catalyst to convert gasifier syngas predominantly to gasoline, jet fuel and diesel range hydrocarbon liquids, thereby eliminating expensive wax upgrading operations The National Carbon Capture Center (NCCC) operated by Southern Company (SC) at Wilsonville, Alabama served as the host site for the gasifier slip-stream testing/demonstration. Southern Research designed, installed and commissioned a bench scale skid mounted FT reactor system (SR-CBTL test rig) that was fully integrated with a slip stream from SC/NCCC’s transport integrated gasifier (TRIGTM). The test-rig was designed to receive up to 5 lb/h raw syngas augmented with bottled syngas to adjust the H2/CO molar ratio to 2, clean it to cobalt FT catalyst specifications, and produce liquid FT products at the design capacity of 2 to 4 L/day. It employed a 2-inch diameter boiling water jacketed fixed-bed heat-exchange FT reactor incorporating Chevron’s catalyst in Intramicron’s high thermal conductivity micro-fibrous entrapped catalyst (MFEC) packing to efficiently remove heat produced by the highly exothermic FT reaction.

  1. Pyrolysis-GCMS Analysis of Solid Organic Products from Catalytic Fischer-Tropsch Synthesis Experiments

    NASA Technical Reports Server (NTRS)

    Locke, Darren R.; Yazzie, Cyriah A.; Burton, Aaron S.; Niles, Paul B.; Johnson, Natasha M.

    2015-01-01

    Abiotic synthesis of complex organic compounds in the early solar nebula that formed our solar system is hypothesized to occur via a Fischer-Tropsch type (FTT) synthesis involving the reaction of hydrogen and carbon monoxide gases over metal and metal oxide catalysts. In general, at low temperatures (less than 200 C), FTT synthesis is expected to form abundant alkane compounds while at higher temperatures (greater than 200 C) it is expected to product lesser amounts of n-alkanes and greater amounts of alkene, alcohol, and polycyclic aromatic hydrocarbons (PAHs). Experiments utilizing a closed-gas circulation system to study the effects of FTT reaction temperature, catalysts, and number of experimental cycles on the resulting solid insoluble organic products are being performed in the laboratory at NASA Goddard Space Flight Center. These experiments aim to determine whether or not FTT reactions on grain surfaces in the protosolar nebula could be the source of the insoluble organic matter observed in meteorites. The resulting solid organic products are being analyzed at NASA Johnson Space Center by pyrolysis gas chromatography mass spectrometry (PY-GCMS). PY-GCMS yields the types and distribution of organic compounds released from the insoluble organic matter generated from the FTT reactions. Previously, exploratory work utilizing PY-GCMS to characterize the deposited organic materials from these reactions has been reported. Presented here are new organic analyses using magnetite catalyst to produce solid insoluble organic FTT products with varying reaction temperatures and number of experimental cycles.

  2. Fischer-Tropsch synthesis in supercritical reaction media. Progress report, July 10, 1992--September 30, 1992

    SciTech Connect

    Subramaniam, B.

    1992-10-01

    The goal of this research is to thoroughly investigate the feasibility of using supercritical fluid (SCF) solvent medium for carrying out Fischer-Tropsch (FT) synthesis. Research will address the systematic experimental investigations of FT synthesis over supported Fe and Co catalysts in a CSTR and in a fixed-bed reactor at typical synthesis temperatures (240-260{degrees}C). The SCF medium to be employed is n-Hexane (P{sub c} = 29.7 bar; {Tc} = 233.7{degrees}C), while n-Hexadecane will be employed as the liquid reaction medium. Overall conversion, product distribution and catalyst deactivation will be measured in each case for various feed H{sub 2}/CO ratios ranging from 0.5 to 2. Product analyses will be carried out using GC/TCD, GC/FID and GC/MS systems. The fresh and used catalysts will be characterized with respect to active metal dispersion, surface area and pore size distribution.

  3. Combinatorial computational chemistry approach for materials design: applications in deNOx catalysis, Fischer-Tropsch synthesis, lanthanoid complex, and lithium ion secondary battery.

    PubMed

    Koyama, Michihisa; Tsuboi, Hideyuki; Endou, Akira; Takaba, Hiromitsu; Kubo, Momoji; Del Carpio, Carlos A; Miyamoto, Akira

    2007-02-01

    Computational chemistry can provide fundamental knowledge regarding various aspects of materials. While its impact in scientific research is greatly increasing, its contributions to industrially important issues are far from satisfactory. In order to realize industrial innovation by computational chemistry, a new concept "combinatorial computational chemistry" has been proposed by introducing the concept of combinatorial chemistry to computational chemistry. This combinatorial computational chemistry approach enables theoretical high-throughput screening for materials design. In this manuscript, we review the successful applications of combinatorial computational chemistry to deNO(x) catalysts, Fischer-Tropsch catalysts, lanthanoid complex catalysts, and cathodes of the lithium ion secondary battery.

  4. Liquid phase Fischer-Tropsch (II) demonstration in the LaPorte Alternative Fuels Development Unit. Volume 1/2, Main Report. Final report

    SciTech Connect

    Bhatt, B.L.

    1995-09-01

    This report presents results from a demonstration of Liquid Phase Fischer-Tropsch (LPFT) technology in DOE`s Alternative Fuels Development Unit (AFDU) at LaPorte, Texas. The run was conducted in a bubble column at the AFDU in May--June 1994. The 10-day run demonstrated a very high level of reactor productivity for LPFT, more than five times the previously demonstrated productivity. The productivity was constrained by mass transfer limitations, perhaps due to slurry thickening as a result of carbon formation on the catalyst. With a cobalt catalyst or an improved iron catalyst, if the carbon formation can be avoided, there is significant room for further improvements. The reactor was operated with 0.7 H{sub 2}/CO synthesis gas in the range of 2400--11700 sl/hr-kg Fe, 175--750 psig and 270--300C. The inlet gas velocity ranged from 0.19 to 0.36 ft/sec. The demonstration was conducted at a pilot scale of 5 T/D. Catalyst activation with CO/N{sub 2} proceeded well. Initial catalyst activity was close to the expectations from the CAER autoclave runs. CO conversion of about 85% was obtained at the baseline condition. The catalyst also showed good water-gas shift activity and a low {alpha}. At high productivity conditions, reactor productivity of 136 grams of HC/hr -- liter of slurry volume was demonstrated, which was within the target of 120--150. However, mass transfer limitations were observed at these conditions. To alleviate these limitations and prevent excessive thickening, the slurry was diluted during the run. This enabled operations under kinetic control later in the run. But, the dilution resulted in lower conversion and reactor productivity. A new reactor internal heat exchanger, installed for high productivity conditions, performed well above design,and the system never limited the performance. The control can expected, the reactor temperature control needed manual intervention. The control can be improved by realigning the utility oil system.

  5. Moessbauer study of iron-carbide growth and Fischer-Tropsch activity

    SciTech Connect

    Rao, K.R.P.M.; Huggins, F.E.; Huffman, G.P.

    1995-12-31

    There is a need to establish a correlation between the Fischer-Tropsch (FT) activity of an iron-based catalyst and the catalyst phase during FT synthesis. The nature of iron phases formed during activation and FT synthesis is influenced by the gas used for activation. Moessbauer investigations of iron-based catalysts subjected to pretreatment in gas atmospheres containing mixtures of CO, H{sub 2}, and He have been carried out. Studies on UCI 1185-57 catalyst indicate that activation of the catalyst in CO leads to the formation of 100% magnetite and the magnetite formed gets rapidly converted to at least 90% of x-Fe{sub 5}C{sub 2} during activation. The x-Fe{sub 5}C{sub 2} formed during activation gets partly (= 25%) converted back to Fe{sub 3}O{sub 4} during FT synthesis and both x-Fe{sub 5}C{sub 2} and Fe{sub 3}O{sub 4} reach constant values. On the other hand, activation of the catalyst in synthesis gas leads to formation of Fe{sub 3}O{sub 4} and which is slowly converted to x-Fe{sub 5}C{sub 2} and e-Fe{sub 2.2}C during activation, and both carbide phases increase slowly during FT synthesis. FT synthesis activity is found to give rise to {approx} 70% (H2+CO) conversion in the case of CO activated catalyst as compared to {approx} 20% (H2+CO) conversion in the case of synthesis gas-activated catalyst.

  6. An Ab Initio Approach Towards Engineering Fischer-Tropsch Surface Chemistry

    SciTech Connect

    Matthew Neurock

    2006-09-11

    One of the greatest societal challenges over the next decade is the production of cheap, renewable energy for the 10 billion people that inhabit the earth. This will require the development of various energy sources which will likely include fuels derived from methane, coal, and biomass and alternatives sources such as solar, wind and nuclear energy. One approach will be to synthesize gasoline and other fuels from simpler hydrocarbons such as CO derived from methane or other U.S. based sources such as coal. Syngas (CO and H{sub 2}) can be readily converted into higher molecular weight hydrocarbons through Fischer-Tropsch synthesis. Fischer-Tropsch (FT) synthesis involves the adsorption and the activation of CO and H{sub 2}, the subsequent propagation steps including hydrogenation and carbon-carbon coupling, followed by chain termination reactions. The current commercial catalysts are supported Co and Co-alloys particles. This project set out with the following objectives in mind: (1) understand the reaction mechanisms that control FT kinetics, (2) predict how the intrinsic metal-adsorbate bond affects the sequence of elementary steps in FT, (3) establish the effects of the reaction environment on catalytic activity and selectivity, (4) construct a first-principles based algorithm that can incorporate the detailed atomic surface structure and simulate the kinetics for the myriad of elementary pathways that make up FT chemistry, and (5) suggest a set of optimal features such as alloy composition and spatial configuration, oxide support, distribution of defect sites. As part of this effort we devoted a significant portion of time to develop an ab initio based kinetic Monte Carlo simulation which can be used to follow FT surface chemistry over different transition metal and alloy surfaces defined by the user. Over the life of this program, we have used theory and have developed and applied stochastic Monte Carlo simulations in order to establish the fundamental

  7. Synthesis of adenine, guanine, cytosine, and other nitrogen organic compounds by a Fischer-Tropsch-like process.

    NASA Technical Reports Server (NTRS)

    Yang, C. C.; Oro, J.

    1971-01-01

    Study of the formation of purines, pyrimidines, and other bases from CO, H2, and NH3 under conditions similar to those used in the Fischer-Tropsch process. It is found that industrial nickel/iron alloy catalyzes the synthesis of adenine, guanine, cytosine, and other nitrogenous compounds from mixtures of CO, H2, and NH3 at temperatures of about 600 C. Sufficient sample was accumulated to isolate as solid products adenine, guanine, and cytosine, which were identified by infrared spectrophotometry. In the absence of nickel/iron catalyst, at 650 C, or in the presence of this catalyst, at 450 C, no purines or pyrimidines were synthesized. These results confirm and extend some of the work reported by Kayatsu et al. (1968).

  8. The influence of the potassium promoter on the kinetics and thermodynamics of CO adsorption on a bulk iron catalyst applied in Fischer-Tropsch synthesis: a quantitative adsorption calorimetry, temperature-programmed desorption, and surface hydrogenation study.

    PubMed

    Graf, Barbara; Muhler, Martin

    2011-03-07

    The adsorption of carbon monoxide on an either unpromoted or potassium-promoted bulk iron catalyst was investigated at 303 K and 613 K by means of pulse chemisorption, adsorption calorimetry, temperature-programmed desorption and temperature-programmed surface reaction in hydrogen. CO was found to adsorb mainly molecularly in the absence of H(2) at 303 K, whereas the presence of H(2) induced CO dissociation at higher temperatures leading to the formation of CH(4) and H(2)O. The hydrogenation of atomic oxygen chemisorbed on metallic iron was found to occur faster than the hydrogenation of atomically adsorbed carbon. At 613 K CO adsorption occurred only dissociatively followed by recombinative CO(2) formation according to C(ads) + 2O(ads)→ CO(2(g)). The presence of the potassium promoter on the catalyst surface led to an increasing strength of the Fe-C bond both at 303 K and 613 K: the initial differential heat of molecular CO adsorption on the pure iron catalyst at 303 K amounted to 102 kJ mol(-1), whereas it increased to 110 kJ mol(-1) on the potassium-promoted sample, and the initial differential heat of dissociative CO adsorption on the unpromoted iron catalyst at 613 K amounted to 165 kJ mol(-1), which increased to 225 kJ mol(-1) in the presence of potassium. The calorimetric CO adsorption experiments also reveal a change of the energetic distribution of the CO adsorption sites present on the catalyst surface induced by the potassium promoter, which was found to block a fraction of the CO adsorption sites.

  9. First-principles calculations of Fischer-Tropsch processes catalyzed by nitrogenase enzymes

    NASA Astrophysics Data System (ADS)

    Varley, Joel; Grabow, Lars; Nørskov, Jens

    2012-02-01

    The nitrogenase enzyme system of the bacteria Azotobacter vinelandii, which is used in nature to catalyze ammonia synthesis, has been found recently to catalyze the efficient conversion of carbon monoxide (CO) into hydrocarbons under ambient temperature and pressure [1]. These findings indicate that nitrogenase enzymes could inspire more efficient catalysts for electrochemical CO and CO2 reduction to liquid fuels. The nitrogenase variants, in which vanadium substitutes the molybdenum in the active site of the enzyme, show distinct features in their reaction pathways to hydrocarbon production. To compare and contrast the catalytic properties of these nitrogenase enzymes, we perform first-principles calculations to map out the reaction pathways for both nitrogen fixation and for the reduction of CO to higher-order hydrocarbons. We discuss the trends and differences between the two enzymes and detail the relevant chemical species and rate-limiting steps involved in the reactions. By utilizing this information, we predict the electrochemical conditions necessary for the catalytic reduction of CO into fuels by the nitrogenase active sites, analogous to a Fischer-Tropsch process requiring less extreme conditions. [4pt] [1] Y. Hu, C.C. Lee, M.W. Ribbe, Science 333, 753 (2011)

  10. Meteorites, Organics and Fischer-Tropsch Type Reaction: Production and Destruction

    NASA Technical Reports Server (NTRS)

    Johnson, Natasha M.; Burton, A. S.; Nurth, J. A., III

    2011-01-01

    There has been an ongoing debate about the relative importance about the various chemical reactions that fonned organics in the early solar system. One proposed method that has long been recognized as a potential source of organics is Fischer-Tropsch type (FTT) synthesis. This process is commonly used in industry to produce fuels (i.e., complex hydrocarbons) by catalytic hydrogenation of carbon monoxide. Hill and Nuth were the first to publish results of FTT experiments that also included Haber-Bosch (HB) processes (hydrogenation of nitrogen. Their findings included the production of nitrilebearing compounds as well as trace amounts of methyl amine. Previous experience with these reactions revealed that the organic coating deposited on the grains is also an efficient catalyst and that the coating is composed of insoluble organic matter (10M) and could be reminiscent of the organic matrix found in some meteorites. This current set of FTT-styled experiments tracks the evolution of a set of organics, amino acids, in detail.

  11. Platinum-modulated cobalt nanocatalysts for low-temperature aqueous-phase Fischer-Tropsch synthesis.

    PubMed

    Wang, Hang; Zhou, Wu; Liu, Jin-Xun; Si, Rui; Sun, Geng; Zhong, Meng-Qi; Su, Hai-Yan; Zhao, Hua-Bo; Rodriguez, Jose A; Pennycook, Stephen J; Idrobo, Juan-Carlos; Li, Wei-Xue; Kou, Yuan; Ma, Ding

    2013-03-13

    Fischer-Tropsch synthesis (FTS) is an important catalytic process for liquid fuel generation, which converts coal/shale gas/biomass-derived syngas (a mixture of CO and H2) to oil. While FTS is thermodynamically favored at low temperature, it is desirable to develop a new catalytic system that could allow working at a relatively low reaction temperature. In this article, we present a one-step hydrogenation-reduction route for the synthesis of Pt-Co nanoparticles (NPs) which were found to be excellent catalysts for aqueous-phase FTS at 433 K. Coupling with atomic-resolution scanning transmission electron microscopy (STEM) and theoretical calculations, the outstanding activity is rationalized by the formation of Co overlayer structures on Pt NPs or Pt-Co alloy NPs. The improved energetics and kinetics from the change of the transition states imposed by the lattice mismatch between the two metals are concluded to be the key factors responsible for the dramatically improved FTS performance.

  12. On the origin of the cobalt particle size effects in Fischer-Tropsch catalysis.

    PubMed

    den Breejen, J P; Radstake, P B; Bezemer, G L; Bitter, J H; Frøseth, V; Holmen, A; de Jong, K P

    2009-05-27

    The effects of metal particle size in catalysis are of prime scientific and industrial importance and call for a better understanding. In this paper the origin of the cobalt particle size effects in Fischer-Tropsch (FT) catalysis was studied. Steady-State Isotopic Transient Kinetic Analysis (SSITKA) was applied to provide surface residence times and coverages of reaction intermediates as a function of Co particle size (2.6-16 nm). For carbon nanofiber supported cobalt catalysts at 210 degrees C and H(2)/CO = 10 v/v, it appeared that the surface residence times of reversibly bonded CH(x) and OH(x) intermediates increased, whereas that of CO decreased for small (<6 nm) Co particles. A higher coverage of irreversibly bonded CO was found for small Co particles that was ascribed to a larger fraction of low-coordinated surface sites. The coverages and residence times obtained from SSITKA were used to describe the surface-specific activity (TOF) quantitatively and the CH(4) selectivity qualitatively as a function of Co particle size for the FT reaction (220 degrees C, H(2)/CO = 2). The lower TOF of Co particles <6 nm is caused by both blocking of edge/corner sites and a lower intrinsic activity at the small terraces. The higher methane selectivity of small Co particles is mainly brought about by their higher hydrogen coverages.

  13. Predicting the performance of system for the co-production of Fischer-Tropsch synthetic liquid and power from coal

    SciTech Connect

    Wang, X.; Xiao, Y.; Xu, S.; Guo, Z.

    2008-01-15

    A co-production system based on Fischer-Tropsch (FT) synthesis reactor and gas turbine was simulated and analyzed. Syngas from entrained bed coal gasification was used as feedstock of the low-temperature slurry phase Fischer-Tropsch reactor. Raw synthetic liquid produced was fractioned and upgraded to diesel, gasoline, and liquid petrol gas (LPG). Tail gas composed of unconverted syngas and FT light components was fed to the gas turbine. Supplemental fuel (NG, or refinery mine gas) might be necessary, which was dependent on gas turbine capacity expander through flow capacity, etc. FT yield information was important to the simulation of this co-production system. A correlation model based on Mobil's two step pilot plant was applied. User models that can predict product yields and cooperate with other units were embedded into Aspen plus simulation. Performance prediction of syngas fired gas turbine was the other key of this system. The increase in mass flow through the turbine affects the match between compressor and turbine operating conditions. The calculation was carried out by GS software developed by Politecnico Di Milano and Princeton University. Various cases were investigated to match the FT synthesis island, power island, and gasification island in co-production systems. Effects of CO{sub 2} removal/LPG recovery, co-firing, and CH{sub 4} content variation were studied. Simulation results indicated that more than 50% of input energy was converted to electricity and FT products. Total yield of gasoline, diesel, and LPG was 136-155 g/N m{sup 3} (CO+H{sub 2}). At coal feed of 21.9 kg/s, net electricity exported to the grid was higher than 100 MW. Total production of diesel and gasoline (and LPG) was 118,000 t (134,000 t)/year. Under the economic analysis conditions assumed in this paper the co-production system was economically feasible.

  14. Development of Detailed Kinetic Models for Fischer-Tropsch Fuels

    SciTech Connect

    Westbrook, C K; Pitz, W J; Carstensen, H; Dean, A M

    2008-10-28

    Fischer-Tropsch (FT) fuels can be synthesized from a syngas stream generated by the gasification of biomass. As such they have the potential to be a renewable hydrocarbon fuel with many desirable properties. However, both the chemical and physical properties are somewhat different from the petroleum-based hydrocarbons that they might replace, and it is important to account for such differences when considering using them as replacements for conventional fuels in devices such as diesel engines and gas turbines. FT fuels generally contain iso-alkanes with one or two substituted methyl groups to meet the pour-point specifications. Although models have been developed for smaller branched alkanes such as isooctane, additional efforts are required to properly capture the kinetics of the larger branched alkanes. Recently, Westbrook et al. developed a chemical kinetic model that can be used to represent the entire series of n-alkanes from C{sub 1} to C{sub 16} (Figure 1). In the current work, the model is extended to treat 2,2,4,4,6,8,8-heptamethylnonane (HMN), a large iso-alkane. The same reaction rate rules used in the iso-octane mechanism were incorporated in the HMN mechanism. Both high and low temperature chemistry was included so that the chemical kinetic model would be applicable to advanced internal combustion engines using low temperature combustion strategies. The chemical kinetic model consists of 1114 species and 4468 reactions. Concurrently with this effort, work is underway to improve the details of specific reaction classes in the mechanism, guided by high-level electronic structure calculations. Attention is focused upon development of accurate rate rules for abstraction of the tertiary hydrogens present in branched alkanes and properly accounting for the pressure dependence of the ?-scission, isomerization, and R + O{sub 2} reactions.

  15. Thermal Stability Testing of a Fischer-Tropsch Fuel and Various Blends with Jet A

    NASA Technical Reports Server (NTRS)

    Klettlinger, Jennifer Suder; Surgenor, Angela; Yen, Chia

    2010-01-01

    Fischer-Tropsch (F-T) jet fuel composition differs from petroleum-based, conventional commercial jet fuel because of differences in feedstock and production methodology. Fischer-Tropsch fuel typically has a lower aromatic and sulfur content and consists primarily of iso and normal parafins. The ASTM D3241 specification for Jet Fuel Thermal Oxidation Test (JFTOT) break point testing method was used to test the breakpoint of a baseline conventional Jet A, a commercial grade F-T jet fuel, and various blends of this F-T fuel in Jet A. The testing completed in this report was supported by the NASA Fundamental Aeronautics Subsonics Fixed Wing Project.

  16. Fischer-Tropsch synthesis. Evaluation of an aluminum small channel reactor.

    PubMed

    Sparks, D E; Vallee, S; Jia, Zhijun; Shafer, W D; Davis, B H

    2017-02-10

    Fischer-Tropsch synthesis was conducted in a small channel compact heat exchange reactor that was constructed of aluminum. While limited to lower temperature-pressure regions of the Fischer-Tropsch synthesis, the reactor could be operated in an isothermal mode with nearly a constant temperature along the length of the channel. The results obtained with the compact heat exchange reactor were similar to those obtained in the isothermal continuous stirred tank reactor, with respect to both activity and selectivity. Following a planned or unplanned shutdown, the reactor could be restarted to produce essentially the same catalytic activity and selectivity as before the shutdown.

  17. Fischer-Tropsch reaction on a thermally conductive and reusable silicon carbide support.

    PubMed

    Liu, Yuefeng; Ersen, Ovidiu; Meny, Christian; Luck, Francis; Pham-Huu, Cuong

    2014-05-01

    The Fischer-Tropsch (FT) process, in which synthesis gas (syngas) derived from coal, natural gas, and biomass is converted into synthetic liquid fuels and chemicals, is a strongly exothermic reaction, and thus, a large amount of heat is generated during the reaction that could severely modify the overall selectivity of the process. In this Review, we report the advantages that can be offered by different thermally conductive supports, that is, carbon nanomaterials and silicon carbide, pure or doped with different promoters, for the development of more active and selective FT catalysts. This Review follows a discussion regarding the clear trend in the advantages and drawbacks of these systems in terms of energy efficiency and catalytic performance for this most-demanded catalytic process. It is demonstrated that the use of a support with an appropriate pore size and thermal conductivity is an effective strategy to tune and improve the activity of the catalyst and to improve product selectivity in the FT process. The active phase and the recovery of the support, which also represents a main concern in terms of the large amount of FT catalyst used and the cost of the active cobalt phase, is also discussed within the framework of this Review. It is expected that a thermally conductive support such as β-SiC will not only improve the development of the FT process, but that it will also be part of a new support for different catalytic processes for which high catalytic performance and selectivity are strongly needed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Evidence of Structure Sensitivity in the Fischer-Tropsch Reaction on Model Cobalt Nanoparticles by Time-Resolved Chemical Transient Kinetics.

    PubMed

    Ralston, Walter T; Melaet, Gérôme; Saephan, Tommy; Somorjai, Gabor A

    2017-06-19

    The Fischer-Tropsch process, or the catalytic hydrogenation of carbon monoxide (CO), produces long chain hydrocarbons and offers an alternative to the use of crude oil for chemical feedstocks. The observed size dependence of cobalt (Co) catalysts for the Fischer-Tropsch reaction was studied with colloidally prepared Co nanoparticles and a chemical transient kinetics reactor capable of measurements under non-steady-state conditions. Co nanoparticles of 4.3 nm and 9.5 nm diameters were synthesized and tested under atmospheric pressure conditions and H2 /CO=2. Large differences in carbon coverage (ΘC ) were observed for the two catalysts: the 4.3 nm Co catalyst has a ΘC less than one while the 9.5 nm Co catalyst supports a ΘC greater than two. The monomer units present on the surface during reaction are identified as single carbon species for both sizes of Co nanoparticles, and the major CO dissociation site is identified as the B5 -B geometry. The difference in activity of Co nanoparticles was found to be a result of the structure sensitivity caused by the loss of these specific types of sites at smaller nanoparticle sizes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. FISCHER-TROPSCH FUELS PRODUCTION AND DEMONSTRATION PROJECT

    SciTech Connect

    Stephen P. Bergin

    2003-04-23

    This project has two primary purposes: (1) Build a small-footprint (SFP) fuel production plant to prove the feasibility of this relatively transportable technology on an intermediate scale (i.e. between laboratory-bench and commercial capacity) and produce as much as 150,000 gallons of hydrogen-saturated Fischer-Tropsch (FT) diesel fuel; and (2) Use the virtually sulfur-free fuel produced to demonstrate (over a period of at least six months) that it can not only be used in existing diesel engines, but that it also can enable significantly increased effectiveness and life of the next-generation exhaust-after-treatment emission control systems that are currently under development and that will be required for future diesel engines. Furthermore, a well-to-wheels economic analysis will be performed to characterize the overall costs and benefits that would be associated with the actual commercial production, distribution and use of such FT diesel fuel made by the process under consideration, from the currently underutilized (or entirely un-used) energy resources targeted, primarily natural gas that is stranded, sub-quality, off-shore, etc. During the first year of the project, which is the subject of this report, there have been two significant areas of progress: (1) Most of the preparatory work required to build the SFP fuel-production plant has been completed, and (2) Relationships have been established, and necessary project coordination has been started, with the half dozen project-partner organizations that will have a role in the fuel demonstration and evaluation phase of the project. Additional project tasks directly related to the State of Alaska have also been added to the project. These include: A study of underutilized potential Alaska energy resources that could contribute to domestic diesel and distillate fuel production by providing input energy for future commercial-size SFP fuel production plants; Demonstration of the use of the product fuel in a heavy

  20. Fischer Tropsch synthesis in supercritical fluids. Quarterly technical progress report, January 1, 1995--March 31, 1995

    SciTech Connect

    Akgerman, A.; Bukur, D.B.

    1996-05-01

    Our objectives for this quarter were: (1) to install and test the temperature probe and the flammable gas detector: (2) to conduct Fischer-Tropsch synthesis experiments at baseline conditions and at a high pressure in order to test the newly constructed fixed bed reactor assembly.

  1. Design of slurry reactor for indirect liquefaction applications

    SciTech Connect

    Prakash, A.; Bendale, P.G.

    1991-01-01

    The objective of this project is to design and model a conceptual slurry reactor for two indirect liquefaction applications; (1) production of methanol and (2) production of hydrocarbon fuels via Fischer-Tropsch route. A slurry reactor is defined here as a three-phase bubble column reactor using a fine catalyst particle suspension in a high molecular weight liquid. The feed gas is introduced through spargers. It then bubbles through the column providing the agitation necessary for catalyst suspension and mass transfer. The reactor models for the two processes have been formulated using computer simulation. Process data, kinetic and thermodynamic data, heat and mass transfer data and hydrodynamic data have been used in the mathematical models to describe the slurry reactor for each of the two processes. Available data from process development units and demonstration units were used to test and validate the models. Commercial size slurry reactors for methanol and Fischer-Tropsch synthesis were sized using reactor models developed in this report.

  2. Design of slurry reactor for indirect liquefaction applications. Final report

    SciTech Connect

    Prakash, A.; Bendale, P.G.

    1991-12-31

    The objective of this project is to design and model a conceptual slurry reactor for two indirect liquefaction applications; (1) production of methanol and (2) production of hydrocarbon fuels via Fischer-Tropsch route. A slurry reactor is defined here as a three-phase bubble column reactor using a fine catalyst particle suspension in a high molecular weight liquid. The feed gas is introduced through spargers. It then bubbles through the column providing the agitation necessary for catalyst suspension and mass transfer. The reactor models for the two processes have been formulated using computer simulation. Process data, kinetic and thermodynamic data, heat and mass transfer data and hydrodynamic data have been used in the mathematical models to describe the slurry reactor for each of the two processes. Available data from process development units and demonstration units were used to test and validate the models. Commercial size slurry reactors for methanol and Fischer-Tropsch synthesis were sized using reactor models developed in this report.

  3. Moessbauer study of iron-carbide growth and Fischer-Tropsch activity

    SciTech Connect

    Rao, K.R.P.M.; Huggins, F.E.; Huffman, G.P.

    1995-12-31

    There is a need to establish a correlation between the Fischer-Tropsch (FT) activity of an iron-based catalyst and the catalyst phase during FT synthesis. The nature of iron phases formed during activation and FT synthesis is influenced by the nature of the gas and pressure apart from other parameters like temperature, flow rate etc., used for activation. Moessbauer investigations of iron-based catalysts subjected to pretreatment at two different pressures in gas atmospheres containing mixtures of CO, H{sub 2}, and He have been carried out. Studies on UCI 1185-57 (64%Fe{sub 2}O{sub 3}/5%CuO/1%K{sub 2}O/30% Kaolin) catalyst indicate that activation of the catalyst in CO at 12 atms. leads to the formation of 100% magnetite and the magnetite formed gets rapidly converted to at least 90% of {chi}-Fe{sub 5}C{sub 2} during activation. The FT activity was found to be good at 70-80% of (H{sub 2}+CO) conversion. On the other hand, activation. The FT activity was found to be good at 70-80% of (H{sub 2}+CO) conversion. On the other hand, activation of the catalyst in synthesis gas at 12 atms. leads to formation of Fe{sub 3}O{sub 4} and it gets sluggishly converted to {chi}-Fe{sub 5}C{sub 2} and {epsilon}-Fe{sub 2.2}C during activation and both continue to grow slowly during FT synthesis. FT activity is found to be poor. Pretreatment of the catalyst, 100fe/3.6Si/0.71K at a low pressure of 1 atms. in syngas gave rise to the formation of {chi}-Fe{sub 5}C{sub 2} and good FT activity. On the other hand, pretreatment of the catalyst, 100Fe/3.6Si/0.71K at a relatively high pressure of 12 atms. in syngas did not give rise to the formation any carbide and FT activity was poor.

  4. Parametric study of Fischer-Tropsch synthesis in supercritical phase carbon dioxide

    NASA Astrophysics Data System (ADS)

    Gautam, Jitendra

    The results from studies on Fischer Tropsch synthesis wherein syngas was dissolved in CO2 are presented. The syngas generally used was typical of that obtained from coal gasification, i.e. CO:H2 of one. Under these conditions Co-based catalysts without any water gas shift catalyst does not perform well while Fe -- based catalysts have been found to be useful. However, the Fe based catalysts have a propensity towards CO2 selectivity via the primary FT reaction, Boudouard reaction and the water gas shift reaction. The use of CO2 as a solvent was found to suppress the CO2 and CH4 selectivity while enhancing the hydrocarbon selectivity and CO conversion when FT synthesis was conducted using coal derived syngas on Fe-Zn-K catalysts. The effects were found to be significantly pronounced at pressures higher than or equal to 1200 psig. It should be noted that CO2 is supercritical at pressures higher than 1070 psig and 31.4 °C. The effect of CO2 partial pressure, reactor pressure, reaction temperature, catalyst loading and H 2:CO ratio in syngas on the liquid product distribution was evaluated. Some of the notable findings include product tenability by varying temperature and pressure as well as varying the CO2 partial pressure and the syngas composition. Increasing the reactor pressure was found to favor longer chain growth. In addition, it was noted that the ratio between CO2:syngas in the reaction mixture is an important factor in the liquid product distribution. A higher value of the ratio is seen to favor hydrocarbon synthesis, while a lower value of the ratio favors oxygenate production particularly pentanols and butanols. In addition, the data on the once through fractionation of the products utilizing the solubilities in supercritical CO2 and pressure tuning were encouraging. It was found that the products can be easily fractionated into narrow carbon chain length distributions downstream of the reactor by simply reducing the pressures in each collection vessel. It

  5. Organic Analysis of Catalytic Fischer-Tropsch Type Synthesis Products: Are they Similar to Organics in Chondritic Meteorites?

    NASA Technical Reports Server (NTRS)

    Yazzie, Cyriah A.; Locke, Darren R.; Johnson, Natasha M.

    2014-01-01

    Fischer-Tropsch Type (FTT) synthesis of organic compounds has been hypothesized to occur in the early solar nebula that formed our Solar System. FTT is a collection of abiotic chemical reactions that convert a mixture of carbon monoxide and hydrogen over nano-catalysts into hydrocarbons and other more complex aromatic compounds. We hypothesized that FTT can generate similar organic compounds as those seen in chondritic meteorites; fragments of asteroids that are characteristic of the early solar system. Specific goals for this project included: 1) determining the effects of different FTT catalyst, reaction temperature, and cycles on organic compounds produced, 2) imaging of organic coatings found on the catalyst, and 3) comparison of organic compounds produced experimentally by FTT synthesis and those found in the ordinary chondrite LL5 Chelyabinsk meteorite. We used Pyrolysis Gas Chromatography Mass Spectrometry (PY-GCMS) to release organic compounds present in experimental FTT and meteorite samples, and Scanning Electron Microscopy (SEM) to take images of organic films on catalyst grains.

  6. Nitrogen isotope fractionations in the Fischer-Tropsch synthesis and in the Miller-Urey reaction

    NASA Technical Reports Server (NTRS)

    King, C.-C.; Clayton, R. N.; Hayatsu, R.; Studier, M. H.

    1979-01-01

    Nitrogen isotope fractionations have been measured in Fischer-Tropsch and Miller-Urey reactions in order to determine whether these processes can account for the large N-15/N-14 ratios found in organic matter in carbonaceous chondrites. Polymeric material formed in the Fischer-Tropsch reaction was enriched in N-15 by only 3 per mil relative to the starting material (NH3). The N-15 enrichment in polymers from the Miller-Urey reaction was 10-12 per mil. Both of these fractionations are small compared to the 80-90 per mil differences observed between enstatite chondrites and carbonaceous chondrites. These large differences are apparently due to temporal or spatial variations in the isotopic composition of nitrogen in the solar nebula, rather than to fractionation during the production of organic compounds.

  7. Effect of Aromatic Concentration of a Fischer-Tropsch Fuel on Thermal Stability

    NASA Technical Reports Server (NTRS)

    Klettlinger, Jennifer Lindsey Suder

    2012-01-01

    Fischer-Tropsch (F-T) jet fuel composition differs from petroleum-based, conventional commercial jet fuel because of differences in feedstock and production methodology. Fischer­ Tropsch fuel typically has a lower aromatic and sulfur content and consists primarily of iso and normal parafins. The ASTM D3241 specification for Jet Fuel Thermal Oxidation Test (JFTOT) break point testing method was used to test the breakpoint of a baseline commercial grade F-T jet fuel, and various blends of this F-T fuel with an aromatic solution. The goal of this research is to determine the effect of aromatic content on the thermal stability of Fischer-Tropsch fuel. The testing completed in this report was supported by the NASA Fundamental Aeronautics Subsonics Fixed Wing Project.

  8. Incorporation of catalytic dehydrogenation into fischer-tropsch synthesis to significantly reduce carbon dioxide emissions

    DOEpatents

    Huffman, Gerald P.

    2012-11-13

    A new method of producing liquid transportation fuels from coal and other hydrocarbons that significantly reduces carbon dioxide emissions by combining Fischer-Tropsch synthesis with catalytic dehydrogenation is claimed. Catalytic dehydrogenation (CDH) of the gaseous products (C1-C4) of Fischer-Tropsch synthesis (FTS) can produce large quantities of hydrogen while converting the carbon to multi-walled carbon nanotubes (MWCNT). Incorporation of CDH into a FTS-CDH plant converting coal to liquid fuels can eliminate all or most of the CO.sub.2 emissions from the water-gas shift (WGS) reaction that is currently used to elevate the H.sub.2 level of coal-derived syngas for FTS. Additionally, the FTS-CDH process saves large amounts of water used by the WGS reaction and produces a valuable by-product, MWCNT.

  9. Fischer Tropsch synthesis in supercritical fluids. Quarterly technical progress report, October 1, 1993--December 31, 1993

    SciTech Connect

    Akgerman, A.; Bukur, D.B.

    1993-12-31

    Objectives for the first quarter for Task A, Diffusion Coefficients of F-T Products in Supercritical Fluids, were to measure diffusion coefficients of 1-tetradecene in subcritical propane and the diffusion coefficients of 1-octene and 1-tetradecene in subcritical propane and the diffusion coefficients of 1-octene and 1-tetradecene in subcritical and supercritical ethane. We planned to use ethane as a solvent because its lower critical temperature enabled measurements without modification of the existing unit. Our objective was to investigate the behavior of the diffusion coefficients in crossing from subcritical to supercritical conditions. Objectives for Task B, Fischer Tropsch reaction related studies, were: (1) to install and test the temperature probe and the flammable gas detector: (2) to conduct Fischer-Tropsch experiments at baseline conditions and at a high pressure in order to test the newly constructed fixed bed reactor assembly. Accomplishments and problems, are presented.

  10. Nitrogen isotope fractionations in the Fischer-Tropsch synthesis and in the Miller-Urey reaction

    NASA Technical Reports Server (NTRS)

    King, C.-C.; Clayton, R. N.; Hayatsu, R.; Studier, M. H.

    1979-01-01

    Nitrogen isotope fractionations have been measured in Fischer-Tropsch and Miller-Urey reactions in order to determine whether these processes can account for the large N-15/N-14 ratios found in organic matter in carbonaceous chondrites. Polymeric material formed in the Fischer-Tropsch reaction was enriched in N-15 by only 3 per mil relative to the starting material (NH3). The N-15 enrichment in polymers from the Miller-Urey reaction was 10-12 per mil. Both of these fractionations are small compared to the 80-90 per mil differences observed between enstatite chondrites and carbonaceous chondrites. These large differences are apparently due to temporal or spatial variations in the isotopic composition of nitrogen in the solar nebula, rather than to fractionation during the production of organic compounds.

  11. Effect of Aromatic Concentration of a Fischer-Tropsch Fuel on Thermal Stability

    NASA Technical Reports Server (NTRS)

    Klettlinger, Jennifer Lindsey Suder

    2012-01-01

    Fischer-Tropsch (F-T) jet fuel composition differs from petroleum-based, conventional commercial jet fuel because of differences in feedstock and production methodology. Fischer­ Tropsch fuel typically has a lower aromatic and sulfur content and consists primarily of iso and normal parafins. The ASTM D3241 specification for Jet Fuel Thermal Oxidation Test (JFTOT) break point testing method was used to test the breakpoint of a baseline commercial grade F-T jet fuel, and various blends of this F-T fuel with an aromatic solution. The goal of this research is to determine the effect of aromatic content on the thermal stability of Fischer-Tropsch fuel. The testing completed in this report was supported by the NASA Fundamental Aeronautics Subsonics Fixed Wing Project.

  12. Synthesis and catalysis of location-specific cobalt nanoparticles supported by multiwall carbon nanotubes for Fischer-Tropsch synthesis.

    PubMed

    Zhu, Yuan; Ye, Yingchun; Zhang, Shiran; Leong, Mark E; Tao, Franklin Feng

    2012-05-29

    Cobalt nanoparticles located on the concave internal surface of multiwalled carbon nanotubes (Co-in-MW-CNTs) and the convex external surface of MW-CNTs (Co-on-MW-CNTs) were synthesized. Their catalytic performances in Fischer-Tropsch synthesis (FTS) were investigated. A correlation between the location, pretreatment, and surface chemistry of the cobalt nanoparticles and the catalytic selectivity in FTS was built. It is found that the selectivity in production of C(5+) molecules through FTS on cobalt catalysts supported by MW-CNTs depends on activation temperatures and surface chemistry of the cobalt nanoparticles. A pretreatment at 300 °C in H(2) flow results in a different surface chemistry for Co-in-MW-CNTs than for Co-on-MW-CNTs, which leads to a difference in selectvity to the production of C(5+) molecules. Pretreatment at a relatively high temperature, 400 °C, in H(2) flow produces completely reduced Co nanoparticles in Co-in-MW-CNTs and Co-on-MW-CNTs. There is no signifcant difference in catalytic selectivity between the two catalysts upon pretreatment at 400 °C. The absence of a significant difference in catalytic selectivity of metallic Co-on-MW-CNTs and metallic Co-in-MW-CNTs suggests that the electronic effect of the MW-CNT support does not significantly affect the C(5+) selectivity of cobalt catalysts in FTS.

  13. An Ab Initio Approach Towards Engineering Fischer-Tropsch Surface Chemistry

    SciTech Connect

    Matthew Neurock

    2005-06-13

    As petroleum prices continue to rise and the United States seeks to reduce its dependency on foreign oil, there is a renewed interest in the research and development of more efficient and alternative energy sources, such as fuel cells. One approach is to utilize processes that can produce long-chain hydrocarbons from other sources. One such reaction is Fischer-Tropsch synthesis. Fischer-Tropsch synthesis is a process by which syngas (CO and H{sub 2}) is converted to higher molecular weight hydrocarbons. The reaction involves a complex set of bond-breaking and bond-making reactions, such as CO and H{sub 2} activation, hydrocarbon hydrogenation reactions, and hydrocarbon coupling reactions. This report details our initial construction of an ab initio based kinetic Monte Carlo code that can be used to begin to simulate Fischer-Tropsch synthesis over model Co(0001) surfaces. The code is based on a stochastic kinetic formalism that allows us to explicitly track the transformation of all reactants, intermediates and products. The intrinsic kinetics for the simulations were derived from the ab initio results that we reported in previous year summaries.

  14. Emissions characteristics of Military Helicopter Engines Fueled with JP-8 and a Fischer-Tropsch Fuel

    SciTech Connect

    Corporan, E.; DeWitt, M.; Klingshirn, Christopher D; Striebich, Richard; Cheng, Mengdawn

    2010-01-01

    The rapid growth in aviation activities and more stringent U.S. Environmental Protection Agency regulations have increased concerns regarding aircraft emissions, due to their harmful health and environmental impacts, especially in the vicinity of airports and military bases. In this study, the gaseous and particulate-matter emissions of two General Electric T701C engines and one T700 engine were evaluated. The T700 series engines power the U.S. Army's Black Hawk and Apache helicopters. The engines were fueled with standard military JP-8 fuel and were tested at three power settings. In addition, one of the T701C engines was operated on a natural-gas-derived Fischer-Tropsch synthetic paraffinic kerosene jet fuel. Test results show that the T701C engine emits significantly lower particulate-matter emissions than the T700 for all conditions tested. Particulate-matter mass emission indices ranged from 0.2-1.4 g/kg fuel for the T700 and 0.2-0.6 g/kg fuel for the T701C. Slightly higher NOx and lower CO emissions were observed for the T701C compared with the T700. Operation of the T701C with the Fischer-Tropsch fuel rendered dramatic reductions in soot emissions relative to operation on JP-8, due primarily to the lack of aromatic compounds in the alternative fuel. The Fischer-Tropsch fuel also produced smaller particles and slight reductions in CO emissions.

  15. A Facile Synthesis of SiO2@Co/mSiO2 Egg-Shell Nanoreactors for Fischer-Tropsch Reaction.

    PubMed

    Kwon, Jae In; Kim, Tae Wan; Park, Ji Chan; Yang, Jung-Il; Lee, Kwan Young

    2016-02-01

    Recently, a convenient melt-infiltration method, using a hydrated metal salt with porous support, was developed to prepare various metal/metal-oxide nanocatalysts. Until now, millimeter-scale, bead-shaped, cobalt egg-shell catalysts have been used to enhance the rate of reactant diffusion and catalyst performance. In the present work, new SiO2@Co/mSiO2 egg-shell nanoreactors (~300 nm) were synthesized with controlled Co content of 10 and 20 wt%. This was accomplished using a selective melt-infiltration process with porous silica shells around solid-silica cores. The SiO2@Co(10 wt%)/mSiO2 egg-shell catalyst that bears small cobalt nanoparticles of -2 nm was successfully employed for the industrially valuable Fischer-Tropsch synthesis reaction, showing the high activity of -8.0 x 10(-5) mol(CO) x gCo(-1) x S(-1).

  16. Monodisperse and size-tunable CoO nanocrystals synthesized by thermal decomposition and as an active precursor for Fischer-Tropsch synthesis

    NASA Astrophysics Data System (ADS)

    Lv, Shuai; Zhao, Xin; Xia, Guofu; Jin, Chao; Wang, Li; Yang, Weimin; Zhang, Yuhua; Li, Jinlin

    2017-01-01

    CoO nanocrystals with tunable particle sizes were prepared by thermal decomposition of cobalt(II) acetate in different long-chain alkyl amines. These alkyl amines strongly affect the coordination of the amine group to the metal atoms and the metal-amine interaction, thereby mediating the eventual particle sizes in the condensation process. Moreover, CoO nanocrystals were applied for synthesis of supported catalyst, and exhibited higher catalytic activity in Fischer-Tropsch reaction, demonstrating that nanocrystals are active precursor. The TOF of CO on CoAl-n catalyst obtained from CoO nanocrystals is ∼1.5 times higher than that on conventional catalyst with the same particle size.

  17. On-line gas chromatographic analysis of Fischer-Tropsch synthesis products formed in a supercritical reaction medium

    SciTech Connect

    Snavely, K.; Subramaniam, B.

    1997-10-01

    C{sub 1}-C{sub 30} products from Fischer-Tropsch synthesis, conducted in a supercritical n-hexane medium over an Fe catalyst in a fixed-bed reactor, are analyzed using on-line gas chromatography. A Hewlett-Packard 5890 Series II gas chromatograph (GC) is modified to minimize the effects of condensation of the on-line sample in the transfer lines. The GC is configured with a Supelco Petrocol DH capillary column connected to a flame ionization detector (FID) and two 1.83 m {times} 3.18 mm stainless steel columns placed in series, packed with 80/100 mesh HayeSep D, connected to a thermal conductivity detector (TCD). It is shown that pressure and temperature affect the elution order of oxygenates relative to hydrocarbons in the nonpolar capillary column. This phenomenon is exploited for obtaining improved resolution; several distinct methods produce similar elution orders. Ar, added to the syngas feed, is used to calculate syngas conversion. All compounds eluting before hexane (C{sub 1}-C{sub 5}, other than 2-methylpropene/1-butene and propanal/propanone) and nearly all the major peaks eluting after hexane are resolved in the capillary column. H{sub 2}, Ar, CO, CH{sub 4}, CO{sub 2}, and H{sub 2}O are resolved in the packed columns. The method provides excellent quantitative measurement of component mole fractions that are within the range of calibration.

  18. A chemical route to the formation of water in circumstellar envelopes around carbon-rich asymptotic branch stars: Fischer-Tropsch catalysis

    NASA Technical Reports Server (NTRS)

    Willacy, K.

    2004-01-01

    Fischer-Tropsch catalysis has been suggested as a means of driving hydrocarbon chemistry in oxygen rich regions such as the protosolar nebula. In addition to producing hydrocarbons, Fischer-Tropsch catalysis also produces water, and it is therefore possible that such processes could account for the recent observations of water in the circumstellar envelope of asymptotic giant branch star IRC +10216.

  19. Insight into CH4 formation and chain growth mechanism of Fischer-Tropsch synthesis on θ-Fe3C(0 3 1)

    NASA Astrophysics Data System (ADS)

    Wang, Yifan; Li, Ying; Huang, Shouying; Wang, Jian; Wang, Hongyu; Lv, Jing; Ma, Xinbin

    2017-08-01

    θ-Fe3C has been reported to play a key role in C2-C4 olefins production for Fischer-Tropsch synthesis. In this work, (0 3 1) is confirmed as the most exposed facet of θ-Fe3C due to its thermodynamic stability. Investigation on CH4 formation and C1-C1 coupling reveals that CH4 formation exhibits a high effective barrier and CH + CH and CH2 + CH2 are the dominant chain growth pathways. ΔEeff was employed to quantify the selectivity of CH4 and C2+. The high value of ΔEeff indicates the preference of C2+ formation to CH4. These results will help for the design of selective Fe-based FT catalysts.

  20. Straightforward synthesis of bimetallic Co/Pt nanoparticles in ionic liquid: atomic rearrangement driven by reduction-sulfidation processes and Fischer-Tropsch catalysis

    NASA Astrophysics Data System (ADS)

    Silva, Dagoberto O.; Luza, Leandro; Gual, Aitor; Baptista, Daniel L.; Bernardi, Fabiano; Zapata, Maximiliano J. M.; Morais, Jonder; Dupont, Jairton

    2014-07-01

    Unsupported bimetallic Co/Pt nanoparticles (NPs) of 4.4 +/- 1.9 nm can be easily obtained by a simple reaction of [bis(cylopentadienyl)cobalt(ii)] and [tris(dibenzylideneacetone) bisplatinum(0)] complexes in 1-n-butyl-3-methylimidazolium hexafluorophosphate IL at 150 °C under hydrogen (10 bar) for 24 h. These bimetallic NPs display core-shell like structures in which mainly Pt composes the external shell and its concentration decreases in the inner-shells (CoPt3@Pt-like structure). XPS and EXAFS analyses show the restructuration of the metal composition at the NP surface when they are subjected to hydrogen and posterior H2S sulfidation, thus inducing the migration of Co atoms to the external shells of the bimetallic NPs. Furthermore, the isolated bimetallic NPs are active catalysts for the Fischer-Tropsch synthesis, with selectivity for naphtha products.

  1. Comparison of hydrocracking Fischer-Tropsch wax with VGO hydrocracking and pure component mechanisms

    SciTech Connect

    Ekwall, G.R.; Yuh, E.; McArdle, J.C.; Steigleder, K.

    1987-01-01

    Hydrocracking pilot plant tests have been conducted on Fischer-Tropsch wax. Analytical results show that the feedstock is less complex than typical hydrocracking feedstocks, hence the test results can be used to gain understanding of the reaction mechanisms of hydrocracking normal paraffins. Data from process variable surveys changing pressure, combined feed ratio, liquid hourly space velocity and recycle hydrogen rate all support the carbonium ion mechanism of normal paraffin hydrocracking. The data show a consistent relationship between the degree of secondary vs. primary cracking proposed in the mechanism and product distribution.

  2. Thermal Stability Testing of Fischer-Tropsch Fuel and Various Blends with Jet A, as Well as Aromatic Blend Additives

    NASA Technical Reports Server (NTRS)

    Klettlinger, J.; Rich, R.; Yen, C.; Surgenor, A.

    2011-01-01

    Fischer-Tropsch (F-T) jet fuel composition differs from petroleum-based, conventional commercial jet fuel because of differences in feedstock and production methodology. Fischer-Tropsch fuel typically has a lower aromatic and sulfur content and consists primarily of iso and normal parafins. The ASTM D3241 specification for Jet Fuel Thermal Oxidation Test (JFTOT) break point testing method was used to test the breakpoint of a baseline conventional Jet A, a commercial grade F-T jet fuel, and various blends of this F-T fuel in Jet A. The testing completed in this report was supported by the NASA Fundamental Aeronautics Subsonics Fixed Wing Project.

  3. Fischer-Tropsch synthesis on functionalized carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Pokhrel, Sewa

    The aim of this research was to investigate the role of chemical functionalization on carbon nanotubes surfaces and its effect on FT catalysis. Multi walled carbon nanotubes (MWNT) were first treated with acid (HCl) to remove the residual metal particles and were then functionalized using H2O2 and HNO3 to introduce oxygen-containing groups to the MWNT surface. These treatments also add defects on MWNT surface. Morphological analyses were performed on the MWNT samples with TEM and it was found that the peroxide and acid treated MWNTs showed an increase oxygen functional groups and created additional surface defects on the MWNTs. Results of FT experiments showed enhanced CO conversion, FT activity and product selectivity towards liquid hydrocarbons due to functionalization. The liquid selectivity was found to be significantly high for H2O 2 treated catalyst. HNO3 treated catalyst had highest activity although selectivity to methane and CO2 was found higher than the H2O2 treated catalyst. It was observed that the chemical treatments increase the carbon chain length of the produced hydrocarbons. While comparing hydrocarbon distribution of as-produced and H2O2 treated MWNT, it was found that carbon-chain length increases for peroxide treated catalyst. Along with as-produced and functionalized nanotube, FT experiments were also conducted using B-doped sponge, un-doped sponge and N-doped CNT catalyst. B-doped sponge showed enhanced CO conversion and FT activity as compared to un-doped sponge. Conversion and product selectivity were found to be affected by temperature when test was conducted with N-CNT. Operating conditions like temperature, syngas feed flow rate and syngas ratio were also to impact the FT performance.

  4. Fischer Tropsch synthesis in supercritical fluids. Quarterly technical progress report, July 1, 1995--September 30, 1995

    SciTech Connect

    Akgerman, A.; Bukur, D.B.

    1996-05-01

    Our objective for this quarter was to compare performance of the Ruhrchemie catalyst in different modes of operation: fixed bed reactor (conventional and supercritical mode of operation), and stirred tank slurry reactor. Diffusion coefficients are discussed.

  5. Fischer-Tropsch fuel for use by the U.S. military as battlefield-use fuel of the future

    SciTech Connect

    Delanie Lamprecht

    2007-06-15

    The United States Department of Defense (DoD) has been interested in low-sulfur, environmentally cleaner Fischer-Tropsch (FT) fuels since 2001 because they want to be less dependent upon foreign crude oil and ensure the security of the supply. A three-phase Joint Battlefield-Use Fuel of the Future (BUFF) program was initiated to evaluate, demonstrate, certify, and implement turbine fuels produced from alternative energy resources for use in all of its gas turbine and diesel engine applications. Sasol Synfuels International (Pty) Ltd. and Sasol Chevron Holdings Ltd., among others, were invited to participate in the program with the objective to supply the DoD with a FT BUFF that conforms to Jet Propulsion 8 (JP-8) and JP-5 fuel volatility and low-temperature fluidity requirements. Although the DoD is more interested in coal-to-liquid (CTL) technology, the product from a gas-to-liquid (GTL) Products Work-Up Demonstration Unit in Sasolburg, South Africa, was used to evaluate (on a bench scale) the possibility of producing a BUFF fraction from the Sasol Slurry Phase Distillate (Sasol SPD) low-temperature FT (LTFT) process and Chevron Isocracking technology. It was concluded from the study that the production of a synthetic FT BUFF is feasible using the Sasol SPD LTFT technology together with the current Chevron isocracking technology. The product yield for a BUFF conforming to JP-8 requirements is 30 vol % of the fractionator feed, whereas the product yield for a BUFF conforming to the JP-5 volatility requirement is slightly less than 22 vol % of the fractionator feed. Also concluded from the study was that the end point of the Sasol SPD LTFT BUFF will be restricted by the freezing point requirement of the DoD and not the maximum viscosity requirement. One would therefore need to optimize the hydrocracking process conditions to increase the Sasol SPD LTFT BUFF product yield. 16 refs., 8 figs., 6 tabs.

  6. 40 CFR 721.10103 - Naphtha (Fischer-Tropsch), C4-11-alkane, branched and linear.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-alkane, branched and linear. 721.10103 Section 721.10103 Protection of Environment ENVIRONMENTAL..., branched and linear. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as naphtha (fischer-tropsch), C4-11-alkane, branched and linear (PMN P-04-235; CAS...

  7. 40 CFR 721.10103 - Naphtha (Fischer-Tropsch), C4-11-alkane, branched and linear.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-alkane, branched and linear. 721.10103 Section 721.10103 Protection of Environment ENVIRONMENTAL..., branched and linear. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as naphtha (fischer-tropsch), C4-11-alkane, branched and linear (PMN P-04-235; CAS...

  8. 40 CFR 721.10103 - Naphtha (Fischer-Tropsch), C4-11-alkane, branched and linear.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-alkane, branched and linear. 721.10103 Section 721.10103 Protection of Environment ENVIRONMENTAL..., branched and linear. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as naphtha (fischer-tropsch), C4-11-alkane, branched and linear (PMN P-04-235; CAS...

  9. Carbon Isotopic Fractionation in Fischer-Tropsch Type Reactions and Relevance to Meteorite Organics

    NASA Technical Reports Server (NTRS)

    Johnson, Natasha M; Elsila, Jamie E.; Kopstein, Mickey; Nuth, Joseph A., III

    2012-01-01

    Fischer-Tropsch-Type (FTT) reactions have been hypothesized to contribute to the formation of organic compounds in the early solar system, but it has been difficult to identify a signature of such reactions in meteoritic organics. The work reported here examined whether temperature-dependent carbon isotopic fractionation of FTT reactions might provide such a signature. Analyses of bulk organic deposits resulting from FTT experiments show a slight trend towards lighter carbon isotopic ratios with increasing temperature. It is unlikely, however, that these carbon isotopic signatures could provide definitive provenance for organic compounds in solar system materials produced through FTT reactions, because of the small scale of the observed fractionations and the possibility that signatures from many different temperatures may be present in any specific grain.

  10. Optimisation of the Fischer-Tropsch process using zeolites for tail gas separation.

    PubMed

    Perez-Carbajo, J; Gómez-Álvarez, P; Bueno-Perez, R; Merkling, P J; Calero, S

    2014-03-28

    This work is aimed at optimizing a Fischer-Tropsch Gas To Liquid (GTL) process by recycling compounds of the expelled gas mixture using zeolites for the separation. To that end, we have performed a computational study on four structures widely used in industry. A range of Si/Al ratios have been explored and the effects of their distribution assessed. The ability of the considered force fields and molecular models to reproduce experimental results has been widely proved in previously reported studies. Since this tail gas is formed by a five-component mixture, namely carbon dioxide, methane, carbon monoxide, nitrogen and hydrogen, molecular simulations present clear advantages over experiments. In addition, the viability of the Ideal Adsorption Solution Theory (IAST) has been evaluated to easily handle further separation steps. On the basis of the obtained results, we provide a separation scheme to perform sequentially the separation of CO2, CH4, CO, N2 and H2.

  11. F-T process using an iron on mixed zirconia-titania supported catalyst

    DOEpatents

    Dyer, Paul N.; Nordquist, Andrew F.; Pierantozzi, Ronald

    1987-01-01

    A Fischer-Tropsch catalyst comprising iron co-deposited with or deposited on particles comprising a mixture of zirconia and titania, preferably formed by co-precipitation of compounds convertible to zirconia and titania, such as zirconium and titanium alkoxide. The invention also comprises the method of making this catalyst and an improved Fischer-Tropsch reaction process in which the catalyst is utilized.

  12. Techno-economic assessment of integrating methanol or Fischer-Tropsch synthesis in a South African sugar mill.

    PubMed

    Petersen, Abdul M; Farzad, Somayeh; Görgens, Johann F

    2015-05-01

    This study considered an average-sized sugar mill in South Africa that crushes 300 wet tonnes per hour of cane, as a host for integrating methanol and Fischer-Tropsch synthesis, through gasification of a combined flow of sugarcane trash and bagasse. Initially, it was shown that the conversion of biomass to syngas is preferably done by catalytic allothermal gasification instead of catalytic autothermal gasification. Thereafter, conventional and advanced synthesis routes for both Methanol and Fischer-Tropsch products were simulated with Aspen Plus® software and compared by technical and economic feasibility. Advanced FT synthesis satisfied the overall energy demands, but was not economically viable for a private investment. Advanced methanol synthesis is also not viable for private investment since the internal rate of return was 21.1%, because it could not provide the steam that the sugar mill required. The conventional synthesis routes had less viability than the corresponding advanced synthesis routes.

  13. Metal-carbon nanosystem IR-PVA/Fe-Co for catalysis in the Fischer-Tropsch synthesis

    NASA Astrophysics Data System (ADS)

    Vasilev, A. A.; Dzidziguri, E. L.; Ivantsov, M. I.; Efimov, M. N.

    2016-08-01

    Metal-carbon nanosystems consisting of nanodimensional bimetallic particles of Fe- Co dispersed in a carbon matrix for the Fischer-Tropsch synthesis were studied. Prepared metal-carbon nanopowders samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). It was shown formation of FeCo nanoparticles with body-centered cubic structures started at 400 °C. FeCo nanoparticles have spherical form, the mean size is 7 - 12 nm and uniform distribution in a carbon matrix. The metal-carbon nanosystem demonstrates a catalytic activity in the Fischer- Tropsch synthesis. The maximum yield of liquid hydrocabons C5+ was 92 g/m3 while the selectivity for the target product - 35%.

  14. Production of High Molecular Weight Organic Compounds on the Surfaces of Amorphous Iron Silicate Catalysts: Implications for Organic Synthesis in the Solar Nebula

    NASA Technical Reports Server (NTRS)

    Gilmour, I.; Hill, H. G. M.; Pearson, V. K.; Sephton, M. A.; Nuth, J. A., III

    2002-01-01

    The high molecular weight organic products of Fischer-Tropsch/Haber-Bosch syntheses on the surfaces of Fe-silicate catalysts have been studied by GCMS. Additional information is contained in the original extended abstract.

  15. Production of High Molecular Weight Organic Compounds on the Surfaces of Amorphous Iron Silicate Catalysts: Implications for Organic Synthesis in the Solar Nebula

    NASA Technical Reports Server (NTRS)

    Gilmour, I.; Hill, H. G. M.; Pearson, V. K.; Sephton, M. A.; Nuth, J. A., III

    2002-01-01

    The high molecular weight organic products of Fischer-Tropsch/Haber-Bosch syntheses on the surfaces of Fe-silicate catalysts have been studied by GCMS. Additional information is contained in the original extended abstract.

  16. Incorporation of catalytic dehydrogenation into Fischer-Tropsch synthesis to lower carbon dioxide emissions

    DOEpatents

    Huffman, Gerald P

    2012-09-18

    A method for producing liquid fuels includes the steps of gasifying a starting material selected from a group consisting of coal, biomass, carbon nanotubes and mixtures thereof to produce a syngas, subjecting that syngas to Fischer-Tropsch synthesis (FTS) to produce a hyrdrocarbon product stream, separating that hydrocarbon product stream into C1-C4 hydrocarbons and C5+ hydrocarbons to be used as liquid fuels and subjecting the C1-C4 hydrocarbons to catalytic dehydrogenation (CDH) to produce hydrogen and carbon nanotubes. The hydrogen produced by CDH is recycled to be mixed with the syngas incident to the FTS reactor in order to raise the hydrogen to carbon monoxide ratio of the syngas to values of 2 or higher, which is required to produce liquid hydrocarbon fuels. This is accomplished with little or no production of carbon dioxide, a greenhouse gas. The carbon is captured in the form of a potentially valuable by-product, multi-walled carbon nanotubes (MWNT), while huge emissions of carbon dioxide are avoided and very large quantities of water employed for the water-gas shift in traditional FTS systems are saved.

  17. Lipid Synthesis Under Hydrothermal Conditions by Fischer- Tropsch-Type Reactions

    NASA Astrophysics Data System (ADS)

    McCollom, Thomas M.; Ritter, Gilles; Simoneit, Bernd R. T.

    1999-03-01

    Ever since their discovery in the late 1970's, mid-ocean-ridge hydrothermal systems have received a great deal of attention as a possible site for the origin of life on Earth (and environments analogous to mid-ocean-ridge hydrothermal systems are postulated to have been sites where life could have originated on Mars and elsewhere as well). Because no modern-day terrestrial hydrothermal systems are free from the influence of organic compounds derived from biologic processes, laboratory experiments provide the best opportunity for confirmation of the potential for organic synthesis in hydrothermal systems. Here we report on the formation of lipid compounds during Fischer-Tropsch-type synthesis from aqueous solutions of formic acid or oxalic acid. Optimum synthesis occurs in stainless steel vessels by heating at 175 °C for 2-3 days and produces lipid compounds ranging from C2 to >C35 which consist of n-alkanols, n- alkanoic acids, n-alkenes, n-alkanes and alkanones. The precursor carbon sources used are either formic acid or oxalic acid, which disproportionate to H2, CO2 and probably CO. Both carbon sources yield the same lipid classes with essentially the same ranges of compounds. The synthesis reactions were confirmed by using 13C labeled precursor acids.

  18. ULTRA-CLEAN FISCHER-TROPSCH FUELS PRODUCTION AND DEMONSTRATION PROJECT

    SciTech Connect

    Steve Bergin

    2003-10-17

    The Syntroleum plant is mechanically complete and currently undergoing start-up. The fuel production and demonstration plan is near completion. The study on the impact of small footprint plant (SFP) fuel on engine performance is about half-completed. Cold start testing has been completed. Preparations have been completed for testing the fuel in diesel electric generators in Alaska. Preparations are in progress for testing the fuel in bus fleets at Denali National Park and the Washington Metropolitan Transit Authority. The experiments and analyses conducted during this project show that Fischer-Tropsch (FT) gas-to-liquid diesel fuel can easily be used in a diesel engine with little to no modifications. Additionally, based on the results and discussion presented, further improvements in performance and emissions can be realized by configuring the engine to take advantage of FT diesel fuel's properties. The FT fuel also shows excellent cold start properties and enabled the engine tested to start at more the ten degrees than traditional fuels would allow. This plant produced through this project will produce large amounts of FT fuel. This will allow the fuel to be tested extensively, in current, prototype, and advanced diesel engines. The fuel may also contribute to the nation's energy security. The military has expressed interest in testing the fuel in aircraft and ground vehicles.

  19. Lipid synthesis under hydrothermal conditions by Fischer-Tropsch-type reactions.

    PubMed

    McCollom, T M; Ritter, G; Simoneit, B R

    1999-03-01

    Ever since their discovery in the late 1970's, mid-ocean-ridge hydrothermal systems have received a great deal of attention as a possible site for the origin of life on Earth (and environments analogous to mid-ocean-ridge hydrothermal systems are postulated to have been sites where life could have originated or Mars and elsewhere as well). Because no modern-day terrestrial hydrothermal systems are free from the influence of organic compounds derived from biologic processes, laboratory experiments provide the best opportunity for confirmation of the potential for organic synthesis in hydrothermal systems. Here we report on the formation of lipid compounds during Fischer-Tropsch-type synthesis from aqueous solutions of formic acid or oxalic acid. Optimum synthesis occurs in stainless steel vessels by heating at 175 degrees C for 2-3 days and produces lipid compounds ranging from C2 to > C35 which consist of n-alkanols, n-alkanoic acids, n-alkenes, n-alkanes and alkanones. The precursor carbon sources used are either formic acid or oxalic acid, which disproportionate to H2, CO2 and probably CO. Both carbon sources yield the same lipid classes with essentially the same ranges of compounds. The synthesis reactions were confirmed by using 13C labeled precursor acids.

  20. Fischer-Tropsch synthesis on hierarchically structured cobalt nanoparticle/carbon nanofiber/carbon felt composites.

    PubMed

    Zarubova, Sarka; Rane, Shreyas; Yang, Jia; Yu, Yingda; Zhu, Ye; Chen, De; Holmen, Anders

    2011-07-18

    The hierarchically structured carbon nanofibers (CNFs)/carbon felt composites, in which CNFs were directly grown on the surface of microfibers in carbon felt, forming a CNF layer on a micrometer range that completely covers the microfiber surfaces, were tested as a novel support material for cobalt nanoparticles in the highly exothermic Fischer-Tropsch (F-T) synthesis. A compact, fixed-bed reactor, made of disks of such composite materials, offered the advantages of improved heat and mass transfer, relatively low pressure drop, and safe handling of immobilized CNFs. An efficient 3-D thermal conductive network in the composite provided a relatively uniform temperature profile, whereas the open structure of the CNF layer afforded an almost 100 % effectiveness of Co nanoparticles in the F-T synthesis in the fixed bed. The greatly improved mass and heat transport makes the compact reactor attractive for applications in the conversion of biomass, coal, and natural gas to liquids. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Thermal Stability Results of a Fischer-Tropsch Fuel With Various Blends of Aromatic Solution

    NASA Technical Reports Server (NTRS)

    Lindsey, Jennifer; Klettlinger, Suder

    2013-01-01

    Fischer-Tropsch (F-T) jet fuel composition differs from petroleum-based, conventional commercial jet fuel because of differences in feedstock and production methodology. F-T fuel typically has a lower aromatic and sulfur content and consists primarily of iso and normal paraffins. The ASTM D3241 specification for Jet Fuel Thermal Oxidation Test (JFTOT) break point testing method was used to test the breakpoint of a baseline commercial grade F-T jet fuel, and various blends of this F-T fuel with an aromatic solution. The goal of this research is to determine the effect of aromatic content on the thermal stability of F-T fuel. The testing completed in this report was supported by the NASA Fundamental Aeronautics Subsonic Fixed Wing Project. Two different aromatic content fuels from Rentech, as well as these fuels with added aromatic blend were analyzed for thermal stability using the JFTOT method. Preliminary results indicate a reduction in thermal stability occurs upon increasing the aromatic content to 10% by adding an aromatic blend to the neat fuel. These results do not specify a failure based on pressure drop, but only on tube color. It is unclear whether tube color correlates to more deposition on the tube surface or not. Further research is necessary in order to determine if these failures are true failures based on tube color. Research using ellipsometry to determine tube deposit thickness rather than color will be continued in follow-up of this study.

  2. Lipid synthesis under hydrothermal conditions by Fischer-Tropsch-type reactions

    NASA Technical Reports Server (NTRS)

    McCollom, T. M.; Ritter, G.; Simoneit, B. R.

    1999-01-01

    Ever since their discovery in the late 1970's, mid-ocean-ridge hydrothermal systems have received a great deal of attention as a possible site for the origin of life on Earth (and environments analogous to mid-ocean-ridge hydrothermal systems are postulated to have been sites where life could have originated or Mars and elsewhere as well). Because no modern-day terrestrial hydrothermal systems are free from the influence of organic compounds derived from biologic processes, laboratory experiments provide the best opportunity for confirmation of the potential for organic synthesis in hydrothermal systems. Here we report on the formation of lipid compounds during Fischer-Tropsch-type synthesis from aqueous solutions of formic acid or oxalic acid. Optimum synthesis occurs in stainless steel vessels by heating at 175 degrees C for 2-3 days and produces lipid compounds ranging from C2 to > C35 which consist of n-alkanols, n-alkanoic acids, n-alkenes, n-alkanes and alkanones. The precursor carbon sources used are either formic acid or oxalic acid, which disproportionate to H2, CO2 and probably CO. Both carbon sources yield the same lipid classes with essentially the same ranges of compounds. The synthesis reactions were confirmed by using 13C labeled precursor acids.

  3. Gaseous product mixture from Fischer-Tropsch synthesis as an efficient carbon feedstock for low temperature CVD growth of carbon nanotube carpets

    NASA Astrophysics Data System (ADS)

    Almkhelfe, Haider; Carpena-Núñez, Jennifer; Back, Tyson C.; Amama, Placidus B.

    2016-07-01

    Low-temperature chemical vapor deposition (CVD) growth of carbon nanotube (CNT) carpets from Fe and Fe-Cu catalysts using a gaseous product mixture from Fischer-Tropsch synthesis (FTS-GP) as a superior carbon feedstock is demonstrated. This growth approach addresses a persistent issue of obtaining thick CNT carpets on temperature-sensitive substrates at low temperatures using a non-plasma CVD approach without catalyst pretreatment and/or preheating of the carbon feedstock. The efficiency of the process is evidenced by the highly dense, vertically aligned CNT structures from both Fe and Fe-Cu catalysts even at temperatures as low as 400 °C - a record low growth temperature for CNT carpets obtained via conventional thermal CVD. The grown CNTs exhibit a straight morphology with hollow interior and parallel graphitic planes along the tube walls. The apparent activation energies for CNT carpet growth on Fe and Fe-Cu catalysts are 0.71 and 0.54 eV, respectively. The synergistic effect of Fe and Cu show a strong dependence on the growth temperature, with Cu being more influential at temperatures higher than 450 °C. The low activation energies and long catalyst lifetimes observed are rationalized based on the unique composition of FTS-GP and Gibbs free energies for the decomposition reactions of the hydrocarbon components. The use of FTS-GP facilitates low-temperature growth of CNT carpets on traditional (alumina film) and nontraditional substrates (aluminum foil) and has the potential of enhancing CNT quality, catalyst lifetime, and scalability.Low-temperature chemical vapor deposition (CVD) growth of carbon nanotube (CNT) carpets from Fe and Fe-Cu catalysts using a gaseous product mixture from Fischer-Tropsch synthesis (FTS-GP) as a superior carbon feedstock is demonstrated. This growth approach addresses a persistent issue of obtaining thick CNT carpets on temperature-sensitive substrates at low temperatures using a non-plasma CVD approach without catalyst

  4. Efficient utilization of greenhouse gases in a gas-to-liquids process combined with CO2/steam-mixed reforming and Fe-based Fischer-Tropsch synthesis.

    PubMed

    Zhang, Chundong; Jun, Ki-Won; Ha, Kyoung-Su; Lee, Yun-Jo; Kang, Seok Chang

    2014-07-15

    Two process models for carbon dioxide utilized gas-to-liquids (GTL) process (CUGP) mainly producing light olefins and Fischer-Tropsch (F-T) synthetic oils were developed by Aspen Plus software. Both models are mainly composed of a reforming unit, an F-T synthesis unit and a recycle unit, while the main difference is the feeding point of fresh CO2. In the reforming unit, CO2 reforming and steam reforming of methane are combined together to produce syngas in flexible composition. Meanwhile, CO2 hydrogenation is conducted via reverse water gas shift on the Fe-based catalysts in the F-T synthesis unit to produce hydrocarbons. After F-T synthesis, the unreacted syngas is recycled to F-T synthesis and reforming units to enhance process efficiency. From the simulation results, it was found that the carbon efficiencies of both CUGP options were successfully improved, and total CO2 emissions were significantly reduced, compared with the conventional GTL processes. The process efficiency was sensitive to recycle ratio and more recycle seemed to be beneficial for improving process efficiency and reducing CO2 emission. However, the process efficiency was rather insensitive to split ratio (recycle to reforming unit/total recycle), and the optimum split ratio was determined to be zero.

  5. Impact of Hydrogenolysis on the Selectivity of the Fischer-Tropsch Synthesis: Diesel Fuel Production over Mesoporous Zeolite-Y-Supported Cobalt Nanoparticles.

    PubMed

    Peng, Xiaobo; Cheng, Kang; Kang, Jincan; Gu, Bang; Yu, Xiang; Zhang, Qinghong; Wang, Ye

    2015-04-07

    Selectivity control is a challenging goal in Fischer-Tropsch (FT) synthesis. Hydrogenolysis is known to occur during FT synthesis, but its impact on product selectivity has been overlooked. Demonstrated herein is that effective control of hydrogenolysis by using mesoporous zeolite Y-supported cobalt nanoparticles can enhance the diesel fuel selectivity while keeping methane selectivity low. The sizes of the cobalt particles and mesopores are key factors which determine the selectivity both in FT synthesis and in hydrogenolysis of n-hexadecane, a model compound of heavier hydrocarbons. The diesel fuel selectivity in FT synthesis can reach 60 % with a CH4 selectivity of 5 % over a Na-type mesoporous Y-supported cobalt catalyst with medium mean sizes of 8.4 nm (Co particles) and 15 nm (mesopores). These findings offer a new strategy to tune the product selectivity and possible interpretations of the effect of cobalt particle size and the effect of support pore size in FT synthesis.

  6. New approach to the generation of metal-bearing, medium-pore, shape-selective zeolites for Fischer-Tropsch catalysis. Spectroscopic studies of zeolites

    SciTech Connect

    Iton, L.E.; Beal, R.B.; Hodul, D.T.

    1983-01-01

    Two recent developments in zeolite synthesis and modification were successfully combined to demonstrate a new approach to the generation of metal-bearing, medium-pore, shape-selective zeolites for use as catalysts in Fischer-Tropsch conversions. The steps are: (1) synthesis of an aluminoferrisilicate zeolite having the ZSM-5-type structure; (2) removal of the organic base template incorporated in the channel system during synthesis; (3) formation of a polycyano inclusion compound in the AFS zeolite; and (4) reduction of the inclusion compound by hydrogen at approx. 400/sup 0/C. PAS and EPR spectroscopy have been used to establish that the as-synthesized AFS zeolite contains Fe/sup 3 +/ ions in both framework and non-framework sites. FMR spectroscopy has been used to confirm the formation of the metallic (Fe) and bimetallic (Fe/Ru and Fe/Co) particles as products of the reduction of the inclusion compounds by hydrogen. The application of other spectroscopic techniques in recent studies of cations, complexes, and metal particles in zeolites is reviewed: high-resolution solid-state NMR, nuclear-spin-relaxation studies, FMR, EXAFS, and XANES.

  7. Aspen Process Flowsheet Simulation Model of a Battelle Biomass-Based Gasification, Fischer-Tropsch Liquefaction and Combined-Cycle Power Plant

    SciTech Connect

    1998-10-30

    This study was done to support the research and development program of the National Renewable Energy Laboratory (NREL) in the thermochemical conversion of biomass to liquid transportation fuels using current state-of-the-art technology. The Mitretek study investigated the use of two biomass gasifiers; the RENUGAS gasifier being developed by the Institute of Gas Technology, and the indirectly heated gasifier being developed by Battelle Columbus. The Battelle Memorial Institute of Columbus, Ohio indirectly heated biomass gasifier was selected for this model development because the syngas produced by it is better suited for Fischer-Tropsch synthesis with an iron-based catalyst for which a large amount of experimental data are available. Bechtel with Amoco as a subcontractor developed a conceptual baseline design and several alternative designs for indirect coal liquefaction facilities. In addition, ASPEN Plus process flowsheet simulation models were developed for each of designs. These models were used to perform several parametric studies to investigate various alternatives for improving the economics of indirect coal liquefaction.

  8. Slurry phase iron catalysts for indirect coal liquefaction. Second semi-annual progress report, January 5, 1996--July 4, 1996

    SciTech Connect

    Datye, A.K.

    1996-08-02

    During this period, work was continued on understanding the attrition of precipitated iron catalysts and work initiated on synthesizing catalysts containing silica binders. Use of a sedigraph particle size analyzer with an ultrasonic probe provides a simple method to test the strength of catalyst agglomerates, allowing the strength comparison of silica and hematite catalysts (the former is considerably stronger). Study of Fe/silica interactions was continued. Addition of a colloidal silica precursor to calcined Fe{sub 2}O{sub 3} catalyst had no detrimental effect on reducibility of the hematite to {alpha}-Fe. XRD and electron microscopy will be used to analyze the crystal structure and types of C present in samples from long Fischer-Tropsch runs.

  9. Effect of the Polymeric Stabilizer in the Aqueous Phase Fischer-Tropsch Synthesis Catalyzed by Colloidal Cobalt Nanocatalysts

    PubMed Central

    Delgado, Jorge A.; Claver, Carmen; Castillón, Sergio; Curulla-Ferré, Daniel; Godard, Cyril

    2017-01-01

    A series of small and well defined cobalt nanoparticles were synthesized by the chemical reduction of cobalt salts in water using NaBH4 as a reducing agent and using various polymeric stabilizers. The obtained nanocatalysts of similar mean diameters (ca. 2.6 nm) were fully characterized and tested in the aqueous phase Fischer-Tropsch Synthesis (AFTS). Interestingly, the nature and structure of the stabilizers used during the synthesis of the CoNPs affected the reduction degree of cobalt and the B-doping of these NPs and consequently, influenced the performance of these nanocatalysts in AFTS. PMID:28336892

  10. Effect of the Polymeric Stabilizer in the Aqueous Phase Fischer-Tropsch Synthesis Catalyzed by Colloidal Cobalt Nanocatalysts.

    PubMed

    Delgado, Jorge A; Claver, Carmen; Castillón, Sergio; Curulla-Ferré, Daniel; Godard, Cyril

    2017-03-06

    A series of small and well defined cobalt nanoparticles were synthesized by the chemical reduction of cobalt salts in water using NaBH4 as a reducing agent and using various polymeric stabilizers. The obtained nanocatalysts of similar mean diameters (ca. 2.6 nm) were fully characterized and tested in the aqueous phase Fischer-Tropsch Synthesis (AFTS). Interestingly, the nature and structure of the stabilizers used during the synthesis of the CoNPs affected the reduction degree of cobalt and the B-doping of these NPs and consequently, influenced the performance of these nanocatalysts in AFTS.

  11. Organic Analysis of Catalytic Fischer-Tropsch Synthesis Products and Ordinary Chondrite Meteorites by Stepwise Pyrolysis-GCMS: Organics in the Early Solar Nebula

    NASA Technical Reports Server (NTRS)

    Locke, Darren R.; Yazzie, Cyriah A.; Burton, Aaron S.; Niles, Paul B.; Johnson, Natasha M.

    2014-01-01

    Abiotic generation of complex organic compounds, in the early solar nebula that formed our solar system, is hypothesized by some to occur via Fischer-Tropsch (FT) synthesis. In its simplest form, FT synthesis involves the low temperature (<300degC) catalytic reaction of hydrogen and carbon monoxide gases to form more complex hydrocarbon compounds, primarily n-alkanes, via reactive nano-particulate iron, nickel, or cobalt, for example. Industrially, this type of synthesis has been utilized in the gas-to-liquid process to convert syngas, produced from coal, natural gas, or biomass, into paraffin waxes that can be cracked to produce liquid diesel fuels. In general, the effect of increasing reaction temperature (>300degC) produces FT products that include lesser amounts of n-alkanes and greater alkene, alcohol, and polycyclic aromatic hydrocarbon (PAH) compounds. We have begun to experimentally investigate FT synthesis in the context of abiotic generation of organic compounds in the early solar nebula. It is generally thought that the early solar nebula included abundant hydrogen and carbon monoxide gases and nano-particulate matter such as iron and metal silicates that could have catalyzed the FT reaction. The effect of FT reaction temperature, catalyst type, and experiment duration on the resulting products is being investigated. These solid organic products are analyzed by thermal-stepwise pyrolysis-GCMS and yield the types and distribution of hydrocarbon compounds released as a function of temperature. We show how the FT products vary by reaction temperature, catalyst type, and experimental duration and compare these products to organic compounds found to be indigenous to ordinary chondrite meteorites. We hypothesize that the origin of organics in some chondritic meteorites, that represent an aggregation of materials from the early solar system, may at least in part be from FT synthesis that occurred in the early solar nebula.

  12. Ab initio study of key branching reactions in biodiesel and Fischer-Tropsch fuels.

    PubMed

    Davis, Alexander C; Francisco, Joseph S

    2011-11-30

    Many biologically and Fischer-Tropsch synthesized fuels contain branched alkanes which, during their combustion and atmospheric oxidation mechanism, produce methylalkyl radicals. As a result, an accurate description of the chemistry of these species is essential to integrating these fuels into our energy systems. Even though branched alkanes make up roughly one-third of the compounds in gasoline and diesel fuels, both experimental and theoretical data on methylalkyl radicals and their reactions are scarce, especially for larger chain systems and combustion conditions. The present work investigates all the hydrogen migration reactions available to the n-methylprop-1-yl through n-methylhept-1-yl radicals, for n = 2-6, using the CBS-Q, G2, and G4 composite computational methods, over a wide temperature range. The resulting thermodynamic and kinetic parameters are used to determine the effect that the presence of the methyl group has on these important unimolecular, chain branching reactions, for the reactions involving not only a tertiary abstraction site but also all the primary and secondary sites. The activation energies of hydrogen migration reactions with the methyl group, either within or immediately outside the ring, are found to be roughly 0.8-1.6 kcal mol(-1) lower in energy than expected on the basis of analogous reactions in n-alkyl radicals. An important implication of this result is that the current method of using rate parameters derived from n-alkyl radicals to predict the chain branching characteristics of methylated alkyl radicals significantly underpredicts the importance of these reactions in atmospheric and combustion processes. Discussion of a possible cause for this phenomenon and its effect on the overall combustion mechanism of branched hydrocarbons is presented. Of particular concern is that 2,2,4,4,6,8,8-heptamethylnonane, which is currently used to model branched alkanes in diesel fuel surrogates, is predicted to have a much lower activation

  13. Stoichiometric and catalytic homologation of olefins on the Fischer-Tropsch catalysts Fe/SiO/sub 2/, Ru/SiO/sub 2/, Os/SiO/sup 2/, and Rh/SiO/sub 2/. Mechanistic implication in the mode of C-C bond formation

    SciTech Connect

    Leconte, M.; Theolier, A.; Rojas, D.; Basset, J.M.

    1984-02-22

    The formation of C/sub 4/ olefinic hydrocarbons both in CO + H/sub 2/ and C/sub 3/H/sub 6/ + H/sub 2/ reactions has been studied to test the assumption that the same mechanism is involved in the C-C bond formation in syn gas conversion and olefin hydrogenation. The yields of linear and branched olefins were measured at various contact times, and initial selectivities were obtained by extrapolation to zero conversion. The catalyst systems studied for the reactions were Fe, Ru, Rh, and Os supported by SiO/sub 2/. The results indicated that the same mechanism was involved in the C-C bond formation starting from CO + H/sub 2/, CH/sub 2/N/sub 2/ + H/sub 2/, or C/sub n/ H/sub 2n/ + H/sub 2/, and the mode of the C-C bond formation was shown to involve the addition of a C/sub 1/ fragment to a C/sub n/ fragment.

  14. Technology development for iron Fischer-Tropsch catalysts, September 30, 1991

    SciTech Connect

    Davis, B.H.

    1991-01-01

    Although the oxidation process of Fe(OH){sub 2} and the mechanism of formation of {gamma}-FeOOH have been studied by several groups, many questions still need to be answered. In addition, the procedure for the synthesis of pure {gamma}-FeOOH has not been well defined. This study is to an attempt to define better the chemistry associated with oxidizing Fe{sup 2+} to {gamma}-FeOOH, and to provide a rationale for scaling this method up to produce kg/hr amounts of {gamma}-FeOOH.

  15. Reductions in aircraft particulate emissions due to the use of Fischer-Tropsch fuels

    NASA Astrophysics Data System (ADS)

    Beyersdorf, A. J.; Timko, M. T.; Ziemba, L. D.; Bulzan, D.; Corporan, E.; Herndon, S. C.; Howard, R.; Miake-Lye, R.; Thornhill, K. L.; Winstead, E.; Wey, C.; Yu, Z.; Anderson, B. E.

    2013-06-01

    The use of alternative fuels for aviation is likely to increase due to concerns over fuel security, price stability and the sustainability of fuel sources. Concurrent reductions in particulate emissions from these alternative fuels are expected because of changes in fuel composition including reduced sulfur and aromatic content. The NASA Alternative Aviation Fuel Experiment (AAFEX) was conducted in January-February 2009 to investigate the effects of synthetic fuels on gas-phase and particulate emissions. Standard petroleum JP-8 fuel, pure synthetic fuels produced from natural gas and coal feedstocks using the Fischer-Tropsch (FT) process, and 50% blends of both fuels were tested in the CFM-56 engines on a DC-8 aircraft. To examine plume chemistry and particle evolution with time, samples were drawn from inlet probes positioned 1, 30, and 145 m downstream of the aircraft engines. No significant alteration to engine performance was measured when burning the alternative fuels. However, leaks in the aircraft fuel system were detected when operated with the pure FT fuels as a result of the absence of aromatic compounds in the fuel. Dramatic reductions in soot emissions were measured for both the pure FT fuels (reductions of 84% averaged over all powers) and blended fuels (64%) relative to the JP-8 baseline with the largest reductions at idle conditions. The alternative fuels also produced smaller soot (e.g. at 85% power, volume mean diameters were reduced from 78 nm for JP-8 to 51 nm for the FT fuel), which may reduce their ability to act as cloud condensation nuclei (CCN). The reductions in particulate emissions are expected for all alternative fuels with similar reductions in fuel sulfur and aromatic content regardless of the feedstock. As the plume cools downwind of the engine, nucleation-mode aerosols form. For the pure FT fuels, reductions (94% averaged over all powers) in downwind particle number emissions were similar to those measured at the exhaust plane (84

  16. Wabash Valley Integrated Gasification Combined Cycle, Coal to Fischer Tropsch Jet Fuel Conversion Study

    SciTech Connect

    Shah, Jayesh; Hess, Fernando; Horzen, Wessel van; Williams, Daniel; Peevor, Andy; Dyer, Andy; Frankel, Louis

    2016-06-01

    This reports examines the feasibility of converting the existing Wabash Integrated Gasification Combined Cycle (IGCC) plant into a liquid fuel facility, with the goal of maximizing jet fuel production. The fuels produced are required to be in compliance with Section 526 of the Energy Independence and Security Act of 2007 (EISA 2007 §526) lifecycle greenhouse gas (GHG) emissions requirements, so lifecycle GHG emissions from the fuel must be equal to or better than conventional fuels. Retrofitting an existing gasification facility reduces the technical risk and capital costs associated with a coal to liquids project, leading to a higher probability of implementation and more competitive liquid fuel prices. The existing combustion turbine will continue to operate on low cost natural gas and low carbon fuel gas from the gasification facility. The gasification technology utilized at Wabash is the E-Gas™ Technology and has been in commercial operation since 1995. In order to minimize capital costs, the study maximizes reuse of existing equipment with minimal modifications. Plant data and process models were used to develop process data for downstream units. Process modeling was utilized for the syngas conditioning, acid gas removal, CO2 compression and utility units. Syngas conversion to Fischer Tropsch (FT) liquids and upgrading of the liquids was modeled and designed by Johnson Matthey Davy Technologies (JM Davy). In order to maintain the GHG emission profile below that of conventional fuels, the CO2 from the process must be captured and exported for sequestration or enhanced oil recovery. In addition the power utilized for the plant’s auxiliary loads had to be supplied by a low carbon fuel source. Since the process produces a fuel gas with sufficient energy content to power the plant’s loads, this fuel gas was converted to hydrogen and exported to the existing gas turbine for low carbon power production. Utilizing low carbon fuel gas and

  17. Ultra-clean Fischer-Tropsch (F-T) Fuels Production and Demonstration Project

    SciTech Connect

    Stephen P. Bergin

    2006-06-30

    The objective of the DOE-NETL Fischer-Tropsch (F-T) Production and Demonstration Program was to produce and evaluate F-T fuel derived from domestic natural gas. The project had two primary phases: (1) fuel production of ultra-clean diesel transportation fuels from domestic fossil resources; and (2) demonstration and performance testing of these fuels in engines. The project also included a well-to-wheels economic analysis and a feasibility study of small-footprint F-T plants (SFPs) for remote locations such as rural Alaska. During the fuel production phase, ICRC partnered and cost-shared with Syntroleum Corporation to complete the mechanical design, construction, and operation of a modular SFP that converts natural gas, via F-T and hydro-processing reactions, into hydrogensaturated diesel fuel. Construction of the Tulsa, Oklahoma plant started in August 2002 and culminated in the production of over 100,000 gallons of F-T diesel fuel (S-2) through 2004, specifically for this project. That fuel formed the basis of extensive demonstrations and evaluations that followed. The ultra-clean F-T fuels produced had virtually no sulfur (less than 1 ppm) and were of the highest quality in terms of ignition quality, saturation content, backend volatility, etc. Lubricity concerns were investigated to verify that commercially available lubricity additive treatment would be adequate to protect fuel injection system components. In the fuel demonstration and testing phase, two separate bus fleets were utilized. The Washington DC Metropolitan Area Transit Authority (WMATA) and Denali National Park bus fleets were used because they represented nearly opposite ends of several spectra, including: climate, topography, engine load factor, mean distance between stops, and composition of normally used conventional diesel fuel. Fuel evaluations in addition to bus fleet demonstrations included: bus fleet emission measurements; F-T fuel cold weather performance; controlled engine dynamometer

  18. Assessment of trace contaminants from a model indirect liquefaction facility. Volume V. Occupational chemical hazards of Lurgi/Fischer-Tropsch coal liquefaction

    SciTech Connect

    Walsh, P.J.; Gasper, J.R.

    1982-01-01

    This analysis investigates the potential for occupational exposure to toxic chemicals during Lurgi/Fischer-Tropsch coal liquefaction. The reference plant is a commercial-scale facility that processes 28,000 tons of coal per day. Because no such facility currently operates in the United States, much of our data is from foreign commercial-scale facilities and US pilot plants. No definitive assessment of occupational hazards can be made until US commercial-scale data is available. However, by extrapolating available data, we identify major chemical hazards of specific Lurgi/Fischer-Tropsch process streams through inhalation and dermal exposure routes. We also identify which workers are at risk and summarize procedures for mitigating potential exposures. Chemicals of interest are carbon monoxide, methane, hydrogen sulfides, tars, and oils. 11 references, 1 figure, 8 tables.

  19. Reductions in aircraft particulate emissions due to the use of Fischer-Tropsch fuels

    NASA Astrophysics Data System (ADS)

    Beyersdorf, A. J.; Timko, M. T.; Ziemba, L. D.; Bulzan, D.; Corporan, E.; Herndon, S. C.; Howard, R.; Miake-Lye, R.; Thornhill, K. L.; Winstead, E.; Wey, C.; Yu, Z.; Anderson, B. E.

    2014-01-01

    The use of alternative fuels for aviation is likely to increase due to concerns over fuel security, price stability, and the sustainability of fuel sources. Concurrent reductions in particulate emissions from these alternative fuels are expected because of changes in fuel composition including reduced sulfur and aromatic content. The NASA Alternative Aviation Fuel Experiment (AAFEX) was conducted in January-February 2009 to investigate the effects of synthetic fuels on gas-phase and particulate emissions. Standard petroleum JP-8 fuel, pure synthetic fuels produced from natural gas and coal feedstocks using the Fischer-Tropsch (FT) process, and 50% blends of both fuels were tested in the CFM-56 engines on a DC-8 aircraft. To examine plume chemistry and particle evolution with time, samples were drawn from inlet probes positioned 1, 30, and 145 m downstream of the aircraft engines. No significant alteration to engine performance was measured when burning the alternative fuels. However, leaks in the aircraft fuel system were detected when operated with the pure FT fuels as a result of the absence of aromatic compounds in the fuel. Dramatic reductions in soot emissions were measured for both the pure FT fuels (reductions in mass of 86% averaged over all powers) and blended fuels (66%) relative to the JP-8 baseline with the largest reductions at idle conditions. At 7% power, this corresponds to a reduction from 7.6 mg kg-1 for JP-8 to 1.2 mg kg-1 for the natural gas FT fuel. At full power, soot emissions were reduced from 103 to 24 mg kg-1 (JP-8 and natural gas FT, respectively). The alternative fuels also produced smaller soot (e.g., at 85% power, volume mean diameters were reduced from 78 nm for JP-8 to 51 nm for the natural gas FT fuel), which may reduce their ability to act as cloud condensation nuclei (CCN). The reductions in particulate emissions are expected for all alternative fuels with similar reductions in fuel sulfur and aromatic content regardless of the

  20. Slurry reactor design studies

    SciTech Connect

    Fox, J.M.; Degen, B.D.; Cady, G.; Deslate, F.D.; Summers, R.L. ); Akgerman, A. ); Smith, J.M. )

    1990-06-01

    The objective of these studies was to perform a realistic evaluation of the relative costs of tublar-fixed-bed and slurry reactors for methanol, mixed alcohols and Fischer-Tropsch syntheses under conditions where they would realistically be expected to operate. The slurry Fischer-Tropsch reactor was, therefore, operated at low H{sub 2}/CO ratio on gas directly from a Shell gasifier. The fixed-bed reactor was operated on 2.0 H{sub 2}/CO ratio gas after adjustment by shift and CO{sub 2} removal. Every attempt was made to give each reactor the benefit of its optimum design condition and correlations were developed to extend the models beyond the range of the experimental pilot plant data. For the methanol design, comparisons were made for a recycle plant with high methanol yield, this being the standard design condition. It is recognized that this is not necessarily the optimum application for the slurry reactor, which is being proposed for a once-through operation, coproducing methanol and power. Consideration is also given to the applicability of the slurry reactor to mixed alcohols, based on conditions provided by Lurgi for an Octamix{trademark} plant using their standard tubular-fixed reactor technology. 7 figs., 26 tabs.

  1. Comparison of PM emissions from a commercial jet engine burning conventional, biomass, and Fischer-Tropsch fuels.

    PubMed

    Lobo, Prem; Hagen, Donald E; Whitefield, Philip D

    2011-12-15

    Rising fuel costs, an increasing desire to enhance security of energy supply, and potential environmental benefits have driven research into alternative renewable fuels for commercial aviation applications. This paper reports the results of the first measurements of particulate matter (PM) emissions from a CFM56-7B commercial jet engine burning conventional and alternative biomass- and, Fischer-Tropsch (F-T)-based fuels. PM emissions reductions are observed with all fuels and blends when compared to the emissions from a reference conventional fuel, Jet A1, and are attributed to fuel properties associated with the fuels and blends studied. Although the alternative fuel candidates studied in this campaign offer the potential for large PM emissions reductions, with the exception of the 50% blend of F-T fuel, they do not meet current standards for aviation fuel and thus cannot be considered as certified replacement fuels. Over the ICAO Landing Takeoff Cycle, which is intended to simulate aircraft engine operations that affect local air quality, the overall PM number-based emissions for the 50% blend of F-T fuel were reduced by 34 ± 7%, and the mass-based emissions were reduced by 39 ± 7%.

  2. Novel approach for scaleup and scaledown of slurry bubble column reactors

    SciTech Connect

    Inga, J.R.; Morsi, B.I.

    1998-12-31

    Multiphase reactors are used in many industrial applications including Fischer-Tropsch synthesis, methanol synthesis, hydrotreatment of petroleum products, edible oil hydrogenation, coal liquefaction, etc. A new scaleup/scaledown methodology for slurry reactors based on maintaining the relative importance of mass transfer resistance in the overall reaction resistances constant through the scaleup phases was developed. This methodology allowed the authors to simulate the performance of a conceptual commercial size slurry bubble column reactor (SBCR) with a laboratory-scale stirred slurry reactor (SSR) despite the fundamental differences between the geometry and hydrodynamic as well as mass transfer behavior of these two reactor types. Simplified computer models were developed and the performance of conceptual SBCR having 7-m diameter and 30-m high operating at a gas velocity of 0.2 m/s, catalyst loading of 35 wt%, pressure of 30 bar and temperature of 523K was simulated with a laboratory-scale SSR having 4-liter size and operating at 20 Hz, 5 wt%, and same pressure and temperature of the SBCR. The simulated SBCR is capable of producing 10,000-bbl/d hydrocarbons with a catalyst productivity of 0.22 kg HC/kg cat.h and a usage ratio of 1.3. Under these conditions, the gas-liquid mass transfer resistance represents about 20% of the overall resistance of the process.

  3. NOVEL SLURRY PHASE DIESEL CATALYSTS FOR COAL-DERIVED SYNGAS

    SciTech Connect

    Dr. Dragomir B. Bukur; Dr. Ketil Hanssen; Alec Klinghoffer; Dr. Lech Nowicki; Patricia O'Dowd; Dr. Hien Pham; Jian Xu

    2001-01-07

    This report describes research conducted to support the DOE program in novel slurry phase catalysts for converting coal-derived synthesis gas to diesel fuels. The primary objective of this research program is to develop attrition resistant catalysts that exhibit high activities for conversion of coal-derived syngas.

  4. Method of inducing surface ensembles on a metal catalyst

    DOEpatents

    Miller, S.S.

    1987-10-02

    A method of inducing surface ensembles on a transition metal catalyst used in the conversion of a reactant gas or gas mixture, such as carbon monoxide and hydrogen into hydrocarbons (the Fischer-Tropsch reaction) is disclosed which comprises adding a Lewis base to the syngas (CO + H/sub 2/) mixture before reaction takes place. The formation of surface ensembles in this manner restricts the number and types of reaction pathways which will be utilized, thus greatly narrowing the product distribution and maximizing the efficiency of the Fischer-Tropsch reaction. Similarly, amines may also be produced by the conversion of reactant gas or gases, such as nitrogen, hydrogen, or hydrocarbon constituents.

  5. Method of inducing surface ensembles on a metal catalyst

    DOEpatents

    Miller, Steven S.

    1989-01-01

    A method of inducing surface ensembles on a transition metal catalyst used in the conversion of a reactant gas or gas mixture, such as carbon monoxide and hydrogen into hydrocarbons (the Fischer-Tropsch reaction) is disclosed which comprises adding a Lewis base to the syngas (CO+H.sub.2) mixture before reaction takes place. The formation of surface ensembles in this manner restricts the number and types of reaction pathways which will be utilized, thus greatly narrowing the product distribution and maximizing the efficiency of the Fischer-Tropsch reaction. Similarly, amines may also be produced by the conversion of reactant gas or gases, such as nitrogen, hydrogen, or hydrocarbon constituents.

  6. Fe-based Fischer Tropsch Synthesis of biomass-derived syngas: Effect of synthesis method

    Treesearch

    Khiet Mai; Thomas Elder; Les Groom; James J. Spivey

    2015-01-01

    Two 100Fe/4Cu/4K/6Zn catalysts were prepared using two different methods: coprecipitation or impregnation methods. The effect of the preparation methods on the catalyst structure, catalytic properties, and the conversion of biomass-derived syngas via Fischer–Tropsch synthesis was investigated. Syngas was derived from gasifying Southern pine woodchips and had the...

  7. Bubble column apparatus for separating wax from catalyst slurry

    SciTech Connect

    Neathery, James K.; Davis, Burtron H.

    2004-07-13

    Novel methods and devices for production of liquid hydrocarbon products from gaseous reactants are disclosed. In one aspect, a method for separating a liquid hydrocarbon, typically a wax, from a catalyst containing slurry is provided, comprising passing the slurry through at least one downcomer extending from an overhead separation chamber and discharging into the bottom of a slurry bubble column reactor. The downcomer includes a cross-flow filtration element for separating a substantially particle-free liquid hydrocarbon for downstream processing. In another aspect, a method for promoting plug-flow movement in a recirculating slurry bubble column reactor is provided, comprising discharging the recirculating slurry into the reactor through at least one downcomer which terminates near the bottom of the reactor. Devices for accomplishing the above methods are also provided.

  8. The development of precipitated iron catalysts with improved stability

    SciTech Connect

    Not Available

    1990-01-01

    The goal 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. This report covers testing an iron catalyst. During the last quarter, a new precipitated iron catalyst was prepared and tested in the slurry autoclave reactor at various conditions. This catalyst did not noticeably deactivate during 1250 hours of testing. This quarter, the test was extended to include performance evaluations at different conversion levels ranging from 35 to 88% at 265 and 275{degree}C. The conversion levels were varied by changing the feed rate. The catalytic performance at different conversion intervals was then integrated to approximately predict performance in a bubble column reactor. The run was shut down at the end of 1996 hours because of a 24-hour-power outage. When the power was back on, the run was restarted from room temperature. Catalytic performance during the first 300 hours after the restart-up was monitored. Overall product distributions are being tabulated as analytical laboratory data are obtained. 34 figs., 3 tabs.

  9. Abiogenic Fischer-Tropsch synthesis of methane at the Baogutu reduced porphyry copper deposit, western Junggar, NW-China

    NASA Astrophysics Data System (ADS)

    Cao, MingJian; Qin, KeZhang; Li, GuangMing; Evans, Noreen J.; Jin, LuYing

    2014-09-01

    Methane is widely developed in hydrothermal fluids from reduced porphyry copper deposits, but its origin remains enigmatic. The occurrence of methane in fluid inclusions at the Late Carboniferous Baogutu reduced porphyry copper deposit in western Junggar, Xinjiang, NW-China, presents an excellent opportunity to address this problem. A systematic study including fluid inclusion Laser-Raman and CO2-CH4 carbon isotope analyses, igneous and hydrothermal mineral H-O isotope analyses, and in situ major, trace element and Sr isotopic analyses of hydrothermal epidote was conducted to constrain the origin of CH4 and CH4-rich fluids. The δ2H and δ18O of water in equilibrium with igneous biotite ranges from -65.0‰ to -66.0‰ and +7.2‰ to +7.4‰, respectively, indicating notable degassing of probably supercritical fluids in the magma chamber. The wide range of δ2H (-58.0‰ to -107.0‰, n = 23) for water within quartz suggests the existence of significant hydrothermal fluid boiling. Water-rock interaction is the most likely mechanism leading to the wide range of δ18O values for water in vein quartz with water/rock ratios (wt.% in O) of 0.15 to 0.75 and 0.13 to 0.46 for a closed and open system, respectively. Detailed Laser-Raman analyses indicate CO2 in apatite included in granodiorite porphyry phenocrystic biotite that records the carbon species of the early stage magmatic stage, whereas later hydrothermal fluids containing CH4 with trace or without CO2 are found in inclusions of vein quartz. We propose that CH4 is probably transformed from CO2 by Fischer-Tropsch type reactions at 500 °C, assumed from CO2-CH4 C isotope equilibrium. The (87Sr/86Sr)i of hydrothermal epidote yields values of 0.70369-0.70404, consistent with that reported for the whole rocks. The δ13CCH4 (-28.6‰ to -22.6‰) and δ2HCH4 (-108.0‰ to -59.5‰) are characteristic of abiogenic methane. The measured δ13CCO2 shows a slightly depleted 13C (-13.5‰ to -7.2‰) relative to upper mantle

  10. Fischer-Tropsch Synthesis. Reduction Behavior and Catalytic Activity of Fe-Ce Systems

    SciTech Connect

    Perez-Alonso, F.J.; Ojeda, M.; Herranz, T.; Fierro, J.L.G.

    2005-04-26

    Several Fe-Ce catalysts for FT synthesis were prepared following two different methods: coprecipitation from Fe and Ce nitrate solutions and a physical mixture of pure Fe and Ce precursors. The iron phases present in the activated catalysts were identified by XRD and Moessbauer spectroscopy. A good correlation between both techniques was found. The results revealed that the cerium oxide in the samples prepared by coprecipitation produces two effects: (i), stabilization of metastable species (Fe1-xO), and (ii), a decrease in the crystallite size of the iron species upon increasing Ce-contents, as inferred from an increase in superparamagnetic species. The catalysts were tested in CO hydrogenation in a flow reactor. It was found that selectivity towards light olefins increases for the coprecipitated Ce-containing catalysts, whereas CO conversion followed the opposite trend. Since the Fe1-xO phase was detected in these catalysts, it is suggested that the formation of the Fe1-xO phase would be responsible for the drop in catalytic activity.

  11. Enhanced catalyst for conversion of syngas to liquid motor fuels

    DOEpatents

    Coughlin, P.K.; Rabo, J.A.

    1985-12-03

    Synthesis gas comprising carbon monoxide and hydrogen is converted to C[sub 5][sup +] hydrocarbons suitable for use as liquid motor fuels by contact with a dual catalyst system capable of enhancing the selectivity of said conversion to motor fuel range hydrocarbons and the quality of the resulting motor fuel product. The catalyst composition employs a Fischer-Tropsch catalyst, together with a co-catalyst/support component comprising a SAPO silicoaluminophosphate, non-zeolitic molecular sieve catalyst.

  12. Enhanced catalyst for conversion of syngas to liquid motor fuels

    DOEpatents

    Coughlin, Peter K.; Rabo, Jule A.

    1985-01-01

    Synthesis gas comprising carbon monoxide and hydrogen is converted to C.sub.5.sup.+ hydrocarbons suitable for use as liquid motor fuels by contact with a dual catalyst system capable of enhancing the selectivity of said conversion to motor fuel range hydrocarbons and the quality of the resulting motor fuel product. The catalyst composition employs a Fischer-Tropsch catalyst, together with a co-catalyst/support component comprising SAPO silicoaluminophosphate, non-zeolitic molecular sieve catalyst.

  13. Enhanced anaerobic degradation of Fischer-Tropsch wastewater by integrated UASB system with Fe-C micro-electrolysis assisted.

    PubMed

    Wang, Dexin; Ma, Wencheng; Han, Hongjun; Li, Kun; Xu, Hao; Fang, Fang; Hou, Baolin; Jia, Shengyong

    2016-12-01

    Coupling of the Fe-C micro-electrolysis (IC-ME) into the up-flow anaerobic sludge blanket (UASB) was developed for enhanced Fischer-Tropsch wastewater treatment. The COD removal efficiency and methane production in R3 with IC-ME assisted both reached up to 80.6 ± 1.7% and 1.38 ± 0.11 L/L·d that higher than those values in R1 with GAC addition (63.0 ± 3.4% and 0.95 ± 0.09 L/L·d) and R2 with ZVI addition (74.5 ± 2.8% and 1.21 ± 0.09 L/L·d) under the optimum HRT (5 d). The Fe corrosion as electron donor reduced the ORP values and stimulated the activities of hydrogenotrophic methanogens to lower H2 partial pressure in R2 and R3. Additionally, Fe(2+) as by-product of iron corrosion, its presence could effectively increase the percentage of protein content in tightly bound extracellular polymeric substances (TB-EPS) to promote better bioflocculation, increasing to 90.5 mg protein/g·VSS (R2) and 106.3 mg protein/g·VSS (R3) while this value in R1 was simply 56.6 mg protein/g·VSS. More importantly, compared with R1, the excess accumulation of propionic acid and butyric acid in system was avoided. The macroscopic galvanic cells around Fe-C micro-electrolysis carriers in R3, that larger than microscopic galvanic cells in R2, further accelerate to transfer the electrons from anodic Fe to cathodic carbon that enhance interspecies hydrogen transfer, making the decomposition of propionic acid and butyric acid more thermodynamically feasible, finally facilitate more methane production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Laboratory Studies of Fischer-Tropsch-Type Reactions and Their Implications for Organics in Asteroids and Comets

    NASA Technical Reports Server (NTRS)

    Nuth, Joseph

    2011-01-01

    We have been studying Fischer-Tropsch type (FTT) reactions as a source for organic materials both in the gas phase of the solar nebula and incorporated into primitive comets and asteroids for almost 10 years, and over this time our concept has evolved greatly from the standard "catalytic" model to a much more robust chemical scenario. Our simulations have been conducted at temperatures that are much higher than we like, primarily for practical reasons such as the timescale of individual reactions, and we are just starting a series of measurements to allow us to measure reaction rates at temperatures from 873K down to as low as 373K. We have preliminary data on the carbon (d13C = -50) & nitrogen (d15N = +9.5) isotopic fractionation at 873K, but not on materials produced at lower temperature. Isotope values are on the VPDB scale for carbon and vs. Air for nitrogen. We have also investigated the noble gas trapping efficiency of the FTT process by adding a small amount of a noble gas mix to our standard synthesis mix. The noble gas ratio is 49:49:1:1::Ne:Ar:Kr:Xe. Xe and Kr are trapped at 873K and are more efficiently trapped at 673K with no isotopic fractionation at either temperature. Ar trapping is detected at 673K, but not at 873K. Ne has not yet been observed in our samples. The solar nebula was an extremely complex system, mixing materials from the innermost regions out to well into the zones where comets formed and thus mixing highly processed nebular materials with grains and coatings formed before the nebula began to collapse. Laboratory studies may provide the means to separate such diverse components based on carbon or nitrogen isotopic fractionation or the quantities of noble gases trapped in grain coatings and their thermal release patterns, among other observables. The ultimate goal of laboratory synthesis of nebular analogs is to provide the means to identifY the conditions under which natural samples were formed and the signatures of subsequent

  15. Technology development for cobalt F-T catalysts. Quarterly technical progress report No. 5, October 1, 1993--December 31, 1993

    SciTech Connect

    Singleton, A.H.

    1994-05-31

    The goal of this project is the development of a commercially viable, cobalt-based Fischer-Tropsch (F-T) catalyst for use in a slurry bubble column reactor. Cobalt-based catalysts have long been known as being active for F-T synthesis. They typically possess greater activity than iron-based catalysts, historically the predominant catalyst being used commercially for the conversion of syngas based on coal, but possess two disadvantages that somewhat lessen its value: (1) cobalt tends to make more methane than iron does, and (2) cobalt is less versatile with low H{sub 2}/CO ratio syngas due to its lack of water-gas shift activity. Therefore, the major objectives of this work are (1) to develop a cobalt-based F-T catalyst with low (< 5 %) methane selectivity, (2) to develop a cobalt-based F-T catalyst with water-gas shift activity, and (3) to combine both these improvements into one catalyst. It will be demonstrated that these catalysts have the desired activity, selectivity, and life, and can be made reproducibly. Following this experimental work, a design and a cost estimate will be prepared for a plant to produce sufficient quantities of catalyst for scale-up studies.

  16. Technology development for cobalt F-T catalysts. Quarterly technical progress report number 10, January 1--March 31, 1995

    SciTech Connect

    Singleton, A.H.

    1995-06-28

    The goal of this project is the development of a commercially-viable, cobalt-based Fischer-Tropsch (F-T) catalyst for use in a slurry bubble column reactor. The major objectives of this work are (1) to develop a cobalt-based F-T catalyst with low (< 5%) methane selectivity, (2) to develop a cobalt-based F-T catalyst with water-gas shift activity, and (3) to combine both these improvements into one catalyst. The project consists of five major tasks: catalyst development; catalyst testing; catalyst reproducibility tests; catalyst aging tests; and preliminary design and cost estimate for a demonstrate scale catalyst production facility. Technical accomplishments during this reporting period include the following. It appears that the higher activity obtained for the catalysts prepared using an organic solution and reduced directly without prior calcination was the result of higher dispersions obtained under such pretreatment. A Ru-promoted Co catalyst on alumina with 30% Co loading exhibited a 4-fold increase in dispersion and a 2-fold increase in activity in the fixed-bed reactor from that obtained with the non-promoted catalyst. Several reactor runs have again focused on pushing conversion to higher levels. The maximum conversion obtained has been 49.7% with 26g catalyst. Further investigations of the effect of reaction temperature on the performance of Co catalysts during F-T synthesis were started using a low activity catalyst and one of the most active catalysts. The three 1 kg catalyst batches prepared by Calsicat for the reproducibility and aging studies were tested in both the fixed-bed and slurry bubble column reactors under the standard reaction conditions. The effects of adding various promoters to some cobalt catalysts have also been addressed. Results are presented and discussed.

  17. Microemulsion impregnated catalyst composite and use thereof in a synthesis gas conversion process

    DOEpatents

    Abrevaya, Hayim; Targos, William M.

    1987-01-01

    A catalyst composition for synthesis gas conversion comprising a ruthenium metal component deposited on a support carrier wherein the average metal particle size is less than about 100 A. The method of manufacture of the composition via a reverse micelle impregnation technique and the use of the composition in a Fischer-Tropsch conversion process is also disclosed.

  18. Microemulsion impregnated catalyst composite and use thereof in a synthesis gas conversion process

    DOEpatents

    Abrevaya, H.; Targos, W.M.

    1987-12-22

    A catalyst composition is described for synthesis gas conversion comprising a ruthenium metal component deposited on a support carrier wherein the average metal particle size is less than about 100 A. The method of manufacture of the composition via a reverse micelle impregnation technique and the use of the composition in a Fischer-Tropsch conversion process is also disclosed.

  19. Catalyst for converting synthesis gas to liquid motor fuels

    DOEpatents

    Coughlin, Peter K.

    1986-01-01

    The addition of an inert metal component, such as gold, silver or copper, to a Fischer-Tropsch catalyst comprising cobalt enables said catalyst to convert synthesis gas to liquid motor fuels at about 240.degree.-370.degree. C. with advantageously reduced selectivity of said cobalt for methane in said conversion. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.

  20. Technology development for cobalt F-T catalysts. Quarterly technical progress report No. 8, July 1, 1994--September 30, 1994

    SciTech Connect

    Singleton, A.H.

    1995-04-18

    The objective of this project is to investigate the influence of various promoters, additives, and supports on minimizing the methane selectivity and increasing the water-gas shift (WGS) activity of cobalt (Co) Fischer-Tropsch (F-T) catalysts. The ultimate goal of this investigation is to identify and demonstrate a catalyst preparation procedure that will be scaled up for the reproducible synthesis of commercial quantities of supported Co catalysts with desired activity, selectivity, and lifetime for use in F-T synthesis in three-phase slurry bubble column reactors. Accomplishments for this quarter are: Four new catalysts were formulated and prepared during this period under both subtasks 1.2 and 1.3 and five more catalysts were prepared by Calsicat; The characterization of all the catalysts in order to determine their physical properties (BET surface area, pore volume, pore size diameter, particle size distribution), as well as the cobalt reducibility, extent of reduction, and dispersion) was continued; Seven new catalysts have been tested for their F-T synthesis performance; An investigation of the effect of pre-treatment (i.e. calcination in static air versus flowing air, direct reduction without prior calcination) of a selected number of catalysts upon their performance for F-T synthesis was continued during this period.

  1. Enhanced catalyst for converting synthesis gas to liquid motor fuels

    DOEpatents

    Coughlin, Peter K.

    1986-01-01

    The conversion of synthesis gas to liquid molar fuels by means of a cobalt Fischer-Tropsch catalyst composition is enhanced by the addition of molybdenum, tungsten or a combination thereof as an additional component of said composition. The presence of the additive component increases the olefinic content of the hydrocarbon products produced. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.

  2. Hierarchical structured α-Al2O3 supported S-promoted Fe catalysts for direct conversion of syngas to lower olefins.

    PubMed

    Zhou, Xiangping; Ji, Jian; Wang, Di; Duan, Xuezhi; Qian, Gang; Chen, De; Zhou, Xinggui

    2015-05-25

    Hierarchical structured α-Al2O3 is shown to be able to effectively disperse and immobilize iron species, in comparison with commercial α-Al2O3. After promotion using an appropriate amount of sulfur, iron catalysts exhibit not only enhanced Fischer-Tropsch synthesis activity and selectivity toward lower olefins, but also increased resistance against carbon deposits.

  3. Catalyst and process for converting synthesis gas to liquid motor fuels

    DOEpatents

    Coughlin, Peter K.

    1987-01-01

    The addition of an inert metal component, such as gold, silver or copper, to a Fischer-Tropsch catalyst comprising cobalt enables said catalyst to convert synthesis gas to liquid motor fuels at about 240.degree.-370.degree. C. with advantageously reduced selectivity of said cobalt for methane in said conversion. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.

  4. An Investigation into the Effects of Mn Promotion on the Activity and Selectivity of Co/SiO2 for Fischer - Tropsch Synthesis: Evidence for Enhanced CO Adsorption and Dissociation

    SciTech Connect

    Johnson, Gregory R.; Werner, Sebastian; Bell, Alexis T.

    2016-03-04

    Mn is an effective promoter for improving the activity and selectivity of Co-based Fischer-Tropsch synthesis (FTS) catalysts, but the mechanism by which this promoter functions is poorly understood. The work reported here was aimed at defining the manner in which Mn interacts with Co and determining how these interactions affect the activity and selectivity of Co. Detailed measurements are reported for the kinetics of FTS as a function of Mn/Co ratio, temperature, and reactant partial pressure. These data are described by a single, two-parameter rate expression. Mn promotion was found to increase both the apparent rate constant for CO consumption and the CO adsorption constant. Further evidence for enhanced CO adsorption and dissociation was obtained from measurements of temperature-programmed desorption of CO and CO disproportionation rates, respectively. Our quantitative analysis of elemental maps obtained by STEM-EDS revealed that the promoter accumulates preferentially on the surface of Co nanoparticles at low Mn loadings, resulting in a rapid onset of improvements in the product selectivity as the Mn loading increases. For catalysts prepared with loadings higher than Mn/Co = 0.1, the additional Mn accumulates in the form of nanometer-scale particles of MnO on the support. In situ IR spectra of adsorbed CO show that Mn promotion increases the abundance of adsorbed CO with weakened C-O bonds. Furthermore, it is proposed that the cleavage of the C-O bond is promoted through Lewis acid-base interactions between the Mn2+ cations located at the edges of MnO islands covering the Co nanoparticles and the O atom of CO adsorbates adjacent to the MnO islands. The observed decrease in selectivity to CH4 and the increased selectivity to C5+ products with increasing Mn/Co ratio are attributed to a decrease in the ratio of adsorbed H to CO on the surface of the supported Co nanoparticles.

  5. Technology development for cobalt F-T catalysts. Quarterly technical progress report No. 9, October 1, 1994--December 31, 1994

    SciTech Connect

    Singleton, A.H.

    1995-05-11

    The objective of this Project is to investigate the influence of various promoters, additives, and supports on minimizing the methane selectivity and increasing the water-gas shift (WGS) activity of cobalt (Co) Fischer-Tropsch (F-T) catalysts. The ultimate goal of this investigation is to identify and demonstrate a catalyst preparation Procedure that will be scaled up for the reproducible synthesis of commercial quantities of supported CO catalysts with desired activity, sleectivity, and lifetime for use in F-T synthesis in three-phase slurry bubble column reactors. Seven new catalysts were formulated and prepared during this period under both subtasks 1.2 and 1.3. Two more catalysts were prepared by Calsicat. The characterization of all the catalysts in order to determine their physical properties (BET surface area, pore volume, pore size diameter, particle size distribution), as well as the cobalt reducibility, extent of reduction, and dispersion) was continued. Fixed-bed reactor testing of the catalysts was continued. Six new catalysts were tested for their F-T synthesis performance. An investigation of the effect of pretreatment in various atmospheres (calcination in air or nitrogen prior to reduction in hydrogen, direct reduction without prior calcination, and reductiono)ddation-reduction (ROR)) of a selected number of catalysts upon their performance for F-T synthesis was continued during this period. Under subtask 2.2 during this reporting period a total of 11 runs were made in the two slurry bubble column reactors with eleven catalysts, including five on alumina, two from Calsicat, one WGS blend, and three on silica support. Four high CO conversion runs were made. Data were compiled to compare the CO conversions and product selectivities of the-methane reduction catalysts.

  6. Relating rheological measurements to primary and secondary skin feeling when mineral-based and Fischer-Tropsch wax-based cosmetic emulsions and jellies are applied to the skin.

    PubMed

    Bekker, M; Webber, G V; Louw, N R

    2013-08-01

    Rheology measurements were correlated to skin sensations occurring when cream and petroleum jelly cosmetic products containing different amounts of synthetic Fischer-Tropsch wax were applied to the skin. A panel of 15 people with a background in cosmetic product development were asked to rate skin feelings when a range of petroleum jelly and cream samples are applied to the skin. Primary skin feel, or the spreadability of a cosmetic product, was correlated to the product's flow onset and maximum viscosity as measured by a Anton Paar rheometer, whereas secondary skin feel or the sensation occurring at the end of application when the product was completely rubbed into the skin was correlated to the product's viscosity measured at high shear rates. The cream samples prepared with a petroleum jelly containing 10% and 20% Fischer-Tropsch wax fell within the boundary of good primary skin feeling of cream products. Predominantly, synthetic petroleum jellies were given the best assessments in terms of primary skin feeling and were used with mineral-based petroleum jellies to determine the boundary of good primary skin feeling for petroleum jelly products. The further away a product falls from this rheological boundary the poorer the skin feeling assessment appears to be by the panel. Products containing Fischer-Tropsch waxes were given the best assessment by the panel for secondary skin feeling. Comments from the panel include that these products feel silky and light on the skin. The higher the Fischer-Tropsch wax content, the lower viscosity was at high shear rate (ϒ = 500 s(-1) ) and the higher the assessment by the panel. Rheological measurements can be used to objectively determine skin sensation when products are applied to the skin; this may shorten research and development times. A rheology boundary of certain product viscosity and shear stress applied is associated with good primary skin feeling for lotions, creams and petroleum jellies. Lower product viscosity

  7. Enhanced catalyst and process for converting synthesis gas to liquid motor fuels

    DOEpatents

    Coughlin, Peter K.

    1986-01-01

    The conversion of synthesis gas to liquid molar fuels by means of a cobalt Fischer-Tropsch catalyst composition is enhanced by the addition of molybdenum, tungsten or a combination thereof as an additional component of said composition. The presence of the additive component increases the olefinic content of the hydrocarbon products produced. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.

  8. Comparing a Fischer-Tropsch Alternate Fuel to JP-8 and Their 50-50 Blend: Flow and Flame Visualization Results

    NASA Technical Reports Server (NTRS)

    Hicks, Yolanda R.; Tacina, M.

    2013-01-01

    Combustion performance of a Fischer-Tropsch (FT) jet fuel manufactured by Sasol was compared to JP-8 and a 50-50 blend of the two fuels, using the NASA/Woodward 9 point Lean Direct Injector (LDI) in its baseline configuration. The baseline LDI configuration uses 60deg axial air-swirlers, whose vanes generate clockwise swirl, in the streamwise sense. For all cases, the fuel-air equivalence ratio was 0.455, and the combustor inlet pressure and pressure drop were 10-bar and 4 percent. The three inlet temperatures used were 828, 728, and 617 K. The objectives of this experiment were to visually compare JP-8 flames with FT flames for gross features. Specifically, we sought to ascertain in a simple way visible luminosity, sooting, and primary flame length of the FT compared to a standard JP grade fuel. We used color video imaging and high-speed imaging to achieve these goals. The flame color provided a way to qualitatively compare soot formation. The length of the luminous signal measured using the high speed camera allowed an assessment of primary flame length. It was determined that the shortest flames resulted from the FT fuel.

  9. Toward a more comprehensive greenhouse gas emissions assessment of biofuels: the case of forest-based fischer-tropsch diesel production in Finland.

    PubMed

    Soimakallio, Sampo

    2014-01-01

    Increasing the use of biofuels influences atmospheric greenhouse gas concentrations. Although widely recognized, uncertainties related to the particular impacts are typically ignored or only partly considered. In this paper, various sources of uncertainty related to the GHG emission savings of biofuels are considered comprehensively and transparently through scenario analysis and stochastic simulation. Technology and feedstock production chain-specific factors, market-mediated factors and climate policy time frame issues are reflected using as a case study Fischer-Tropsch diesel derived from boreal forest biomass in Finland. This case study shows that the GHG emission savings may be positive or negative in many of the cases studied, and are subject to significant uncertainties, which are mainly determined by market-mediated factors related to fossil diesel substitution. Regardless of the considerable uncertainties, some robust conclusions could be drawn; it was likely of achieving some sort of but unlikely of achieving significant savings in the GHG emissions within the 100 year time frame in many cases. Logging residues (branches) performed better than stumps and living stem wood in terms of the GHG emission savings, which could be increased mainly by blocking carbon leakage. Forest carbon stock changes also significantly contributed to the GHG emission savings.

  10. Synthesis, characterization, and Fischer-Tropsch performance of cobalt/zinc aluminate nanocomposites via a facile and corrosion-free coprecipitation route

    NASA Astrophysics Data System (ADS)

    Liu, Zhenxin; Xing, Yu; Xue, Yingying; Wu, Depeng; Fang, Shaoming

    2015-02-01

    Literature about ZnAl2O4-supported cobalt Fischer-Tropsch synthesis (FTS) catalytic materials is sparse. A series of cobalt-containing nanocomposites, supported by nanosized ZnAl2O4 spinel (i.e., a complex oxide of about 6.4 nm) or alumina (i.e., a simple oxide of about 6.2 nm), were prepared via urea-gelation, coprecipitation, or impregnation methods followed by stepwise reduction. These materials were examined by XRD, TGA, nitrogen sorption, FESEM, and EDS. Effects of corrosion and pore size distributions on materials preparation were also investigated. The "coprecipitation/stepwise reduction" route is facile and suitable to prepare nanosized ZnAl2O4-supported Co0 nanocomposites. At similar CO conversions, the coprecipitated Co/ZnAl2O4 exhibits significantly lower C1 hydrocarbon distribution, slightly lower C5+ hydrocarbon distribution, significantly higher C2-C4 hydrocarbon distribution, and significantly higher olefin/paraffin ratio of C2-C4 than Co/γ-Al2O3.

  11. Assessment of fuel-cycle energy use and greenhouse gas emissions for Fischer-Tropsch diesel from coal and cellulosic biomass.

    SciTech Connect

    Xie, X.; Wang, M.; Han, J.

    2011-04-01

    This study expands and uses the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model to assess the effects of carbon capture and storage (CCS) technology and cellulosic biomass and coal cofeeding in Fischer-Tropsch (FT) plants on energy use and greenhouse gas (GHG) emissions of FT diesel (FTD). To demonstrate the influence of the coproduct credit methods on FTD life-cycle analysis (LCA) results, two allocation methods based on the energy value and the market revenue of different products and a hybrid method are employed. With the energy-based allocation method, fossil energy use of FTD is less than that of petroleum diesel, and GHG emissions of FTD could be close to zero or even less than zero with CCS when forest residue accounts for 55% or more of the total dry mass input to FTD plants. Without CCS, GHG emissions are reduced to a level equivalent to that from petroleum diesel plants when forest residue accounts for 61% of the total dry mass input. Moreover, we show that coproduct method selection is crucial for LCA results of FTD when a large amount of coproducts is produced.

  12. Enhanced treatment of Fischer-Tropsch (F-T) wastewater using the up-flow anaerobic sludge blanket coupled with bioelectrochemical system: Effect of electric field.

    PubMed

    Wang, Dexin; Han, Hongjun; Han, Yuxing; Li, Kun; Zhu, Hao

    2017-05-01

    The coupling of bioelectrochemical system (BES) with an up-flow anaerobic sludge blanket (UASB) was established for enhanced Fischer-Tropsch (F-T) wastewater treatment while the UASB (control group) was operated in parallel. The presence of electric field could offer system a more reductive micro-environment that lower the ORP values and maintain the appropriate pH range, resulting in the higher chemical oxygen demand (COD) removal efficiency and methane production for BES-UASB (86.8% and 2.31±0.1L/(L·d)) while those values in control group were 72.1% and 1.77±0.08L/(L·d). In addition, the coupled system could promote sludge granulation to perform a positive effect on maintaining stability of pollutants removal. The high-throughput 16S rRNA gene pyrosequencing in this study further confirmed that the promoting direct interspecies electron transfer (DIET) between Geobacter and Methanosarcina might be established in BES-UASB to improve the syntrophic degradation of propionate and butyrate, finally facilitated completely methane production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Catalyst for selective conversion of synthesis gas and method of making the catalyst

    DOEpatents

    Dyer, Paul N.; Pierantozzi, Ronald

    1986-01-01

    A Fischer-Tropsch (F-T) catalyst, a method of making the catalyst and an F-T process utilizing the catalyst by which synthesis gas, particularly carbon-monoxide rich synthesis gas is selectively converted to higher hydrocarbons of relatively narrow carbon number range. In general, the selective and notably stable catalyst, consists of an inert carrier first treated with a Group IV B metal compound (such as zirconium or titanium), preferably an alkoxide compound, and subsequently treated with an organic compound of an F-T metal catalyst, such as cobalt, iron or ruthenium carbonyl. Reactions with air and water and calcination are specifically avoided in the catalyst preparation procedure.

  14. 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.

  15. 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.

  16. Quantification of trace O-containing compounds in GTL process samples via Fischer-Tropsch reaction by comprehensive two-dimensional gas chromatography/mass spectrometry.

    PubMed

    Fernandes, Daniella R; Pereira, Vinícius B; Stelzer, Karen T; Gomes, Alexandre O; Neto, Francisco R Aquino; Azevedo, Débora A

    2015-11-01

    Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS) was successfully applied to eight real Brazilian Fischer-Tropsch (FT) product samples for the quantitative analysis of O-containing compounds. It not only allowed identifying and quantifying simultaneously a large number of O-containing compounds but also resolved many co-eluting components, such as carboxylic acids, which co-elute in one-dimensional gas chromatography. The homologous series of alcohols and carboxylic acids as trimethylsilyl derivatives were detected and identified at trace levels. The absolute quantification of each compound was accomplished with reliability using analytical curves. Linear alcohols (from C5 to C19), branched alcohols (C6-C13) and carboxylic acids (C4 to C12) were obtained in the range of 1.58 mg g(-1) to 14.75 mg g(-1), 0.51 mg g(-1) to 1.12 mg g(-1) and 0.21 mg g(-1) to 1.63 mg g(-1) of FT product samples, respectively. GC×GC-TOFMS provided a linear range (from 0.3 ng µL(-1) to 10 ng µL(-1)), good precision (<8%), and excellent accuracy (recovery range of 77% to 118%) for quantification of individual O-containing compounds in FT product samples. The results can benefit the development of gas-to-liquid technologies from natural gas and guide the choice of an FT conversion process that generates clean products with higher added value.

  17. Mixed Alcohol Synthesis Catalyst Screening

    SciTech Connect

    Gerber, Mark A.; White, James F.; Stevens, Don J.

    2007-09-03

    National Renewable Energy Laboratory (NREL) and Pacific Northwest National Laboratory (PNNL) are conducting research to investigate the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). PNNL is tasked with obtaining commercially available or preparing promising mixed-alcohol catalysts and screening them in a laboratory-scale reactor system. Commercially available catalysts and the most promising experimental catalysts are provided to NREL for testing using a slipstream from a pilot-scale biomass gasifier. From the standpoint of producing C2+ alcohols as the major product, it appears that the rhodium catalyst is the best choice in terms of both selectivity and space-time yield (STY). However, unless the rhodium catalyst can be improved to provide minimally acceptable STYs for commercial operation, mixed alcohol synthesis will involve significant production of other liquid coproducts. The modified Fischer-Tropsch catalyst shows the most promise for providing both an acceptable selectivity to C2+ alcohols and total liquid STY. However, further optimization of the Fischer-Tropsch catalysts to improve selectivity to higher alcohols is highly desired. Selection of a preferred catalyst will likely entail a decision on the preferred coproduct slate. No other catalysts tested appear amenable to the significant improvements needed for acceptable STYs.

  18. Catalysts for conversion of syngas to liquid motor fuels

    DOEpatents

    Rabo, Jule A.; Coughlin, Peter K.

    1987-01-01

    Synthesis gas comprising carbon monoxide and hydrogen is converted to C.sub.5.sup.+ hydrocarbons suitable for use as liquid motor fuels by contact with a dual catalyst composition capable of ensuring the production of only relatively minor amounts of heavy products boiling beyond the diesel oil range. The catalyst composition, having desirable stability during continuous production operation, employs a Fischer-Tropsch catalyst, together with a co-catalyst/support component. The latter component is a steam-stabilized zeolite Y catalyst of hydrophobic character, desirably in acid-extracted form.

  19. Fischer-Tropsch synthesis of hydrocarbons during sub-solidus alteration of the Strange Lake peralkaline granite, Quebec/Labrador, Canada

    SciTech Connect

    Salvi, S.; Williams-Jones, A.E.

    1997-01-01

    The composition of the carbonic phase(s) of fluid inclusions in pegmatite quartz from the Strange Lake peralkaline complex has been analysed by gas chromatography using online extraction of inclusion contents and a PoraPLOT{reg_sign} Q capillary column. The measured gas species are, in order of abundance, CH{sub 4} H{sub 2}, C{sub 2}H{sub 6}, CO{sub 2}, N{sub 2}, C{sub 3}H{sub 8}, n-C{sub 4}H{sub 10}, n-C{sub 5}H{sub 12}, C{sub 2}H{sub 2}-i-C{sub 4}H{sub 10}, and C{sub 2}H{sub 4}. Minor amounts of i-C{sub 5}H{sub 12}, n-C{sub 6}H{sub 14}, i-C{sub 6}H{sub 14}, and neo-C{sub 6}H{sub 14}, were also detected (but not quantified) in some samples. A suite of quartz samples from Ca-metasomatised pegmatites contains fluid inclusions with a similar distribution of hydrocarbons but much higher proportions of CO{sub 2}. The carbonic fluid coexisted immiscibly with a brine, which on the basis of field and petrographic evidence, was interpreted to have originated from the magma. However, thermodynamic calculations indicate that the above gas species, specifically the hydrocarbons, could not have coexisted at equilibrium in the proportions measured, at any geologically reasonable conditions either prior to or post entrapment. We propose, instead, that the gas compositions measured in the Strange Lake inclusions, and in inclusions from other alkalic complexes, resulted from the production of H{sub 2} during the alteration of arfvedsonite to aegirine, and the subsequent reaction of this H{sub 2} with orthomagmatic CO{sub 2} and CO to form hydrocarbons in a magnetite-catalysed Fischer-Tropsch synthesis. Locally, influx of an oxidised calcic brine, derived externally from the pluton, altered the original composition of the fluid by converting hydrocarbons to CO{sub 2}. 70 refs., 7 figs., 5 tabs.

  20. Slurry

    NASA Astrophysics Data System (ADS)

    Jiang, Ting; Lei, Hong

    2014-11-01

    With magnetic heads operating closer to hard disks, the hard disks must be ultra-smooth. The abrasive-free polishing (AFP) performance of cumene hydroperoxide (CHP) as the initiator in H2O2-based slurry for hard disk substrate was investigated in our work, and the results showed that the slurry including CHP could improve the material removal rate (MRR) and also reduce surface roughness. Electron spin-resonance spectroscopy (EPR), electrochemical measurement and Auger electron spectroscopy (AES) were conducted to investigate the acting mechanism with CHP during the polishing process. Compared with the H2O2 slurry, the EPR analysis shows that the CHP-H2O2 slurry provides a higher concentration of the HOO free radical. In addition, the AES analysis shows the oxidization reaction occurs in the external layer of the substrate surface. Furthermore, electrochemical measurements reveal that CHP can promote the electrochemical effect in AFP and lead to the increase of MRR.

  1. Decomposition studies of filtered slurries using the enhanced comprehensive catalyst

    SciTech Connect

    Wilmarth, W.R.; Crawford, C.L.; Peterson, R.A.

    1997-11-13

    This study examined decomposition of the soluble phenylborates at elevated temperatures (45 degrees Celsius) to determine the effects of filtering the solid tetraphenylborate, solid sludge and monosodium titanate and spiking additional levels of transition metal catalyst.

  2. Slurry phase synthesis of oxygenates with nanometer particle catalysts

    SciTech Connect

    Mahajan, D.; Wegrzyn, J.; Goland, A.

    1995-07-01

    The purpose of this initiative is to ultimately develop an economically viable route to isobutanol by catalytic conversion of synthesis gas derived from coal or natural gas. This report presents our studies on the review of other work and experiments performed to date utilizing an iron oxide catalyst.

  3. Technology development for iron Fischer-Tropsch catalysts, September 30, 1991. Technical progress report for quarterly period ending September 30, 1991

    SciTech Connect

    Davis, B.H.

    1991-12-31

    Although the oxidation process of Fe(OH){sub 2} and the mechanism of formation of {gamma}-FeOOH have been studied by several groups, many questions still need to be answered. In addition, the procedure for the synthesis of pure {gamma}-FeOOH has not been well defined. This study is to an attempt to define better the chemistry associated with oxidizing Fe{sup 2+} to {gamma}-FeOOH, and to provide a rationale for scaling this method up to produce kg/hr amounts of {gamma}-FeOOH.

  4. ADVANCED COMPUTATIONAL MODEL FOR THREE-PHASE SLURRY REACTORS

    SciTech Connect

    Goodarz Ahmadi

    2000-11-01

    In the first year of the project, solid-fluid mixture flows in ducts and passages at different angle of orientations were analyzed. The model predictions are compared with the experimental data and good agreement was found. Progress was also made in analyzing the gravity chute flows of solid-liquid mixtures. An Eulerian-Lagrangian formulation for analyzing three-phase slurry flows in a bubble column is being developed. The approach uses an Eulerian analysis of gas liquid flows in the bubble column, and makes use of the Lagrangian particle tracking procedure to analyze the particle motions. Progress was also made in developing a rate dependent thermodynamically consistent model for multiphase slurry flows in a state of turbulent motion. The new model includes the effect of phasic interactions and leads to anisotropic effective phasic stress tensors. Progress was also made in measuring concentration and velocity of particles of different sizes near a wall in a duct flow. The formulation of a thermodynamically consistent model for chemically active multiphase solid-fluid flows in a turbulent state of motion was also initiated. The general objective of this project is to provide the needed fundamental understanding of three-phase slurry reactors in Fischer-Tropsch (F-T) liquid fuel synthesis. The other main goal is to develop a computational capability for predicting the transport and processing of three-phase coal slurries. The specific objectives are: (1) To develop a thermodynamically consistent rate-dependent anisotropic model for multiphase slurry flows with and without chemical reaction for application to coal liquefaction. Also to establish the material parameters of the model. (2) To provide experimental data for phasic fluctuation and mean velocities, as well as the solid volume fraction in the shear flow devices. (3) To develop an accurate computational capability incorporating the new rate-dependent and anisotropic model for analyzing reacting and

  5. ADVANCED COMPUTATIONAL MODEL FOR THREE-PHASE SLURRY REACTORS

    SciTech Connect

    Goodarz Ahmadi

    2001-10-01

    In the second year of the project, the Eulerian-Lagrangian formulation for analyzing three-phase slurry flows in a bubble column is further developed. The approach uses an Eulerian analysis of liquid flows in the bubble column, and makes use of the Lagrangian trajectory analysis for the bubbles and particle motions. An experimental set for studying a two-dimensional bubble column is also developed. The operation of the bubble column is being tested and diagnostic methodology for quantitative measurements is being developed. An Eulerian computational model for the flow condition in the two-dimensional bubble column is also being developed. The liquid and bubble motions are being analyzed and the results are being compared with the experimental setup. Solid-fluid mixture flows in ducts and passages at different angle of orientations were analyzed. The model predictions were compared with the experimental data and good agreement was found. Gravity chute flows of solid-liquid mixtures is also being studied. Further progress was also made in developing a thermodynamically consistent model for multiphase slurry flows with and without chemical reaction in a state of turbulent motion. The balance laws are obtained and the constitutive laws are being developed. Progress was also made in measuring concentration and velocity of particles of different sizes near a wall in a duct flow. The technique of Phase-Doppler anemometry was used in these studies. The general objective of this project is to provide the needed fundamental understanding of three-phase slurry reactors in Fischer-Tropsch (F-T) liquid fuel synthesis. The other main goal is to develop a computational capability for predicting the transport and processing of three-phase coal slurries. The specific objectives are: (1) To develop a thermodynamically consistent rate-dependent anisotropic model for multiphase slurry flows with and without chemical reaction for application to coal liquefaction. Also establish the

  6. Structured catalyst bed and method for conversion of feed materials to chemical products and liquid fuels

    DOEpatents

    Wang, Yong , Liu; Wei, [Richland, WA

    2012-01-24

    The present invention is a structured monolith reactor and method that provides for controlled Fischer-Tropsch (FT) synthesis. The invention controls mass transport limitations leading to higher CO conversion and lower methane selectivity. Over 95 wt % of the total product liquid hydrocarbons obtained from the monolithic catalyst are in the carbon range of C.sub.5-C.sub.18. The reactor controls readsorption of olefins leading to desired products with a preselected chain length distribution and enhanced overall reaction rate. And, liquid product analysis shows readsorption of olefins is reduced, achieving a narrower FT product distribution.

  7. Understanding the effect of cobalt particle size on Fischer-Tropsch synthesis: surface species and mechanistic studies by SSITKA and kinetic isotope effect.

    PubMed

    Yang, Jia; Tveten, Erik Z; Chen, De; Holmen, Anders

    2010-11-02

    Co/γ-Al(2)O(3) catalysts with particle sizes in the range of 4-15 nm were investigated by isothermal hydrogenation (IH), temperature programmed hydrogenation (TPH), and steady-state isotopic transient kinetic analysis (SSITKA). Kinetic isotope effect experiments were used to probe possible mechanisms on Co/γ-Al(2)O(3) with different particle size. It was found that CO dissociated on Co/γ-Al(2)O(3) catalysts at 210 °C. The total amount of CO(2) formed following the dissociation depends on the cobalt crystal size. O-Co binding energy was found to be highly dependent on the Co metal particle size, whereas similar C-Co binding energy was found on catalysts with different Co particle size. Very strongly bonded carbon and oxygen surface species increased with decreasing particle size and acted as site blocking species in the methanation reaction. SSITKA experiments showed that the intrinsic activity (1/τ(CH(x))) remained constant as the particle size increased from 4 to 15 nm. The number of surface intermediates (N(CH(x))) increased with increasing particle size. The apparent activation energies were found similar for these catalysts, about 85 kJ/mol. D(2)-H(2) switches further confirmed that the particle size did not change the kinetically relevant steps in the reaction. The reactivity of the active sites on the 4 nm particles was the same as those on the 8, 11, and 15 nm particles, and only the number of total available surface active sites was less on the 4 nm particles than on the others.

  8. Study of NiMoS mixed phase from catalyst precursors in residue slurry-bed hydrocracking

    NASA Astrophysics Data System (ADS)

    Du, Juntao; Deng, Wenan; Li, Chuan; Zhang, Zailong; Sun, Qiang; Cao, Xiangpeng; Yang, Tengfei

    2017-03-01

    The evolution and role of NiMoS structures from catalyst precursors on residue hydrocracking was investigated. NiMoS mixed phase played important roles in unsupported catalyst and heavy oil development, such as synergy effect and coke inhibiting. The oil-soluble molybdenum naphthenate and nickel naphthenate were chosen as catalyst precursors. The mixtures of the precursor were compared to those of other monometallic oil-soluble precursor in an effort to evaluate the evolution and role of NiMoS phase in the slurry bed hydrocracking of heavy oil. The presence of NiMoS phase were characterized by X-ray diffraction (XRD), TEM and XPS. The series of tests in the slurry-phase reactor was to confirm the synergy effect of NiMoS mixed phase.

  9. Silylation of a Co/SiO2 catalyst. Characterization and exploitation of the CO hydrogenation reaction.

    PubMed

    Ojeda, Manuel; Pérez-Alonso, Francisco José; Terreros, Pilar; Rojas, Sergio; Herranz, Tirma; López Granados, Manuel; Fierro, José Luis G

    2006-03-28

    Several silylated- and nonsilylated Co/SiO2 catalysts have been prepared by reaction of the surface silanol groups with hexamethyldisilazane (HMDS). These samples have been characterized by means of N2 adsorption isotherms, solid-state nuclear magnetic resonance (29Si and 1H), X-ray photoelectron spectroscopy, thermogravimetric analysis, and diffuse reflectance IR spectroscopy. We have focused on the study of the silylated surface stability at high temperatures and in different atmospheres. The characterization techniques have shown that silica silylation after cobalt impregnation leads to a silylated SiO2 surface composed of hydrophobic Si-(CH3)3 species highly stable up to 600-650 K in both oxidizing and reducing atmospheres. However, X-ray diffraction and temperature-programmed reduction have shown that the hydrophobic nature of the silica surface does not affect the metal dispersion and its reducibility. The materials prepared in this way have been tested as catalysts for the Fischer-Tropsch synthesis reaction. The CO conversion reaction rate increased over the silylated catalyst, probably as a consequence of the higher number of available active sites because water adsorption over the catalyst surface is impeded. However, catalyst deactivation was not affected by the hydrophobic nature of the support, suggesting that carbon deposition is the more probable mechanism of cobalt-based catalyst deactivation during the Fischer-Tropsch synthesis.

  10. Slurry phase iron catalysts for indirect coal liquefaction. First semi-annual progress report, July 5, 1995--January 4, 1996

    SciTech Connect

    Datye, A.K.

    1996-02-08

    Objectives are to study factors controlling attrition resistance of slurry phase Fe catalysts, synthesize novel precipitated catalysts that overcome some of the limitations of current generation catalysts, and study catalyst-binder interactions using model catalysts. A study of Fe/silica (binder) interactions has been started. Study of effects of Cu on reducibility of Fe catalysts showed that small amounts of Cu can facilitate reduction of Fe{sub 2}O{sub 3} to {alpha}-Fe. Work with Nancy Jackson (Sandia) on carbon deposits in Fe F-T catalysts showed good correlation between peak temperature in TPR and the carbon as seen by TEM. Analyses of samples from Dr. Burtron Davis (U. KY) by XRD and TEM showed that the active catalyst contains small crystallites of iron carbide while the deactivated catalyst had significant transformation into large magnetite crystals. It is felt that improper passivation of these catalysts can lead to mis-identification of the phase in working F-T catalysts.

  11. Technology development for cobalt F-T catalysts. Quarterly technical progress report No. 7, April 1, 1994--June 30, 1994

    SciTech Connect

    Singleton, A.H.

    1995-05-31

    This project`s goal is the development of a commercially viable, cobalt-based Fischer-Tropsch (F-T) catalyst for use in a slurry bubble column (SBC) reactor. During the seventh quarter, significant progress in several areas has enabled us to make a number of important conclusions. Preliminary catalyst preparation of 3 batches of a Ru-promoted 20% Co/Al{sub 2}O{sub 3} has confirmed the similarity in catalysts prepared by Energy International and by Calsicat using the same procedure. This similarity was evident in both fixed and SBC reactor studies. All TiO{sub 2}-supported Co catalysts have been found to have poor F-T properties in both the fixed-bed and SBC reactors. These catalysts had been prepared following exactly the procedures given in the Exxon patents. One of the main problems in using TiO{sub 2} as a support is the fact that it has low surface area for supporting a 20 wt % Co catalyst. Another problem is that it does not seem to be robust enough for use in a SBC reactor. Ru promotion of Co/SiO{sub 2} does not have as dramatic an effect on catalyst activity as seen for Co/Al{sub 2}O{sub 3}. However, it does play a major role in maintaining higher activity (factor of 2 in the SBCR) when K is added to Co/Sr/SiO{sub 2}. Zr has been clearly shown by us to significantly enhance the F-T activity of Co/SiO{sub 2}. Such promotion is a basis for many of the Shell cobalt F-T patents. Latest results indicate that Zr also improves the activity of Co/Al{sub 2}O{sub 3}, although the methane selectivity is also slightly elevated. Finally, for our design of a ``benchmark`` Co F- T catalyst, research has now shown using both fixed-bed and SBC reactors that 0.3 wt % K is the optimum amount to use with Ru- promoted 20 wt % Co/Al{sub 2}O{sub 3}. This amount of K greatly improves higher hydrocarbon selectivity without causing an unacceptable loss of activity.

  12. Design of slurry bubble column reactors: novel technique for optimum catalyst size selection contractual origin of the invention

    DOEpatents

    Gamwo, Isaac K [Murrysville, PA; Gidaspow, Dimitri [Northbrook, IL; Jung, Jonghwun [Naperville, IL

    2009-11-17

    A method for determining optimum catalyst particle size for a gas-solid, liquid-solid, or gas-liquid-solid fluidized bed reactor such as a slurry bubble column reactor (SBCR) for converting synthesis gas into liquid fuels considers the complete granular temperature balance based on the kinetic theory of granular flow, the effect of a volumetric mass transfer coefficient between the liquid and the gas, and the water gas shift reaction. The granular temperature of the catalyst particles representing the kinetic energy of the catalyst particles is measured and the volumetric mass transfer coefficient between the gas and liquid phases is calculated using the granular temperature. Catalyst particle size is varied from 20 .mu.m to 120 .mu.m and a maximum mass transfer coefficient corresponding to optimum liquid hydrocarbon fuel production is determined. Optimum catalyst particle size for maximum methanol production in a SBCR was determined to be in the range of 60-70 .mu.m.

  13. Promoted Iron Nanocrystals Obtained via Ligand Exchange as Active and Selective Catalysts for Synthesis Gas Conversion.

    PubMed

    Casavola, Marianna; Xie, Jingxiu; Meeldijk, Johannes D; Krans, Nynke A; Goryachev, Andrey; Hofmann, Jan P; Dugulan, A Iulian; de Jong, Krijn P

    2017-08-04

    Colloidal synthesis routes have been recently used to fabricate heterogeneous catalysts with more controllable and homogeneous properties. Herein a method was developed to modify the surface composition of colloidal nanocrystal catalysts and to purposely introduce specific atoms via ligands and change the catalyst reactivity. Organic ligands adsorbed on the surface of iron oxide catalysts were exchanged with inorganic species such as Na2S, not only to provide an active surface but also to introduce controlled amounts of Na and S acting as promoters for the catalytic process. The catalyst composition was optimized for the Fischer-Tropsch direct conversion of synthesis gas into lower olefins. At industrially relevant conditions, these nanocrystal-based catalysts with controlled composition were more active, selective, and stable than catalysts with similar composition but synthesized using conventional methods, possibly due to their homogeneity of properties and synergic interaction of iron and promoters.

  14. Crystallographic dependence of CO activation on cobalt catalysts: HCP versus FCC.

    PubMed

    Liu, Jin-Xun; Su, Hai-Yan; Sun, Da-Peng; Zhang, Bing-Yan; Li, Wei-Xue

    2013-11-06

    Identifying the structure sensitivity of catalysts in reactions, such as Fischer-Tropsch synthesis from CO and H2 over cobalt catalysts, is an important yet challenging issue in heterogeneous catalysis. Based on a first-principles kinetic study, we find for the first time that CO activation on hexagonal close-packed (HCP) Co not only has much higher intrinsic activity than that of face centered-cubic (FCC) Co but also prefers a different reaction route, i.e., direct dissociation with HCP Co but H-assisted dissociation on the FCC Co. The origin is identified from the formation of various denser yet favorable active sites on HCP Co not available for FCC Co, due to their distinct crystallographic structure and morphology. The great dependence of the activity on the crystallographic structure and morphology of the catalysts revealed here may open a new avenue for better, stable catalysts with maximum mass-specific reactivity.

  15. Fischer–Tropsch Synthesis: Characterization Rb Promoted Iron Catalyst

    SciTech Connect

    Sarkar,A.; Jacobs, G.; Ji, Y.; Hamdeh, H.; Davis, B.

    2008-01-01

    Rubidium promoted iron Fischer-Tropsch synthesis (FTS) catalysts were prepared with two Rb/Fe atomic ratios (1.44/100 and 5/100) using rubidium nitrate and rubidium carbonate as rubidium precursors. Results of catalytic activity and deactivation studies in a CSTR revealed that rubidium promoted catalysts result in a steady conversion with a lower deactivation rate than that of the corresponding unpromoted catalyst although the initial activity of the promoted catalyst was almost half that of the unpromoted catalyst. Rubidium promotion results in lower methane production, and higher CO2, alkene and 1-alkene fraction in FTS products. M{umlt o}ssbauer spectroscopic measurements of CO activated and working catalyst samples indicated that the composition of the iron carbide phase formed after carbidization was -Fe5 C2 for both promoted and unpromoted catalysts. However, in the case of the rubidium promoted catalyst, '-Fe2.2C became the predominant carbidic phase as FTS continued and the overall catalyst composition remained carbidic in nature. In contrast, the carbide content of the unpromoted catalyst was found to decline very quickly as a function of synthesis time. Results of XANES and EXAFS measurements suggested that rubidium was present in the oxidized state and that the compound most prevalent in the active catalyst samples closely resembled that of rubidium carbonate.

  16. Prospects of Fe/MCM-41 as a Catalyst for Hydrocarbon Synthesis

    SciTech Connect

    Cagnoli, Maria V.; Gallegos, Norma G.; Bengoa, Jose F.; Alvarez, Ana M.; Marchetti, Sergio G.; Moreno, Sergio M. J.; Roig, Anna; Mercader, Roberto C.

    2005-04-26

    We report the synthesis of cylindrical nanoparticles of metallic Fe entirely included in MCM-41 pores. Their dimensions are approx.3 nm diameter and approx. 3.8 nm length. We show that a coherent analysis of the results yielded by the various techniques is essential to obtain a catalyst supported on an MCM-41 matrix of {approx_equal} 3 nm average pore diameter, which is active and selective toward olefins. The solids were characterized by low-angle x-ray diffraction, high-resolution transmission electron microscopy, high-resolution scanning transmission electron microscopy equipped with a high-angle annular dark-field, CO chemisorption, volumetric oxidation, and Moessbauer spectroscopy (in controlled atmosphere for the reduced catalysts). Catalytic results in the Fischer-Tropsch synthesis, as well as some unexpected results --like the inhomogeneous pore filling and discontinuous Fe particles-- are also discussed.

  17. Alkali promoted molybdenum (IV) sulfide based catalysts, development and characterization for alcohol synthesis from carbon monoxide and hydrogen

    NASA Astrophysics Data System (ADS)

    Molina, Belinda Delilah

    For more than a century transition metal sulfides (TMS) have been the anchor of hydro-processing fuels and upgrading bitumen and coal in refineries worldwide. As oil supplies dwindle and environmental laws become more stringent, there is a greater need for cleaner alternative fuels and/or synthetic fuels. The depletion of oil reserves and a rapidly increasing energy demand worldwide, together with the interest to reduce dependence on foreign oil makes alcohol production for fuels and chemicals via the Fischer Tropsch synthesis (FTS) very attractive. The original Fischer-Tropsch (FT) reaction is the heart of all gas-to-liquid technologies; it creates higher alcohols and hydrocarbons from CO/H2 using a metal catalyst. This research focuses on the development of alkali promoted MoS2-based catalysts to investigate an optimal synthesis for their assistance in the production of long chain alcohols (via FTS) for their use as synthetic transportation liquid fuels. Properties of catalytic material are strongly affected by every step of the preparation together with the quality of the raw materials. The choice of a laboratory method for preparing a given catalyst depends on the physical and chemical characteristics desired in the final composition. Characterization methods of K0.3/Cs0.3-MoS2 and K0.3 /Cs0.3-Co0.5MoS2 catalysts have been carried out through Scanning Electron Microscopy (SEM), BET porosity and surface analysis, Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD). Various characterization methods have been deployed to correlate FTS products versus crystal and morphological properties of these heterogeneous catalysts. A lab scale gas to liquid system has been developed to evaluate its efficiency in testing FT catalysts for their production of alcohols.

  18. ADVANCED DIAGNOSTIC TECHNIQUES FOR THREE-PHASE SLURRY BUBBLE COLUMN REACTORS (SBCR)

    SciTech Connect

    M.H. Al-Dahhan; M.P. Dudukovic; L.S. Fan

    2001-07-25

    This report summarizes the accomplishment made during the second year of this cooperative research effort between Washington University, Ohio State University and Air Products and Chemicals. The technical difficulties that were encountered in implementing Computer Automated Radioactive Particle Tracking (CARPT) in high pressure SBCR have been successfully resolved. New strategies for data acquisition and calibration procedure have been implemented. These have been performed as a part of other projects supported by Industrial Consortium and DOE via contract DE-2295PC95051 which are executed in parallel with this grant. CARPT and Computed Tomography (CT) experiments have been performed using air-water-glass beads in 6 inch high pressure stainless steel slurry bubble column reactor at selected conditions. Data processing of this work is in progress. The overall gas holdup and the hydrodynamic parameters are measured by Laser Doppler Anemometry (LDA) in 2 inch slurry bubble column using Norpar 15 that mimic at room temperature the Fischer Tropsch wax at FT reaction conditions of high pressure and temperature. To improve the design and scale-up of bubble column, new correlations have been developed to predict the radial gas holdup and the time averaged axial liquid recirculation velocity profiles in bubble columns.

  19. Attrition Resistant Iron-Based Catalysts For F-T SBCRs

    SciTech Connect

    Adeyinka A. Adeyiga

    2006-01-31

    The Fischer-Tropsch (F-T) reaction provides a way of converting coal-derived synthesis gas (CO+ H{sub 2}) to liquid fuels. Since the reaction is highly exothermic, one of the major problems in control of the reaction is heat removal. Recent work has shown that the use of slurry bubble column reactors (SBCRs) can largely solve this problem. The use of iron-(FE) based catalysts is attractive not only due to their low cost and ready availability, but also due to their high water-gas shift activity which makes it possible to use these catalysts with low H{sub 2}/CO ratios. However, a serious problem with the use of Fe catalysts in a SBCR is their tendency to undergo attrition. This can cause fouling/plugging of downstream filters and equipment; makes the separation of catalyst from the oil/wax product very difficult, if not impossible; and results in a steady loss of catalyst from the reactor. Under a previous Department of Energy (DOE)/University Research Grant (UCR) grant, Hampton University reported, for the first time, the development of demonstrably attrition-resistant Fe F-T synthesis catalysts having good activity, selectivity, and attrition resistance. These catalysts were prepared by spray drying Fe catalysts with potassium (K), copper (Cu), and silica (SiO{sub 2}) as promoters. SiO{sub 2} was also used as a binder for spray drying. These catalysts were tested for activity and selectivity in a laboratory-scale fixed-bed reactor. Fundamental understanding of attrition is being addressed by incorporating suitable binders into the catalyst recipe. This has resulted in the preparation of a spray dried HPR-43 catalyst having average particle size (aps) of 70 {micro}m with high attrition resistance. This HPR-43 attrition resistant, active and selective catalyst gave 95% CO conversion through 125 hours of testing in a fixed-bed at 270 C, 1.48 MPa, H{sub 2}/CO=0.67 and 2.0 NL/g-cat/h with C{sub 5+} selectivity of >78% and methane selectivity of less than 5% at an

  20. Thermal stability and hcp-fcc allotropic transformation in supported Co metal catalysts probed near operando by ferromagnetic NMR.

    PubMed

    Andreev, Andrey S; d'Espinose de Lacaillerie, Jean-Baptiste; Lapina, Olga B; Gerashenko, Alexander

    2015-06-14

    Despite the fact that cobalt based catalysts are used at the industrial scale for Fischer-Tropsch synthesis, it is not yet clear which cobalt metallic phase is actually at work under operando conditions and what is its state of dispersion. As it turns out, the different phases of metallic cobalt, fcc and hcp, give rise to distinct ferromagnetic nuclear magnetic resonance. Furthermore, within one Co metal particle, the occurrence of several ferromagnetic domains of limited sizes can be evidenced by the specific resonance of Co in multi-domain particles. Consequently, by ferromagnetic NMR, one can follow quantitatively the sintering and phase transitions of dispersed Co metal particles in supported catalysts under near operando conditions. The minimal size probed by ferromagnetic Co NMR is not precisely known but is considered to be in the order of 10 nm for supported Co particles at room temperature and increases to about 35 nm at 850 K. Here, in Co metal Fischer-Tropsch synthesis catalysts supported on β-SiC, the resonances of the fcc multi-domain, fcc single-domain and hcp Co were clearly distinguished. A careful rationalization of their frequency and width dependence on temperature allowed a quantitative analysis of the spectra in the temperature range of interest, thus reflecting the state of the catalysts under near operando conditions that is without the uncertainty associated with prior quenching. The allotropic transition temperature was found to start at 600-650 K, which is about 50 K below the bulk transition temperature. The phase transition was fully reversible and a significant part of the hcp phase was found to be stable up to 850 K. This anomalous behavior that was observed without quenching might prove to be crucial to understand and model active species not only in catalysts but also in battery materials.

  1. Conversion of syngas to light olefins over silicalite-1 supported iron and cobalt catalysts: Effects of manganese addition

    SciTech Connect

    Das, D.; Ravichandran, G.; Chakrabarty, D.K.

    1996-10-01

    As the demand for light (C2-C4) olefins, an important raw materials for a number of chemical industries, is ever increasing considerable attention is now being paid to the design of suitable catalysts with high selectivity for small chain olefins. Although Fischer-Tropsch synthesis yields a wide spectrum of products from methane to waxes it is possible to restrict the chain growth to a few carbon atoms by containing the active metal panicles inside the small pores of a suitable support like zeolite. The nature of the zeolite support also has a strong influence on the product selectivity due to secondary reactions. This paper discusses the results of syngas conversion to light olefins over iron and cobalt catalysts supported on silicalite-1. Effect of the addition of manganese which is known to improve the selectivity to light olefins is also discussed.

  2. Continuous bench-scale slurry catalyst testing direct coal liquefaction rawhide sub-bituminous coal

    SciTech Connect

    Bauman, R.F.; Coless, L.A.; Davis, S.M.

    1995-12-31

    In 1992, the Department of Energy (DOE) sponsored research to demonstrate a dispersed catalyst system using a combination of molybdenum and iron precursors for direct coal liquefaction. This dispersed catalyst system was successfully demonstrated using Black Thunder sub-bituminous coal at Wilsonville, Alabama by Southern Electric International, Inc. The DOE sponsored research continues at Exxon Research and Development Laboratories (ERDL). A six month continuous bench-scale program using ERDL`s Recycle Coal Liquefaction Unit (RCLU) is planned, three months in 1994 and three months in 1995. The initial conditions in RCLU reflect experience gained from the Wilsonville facility in their Test Run 263. Rawhide sub-bituminous coal which is similar to the Black Thunder coal tested at Wilsonville was used as the feed coal. A slate of five dispersed catalysts for direct coal liquefaction of Rawhide sub-bituminous coal has been tested. Throughout the experiments, the molybdenum addition rate was held constant at 100 wppm while the iron oxide addition rate was varied from 0.25 to 1.0 weight percent (dry coal basis). This report covers the 1994 operations and accomplishments.

  3. Catalytic conversion wood syngas to synthetic aviation turbine fuels over a multifunctional catalyst.

    PubMed

    Yan, Qiangu; Yu, Fei; Liu, Jian; Street, Jason; Gao, Jinsen; Cai, Zhiyong; Zhang, Jilei

    2013-01-01

    A continuous process involving gasification, syngas cleaning, and Fischer-Tropsch (FT) synthesis was developed to efficiently produce synthetic aviation turbine fuels (SATFs). Oak-tree wood chips were first gasified to syngas over a commercial pilot plant downdraft gasifier. The raw wood syngas contains about 47% N(2), 21% CO, 18% H(2), 12% CO(2,) 2% CH(4) and trace amounts of impurities. A purification reaction system was designed to remove the impurities in the syngas such as moisture, oxygen, sulfur, ammonia, and tar. The purified syngas meets the requirements for catalytic conversion to liquid fuels. A multi-functional catalyst was developed and tested for the catalytic conversion of wood syngas to SATFs. It was demonstrated that liquid fuels similar to commercial aviation turbine fuels (Jet A) was successfully synthesized from bio-syngas. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Supported iron nanoparticles as catalysts for sustainable production of lower olefins.

    PubMed

    Torres Galvis, Hirsa M; Bitter, Johannes H; Khare, Chaitanya B; Ruitenbeek, Matthijs; Dugulan, A Iulian; de Jong, Krijn P

    2012-02-17

    Lower olefins are key building blocks for the manufacture of plastics, cosmetics, and drugs. Traditionally, olefins with two to four carbons are produced by steam cracking of crude oil-derived naphtha, but there is a pressing need for alternative feedstocks and processes in view of supply limitations and of environmental issues. Although the Fischer-Tropsch synthesis has long offered a means to convert coal, biomass, and natural gas into hydrocarbon derivatives through the intermediacy of synthesis gas (a mixture of molecular hydrogen and carbon monoxide), selectivity toward lower olefins tends to be low. We report on the conversion of synthesis gas to C(2) through C(4) olefins with selectivity up to 60 weight percent, using catalysts that constitute iron nanoparticles (promoted by sulfur plus sodium) homogeneously dispersed on weakly interactive α-alumina or carbon nanofiber supports.

  5. Synthesis and characterization of catalysts for the selective transformation of biomass-derived materials

    NASA Astrophysics Data System (ADS)

    Ghampson, Isaac Tyrone

    The experimental work in this thesis focuses on generating catalysts for two intermediate processes related to the thermal conversion of lignocellulosic biomass: the synthesis and characterization of mesoporous silica supported cobalt catalysts for the Fischer-Tropsch reaction, and an exploration of the reactivity of bulk and supported molybdenum-based nitride catalysts for the hydrodeoxygenation (HDO) of guaiacol, a lignin model compound. The first section of the work details the synthesis of a series of silica-supported cobalt Fischer-Tropsch catalysts with pore diameters ranging from 2-23 nm. Detailed X-ray diffraction measurements were used to determine the composition and particle diameters of the metal fraction, analyzed as a three-phase system containing Cofcc, Cohcp and CoO particles. Catalyst properties were determined at three stages in catalyst history: (1) after the initial calcination step to thermally decompose the catalyst precursor into Co3O4, (2) after the hydrogen reduction step to activate the catalyst to Co and (3) after the FT reaction. From the study, it was observed that larger pore diameters supported higher turnover frequency; smaller pore diameters yielded larger mole fraction of CoO; XRD on post-reduction and post-FTS catalyst samples indicated significant changes in dispersivity after reduction. In the next section, the catalytic behaviors of unsupported, activated carbon-, alumina-, and SBA-15 mesoporous silica-supported molybdenum nitride catalysts were evaluated for the hydrodeoxygenation of guaiacol (2-methoxy phenol) at 300°C and 5 MPa. The nitride catalysts were prepared by thermal decomposition of bulk and supported ammonium heptamolybdate to form MoO 3 followed by nitridation in either flowing ammonia or a nitrogen/hydrogen mixture. The catalytic properties were strongly affected by the nitriding and purging treatment as well as the physical and chemical properties of support. The overall reaction was influenced by the

  6. Metal-support interaction on cobalt based FT catalysts - a DFT study of model inverse catalysts.

    PubMed

    van Heerden, Tracey; van Steen, Eric

    2017-04-28

    It is challenging to isolate the effect of metal-support interactions on catalyst reaction performance. In order to overcome this problem, inverse catalysts can be prepared in the laboratory and characterized and tested at relevant conditions. Inverse catalysts are catalysts where the precursor to the catalytically active phase is bonded to a support-like ligand. We can then view the metal-support interaction as a ligand interaction with the support acting as a supra-molecular ligand. Importantly, laboratory studies have shown that these ligands are still present after reduction of the catalyst. By varying the quantity of these ligands present on the surface, insight into the positive effect SMSI have during a reaction is gained. Here, we present a theoretical study of mono-dentate alumina support based ligands, adsorbed on cobalt surfaces. We find that the presence of the ligand may significantly affect the morphology of a cobalt crystallite. With Fischer-Tropsch synthesis in mind, the CO dissociation is used as a probe reaction, with the ligand assisting the dissociation, making it feasible to dissociate CO on the dense fcc Co(111) surface. The nature of the interaction between the ligand and the probe molecule is characterized, showing that the support-like ligands' metal centre is directly interacting with the probe molecule.

  7. Deactivation by carbon of iron catalysts for indirect liquefaction

    SciTech Connect

    Bartholomew, C.H.

    1991-01-10

    Although promoted cobalt and iron catalysts for Fischer-Tropsch (FT) synthesis of gasoline feedstock were first developed more than three decades ago, a major technical problem still limiting the commercial use of these catalysts today is carbon deactivation. This report describes recent progress in a fundamental, three-year investigation of carbon formation and its effects on the activity and selectivity of promoted iron catalysts for FT synthesis, the objectives of which are to: determine rates and mechanisms of carbon deactivation of unsupported Fe and Fe/K catalysts during CO hydrogenation over a range of CO concentrations, CO:H{sub 2} ratios, and temperatures; and model the rates of deactivation of the same catalysts in fixed-bed reactors. To accomplish the above objectives, the project is divided into the following tasks: (1) determine the kinetics of reaction and of carbon deactivation during CO hydrogenation on Fe and Fe/K catalysts coated on monolith bodies. (2) Determine the reactivities and types of carbon deposited during reaction on the same catalysts from temperature-programmed-surface-reaction spectroscopy (TPSR) and transmission electron microscopy (TEM). Determine the types of iron carbides formed at various temperatures and H{sub 2}/CO ratios using x-ray diffraction and Moessbauer spectroscopy. (3) Develop mathematical deactivation models which include heat and mass transport contributions for FT synthesis is packed-bed reactors. Progress to date is described. 48 refs., 3 figs., 1 tab.

  8. Development of catalysts for the utilization of carbon monoxide. Final report, May 1, 1981-December 31, 1982

    SciTech Connect

    Kyba, E.P.; Pettit, R.

    1983-01-01

    Research was conducted ..mu..-methylene-dimella species and on heterogeneously catalyzed reactions. Fe(CO)/sub 8//sup 2 -/ reacts with methylene iodide to give the parent bridging methylene complex which reacts with olefins and acetylenes in heterogeneous Fischer-Tropsch reactions. The formation of hydrocarbons was studied. Alcohols were studied as substrates for Fischer-Tropsch reactions. (DLC)

  9. Active phase distribution changes within a catalyst particle during Fischer–Tropsch synthesis as revealed by multi-scale microscopy

    DOE PAGES

    Cats, K. H.; Andrews, J. C.; Stephan, O.; ...

    2016-02-16

    In this study, the Fischer-Tropsch synthesis (FTS) reaction is one of the most promising processes to convert alternative energy sources, such as natural gas, coal or biomass, into liquid fuels and other high-value products. Despite its commercial implementation, we still lack fundamental insights into the various deactivation processes taking place during FTS. In this work, a combination of three methods for studying single catalyst particles at different length scales has been developed and applied to study the deactivation of Co/TiO2 Fischer-Tropsch synthesis (FTS) catalysts. By combining transmission X-ray microscopy (TXM), scanning transmission X-ray microscopy (STXM) and scanning transmission electron microscopy-electronmore » energy loss spectroscopy (STEM-EELS) we visualized changes in the structure, aggregate size and distribution of supported Co nanoparticles that occur during FTS. At the microscale, Co nanoparticle aggregates are transported over several μm leading to a more homogeneous Co distribution, while at the nanoscale Co forms a thin layer of ~1-2 nm around the TiO2 support. The formation of the Co layer is the opposite case to the “classical” strong metal-support interaction (SMSI) in which TiO2 surrounds the Co, and is possibly related to the surface oxidation of Co metal nanoparticles in combination with coke formation. In other words, the observed migration and formation of a thin CoOx layer are similar to a previously discussed reaction-induced spreading of metal oxides across a TiO2 surface.« less

  10. Active phase distribution changes within a catalyst particle during Fischer–Tropsch synthesis as revealed by multi-scale microscopy

    SciTech Connect

    Cats, K. H.; Andrews, J. C.; Stephan, O.; March, K.; Karunakaran, C.; Meirer, F.; de Groot, F. M. F.; Weckhuysen, B. M.

    2016-02-16

    In this study, the Fischer-Tropsch synthesis (FTS) reaction is one of the most promising processes to convert alternative energy sources, such as natural gas, coal or biomass, into liquid fuels and other high-value products. Despite its commercial implementation, we still lack fundamental insights into the various deactivation processes taking place during FTS. In this work, a combination of three methods for studying single catalyst particles at different length scales has been developed and applied to study the deactivation of Co/TiO2 Fischer-Tropsch synthesis (FTS) catalysts. By combining transmission X-ray microscopy (TXM), scanning transmission X-ray microscopy (STXM) and scanning transmission electron microscopy-electron energy loss spectroscopy (STEM-EELS) we visualized changes in the structure, aggregate size and distribution of supported Co nanoparticles that occur during FTS. At the microscale, Co nanoparticle aggregates are transported over several μm leading to a more homogeneous Co distribution, while at the nanoscale Co forms a thin layer of ~1-2 nm around the TiO2 support. The formation of the Co layer is the opposite case to the “classical” strong metal-support interaction (SMSI) in which TiO2 surrounds the Co, and is possibly related to the surface oxidation of Co metal nanoparticles in combination with coke formation. In other words, the observed migration and formation of a thin CoOx layer are similar to a previously discussed reaction-induced spreading of metal oxides across a TiO2 surface.

  11. Deactivation by carbon of iron catalysts for indirect liquefaction

    SciTech Connect

    Bartholomew, C.H.

    1990-10-11

    This report describes recent progress in a fundamental, three-year investigation of carbon formation and its effects on the activity and selectivity of promoted iron catalysts for Fischer-Tropsch (FT) synthesis, the objectives of which are: determine rates and mechanisms of carbon deactivation of unsupported Fe and Fe/K catalysts during CO hydrogenation over a range of CO concentrations, CO:H{sub 2} ratios, and temperatures; model the rates of deactivation of the same catalysts in fixed-bed reactors. During the thirteenth quarter design of software for a computer-automated reactor system to be used in the kinetic and deactivation studies was continued. Further progress was made toward the completion of the control language, control routines, and software for operating this system. Progress was also made on the testing of the system hardware and software. H{sub 2} chemisorption capacities and activity selectivity data were also measured for three iron catalysts promoted with 1% alumina. 47 refs., 8 figs., 1 tab.

  12. A review of dry (CO2) reforming of methane over noble metal catalysts.

    PubMed

    Pakhare, Devendra; Spivey, James

    2014-11-21

    Dry (CO2) reforming of methane (DRM) is a well-studied reaction that is of both scientific and industrial importance. This reaction produces syngas that can be used to produce a wide range of products, such as higher alkanes and oxygenates by means of Fischer-Tropsch synthesis. DRM is inevitably accompanied by deactivation due to carbon deposition. DRM is also a highly endothermic reaction and requires operating temperatures of 800-1000 °C to attain high equilibrium conversion of CH4 and CO2 to H2 and CO and to minimize the thermodynamic driving force for carbon deposition. The most widely used catalysts for DRM are based on Ni. However, many of these catalysts undergo severe deactivation due to carbon deposition. Noble metals have also been studied and are typically found to be much more resistant to carbon deposition than Ni catalysts, but are generally uneconomical. Noble metals can also be used to promote the Ni catalysts in order to increase their resistance to deactivation. In order to design catalysts that minimize deactivation, it is necessary to understand the elementary steps involved in the activation and conversion of CH4 and CO2. This review will cover DRM literature for catalysts based on Rh, Ru, Pt, and Pd metals. This includes the effect of these noble metals on the kinetics, mechanism and deactivation of these catalysts.

  13. Effects of K and Pt promoters on the performance of cobalt catalyst supported on CNTs

    SciTech Connect

    Zabidi, Noor Asmawati Mohd; Ali, Sardar; Subbarao, Duvvuri

    2014-10-24

    This paper presents a comparative study on the effects of incorporation of potassium (K) and platinum (Pt) as promoters on the physicochemical properties of cobalt catalyst. The catalyst was prepared by a wet impregnation method on a CNTs support. Samples were characterized using transmission electron microscopy (TEM), H{sub 2}-temperature-programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS) techniques. Fischer-Tropsch Synthesis (FTS) was carried out in a fixed-bed microreactor at 543 K and 1 atm, with H{sub 2}/CO = 2v/v and space velocity, SV of 12 L/g.h for 5 hours. The K-promoted and Pt-promoted Co catalysts have different physicochemical properties and catalytic performances compared to that of the un-promoted Co catalyst. XPS analysis revealed that K and Pt promoters induced electronic modifications as exhibited by the shifts in the Co binding energies. Incorporation of 0.06 wt% K and 0.06 wt% Pt in Co/CNTs catalyst resulted in an increase in the CO conversion and C{sub 5+} selectivity and a decrease in methane selectivity. Potassium was found to be a better promoter for Co/CNTs catalyst compared to platinum.

  14. Effects of K and Pt promoters on the performance of cobalt catalyst supported on CNTs

    NASA Astrophysics Data System (ADS)

    Zabidi, Noor Asmawati Mohd; Ali, Sardar; Subbarao, Duvvuri

    2014-10-01

    This paper presents a comparative study on the effects of incorporation of potassium (K) and platinum (Pt) as promoters on the physicochemical properties of cobalt catalyst. The catalyst was prepared by a wet impregnation method on a CNTs support. Samples were characterized using transmission electron microscopy (TEM), H2-temperature-programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS) techniques. Fischer-Tropsch Synthesis (FTS) was carried out in a fixed-bed microreactor at 543 K and 1 atm, with H2/ CO = 2v / v and space velocity, SV of 12 L/g.h for 5 hours. The K-promoted and Pt-promoted Co catalysts have different physicochemical properties and catalytic performances compared to that of the un-promoted Co catalyst. XPS analysis revealed that K and Pt promoters induced electronic modifications as exhibited by the shifts in the Co binding energies. Incorporation of 0.06 wt% K and 0.06 wt% Pt in Co/CNTs catalyst resulted in an increase in the CO conversion and C5+ selectivity and a decrease in methane selectivity. Potassium was found to be a better promoter for Co/CNTs catalyst compared to platinum.

  15. The Effect of Copper Addition on the Activity and Stability of Iron-Based CO₂ Hydrogenation Catalysts.

    PubMed

    Bradley, Matthew J; Ananth, Ramagopal; Willauer, Heather D; Baldwin, Jeffrey W; Hardy, Dennis R; Williams, Frederick W

    2017-09-20

    Iron-based CO₂ catalysts have shown promise as a viable route to the production of olefins from CO₂ and H₂ gas. However, these catalysts can suffer from low conversion and high methane selectivity, as well as being particularly vulnerable to water produced during the reaction. In an effort to improve both the activity and durability of iron-based catalysts on an alumina support, copper (10-30%) has been added to the catalyst matrix. In this paper, the effects of copper addition on the catalyst activity and morphology are examined. The addition of 10% copper significantly increases the CO₂ conversion, and decreases methane and carbon monoxide selectivity, without significantly altering the crystallinity and structure of the catalyst itself. The FeCu/K catalysts form an inverse spinel crystal phase that is independent of copper content and a metallic phase that increases in abundance with copper loading (>10% Cu). At higher loadings, copper separates from the iron oxide phase and produces metallic copper as shown by SEM-EDS. An addition of copper appears to increase the rate of the Fischer-Tropsch reaction step, as shown by modeling of the chemical kinetics and the inter- and intra-particle transport of mass and energy.

  16. Fischer-Tropsch Synthetic Fuel Evaluations HMMWV Test Track Evaluation

    DTIC Science & Technology

    2009-09-01

    area code) Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39.18 v EXECUTIVE SUMMARY This test utilizes a HMMWV in comparing four...C-L053. The U.S. Army Tank- Automotive RD&E Center, Force Projection Technologies, Warren, Michigan administered the project. Mr. Luis Villahermosa...National Automotive Center served as project technical monitors. The authors would also like to recognize the contribution of Jeff Sellers for his

  17. VLE MEASUREMENTS FOR ASYMMETRIC MIXTURES OF FISCHER-TROPSCH HYDROCARBONS

    SciTech Connect

    Mark C. Thies

    2004-01-12

    The ability to model the thermodynamic phase behavior of long-chain and short-chain alkane mixtures is of considerable industrial and theoretical interest. However, attempts to accurately describe the phase behavior of what we call asymmetric mixtures of hydrocarbons (AMoHs) have met with only limited success. Vapor-liquid equilibrium (VLE) data are surprisingly scarce, and the limited data that are available suggest that cubic equations of state may not be capable of fitting (much less predicting) the phase behavior of AMoHs. The following tasks, which address the problems described above, were accomplished during the one-year period of this Phase I UCR grant: (1) A continuous-flow apparatus was modified for the measurement of AMoHs and used to measure VLE for propane + hexadecane mixtures at temperatures from 473 to 626 K and pressures up to the mixture critical pressures of about 100 bar. (2) The extent to which cubic vs. modern, statistical mechanics-based equations of state (EoS) are applicable to AMoHs was evaluated. Peng-Robinson (PR) was found to be a surprisingly accurate equation for fitting AMoHs, but only if its pure component parameters were regressed to liquid densities and vapor pressures. However, even this form of PR was still not a predictive equation, as there was a significant variation of kij with temperature. In spite of its deficiencies in terms of vapor-phase predictions and modeling of the critical region, PC-SAFT was found to be the most appropriate EoS for truly predicting the phase behavior of highly asymmetric mixtures of alkanes. (3) Finally, a dense-gas extraction (DGE) apparatus was designed and constructed for the fractionation of F-T waxes into cuts of pure oligomers. Such oligomers are needed in g-sized quantities to perform VLE measurements with long-chain alkanes with carbon numbers greater than 40. The dense gas and the solute mixture to be extracted are contacted in a packed column that has a separation power significantly greater than what can be achieved in one equilibrium stage. Thus, wax oligomer purities are expected to be much better than what can be obtained by conventional supercritical extraction processes.

  18. Oxygenates formed from ethanol during Fischer-Tropsch synthesis

    SciTech Connect

    Tau, L.; Robinson, R.; Ross, R.D.; Davis, B.H.

    1987-06-01

    Addition of /sup 14/C labeled ethanol to a syngas feed (H/sub 2//CO = 0.78) results in dehydrogenation to acetaldehyde to establish an equilibrium ratio of alcohol to aldehyde. In addition, ethyl acetate and acetal have been identified, using both gas chromatographic-mass spectroscopic and gas chromatographic-infrared techniques, as significant reaction products that, because of /sup 14/C content, are shown to be derived from the added ethanol. Alcohols with greater than two carbons are also formed from ethanol; their relative concentrations suggest that aldol condensation of acetaldehyde contributes to the overall reaction mechanism. In the stirred autoclave reactor, more ethanol is converted to other oxygenates than is incorporated into higher carbon number hydrocarbons; however, ethanol is a chain growth initiator. The data is consistent with significant accumulation of ethanol in the reactor above the concentration in the gas feed when octacosane is used as a solvent with a 10 wt% Fe on high surface area (700 m/sup 2//g) silica support. 21 references.

  19. Microscopic Understanding of Fischer-Tropsch Synthesis on Ruthenium

    SciTech Connect

    Chavez, Donna L.

    2014-10-01

    Total energy calculations and scanning tunneling microscope (STM) image simulations were conducted in an effort to interpret new experimental images of CO and H adsorbed on the closepacked surface of ruthenium metal. The images are remarkable in suggesting that the adsorbed species are intermixed, plausibly accounting for the superior catalytic activity of this metal in forming hydrocarbons. Insight was gained over the short duration of the project, but a more accurate method of simulating images will be required before contact between theory and experiment points to a final result.

  20. Studies on KIT-6 Supported Cobalt Catalyst for Fischer–Tropsch Synthesis

    SciTech Connect

    Gnanamani, M.; Jacobs, G; Graham, U; Ma, W; Pendyala, V; Ribeiro, M; Davis, B

    2010-01-01

    KIT-6 molecular sieve was used as a support to prepare cobalt catalyst for Fischer-Tropsch synthesis (FTS) using an incipient wetness impregnation method to produce cobalt loadings of 15 and 25 wt%. The catalysts were characterized by BET surface area, X-ray diffraction, scanning transmission election microscopy (STEM), extended X-ray absorption fine spectroscopy and X-ray absorption near edge spectroscopy. The catalytic properties for FTS were evaluated using a 1L CSTR reactor. XRD, pore size distribution, and STEM analysis indicate that the KIT-6 mesostructure remains stable during and after cobalt impregnation and tends to form smaller cobalt particles, probably located inside the mesopores. The mesoporous KIT-6 exhibited a slightly higher cobalt dispersion compared to amorphous SiO{sub 2} supported catalyst. With the higher Co loading (25 wt%) on KIT-6, partial structural collapse was observed after the FTS reaction. Compared to an amorphous SiO{sub 2} supported cobalt catalyst, KIT-6 supported cobalt catalyst displayed higher methane selectivity at a similar Co loading, likely due to diffusion effects.

  1. Development of a catalyst for conversion of syngas-derived materials to isobutylene. Technical progress report No. 4, January 1, 1992--March 30, 1992

    SciTech Connect

    Gajda, G.J.

    1993-09-10

    The main goal of this contract is to develop a catalyst and technology that will produce iC{sub 4=} directly from coal-derived syngas and that is capable of using a lower H{sub 2}/CO ratio (0.5 to 1.0). The research will identify and optimize the key catalyst and process characteristics that give improved performance for CO conversion by a non-Fischer-Tropsch process. This report, which is the Technical Progress Report No. 4 for contract DE-AC22-91PC90042, covers the testing of various ZrO{sub 2}-based catalyst systems designed to examine the effects of catalyst preparation and process variables, especially the H{sub 2}/CO ratio. Testing of sol-gel ZrO{sub 2} catalysts with 1 or 2% cesium (Cs) addition indicates decreased stability at a H{sub 2}:CO ratio of 0.5. The addition of cobalt (Co) or copper (Cu) to the base ZrO{sub 2} catalyst results in a small activity gain, but a selectivity loss. This gain in Cu catalyst activity is mostly due to increased methane production. The Co catalyst shifts selectivity toward saturated products. The addition of water to the feed stream had a beneficial effect on stability. The addition of a basic clay had no effect on the activity or selectivity.

  2. Design and modification of zeolite capsule catalyst, a confined reaction field, and its application in one-step isoparaffin synthesis from syngas

    SciTech Connect

    Guohui Yang; Jingjiang He; Yi Zhang; Yoshiharu Yoneyama; Yisheng Tan; Yizhuo Han; Tharapong Vitidsant; Noritatsu Tsubaki

    2008-05-15

    Four kinds of zeolite capsule catalyst with different crystallization conditions were prepared and utilized for the middle isoparaffin direct synthesis via Fischer-Tropsch synthesis (FTS) reaction. Characterization results exhibited that these capsule catalysts had a compact, integral H-ZSM-5 shell. In FTS reactions on these zeolite capsule catalysts, hydrocarbons of C11+ were totally suppressed, accompanied by a sharp anti-Anderson-Schultz-Flory (ASF) law product distribution. The selectivity of light isoparaffin was improved obviously, but with the increase of the olefin's selectivity. Two-stage isoparaffin synthesis reaction, using the combination of zeolite capsule catalyst with hydrogenation catalyst of Pd/SiO{sub 2} in a single reactor as dual-bed catalyst, was also conducted for converting the residual olefins produced by the single zeolite capsule catalyst. Dependent on the palladium role of hydrogenation and hydrogen spillover, almost all the olefins effused from the first stage of zeolite capsule catalyst were hydrogenated, mostly converted to isoparaffin. The selectivity of isoparaffin in the final products was increased markedly as expected. 10 refs., 7 figs., 2 tabs.

  3. CATALYTIC RECOMBINATION OF RADIOLYTIC GASES IN THORIUM OXIDE SLURRIES

    DOEpatents

    Morse, L.E.

    1962-08-01

    A method for the coinbination of hydrogen and oxygen in aqueous thorium oxide-uranium oxide slurries is described. A small amount of molybdenum oxide catalyst is provided in the slurry. This catalyst is applicable to the recombination of hydrogen and/or deuterium and oxygen produced by irradiation of the slurries in nuclear reactors. (AEC)

  4. Stable carbonous catalyst particles and method for making and utilizing same

    DOEpatents

    Ganguli, Partha S.; Comolli, Alfred G.

    2005-06-14

    Stable carbonous catalyst particles composed of an inorganic catalytic metal/metal oxide powder and a carbonaceous binder material are formed having a basic inner substantially uniform-porous carbon coating of the catalytic powder, and may include an outer porous carbon coating layer. Suitable inorganic catalytic powders include zinc-chromite (ZnO/Cr.sub.2 03) and suitable carbonaceous liquid binders having molecular weight of 200-700 include partially polymerized furfuryl alcohol, which are mixed together, shaped and carbonized and partially oxidized at elevated temperature. Such stable carbonous catalyst particles such as 0.020-0.100 inch (0.51-2.54 mm) diameter extrudates, have total carbon content of 2-25 wt. % and improved crush strength of 1.0-5 1b/mn, 50-300 m.sup.2 /g surface area, and can be advantageously utilized in fixed bed or ebullated/fluidized bed reactor operations. This invention also includes method steps for making the stable carbonous catalyst particles having improved particle strength and catalytic activity, and processes for utilizing the active stable carbonous carbon-coated catalysts such as for syn-gas reactions in ebullated/fluidized bed reactors for producing alcohol products and Fischer-Tropsch synthesis liquid products.

  5. Fischer–Tropsch synthesis: Effect of ammonia on supported cobalt catalysts

    DOE PAGES

    Pendyala, Venkat Ramana Rao; Jacobs, Gary; Bertaux, Clement; ...

    2016-02-22

    The effect of ammonia in syngas on the performance of various supported cobalt catalysts (i.e., Al2O3, TiO2 and SiO2) was investigated during Fischer-Tropsch synthesis (FTS) using a continuously stirred tank reactor (CSTR). The addition of ammonia (10 ppmv NH3) caused a significant deactivation for all supported cobalt catalysts, but the rate of deactivation was higher for the silica-supported catalysts relative to the alumina and titania-supported catalysts used in this work. Ammonia addition had a positive effect on product selectivity (i.e., lower light gas products and higher C5+) for alumina and titania-supported catalysts compared to ammonia free conditions, whereas, the additionmore » of ammonia increased lighter hydrocarbon (C1-C4) products and decreased higher hydrocarbon (C5+) selectivity compared to ammonia-free synthesis conditions for the silica-supported catalyst. For alumina and titania-supported catalysts, the activity almost recovered with mild in-situ hydrogen treatment of the ammonia exposed catalysts. For the silica-supported catalyst, the loss of activity is somewhat irreversible (i.e., cannot be regained after the mild hydrogen treatment). Addition of ammonia led to a significant loss in BET surface area and changes in pore diameter (consistent with pore collapse of a fraction of pores into the microporous range as described in the literature), as well as formation of catalytically inactive cobalt support compounds for the silica-supported catalyst. On the other hand, the pore characteristics of alumina and titania-supported catalysts were not significantly changed. In conclusion, XANES results of the ammonia exposed silica-supported catalysts further confirm the formation of cobalt-support compounds (cobalt silicates).« less

  6. Fischer–Tropsch synthesis: Effect of ammonia on supported cobalt catalysts

    SciTech Connect

    Pendyala, Venkat Ramana Rao; Jacobs, Gary; Bertaux, Clement; Khalid, Syed; Davis, Burtron H.

    2016-02-22

    The effect of ammonia in syngas on the performance of various supported cobalt catalysts (i.e., Al2O3, TiO2 and SiO2) was investigated during Fischer-Tropsch synthesis (FTS) using a continuously stirred tank reactor (CSTR). The addition of ammonia (10 ppmv NH3) caused a significant deactivation for all supported cobalt catalysts, but the rate of deactivation was higher for the silica-supported catalysts relative to the alumina and titania-supported catalysts used in this work. Ammonia addition had a positive effect on product selectivity (i.e., lower light gas products and higher C5+) for alumina and titania-supported catalysts compared to ammonia free conditions, whereas, the addition of ammonia increased lighter hydrocarbon (C1-C4) products and decreased higher hydrocarbon (C5+) selectivity compared to ammonia-free synthesis conditions for the silica-supported catalyst. For alumina and titania-supported catalysts, the activity almost recovered with mild in-situ hydrogen treatment of the ammonia exposed catalysts. For the silica-supported catalyst, the loss of activity is somewhat irreversible (i.e., cannot be regained after the mild hydrogen treatment). Addition of ammonia led to a significant loss in BET surface area and changes in pore diameter (consistent with pore collapse of a fraction of pores into the microporous range as described in the literature), as well as formation of catalytically inactive cobalt support compounds for the silica-supported catalyst. On the other hand, the pore characteristics of alumina and titania-supported catalysts were not significantly changed. In conclusion, XANES results of the ammonia exposed silica-supported catalysts further confirm the formation of cobalt-support compounds (cobalt silicates).

  7. Effect of Bimetallic Ni-Cr Catalysts for Steam-CO2 Reforming of Methane at High Pressure.

    PubMed

    Choi, Bong Kwan; Park, Yoon Hwa; Moon, Dong Ju; Park, Nam Cook; Kim, Young Chul

    2015-07-01

    The present work was to carry out the development of high performance Ni-based catalyst for Steam-CO2 reforming of methane (SCR) which is suitable for Fischer-Tropsch synthesis of GTL- FPSO (floating, production, storage and offloading) process. The bimetallic Ni-Cr catalysts were prepared by co-impregnation method. The Ni and Cr loading amount were fixed at 12 wt% and 3~7 wt%, respectively. The catalytic reaction was conducted at 900 °C and 20 bar with reactant feed ratio of CH4:CO2:H2O:Ar = 1:0.8:1.3:1 and GHSV = 25,000 h(-1). The Cr-modified Ni/γ-Al2O3 catalyst was characterized by BET surface area analysis, X-ray diffraction (XRD), H2-temperature programmed reduction (TPR), H2-chmisorption, CO2-temperature programmed desorption (TPD) and Transmission electron microscopy(TEM). To confirm the amount and type of the carbon deposition, the used catalysts were examined by Thermogravitic analysis (TGA) and Field emission-scanning microscopy/Energy dispersive X-ray analysis (FE-SEM/EDX). It was found that the bimetallic Ni-Cr catalyst exhibits highly dispersed Ni particles with strong metal-to-support interaction (SMSI) as well as excellent catalytic activity, resulting in the suppression of Ni sintering and carbon deposition.

  8. A kinetic study of methanol synthesis in a slurry reactor using a CuO/ZnO/Al sub 2 O sub 3 catalyst

    SciTech Connect

    Al-Adwani, H.A.

    1992-05-01

    A kinetic model that describes the methanol production rate over a CuO/ZnO/AI{sub 2}0{sub 3} catalyst (United Catalyst L-951) at typical industrial operating conditions is developed using a slurry reactor. Different experiments are conducted in which the H{sub 2}/(CO+CO{sub 2}) ratio is equal to 2, 1, and 0.5, respectively, while the CO/CO{sub 2} ratio is held constant at 9. At each H{sub 2}/(CO+CO{sub 2}) ratio the space velocity is set at four different values in the range of 3000-13,000 1/hr kg{sub cat}. The effect of H{sub 2}/(CO+CO{sub 2}) ratio and space velocity on methanol production rate, conversions, and product composition is further investigated. The results indicate that the highest methanol production rate can be achieved at H{sub 2}/(CO+CO{sub 2}) ratio of 1 followed by H{sub 2}/(CO+CO{sub 2}) ratio of 0.5 and 2 respectively. The hydrogen and carbon monoxide conversions decrease with increasing space velocity for all H{sub 2}/(CO+CO{sub 2}) ratios tested. Carbon monoxide hydrogenation appears to be the main route to methanol at H{sub 2}/(CO+CO{sub 2}) ratio of 0.5 and 2. On the other hand, carbon dioxide hydrogenation appears to be the main route to methanol at H{sub 2}/(CO+CO{sub 2}) ratio of 1. At all H{sub 2}/(CO+CO{sub 2}) ratios, the extent of the reverse water gas shift reaction decreases with increasing space velocity. The effect of temperature on the kinetics is examined by using the same experimental approach at 508 K. It is found that a different reaction sequence takes place at each temperature. Also, a time on stream study is conducted simultaneously in order to investigate the characteristic of catalyst deactivation with time on stream. During the first 150 hours of time on stream, the catalyst loses approximately 2/3 of its initial activity before reaching a steady state activity.

  9. A kinetic study of methanol synthesis in a slurry reactor using a CuO/ZnO/Al{sub 2}O{sub 3} catalyst

    SciTech Connect

    Al-Adwani, H.A.

    1992-05-01

    A kinetic model that describes the methanol production rate over a CuO/ZnO/AI{sub 2}0{sub 3} catalyst (United Catalyst L-951) at typical industrial operating conditions is developed using a slurry reactor. Different experiments are conducted in which the H{sub 2}/(CO+CO{sub 2}) ratio is equal to 2, 1, and 0.5, respectively, while the CO/CO{sub 2} ratio is held constant at 9. At each H{sub 2}/(CO+CO{sub 2}) ratio the space velocity is set at four different values in the range of 3000-13,000 1/hr kg{sub cat}. The effect of H{sub 2}/(CO+CO{sub 2}) ratio and space velocity on methanol production rate, conversions, and product composition is further investigated. The results indicate that the highest methanol production rate can be achieved at H{sub 2}/(CO+CO{sub 2}) ratio of 1 followed by H{sub 2}/(CO+CO{sub 2}) ratio of 0.5 and 2 respectively. The hydrogen and carbon monoxide conversions decrease with increasing space velocity for all H{sub 2}/(CO+CO{sub 2}) ratios tested. Carbon monoxide hydrogenation appears to be the main route to methanol at H{sub 2}/(CO+CO{sub 2}) ratio of 0.5 and 2. On the other hand, carbon dioxide hydrogenation appears to be the main route to methanol at H{sub 2}/(CO+CO{sub 2}) ratio of 1. At all H{sub 2}/(CO+CO{sub 2}) ratios, the extent of the reverse water gas shift reaction decreases with increasing space velocity. The effect of temperature on the kinetics is examined by using the same experimental approach at 508 K. It is found that a different reaction sequence takes place at each temperature. Also, a time on stream study is conducted simultaneously in order to investigate the characteristic of catalyst deactivation with time on stream. During the first 150 hours of time on stream, the catalyst loses approximately 2/3 of its initial activity before reaching a steady state activity.

  10. Lapping slurry

    SciTech Connect

    Simandl, R.F.; Upchurch, V.S.; Leitten, M.E.

    1999-01-05

    Improved lapping slurries provide for easier and more thorough cleaning of alumina work pieces, as well as inhibit corrosion of the lapping table and provide for easier cleaning of the lapping equipment. The unthickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, and triethanolamine. The thickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, triethanolamine, a water soluble silicate, and acid. 1 fig.

  11. Lapping slurry

    DOEpatents

    Simandl, Ronald F.; Upchurch, Victor S.; Leitten, Michael E.

    1999-01-01

    Improved lapping slurries provide for easier and more thorough cleaning of alumina workpieces, as well as inhibit corrosion of the lapping table and provide for easier cleaning of the lapping equipment. The unthickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, and triethanolamine. The thickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, triethanolamine, a water soluble silicate, and acid.

  12. Development of alternative fuels from coal-derived syngas. Quarterly status report No. 6, January 1--March 31, 1992

    SciTech Connect

    Brown, D.M.

    1992-05-19

    The overall objectives of this program are to investigate potential technologies for the conversion of coal-derived synthesis gas to oxygenated fuels, hydrocarbon fuels, fuel intermediates, and octane enhancers; and to demonstrate the most promising technologies at DOE`s LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). BASF continues to have difficulties in scaling-up the new isobutanol synthesis catalyst developed in Air Products` laboratories. Investigations are proceeding, but the proposed operation at LaPorte in April is now postponed. DOE has accepted a proposal to demonstrate Liquid Phase Shift (LPS) chemistry at LaPorte as an alternative to isobutanol. There are two principal reasons for carrying out this run. First, following the extensive modifications at the site, operation on a relatively ``benign`` system is needed before we start on Fischer-Tropsch technology in July. Second, use of shift catalyst in a slurry reactor will enable DOE`s program on coal-based Fischer-Tropsch to encompass commercially available cobalt catalysts-up to now they have been limited to iron-based catalysts which have varying degrees of shift activity. In addition, DOE is supportive of continued fuel testing of LaPorte methanol-tests of MIOO at Detroit Diesel have been going particularly well. LPS offers the opportunity to produce methanol as the catalyst, in the absence of steam, is active for methanol synthesis.

  13. Development of alternative fuels from coal-derived syngas

    SciTech Connect

    Brown, D.M.

    1992-05-19

    The overall objectives of this program are to investigate potential technologies for the conversion of coal-derived synthesis gas to oxygenated fuels, hydrocarbon fuels, fuel intermediates, and octane enhancers; and to demonstrate the most promising technologies at DOE's LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). BASF continues to have difficulties in scaling-up the new isobutanol synthesis catalyst developed in Air Products' laboratories. Investigations are proceeding, but the proposed operation at LaPorte in April is now postponed. DOE has accepted a proposal to demonstrate Liquid Phase Shift (LPS) chemistry at LaPorte as an alternative to isobutanol. There are two principal reasons for carrying out this run. First, following the extensive modifications at the site, operation on a relatively benign'' system is needed before we start on Fischer-Tropsch technology in July. Second, use of shift catalyst in a slurry reactor will enable DOE's program on coal-based Fischer-Tropsch to encompass commercially available cobalt catalysts-up to now they have been limited to iron-based catalysts which have varying degrees of shift activity. In addition, DOE is supportive of continued fuel testing of LaPorte methanol-tests of MIOO at Detroit Diesel have been going particularly well. LPS offers the opportunity to produce methanol as the catalyst, in the absence of steam, is active for methanol synthesis.

  14. Potassium-Promoted Molybdenum Carbide as a Highly Active and Selective Catalyst for CO2 Conversion to CO.

    PubMed

    Porosoff, Marc D; Baldwin, Jeffrey W; Peng, Xi; Mpourmpakis, Giannis; Willauer, Heather D

    2017-06-09

    The high concentration of CO2 bound in seawater represents a significant opportunity to extract and use this CO2 as a C1 feedstock for synthetic fuels. Using an existing process, CO2 and H2 can be concurrently extracted from seawater and then catalytically reacted to produce synthetic fuel. Hydrogenating CO2 directly into liquid hydrocarbons is exceptionally difficult, but by first identifying a catalyst for selective CO production through the reverse water-gas shift (RWGS) reaction, CO can then be hydrogenated to fuel through Fischer-Tropsch (FT) synthesis. Results of this study demonstrate that potassium-promoted molybdenum carbide supported on γ-Al2 O3 (K-Mo2 C/γ-Al2 O3 ) is a low-cost, stable, and highly selective catalyst for RWGS over a wide range of conversions. These findings are supported by X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculations. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. A Self-Perpetuating Catalyst for the Production of Complex Organic Molecules in Protostellar Nebulae

    NASA Technical Reports Server (NTRS)

    Nuth, Joseph A.; Johnson, N. M.

    2010-01-01

    The formation of abundant carbonaceous material in meteorites is a long standing problem and an important factor in the debate on the potential for the origin of life in other stellar systems. Many mechanisms may contribute to the total organic content in protostellar nebulae, ranging from organics formed via ion-molecule and atom-molecule reactions in the cold dark clouds from which such nebulae collapse, to similar ion-molecule and atom-molecule reactions in the dark regions of the nebula far from the proto star, to gas phase reactions in sub-nebulae around growing giant planets and in the nebulae themselves. The Fischer-Tropsch-type (FTT) catalytic reduction of CO by hydrogen was once the preferred model for production of organic materials in the primitive solar nebula. The Haber-Bosch catalytic reduction of N2 by hydrogen was thought to produce the reduced nitrogen found in meteorites. However, the clean iron metal surfaces that catalyze these reactions are easily poisoned via reaction with any number of molecules, including the very same complex organics that they produce and both reactions work more efficiently in the hot regions of the nebula. We have demonstrated that many grain surfaces can catalyze both FTT and HB-type reactions, including amorphous iron and magnesium silicates, pure silica smokes as well as several minerals. Although none work as well as pure iron grains, and all produce a wide range of organic products rather than just pure methane, these materials are not truly catalysts.

  16. Magnetic and Mössbauer study of metal-zeolite interaction in catalysts

    NASA Astrophysics Data System (ADS)

    Pannaparayil, Thomas; Oskooie-Tabrizi, M.; Lo, C.; Mulay, L. N.; Melson, G. A.; Rao, V. U. S.

    1984-03-01

    Molecular sieve aluminosilicates, such as ZSM-5 and mordenite, when impregnated with highly dispersed Fe, yield catalysts for the selective conversion of coal-derived syngas (CO+H2) to liquid hydrocarbon fuels. Fe performs the primary Fischer-Tropsch (FT) syngas to yield light olefins which are converted by the acidic (H+) and shape-selective function of the zeolite to high octane gasoline components. The physical aspects of the Fe-mordenite interaction studied by magnetic measurements, Mössbauer, and IR spectroscopy are reported and correlations with the catalytic properties are drawn. Mordenite samples with [SiO2/Al2O3] ratio in the range 12 - 60 were impregnated with 15 wt. % Fe using Fe3(CO)12; decarbonylation yielded superparamagmetic dispersions of γ-Fe2O3, in the range 1.4-5.0 nm; the smallest particles were obtained for a ratio=17. Hydrogen chemisorption also revealed a similar trend in Fe dispersions. No samples, other than the one with a ratio=60 and containing the largest particles could be carbided under usual conditions. The acidity of the mordenite and the aromatics fraction in liquid hydrocarbons from syngas conversion also showed maxima at a ratio=17. The presence of a strong metal-support interaction between Fe and mordenite was thus influenced by the varying ratios in the mordenite in a manner that paralleled the acidity and catalytic activity.

  17. Suspended-slurry reactor

    SciTech Connect

    2016-03-22

    An apparatus for generating a large volume of gas from a liquid stream is disclosed. The apparatus includes a first channel through which the liquid stream passes. The apparatus also includes a layer of catalyst particles suspended in a solid slurry for generating gas from the liquid stream. The apparatus further includes a second channel through which a mixture of converted liquid and generated gas passes. A heat exchange channel heats the liquid stream. A wicking structure located in the second channel separates the gas generated from the converted liquid.

  18. Metallic cobalt nanoparticles imbedded into ordered mesoporous carbon: A non-precious metal catalyst with excellent hydrogenation performance.

    PubMed

    Liu, Jiangyong; Wang, Zihao; Yan, Xiaodong; Jian, Panming

    2017-11-01

    Ordered mesoporous carbon (OMC)-metal composites have attracted great attention owing to their combination of high surface area, controlled pore size distribution and physicochemical properties of metals. Herein, we report the cobalt nanoparticles/ordered mesoporous carbon (CoNPs@OMC) composite prepared by a one-step carbonization/reduction process assisted by a hydrothermal pre-reaction. The CoNPs@OMC composite presents a high specific surface area of 544m(2)g(-1), and the CoNPs are uniformly imbedded or confined in the ordered mesoporous carbon matrix. When used as a non-precious metal-containing catalyst for hydrogenation reduction of p-nitrophenol and nitrobenzene, it demonstrates high efficiency and good cycling stability. Furthermore, the CoNPs@OMC composite can be directly used to catalyze the Fischer-Tropsch synthesis for the high-pressure CO hydrogenation, and presents a good catalytic selectivity for C5(+) hydrocarbons. The excellent catalytic performance of the CoNPs@OMC composite can be ascribed to synergistic effect between the high specific surface area, mesoporous structure and well-imbedded CoNPs in the carbon matrix. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Novel Catalysts and Processing Technologies for Production of Aerospace Fuels from Non-Petroleum Raw Materials

    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.

  20. Continuous bench-scale slurry catalyst testing: Direct coal liquefaction of rawhide sub-bituminous coal. Final topical report, June 1994--December 1994

    SciTech Connect

    Coless, L.A.; Poole, M.C.; Wen, M.Y.

    1995-11-21

    Supported catalysts, either in fixed bed or ebullating bed reactors, are subject to deactivation with time, especially if the feed contains deactivating species, such as metals and coke precursors. Dispersed catalyst systems avoid significant catalyst deactivation because there are no catalyst pores to plug, hence no pore mouth plugging, and hopefully, no relevant decline of catalyst surface area or pore volume. The tests carried out in 1994, at the Exxon Research and Development Laboratories (ERDL) for DOE covered a slate of 5 dispersed catalysts for direct coal liquefaction of Rawhide sub-bituminous coal, which is similar to the Black Thunder coal tested earlier at Wilsonville. The catalysts included three iron and two molybdenum types. The Bailey iron oxide and the two molybdenum catalysts have previously been tested in DOE-sponsored research. These known catalysts will be used to help provide a base line and tie-in to previous work. The two new catalysts, Bayferrox PK 5210 and Mach-1`s Nanocat are very finely divided iron oxides. The iron oxide addition rate was varied from 1.0 to 0.25 wt % (dry coal basis) but the molybdenum addition rate remained constant at 100 wppm throughout the experiments. The effect of changing recycle rate, sulfur and iron oxide addition rates, first stage reactor temperature, mass velocity and catalyst type were tested in the 1994 operations of ERDL`s recycle coal liquefaction unit (RCLU). DOE will use these results to update economics and plan future work. The test program will resume in mid 1995, with another 2-3 months of pilot plant testing.

  1. Silver doped catalysts for treatment of exhaust

    DOEpatents

    Park, Paul Worn; Hester, Virgil Raymond; Ragle, Christie Susan; Boyer, Carrie L.

    2009-06-02

    A method of making an exhaust treatment element includes washcoating a substrate with a slurry that includes a catalyst support material. At least some of the catalyst support material from the slurry may be transferred to the substrate, and silver metal (Ag) is dispersed within the catalyst support material.

  2. Silver doped catalysts for treatment of exhaust

    DOEpatents

    Park, Paul Worn [Peoria, IL; Boyer, Carrie L [Shiloh, IL

    2006-12-26

    A method of making an exhaust treatment catalyst includes dispersing a metal-based material in a first solvent to form a first slurry and allowing polymerization of the first slurry to occur. Polymerization of the first slurry may be quenched and the first slurry may be allowed to harden into a solid. This solid may be redistributed in a second solvent to form a second slurry. The second slurry may be loaded with a silver-based material, and a silver-loaded powder may be formed from the second slurry.

  3. Filtering reprecipitated slurry

    SciTech Connect

    Morrissey, M.F.

    1992-01-01

    As part of the Late Washing Demonstration at Savannah River Technology Center, Interim Waste Technology has filtered reprecipitated and non reprecipitated slurry with the Experimental Laboratory Filter (ELF) at TNX. Reprecipitated slurry generates higher permeate fluxes than non reprecipitated slurry. Washing reprecipitated slurry may require a defoamer because reprecipitation encourages foaming.

  4. Filtering reprecipitated slurry

    SciTech Connect

    Morrissey, M.F.

    1992-12-31

    As part of the Late Washing Demonstration at Savannah River Technology Center, Interim Waste Technology has filtered reprecipitated and non reprecipitated slurry with the Experimental Laboratory Filter (ELF) at TNX. Reprecipitated slurry generates higher permeate fluxes than non reprecipitated slurry. Washing reprecipitated slurry may require a defoamer because reprecipitation encourages foaming.

  5. Synthesis and stabilization of supported metal catalysts by atomic layer deposition.

    PubMed

    Lu, Junling; Elam, Jeffrey W; Stair, Peter C

    2013-08-20

    Supported metal nanoparticles are among the most important catalysts for many practical reactions, including petroleum refining, automobile exhaust treatment, and Fischer-Tropsch synthesis. The catalytic performance strongly depends on the size, composition, and structure of the metal nanoparticles, as well as the underlying support. Scientists have used conventional synthesis methods including impregnation, ion exchange, and deposition-precipitation to control and tune these factors, to establish structure-performance relationships, and to develop better catalysts. Meanwhile, chemists have improved the stability of metal nanoparticles against sintering by the application of protective layers, such as polymers and oxides that encapsulate the metal particle. This often leads to decreased catalytic activity due to a lack of precise control over the thickness of the protective layer. A promising method of catalyst synthesis is atomic layer deposition (ALD). ALD is a variation on chemical vapor deposition in which metals, oxides, and other materials are deposited on surfaces by a sequence of self-limiting reactions. The self-limiting character of these reactions makes it possible to achieve uniform deposits on high-surface-area porous solids. Therefore, design and synthesis of advanced catalysts on the nanoscale becomes possible through precise control over the structure and composition of the underlying support, the catalytic active sites, and the protective layer. In this Account, we describe our advances in the synthesis and stabilization of supported metal catalysts by ALD. After a short introduction to the technique of ALD, we show several strategies for metal catalyst synthesis by ALD that take advantage of its self-limiting feature. Monometallic and bimetallic catalysts with precise control over the metal particle size, composition, and structure were achieved by combining ALD sequences, surface treatments, and deposition temperature control. Next, we describe

  6. Research on Si-Al based catalysts prepared by complete liquid-phase method for DME synthesis in a slurry reactor

    NASA Astrophysics Data System (ADS)

    Li, Zhihong; Zuo, Zhijun; Huang, Wei; Xie, Kechang

    2011-01-01

    A series of Si-Al based DME synthesis catalysts were prepared by complete liquid-phase method and characterized by in situ XPS, XRD, N 2 adsorption and NH 3-TPD analyses. Based on the results, the addition of Si could adjust the pore structure and surface acidity of catalyst, exhibiting a strong promoting effect on the CO conversion and DME selectivity. However, when Si/Al ratio is higher, Si would cover active sites and increase the amount of strong acidity sites, causing the reduction in catalytic activity. It was found from in situ XPS characterization that Cu 0 is the active center of methanol synthesis in DME production, and the addition of Si changes the chemical surroundings of active components and weaken the interaction between Cu, Zn and Al, which maybe give rise to the decrease in catalyst stability.

  7. Chemists report slurry breakthroughs for syngas-to-alcohol process

    SciTech Connect

    Rotman, D.

    1996-04-24

    Scientists at North Carolina State University (Raleigh) report that they have developed an alcohol synthesis process that uses a high-temperature slurry reactor with a conventional zinc chromite methanol catalyst. The scientists say it is the first time zinc-chromite catalysts have been used in slurry reactors at temperatures as high as 375 C. They add that it could lead to a synthesis gas (syngas)-based route to higher alcohols and to broader commercial applications for slurry reactors. Slurry reactors typically operate at less than 300 C, limiting applications for many high-volume industrial applications. By extending the temperature 100 C, says George Roberts, a chemist at North Carolina State, the work could {open_quotes}open up chemistry never run in slurry reactors before.{close_quotes} Roberts points to potential for use in partial oxidation reactions and synthesis routes involving formaldehyde.

  8. Relating FTS Catalyst Properties to Performance

    NASA Technical Reports Server (NTRS)

    Ma, Wenping; Ramana Rao Pendyala, Venkat; Gao, Pei; Jermwongratanachai, Thani; Jacobs, Gary; Davis, Burton H.

    2016-01-01

    During the reporting period June 23, 2011 to August 31, 2013, CAER researchers carried out research in two areas of fundamental importance to the topic of cobalt-based Fischer-Tropsch Synthesis (FTS): promoters and stability. The first area was research into possible substitute promoters that might be used to replace the expensive promoters (e.g., Pt, Re, and Ru) that are commonly used. To that end, three separate investigations were carried out. Due to the strong support interaction of ?-Al2O3 with cobalt, metal promoters are commonly added to commercial FTS catalysts to facilitate the reduction of cobalt oxides and thereby boost active surface cobalt metal sites. To date, the metal promoters examined have been those up to and including Group 11. Because two Group 11 promoters (i.e., Ag and Au) were identified to exhibit positive impacts on conversion, selectivity, or both, research was undertaken to explore metals in Groups 12 - 14. The three metals selected for this purpose were Cd, In, and Sn. At a higher loading of 25%Co on alumina, 1% addition of Cd, In, or Sn was found to-on average-facilitate reduction by promoting a heterogeneous distribution of cobalt consisting of larger lesser interacting cobalt clusters and smaller strongly interacting cobalt species. The lesser interacting species were identified in TPR profiles, where a sharp low temperature peak occurred for the reduction of larger, weakly interacting, CoO species. In XANES, the Cd, In, and Sn promoters were found to exist as oxides, whereas typical promoters (e.g., Re, Ru, Pt) were previously determined to exist in an metallic state in atomic coordination with cobalt. The larger cobalt clusters significantly decreased the active site density relative to the unpromoted 25%Co/Al2O3 catalyst. Decreasing the cobalt loading to 15%Co eliminated the large non-interacting species. The TPR peak for reduction of strongly interacting CoO in the Cd promoted catalyst occurred at a measurably lower temperature

  9. CO chemisorption and dissociation at high coverages during CO hydrogenation on Ru catalysts.

    PubMed

    Loveless, Brett T; Buda, Corneliu; Neurock, Matthew; Iglesia, Enrique

    2013-04-24

    Density functional theory (DFT) and infrared spectroscopy results are combined with mechanism-based rate equations to assess the structure and thermodynamics of chemisorbed CO (CO*) and its activation during Fischer-Tropsch synthesis (FTS). CO* binding becomes weaker with increasing coverage on Ru(0001) and Ru201 clusters, but such decreases in binding energy occur at higher coverages on Ru201 clusters than on Ru(0001) surfaces (CO*/Ru = 1.55 to 0.75); such differences appear to reflect weaker repulsive interactions on the curved surfaces prevalent on small Ru201 clusters. Ru201 clusters achieve stable supramonolayer coverages (CO*/Ru > 1) by forming geminal dicarbonyls at low-coordination corner/edge atoms. CO* infrared spectra on Ru/SiO2 (~7 nm diameter) detect mobile adlayers that anneal into denser structures at saturation. Mechanism-based FTS rate equations give activation energies that reflect the CO*-saturated surfaces prevalent during catalysis. DFT-derived barriers show that CO* predominantly reacts at (111) terraces via H-assisted reactions, consistent with measured effects of H2 and CO pressures and cluster size effects on rates and O-rejection selectivities. Barriers are much higher for unassisted CO* dissociation on (111) terraces and low-coordination atoms, including step-edge sites previously proposed as active sites for CO* dissociation during FTS. DFT-derived barriers indicate that unassisted CO* dissociation is irreversible, making such steps inconsistent with measured rates. The modest activation barriers of H-assisted CO* dissociation paths remove a requirement for special low-coordination sites for unassisted CO* activation, which is inconsistent with higher rates on larger clusters. These conclusions seem generally applicable to Co, Fe, and Ru catalysts, which show similar FTS rate equations and cluster size effects. This study also demonstrates the feasibility and relevance of DFT treatments on the curved and crowded cluster surfaces where

  10. Enhancement of Glycerol Steam Reforming Activity and Thermal Stability by Incorporating CeO2 and TiO2 in Ni- and Co-MCM-41 Catalysts

    NASA Astrophysics Data System (ADS)

    Dade, William N.

    Hydrogen (H2) has many applications in industry with current focus shifted to production of hydrocarbon fuels and valuable oxygenates using the Fischer-Tropsch technology and direct use in proton exchange membrane fuel cell (PEMFC). Hydrogen is generally produced via steam reforming of natural gas or alcohols like methanol and ethanol. Glycerol, a by-product of biodiesel production process, is currently considered to be one of the most attractive sources of sustainable H2 due to its high H/C ratio and bio-based origin. Ni and Co based catalysts have been reported to be active in glycerol steam reforming (GSR); however, deactivation of the catalysts by carbon deposition and sintering under GSR operating conditions is a major challenge. In this study, a series of catalysts containing Ni and Co nanoparticles incorporated in CeO2 and TiO2 modified high surface area MCM-41 have been synthesized using one-pot method. The catalysts are tested for GSR (at H2O/Glycerol mole ratio of 12 and GHSV of 2200 h-1) to study the effect of support modification and reaction temperature (450 - 700 °C) on the product selectivity and long term stability. GSR results revealed that all the catalysts performed significantly well exhibiting over 85% glycerol conversion at 650 °C except Ni catalysts that showed better low temperature activities. Deactivation studies of the catalysts conducted at 650 °C indicated that the Ni-TiO2-MCM-41 and Ni-CeO 2-MCM-41 were resistant to deactivation with ˜100% glycerol conversion for 40 h. In contrast, Co-TiO2-MCM-41 perform poorly as the catalyst rapidly deactivated after 12 h to yield ˜20% glycerol conversion after 40 h. The WAXRD and TGA-DSC analyses of spent catalysts showed a significant amount of coke deposition that might explain catalysts deactivation. The flattening shape of the original BET type IV isotherm with drastic reduction of catalyst surface area can also be responsible for observed drop in catalysts activities.

  11. Sizing pumps for slurries

    SciTech Connect

    Akhtar, S.Z.

    1996-11-01

    Slurry characteristics have a significant impact on centrifugal pump performance. For instance, as particle size increases or the percent solids concentration increases, pump head and efficiency decrease. Therefore, before a slurry pump is selected, it is important to define the slurry characteristics as accurately as possible. The effect of the slurry characteristics on the head and efficiency of the centrifugal pump will be emphasized (the effect on flowrate is less significant). The effect of slurry characteristics is more predominant in smaller pumps (with smaller diameter impellers) than in larger pumps. The data and relationship between the various slurry parameters have been developed from correlations and nomographs published by pump vendors from their field data and test results. The information helps to avoid specifying an undersized pump/motor assembly for slurry service.

  12. CATALYSIS SCIENCE INITIATIVE: From First Principles Design to Realization of Bimetallic Catalysts for Enhanced Selectivity

    SciTech Connect

    MAVRIKAKIS, MANOS DUMESIC, JAMES A.

    2007-05-03

    In this project, we have integrated state-of-the-art Density Functional Theory (DFT) models of heterogeneous catalytic processes with high-throughput screening of bimetallic catalytic candidates for important industrial problems. We have studied a new class of alloys characterized by a surface composition different from the bulk composition, and investigated their stability and activity for the water-gas shift reaction and the oxygen reduction reaction. The former reaction is an essential part of hydrogen production; the latter is the rate-limiting step in low temperature H2 fuel cells. We have identified alloys that have remarkable stability and activity, while having a much lower material cost for both of these reactions. Using this knowledge of bimetallic interactions, we have also made progress in the industrially relevant areas of carbohydrate reforming and conversion of biomass to liquid alkanes. One aspect of this work is the conversion of glycerol (a byproduct of biodiesel production) to synthesis gas. We have developed a bifunctional supported Pt catalyst that can cleave the carbon-carbon bond while also performing the water-gas shift reaction, which allows us to better control the H2:CO ratio. Knowledge gained from the theoretical metal-metal interactions was used to develop bimetallic catalysts that perform this reaction at low temperature, allowing for an efficient coupling of this endothermic reaction with other reactions, such as Fischer-Tropsch or methanol synthesis. In our work on liquid alkane production from biomass, we have studied deactivation and selectivity in these areas as a function of metal-support interactions and reaction conditions, with an emphasis on the bifunctionality of the catalysts studied. We have identified a stable, active catalyst for this process, where the selectivity and yield can be controlled by the reaction conditions. While complete rational design of catalysts is still elusive, this work demonstrates the power of

  13. Aqueous-phase reforming of n-BuOH over Ni/Al 2O 3 and Ni/CeO 2 catalysts

    NASA Astrophysics Data System (ADS)

    Roy, B.; Sullivan, H.; Leclerc, C. A.

    The aqueous-phase reforming (APR) of n-butanol (n-BuOH) over Ni(20 wt%) loaded Al 2O 3 and CeO 2 catalysts has been studied in this paper. Over 100 h of run time, the Ni/Al 2O 3 catalyst showed significant deactivation compared to the Ni/CeO 2 catalyst, both in terms of production rates and the selectivity to H 2 and CO 2. The Ni/CeO 2 catalyst demonstrated higher selectivity for H 2 and CO 2, lower selectivity to alkanes, and a lower amount of C in the liquid phase compared to the Ni/Al 2O 3 sample. For the Ni/Al 2O 3 catalyst, the selectivity to CO increased with temperature, while the Ni/CeO 2 catalyst produced no CO. For the Ni/CeO 2 catalyst, the activation energies for H 2 and CO 2 production were 146 and 169 kJ mol -1, while for the Ni/Al 2O 3 catalyst these activation energies were 158 and 175 kJ mol -1, respectively. The difference of the active metal dispersion on Al 2O 3 and CeO 2 supports, as measured from H 2-pulse chemisorption was not significant. This indicates deposition of carbon on the catalyst as a likely cause of lower activity of the Ni/Al 2O 3 catalyst. It is unlikely that carbon would build up on the Ni/CeO 2 catalyst due to higher oxygen mobility in the Ni doped non-stoichiometric CeO 2 lattice. Based on the products formed, the proposed primary reaction pathway is the dehydrogenation of n-BuOH to butaldehyde followed by decarbonylation to propane. The propane then partially breaks down to hydrogen and carbon monoxide through steam reforming, while CO converts to CO 2 mostly through water gas shift. Ethane and methane are formed via Fischer-Tropsch reactions of CO/CO 2 with H 2.

  14. ULTRA-CLEAN FISCHER-TROPSCH FUELS PRODUCTION AND DEMONSTRATION PROJECT

    SciTech Connect

    Steve Bergin

    2004-10-18

    The Report Abstract provides summaries of the past year's activities relating to each of the main project objectives. Some of the objectives will be expanded on in greater detail further down in the report. The following objectives have their own addition sections in the report: SFP Construction and Fuel Production, Impact of SFP Fuel on Engine Performance, Fleet Testing at WMATA and Denali National Park, Demonstration of Clean Diesel Fuels in Diesel Electric Generators in Alaska, and Economic Analysis. ICRC provided overall project organization and budget management for the project. ICRC held meetings with various project participants. ICRC presented at the Department of Energy's annual project review meeting. The plant began producing fuel in October 2004. The first delivery of finished fuel was made in March of 2004 after the initial start-up period.

  15. Properties of Fischer-Tropsch (FT) Blends for Use in Military Equipment

    DTIC Science & Technology

    2006-04-01

    of advanced rockets , scramjets and combined cycle propulsion systems. The near-term use of FT fuels in existing military fleets is not without...production of FT fuels . Fortunately, the capture of CO2 can be accommodated by today’s coal gasification processes. Furthermore, CO2 storage has been...Corporation Leo L. Stavinoha Stavinoha Enterprises ABSTRACT Clean, very low sulfur fuels produced from domestic resources are of interest to the U.S

  16. Ace in the Hole: Fischer-Tropsch Fuels and National Security

    DTIC Science & Technology

    2010-05-24

    German might.”9 As the Allies’ strategic bombing campaign destroyed German refineries and choked imports from Rumanian refineries , Germany relied more...hydrocarbon structure.53 The 16 synthetic fuel contains no impurities, providing a superior aviation fuel with no sulfur emissions or particulates, and... emissions , Congress effectively killed CTL fuel development in the United States with an amendment to the Energy Independence and Security Act so that

  17. A Perspective of Joint Agency Collaboration on Fischer-Tropsch Fuels (2003-2005)

    DTIC Science & Technology

    2008-08-13

    separate measurements Mostly methyl -substitued isoparaffins, progressively less substitution by ethyl + longer chain groups (S-5, Syntroleum Corp.) Zero...blends of FT kerosene and JP-8 Vision DoD/AT&L intends to catalyze commercial industry to produce clean fuels for the military from secure domestic resources using environmentally sensitive processes as a bridge to the future.

  18. Fischer-Tropsch diesel emulsions stabilised by microfibrillated cellulose and nonionic surfactants.

    PubMed

    Lif, Anna; Stenstad, Per; Syverud, Kristin; Nydén, Magnus; Holmberg, Krister

    2010-12-15

    Water-in-diesel emulsion fuels have been prepared with a combination of sorbitan monolaurate and glycerol monooleate as emulsifier and with microfibrillated cellulose (MFC) of different hydrophilic/hydrophobic character as stabilizer. The MFC was treated with either octadecylamine or poly(styrene-co-maleic anhydride), resulting in very hydrophobic fibrils. The most stable emulsion was achieved with a combination of hydrophilic (untreated) and hydrophobic MFC and only minute amounts of the stabilizer gave a pronounced effect. Even with the optimized formulation the lifetime of the emulsion was shorter than previously reported when a conventional polymeric stabilizer was used, however. The water drop sizes in the emulsions were determined by three methods: optical images, light scattering, and NMR diffusometry. All three methods gave water drops sizes of ca 2 μm. The NMR diffusometry indicated that besides the micrometer-sized emulsion drops a significant fraction of the water is present in small droplets of micelle size. The chemical exchange of water between these two populations of pools is believed to be the reason for the relatively low stability of the system.

  19. Stability and effects of carbon-induced surface reconstructions in cobalt Fischer-Tropsch synthesis

    NASA Astrophysics Data System (ADS)

    Ciobîcă, I. M.; van Helden, P.; van Santen, R. A.

    2016-11-01

    This computational study of carbon induced reconstruction of Co surfaces demonstrates that surface reconstruction is stable in the presence of a hydrogen at low coverage. These reconstructions can create new sites that allow for low activation energy CO dissociation. Carbon induced surface reconstruction of the edge of the FCC-Co(221) step surface will result in highly reactive step-edge sites. Such sites also provide a low activation energy for carbon to diffuse into the subsurface layer of cobalt.

  20. The benefits of Fischer-Tropsch waxes in synthetic petroleum jelly.

    PubMed

    Bekker, M; Louw, N R; Jansen Van Rensburg, V J; Potgieter, J

    2013-02-01

    This article is an introduction and general discussion regarding the use of Fisher-Tropsch wax in petroleum jelly applications. Traditionally, petroleum jelly is prepared from a blend of microwax, paraffin wax and mineral oil that are all derived from crude oil. Sasol Wax has successfully prepared a petroleum jelly based on predominantly to fully synthetic Fisher-Tropsch wax. Sasol Wax was awarded a patent P53898ZP00-29 November 11 for a predominantly to fully synthetic petroleum jelly based on Fisher-Tropsch wax blends. The benefits of Fisher-Tropsch wax discussed in this article include the absence of aromatic compounds and polycyclic aromatic compounds in Fisher-Tropsch wax as well as the sustainable production that is possible with Fisher-Tropsch wax, as opposed to paraffin wax that may be affected by the closure of group I Base Oil plants. This article will be the first in a series of articles from the same authors, and follow-up articles will include solid-state nuclear magnetic resonance and crystallization studies to determine the influence of predominantly synthetic waxes on petroleum jelly network structures compared with more traditional mineral oil-derived petroleum jellies, final product performance and stability of synthetic petroleum jelly used in, for example, personal care lotions or creams. The influence of oxygenated compounds and product safety and rheological properties (including primary skin feel upon application and secondary skin feel after application) of synthetic petroleum jellies compared with traditional mineral oil-derived petroleum jellies are discussed. © 2012 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  1. Effect of structural promoters on Fe-based Fischer-Tropsch synthesis of biomass derived syngas

    Treesearch

    Pratibha Sharma; Thomas Elder; Leslie H. Groom; James J. Spivey

    2014-01-01

    Biomass gasification and subsequent conversion of this syngas to liquid hydrocarbons using Fischer–Tropsch (F–T) synthesis is a promising source of hydrocarbon fuels. However, biomass-derived syngas is different from syngas obtained from other sources such as steam reforming of methane. Specifically the H2/CO ratio is less than 1/1 and the CO

  2. Synthetic Fischer-Tropsch (FT) JP-5/JP-8 Aviation Turbine Fuel Elastomer Compatibility

    DTIC Science & Technology

    2005-02-01

    of nitrile coupons and O-rings with selected petroleum-derived fuels, Fisher-Tropsch (FT) synthetic JP-5/JP-8 fuel, and blends of FT JP-5/JP-8 with...SUPPLEMENTARY NOTES The original document contains color images. 14. ABSTRACT When some elastomer ( rubber ) compounds, and specifically those used for...various amounts of aromatic blend stock. This study provided a baseline for predicting the effects of static elastomer swell to the potential degree of

  3. Ultra-Clean Fischer-Tropsch Fuels Production and Demonstration Project

    SciTech Connect

    Steve Bergin

    2005-10-14

    The Report Abstract provides summaries of the past year's activities relating to each of the main project objectives. Some of the objectives will be expanded on in greater detail further down in the report. The following objectives have their own addition sections in the report: Dynamometer Durability Testing, the Denali Bus Fleet Demonstration, Bus Fleet Demonstrations Emissions Analysis, Impact of SFP Fuel on Engine Performance, Emissions Analysis, Feasibility Study of SFPs for Rural Alaska, and Cold Weather Testing of Ultra Clean Fuel.

  4. Ultrasound Analysis of Slurries

    DOEpatents

    Soong, Yee and Blackwell, Arthur G.

    2005-11-01

    An autoclave reactor allows for the ultrasonic analysis of slurry concentration and particle size distribution at elevated temperatures and pressures while maintaining the temperature- and pressure-sensitive ultrasonic transducers under ambient conditions. The reactor vessel is a hollow stainless steel cylinder containing the slurry which includes a stirrer and a N, gas source for directing gas bubbles through the slurry. Input and output transducers are connected to opposed lateral portions of the hollow cylinder for respectively directing sound waves through the slurry and receiving these sound waves after transmission through the slurry, where changes in sound wave velocity and amplitude can be used to measure slurry parameters. Ultrasonic adapters connect the transducers to the reactor vessel in a sealed manner and isolate the transducers from the hostile conditions within the vessel without ultrasonic signal distortion or losses.

  5. Ultrasound Analysis Of Slurries

    DOEpatents

    Soong, Yee; Blackwell, Arthur G.

    2005-11-01

    An autoclave reactor allows for the ultrasonic analysis of slurry concentration and particle size distribution at elevated temperatures and pressures while maintaining the temperature- and pressure-sensitive ultrasonic transducers under ambient conditions. The reactor vessel is a hollow stainless steel cylinder containing the slurry which includes a stirrer and a N.sub.2 gas source for directing gas bubbles through the slurry. Input and output transducers are connected to opposed lateral portions of the hollow cylinder for respectively directing sound waves through the slurry and receiving these sound waves after transmission through the slurry, where changes in sound wave velocity and amplitude can be used to measure slurry parameters. Ultrasonic adapters connect the transducers to the reactor vessel in a sealed manner and isolate the transducers from the hostile conditions within the vessel without ultrasonic signal distortion or losses.

  6. Combustion of Agglomerates Formed by Carbon Slurry Fuels.

    DTIC Science & Technology

    1983-11-01

    catalyst are small, suggesting that fuel development efforts should concentrate on properties which Improve atomization ; (2) combustor performance...concluded that major fuel formulation efforts should concentrate on improving the atomization quality of carbon-black slurries--as opposed to efforts to...concentrated on improving the atomization quality of carbon-black slurries as opposed to efforts to increase the fundamental reactivity of the

  7. The BTL2 process of biomass utilization entrained-flow gasification of pyrolyzed biomass slurries.

    PubMed

    Raffelt, Klaus; Henrich, Edmund; Koegel, Andrea; Stahl, Ralph; Steinhardt, Joachim; Weirich, Friedhelm

    2006-01-01

    Forschungszentrum Karlsruhe has developed a concept for the utilization of cereal straw and other thin-walled biomass with high ash content. The concept consists of a regional step (drying, chopping, flash-pyrolysis, and mixing) and a central one (pressurized entrained-flow gasification, gas cleaning, synthesis of fuel, and production of byproducts). The purpose of the regional plant is to prepare the biomass by minimizing its volume and producing a stable and safe storage and transport form. In the central gasifier, the pyrolysis products are converted into syngas. The syngas is tar-free and can be used for Fischer-Tropsch synthesis after gas cleaning.

  8. Engineering Development of Slurry Bubble Column Reactor (SBCR) Technology

    SciTech Connect

    Puneet Gupta

    2002-07-31

    This report summarizes the procedures used and results obtained in determining radial gas holdup profiles, via gamma ray scanning, and in assessing liquid and gas mixing parameters, via radioactive liquid and gas tracers, during Fischer Tropsch synthesis. The objectives of the study were (i) to develop a procedure for detection of gas holdup radial profiles in operating reactors and (ii) to test the ability of the developed, previously described, engineering models to predict the observed liquid and gas mixing patterns. It was shown that the current scanning procedures were not precise enough to obtain an accurate estimate of the gas radial holdup profile and an improved protocol for future use was developed. The previously developed physically based model for liquid mixing was adapted to account for liquid withdrawal from the mid section of the column. The ability of our engineering mixing models for liquid and gas phase to predict both liquid and gas phase tracer response was established and illustrated.

  9. Circulation in gas-slurry column reactors

    SciTech Connect

    Clark, N.; Kuhlman, J.; Celik, I.; Gross, R.; Nebiolo, E.; Wang, Yi-Zun.

    1990-08-15

    Circulation in bubble columns, such as those used in fischer-tropsch synthesis, detracts from their performance in that gas is carried on average more rapidly through the column, and the residence time distribution of the gas in the column is widened. Both of these factors influence mass-transfer operations in bubble columns. Circulation prediction and measurement has been undertaken using probes, one-dimensional models, laser Doppler velocimetry, and numerical modeling. Local void fraction was measured using resistance probes and a newly developed approach to determining air/water threshold voltage for the probe. A tall column of eight inch diameter was constructed of Plexiglas and the distributor plate was manufactured to distribute air evenly through the base of the column. Data were gathered throughout the volume at three different gas throughputs. Bubble velocities proved difficult to measure using twin probes with cross-correlation because of radial bubble movement. A series of three-dimensional mean and RMS bubble and liquid velocity measurements were also obtained for a turbulent flow in a laboratory model of a bubble column. These measurements have been made using a three-component laser Doppler velocimeter (LDV), to determine velocity distributions non-intrusively. Finally, the gas-liquid flow inside a vertically situated circular isothermal column reactor was simulated numerically. 74 refs., 170 figs., 5 tabs.

  10. Mn2O3 Slurry Achieving Reduction of Slurry Waste

    NASA Astrophysics Data System (ADS)

    Kishii, Sadahiro; Nakamura, Ko; Hanawa, Kenzo; Watanabe, Satoru; Arimoto, Yoshihiro; Kurokawa, Syuhei; Doi, Toshiro K.

    2012-04-01

    Fumed silica is widely used for SiO2 chemical mechanical polishing (CMP). In semiconductor processes, only fresh slurry is used, the used slurry being disposed of. We have demonstrated that Mn2O3 abrasive slurry polishes dielectric SiO2 film, giving 4 times the removal rate of conventional fumed silica slurry. The higher removal rate reduces the total amount of slurry used, consequently reducing the amount of used slurry waste. The removal rate of Mn2O3 slurry remains constant for solid concentrations between l and 10 wt %, and stays constant without pad conditioning. These characteristics are very useful for slurry reuse. Remanufacture of Mn2O3 slurry from used slurry has been demonstrated, and the removal rates of the remanufactured and fresh slurries are the same. Reuse and remanufacturing drastically reduce the amount of waste.

  11. ICE SLURRY APPLICATIONS

    PubMed Central

    Kauffeld, M.; WANG, M. J.; Goldstein, V.; Kasza, K. E.

    2011-01-01

    The role of secondary refrigerants is expected to grow as the focus on the reduction of greenhouse gas emissions increases. The effectiveness of secondary refrigerants can be improved when phase changing media are introduced in place of single phase media. Operating at temperatures below the freezing point of water, ice slurry facilitates several efficiency improvements such as reductions in pumping energy consumption as well as lowering the required temperature difference in heat exchangers due to the beneficial thermo-physical properties of ice slurry. Research has shown that ice slurry can be engineered to have ideal ice particle characteristics so that it can be easily stored in tanks without agglomeration and then be extractable for pumping at very high ice fraction without plugging. In addition ice slurry can be used in many direct contact food and medical protective cooling applications. This paper provides an overview of the latest developments in ice slurry technology. PMID:21528014

  12. Structure and function of real catalysts

    NASA Astrophysics Data System (ADS)

    Klier, K.

    1984-11-01

    such as carbon monoxide or unsaturated hydrocarbons through back-bonding of the copper d-orbitals into the π ∗ orbitals of the substrates. In a paper by D.L. Roberts and G.L. Griffin at this Symposium, additional evidence is presented that the same finely dispersed Cu species are the chemisorption and activation sites for hydrogen. Some significant mechanistic features of carbon monoxide hydrogenation are demonstrated by the enhancement of methanol synthesis rates and carbon-carbon bond formation in the presence of alkali promoters. The nature and concentration of the alkali ions on the catalyst surface determine the outcome of the carbon monoxide hydrogenations in the following way: (i) of all the alkali and alkaline earth promoters, cesium displays the most pronounced effects; (ii) at high temperatures and low hydrogen-to-carbon monoxide ratios, maximum amount of n-propanol and 2-methyl-propanol is observed in the product over the Cs/Cu/ZnO catalysts, consistent with the function of the alkali as base catalysts in aldol condensation of aldehydic or enolic surface intermediates; (iii) at low temperatures and high hydrogen-to-carbon monoxide ratios, cesium enhances methanol synthesis as well as water gas shift rates in water- and CO 2-free synthesis gas, retards the methanol synthesis rate in synthesis gas containing intermediate amounts of water, primarily due to loss of surface area upon cesium doping, and again accelerates the synthesis in water-rich synthesis gas. These latter effects point to a mechanism in which the rate of formation of surface formate is enhanced by cesium in water-free synthesis gas and a rapid removal of surface hydroxyls free sites that activate hydrogen in water-rich synthesis gas. The role of Group VIII metals as promoters of the Cu/ZnO catalysts for low alcohol and hydrocarbon synthesis is represented by the effects of small additions of iron. Product composition is intermediate between that in methanol and Fischer-Tropsch syntheses

  13. Pressurized Vessel Slurry Pumping

    SciTech Connect

    Pound, C.R.

    2001-09-17

    This report summarizes testing of an alternate ''pressurized vessel slurry pumping'' apparatus. The principle is similar to rural domestic water systems and ''acid eggs'' used in chemical laboratories in that material is extruded by displacement with compressed air.

  14. Iron-oxide aerogel and xerogel catalyst formulations: characterization by 57Fe Mössbauer and XAFS spectroscopies.

    PubMed

    Huggins, Frank E; Bali, Sumit; Huffman, Gerald P; Eyring, Edward M

    2010-06-01

    Iron in various iron-oxide aerogel and xerogel catalyst formulations (> or =85% Fe(2)O(3); < or =10% K, Co, Cu, or Pd) developed for possible use in Fischer-Tropsch synthesis (FTS) or the water-gas-shift (WGS) reaction has been examined by (57)Fe Mössbauer spectroscopy. The seventeen samples consisted of both as-prepared and calcined aerogels and xerogels and their products after use as catalysts for FTS or the WGS reaction. Complementary XAFS spectra were obtained on the occurrence of the secondary elements in some of the same materials. A broad, slightly asymmetric, two-peak Mössbauer spectrum was obtained from the different as-prepared and calcined catalyst formulations in the majority of cases. Such spectra could only be satisfactorily fit with three quadrupole doublet components, but no systematic trends in the isomer shift and quadrupole splitting parameters and area ratios of the individual components could be discerned that reflected variations in the composition or preparation of the aerogel or xerogel materials. However, significant reductions were noted in the Mössbauer effective thickness (recoilless absorption effect per unit mass of iron) parameter, chi(eff)/g, determined at room temperature, for aerogels and xerogels compared to bulk iron oxides, reflecting the openness and lack of rigidity of the aerogel and xerogel structures. Mössbauer measurements for two aerogels over the range from 15 to 292K confirmed the greatly diminished nature of this parameter at room temperature. Major increases in the effective thickness parameter were observed when the open structure of the aerogel or xerogel collapsed during calcination resulting in the formation of iron oxides (hematite, spinel ferrite). Similar structural changes were indicated by increases in this parameter after use of iron-oxide aerogels as catalysts for FTS or the WGS reaction, during which the iron-oxide aerogel was converted to a mixture of nonstoichiometric magnetite and the Hägg carbide

  15. Iron-oxide Aerogel and Xerogel Catalyst Formulations: Characterization by 57Fe Mössbauer and XAFS Spectroscopies

    SciTech Connect

    Huggins, F.; Bali, S; Huffman, G; Eyring, E

    2010-01-01

    Iron in various iron-oxide aerogel and xerogel catalyst formulations ({ge}85% Fe{sub 2}O{sub 3}; {le}10% K, Co, Cu, or Pd) developed for possible use in Fischer-Tropsch synthesis (FTS) or the water-gas-shift (WGS) reaction has been examined by {sup 57}Fe Moessbauer spectroscopy. The seventeen samples consisted of both as-prepared and calcined aerogels and xerogels and their products after use as catalysts for FTS or the WGS reaction. Complementary XAFS spectra were obtained on the occurrence of the secondary elements in some of the same materials. A broad, slightly asymmetric, two-peak Moessbauer spectrum was obtained from the different as-prepared and calcined catalyst formulations in the majority of cases. Such spectra could only be satisfactorily fit with three quadrupole doublet components, but no systematic trends in the isomer shift and quadrupole splitting parameters and area ratios of the individual components could be discerned that reflected variations in the composition or preparation of the aerogel or xerogel materials. However, significant reductions were noted in the Moessbauer effective thickness (recoilless absorption effect per unit mass of iron) parameter, {chi}{sub eff}/g, determined at room temperature, for aerogels and xerogels compared to bulk iron oxides, reflecting the openness and lack of rigidity of the aerogel and xerogel structures. Moessbauer measurements for two aerogels over the range from 15 to 292 K confirmed the greatly diminished nature of this parameter at room temperature. Major increases in the effective thickness parameter were observed when the open structure of the aerogel or xerogel collapsed during calcination resulting in the formation of iron oxides (hematite, spinel ferrite). Similar structural changes were indicated by increases in this parameter after use of iron-oxide aerogels as catalysts for FTS or the WGS reaction, during which the iron-oxide aerogel was converted to a mixture of nonstoichiometric magnetite and

  16. Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

    DOEpatents

    Doherty, J.P.; Marek, J.C.

    1987-02-25

    A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper(II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the original organic compounds, is subsequently blended with high level radioactive sludge land transferred to a vitrification facility for processing into borosilicate glass for long-term storage. 2 figs., 3 tabs.

  17. Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

    DOEpatents

    Doherty, Joseph P.; Marek, James C.

    1989-01-01

    A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper (II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the orginal organic compounds, is subsequently blended with high level radioactive sludge and transferred to a virtrification facility for processing into borosilicate glass for long-term storage.

  18. Small Molecule Catalysts for Harvesting Methane Gas

    SciTech Connect

    Baker, S. E.; Ceron-Hernandez, M.; Oakdale, J.; Lau, E. Y.

    2016-12-06

    As the average temperature of the earth increases the impact of these changes are becoming apparent. One of the most dramatic changes to the environment is the melting of arctic permafrost. The disappearance of the permafrost has resulted in release of streams of methane that was trapped in remote areas as gas hydrates in ice. Additionally, the use of fracking has also increased emission of methane. Currently, the methane is either lost to the atmosphere or flared. If these streams of methane could be brought to market, this would be an abundant source of revenue. A cheap conversion of gaseous methane to a more convenient form for transport would be necessary to economical. Conversion of methane is a difficult reaction since the C-H bond is very stable (104 kcal/mole). At the industrial scale, the Fischer-Tropsch reaction can be used to convert gaseous methane to liquid methanol but is this method is impractical for these streams that have low pressures and are located in remote areas. Additionally, the Fischer-Tropsch reaction results in over oxidation of the methane leading to many products that would need to be separated.

  19. Study of the Feasibility of a Coal-to-Liquids Plant in Interior Alaska

    DTIC Science & Technology

    2011-05-12

    Syngas Treatment – Fischer-Tropsch (F-T) Synthesis & Upgrading ...Separation Unit Coal Preparation Gasifier Syngas Treatment F-T and Upgrading Power Generation oxygen dried coal or slurried coal raw syngas syngas air...Water Balance Example clean syngas from Gas Purification 261 psi steam to Power Generation prelleated BFW blowdO\\’ffl to Water

  20. Activation of catalysts for synthesizing methanol from synthesis gas

    DOEpatents

    Blum, David B.; Gelbein, Abraham P.

    1985-01-01

    A method for activating a methanol synthesis catalyst is disclosed. In this method, the catalyst is slurried in an inert liquid and is activated by a reducing gas stream. The activation step occurs in-situ. That is, it is conducted in the same reactor as is the subsequent step of synthesizing methanol from a methanol gas stream catalyzed by the activated catalyst still dispersed in a slurry.

  1. Slurry bubble column hydrodynamics

    NASA Astrophysics Data System (ADS)

    Rados, Novica

    Slurry bubble column reactors are presently used for a wide range of reactions in both chemical and biochemical industry. The successful design and scale up of slurry bubble column reactors require a complete understanding of multiphase fluid dynamics, i.e. phase mixing, heat and mass transport characteristics. The primary objective of this thesis is to improve presently limited understanding of the gas-liquid-solid slurry bubble column hydrodynamics. The effect of superficial gas velocity (8 to 45 cm/s), pressure (0.1 to 1.0 MPa) and solids loading (20 and 35 wt.%) on the time-averaged solids velocity and turbulent parameter profiles has been studied using Computer Automated Radioactive Particle Tracking (CARPT). To accomplish this, CARPT technique has been significantly improved for the measurements in highly attenuating systems, such as high pressure, high solids loading stainless steel slurry bubble column. At a similar set of operational conditions time-averaged gas and solids holdup profiles have been evaluated using the developed Computed Tomography (CT)/Overall gas holdup procedure. This procedure is based on the combination of the CT scans and the overall gas holdup measurements. The procedure assumes constant solids loading in the radial direction and axially invariant cross-sectionally averaged gas holdup. The obtained experimental holdup, velocity and turbulent parameters data are correlated and compared with the existing low superficial gas velocities and atmospheric pressure CARPT/CT gas-liquid and gas-liquid-solid slurry data. The obtained solids axial velocity radial profiles are compared with the predictions of the one dimensional (1-D) liquid/slurry recirculation phenomenological model. The obtained solids loading axial profiles are compared with the predictions of the Sedimentation and Dispersion Model (SDM). The overall gas holdup values, gas holdup radial profiles, solids loading axial profiles, solids axial velocity radial profiles and solids

  2. New slurry pumps in China

    SciTech Connect

    Li, Z.; Wang, W.; Shi, Z.

    1998-07-01

    Wet parts of centrifugal slurry pumps are naturally subjected to wear, but local wear in pumps could be avoided, at least partly. Through studying the wear phenomenon of slurry pumps in industrial applications, a series of much more advanced slurry pumps was developed in China. Laboratory tests and industrial applications show that the new pumps are high in efficiency when transporting slurries, and uniform wear can be expected from them.

  3. New slurry pumps in China

    SciTech Connect

    Zhengwang Li; Wenlie Wang; Zhongyin Shi

    1998-04-01

    Wet parts of centrifugal slurry pumps are naturally subjected to wear, but local wear in pumps could be avoided, at least partly. Through studying the wear phenomenon of slurry pumps in industrial applications, a series of much more advanced slurry pumps was developed in China. Laboratory tests and industrial applications show that the new pumps are high in efficiency when transporting slurries, and uniform wear can be expected from them.

  4. Dimethyl ether synthesis from syngas in slurry phase

    SciTech Connect

    Han, Y.Z.; Fujimoto, K.; Shikata, T.

    1997-12-31

    Dimethyl ether (DME) is one of the important chemicals derived from synthesis gas. It can be widely used in syngas conversion, production of olefins, or MTG gasoline. Recently, is has been noticed as a substitute of LPG used as home fuel. In the present study, dimethyl ether was effectively synthesized from CO rich syngas (H{sub 2}/CO=1/1) over hybrid catalyst containing a Cu-Zn-Al(O) based methanol synthesis catalyst and {gamma}-alumina in an agitated slurry reactor under relatively mild reaction conditions: temperature 230--300 C, pressure 2.0--5.0 MPa, contact time 2.0--10 gram-cat.-h/mol. The catalysts used as the methanol active components were commercially available Cu-Zn-Al(O) based catalysts, BASF S385 and ICI 51-2. Two kinds of {gamma}-alumina ALO4 (standard catalyst of the Catalysis Society of Japan) and N612N (NIKKI Co., Japan) were used as the methanol dehydration components. The slurry was prepared by mixing the fine powder (<100 mesh) of catalyst components with purified n-hexadecane. The catalysts were reduced by a mixing gas containing 20% syngas and 80% nitrogen with a three-hour programmed temperature raising from room temperature to the final temperature. All products were analyzed by gas chromatographs. Results are given and discussed.

  5. Slurry transport medium

    SciTech Connect

    Rosenthal, W.; Schiffman, L.

    1980-06-03

    This invention provides for an improvement in slurry transport systems, especially coal slurry lines. Instead of the usual use of fresh water resources which, in some geographic areas, are scarce for slurry transport, concentrated brine is used which is prepared from abundant salt water resources. Because of the higher density of this concentrated brine, it is a superior carrier of pulverized material. It diminishes the separation and settling tendency of slurry components during transport and particularly during shutdown. Other advantages in the use of concentrated brine include: freezing point depression which permits ease of transport during winter and at lower temperatures; dust suppression of stored coal; avoidance of spontaneous combustion of stored coal; inhibit freeze packing of dewatered pipeline coal; and diminished extent of corrosion in ferrous metal pipelines as compared to that which might occur with lower concentration brines. Important in the economy of the process is that the concentrated brine can be recycled. An inexpensive method for producing the concentrated brine is given.

  6. Carbon Slurry Secondary Atomization.

    DTIC Science & Technology

    1986-09-01

    ELEMENT NO. NO. N ACCESSION NO. 1 62203F 3048 I 05 I 34 11 TITLE (Include Securty Clasification ) Carbon Slurry Secondary Atomization 12. PERSONAL AUTHOR(S...density, size, and induction time. Any continuing program in this area should attempt to keep these criteria in mind . IV. VOLATILE ADDITIVE STUDIES 1

  7. System and method for slurry handling

    DOEpatents

    Steele, Raymond Douglas; Oppenheim, Judith Pauline

    2015-12-29

    A system includes a slurry depressurizing system that includes a liquid expansion system configured to continuously receive a slurry at a first pressure and continuously discharge the slurry at a second pressure. For example, the slurry depressurizing system may include an expansion turbine to expand the slurry from the first pressure to the second pressure.

  8. Design, Synthesis, and Mechanistic Evaluation of Iron-Based Catalysis for Synthesis Gas Conversion to Fuels and Chemicals

    SciTech Connect

    Enrique Iglesia

    2004-09-30

    This project explores the extension of previously discovered Fe-based catalysts with unprecedented Fischer-Tropsch synthesis rate, selectivity, and ability to convert hydrogen-poor synthesis gas streams typical of those produced from coal and biomass sources. Contract negotiations were completed on December 9, 2004. During the first reporting period, we certified a microreactor, installed required analytical equipment, and reproduced synthetic protocols and catalytic performance previously reported. During this second reporting period, we have prepared and tested several Fe-based compositions for Fischer-Tropsch synthesis and tested the effects of product recycle under both subcritical and supercritical conditions. These studies established modest improvements in rates and selectivities with light hydrocarbon recycle without any observed deleterious effects, opening up the opportunities for using of recycle strategies to control temperature profiles in fixed-bed Fe-based Fischer-Tropsch synthesis reactors without any detectable kinetic detriment. In a parallel study, we examined similar effects of recycle for cobalt-based catalysts; marked selectivity improvements were observed as a result of the removal of significant transport restrictions on these catalysts. Finally, we have re-examined some previously unanalyzed data dealing with the mechanism of the Fischer-Tropsch synthesis, specifically kinetic isotope effects on the rate and selectivity of chain growth reactions on Fe-based catalysts.

  9. Current Issues in Molecular Catalysis Illustrated by Iron Porphyrins as Catalysts of the CO2-to-CO Electrochemical Conversion.

    PubMed

    Costentin, Cyrille; Robert, Marc; Savéant, Jean-Michel

    2015-12-15

    Recent attention aroused by the reduction of carbon dioxide has as main objective the production of useful products, the "solar fuels", in which solar energy would be stored. One route to this goal is the design of photochemical schemes that would operate this conversion using directly sun light energy. An indirect approach consists in first converting sunlight energy into electricity then using it to reduce CO2 electrochemically. Conversion of carbon dioxide into carbon monoxide is thus a key step through the classical dihydrogen-reductive Fischer-Tropsch chemistry. Direct and catalytic electrochemical CO2 reduction already aroused active interest during the 1980-1990 period. The new wave of interest for these matters that has been growing since 2012 is in direct conjunction with modern energy issues. Among molecular catalysts, electrogenerated Fe(0) porphyrins have proved to be particularly efficient and robust. Recent progress in this field has closely associated the search of more and more efficient catalysts in the iron porphyrin family with an unprecedentedly rigorous deciphering of mechanisms. Accordingly, the coupling of proton transfer with electron transfer and breaking of one of the two C-O bonds of CO2 have been the subjects of relentless scrutiny and mechanistic analysis with systematic investigation of the degree of concertedness of these three events. Catalysis of the electrochemical CO2-to-CO conversion has thus been a good testing ground for the mechanism diagnostic strategies and the all concerted reactivity model proposed then. The role of added Brönsted acids, both as H-bond providers and proton donors, has been elucidated. These efforts have been a preliminary to the inclusion of the acid functionalities within the catalyst molecule, giving rise to considerable increase of the catalytic efficiency. The design of more and more efficient catalysts made it necessary to propose "catalytic Tafel plots" relating the turnover frequency to the

  10. Indirect conversion of coal to fuel and chemicals by the Sasol slurry phase distillate process

    SciTech Connect

    Jager, B.

    1997-12-31

    Sasol was established in 1950 to convert low grade coal reserves into petroleum products and petrochemical feed stock. The first plant was commissioned in 1955 and two further plants followed in 1980 and 1982. Today Sasol produces the equivalent of 150,000 bbl/day of fuels and chemical feedstock from more than 40 million tons of low grade coal. In converting coal to petroleum products, coal is first gasified with oxygen and steam to syngas, a mixture of H{sub 2} and CO, which after purification is converted to hydrocarbons and some oxygenates by means of the Fischer-Tropsch process (FT). In the Sasol plants Lurgi Fixed Bed Dry Bottom gasifiers are used and the FT is performed in either the Low Temperature or High Temperature FT process. Over the years an ongoing program of optimization has led to numerous modifications and improvements. These improvements resulted in increased operational stability of the process, reduced mechanical wear and extended life of components. This paper describes the technology and the modifications which have improved the process, including the integration of the process with reforming of natural gas. Fischer-Tropsch in combination with gasification of coal has been used successfully and profitably for over 40 years for the production of synfuels and petrochemical products. In new plants syncrude obtained from FT in combination with reforming of natural gas can compete with crude oil for the production of fuels and chemicals where cheap natural gas is available (such as stranded gas in remote areas). This has become possible due to the development of much more efficient FT reactors and the proper integration of reforming and the FT process.

  11. INEZ, KENTUCKY COAL SLURRY SPILL

    EPA Science Inventory

    On October 11th, 2000, a breach of a coal slurry impoundment released approximately 210 million gallons of coal slurry ( a mixture of fine coal particles, silt, clay, sand and water) into the Big Andy Branch, Wolf Creek, and Coldwater Fork. Approximately 75 river miles were affec...

  12. DEHYDRATION OF DEUTERIUM OXIDE SLURRIES

    DOEpatents

    Hiskey, C.F.

    1959-03-10

    A method is presented for recovering heavy water from uranium oxide-- heavy water slurries. The method consists in saturating such slurries with a potassium nitrate-sodium nitrate salt mixture and then allowing the self-heat of the slurry to raise its temperature to a point slightly in excess of 100 deg C, thus effecting complete evaporation of the free heavy water from the slurry. The temperature of the slurry is then allowed to reach 300 to 900 deg C causing fusion of the salt mixture and expulsion of the water of hydration. The uranium may be recovered from the fused salt mixture by treatment with water to leach the soluble salts away from the uranium-containing residue.

  13. Rheometry of natural sediment slurries

    USGS Publications Warehouse

    Major, Jon J.; ,

    1993-01-01

    Recent experimental analyses of natural sediment slurries yield diverse results yet exhibit broad commonality of rheological responses under a range of conditions and shear rates. Results show that the relation between shear stress and shear rate is primarily nonlinear, that the relation can display marked hysteresis, that minimum shear stress can occur following yield, that physical properties of slurries are extremely sensitive to sediment concentration, and the concept of slurry yield strength is still debated. New rheometric analyses have probed viscoelastic behavior of sediment slurries. Results show that slurries composed of particles ??? 125 ?? m exhibit viscoelastic responses, and that shear stresses are relaxed over a range of time scales rather than by a single response time.

  14. Fischer-tropsch synthesis in supercritical fluids. Quarterly technical progress report, April 1, 1993--June 30, 1993

    SciTech Connect

    Akgerman, A.; Bukur, D.B.

    1993-07-29

    We have completed modifications of the Taylor Dispersion Apparatus so that propane can be used as a solvent. Problems were encountered initially compressing propane to the necessary pressures because of cavitation in the liquid pump. This problem was overcome by placing a check valve in the line after the pump and pressures of 2500 psi have been achieved. The system has been pressure tested by using a soap solution on exposed joints and performing a mass balance (leak test). The mass balance was made by reading the volumetric flow rate of liquid in the syringe pump and converting this to expected gas flow rate. The liquid was then vaporized and a dry gas meter measured the amount of gas at the exit of the apparatus. The expected and measured gas flow rates were in excellent agreement, indicating that there are no significant leaks in the system. Presently, we are having problems with the use of UV detection for the dim using compounds. The detector is successfully auto-zeroing with a blank cell and with Co{sub 2}. With the use of instrument grade propane, however, the detector is unable to auto-zero because of absorption of unknown impurity. We believe this problem is caused by a sulfur compound in the propane gas cylinder and we plan to install an active carbon guard bed to remove a sulfur containing compounds.

  15. Fischer-Tropsch synthesis in supercritical fluids. Quarterly technical progress report, April 1, 1996--June 30, 1996

    SciTech Connect

    Akgerman, A.; Bukur, D.B.

    1996-12-31

    For the task on diffusion coefficients of F-T products in supercritical fluids, we attempted to find a model for the {beta} parameter to predict the molecular diffusion coefficients to a high degree of accuracy so we may be able to predict both the molecular diffusion coefficient and thus the effective diffusivity a priori. The dependency of solvent/solute interactions on the {beta} parameter was analyzed and a correlation developed to predict the functionality. This allowed us to develop an empirical formula to correlate the molecular diffusion coefficient to ratios of mass, size, and density. Thus finally allowing for supercritical fluid diffusion predictions a priori. Figure 6 shows our predictions of the data available on the self diffusion coefficient of carbon dioxide (Chen, 1983; Takahashi and Iwasaki, 1966) ethylene (Arends et al., 1981; Baker et al., 1984), toluene (Baker et al., 1985) and chlorotrifuoromethane (Harris, 1978). The predictions, with no parameters adjusted from the data, are excellent with an average absolute error of 3.64%.

  16. Economic analysis of distributed processing of biomass to bio-oil for subsequent production of Fischer-Tropsch liquids

    USDA-ARS?s Scientific Manuscript database

    Biorefineries are likely to be built with output capacities that are 25 times smaller than fossil fuel refineries due to the high cost of transporting biomass. There are various scenarios that can be employed to reduce biomass transportation costs and allow for lower fuel production costs at higher ...

  17. 40 CFR 721.10178 - Distillates (Fischer-Tropsch), hydroisomerized middle, C10-13-branched alkane fraction.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...), hydroisomerized middle, C10-13-branched alkane fraction. 721.10178 Section 721.10178 Protection of Environment...), hydroisomerized middle, C10-13-branched alkane fraction. (a) Chemical substance and significant new uses subject... middle, C10-13-branched alkane fraction (PMN P-04-319; CAS No. 642928-30-1) is subject to reporting...

  18. Indirect liquefaction of coal. [Coal gasification plus Fischer-Tropsch, methanol or Mobil M-gasoline process

    SciTech Connect

    1980-06-30

    The most important potential environmental problems uniquely associated with indirect liquefaction appear to be related to the protection of occupational personnel from the toxic and carcinogenic properties of process and waste stream constituents, the potential public health risks from process products, by-products and emissions and the management of potentially hazardous solid wastes. The seriousness of these potential problems is related partially to the severity of potential effects (i.e., human mortality and morbidity), but even more to the uncertainty regarding: (1) the probable chemical characteristics and quantities of process and waste streams; and (2) the effectiveness and efficiencies of control technologies not yet tested on a commercial scale. Based upon current information, it is highly improbable that these potential problems will actually be manifested or pose serious constraints to the development of indirect liquefaction technologies, although their potential severity warrants continued research and evaluation. The siting of indirect liquefaction facilities may be significantly affected by existing federal, state and local regulatory requirements. The possibility of future changes in environmental regulations also represents an area of uncertainty that may develop into constraints for the deployment of indirect liquefaction processes. Out of 20 environmental issues identified as likely candidates for future regulatory action, 13 were reported to have the potential to impact significantly the commercialization of coal synfuel technologies. These issues are listed.

  19. Hydrodynamic models for slurry bubble column reactors

    SciTech Connect

    Gidaspow, D.

    1995-12-31

    The objective of this investigation is to convert a {open_quotes}learning gas-solid-liquid{close_quotes} fluidization model into a predictive design model. This model is capable of predicting local gas, liquid and solids hold-ups and the basic flow regimes: the uniform bubbling, the industrially practical churn-turbulent (bubble coalescence) and the slugging regimes. Current reactor models incorrectly assume that the gas and the particle hold-ups (volume fractions) are uniform in the reactor. They must be given in terms of empirical correlations determined under conditions that radically differ from reactor operation. In the proposed hydrodynamic approach these hold-ups are computed from separate phase momentum balances. Furthermore, the kinetic theory approach computes the high slurry viscosities from collisions of the catalyst particles. Thus particle rheology is not an input into the model.

  20. Enhanced conversion of syngas to liquid motor fuels

    DOEpatents

    Coughlin, Peter K.; Rabo, Jule A.

    1986-01-01

    Synthesis gas comprising carbon monoxide and hydrogen is converted to C.sub.5.sup.+ hydrocarbons suitable for use as liquid motor fuels by contact with a dual catalyst system capable of enhancing the selectivity of said conversion to motor fuel range hydrocarbons and the quality of the resulting motor fuel product. The catalyst composition employs a Fischer-Tropsch catalyst, together with a co-catalyst/support component comprising SAPO silicoaluminophosphate, non-zeolitic molecular sieve catalyst.

  1. Coal slurry pipelining

    SciTech Connect

    Chassagne, P.J.

    1980-02-05

    A method is disclosed for preparing industrial ores, e.g., coal, for pipelining and pipelining the ores to a site for subsequent processing or use. Ore from a mine is screened into two fractions, one having a large size particle distribution and one having a small size particle distribution, each fraction retaining both the ore and the refuse. The large size particle fraction is cleaned of refuse and the clean ore therefrom crushed to a size distribution of the smaller size or small size ore fraction. The separated refuse from the large size particle fraction is ground to provide superfines to the extent required for the proper particle size distribution for pipelining. The ore and superfine refuse are combined in a water slurry for pipelining. After pipelining the ore, the ore is cleaned and dewatered conveniently as known in the art for fine ore. The resulting ore may then be stockpiled or directly used.

  2. Manifold Coal-Slurry Transport System

    NASA Technical Reports Server (NTRS)

    Liddle, S. G.; Estus, J. M.; Lavin, M. L.

    1986-01-01

    Feeding several slurry pipes into main pipeline reduces congestion in coal mines. System based on manifold concept: feeder pipelines from each working entry joined to main pipeline that carries coal slurry out of panel and onto surface. Manifold concept makes coal-slurry haulage much simpler than existing slurry systems.

  3. NACA Research on Slurry Fuels

    NASA Technical Reports Server (NTRS)

    Pinns, M L; Olson, W T; Barnett, H C; Breitwieser, R

    1958-01-01

    An extensive program was conducted to investigate the use of concentrated slurries of boron and magnesium in liquid hydrocarbon as fuels for afterburners and ramjet engines. Analytical calculations indicated that magnesium fuel would give greater thrust and that boron fuel would give greater range than are obtainable from jet hydrocarbon fuel alone. It was hoped that the use of these solid elements in slurry form would permit the improvement to be obtained without requiring unconventional fuel systems or combustors. Small ramjet vehicles fueled with magnesium slurry were flown successfully, but the test flights indicated that further improvement of combustors and fuel systems was needed.

  4. Tribological Properties Of Coal Slurries

    NASA Technical Reports Server (NTRS)

    Fusaro, Robert L.; Schrubens, Dale L.

    1988-01-01

    Report describes study of tribological properties of coal/methanol slurries with pin-on-disk tribometer. Coefficients of friction, rates of wear of steel pin, and morphological studies of worn surfaces conducted on pins and disks of AISI 440C HT stainless steel and M-50 tool steel, both used as bearing steels. Coal slurries considered as replacement fuels in terrestrial oil-burning facilities and possible fuels for future aircraft turbine engines. Rates of wear of metallic components through which slurries flow limit such practical applications.

  5. Hydrocarbon synthesis catalyst and method of preparation

    DOEpatents

    Sapienza, R.S.; Sansone, M.J.; Slegeir, W.A.R.

    1983-08-02

    A catalyst for the synthesis of hydrocarbons from carbon monoxide and hydrogen composed of palladium or platinum and cobalt supported on a solid phase is disclosed. The catalyst is prepared by heating a heterogeneous component of the palladium or platinum deposited on the solid support in a solution of cobalt carbonyl or precursors thereof. The catalyst exhibits excellent activity, stability in air, and produces highly desirable product fractions even with dilute gaseous reactants. The catalyst is preferably used in dilute slurry form, which is desirable from a heat transfer standpoint. 9 figs.

  6. Hydrocarbon synthesis catalyst and method of preparation

    DOEpatents

    Sapienza, Richard S.; Sansone, Michael J.; Slegeir, William A. R.

    1983-08-02

    A catalyst for the synthesis of hydrocarbons from carbon monoxide and hydrogen composed of palladium or platinum and cobalt supported on a solid phase is disclosed. The catalyst is prepared by heating a heterogeneous component of the palladium or platinum deposited on the solid support in a solution of cobalt carbonyl or precursors thereof. The catalyst exhibits excellent activity, stability in air, and produces highly desirable product fractions even with dilute gaseous reactants. The catalyst is preferably used in dilute slurry form, which is desirable from a heat transfer standpoint.

  7. Streamline coal slurry letdown valve

    DOEpatents

    Platt, R.J.; Shadbolt, E.A.

    1983-11-08

    A streamlined coal slurry letdown valve is featured which has a two-piece throat comprised of a seat and seat retainer. The two-piece design allows for easy assembly and disassembly of the valve. A novel cage holds the two-piece throat together during the high pressure letdown. The coal slurry letdown valve has long operating life as a result of its streamlined and erosion-resistance surfaces. 5 figs.

  8. Streamline coal slurry letdown valve

    DOEpatents

    Platt, Robert J.; Shadbolt, Edward A.

    1983-01-01

    A streamlined coal slurry letdown valve is featured which has a two-piece throat comprised of a seat and seat retainer. The two-piece design allows for easy assembly and disassembly of the valve. A novel cage holds the two-piece throat together during the high pressure letdown. The coal slurry letdown valve has long operating life as a result of its streamlined and erosion-resistance surfaces.

  9. Ultrasonic characterization of slurries in an autoclave reactor at elevated temperature

    SciTech Connect

    Soong, Y.; Gamwo, I.K.; Blackwell, A.G.; Harke, F.W.; Schehl, R.R.; Zarochak, M.F.

    1996-06-01

    The application of the three-phase slurry reactor system for coal liquefaction processing and chemical industries has recently received considerable attention. To design and efficiently operate a three-phase slurry reactor, the degree of dispersion of the solid (catalyst) in the reactor must be understood and controlled. An ultrasonic technique was developed to measure the concentration of solids in an autoclave reactor. Preliminary measurements were conducted on slurries consisting of molten paraffin wax, glass beads, and nitrogen bubbles at 189 C. The data show that the velocity and attenuation of the sound are well-defined functions of the solid and gas concentrations in the molten wax. The results suggest possibilities for directly measuring solids concentration during operation of a three-phase slurry reactor.

  10. Medical ice slurry production device

    DOEpatents

    Kasza, Kenneth E [Palos Park, IL; Oras, John [Des Plaines, IL; Son, HyunJin [Naperville, IL

    2008-06-24

    The present invention relates to an apparatus for producing sterile ice slurries for medical cooling applications. The apparatus is capable of producing highly loaded slurries suitable for delivery to targeted internal organs of a patient, such as the brain, heart, lungs, stomach, kidneys, pancreas, and others, through medical size diameter tubing. The ice slurry production apparatus includes a slurry production reservoir adapted to contain a volume of a saline solution. A flexible membrane crystallization surface is provided within the slurry production reservoir. The crystallization surface is chilled to a temperature below a freezing point of the saline solution within the reservoir such that ice particles form on the crystallization surface. A deflector in the form of a reciprocating member is provided for periodically distorting the crystallization surface and dislodging the ice particles which form on the crystallization surface. Using reservoir mixing the slurry is conditioned for easy pumping directly out of the production reservoir via medical tubing or delivery through other means such as squeeze bottles, squeeze bags, hypodermic syringes, manual hand delivery, and the like.

  11. Comparative testing of slurry monitors

    SciTech Connect

    Hylton, T.D.; Bayne, C.K.; Anderson, M.S.; Van Essen, D.C.

    1998-05-01

    The US Department of Energy (DOE) has millions of gallons of radioactive liquid and sludge wastes that must be retrieved from underground storage tanks, transferred to treatment facilities, and processed to a final waste form. The wastes will be removed from the current storage tanks by mobilizing the sludge wastes and mixing them with the liquid wastes to create slurries. Each slurry would then be transferred by pipeline to the desired destination. To reduce the risk of plugging a pipeline, the transport properties (e.g., density, suspended solids concentration, viscosity, particle size range) of the slurry should be determined to be within acceptable limits prior to transfer. These properties should also be monitored and controlled within specified limits while the slurry transfer is in progress. The DOE issued a call for proposals for developing on-line instrumentation to measure the transport properties of slurries. In response to the call for proposals, several researchers submitted proposals and were funded to develop slurry monitoring instruments. These newly developed DOE instruments are currently in the prototype stage. Before the instruments were installed in a radioactive application, the DOE wanted to evaluate them under nonradioactive conditions to determine if they were accurate, reliable, and dependable. The goal of this project was to test the performance of the newly developed DOE instruments along with several commercially available instruments. The baseline method for comparison utilized the results from grab-sample analyses.

  12. Coal slurry fuel supply and purge system

    DOEpatents

    McDowell, Robert E.; Basic, Steven L.; Smith, Russel M.

    1994-01-01

    A coal slurry fuel supply and purge system for a locomotive engines is disclosed which includes a slurry recirculation path, a stand-by path for circulating slurry during idle or states of the engine when slurry fuel in not required by the engine, and an engine header fluid path connected to the stand-by path, for supplying and purging slurry fuel to and from fuel injectors. A controller controls the actuation of valves to facilitate supply and purge of slurry to and from the fuel injectors. A method for supplying and purging coal slurry in a compression ignition engine is disclosed which includes controlling fluid flow devices and valves in a plurality of fluid paths to facilitate continuous slurry recirculation and supply and purge of or slurry based on the operating state of the engine.

  13. Development of biodiesel slurry fuels

    SciTech Connect

    Suppes, G.J.; Ng, C.; Srinivasan, B.

    1994-12-31

    As an alternative to diesel, the DOE has recently supported research which developed coal-water-slurries to the extent that they have demonstrated in low-, medium-, and high-speed diesel engines. Coal-water-slurry (CWS) fuels would be an American-made alternative to diesel distilled from imported crude oil. Such alternatives to imported oil are particularly desirable as 1994 crude oil imports will most likely exceed those disastrously high levels of the early 1980`s which led to a major recession. This paper is on the testing and development of biodiesel slurry fuels (e.g. corn flour and water) as an alternative to diesel for use in a modified diesel engine. While the economics for CWS`s are not favorable until bulk, tax-free diesel prices exceed $0.80 per gallon, a preliminary analysis of biodiesel slurries shows economic viability at today`s diesel prices. This paper presents advantages of biodiesel slurries over CWS`s due to different ash compositions and economics specific to applications on farm tractors. Engine modifications, fuel costs, fuel processing, fuel performance, and on-going research are discussed.

  14. Alcohol synthesis in a high-temperature slurry reactor

    SciTech Connect

    Roberts, G.W.; Marquez, M.A.; McCutchen, M.S.

    1995-12-31

    The overall objective of this contract is to develop improved process and catalyst technology for producing higher alcohols from synthesis gas or its derivatives. Recent research has been focused on developing a slurry reactor that can operate at temperatures up to about 400{degrees}C and on evaluating the so-called {open_quotes}high pressure{close_quotes} methanol synthesis catalyst using this reactor. A laboratory stirred autoclave reactor has been developed that is capable of operating at temperatures up to 400{degrees}C and pressures of at least 170 atm. The overhead system on the reactor is designed so that the temperature of the gas leaving the system can be closely controlled. An external liquid-level detector is installed on the gas/liquid separator and a pump is used to return condensed slurry liquid from the separator to the reactor. In order to ensure that gas/liquid mass transfer does not influence the observed reaction rate, it was necessary to feed the synthesis gas below the level of the agitator. The performance of a commercial {open_quotes}high pressure {close_quotes} methanol synthesis catalyst, the so-called {open_quotes}zinc chromite{close_quotes} catalyst, has been characterized over a range of temperature from 275 to 400{degrees}C, a range of pressure from 70 to 170 atm., a range of H{sub 2}/CO ratios from 0.5 to 2.0 and a range of space velocities from 2500 to 10,000 sL/kg.(catalyst),hr. Towards the lower end of the temperature range, methanol was the only significant product.

  15. Coal-oil slurry preparation

    DOEpatents

    Tao, John C.

    1983-01-01

    A pumpable slurry of pulverized coal in a coal-derived hydrocarbon oil carrier which slurry is useful as a low-ash, low-sulfur clean fuel, is produced from a high sulfur-containing coal. The initial pulverized coal is separated by gravity differentiation into (1) a high density refuse fraction containing the major portion of non-coal mineral products and sulfur, (2) a lowest density fraction of low sulfur content and (3) a middlings fraction of intermediate sulfur and ash content. The refuse fraction (1) is gasified by partial combustion producing a crude gas product from which a hydrogen stream is separated for use in hydrogenative liquefaction of the middlings fraction (3). The lowest density fraction (2) is mixed with the liquefied coal product to provide the desired fuel slurry. Preferably there is also separately recovered from the coal liquefaction LPG and pipeline gas.

  16. Loose abrasive slurries for optical glass lapping

    SciTech Connect

    Neauport, Jerome; Destribats, Julie; Maunier, Cedric; Ambard, Chrystel; Cormont, Philippe; Pintault, B.; Rondeau, Olivier

    2010-10-20

    Loose abrasive lapping is widely used to prepare optical glass before its final polishing. We carried out a comparison of 20 different slurries from four different vendors. Slurry particle sizes and morphologies were measured. Fused silica samples were lapped with these different slurries on a single side polishing machine and characterized in terms of surface roughness and depth of subsurface damage (SSD). Effects of load, rotation speed, and slurry concentration during lapping on roughness, material removal rate, and SSD were investigated.

  17. Turbulence in slurry pipe flow

    SciTech Connect

    Gore, R.A. ); Crowe, C.T. . Dept. of Mechanical and Materials Engineering)

    1990-01-01

    The present state of knowledge of liquid-solid flows (slurries) is far behind than that for single phase flows. Very few geometries have been examined with a slurry and only with a limited variation of system parameters i.e. fluid viscosity, particle diameter, etc. This paper presents the first part of a study which examines the effects of the addition of a solid to the flow through a confined coaxial jet. Presented here will be the initial conditions for the jet which correspond to fully developed pipe flow. 6 refs., 9 figs.

  18. Oxidation catalyst

    DOEpatents

    Ceyer, Sylvia T.; Lahr, David L.

    2010-11-09

    The present invention generally relates to catalyst systems and methods for oxidation of carbon monoxide. The invention involves catalyst compositions which may be advantageously altered by, for example, modification of the catalyst surface to enhance catalyst performance. Catalyst systems of the present invention may be capable of performing the oxidation of carbon monoxide at relatively lower temperatures (e.g., 200 K and below) and at relatively higher reaction rates than known catalysts. Additionally, catalyst systems disclosed herein may be substantially lower in cost than current commercial catalysts. Such catalyst systems may be useful in, for example, catalytic converters, fuel cells, sensors, and the like.

  19. Supersonic coal water slurry fuel atomizer

    DOEpatents

    Becker, Frederick E.; Smolensky, Leo A.; Balsavich, John

    1991-01-01

    A supersonic coal water slurry atomizer utilizing supersonic gas velocities to atomize coal water slurry is provided wherein atomization occurs externally of the atomizer. The atomizer has a central tube defining a coal water slurry passageway surrounded by an annular sleeve defining an annular passageway for gas. A converging/diverging section is provided for accelerating gas in the annular passageway to supersonic velocities.

  20. DEMONSTRATION BULLETIN: SLURRY BIODEGRADATION, International Technology Corporation

    EPA Science Inventory

    This technology uses a slurry-phase bioreactor in which the soil is mixed with water to form a slurry. Microorganisms and nutrients are added to the slurry to enhance the biodegradation process, which converts organic wastes into relatively harmless byproducts of microbial metabo...