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Sample records for fischer-tropsch catalysts quarterly

  1. Catalysts for Fischer-Tropsch

    SciTech Connect

    Srivastava, R.D. ); Rao, V.U.S.; Cinquegrane, G.; Stiegel, G.J. )

    1990-02-01

    The slurry-phase Fischer-Tropsch (F-T) process has attracted considerable attention recently. The process can make liquid fuels by reacting hydrogen-lean synthesis gas produced from modern energy-efficient gasifiers. continuing assessment of Fischer-Tropsch Synthesis (FTS) has a high priority within an indirect liquefaction program, a part of the liquid fuels program sponsored by the U.S. Department of Energy (DOE) and executed by the Pittsburgh Energy Technology Center (PETC). Funding for the indirect liquefaction program in 1990:0090 is anticipated to be about $8.5 million compared to $6.6 million in 1989 and a like amount in the year before. The studies within the program are conducted by industry, universities, national laboratories and in-house PETC research and development. This article reviews preparation and properties of iron-based catalysts, including recent patent activities and in-depth process analysis of slurry-phase FTS. The review provides an analysis of Fischer-Tropsch catalyst research and development trends and describes options to increase selectivity for iron-based catalysts in a slurry phase.

  2. 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.

  3. 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.

  4. 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.

  5. Technology development for iron Fischer-Tropsch catalysts. Quarterly report, April--June 1993

    SciTech Connect

    Davis, B.H.

    1993-11-01

    The Fischer-Tropsch process has attracted a great deal of attention in terms of catalytic activity and selectivity to produce higher number hydrocarbons by reacting carbon monoxide and hydrogen at high pressures in the presence of catalysts. Shortly after the initial discovery, Fischer and Tropsch developed more active catalysts for indirect liquefaction. The product distribution resulting from the Fischer-Tropsch synthesis (FTS) varies widely depending upon the catalysts, the temperature and pressure of reactions, pretreatment conditions, etc. It is desirable to improve the selectivity while maintaining the activity intact. One approach to achieve this task is the addition of promoters such as oxides of K, Mn, Ti, Mo, Ni, and Co, etc. It was observed that most of these promoted catalysts exhibit an increase in selectivity to higher hydrocarbons. For example, the addition of thoria as a promoter to cobalt-kieselguhr catalysts resulted in an enhanced yield of C{sub 5}{sup +} hydrocarbons. Even a small amount of thoria promoter ({approximately}0.4 wt %) addition to Co/ZSM-5 causes a remarkable increase in the conversion, shift activity, and C{sub 5}{sup +} selectivity. Thoria added as a promoter to a precipitated iron oxide catalyst appears to decrease wax selectivity. It is generally believed that the factors such as dispersion effects of rare earth oxides and thoria, the redox properties, and the basic properties of rare earth oxides and thorium oxides, greatly influence the activity and selectivity.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. Catalyst and reactor development for a liquid-phase Fischer-Tropsch process. Quarterly technical progress report, 1 April 1981-30 June 1981

    SciTech Connect

    Brockington, J.W.; Dyer, P.N.; Pierantozzi, R.; Brain, B.W.; Bauer, J.V.

    1981-07-01

    In October 1980, Air Products and Chemicals, Inc. began a three year contract with the DOE: Catalyst and Reactor Development for a Liquid Phase Fischer-Tropsch Process. The program contains four major tasks: (1) Project Work Plan, (2) Slurry Catalyst Development, (3) Slurry Reactor Design Studies, and (4) Pilot Facility Design. This report describes work on Tasks 2 and 3 carried out in the third quarter of the contract. In Task 2, the computerized search of the Fischer-Tropsch literature was continued, and improvements were made in data processing programs. Shakedown tests were completed on the first 300 ml slurry reactor, and construction of the second and third reactors began. Five modified conventional slurry catalysts were prepared, and two batches were tested in the gas phase giving information on selectivity as a function of composition and activation. Four supported cluster catalyst were synthesized, and seven were tested in the gas phase.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Catalyst structure and method of Fischer-Tropsch synthesis

    DOEpatents

    Wang, Yong; Vanderwiel, David P.; Tonkovich, Anna Lee Y.; Gao, Yufei; Baker, Eddie G.

    2004-06-15

    The present invention includes Fischer-Tropsch catalysts, reactions using Fischer-Tropsch catalysts, methods of making Fischer-Tropsch catalysts, processes of hydrogenating carbon monoxide, and fuels made using these processes. The invention provides the ability to hydrogenate carbon monoxide with low contact times, good conversion rates and low methane selectivities. In a preferred method, the catalyst is made using a metal foam support.

  17. Catalyst structure and method of fischer-tropsch synthesis

    DOEpatents

    Wang, Yong [Richland, WA; Vanderwiel, David P [Richland, WA; Tonkovich, Anna Lee Y [Pasco, WA; Gao, Yufei [Kennewick, WA; Baker, Eddie G [Pasco, WA

    2002-12-10

    The present invention includes Fischer-Tropsch catalysts, reactions using Fischer-Tropsch catalysts, methods of making Fischer-Tropsch catalysts, processes of hydrogenating carbon monoxide, and fuels made using these processes. The invention provides the ability to hydrogenate carbon monoxide with low contact times, good conversion rates and low methane selectivities. In a preferred method, the catalyst is made using a metal foam support.

  18. Diffusion limitations in Fischer-Tropsch catalysts

    SciTech Connect

    Post, M.F.M.; Van'tHoog, A.C.; Minderhoud, J.K.; Sie, S.T. . Lab.)

    1989-07-01

    The extent of diffusion limitations in the catalytic conversion of synthesis gas to hydrocarbons by the Fischer-Tropsch reaction has been established for a number of iron- and cobalt-based catalysts. The studies were performed in a fixed-bed microreactor system at temperatures in the range 473-523 {Kappa}. Variation of catalyst particle size in the range 0.2.-2.6 mm shows that the conversion of synthesis gas decreases considerably when the average particle size is increased. The effects of variation of particle size and pore diameter have been quantified with the Thiele model for diffusion limitations. Evidence has accumulated that the limited mobility of reactant molecules in the liquid-filled pores of Fischer-Tropsch catalysts is the main cause of retardation of the reaction rates. The experimentally determined reaction rates with various catalysts operated under different conditions show an excellent fit with the theoretical model.

  19. 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.

  20. Diffusion limitations in Fischer-Tropsch catalysts

    SciTech Connect

    Post, M.F.M.; Sie, S.T. Badhuisweg 3, 1031 CM Amsterdam )

    1988-01-01

    Indirect conversion of natural hydrocarbon resources such as natural gas into transportation fuels or chemicals usually involves the conversion to carbon monoxide and hydrogen (synthesis gas), followed by a catalytic conversion to the desired products via e.g. the Fischer-Tropsch (FT) reaction. In a fixed-bed mode of operation, the FT catalyst generally consists of particles of a few mm in size, for pressure-drop and heat-transfer considerations. To investigate whether diffusion limitations inside larger catalyst particles play a role during the synthesis reaction, the authors have made an extensive study using a number of iron- and cobalt-based catalysts, in which they have evaluated and quantified the effects of catalyst particle size and pore diameter on reaction rates. The effects due to variation of particle size and pore diameter have been quantified with the Thiele model for diffusion limitations.

  1. Reoxidation and deactivation of supported cobalt Fischer-Tropsch catalysts

    SciTech Connect

    Schanke, D.; Hilmen, A.M.; Bergene, E.

    1995-12-01

    The Fischer-Tropsch synthesis is an attractive possibility for conversion of natural gas into high quality liquid fuels. Due to its low water-gas shift activity, good activity/selectivity properties and relatively low price, cobalt is the choice of catalytic metal for natural gas conversion via Fischer-Tropsch synthesis. In the cobalt-catalyzed Fischer-Tropsch reaction, oxygen is mainly rejected as water. In this paper we describe the influence of water on supported cobalt catalysts. The deactivation of supported Co catalysts was studied in a fixed-bed reactor using synthesis gas feeds containing varying concentrations of water vapour.

  2. The optimally performing Fischer-Tropsch catalyst.

    PubMed

    Filot, Ivo A W; van Santen, Rutger A; Hensen, Emiel J M

    2014-11-17

    Microkinetics simulations are presented based on DFT-determined elementary reaction steps of the Fischer-Tropsch (FT) reaction. The formation of long-chain hydrocarbons occurs on stepped Ru surfaces with CH as the inserting monomer, whereas planar Ru only produces methane because of slow CO activation. By varying the metal-carbon and metal-oxygen interaction energy, three reactivity regimes are identified with rates being controlled by CO dissociation, chain-growth termination, or water removal. Predicted surface coverages are dominated by CO, C, or O, respectively. Optimum FT performance occurs at the interphase of the regimes of limited CO dissociation and chain-growth termination. Current FT catalysts are suboptimal, as they are limited by CO activation and/or O removal. PMID:25168456

  3. Reoxidation and deactivation of supported cobalt Fischer-Tropsch catalysts

    SciTech Connect

    Schanke, D.; Bergene, E.; Adnanes, E.

    1995-12-31

    As a result of the highly exothermic nature of the Fischer-Tropsch reaction, heat transfer considerations limit the maximum conversion per pass in fixed-bed processes, whereas slurry reactors can operate at higher conversions. During Fischer-Tropsch synthesis on cobalt catalysts, high conversions will generate high partial pressures of water at the reactor exit, due to the low water gas shift activity of cobalt. In addition, the extensive back-mixing in slurry reactors will give a relatively uniform concentration profile in the reactor, characterized by a high concentration of water and low reactant concentrations. From the commercial iron-catalyzed Fischer-Tropsch synthesis in fixed-bed (Arge) reactors it is known that the catalyst deactivates by oxidation of iron by CO{sub 2} and H{sub 2}O near the exit of the reactor. Although bulk oxidation of cobalt during Fischer-Tropsch synthesis is not thermodynamically favored, it was early speculated that surface oxidation of cobalt could occur during Fischer-Tropsch synthesis. The purpose of the present work is to describe the influence of water on the deactivation behavior of Al{sub 2}O{sub 3} supported cobalt catalysts. The possibility of cobalt oxidation during Fischer-Tropsch synthesis was investigated by model studies.

  4. Separation of Fischer-Tropsch wax from catalyst by supercritical extraction. Quarterly report, July 1, 1996 - September 30, 1996

    SciTech Connect

    Joyce, P.C.; Thies, M.C.; Sherrard, D.; Biales, J.; Kilpatrick, P.; Roberts, G.

    1996-12-31

    The objective of this research projects is to evaluate the potential of SCF extraction for separating the catalyst slurry of a Fischer- Tropsch (F-T) slurry bubble column (SBC) reactor into two fractions: (1) a catalyst-free wax containing less than 10 ppm particulate matter and (2) a concentrated catalyst slurry that is ready for recycle or regeneration. The wax will be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e. 200-300{degrees}C. Initial work is being performed using n-hexane as the solvent. The success of the projects depends on two major factors. First, the supercritical solvent must be able to dissolve the F-T wax; furthermore, the must be accomplished without entraining the solid catalyst. Second, the extraction must be controlled so as not to favor the removal of the low molecular weight wax compounds, i.e., a constant carbon-number distribution of the alkanes in the wax slurry must be maintained at steady-state column operation. The project includes three tasks (1) equilibrium solubility measurements, (2) thermodynamic modeling, and (3) process design studies.

  5. 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.

  6. 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.

  7. 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.

  8. Development and process evaluation of improved Fischer-Tropsch slurry catalysts. [Tenth] quarterly technical progress report, 1 January--31 March 1989

    SciTech Connect

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

    1989-12-31

    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.

  9. Separation of Fischer-Tropsch wax from catalyst using supercritical fluid extraction. Quarterly technical progress report, 1 January 1996--31 March 1996

    SciTech Connect

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

    1996-09-01

    The objective of this research project is to evaluate the potential of supercritical fluid extraction for separating the catalyst slurry of a Fischer-Tropsch (F-T) slurry bubble column (SBC) reactor into two fractions: (1) a catalyst-free wax containing less than 10 ppm particulate matter and (2) a concentrated catalyst slurry that is ready for recycle or regeneration. The wax will be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200--300 {degrees}C. Initial work is being performed using n-hexane as the solvent. The success of the project depends on two major factors. First, the supercritical solvent must be able to dissolve the F-T wax; furthermore, this must be accomplished without entraining the solid catalyst. Second, the extraction must be controlled so as not to favor the removal of the low molecular weight wax compounds, i.e., a constant carbon-number distribution of the alkanes in the wax slurry must be maintained at steady-state column operation. During this quarter work focused on task 1b, experimental measurement of selected model systems. Vapor-liquid equilibrium experiments for the n- hexane/squalane system, which we initiated in the previous quarter, were continued and results are discussed in this report.

  10. Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst. [Quarterly] report, June 30, 1988--September 30, 1988

    SciTech Connect

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

    1988-12-31

    This report details experiments performed on three different copper-based catalysts: Cu/Cr{sub 2}O{sub 3}, Cu/MnO/Cr{sub 2}O{sub 3} and Cu/ZnO/Al{sub 2}O{sub 3}. Of these three catalysts, the Cu/ZnO/Al{sub 2}O{sub 3} exhibits the greatest stability when slurried in octacosane. More than 1000 hours-on-stream indicate that the catalyst activity is not detrimentally affected by high pressure, high H{sub 2}/CO ratio, or the presence of alkenes. All of these are necessary stability characteristics for the water-gas shift catalyst, if it is to be used in combination with a cobalt Fischer-Tropsch catalyst. A review of documented reduction procedures for cobalt-based Fischer-Tropsch catalysts is presented.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst. [Quarterly] report, October 1, 1989--December 31, 1989

    SciTech Connect

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

    1989-12-31

    The rate of synthesis gas consumption over a cobalt FischerTropsch catalyst was measured in a well-mixed, continuous-flow, slurry reactor at 220 to 240{degrees}C, 0.5 to 1.5 MPa, H{sub 2}/CO feed ratios of 1.5 to 3.5 and conversions of 7 to 68% of hydrogen and 11 to 73% of carbon monoxide. The inhibiting effect of carbon monoxide was determined quantitatively and a Langmuir-Hinshelwood-type equation of the following form was found to best represent the results: -R{sub H{sub 2+Co}} = (a P{sub CO}P{sub H{sub 2}})/(1 + b P{sub CO}){sup 2}. The apparent activation energy was 93 to 95 kJ/mol. Data from previous studies on cobalt-based Fischer-Tropsch catalysts are also well correlated with this rate expression.

  16. Surface characterization of iron Fischer-Tropsch catalysts

    SciTech Connect

    Kuivila, C.S.; Butt, J.B.; Stair, P.C.

    1986-01-01

    In this paper the authors address XPS characterization of the iron phases associated with Fischer-Tropsch catalysts. Results obtained for single-phase metal, oxide, and carbide samples are presented. Methods for estimating the extent of carbide formation during low conversion synthesis, and the extent of catalyst oxidation at high conversions are illustrated. This approach is used to monitor the evolution of an initially reduced, unsupported iron catalyst during synthesis at low conversion levels.

  17. Novel Fischer-Tropsch slurry catalysts and process concepts for selective transportation fuel production: Quarterly technical progress report, 1 July 1985-30 September 1985

    SciTech Connect

    Carroll, W.E.; Cilen, N.; Motika, S.A.; Withers, H.P. Jr.

    1987-09-01

    Four catalysts were prepared. Silica was examined as a support for the standard Co/sub 2/(CO)/sub 8//Zr(OPr)/sub 4/ composition. A mixed Co/Fe catalyst on zirconated silica was prepared from Co/sub 2/(CO)/sub 8/ and Fe/sub 3/(CO)/sub 12/, rather than from the (FeCo/sub 3/(CO)/sub 12/)/sup -/ anion. The use of Ti in place of Zr as the promoter was examined with the silica support. Further work on alternate supports was completed with the preparation of Co/sub 2/(CO)/sub 8/ and Zr(OPr)/sub 4/ on MgO 3.6SiO/sub 2/. Gas-phase screening was completed on three catalysts during the quarter. The effect of increasing the cobalt loading from 4 to 11 wt % for the Co/Zr/Al/sub 2/O/sub 3/ composition was to improve the bulk activity but lower the specific activity and to slightly shift the hydrocarbon selectivity to higher molecular weight products. The use of silica as a support for the mixed Co/Fe catalyst also provided an improvement in the Fischer-Tropsch activity but did not enhance the water-gas shift activity. Three catalysts were screened in the slurry reactor. A kinetic data analysis program was developed to aid in the analysis of catalyst data from the laboratory reactor tests operating at steady state. The required specifications include reaction stoichiometry and kinetics, the necessary reactor operating parameters, inlet conditions and gas phase product concentrations. Options include choice of fixing or fitting kinetic parameters and regressing rate coefficients in a normalized or standard fashion. Data from the catalyst slurry screening tests and more importantly the extended tests will be routinely analyzed for kinetic correlations. 5 refs., 50 figs., 105 tabs.

  18. 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.

  19. 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.

  20. Technology development for iron and cobalt Fischer-Tropsch catalysts

    SciTech Connect

    Davis, B.H.

    1999-11-01

    The impact of deuterium on the Fischer-Tropsch (FT) synthesis was studied with a precipitated iron catalyst in the slurry phase. Deuterium has been used by several research groups to better understand the mechanism of CO hydrogenation. Inverse (k{sub H}/k{sub D} < 1), normal (k{sub H}/k{sub D} > 1) and no isotope effect (k{sub H}/k{sub D} = 1) have been reported. The conflicting results are thought to arise because rate of reaction is a combination of kinetic and equilibrium factors. In summary, the presence of boron produced only minor changes on the properties of the cobalt catalyst. In earlier studies, it was shown that the presence of boron made the catalyst less susceptible to poisoning by sulfur. Steady-state supercritical Fischer-Tropsch synthesis was studied in the work using a fixed-bed reactor and an unpromoted Co/SiO{sub 2} catalyst. This serves as the baseline for promoted catalyst studies. A pentane-hexane mixture was used as the supercritical solvent. Overall reactor pressure, syngas partial pressure and contact time were kept constant to obtain a valid comparison of the impact of solvent density in the catalytic activity and selectivity. Three different partial pressures of the mixture were chosen based on the density-pressure curve in order to investigate the pressure tuning effect to Fischer-Tropsch synthesis near critical region.

  1. 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.

  2. 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.

  3. Moessbauer spectroscopy studies of iron-catalysts used in Fischer-Tropsch (FT) processes. Quarterly technical progress report, October 1, 1996--December 31, 1996

    SciTech Connect

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

    1996-12-31

    The U.S. Department of Energy has currently a program to develop Fischer-Tropsch catalysts which are active at low H{sub 2}/Co ratio of 0.67. The Center for Applied Energy Research, University of Kentucky and Texas A&M University have been developing Fischer- Tropsch catalysts which are active at a low H{sub 2}/Co ratio of 0.67. It is of interest to find out any relationships that may exist between the iron phases that are produced during activation and FT synthesis and the activity of the catalysts. Moessbauer spectroscopy investigations were carried out on 32 iron-base catalysts during the period under review. Eleven catalysts withdrawn from slurry type of reactors during and at the end of FT synthesis were received from the University of Kentucky. Twenty one catalysts withdrawn at the end of the run from both the slurry and fixed-bed reactors were received from Texas A&M University.

  4. 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.

  5. Catalyst and reactor development for a liquid phase Fischer-Tropsch process. Quarterly technical progress report, 1 October-31 December 1980

    SciTech Connect

    Brockington, J.W.; Dyer, P.N.; Pierantozzi, R.; Bauer, J.V.

    1981-01-01

    Air Products, under contract to the DOE, has begun a three year program in Catalyst and Reactor Development for a Liquid Phase Fischer-Tropsch Process. The program contains four major tasks: (1) Project Work Plan, (2) Slurry Catalyst Development, (3) Slurry Reactor Design Studies, and (4) Pilot Facility Design. Task 1 has been completed with the preparation of a Project Work Plan describing in detail the methods and technical approach to be used. Task 2 has four sub-tasks. The first segment of the background studies deals with the effect of metal particle size on product selectivity and is included in this report. Based on these background studies, ten of twenty modified traditional Fischer-Tropsch catalysts to be prepared and slurry phase tested have been identified. Slurry reactor specifications have been finalized and a comprehensive product analysis scheme and data handling system has been established. Forty of the fifty supported metal cluster catalysts to be prepared and gas phase screened have been identified. Two metal cluster catalysts have been prepared. A detailed experimental plan for the first phase of Task 3 using a 5-inch diameter cold flow reactor simulator has been completed.

  6. Separation of Fischer-Tropsch wax from catalyst using supercritical fluid extraction. Quarterly technical progress report, July 1, 1995--September 31, 1995

    SciTech Connect

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

    1996-02-01

    Programming and testing of the highly complex Statistical Associating Fluid Theory (or SAFT) equation of state is essentially complete. As an accuracy check, results from our program were compared and found to be in excellent agreement with those of two other research groups (one in the US and two in Europe) for both a nonassociating (methane-hexadecane) and an associating (carbon dioxide-methanol) system. This equation is being used to model the solubility our model Fischer-Tropsch compounds in supercritical solvents such as hexane. SAFT has been chosen for this work because of its fundamental rigor. Therefore, extension of our model compound results to the poorly defined Fischer-Tropsch waxes should be more successful compared to more empirical equations such as Peng-Robinson. Computer-controlled automation of one of our dynamic supercritical fluid (SCF) extraction apparatus is complete. The apparatus collects samples automatically, dramatically reducing operator manpower and fatigue, and is also capable of controlling the operating pressure more precisely (i.e., within {plus_minus}2 psi). This apparatus (SFE I) will be used for future experiments with actual Fischer-Tropsch waxes. Modification/construction of another apparatus (SCF II) that will be used for our model component-SCF phase equilibria/solubility studies is nearly complete; it is currently being leak-tested. This apparatus was built to handle the low mass flow rates that will be required when measuring solubility data for the more expensive model compounds, such as n-C40. Anticipated results for the next quarter include VLE measurements for hexane-squalane at temperatures to 573 K.

  7. 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.

  8. 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.

  9. Polymer bound Fischer-Tropsch catalysts

    SciTech Connect

    Hsu, W.-L.; Kurr, R.J.; Maly, N.A.; Parker, D.K.; Stozier, R.W.

    1986-06-24

    A process is described for the conversion of synthesis gas to hydrocarbons which comprises contacting the synthesis gas with a catalyst in the vapor phase at a temperature from 175/sup 0/C to 300/sup 0/C and a pressure of at least 1000 kPa. The improvement described here comprising using as the catalyst a catalyst.

  10. The surface chemistry of iron Fischer-Tropsch catalysts

    SciTech Connect

    Dwyer, D.J.; Hardenburgh, J.H.

    1986-04-01

    The indirect conversion of coal to liquid hydrocarbons via steam gasification followed by synthesis gas (CO/H/sub 2/) chemistry has been the subject of intensive study for a number of decades. A key technological challenge facing researchers in this area is control over the product distribution during the hydrocarbon synthesis step. In the case of iron Fischer-Tropsch catalysts, it has been known that the addition of alkali to the metal catalyst has a significant impact on the product distribution. Iron catalysts treated with alkali produce less methane more alkenes and higher molecular weight products. In spite of numerous investigations, the details of this promotional effect are not understood on a molecular level. To explore the role of alkali in the surface chemistry of iron catalysts, the authors have carried out a combined surface science and catalytic kinetic study of a model iron catalyst with and without surface alkali.

  11. Technology development for iron Fischer-Tropsch catalysts. Quarterly technical progress report for period ending December 1993

    SciTech Connect

    O`Brien, R.J.; Xu, Liguang; Bi, Xiangxin; Eklund, P.; Davis, B.H.

    1993-12-31

    Conversion data as a function of time of synthesis for the two catalysts are shown in Figures 2 and 3. In general the precipitated catalyst is more active than the iron carbide catalyst with syn-gas conversions starting at 80% as compared to 50% for the latter; however, both catalysts deactivated with increasing reaction time. A comparison of the C{sub 2}, C{sub 3} and C{sub 4} olefin selectivities at 26% CO conversion (precipitated catalyst-336 hr of synthesis, iron carbide catalyst-122 hr of synthesis) are shown in Figure 4. Surprisingly the precipitated catalyst had a higher olefin content than the iron carbide catalyst. It has been reported that a similar iron carbide catalyst has higher selectivity for the production of olefins than a ``conventionally prepared`` Fe/Co catalyst. The discrepancy may be due in part to comparing the olefin selectivity of the two catalysts at different conversions. Their ``conventional catalyst`` had a C{sub 2}{minus}C{sub 4} olefin content of 37% at 72% conversion compared to 86% olefin at 55% conversion for the iron carbide catalyst. In general the olefin selectivity of a catalyst is highest at low conversions. The iron carbide catalyst of this study produces more hydrocarbons than the precipitated catalyst; furthermore, it produces a higher fraction of C{sub 3} + (86% vs. 84%) and C{sub 5}+ (67% vs. 61%) hydrocarbons (Figure 5). Correspondingly, the iron carbide catalyst produces less methane and ethane than the precipitated catalyst (Figure 6). These hydrocarbon and C{sub 5}+ selectivities are similar to those reported earlier.

  12. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, January 1, 1993--March 31, 1993

    SciTech Connect

    Bukur, D.B.

    1993-04-20

    The objective of proposed research is the 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. Studies of both supported and unsupported iron/copper/potassium catalysts are presented.

  13. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, April 1, 1993--June 31, 1993

    SciTech Connect

    Bukur, D.B.

    1993-07-15

    The objective of proposed research is the 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. Studies of both supported and unsupported iron/copper/potassium catalysts are presented.

  14. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, October 1, 1992--December 31, 1992

    SciTech Connect

    Bukur, D.B.

    1993-01-29

    The objective of proposed research is the 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. Studies of both supported and unsupported iron/copper/potassium catalysts are presented.

  15. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, April 1, 1992--June 30, 1992

    SciTech Connect

    Bukur, D.B.

    1992-07-15

    The objective of proposed research is the 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. Studies of both supported and unsupported iron/copper/potassium catalysts are presented.

  16. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, July 1, 1992--September 30, 1992

    SciTech Connect

    Bukur, D.B.

    1992-10-23

    The objective of proposed research is the 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. Studies of both supported and unsupported iron/copper/potassium catalysts are presented.

  17. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, July 1, 1993--September 30, 1993

    SciTech Connect

    Bukur, D.B.

    1993-10-21

    The objective of proposed research is the 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. Studies of both supported and unsupported iron/copper/potassium catalysts are presented.

  18. 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.

  19. Fischer-Tropsch cobalt catalyst development

    SciTech Connect

    Oukaci, R.; Goodwin, J.G. Jr.; Marcelin, G.; Singleton, A.

    1994-12-31

    Based on the information provided in patents assigned to Gulf, Shell, Exxon, and Statoil, a series of catalysts has been prepared consisting of 12-20 wt% cobalt, a second metal promoter (Ru or Re), and an oxide promoter such as lanthana, zirconia, or alkali oxide, the support being alumina, silica, or titania. All catalysts have been extensively characterized by different methods. The catalysts have been evaluated in terms of their activity, selectivity both in a fixed bed reactor and in a slurry bubble column reactor, and the results correlated with their physico-chemical properties.

  20. Development and process evaluation of improved Fischer-Tropsch slurry catalysts: Quarterly technical progress report, 1 July-30 September 1987

    SciTech Connect

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

    1987-12-21

    Nine runs in fixed bed reactors were performed during this period using the precipitated iron catalysts prepared in our laboratory. These tests were made to investigate the effect of copper and potassium promoters on catalyst activity and selectivity at various process conditions. Catalysts with 0 and 0.05 parts potassium were less stable and less active than catalysts with higher potassium loadings. Potassium and copper also influence product selectivity. One additional run was also made with United Catalyst, Inc. fused iron catalyst as a repeat of a previous run. The investigation of catalyst activation/reduction procedures was begun in this period. The reductant type, temperature and pressure of the reduction will be studied as parameters, using a 100 Fe/3.0 Cu/0.2 K catalyst. Surface area and pore size distribution measurements have been continued for the doubly promoted catalysts. Temperature programmed reduction (TPR) has also been applied to the doubly promoted catalysts. The effects of copper and potassium on catalyst reduction are similar to those observed for singly promoted catalysts. Work on isothermal reduction tests has also been performed. The promotional effect of copper on iron reduction is also seen at isothermal conditions, in agreement with the TPR results. Also, it was found that isothermal CO reduction occurs more rapidly than with H/sub 2/. The trapping scheme of both fixed bed reactors and the existing slurry reactor have been modified to allow for the high pressure collection of products. Improvements in the temperature control of the fixed bed reactors have been made. A new slurry reactor, including a computer data acquisition/control system, has been built. The preliminary tests of this system have been completed. 7 refs., 29 figs., 16 tabs.

  1. Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst. [Quarterly] report, October 1, 1988--December 31, 1988

    SciTech Connect

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

    1988-12-31

    A cobalt Fischer-Tropsch catalyst (CO/MgO/silica) was reduced and slurried in combination with reduced Cu/ZnO/Al{sub 2}0{sub 3} water-gas-shift catalyst. Combined catalyst system was run at fixed process conditions for more than 400 hours. The system showed stable selectivity. The Cu/ZnO/Al{sub 2}0{sub 3} water-gas-shift catalyst remained reasonably active in the presence of the cobalt catalyst. Hydrocarbon selectivity of the cobalt and Cu/ZnO/Al{sub 2}0{sub 3} catalyst system compared favorably to selectivity of iron-based catalysts. Methane selectivity was slightly higher for the cobalt-based system, but C{sub 5}{sup +} selectivity was essentially the same. The hydrocarbon product distribution appeared to exhibit a double-a behavior. a{sub 1} was near 0.80 which is higher than that of iron catalysts, while a{sub 2} was calculated to be 0.86 which is somewhat lower than would be typical for an iron-based catalyst.

  2. 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.

  3. 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.

  4. 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.

  5. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 October 1989--31 December 1989

    SciTech Connect

    Bukur, D.B.; Patel, S.A.

    1990-01-15

    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.

  6. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 July 1990--30 September 1990

    SciTech Connect

    Bukur, D.B.

    1990-10-29

    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.

  7. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 April 1991--30 June 1991

    SciTech Connect

    Bukur, D.B.

    1991-07-19

    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.

  8. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 October 1990--31 December 1990

    SciTech Connect

    Bukur, D.B.

    1991-01-25

    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.

  9. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 July 1991--30 September 1991

    SciTech Connect

    Bukur, D.B.

    1991-10-28

    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.

  10. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 January 1991--31 March 1991

    SciTech Connect

    Bukur, D.B.

    1991-04-24

    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.

  11. 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.

  12. Technology development for iron Fischer-Tropsch catalysts

    SciTech Connect

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

    1991-01-01

    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 scale up procedure for large-scale synthesis of such catalysts for process development and long-term testing in slurry bubble-column reactors. The catalyst performance target in the slurry bubble-column reactor is 88% CO + H{sub 2} conversion at a minimum space velocity of 2.4 NL/hr/gFe. Typical feed used to attain this level of conversion is preferred to have H{sub 2} and CO in the molar ratio of 0.5 to 1.0. The desired sum of methane and ethane selectivities is no more than 4%, and the conversion loss per week is not to exceed 1%.

  13. Technology development for iron Fischer-Tropsch catalysts

    SciTech Connect

    Not Available

    1991-01-01

    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 catalyst for process development and long-term testing in slurry bubble-column reactors. With a feed containing H{sub 2} and CO in the molar ratio of 0.5 to 1.0, the catalyst performance target in the slurry bubble-column reactor 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%.

  14. Technology development for iron Fischer-Tropsch catalysts

    SciTech Connect

    Not Available

    1990-01-01

    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 scale-up procedure for large-scale synthesis of such catalysts for process development and long-term testing in slurry bubble column reactors. With a feed containing H{sub 2}:CO in the ratio of 0.5 to 1.0, the catalyst performance target in the slurry bubble column reactor is 88% CO + H{sub 2}conversion at a minimum space velocity of 2.4 NL/h/gFe. The methane + ethane selectivity is desired to be no more than 4% and the conversion loss per week is not to exceed 1%.

  15. Moessbauer spectroscopy studies of iron-catalysts used in Fischer-Tropsch (FT) processes. Quarterly technical progress report, January--March, 1995

    SciTech Connect

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

    1995-10-01

    Moessbauer spectroscopy investigations were carried out on 14 iron-based catalysts during the period under review. The catalyst 100Fe/4.4Si/0.71K (all atomic ratios) was subjected to activation first in syngas and subsequently in CO gas atmosphere. Fischer-Tropsch (FT) synthesis was carried out on the above catalyst. Another catalyst 100Fe/4.4Si/2.6Cu/0.71K (all atomic ratios) activated in syngas and subjected to FT synthesis was also studied to understand the effect of added Cu on the phase distribution and its effect on the FT activity. The following trends were observed: (1) activation of the catalyst in syngas, H{sub 2}/CO, lead to the formation of Fe{sub 3}O{sub 4} and no carbides were formed, the FT activity was found to be low at 9--12% (H{sub 2}+CO) conversion; (2) activation of the catalyst in CO for 22hrs lead to the formation of 33% of {chi}-carbide and the FT activity was found to be high at 88% maximum; (3) addition of copper to the catalyst has improved the FT activity for those catalysts pretreated in syngas at elevated pressures.

  16. Iron Fischer-Tropsch catalysis: Properties of an ultrafine iron oxide catalyst. Quarterly progress report, July--September 1992

    SciTech Connect

    Xu, Liguang; Bao, Shiqi; O`Brien, R.; Houpt, D.; Davis, B.H.

    1992-12-31

    A commercial Fe oxide with a particle size of 3 nm is now available. The FT requires considerable time on stream before steady state conditions are attained. Since it is desirable to obtain FT data for the smaller ultrafine Fe oxide catalysts at larger times on steam, data for operation up to 6 months were collected using slurry phase. Results show that the ultrafine Fe oxide maintain catalytic activity for a 150-day operating period. Addition of 0.5% K increased the activity; after 56 days, the activity had declined to and below that of unpromoted catalyst. Neither the unpromoted nor K-promoted catalyst exhibited good selectivity for alkenes.

  17. 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.

  18. Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 January 1992--31 March 1992

    SciTech Connect

    Bukur, D.B.

    1992-04-24

    Three tests (two fixed bed and one stirred tank slurry reactor) were completed during the reporting period. Also, the work on catalyst characterization by different techniques (atomic absorption, BET surface area and pore size distribution and x-ray powder diffraction).The performance of a precipitated iron catalyst with nominal composition lOOFe/0.3Cu/0.8K has been evaluated in two fixed bed reactor tests designated FB-0142 and FB-0352 following pretreatment with syngas (H{sub 2}/CO=0.67) at 280{degree}C, 3Nl/g-cat/h and atomspheric pressure for 8 hours. Flow interruption occurred in the first test (FB-0142) at about 72h on stream, and the second test (FB-0352) was to assess any potential adverse effects of this flow interruption on performance of the catalyst. The catalyst was tested at 250{degree}C, 200 psig, 2Nl/g-cat/h using syngas of the same composition as that employed during the pretreatment. Initial conversions in both tests were high (about 84%) but the catalyst deactivated fairly rapidly. The (H{sub 2} + CO) conversion at the end of the first test (120h on stream) was about 52%, whereas the syngas conversion at the end of the second test (150h) was about 55%, indicating that the brief flow interruption during test FB-0142 had resulted in higher deactivation rate. Hydrocarbon selectivities in both tests were similar and their average values werr: (CH{sub 4})=4.7, (C{sub 2}{minus}C{sub 4})=19.5, (C{sub 5}{minus}C{sub 11})=25.3 and C{sub 12}{sup +}=50.5 wt%.

  19. Fischer-tropsch synthesis in supercritical fluids. Quarterly technical progress report, October 1, 1994--December 21, 1994

    SciTech Connect

    Akgerman, A.; Bukur, D.B.

    1995-01-31

    Progress reports are presented for the following two tasks: (1) diffusion coefficients of F-T products in supercritical fluids; and (2) Fischer-Tropsch reaction related studies. The objectives for this quarter for task 1 were to measure molecular diffusion coefficients and effective diffusivities at the same conditions. The objectives for task 2 were to conduct two additional tests with the Ruhrchemie catalyst and a catalyst synthesized in our laboratory under supercritical conditions.

  20. 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.

  1. Separation of Fischer-Tropsch wax from catalyst using supercritical fluid extraction. Quarterly technical progress report, April 1, 1996--June 30, 1996

    SciTech Connect

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

    1996-11-01

    The objective of this research project is to evaluate the potential of SCF extraction for separating the catalyst slurry of a Fischer- Tropsch (F-T) slurry bubble column (SBC) reactor into two fractions: (1) a catalyst-free wax containing less than 10 ppm particulate matter and (2) a concentrated catalyst slurry that is ready for recycle or regeneration. The wax will be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300{degrees}C. Initial work is being performed using n-hexane as the solvent. The success of the project depends on two major factors. First, the supercritical solvent must be able to dissolve the F-T wax; furthermore, this must be accomplished without entraining the solid catalyst. Second, the extraction must be controlled so as not to favor the removal of the low molecular weight wax compounds, i.e., a constant carbon-number distribution of the alkanes in the wax slurry must be maintained at steady-state column operation. To implement our objectives, the following task structure is being implemented: Task 1 equilibrium solubility measurements; Task 2 thermodynamic modeling; and Task 3 process design studies. Progress reports are presented for each task.

  2. Improved Fischer-Tropsch Synthesis catalysts for indirect coal liquefaction

    SciTech Connect

    Tong, G.T.; Wilson, R.B.; McCarty, J.G.

    1987-01-01

    The monoruthenium cluster catalyst with a molecular sieve support and the tetraruthenium cluster catalyst with a sodium-Y zeolite support have been examined for Fischer-Tropsch Synthesis (FTS) performance at high pressure (6.9 MPa) in a slurry reactor and compared with conventional ruthenium with an alumina support and clean fused iron catalysts. Of the four catalysts tested, only the conventional ruthenium catalyst exhibited a chain growth factor of 0.88 and a methane selectivity of 6.6%, which are typical of slurry reactor results reported for iron catalysts under similar conditions. The other three catalysts tested showed low chain growth factors (ranging from 0.44 to 0.57) and high methane selectivity (ranging from 20 to 32%). A cobalt catalyst with approximately 50% sulfur coverage was prepared and tested for FTS activity and selectivity at ambient pressure and compared with the FTS performance of the clean and fully sulfided cobalt catalysts. The introduction of sulfur caused a decrease in methane selectivity and an increase in olefin selectivity with only a moderate decline in activity. 1 ref., 2 tabs.

  3. Catalyst and reactor development for a liquid-phase Fischer-Tropsch process. Quarterly technical progress report, 1 January 1982-31 March 1982

    SciTech Connect

    Dyer, P. N.; Pierantozzi, R.; Brian, B. W.; Bauer, J. V.

    1982-04-01

    This report describes work on Catalyst and Reactor Development for a Liquid Phase Fischer-Tropsch Process. The program contains four major tasks: (1) Project Work Plan, (2) Slurry Catalyst Development, (3) Slurry Reactor Design Studies, and (4) Pilot Facility Design. Two modified conventional catalysts were screened in the gas phase, and the improved results gave directions for further development work. Three slurry tests were run. The first, a 15 wt % slurry of a coprecipitated catalyst, showed non-standard Schulz-Flory product distributions, with a significant increase in C/sub 9/+ hydrocarbons. The second, a 19 wt % slurry of a support catalyst, also showed large deviations from the standard Schulz-Flory product, with a high selectivity for C/sub 10/-C/sub 25/ hydrocarbons. Compared to a previous gas phase test, however, CH/sub 4/ yields were higher and the activity lower. A third slurry test of a supported cluster catalyst also showed a lower activity than in the gas phase. Oil analysis indicates that the reduction of activity observed for supported metal catalysts in the slurry compared to the gas phase may be due to poisoning by an oil component. An alternative oil will therefore be utilized for future tests. Seven supported cluster catalysts were synthesized and six were screened in the gas phase. In two cases, an increased yield of C/sub 10/+ products was observed, dependent upon the reaction conditions. Another showed a product selectivity that could be shifted between oxygenates and hydrocarbons. Gas hold-up and solids dispersion measurements in the 5'' column were completed for the 0 to 5 ..mu..m and 45 to 53 ..mu..m iron oxide/isoparaffin, and the 45 to 53 ..mu..m and 90 to 115 ..mu..m silica/isoparaffin systems. The gas hold-up results were correlated by statistical analysis.

  4. 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.

  5. 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.

  6. 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.

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

    SciTech Connect

    Burtron H. Davis

    1999-04-30

    The impact of activation procedure on the phase composition of precipitated iron Fischer-Tropsch (FT) catalysts has been studied. Catalyst samples taken during activation and FT synthesis have been characterized by Moessbauer spectroscopy. Formation of iron carbide is necessary for high FT activity. Hydrogen activation of precipitated iron catalysts results in reduction to predominantly metallic iron and Fe{sub 3}O{sub 4}. Metallic iron is not stable under FT 3 4 conditions and is rapidly converted to {epsilon}{prime}-Fe{sub 2.2}C. Activation with carbon monoxide or syngas 2.2 with low hydrogen partial pressure reduces catalysts to {chi}-Fe{sub 5}C{sub 2} and a small amount of 5 2 superparamagnetic carbide. Exposure to FT conditions partially oxidizes iron carbide to Fe{sub 3}O{sub 4}; however, catalysts promoted with potassium or potassium and copper maintain a constant carbide content and activity after the initial oxidation. An unpromoted iron catalyst which was activated with carbon monoxide to produce 94% {chi}-Fe{sub 5}C{sub 2}, deactivated rapidly as the carbide was oxidized to Fe{sub 3}O{sub 4}. No difference in activity, stability or deactivation rate was found for {chi}-Fe{sub 5}C{sub 2} and {epsilon}{prime}-Fe{sub 2.2}C.

  8. Catalyst and reactor development for a liquid-phase Fischer-Tropsch process. Quarterly technical progress report, 1 January 1983-31 March 1983

    SciTech Connect

    Dyer, P.N.; Pierantozzi, R.; Brian, B.W.; Nordquist, A.F.; Parsons, R.L.

    1983-09-01

    Two major tasks continued in the APCI/US DOE contract, Catalysts and Reactor Development for a Liquid Phase Fischer-Tropsch Process: (1) Slurry Catalyst Development; and (2) Slurry Reactor Design Studies. The first extended slurry test was continued using a proprietary catalyst. The results showed that it was possible to produce yields in the diesel fuel region equal to or greater than the Schulz-Flory maximum, without further optimization. Low deactivation rates were observed. Kinetic rate constants were derived from the CSTR experiments, and used in a computer simulation to predict conversions from bubble column operation under Rheinpreussen conditions. Short term (21 day) slurry tests were carried out on two other catalysts, optimized by the screening program. Parametric gas phase screening results were concluded for two additional modified conventional catalysts, and the optimum preparation and activation methods for diesel fuel selectively were chosen. In the hydrodynamic studies, work in the 5'' column was completed with measurements on the Fe/sub 2/O/sub 3//water slurries. In the 12'' column, fitted with 7 heat transfer tubes, hydrodynamic parameters were determined for slurries of Fe/sub 2/O/sub 3/ in paraffin and water, and SiO/sub 2/ in water. Gas holdups were close to the Akita and Yoshida correlation for the hydrocarbon slurries, but lower for the aqueous ones. Solid concentration profiles, modelled by the sedimentation model, gave evidence of particle agglomeration in SiO/sub 2//hydrocarbon slurries, underlining the need to use chemically similar slurries in cold-flow modelling work. In the 5'' column, solid and liquid dispersion coefficients were found to be equal.

  9. The development of a selective ruthenium Fischer-Tropsch catalyst

    SciTech Connect

    Abrevaya, H.

    1989-01-01

    A new stable Fischer-Tropsch catalyst with very high selectivity to distillate fuels and with low light ends production was developed. This catalyst, which was made by a reverse micelle technique, contains 2.8% (by weight) ruthenium in the form of 4--6 nm particles on alumina and a proprietary modifier. The new modified ruthenium catalyst did not noticeably deactivate during 814 hours at about 80% CO conversion, 2H{sub 2}:1 CO feed ratio, 208{degree}C at inlet, 62 atm and 150 gas hourly space velocity. In order to determine the catalyst's tolerance, the operational severity was increased between 814 hours and 1700 hours by increasing the temperature and space velocity to 225{degree}C at inlet and to 205 hr{sup {minus}1}, respectively. A deactivation rate of about 0.016%/hour was measured under these more severe conditions at about 70% conversion level. These results with the new modified ruthenium catalyst compare favorably with those reported for the two commercial Sasol processes. The Arge process makes approximately 38% distillate fuel with 14--18% light ends, while the Synthol process makes about 48% distillate with 38% light ends. 82 refs., 360 figs., 66 tabs.

  10. 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.

  11. Separation of Fischer-Tropsch wax from catalyst using supercritical fluid extraction. Quarterly technical progress report, 1 October 1995--31 December 1995

    SciTech Connect

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

    1996-06-01

    The objective of this research project is to evaluate the potential of supercritical fluid (SCF) extraction for separating the catalyst slurry of a Fischer-Tropsch slurry bubble column (SBC) reactor into two fractions: (1) a catalyst-free wax containing less than 10 ppm particulate matter and (2) a concentrated catalyst slurry that is ready for recycle or regeneration. The wax will be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300{degrees}C. Initial work is being performed using n-hexane as the solvent. During the reporting period, work on the small-scale, continuous-flow apparatus continued. Initial experiments have been performed on a binary mixture of n-hexane (solvent) and squalane (model compound) at 200{degrees}C. A total of fifteen samples were collected at 135, 160, and 208 psig, with pressures being controlled to within {plus_minus}2 psi. Results indicate that the equilibrium phase compositions can in principle be measured to a reproducibility of {plus_minus}0.5% in the squalane-rich bottomphase and {plus_minus}2% in the hexane-rich top phase, with respect to the minor component. However, other data measured at these same conditions at another time exhibited scatter that was as much as 5 times greater. We believe that improvements in (1) the method of preheating the feed to the view cell/phase separator and to (2) the sample collection technique are required before data of high accuracy can consistently be generated. The apparatus modifications required to effect these improvements are currently underway and should be completed by the middle of February.

  12. Fischer-Tropsch Synthesis on ALD-synthesized Catalysts

    NASA Astrophysics Data System (ADS)

    Van Norman, Staci A.

    Cobalt catalysts were prepared on porous Al2O 3 and W/Al2O3 supports by atomic layer deposition (ALD) that used sequential reactions of cobaltocene (CoCp2) and H 2 at 483 to 523 K. This preparation method avoided formation of an intermediate oxide, so the catalysts could be activated at lower temperatures. Some of these catalysts had CO reaction rates per g of Co in Fischer-Tropsch synthesis (FTS) that were three times those reported for Co catalysts prepared by incipient wetness. The FTS reacts CO and H2 to form hydrocarbon liquids that can used as synthetic fuels. The rate of FTS depended on the number of ALD cycles, and catalysts prepared with one cycle had activities equivalent to incipient wetness Co catalysts; the highest reaction rate per g of catalyst was obtained for catalysts prepared using four ALD cycles. Two types of Co were observed on the alumina surface using TEM: Co particles with diameters between 0.6 and 1.8 nm (75% were smaller than 1 nm), and Co crystalline planes that were as large as 35 nm. Cobalt catalysts prepared by ALD retained adsorbed ligands that appeared to be stable for at least eight months at room temperature. Tungsten was deposited onto porous Al2O 3 by ALD to provide a catalyst support with higher thermal conductivity because the FTS reaction is highly exothermic. The W indeed increased thermal conductivity, and the resulting supports were used for Co ALD following deposition of an Al2O3 ALD layer. However, although Co deposits on ALD Al2O3, the Co had no activity for FTS, apparently because the ALD Al2O3 was amorphous. In contrast ALD Al 2O3 that was heat treated at high temperature was partially crystalline and served as a support for an active FTS catalyst.

  13. Attrition Resistant Iron-Based Fischer-Tropsch Catalysts

    SciTech Connect

    Jothimurugesan, K.; Goodwin, J.G.; Spivey, J.J.; Gangwal, S.K.

    1997-03-26

    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 when using low CO/H{sub 2} ratio synthesis gases derived from modem coal gasifiers. This is because in addition to reasonable F-T activity, the FT catalysts also possess high water gas shift (WGS) activity. 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, making 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. The objectives of this research are to develop a better understanding of the parameters affecting attrition resistance 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. Catalyst preparations will be based on the use of spray drying and will be scalable using commercially available equipment. The research will employ among other measurements, attrition testing and F-T synthesis, including long duration slurry reactor runs in order to ascertain the degree of success of the various preparations. The goal is to develop an Fe catalyst which can be used in a SBCR having only an internal filter for separation of the catalyst from the liquid product, without sacrificing F-T activity and selectivity.

  14. Attrition Resistant Iron-Based Fischer-Tropsch Catalysts.

    SciTech Connect

    Jothimurugesan, K.; Goodwin, J.S.; Spivey, J.J.; Gangwal, S.K.

    1997-09-22

    The Fischer-Tropsch (F-T) reaction provides a way of converting coal-derived synthesis gas (CO and 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 when using low CO/H{sub 2} ratio synthesis gases derived from modern coal gasifiers. This is because in addition to reasonable F-T activity, the F-T catalysts also possess high water gas shift (WGS) activity. 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, making 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. The objectives of this research are to develop a better understanding of the parameters affecting attrition resistance 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. Catalyst preparations will be based on the use of spray drying and will be scalable using commercially available equipment. The research will employ among other measurements, attrition testing and F-T synthesis, including long duration slurry reactor runs in order to ascertain the degree of success of the various preparations. The goal is to develop an Fe catalyst which can be used in a SBCR having only an internal filter for separation of the catalyst from the liquid product, without sacrificing F-T activity and selectivity.

  15. ATTRITION RESISTANT IRON-BASED FISCHER-TROPSCH CATALYSTS

    SciTech Connect

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

    1999-03-29

    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 when using low CO/H2 ratio synthesis gases derived from modern coal gasifiers. This is because in addition to reasonable F-T activity, the F-T catalysts also possess high water gas shift (WGS) activity. 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, making 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. The objectives of this research are to develop a better understanding of the parameters affecting attrition resistance 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. Catalyst preparations will be based on the use of spray drying and will be scalable using commercially available equipment. The research will employ among other measurements, attrition testing and F-T synthesis, including long duration slurry reactor runs in order to ascertain the degree of success of the various preparations. The goal is to develop an Fe catalyst which can be used in a SBCR having only an internal filter for separation of the catalyst from the liquid product, without sacrificing F-T activity and selectivity. The effect of silica addition via coprecipitation and as a binder to a doubly promoted Fischer-Tropsch synthesis iron catalyst (100 Fe/5 Cu/4.2 K) was studied. The catalysts were prepared by coprecipitation, followed by binder addition and drying in a 1 m

  16. XPS characterization of iron Fischer-Tropsch catalysts

    SciTech Connect

    Kuivila, C.S.; Stair, P.C.; Butt, J.B.

    1986-04-01

    Analysis of Fe(2p) XPS and iron Auger spectra, combined with C(1s) XPS measurements, provides a valuable technique for studying the compositional behavior of Fischer-Tropsch catalysts. The extent of catalyst oxidation during synthesis at high conversions may be estimated in terms of the area contribution of oxide phases to the Fe(2p) spectrum. Similarities between the metal and carbide core level spectra are likely to complicate the determination of these phases when oxides are present. Analysis of the metal and carbide contributions to the iron Auger spectrum provides an alternate method for monitoring surface carbide formation during low conversion synthesis. The ''surface compositions'' obtained in this manner are at best semi-quantitative, since the contribution of a particular phase to the XPS or Auger spectrum will depend on both the amount and distribution of that phase within the detected volume. In spite of this, the spectrum fitting technique should prove to be useful in characterizing the time and conversion dependent nature of the active catalyst surface.

  17. Technology development for iron Fischer-Tropsch catalysis. Quarterly technical progress report, October--December, 1994

    SciTech Connect

    1994-12-31

    Fischer-Tropsch catalysts must undergo a pretreatment in order to be active. As part of the authors comprehensive study to maximize the activity of iron based precipitated Fischer-Tropsch catalysts, they are currently attempting to optimize the activation procedure. Although they are able to achieve high activity using CO pretreatment, the catalysts tend to deactivate suddenly and rapidly after 500 hr of synthesis. Kolbel reports high CO conversion comparable to these results at a lower gas flow (2.4 vs. 3.4 nL/hr-g(Fe)); however, he achieved greater stability with conversions reported to be 90% after 1,400 hrs. One possibility for Kolbel`s higher stability could be due to the activation procedure. Herein are reported the initial results of a study to optimize the catalyst composition and the operating conditions for the iron based slurry phase Fischer-Tropsch synthesis when synthesis gas activation is utilized.

  18. ATTRITION RESISTANT IRON-BASED FISCHER-TROPSCH CATALYSTS

    SciTech Connect

    JAMES G. GOODWIN, JR.; JAMES J. SPIVEY; K. JOTHIMURUGESAN; SANTOSH K. GANGWAL

    1998-09-17

    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 when using low CO/H{sub 2} ratio synthesis gases derived from modern coal gasifiers. This is because in addition to reasonable F-T activity, the F-T catalysts also possess high water gas shift (WGS) activity. 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, making 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. The objectives of this research are to develop a better understanding of the parameters affecting attrition resistance 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. Catalyst preparations will be based on the use of spray drying and will be scalable using commercially available equipment. The research will employ among other measurements, attrition testing and F-T synthesis, including long duration slurry reactor runs in order to ascertain the degree of success of the various preparations. The goal is to develop an Fe catalyst which can be used in a SBCR having only an internal filter for separation of the catalyst from the liquid product, without sacrificing F-T activity and selectivity. The effect of silica addition via coprecipitation and as a binder to a doubly promoted Fischer-Tropsch synthesis iron catalyst (100 Fe/5 Cu/4.2 K) was studied. The catalysts were prepared by coprecipitation, followed by binder addition and drying in a 1

  19. The hydrocarbon selectivity of cobalt Fischer-Tropsch catalysts

    SciTech Connect

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

    1991-07-01

    A cobalt Fischer-Tropsch catalyst was studied in a continuous-flow, well-stirred slurry reactor at 220 to 240{degrees}C, 0.5 to 1.5 MPa, H{sub 2}/CO feed ratios between 1.5 and 3.5, H{sub 2} conversions between 6 and 68%, and CO conversions between 11 and 73%. Increasing space velocity (decreasing conversion) or decreasing reactor H{sub 2}/CO ratio decreased the yield of (undesired) C{sub 1} products and increased the yield of (desired) C{sub 10}+ products. Reactor temperature and pressure had little effect on the carbon number distribution. These findings are interpreted in terms of the extent of the readsorption of 1-alkenes into growing chains on the catalyst surface. The relative selectivity to 1-alkenes by the primary synthesis and secondary reaction of l-alkenes to n-alkanes and 2-alkenes depends on reactor H{sub 2}/CO ratio and CO concentration. 25 refs., 15 figs.

  20. TECHNOLOGY DEVELOPMENT FOR IRON AND CONBALT FISCHER-TROPSCH CATALYSTS

    SciTech Connect

    Burtron H. Davis

    2000-10-01

    The use of alkali promoters has been widely practiced. However, data to compare various promoters is limited for the iron-based catalysts and much of the available data were obtained at low pressure or under a variety of reaction conditions. The importance of the alkali promoter in determining catalytic activity, stability and selectivity merits a comparison of the promoters under suitable reaction conditions. The present study utilizes medium pressure synthesis conditions to compare the alkali promoters under the same reaction conditions and over a wide range of conversion levels. Iron-based Fischer-Tropsch (FT) catalysts undergo a series of phase transformations during activation and use. Activation with carbon monoxide or syngas typically results in the conversion of Fe{sub 2}O{sub 3} to Fe{sub 3}O{sub 4} and ultimately to one or more carbides. During FT synthesis, iron carbides can be oxidized to Fe{sub 3}O{sub 4} if the H{sub 2}O/H{sub 2} or CO{sub 2}/CO ratios are high enough. There has been considerable debate about the active phase of the FT synthesis. Some studies have indicated an active oxide species while most have supported a carbide species. Moessbauer spectroscopy has proven to be an effective technique for the analysis of iron-based FT catalysts. In situ Moessbauer studies have been reported; however, these studies have been performed at low pressure and low conversions. Studies performed at industrially relevant conditions have generally involved removing the catalyst from the reactor followed by passivation which, if not performed properly, will oxidize the catalyst. Herein are reported the Moessbauer results obtained on an unpromoted precipitated iron catalyst that was activated and reacted in a slurry phase, continuous stirred tank reactor at high conversion and under industrially relevant conditions.

  1. The renaissance of iron-based Fischer-Tropsch synthesis: on the multifaceted catalyst deactivation behaviour.

    PubMed

    de Smit, Emiel; Weckhuysen, Bert M

    2008-12-01

    Iron-based Fischer-Tropsch catalysts, which are applied in the conversion of CO and H2 into longer hydrocarbon chains, are historically amongst the most intensively studied systems in heterogeneous catalysis. Despite this, fundamental understanding of the complex and dynamic chemistry of the iron-carbon-oxygen system and its implications for the rapid deactivation of the iron-based catalysts is still a developing field. Fischer-Tropsch catalysis is characterized by its multidisciplinary nature and therefore deals with a wide variety of fundamental chemical and physical problems. This critical review will summarize the current state of knowledge of the underlying mechanisms for the activation and eventual deactivation of iron-based Fischer-Tropsch catalysts and suggest systematic approaches for relating chemical identity to performance in next generation iron-based catalyst systems (210 references). PMID:19020686

  2. 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

  3. Fischer-Tropsch slurry catalysts for selective transportation fuel production

    SciTech Connect

    Carroll, W.E.; Cilen, N.; Withers, H.P. Jr.

    1986-01-01

    The future use of coal as a source of conventional transportation fuel will depend on the development of an economical and energy efficient liquefaction process. Technologies that have been commercially proven or that are close to commercialization include the fixed- and fluidized-bed Fischer-Tropsch (FT) synthesis, methanol synthesis (fixed-bed and slurry-phase) and the Mobil methanol-to-gasoline process. Of these technologies, the Fischer-Tropsch hydrocarbon synthesis produces the widest slate of products and has been in operation for the longest period.

  4. Studying the fischer tropsch synthesis on alumina support cobalt base catalyst in fixed bed reactor

    NASA Astrophysics Data System (ADS)

    Oues, Adnan Khalil

    A Fischer-Tropsch catalyst composed of cobalt supported on alumina was prepared. This catalyst was cobalt/alumina (Co/AL2O3). The physical characterization of the catalyst was conducted using surface area analysis through the BET method, and particle size analysis. Fischer-Tropsch experiments were conducted in a fixed bed reactor. A flow rate of 100sml/min was selected based experimentally. Two temperatures were 330, and 350°C, and three different pressures as follows 145, 217.6, and 290 psig. The results were evaluated and studied based on conversion of hydrogen and carbon monoxide, in addition to selectivity of products.

  5. Low nitrogen iron-containing Fischer-Tropsch catalyst and conversion of synthesis gas therewith

    SciTech Connect

    Bell, W.K.; Haag, W.O.; Kirker, G.W.; Klocke, D.J.

    1987-08-11

    This patent describes a process for converting syngas to hydrocarbons comprising: (a) contacting an iron-containing Fischer-Tropsch catalyst with a syngas stream under conditions effective to achieve high conversion of the syngas to substantial amounts of C/sub 3//sup +/ carbon compounds; (b) contacting the effluent stream from (a) with a shape selective crystalline zeolite having a Constraint Index of about 1 to 12; and (c) recovering from the effluent stream of (b) gasoline and distillate materials; the improvement which comprises preparing the iron-containing Fischer-Tropsch catalyst by a process which continuously precipitates an aqueous solution containing iron nitrate with aqueous ammonia at a pH of about 6.5 to 6.9 and a temperature ranging from about 70/sup 0/ to 100/sup 0/C and thereafter washing the resulting precipitate with an aqueous wash solution to produce a Fischer-Tropsch catalyst containing less than about 500 ppm nitrogen.

  6. 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.

  7. 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.

  8. Effect of potassium promotion on iron-based catalysts for Fischer-Tropsch synthesis

    SciTech Connect

    Raje, A.P.; O`Brien, R.J.; Davis, B.H.

    1998-11-15

    The effect of potassium on Fischer-Tropsch catalyst activity, kinetic parameters, and selectivity has been investigated for a precipitated iron catalyst that was employed with low H{sub 2}/CO ratio synthesis gas. A wide range of synthesis gas conversions have been obtained by varying space velocities over catalysts with various potassium loadings. Differing trends in catalyst activity with potassium loading were observed depending on the space velocity of synthesis gas conversion. As potassium loading increased, the catalyst activity either decreased (low conversion), passed through a maximum (intermediate conversion), or increased (high conversion). This is shown to be a result of the increasing dependency of the Fischer-Tropsch synthesis on the hydrogen formed by the water-gas shift reaction with increasing synthesis gas conversions. Both the rate constant and the adsorption parameter in a common two-parameter Fischer-Tropsch rate expression decreased with potassium loading; therefore, observed maxima in Fischer-Tropsch rate with potassium loading can be due to the opposing influences of these parameters. The effect of potassium on alkene selectivity was dependent on the number of carbon atoms of the hydrocarbons as well as the carbon monoxide conversion level. The extent of isomerization of 1-alkene product decreased with potassium loading, while the selectivity to methane decreased only slightly with increasing potassium content at CO conversions about 50% and higher.

  9. Fischer-Tropsch kinetic studies with cobalt-manganese oxide catalysts

    SciTech Connect

    Keyser, M.J.; Everson, R.C.; Espinoza, R.L.

    2000-01-01

    An investigation was undertaken to establish the reaction mechanism for the Fischer-Tropsch reaction, in the presence of the water-gas shift reaction, over a cobalt-manganese oxide catalyst under conditions favoring the formation of gaseous, liquid, and solid (waxes) hydrocarbons (210--250 C and 6--26 bar). A micro-fixed-bed reactor was used with a cobalt-manganese oxide catalyst prepared by a coprecipitation method. An integral reactor model involving both Fischer-Tropsch and water-gas shift reaction kinetics was used to describe the overall performance. Reaction rate equations based on Langmuir-Hinshelwood-Hougen-Watson models for the Fischer-Tropsch reaction (hydrocarbon forming) and empirical reaction rate equations for the water-gas shift reaction from the literature were tested. Different combinations of the reaction rate equation were evaluated with the aid of a nonlinear regression procedure. It was found that a reaction rate equation for the Fischer-Tropsch reaction based on the enolic theory performed slightly better than a reaction rate equation based on the carbide theory. Reaction rate constants for the cobalt-manganese oxide catalyst are reported, and it is concluded that this catalyst also behaves very much like iron-based catalysts.

  10. 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.

  11. 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.

  12. Catalyst and reactor development for a liquid phase Fischer-Tropsch process. Quarterly technical progress report, 1 January-31 March 1984

    SciTech Connect

    Carroll, W.E.; Cilen, N.; Motika, S.A.

    1985-03-01

    In the fourteenth quarter work continued for two major tasks: (1) Slurry Catalyst Development, and (2) Proprietary Catalyst A Development. The proprietary catalyst A work is part of a contract modification, begun last quarter, to improve the activity and center the selectivity for diesel fuel products of this catalyst. The basis of this work stems from promising results during extended testing of this catalyst. Variation of catalyst pretreatment methods and promoter levels are intended. Slurry catalyst development - Parametric gas phase screening tests were concluded on a modified conventional catalyst and an optimum preparation and activation procedure chosen for diesel fuel selectivity. A short term (approx. = 21 day) slurry test of this catalyst exhibited appreciable activity, but poor selectivity for diesel fuel products. The selectivity varied strongly with CO/H/sub 2/ ratio, but even at CO/H/sub 2/ = 2.0, products were predominantly below C/sub 10/. Catalyst A development - Three tests were conducted this quarter to determine the effects of varying the promoter levels of catalyst A. In summary, the basecase catalyst composition of this catalyst remained to be the most selective for diesel fuel. In activity level, a catalyst A' out-performed the activity of all catalysts tested to date. Surface analysis studies are underway to aid in understanding these effects and in so doing, optimizing the promoter levels for maximum activity and diesel fuel selectivity. Gas phase screening tests were conducted on catalyst A to determine the effects of activation and pretreatment procedures on activity and product selectivity. In general, no appreciable differences in bulk activity and only slight differences in hydrocarbon distribution were observed in the three tests conducted.

  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 (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.

  14. 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.

  15. 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.

  16. Mössbauer investigations of the Fe-Cu-Mn catalysts for Fischer-Tropsch synthesis

    NASA Astrophysics Data System (ADS)

    Spânu, Viorica; Filoti, G.; Ilie, Ioana; Zamfirescu, Elena

    1990-07-01

    In the selective process of the syngas conversion to synthetic gasoline a bifunctional catalytic system has to be used. It was obtained by combination a Fischer-Tropsch catalyst with the HZSM-5 zeolite. The phase compositions of the precursor and the fresh catalyst were established as well as the optimum thermal treatment. The catalyst was reduced in pure H2 or in a H2+CO mixture. The influence of the reduction and reaction conditions on the catalyst structure was investigated.

  17. 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.

  18. 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.

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

    SciTech Connect

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

    1989-01-01

    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.

  20. Deactivation of slurry phase Fischer-Tropsch catalysts

    SciTech Connect

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

    1996-12-31

    The influence of the liquid medium on Fischer-Tropsch (F-T) chemistry has received only minimal attention in the literature. The focus of this investigation was to determine the impact of the liquid starting medium on syngas (H{sub 2}+CO) conversion in a 1-liter CSTR. The results of the work indicate a greater deactivation rate for the F-T reaction in heavier starting media, average carbon number {ge}48, versus a medium with an average carbon number of 28.

  1. Separation of Fischer-Tropsch from Catalyst by Supercritical Extraction.

    SciTech Connect

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

    1997-10-31

    The objective of this research project is 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}, will be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300{degrees}C. Initial work is being performed using n-hexane as the solvent.

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

    SciTech Connect

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

    1988-01-01

    This report details experiments performed on three different copper-based catalysts: Cu/Cr[sub 2]O[sub 3], Cu/MnO/Cr[sub 2]O[sub 3] and Cu/ZnO/Al[sub 2]O[sub 3]. Of these three catalysts, the Cu/ZnO/Al[sub 2]O[sub 3] exhibits the greatest stability when slurried in octacosane. More than 1000 hours-on-stream indicate that the catalyst activity is not detrimentally affected by high pressure, high H[sub 2]/CO ratio, or the presence of alkenes. All of these are necessary stability characteristics for the water-gas shift catalyst, if it is to be used in combination with a cobalt Fischer-Tropsch catalyst. A review of documented reduction procedures for cobalt-based Fischer-Tropsch catalysts is presented.

  3. Novel Fischer-Tropsch slurry catalysts and process concepts for selective transportation fuel production: Quarterly technical progress report for the period 1 April-30 June 1986

    SciTech Connect

    Carroll, W.E.; Eliezer, K.F.; Mitchell, J.W.; Withers, H.P. Jr.

    1987-02-01

    In the seventh, and final quarter, work continued on the three major tasks: Task 2 - Development of Improved Supported Catalyst Compositions, Task 3 - Slurry Reactor Kinetic Studies, and Task 4 - Fuel Product Characterization. To examine the importance of surface area effects on the activity enhancement of the Co/Zr/silica catalyst, a Co/Zr/silica catalyst having the same surface area as the Co/Zr/alumina catalyst was tested in the fixed bed reactor. Silica provided an inherently more active catalyst than alumina but some of the enhancement that was initially observed was due to the increased surface area. The effect of increasing metal loadings on the performance of the Co/Zr/silica catalyst was examined with tests of 11% and 14.4$ Co catalysts in the fixed bed reactor. The 11% Co catalyst gave the highest syngas conversion (52%) at 220/sup 0/C of any catalyst tested at this temperature during this contract. Selectivity to liquid fuel product declined with increasing Co loading with an overall flattening of the hydrocarbon distribution. Slurry screening tests were performed on two catalysts. One was a cobalt on silica catalyst without any added promoter atoms such as Zr or Ti. The other screening test was a Zr promoted cobalt on silica catalyst with a high loading of Co. The extended slurry test which was begun in December 1985 was completed in June. During this quarter, a series of experiments was run to try to determine reaction kinetics. The spent catalyst from the extended slurry test of the Co/Zr/SiO/sub 2/ catalyst was found to contain 43.2% carbon and 2.4% hydrogen. This indicated a significant amount of coke formation. A second sample of liquid organic product was collected from the extended slurry test for testing as a diesel fuel. This sample met all the requirements for the highest quality diesel fuel except for viscosity and cloud point. 6 refs., 57 figs., 98 tabs.

  4. Effect of potassium promoter on cobalt nano-catalysts for fischer-tropsch reaction

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

    In the present work effect of potassium on cobalt nano-catalysts for Fischer-Tropsch reaction has been presented. The catalysts were prepared using a wet impregnation method and promoted with potassium. Samples were characterized by nitrogen adsorption, H2-TPR, and TEM. The Fischer-Tropsch Synthesis (FTS) was carried out in a fixed-bed microreactor 220 δC, 1 atm, H2/CO = 2 and a velocity (SV) =12 L/g.h. for 5 h. Addition of potassium into Co/CNTs decreased the average size of cobalt nanoparticles and the catalyst reducibility. Potassium-promoted Co catalyst resulted in appreciable increase in the selectivity of C5+ hydrocarbons and suppressed methane formation. The 0.06%KCo/CNTs catalyst enhanced the C5+ hydrocarbons selectivity by a factor of 23.5% and reduced the methane selectivity by a factor of 39.6%

  5. 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.

  6. Catalyst and reactor development for a liquid phase Fischer-Tropsch process. Quarterly technical progress report, 1 April-30 June 1984

    SciTech Connect

    Carroll, W.E.; Cilen, N.; Motika, S.A.

    1985-03-01

    In the fifteenth quarter work continued for two major tasks: (1) Slurry Catalyst Development, and (2) Catalyst A Development. For task one, parametric gas phase screening tests were concluded on a ''modified'' conventional catalyst and an optimum preparation and activation procedure chosen for diesel fuel selectivity. A short term slurry test of this catalyst showed promising results. Further work in modifying the composition of this catalyst may be worthwhile. Two tests were conducted on Catalyst A this quarter: (1) A test to determine the effect of air calcination pretreatment. At the same process conditions, the bulk activity was nearly three times that of the uncalcined batch of this catalyst. The diesel fuel fraction, however, was considerably lower. (2) A retest of a modified version of this catalyst, A'. The results of this test indicte that: the selectivity of A' is highly dependent on the CO/H/sub 2/ ratio; temperature affects both the activity and product selectivity (a 15% increase in bulk activity and a shifting of products into the lower molecular weight region resulted from an increase in temperature from 240 to 260/sup 0/C); and reproducibility of lower temprature results are not possible after extended testing at a higher temperature level indication that the performance of the catalyst is dependent on its history of operating conditions. A number of gas phase activation procedures were tested on Catalyst A'. No appreciable difference in activity and selectivity was observed. A test of air calcination pretreatment before gas phase activation, however, resulted in an appreciable increase in bulk activity and increase in the yield of gasoline fuel.

  7. X-ray nanoscopy of cobalt Fischer-Tropsch catalysts at work.

    PubMed

    Cats, Korneel H; Gonzalez-Jimenez, Ines D; Liu, Yijin; Nelson, Johanna; van Campen, Douglas; Meirer, Florian; van der Eerden, Ad M J; de Groot, Frank M F; Andrews, Joy C; Weckhuysen, Bert M

    2013-05-21

    Transmission X-ray microscopy has been used to investigate individual Co/TiO2 Fischer-Tropsch (FT) catalyst particles in 2-D and 3-D with 30 nm spatial resolution. Tomographic elemental mapping showed that Co is heterogeneously concentrated in the centre of the catalyst particles. In addition, it was found that Co is mostly metallic during FT at 250 °C and 10 bar. No evidence for Co oxidation was found. PMID:23586073

  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. Catalyst and reactor development for a liquid phase Fischer-Tropsch process. Quarterly technical progress report, 1 October 1983-31 December 1983

    SciTech Connect

    Brian, B.W.; Carroll, W.E.; Cilen, N.; Pierantozzi, R.; Nordquist, A.F.

    1985-01-01

    Two major tasks continued in the thirteenth quarter: (1) Slurry Catalyst Development; and (2) Slurry Reactor Design Studies. In addition, work, as part of a three month contract modification, was begun to develop and improve the activity and center the selectivity for diesel fuel products of a proprietary catalyst A. This catalyst was found to produce yields in the diesel fuel region equal to or greater than the Schulz-Flory maximum with low rates of deactivation and good stability during previous extended periods of testing. A phase two extended slurry test of a proprietary catalyst B was completed this quarter. A considerable improvement in activity was observed, making this batch nearly four times as active as in the first phase of testing. The selectivity for total, gasoline and diesel, fuels was over 65 wt % in both phases of testing. The results of this test show the importance of metals loading and the need for further development work to optimize the activity and selectivity for diesel fuel of this catalyst. A short term (21 day) slurry test was conducted on another modified catalyst optimized by the gas phase screening program. Parametric gas phase screening tests were conducted on three additional catalysts. The optimum preparation and activation methods for diesel fuel selectivity will be chosen as these tests are completed. In the hydrodynamic studies, work in the 12 inch Cold-Flow Simulator was completed. A Box-Behnken experimental design was utilized to determine the statistical significance of the independent parameters studied (superficial gas velocity, solids weight fraction, solid size, etc.) on gas holdup, as well as, any synergistic effects. Correlations for gas holdup in the 12 inch and 5 inch columns were obtained. In each column, a strong linear dependence on superficial gas velocity was obtained. 6 references, 5 figures, 5 tables.

  10. 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. PMID:24339240

  11. New ultrasonically prepared Co-based catalysts for Fischer-Tropsch synthesis.

    PubMed

    Bianchi, C L; Martini, F; Ragaini, V

    2001-04-01

    An extensive study of different preparation methods for Co/SiO2 catalysts is reported in this paper. In addition to the conventional impregnation, other more innovative methods are used including ultrasound. The prepared samples are fully characterized and tested in the CO hydrogenation (Fischer-Tropsch synthesis). The best catalytic performance, both as CO conversion and hydrocarbons selectivity, is shown by one of the sample prepared using ultrasound. PMID:11326608

  12. Novel Fischer-Tropsch slurry catalysts and process concepts for selective transportation fuel production. Quarterly technical progress report, 1 April-30 June 1985

    SciTech Connect

    Carroll, W.E.; Cilen, N.; Motika, S.A.; Withers, H.P. Jr.

    1986-07-01

    In the third quarter work continued on the two major tasks: Task 2 - Development of Improved Supported Catalyst Compositions; and Task 3 - Slurry Reactor Kinetic Studies. Within Task 2, work was accomplished in studying the effect of catalyst activation procedure on activity and selectivity of the basecase Co/sub 2/(CO)/sub 8/j/Zr(OPr)/sub 4//Al/sub 2/O/sub 3/ composition. Activation with pure H/sub 2/ gave a >100% increase in both bulk and specific activity in gas phase tests at 220/sup 0/C compared to the standard syngas activation. However, the activity enhancement was somewhat less at higher run temperatures. To establish a reference for the cobalt carbonyl-based catalysts, a catalyst was prepared and gas phase tested in which cobalt nitrate was used as the cobalt source and supported on zirconated alumina. Syngas and pure H/sub 2/ activation were also compared for this catalyst. A Co/sub 2/(CO)/sub 8//Zr(OPr)/sub 4//Al/sub 2/O/sub 3/ catalyst with increased cobalt loading was prepared to examine the effect of metal loading on catalyst performance. Initial analysis of these catalysts has been carried out using x-ray photoelectron spectroscopy (XPS) and H/sub 2/ chemisorption. Four catalysts were screened in the slurry phase reactors. These included the titanium promoted Co/sub 2/(CO)/sub 8/ on alumina catalyst, the Co/sub 2/(CO)/sub 8//Zr(OPr)/sub 4/ on alumina composition having a higher Co/Zr weight ratio of 1.15, and the potassium promoted mixed-metal composition of FeCo/sub 3/(CO)/sub 12/ on alumina. The fourth slurry screening test was done to examine the effect of pure H/sub 2/ activation on the performance of the basecase Co/sub 2/(CO)/sub 8//Zr(OPr)/sub 4/ on alumina catalyst. 63 figs., 131 tabs.

  13. Development of Precipitated Iron Fischer-Tropsch Catalysts

    SciTech Connect

    Burkur, D.B.; Ding, Y.; Chokkaram, S.

    1997-04-30

    Four (alumina or silica) supported catalysts were prepared by conventional impregnation of two commercial supports (silica - Davison grade 952; and alumina - Vista B). Nominal compositions (on mass basis) of synthesized catalysts are: (1) 100 Fe/5 Cu/6 K/139 SiO{sub 2} (2) 100 Fe/10 Cu/6 K/134 SiO{sub 2}, (3) 100 Fe/5 Cu/6 K/139 Al{sub 2}0{sub 3} and (4) 100 Fe/10 Cu/6 K/134 Al{sub 2}0{sub 3}. The corresponding weight % of iron (as metal) in the prepared catalysts is about 33.8%. Reduction behavior of the four supported catalysts was studied by both temperature programmed and isothermal reduction in hydrogen, and by isothermal reduction in CO at 280{degrees}C. Also, two precipitated promoted iron catalysts containing aluminum oxide as a binder, were reduced isothermally in the TGA unit with hydrogen at 240{degrees}C and 280{degrees}C. One of the two alumina containing catalysts (100 Fe/5 Cu/4.2 K/20 Al{sub 2}0{sub 3}) was tested in a slurry reactor (run SA-0097), and catalyst samples withdrawn from the reactor at various times on stream were characterized by XRD to determine bulk iron phases in the catalyst. Two slurry reactor tests were completed during this quarter. The first test (SA-0097) was conducted with alumina containing catalyst with nominal composition 100 Fe/5 Cu/4.2 K/20 Al{sub 2}0{sub 3}, which was synthesized previously in our laboratory (DOE Contract DE-AC22-85PC8001 1). The second test (SB-0627) was conducted with one of the silica supported catalysts which was prepared during this quarter: 100 Fe/5 Cu/6 K/139 SiO{sub 2} (Davison silica, grade 952). The performance of these two catalysts was inferior in comparison to our catalysts B (100 Fe/5 Cu/6 K/24 SiO{sub 2}) and C (100 Fe/3 Cu/4 K/16 SiO{sub 2}). Activity of these two catalysts was lower, catalyst deactivation rate was faster, and gaseous hydrocarbon selectivities were higher in comparison to the baseline catalysts B and C.

  14. Catalyst and reactor development for a liquid-phase Fischer-Tropsch process. Quarterly technical progress report, 1 October 1982-31 December 1982

    SciTech Connect

    Dyer, P.N.; Pierantozzi, R.; Brian, B.W.; Bauer, J.V.; Parsons, R.L.

    1983-03-01

    Two major tasks were continued: (1) Slurry Catalyst Development, and (2) Slurry Reactor Design Studies. The first extended slurry test was begun, using a proprietary catalyst. High selectivities and large deviations from the Schulz-Flory distribution were observed. A bulk activity 2.5 times greater than the baseline Fe/sub 2/O/sub 3/ was determined, with little deactivation over 450 h. Consistently low CH/sub 4/ yields of 3 to 5 wt %, and high C/sub 9/-C/sub 25/ fractions of 45 to 50 wt %, were produced at 240/sup 0/C, 300 psig and 1:1 CO/H/sub 2/. This test is being continued with higher CO/H/sub 2/ ratios and operating temperatures. Parametric gas phase screening studies were concluded for two further modified conventional catalysts and the optimum preparations in terms of activity and diesel range selectivity were chosen for subsequent slurry phase testing. Gas holdup and solid concentration profiles were measured for water/silica slurries in the 5'' column, and for paraffin/silica slurries in the 12'' column, both with and without heat transfer internals. In both columns, gas holdup was found to be close to the Akita and Yoshida correlation. Very non-uniform solid concentration profiles were observed in the 2 column for the 90 to 115 ..mu..m size silica, with settling of the slurry on the distributor plate. Smaller size particles were more uniformly distributed. Heat transfer coefficients were determined in the 12'' column for paraffin/silica slurries, using seven vertical, tubular heat transfer elements. The values were in good agrement with Deckwer's correlation for the large and medium size particles, but were lower for the 0.5 to 5 ..mu..m size range. The bubble size diameter probe was successfully calibrated using a strobe technique, and data acquisition will begin next quarter.

  15. Fischer-Tropsch slurry phase process variations. Quarterly report, April 1-June 30, 1986

    SciTech Connect

    Satterfield, C.N.; Hanlon, R.; Matsumoto, D.K.

    1986-01-01

    In studies at 232/sup 0/C and 248/sup 0/C and 0.92 MPa, during the first 20 hours on stream, both Fischer-Tropsch synthesis activity and CO consumption increased to quasi-steady-state values. The bulk catalyst, initially ..cap alpha..-Fe, was converted to a mixture of ..cap alpha..-Fe and iron carbides, as determined by Moessbauer spectroscopy. During the first few hours, methane selectivity decreased markedly while the olefin/paraffin ratio increased. No change was observed in the C/sub 2/-C/sub 8/ product distribution with time on stream. When an industrial iron-based Fischer-Tropsch catalyst is first put on stream some 20 to 40 hours may elapse before its activity and selectivity approach steady-state conditions and during this time the phases present in the catalyst usually change markedly. The present study used a fused triply-promoted magnetite catalyst, sold for use in ammonia synthesis, which is very similar to one of the kinds of iron catalyst used industrially at SASOL in South Africa. It was completely reduced initially. Reaction was carried out in semi-continuous fashion in a well-stirred 1-litter autoclave. We were particularly concerned with studying the activity and selectivity of this catalyst as it approached steady-state behavior and determining if this correlated with the phases present in the catalyst as determined by Moessbauer spectroscopy. 20 refs., 9 figs., 1 tab.

  16. 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.

  17. Reaction engineering of slurry phase Fischer-Tropsch synthesis with porous cobalt catalysts

    SciTech Connect

    Han, Y.H.; Li, F.; Fujimoto, Kaoru

    1997-12-31

    Fischer-Tropsch synthesis was conducted in the slurry phase using a stirred reactor and supported cobalt catalysts. Under well stirred conditions, neither the mass transfer between the gas-solid interface nor the liquid-solid interface was found to be the rate limiting step in the reaction sequence. The catalytic activity and product selectivity were markedly affected by the particle size for small pore (20 angstroms) catalyst while those of a large pore catalyst were not affected by the particle where the partial diameter is larger than 0.1 mm. The phenomena were well simulated by theoretical calculations.

  18. 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.

  19. Development and process evaluation of improved Fischer-Tropsch slurry catalysts: Quarterly technical progress report for the period 1 April to 30 June 1987

    SciTech Connect

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

    1987-08-25

    Three runs were made with a commercial fused iron catalyst with objectives to study the effects of catalyst reduction procedure, particle size and process conditions on fixed bed reactor performance (activity and product selectivity). The catalyst activity increases as the space velocity of H/sub 2/ during the reduction increases or as the catalyst particle size decreases. An uncalcined precipitated iron catalyst (100 Fe/1 Cu/0.2 K on weight basis) was evaluated in a fixed bed reactor. Initially, it showed an activity more than twice of the fused iron catalyst, but it deactivated after about 30 hours on stream. The work on catalyst synthesis and characterization of the precipitated iron catalysts has continued. 25 precipitated iron catalysts (Fe/Cu, Fe/K and Fe/Cu/K) have been prepared. Temperature programmed reduction has revealed that the iron reduction is facilitated in the presence of copper. Also, unpromoted iron and potassium promoted iron (containing 1 part K per 100 parts Fe) were examined using Fourier Transform Infrared Spectroscopy. 9 refs., 19 figs., 8 tabs.

  20. Development and process evaluation of improved Fischer-Tropsch slurry catalysts: Quarterly technical progress report for the period 17 October 1986 to 31 January 1987

    SciTech Connect

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

    1987-03-23

    A literature search of precipitated iron/copper/potassium catalyst has been completed. A catalyst precipitation unit has been assembled and tested. A pure precipitated iron catalyst has been synthesized and its BET surface area and temperature-programmed reduction (TPR) behavior have been determined. All equipment supplied by APCI has been made operational. The design of two new reactor systems (slurry and fixed bed) has been completed, and some of the equipment and parts necessary for their construction have arrived. Progress has been made in the areas of chromatograph calibrations and data reduction software. 24 refs., 6 figs., 8 tabs.

  1. 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.

  2. Catalyst and reactor development for a liquid phase Fischer-Tropsch process. Quarterly technical progress report, 1 July 1983-30 September 1983

    SciTech Connect

    Brian, B.W.; Carroll, W.E.; Cilen, N.; Pierantozzi, R.; Nordquist, A.F.

    1984-11-01

    Two major tasks of the contract continued: (1) slurry catalyst development, and (2) slurry reactor design studies. The second extended slurry test, using a proprietary catalyst was completed. The results were not consistent with a previous short term test of this catalyst where high activity and yields in the diesel fuel region equal to or greater than the Schulz-Flory maximum were observed. The increased methane production and lower bulk activity over the previous test may have been the result of a variation in the surface active species of this catalyst. A short term (21 day) slurry test was carried out on another modified conventional catalyst. Parametric gas phase screening results were concluded for four additional catalysts, and the optimum preparation and activation methods for diesel fuel selectivity were chosen. In the hydrodynamic studies, work in the 12 inch Cold Flow Simulator continued. The following observations and/or conclusions were obtained: superficial gas velocity is the major factor for determining gas holdup; the major determining factor of the solids concentration profile in a slurry bed is particle size; heat transfer coefficients for the two-phase isoparaffin/N/sub 2/ were 64% of that predicted by Deckwer's correlation and for the three-phase Fe/sub 2/O/sub 3//isoparaffin, the results were better at 71%; bubble diameter measurements were obtained using a double hot film probe; the Air Products gas holdup correlation was incorporated into Deckwer's model of the three phase bubble column. A simulation utilizing kinetic data from an Air Products diesel fuel selective catalyst, under Rheinpreussen conditions, resulted in doubling the space time yield of the Rheinpreussen base case catalyst. 9 references, 12 figures, 8 tables.

  3. Catalyst and reactor development for a liquid phase Fischer-Tropsch process. Quarterly technical progress report, 1 April-30 June 1983

    SciTech Connect

    Brian, B W; Carroll, W E; Cilen, N; Pierantozzi, R; Nordquist, A F

    1984-10-01

    Two major tasks of the contract continued: (1) Slurry Catalyst Development, and (2) Slurry Reactor Design Studies. A third phase of the extended slurry test of the proprietary catalyst was conducted using a new catalyst batch to confirm that the change in selectivity and loss of activity, observed in the second phase, was due to air exposure of the catalyst. The results were in line with the high diesel fuel production as before the suspected oxidation. Excess CO exposure during this last phase of testing resulted in a reduction in catalyst activity and a shift in selectivity to heavier hydrocarbons with a Schulz-Flory maximum centered around C/sub 30/. The variations in selectivity and activity upon oxidation through air exposure, or surface carbon deposition through excess CO exposure, have confirmed the importance of understanding the mechanism for product selectivity. Further development with the aid of surface analysis techniques is required to control and center the selectivity for the diesel fuel range. Short term slurry tests were carried out on three catalysts, the preparation and activation procedures of which were optimized by the gas phase screening program. In the hydrodynamic studies, correlations were derived for the 5'' column data. In the 12'' column, fitted with 7 vertical heat transfer tubes, hydrodynamic parameters were determined for slurries of 45 to 90 ..mu..m Fe/sub 2/O/sub 3/ in paraffin and water. A double, conical, hot film probe to measure bubble diameter was successfully operated in a three phase slurry. Using Deckwer's model of the three phase bubble column, and kinetic data derived from the lab CSTR tests, the performance of Air Products' selective catalysts in a 1.5 x 8 m column (i.e., the size of Rheinpruessen) was simulated under both quiescent and churn turbulent conditions. 7 references, 8 figures, 6 tables.

  4. Catalyst and reactor development for a liquid-phase Fischer-Tropsch process. Quarterly technical progress report, 1 April 1982-30 June 1982

    SciTech Connect

    Dyer, P.N.; Pierantozzi, R.; Brian, B.W.; Bauer, J.V.

    1982-08-01

    Two major current tasks are: Slurry Catalyst Development, and Slurry Reactor Design Studies. Seven supported conventional catalysts, prepared with different metal precursors, concentrations, calcination procedures and supports, were tested in the gas phase to determine the effect of these parameters on activity and selectivity. A second slurry test of the baseline catalyst, sintered Fe/sub 2/O/sub 3/, utilized CO rich syngas to determine reactor mass transfer limitations. The product from 1.4:1 CO/H/sub 2/ approximated a straight line Schulz-Flory distribution, but higher CO/H/sub 2/ ratios gave increased high molecular weight material. Methane yields were low and high water gas shift activity gave a close match between syngas feed and usage ratios. At T > 250/sup 0/C some mass transfer effects were observed, and are being incorporated into a reactor model. Six additional slurry tests used supported molecular cluster catalysts. Initially in this series, slurry phase activities were low. A slurry test of one supported cluster showed marked deviations from the standard Schulz-Flory distribution in the C/sub 10/-C/sub 29/ region, but at very low conversion. Subsequent supported cluster catalyst tests led to a method of obtaining high slurry phase activities equal to the gas phase. A slurry test of another cluster catalyst utilizing this method gave high activity, but did not reproduce the product selectivity for C/sub 10/-C/sub 18/ observed in its previous gas phase test. At higher pressure, 750 psig, and 280/sup 0/C, however, methane yields decreased, becoming independent of the CO/H/sub 2/ ratio, and the Schulz-Flory product distribution became nonlinear with a definite cutoff at approx. C/sub 28/. Two supported cluster catalysts were prepared and seven were screened in the gas phase.

  5. Synthesis and catalytic properties of eggshell cobalt catalysts for the Fischer-Tropsch synthesis

    SciTech Connect

    Iglesia, E.; Soled, S.L.; Baumgartner, J.E.

    1995-04-15

    CO diffusional restrictions decrease the rate and C{sup +}{sub 5} selectivity in large (1-3 mm) catalyst pellets required for Fischer-Tropsch synthesis in packed bed reactors. Eggshell catalysts, in which the active Co component is preferentially located near the outer pellet surface, decrease these transport restrictions and increase Fischer-Tropsch synthesis rates and C{sup +}{sub 5} selectivity. Maximum C{sup +}{sub 5} selectivities occur on catalysts with intermediate shell thickness, because these catalysts avoid intrapellet CO concentration gradients but still restrict the diffusive removal of reactive olefin products, which can readsorb and continue to grow to higher molecular weight hydrocarbons. Eggshell catalysts were prepared by a novel impregnation technique using molten cobalt nitrate. The eggshell thickness is controlled by the melt viscosity and by the contact time between the melt and the support pellet. These impregnation procedures and the slow reduction of the impregnated nitrate salts lead to relatively high cobalt dispersions (0.05-0.07) even at the high Co concentrations (40-50 wt%) present within the shell region. 51 refs., 8 figs., 4 tabs.

  6. Cobalt cluster effects in zirconium promoted Co/SiO{sub 2} Fischer-Tropsch catalysts

    SciTech Connect

    Feller, A.; Claeys, M.; Steen, E. van

    1999-07-01

    The effect of zirconium addition to the catalyst formulation of Co/SiO{sub 2} Fischer-Tropsch catalysts was investigated. With increasing zirconium content the strong interaction between silica and cobalt is reduced and a somewhat weaker cobalt-zirconium interaction is observed. Therefore the degree of reduction of catalysts, which were reduced at 400 C for 16 h, increases strongly. The cobalt crystallite size increases with increasing zirconium content, leading to smaller cobalt metal surface areas for the freshly reduced catalyst. Cobalt particles can be found in clusters on the silica support. The size of cobalt clusters decreases and thus the number of cobalt particles within a cluster decreases with increasing zirconium content. At steady-state conditions the CO-conversion of the promoted catalyst in the Fischer-Tropsch synthesis increases with increasing zirconium content. The C{sub 5+}-selectivity and the secondary hydrogenation activity pass a maximum with increasing zirconium content. The observed changes in activity and selectivity are explained in terms of an increase in the amount of metallic cobalt available under reaction conditions, leading to an increased activity, and a decrease in the cobalt cluster size, which diminishes the probability for secondary reactions. Furthermore, it was concluded that secondary double bond isomerization can be catalyzed to some extent by zirconia.

  7. Catalyst and reactor development for a liquid-phase Fischer-Tropsch process. Quarterly technical progress report, 1 October 1981-31 December 1981

    SciTech Connect

    Dyer, P.N.; Pierantozzi, R.; Brian, B.W.; Bauer, J.V.

    1982-01-01

    This program contains four major tasks: (1) Project Work Plan, (2) Slurry Catalyst Development, (3) Slurry Reactor Design Studies, and (4) Pilot Facility Design. In Task 2, five modified conventional catalysts were prepared, and six gas phase screening tests were carried out. One of these catalysts gave an excellent diesel fuel type product distribution, with a low CH/sub 4/ yield and good stability. Two slurry tests were run. The first used a 19 wt % slurry of ammonia synthesare catalyst as a baseline F-T case, and incorporated the slurry reactor mass transfer tests by varying stirring rates and space velocities as a function of temperature. Product distributions were straight line Schulz-Flory, as expected with this type of catalyst. The data are currently being analyzed to separate mass transfer and chemical rate effects. The second utilized a slurry of a coprecipitated catalyst, activated in the slurry phase. The pressure and temperature required for activation and reaction were found to be higher than for the gas phase screening tests, and deviations from the standard hydrocarbon product distribution were small. The usage and feed ratios were equal for 1:1 syngas. Seven supported cluster catalysts were synthesized and eight were screened in the gas phase. One of these produced a high selectivity to 1-butene and n-pentane. In Task 3, measurements of gas hold-up and solids dispersion in the 5'' column were completed for the 45 to 53 ..mu..m and 90 to 106 ..mu..m iron oxide/isoparaffin systems. Contrary to the silica slurry results, an increase in gas hold-up was observed with a positive slurry velocity. No dependence of gas hold-up on distributor type was observed, however. With the 43 to 53 ..mu..m slurry, the solids concentration profiles were uniform under all conditions studied, but with the 90 to 106 ..mu..m slurry, a decrease in solids concentration with column height was observed at zero slurry velocity.

  8. 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%). PMID:20359031

  9. Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst. [Quarterly] report, April 1, 1990--June 30, 1990

    SciTech Connect

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

    1990-12-31

    Experiments on cobalt-catalyzed reactions of light 1-alkenes added to synthesis gas were performed. Data have been collected at 220C, 0.45 to 1.48 MPa and a synthesis gas flow rate between 0.015 and 0.030 Nl/(gcat{center_dot}min) with H{sub 2}/CO of 1.45 to 2.25. Ethylene, propene, and butene were added to synthesis gas feed from 0.5 to 1.2 mole% of total feed. For each material balance in which 1-alkenes were added, a material balance was performed at similar process conditions without 1-alkenes added, as ``base case``. Material balances without added 1-alkenes were also repeated to verify of catalyst selectivity stability. 49 material balances were performed during a single run lasting over 2,500 hours-on-stream. The hydrocarbon data have been completely analyzed; data correlations are still being made. Since C{sub 3}/C{sub 1} ratios by ethene addition, C{sub 4}/C{sub 1} ratios by propene addition, and C{sub 5}/C{sub 1} ratios by 1-butene addition, it appears that 1-alkenes may incorporate into growing chains on the surface of the catalyst. Further evidence for incorporation can be seen by comparing selectivity to n-alcohol one carbon number higher than added 1-alkene. Yield of this n-alcohol increases when alkenes are present. Sensitivity of hydrocarbon distribution to process variables seems to be greater on Co than on Fe catalysts.

  10. Iron and cobalt Fischer-Tropsch catalysts prepared by the solvated metal-atom technique

    SciTech Connect

    Meier, P.F.; Pennella, F.; Klabunde, K.J.; Imizu, Y.

    1986-10-01

    It is reasonable that at low metal loadings a more active catalyst would result from deposition on a support of a metal in the reduced, metallic state. Deposition of less than 5 wt% cobalt on alumina in the form of cobalt carbonyl produced catalysts of good activity. The Solvated Metal Atom Deposition Technique (SMAD) provides a method of catalyst preparation for which the deposition of metallic catalysts on a support has been demonstrated. This note reports a comparative study of the Fischer-Tropsch synthesis activity of iron and cobalt catalysts prepared by this technique and supported on silica with less than 5 wt% of the metal, and of analogous catalysts prepared by conventional impregnation techniques. 16 references.

  11. Catalyst and reactor development for a liquid phase Fischer-Tropsch process

    SciTech Connect

    Not Available

    1989-01-01

    The preparation, characterization, and performance of a range of metal catalysts for use in slurry phase Fischer-Tropsch technology was investigated with the objective of developing new compositions with improved selectivity for gasoline and diesel fuel range hydrocarbons. A series of conventional catalysts was identified for testing for both gas and slurry phases. A gas phase screening protocol was set up to allow reasonably rapid determination of each catalyst's synthesis gas conversion characteristic over a range of operating conditions. The catalysts selected represented a range of catalytic metals known to promote conversion of synthesis gas to hydrocarbon liquids. Both precipitates and supported variations of these metals were studied. Catalysts studied include: ruthenium-based catalysts with osmium, and cobalt carbonyl supported on zirconia promoted. 23 refs., 2 figs., 10 tabs.

  12. Nitrided iron catalysts for the Fischer-Tropsch synthesis in the eighties

    SciTech Connect

    Anderson, R.B.

    1980-01-01

    A survey covers the preparation and structure of nitrided iron catalysts and their activity, selectivity, and stability for the reaction of synthesis gas in comparison with iron catalysts pretreated by various other methods, as measured in laboratory reactors; a comparison of product distributions obtained in fluidized-bed, slurry, and oil-circulation fixed bed pilot plants with nitrided catalysts and by the Kellogg entrained catalyst process SASOL, which uses a reduced iron catalyst; and possible methods for refining the Fischer-Tropsch products from nitrided iron catalysts for producing gasoline, including bauxite treatment, the Mobil process for converting oxygenates to high-octane gasoline and C/sub 3/-C/sub 4/ olefins, and an alkylation-polymerization process for converting the C/sub 3/-C/sub 4/ fraction to high-octane blending stocks.

  13. Nanoscale attrition during activation of precipitated iron Fischer-Tropsch catalysts: Implications for catalyst design

    SciTech Connect

    Datye, A.K.; Shroff, M.D.; Jin, Y.; Brooks, R.P.; Wilder, J.A.

    1996-12-31

    The Fischer-Tropsch Synthesis (FTS) for the production of liquid hydrocarbons from coal-based synthesis gas has been the subject of renewed interest for conversion of coal to liquid fuels. The use of synthesis gas from modem energy-efficient gasifiers requires catalysts that can operate under low H{sub 2}/CO ratios, typically 0.7-0.9. Since the FTS stoichiometry requires a H{sub 2}/CO ratio of 2.0, catalysts that operate at lower ratios must catalyze the water gas shift reaction to make up the deficit in H{sub 2}. The use of iron-based catalysts for the process is attractive in view of their low cost, ready availability and high water-gas shift reactivity. Furthermore, iron catalysts at elevated pressures (10-15 atmospheres) produce the desired range of liquid hydrocarbons. AU these features make the use of Fe as an F-T catalyst extremely desirable. Since the reaction is highly exothermic, the preferred reactor type for industrial operation is the slurry bubble column reactor. The catalyst for this reactor is precipitated iron oxide which is spray dried to yield particles with diameter of 30-70 {mu}m. One major limitation of these catalysts is that they tend to undergo attrition during use, leading to problems in catalyst separation and recovery of liquid products from the reactor.

  14. Low nitrogen iron-containing Fischer-Tropsch catalyst for conversion of synthesis gas and process for preparing the catalyst

    SciTech Connect

    Bell, W.K.; Haag, W.O.; Kirker, G.W.; Klocke, D.J.

    1986-10-14

    A process is described for preparing an iron-containing Fischer-Tropsch catalyst by continuously precipitating an aqueous solution containing iron nitrate with aqueous ammonia, to form a precipitate-containing product which is thereafter dried. In the improvement described here a catalyst containing less than 500 ppm nitrogen is produced which comprises maintaining a pH of about 6.5 to 6.9 and a temperature of about 70/sup 0/ to 100/sup 0/ C. during precipitation.

  15. 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.

  16. 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.

  17. 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.

  18. Development of attrition resistant iron-based Fischer-Tropsch catalysts

    SciTech Connect

    2000-09-20

    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-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 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 a steady loss of catalyst from the reactor. The objective of this research is to develop robust iron-based Fischer-Tropsch catalysts that have suitable activity, selectivity and stability to be used in the slurry bubble column reactor. Specifically we aim to develop to: (1) improve the performance and preparation procedure of the high activity, high attrition resistant, high alpha iron-based catalysts synthesized at Hampton University (2) seek improvements in the catalyst performance through variations in process conditions, pretreatment procedures and/or modifications in catalyst preparation steps and (3) investigate the performance in a slurry reactor. The effort during the reporting period has been devoted to effects of pretreating procedures, using H{sub 2}, CO and syngas (H{sub 2}/CO = 0.67) as reductants, on the performance (activity, selectivity and stability with time) of a precipitated iron catalyst (100Fe/5Cu/4.2K/10SiO{sub 2} on a mass basis ) during F-T synthesis were studied in a fixed-bed reactor.

  19. 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%).

  20. 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.

  1. 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.

  2. 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.

  3. Development of improved iron Fischer-Tropsch catalysts

    SciTech Connect

    Bukur, D.B.; Patel, S.A.

    1990-01-15

    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.

  4. Development of improved iron Fischer-Tropsch catalysts

    SciTech Connect

    Bukur, D.B.

    1991-10-28

    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.

  5. Development of improved iron Fischer-Tropsch catalysts

    SciTech Connect

    Bukur, D.B.

    1990-10-29

    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.

  6. Development of improved iron Fischer-Tropsch catalysts

    SciTech Connect

    Bukur, D.B.

    1991-07-19

    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.

  7. Development of improved iron Fischer-Tropsch catalysts

    SciTech Connect

    Bukur, D.B.

    1991-04-24

    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.

  8. Development of improved iron Fischer-Tropsch catalysts

    SciTech Connect

    Bukur, D.B.

    1991-01-25

    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.

  9. 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.

  10. 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

    2014-01-01

    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. PMID:25503569

  11. ɛ-Iron carbide as a low-temperature Fischer-Tropsch synthesis catalyst

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    ɛ-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 ɛ-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 ɛ-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.

  12. Role of copper promotion in precipitated iron Fischer-Tropsch catalysts

    SciTech Connect

    O`Brien, R.J.; Xu, L.; Davis, B.H.

    1996-10-01

    Slurry phase Fischer-Tropsch synthesis was conducted on precipitated iron-silicon catalysts. The affect of copper promotion on the activity and selectivity of carbon monoxide, hydrogen and syngas activated catalysts is presented. High activity and stability have been obtained for potassium promoted catalysts when operating at 270{degrees}C; however, it has been found that promotion with potassium and copper is essential to obtaining good activity in a wax producing mode at 230{degrees}C. Promotion with copper is critical to achieving good activity when pretreating catalysts with hydrogen or with syngas at high pressure. XRD and Mossbauer data indicate that copper facilitates the reduction of iron oxide to metallic iron and iron carbides during hydrogen and syngas pretreatments.

  13. 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.

  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. 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

    2015-01-01

    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. PMID:25740709

  16. 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.

  17. Fischer-Tropsch reaction studies with supported ruthenium catalysts

    SciTech Connect

    Everson, R.C.; Mulder, H. )

    1993-09-01

    An investigation was undertaken to examine the production of low molecular weight alkenes (C[sub 2][sup =] to C[sup =][sub 4]) and high molecular weight hydrocarbons (C[sub 5]+) from synthesis gas in a fixed bed reactor with supported ruthenium catalyst. The catalyst used consisted of 0.5% ruthenium on gamma-alumina with a 43% metal dispersion. An experimental reactor consisting of a single 12.5-mm-diameter stainless-steel tube with catalyst packings up to 1 m long, surrounded by an aluminium block with heating elements and an outer insulating ceramic block was used. The effect of temperature, synthesis gas composition (CO/H[sub 2]), weight hourly space velocity (WHSV), and bed length on carbon monoxide conversion and selectivity was examined and results are reported. The presence of secondary reactions consisting of hydrogenation and chain growth involving alkenes along the reactor bed was observed. These reactions favour the formation of alkanes and high molecular weight hydrocarbons. The alkene to alkane ratio in the product can be increased by restricting the hydrogenation reaction with the use of a synthesis gas mixture with a high carbon monoxide to hydrogen ratio.

  18. Technology development for iron Fischer-Tropsch catalysis. Quarterly technical progress report, 1996

    SciTech Connect

    Davis, B.H.

    1996-11-01

    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 ``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 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, select and aging characteristics. The research is divided into four major topical areas: (a) catalyst preparation and characterization, (b) product characterization, (c) reactor operations, and (d) data assessment. Accomplishments for this period are described.

  19. Activation and promotion studies in a mixed slurry reactor with an iron-manganese Fischer-Tropsch catalyst

    SciTech Connect

    Pennline, H.W.; Zarochak, M.F.; Stencel, J.M.; Diehl, J.R.

    1987-03-01

    Synthesis gas was reacted over a coprecipitated iron-manganese Fischer-Tropsch catalyst in a slurry reactor. The effect of various activation parameters - temperature, pressure, and gas composition - on subsequent catalyst activity and product selectivity was investigated. The gas composition had the most dramatic effect on the catalyst activation and the ensuing synthesis gas conversion. The effect of potassium promotion on catalyst activity and product selectivity was also studied in slurry reactor tests.

  20. Titania-supported bimetallic catalysts combined with HZSM-5 for Fischer-Tropsch synthesis

    SciTech Connect

    Jothimurugesan, K.; Gangwal, S.K.

    1998-04-01

    The Fischer-Tropsch synthesis (FTS) can convert coal or natural gas derived synthesis gas (CO + H{sub 2}) to liquid fuels and high-value chemicals. Fischer-Tropsch synthesis was studied in a fixed-bed reactor over single-metal and bimetallic alloy catalysts, selected from Co, Ni, and Fe, supported on TiO{sub 2} at a total metal loading of 10 wt%. The catalysts, prepared by incipient wetness impregnation using nitrate precursors, were tested as is and in combination with a HZSM-5 zeolite. The test conditions were 1 MPa, 250 C, H{sub 2}/CO = 1, and weight hourly space velocity (WHSV) = 0.77 h{sup {minus}1}. Alloying of metals resulted in a significant enhancement in CO conversion without an increase in methane selectivity. A 50:50 weight ratio Co-Ni catalyst physically mixed with HZSM-5 (5% Co-5% Ni/TiO{sub 2} + HZSM-5) gave the highest CO conversion (45.2%) at the conditions tested. This compares to conversion of 8.9% and 10.5% with Co-only and Ni-only catalysts, respectively. Mixing the Co-Ni catalyst with HZSM-5 resulted in a significant reduction in methane selectivity and a significant increase in C{sub 4}{sup +} selectivity. The aromatic fraction increased from 1.5 to 8.1 wt%, the C{sub 2}{sup +} olefins were nearly eliminated, and i-C{sub 4}H{sub 10} increased from 2.3 to 58.5 wt % in the C{sub 4} fraction.

  1. Mössbauer study of CO-precipitated Fischer-Tropsch iron catalysts

    NASA Astrophysics Data System (ADS)

    Rao, K. R. P. M.; Huggins, Frank E.; Mahajan, Vikram; Huffman, Gerald P.; Bukur, D. B.; Rao, V. U. S.

    1994-12-01

    Mössbauer spectroscopy studies of precipitated Fischer-Tropsch (FT) iron catalysts, viz. 100 Fe/5 Cu/4.2 K/ x SiO2, where x=0,8, 16, 24, 25, 40, or 100, have shown that reduction of the oxide precursor in CO gives rise to χ-carbide Fe5C2 whose amount decreases with an increase of SiO2 content. The χ-carbide is converted into magnetite Fe3O4 while catalyzing the FT synthesis reaction. A correlation between FT activity and the content of χ-carbide in the catalysts was found, which indicated that χ-carbide is active for FT synthesis reaction.

  2. 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

    Experiments to study the cobalt-catalyzed and iron-catalyzed reactions of light 1-alkenes added to synthesis gas have been performed and analyzed. On cobalt, data have been obtained at 220{degrees}C, 0.45 to 1.48 MPA and a synthesis gas flow rate between 0.015 and 0.030 Nl/gcat/min with H{sub 2}/CO feeds of 1.45 to 2.25. On fused iron, data were collected at 248{degrees}C, 0.79 to 1.48 MPa and a synthesis gas flow rate between 0.005 and 0.030 Nl/gcat/min of H{sub 2}/CO feeds of 0.5 to 1.5 C{sub 2}H{sub 4}, C{sub 3}H{sub 6}, and 1-C{sub 4}H{sub 8} were added to the synthesis gas feed in concentrations ranging from 0.5 to 1.2 mol. % of total feed. 1-Alkenes incorporate into growing chains on the catalyst surface of both catalysts, probably by initiating and/or terminating the chain growth process. Only ethene is believed to propagate chain growth significantly. The propensity of the 1-alkenes to incorporate decreases with increasing carbon number of the 1-alkene. The double-{alpha} behavior which is exhibited by most Fischer-Tropsch catalysts can be explained as the sum of two growth processes, one stepwise single-carbon growth and the other 1-alkene incorporation. Both alkene addition study data and the effects of process variables on the selectivity of Fischer-Tropsch catalysts can be explained within the framework of this theory. 19 refs., 12 figs., 2 tabs.

  3. Nanoscale attrition during activation of precipitated iron Fischer- Tropsch catalysts: Implications for catalyst design

    SciTech Connect

    Datye, A.K.; Shroff, M.D.; Jin, Y.; Brooks, R.P.; Wilder, J.A.; Harrington, M.S.; Sault, A.G.; Jackson, N.B.

    1996-06-01

    This work has shown that the kaolin binder that has been used in commercial Fischer-Tropsch Synthesis catalysts doe not offer any significant attrition resistance. This is due in part to its morphology (plate-like) and to its particle size being much greater than the primary crystallite size of the iron oxide catalyst. From a microscopic examination of these catalysts, it appears that if the nanoscale attrition of the iron catalyst is to be avoided, the iron must be well dispersed on the binder, and the binder must provide an interlocking microstructure that provides strength and stability to the 30-70 {mu}m agglomerates. The study of Fe/SiO{sub 2} catalysts has shown that co-precipitation of the iron and silica leads to formation of an amorphous glassy phase which is difficult to reduce even at 723K. On the other hand, when the iron was precipitated on a preformed silica, 25-40% of the iron could be reduced and carbided. The supported iron catalyst, after reduction, formed 15-20 nm iron carbide particles that look very similar to those on the unsupported catalyst. The major difference is these nanometer sized particles are anchored on a support and therefore would not be expected to breakup further and contribute to the fines generated as catalyst attrition proceeds. However, since only a fraction of the silica-supported iron can be reduced to the active carbide phase, our present efforts are devoted to moderating the Fe/SiO{sub 2} interaction by introducing an interfacial oxide phase. We are also studying the role of added Cu on the ease of reducibility of Fe/SiO{sub 2}. The implication of this work is that other binder materials should be explored that have a morphology that can strengthen the agglomerates and minimize the Fe-SiO{sub 2} interfacial reactions. This work is presently underway in our laboratory.

  4. 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.

  5. 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.

  6. 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.

  7. Separation of Fischer-Tropsch catalyst/wax mixtures using dense gas extraction

    SciTech Connect

    Eyring, M.W.; Rohar, P.C.; Hickey, R.F.; White, C.M.; Quiring, M.S.

    1995-12-31

    The separation of a Fischer-Tropsch catalyst from wax products is an important issue when the synthesis is conducted in a slurry bubble column reactor. This paper describes a new technique based on dense gas extraction of the soluble hydrocarbon components from the insoluble catalyst particles using light hydrocarbons as propane, butane, and pentane an the solvent. The extractions were conducted in a continuous unit operated near the critical point of the extraction gas on a catalyst/wax mixture containing about 4.91 wt% catalyst. The catalyst-free wax was collected in the second stage collector while the catalyst and some insoluble wax components were collected in the first stage collector. The yield of catalyst-free wax was about 60 wt% of the food mixture. The catalyst content of the catalyst/wax mixture in the first stage was about 14.8 wt%. The catalyst content in the second stage collector was less than 1 part in 100,000.

  8. Separation of Fischer-Tropsch catalyst/wax mixtures using dense gas extraction

    SciTech Connect

    Eyring, M.W.; Rohar, P.C.; Hickey, R.F.

    1995-12-01

    The separation of a Fischer-Tropsch catalyst from wax products is an important issue when the synthesis is conducted in a slurry bubble column reactor. This paper describes a new technique based on dense gas extraction of the soluble hydrocarbon components from the insoluble catalyst particles using light hydrocarbons as propane, butane, and pentane as the solvent. The extractions were conducted in a continuous unit operated near the critical point of the extraction gas on a catalyst/wax mixture containing about 4.91 wt% catalyst. The catalyst-free wax was collected in the second stage collector while the catalyst and some insoluble wax components were collected in the first stage collector. The yield of catalyst-free wax was about 60 wt% of the feed mixture. The catalyst content of the catalyst/wax mixture in the first stage was about 14.8 wt%. The catalyst content in the second stage collector was less than 1 part in 100,000.

  9. Development of a stable cobalt-ruthenium Fischer-Tropsch catalyst

    SciTech Connect

    Abrevaya, H.

    1991-01-01

    The objective of this contract is to examine the relationship between catalytic properties and the function of cobalt Fischer-Tropsch catalysts and to apply this fundamental knowledge to the development of a stable cobalt-based catalyst with a low methane-plus-ethane selectivity for use in slurry reactors. An experimental cobalt catalyst 585R2723 was tested three times in the fixed-bed reactor. The objective of the tests was to identify suitable testing conditions for screening catalyst. The {alpha}-alumina was determined to be a suitable diluent medium for controlling the catalyst bed temperature close to the inlet temperature. With 13 g of catalyst and 155 g of diluent, the catalyst maximum temperature were within 2{degree}C from the inlet temperatures. As a result of this work, 210{degree}C and 21 atm were shown to result in low methane selectivity and were used as initial conditions in the catalyst screening test. Ethane, which along with methane is undesirable, is typically produced with low selectivity and follows the same trend as methane. Other work reported here indicated that methane selectivity increases with increasing temperature but is not excessively high at 230{degree}C. Consequently, the catalyst screening test should include an evaluation of the catalyst performance at 230{degree}C. During Run 67, the increase in temperature from 210{degree}C to 230{degree}C was initiated at 30 hours on-stream.

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

    SciTech Connect

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

    1988-01-01

    A cobalt Fischer-Tropsch catalyst (CO/MgO/silica) was reduced and slurried in combination with reduced Cu/ZnO/Al[sub 2]0[sub 3] water-gas-shift catalyst. Combined catalyst system was run at fixed process conditions for more than 400 hours. The system showed stable selectivity. The Cu/ZnO/Al[sub 2]0[sub 3] water-gas-shift catalyst remained reasonably active in the presence of the cobalt catalyst. Hydrocarbon selectivity of the cobalt and Cu/ZnO/Al[sub 2]0[sub 3] catalyst system compared favorably to selectivity of iron-based catalysts. Methane selectivity was slightly higher for the cobalt-based system, but C[sub 5][sup +] selectivity was essentially the same. The hydrocarbon product distribution appeared to exhibit a double-a behavior. a[sub 1] was near 0.80 which is higher than that of iron catalysts, while a[sub 2] was calculated to be 0.86 which is somewhat lower than would be typical for an iron-based catalyst.

  11. An innovative catalyst system for slurry-phase Fischer-Tropsch synthesis: Cobalt plus a water-gas-shift catalyst

    SciTech Connect

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

    1991-07-01

    The feasibility of using a mechanical mixture of a Co/MgO/SiO{sub 2} Fischer-Tropsch catalyst and a Cu-ZnO/Al{sub 2}O{sub 3} water-gas-shift (WGS) catalyst for hydrocarbon synthesis in a slurry reactor has been established. Such a mixture can combine the superior product distribution from cobalt with the high activity for the WGS reaction characteristic of iron. Weight ratios of Co/MgO/SiO{sub 2} to Cu-ZnO/Al{sub 2}O{sub 3} of 0.27 and 0.51 for the two catalysts were studied at 240{degrees}C, 0.79 MPa, and in situ H{sub 2}/CO ratios between 0.8 and 3.0. Each catalyst mixture showed stable Fischer-Tropsch activity for about 400 hours-on-stream at a level comparable to the cobalt catalyst operating alone. The Cu-ZnO/Al{sub 2}O{sub 3} catalyst exhibited a very slow loss of activity under these conditions, but when operated alone it was stable in a slurry reactor at 200--220{degrees}C, 0.79--1.48 MPa, and H{sub 2}/CO in situ ratios between 1.0 and 2.0. The presence of the water-gas-shift catalyst did not affect the long-term stability of the primary Fischer-Tropsch selectivity, but did increase the extent of secondary reactions, such as l-alkene hydrogenation and isomerization.

  12. Preparation of a novel structured catalyst based on aligned carbon nanotube arrays for a microchannel Fischer-Tropsch synthesis reactor

    SciTech Connect

    Chin, Ya-Huei; Hu, Jianli; Cao, Chunshe; Gao, Yufei; Wang, Yong

    2005-12-15

    A novel catalyst microstructure based on aligned multiwall carbon nanotube arrays was synthesized. Its advanced heat and mass transport characteristics coupled with high surface area led to superior performances for Fischer-Tropsch synthesis in a microchannel chemical reactor. The fabrication of such a novel catalyst structure first involved metalorganic chemical vapor deposition (MOCVD) growth of a dense Al2O3 thin film over FeCrAlY foam substrate to enhance adhesion between catalyst layer and metal substrate. Aligned arrays of multiwall carbon nanotubes were grown over the substrate by catalytic decomposition of ethylene. These nanotube bundles were directly attached to the FeCrAlY substrate through a thin layer of oxide thin film. When the outer surfaces of nanobundles were coated with a catalyst layer, a unique hierarchical catalyst structure with nanoporous interstitials between the bundles was created. Thus, engineered catalysts based on such a novel hierarchical structure minimizes mass transfer encountered in the gas-liquid-solid three phase reactions. In addition, high thermal conductivity of carbon nanotube and the direct attachment of these nanobundles to the metal foam allow efficient heat removal from catalytic sites. The advanced heat and mass transfer on this novel structured catalyst was demonstrated in Fischer-Tropsch synthesis in a microchannel fixed bed reactor. The presence of carbon nanotube arrays improved dispersion of active metals and reduced mass transfer limitation, leading to a factor of four enhancement of Fischer-Tropsch synthesis activity. The improved temperature control with the carbon nanotube arrays also allows the Fischer-Tropsch synthesis being operated at temperatures as high as 265 C without reaction runaway favoring methane formation.

  13. Fischer-Tropsch synthesis in slurry-reactor systems. Quarterly report, August 1, 1981-October 31, 1981

    SciTech Connect

    Satterfield, C.N.; Bartos, T.; Huff, G.A. Jr.; Stenger, H.

    1981-01-01

    A large quantity of data were obtained with the fused iron catalyst under intrinsic kinetic conditions, covering for the first time 50 and 200 psi. These data are being analyzed for information about overall rates and product selectivity. Preliminary conclusions about a rate model are presented. Study of the effects of suspended solids on gas-liquid mass transfer was started. Most previous information is on aqueous systems, which is not readily translatable into predicted effects in organic liquids such as Fischer-Tropsch liquids. The most promising and useful method at present appears to be a chemical method based on absorption of CO/sub 2/ into an organic solution of an amine. A paper on a stirred-autoclave apparatus for studying the Fischer-Tropsch synthesis in a slurry bed in included.

  14. 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.

  15. Compositional aspects of iron Fischer-Tropsch catalysts: an x-ray photoelectron

    SciTech Connect

    Kuivila, C.S.

    1987-01-01

    Iron catalysts employed in the Fischer-Tropsch synthesis consist of metallic, carbide, and oxide phases. The catalytic and compositional behavior of prereduced and unreduced iron catalysts were investigated in this study. Catalytic behavior was evaluated by measuring the rates of hydrocarbon formation in a 3:1 H/sub 2//CO mixture at one atmosphere and 250/sup 0/C. Iron phases which evolved near the catalyst surfaces were characterized by x-ray photoelectron spectroscopy, and bulk phases present following the synthesis reactions were determined by Mossbauer spectroscopy. At low conversion levels, prereduced iron catalysts were gradually converted to iron carbide. At total CO conversion levels in the range of 30 to 40%, prereduced catalysts were converted primarily to iron carbide, although some surface oxide phases also formed. Unreduced Fe/sub 2/O/sub 3/ exhibited no initial synthesis activity, but underwent gradual activation and eventually became more active than the prereduced catalysts. The various phases of the iron catalysts were related to varying olefin production rates.

  16. Compositional aspect of iron Fischer-Tropsch catalyst: An XPS/reaction study

    SciTech Connect

    Kuivila, C.S.; Stair, P.C.; Butt, J.B. )

    1989-08-01

    The catalytic and compositional behaviors of prereduced and unreduced iron catalysts for Fischer-Tropsch synthesis were investigated. Catalytic behavior was evaluated by measuring rates of hydrocarbon formation 3:1 H{sub 2}:CO mixture at 1 atm and 250C. Iron phases which evolved near the catalyst surfaces were characterized by X-ray photoelectron spectroscopy, and bulk phases present following reaction were determined by Moessbauer spectroscopy. At low conversion levels the prereduced catalyst was gradually converted to iron carbide with no significant oxide phase formed. Synthesis activities increased initially with the formation of active surface carbon, but eventually lost some activity due to graphitic carbon formation. At higher conversions, the prereduced catalyst showed some formation of surface oxide phases and an inhibition of the synthesis rate due to water adsorption. Surface carbon accumulation was also suppressed under these conditions. Unreduced Fe{sub 2}O{sub 3} showed no initial synthesis activity, but underwent a gradual activation to become even more active than the prereduced catalyst. The oxide catalyst was eventually completely reduced to Fe{sub 3}O{sub 4}, and any metallic phase formed was rapidly converted to iron carbide. Compared to reduced materials, the oxide catalyst accumulated considerably less surface carbon and showed no loss of activity for reaction times up to 48 h. XPS analysis suggests that Fe{sub 3}O{sub 4} is active for synthesis.

  17. Novel Fischer-Tropsch slurry catalysts and process concepts for selective transportation fuel production: Final report

    SciTech Connect

    Withers, H.P. Jr.; Eliezer, K.F.; Mitchell, J.W.

    1987-12-01

    The preparation, characterization and performance of cobalt and ruthenium carbonyl cluster-based catalysts for use in slurry-phase Fischer-Tropsch (FT) technology was investigated. The use of metal carbonyls as active metal precursor allows for the possible control of metal particle size on the support surface and thus offers the potential for better control of activity and selectivity of the FT reaction. Accomplishments included reproducible catalyst preparation, improvements in activity by use of a silica support, understanding diffeences between nitrate and carbonyl precursors, a nd good activity maintenance in the slurry reactor. A CO/sub 2/(CO)/sub 8/Zr(OPr)/sub 4/SiO/sub 2/ catalyst (3.5% CO, 6.6% Zr) was developed as the most active system in the slurry reactor and also gave the best liquid fuel selectivity. Silica support provided the highest catalyst activities. This catalyst was successfully tested in an extended slurry-phase run that achieved 6 months on stream with a 10% loss in activity. Ru catalysts showed the highest activity in the fixed-bed reactor but deactivated rapidly in the slurry reactor. In the analysis of the kinetic data, catalyst deactivation was assumed to proceed linearly between baseline experients at fixed temperture. Causes of the deactivation are not fully understood. 27 refs., 37 figs., 20 tabs.

  18. 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.

  19. Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 6, January 1, 1992--March 31, 1992

    SciTech Connect

    Marcelin, G.

    1992-06-24

    The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: (1) Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch. (2) Addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst. (3) Addition of methanol to slurry phase FT synthesis making iso-olefins. During the sixth quarter we completed the construction of the slurry bubble column reactor (SBCR), conducted initial shake-down experiments in a cold-flow mode, and finalized the selection process of the acid catalysts for conversion of syngas-produced alcohols and isobutylene to MTBE (scheme 2). Tasks 3, 4, and 5 are awaiting complete implementation of the SBCR system.

  20. Bridging the pressure and material gap in heterogeneous catalysis: cobalt Fischer-Tropsch catalysts from surface science to industrial application.

    PubMed

    Oosterbeek, Heiko

    2007-07-21

    The Fischer-Tropsch (FT) process is the heart of many natural gas conversion processes as it enables the conversion of a mixture of CO and H(2) into valuable long-chain hydrocarbons. Here we report on the use of state-of-the-art surface science techniques to obtain information on the relationship between the surface atomic structure of model catalysts and their performance in the Fischer-Tropsch reaction. Cobalt single crystals and polycrystals were modified with non-reducible oxides as to resemble industrial catalysts. Reflection absorption infrared spectroscopy was used for examining the CO adsorption behaviour at room temperature as well as at 493 K at CO pressures spanning 10(-7) to 300 mbar on both (modified) Co single/polycrystals and an industrial catalyst. Polarization modulation was applied to cancel the CO gas phase absorption. Subsequently, they were subjected to reaction tests in the same apparatus at 1 bar and 493 K. This allowed us to close the material, pressure and instrument gap in the field of Fischer-Tropsch synthesis on cobalt-based catalysts. PMID:17612722

  1. 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.

  2. Nanocrystalline Ferrihydrite-Based Catalysts for Fischer-Tropsch Synthesis: Part I. Reduction and Carburization Behavior.

    PubMed

    Chun, Dong Hyun; Park, Ji Chan; Rhim, Geun Bae; Lee, Ho-Tae; Yang, Jung-Il; Jung, Heon

    2016-02-01

    Temperature-programmed reduction using H2 (H2-TPR) and CO (CO-TPR) was carried out to investigate the reduction and carburization behavior of nanocrystalline ferrihydrite-based Fe/Cu/K/SiO2 catalysts for use in Fischer-Tropsch synthesis (FTS). Unlike pure ferrihydrite, the ferrihydrite-based catalysts did not pass through the intermediate decomposition step of ferrihydrite (Fe9O2(OH)23) into hematite (a-Fe2O3) as they were reduced into magnetite (Fe3O4). This is attributed to the enhanced thermal stability induced by SiO2. For the ferrihydrite-based catalysts, the reduction of ferrihydrite into magnetite occurred in two stages because the reduction promoter, Cu, is not homogeneously distributed on the catalyst surfaces. The Cu-rich sites are likely to be reduced in the first stage, and the Cu-lean sites may be reduced in the second stage. After the ferrihydrite is reduced to magnetite, the reduction process of magnetite was similar to that for conventional hematite-based FTS catalysts: 'magnetite --> metallic iron' and 'magnetite --> wüstite (FeO) or fayalite (Fe2SiO4) --> metallic iron' in the H2 atmosphere; 'magnetite --> iron carbides' in the CO atmosphere. PMID:27433641

  3. Slurry-phase Fischer-Tropsch synthesis and kinetic studies over supported cobalt carbonyl derived catalysts

    SciTech Connect

    Withers, H.P. Jr.; Eliezer, K.F.; Mitchell, J.W. )

    1990-09-01

    This paper reports the preparation characterization, and performance of cobalt carbonyl cluster based catalysts for use in slurry-phase Fischer--Tropsch (FT) technology investigated. Using metal carbonyls as active metal precursors allows for the control of metal particle size on the support surface, thus offering the potential for better control of activity and selectivity of the FT reaction. Silica as the support provided the highest catalyst activities. A Co{sub 2}(CO){sub 8}/Zr(OPr){sub 4}/SiO{sub 2} catalyst (3.5% cobalt, 6.6% zirconium) was developed as the most active system in the FT slurry reactor and also gave the best liquid fuel selectivity. Selectivity patterns correlated to the Schulz--Flory prediction. These catalysts exhibited low water/gas shift activity. Diesel fuel product produced by this catalyst was high quality. A kinetic expression that took water inhibition into account was verified, yielding an activation energy of 97 kJ/mol for syngas conversion ranging from 34% to 71% at 240--280{degrees} C.

  4. 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. PMID:27433720

  5. 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.

  6. DEVELOPMENT OF ATTRITION RESISTANT IRON-BASED FISCHER-TROPSCH CATALYSTS

    SciTech Connect

    Adeyinka A. Adeyiga

    2001-09-01

    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. The use of iron-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 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. Recently, fundamental understanding of physical attrition is being addressed by incorporating suitable binders into the catalyst recipe. This has resulted in the preparation of a spray dried Fe-based catalyst having aps of 70 mm with high attrition resistance. This Fe-based 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}{sup +} selectivity of >78% and methane selectivity of <5%. However, further development of the catalyst is needed to address the chemical attrition due to phase changes that any Fe-catalyst goes through potentially causing internal stresses within the particle and resulting in weakening, spalling or cracking. The objective of this research is to develop robust iron-based Fischer-Tropsch catalysts that have suitable activity, selectivity and stability to be used in the slurry bubble column reactor. Specifically we aim to develop to: (i) improve the performance and preparation procedure of the high activity, high attrition resistant, high

  7. Baseline design/economics for advanced Fischer-Tropsch technology. Quarterly report, April--June 1992

    SciTech Connect

    Not Available

    1992-10-01

    Effective September 26, 1991, Bechtel, with Amoco as the main subcontractor, initiated a study to develop a computer model and baseline design for advanced Fischer-Tropsch (F-T) technology for the US Department of Energy`s Pittsburgh Energy Technology Center (PETC). The objectives of the study are to: Develop a baseline design for indirect liquefaction using advanced F-T technology; prepare the capital and operating costs for the baseline design; and develop a process flow sheet simulation (PI-S) model. The baseline design, the economic analysis, and the computer model win be the major research planning tools that PETC will use to plan, guide, and evaluate its ongoing and future research and commercialization programs relating to indirect coal liquefaction. for the manufacture of synthetic liquid fuels from coal. This report is Bechtel`s third quarterly technical progress report covering the period from March 16, 1992 through June 21, 1992. This report consists of seven sections: Section 1 - introduction; Section 2 - summary; Section 3 - carbon dioxide removal tradeoff study; Section 4 - preliminary plant designs for coal preparation; Section 5 - preliminary design for syngas production; Section 6 - Task 3 - engineering design criteria; and Section 7 - project management.

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

    PubMed

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

    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

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. Iron alloy Fischer-Tropsch catalysts. V. FeCo on Y zeolite

    SciTech Connect

    Lin, T.; Schwartz, L.H.; Butt, J.B.

    1986-01-01

    A series of Fe, Co, and FeCo catalysts on Y-zeolite support, prepared both by ion exchange and impregnation, has been investigated and compared with a previously reported series supported on wide-pore SiO/sub 2/. Characterization methods were X-ray diffraction, H/sub 2/ and CO chemisorption, Moessbauer spectroscopy, and atomic absorption. The oxidation, reduction, and carburization behavior of the iron-containing catalysts were observed by Moessbauer spectroscopy. The reversibility of FeY (ion exchanged) in oxidation-reduction cycles was confirmed. The ion-exchanged catalysts (FeY, FeCoY) do not show any iron metal, or alloy or carbide phase after reduction or attempted carburization. In contrast with prior results with silica-supported Fe and FeCo, where there appear to be significant differences, Fe/HY (impregnated) and FeCo/HY appear quite similar in characterization by Moessbauer spectroscopy and in reaction behavior. A 1/1:CO/H/sub 2/ feed was used to investigate the Fischer-Tropsch reaction at 1 atm and 523 K. Some additional runs were made at a total pressure of 13.6 atm. As in prior studies it was found that the CO turnover frequency in general decreases with increasing CO conversion. A higher selectivity for higher molecular weight products is found for HY-supported catalysts, and in all cases an approximate behavior in accord with the Schultz-Anderson distribution was observed. 23 references.

  14. Utilization of cobalt catalyst for high temperature Fischer-Tropsch synthesis in a fluidized bed reactor

    NASA Astrophysics Data System (ADS)

    Mabry, James C.

    The research determined that the improved heat transfer characteristics of a fluidized bed reactor (FBR) will allow the use of cobalt catalyst for high temperature Fischer-Tropsch synthesis (HTFT). Cobalt was loaded onto a gamma alumina support, the catalyst was characterized using TPR, BET/BJH, XRD, and PSA to track changes in the catalyst morphology. The reactor was characterized to determine the minimum fluidization velocity and the maximum velocity prior to entering lean phase fluidization with pneumatic transport of the catalyst. The highest minimum fluidization velocity was found to be about 2800 sccm, there was no maximum velocity found for the reactor setup. Once characterized, the reactor was operated at pressures of 145, 217.6, and 290.1 psig, a syngas flow rate of 4000 sccm, and at temperatures of 330 and 350 °C. The optimal conditions found in this study were 330 °C and 217 psig. At these conditions CO conversion was 83.53 % for a single pass. Methane, CO2, and light gases (C2 -- C4) selectivities were at low rates of 31.43, 5.80, and 3.48 % respectively. Alcohol selectivity at these conditions was non-existent. The olefin and wax selectivities were the lowest of the data set at 7.05 and 3.18 % respectively. Liquid transportation fuels selectivity was the highest at 56.11 %.

  15. 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.

  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 synthesis in slurry reactor systems. Quarterly report, November 1, 1983-January 31, 1984

    SciTech Connect

    Satterfield, C.N.; Bartos, T.; Hanlon, R.; Matsumoto, D.; Stenger, H.

    1984-01-01

    We have now completed and partially analyzed a series of studies on the effects of the nature of the liquid present on activity and seletivity of the Fischer-Tropsch synthesis, and the effects of partial poisoning of the catalyst by H/sub 2/S or dibenzothiophene (DBT). We discovered that the presence of a small amount of DBT (97.8 mg S per g of Fe in the catalyst) cut methane formation nearly in half under a set of reaction conditions of commercial importance (263/sup 0/C, 1.48 MPa, H/sub 2//CO feed ratio = 0.69). The selectivity remained constant for at least 200 hours. This is a very important finding since reduction of methane formation is highly desirable. The catalyst activity simultaneously dropped ten-fold but it should be possible to compensate for this in other ways at least in part such as by operation at higher pressure and/or temperature. Alternately, it may develop that lesser levels of catalyst poisoning may be nearly as effective with less loss of activity. These effects are not observed with H/sub 2/S. As far as we know the effects caused by DBT are brand new and have not been observed before. We plan to exploit this lead in several ways, including optimization of DBT level and reaction conditions; study of other heterocyclic sulfur compounds, effects of activation procedures and correlation of methane selectivity with catalyst carbiding as determined by Mossbauer spectroscopy. Also of some importance was the observation that operation in the presence of an aromatic liquid (phenanthrene) increased the rate of reaction by a factor of 1.5 to 1.8, everything else being held constant.

  18. Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 7, April 1, 1992--June 30, 1992

    SciTech Connect

    Marcelin, G.

    1992-09-24

    The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: addition of i-butylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch; addition of i-butylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst; and addition of methanol to slurry phase FT synthesis making iso-olefins. During the seventh quarter we continued the shake down experiments for the SBCR and conducted an initial aborted run. We have also re-started experiments on Scheme 1, i.e., the addition of iso-butylene during CO hydrogenation. Using a dual bed arrangement, we have demonstrated the synthesis of MTBE from syngas and iso-butylene.

  19. Use of silicate crystallite mesoporous material as catalyst support for Fischer Tropsch reaction

    NASA Astrophysics Data System (ADS)

    Iwasaki, T.; Reinikainen, M.; Onodera, Y.; Hayashi, H.; Ebina, T.; Nagase, T.; Torii, K.; Kataja, K.; Chatterjee, A.

    1998-06-01

    Novel uniform mesoporous materials (silicate crystallite mesoporous material, SCMM) were synthesized by hydrothermal treatment of Si, Mg and/or Al containing hydroxide precipitates, along with quaternary ammonium salt, and were applied as catalyst support for Fischer-Tropsch reaction. SCMM is composed of aggregates of homogeneous layer silicate crystallites, as identified by X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM) photographs which are structurally analogous to smectite clay. The mesopore of SCMM corresponds to interparticle space of disk-shaped crystallites (6-25 nm in diameter) aggregated by edge-to-face bonding. Two kinds of SCMM with variable negative charge locations were used as support materials of Co-catalysts for hydrogenation of CO. Conversion of CO was high on SCMM compared with that of silica gel. Furthermore, the main products obtained were hydrocarbons. In case of SCMM type with negative charge near the surface, olefins and branched hydrocarbons were efficiently produced in CO conversion reaction; where as another SCMM type having negative charge at the middle of crystallite platelets produced mainly normal hydrocarbons for the same reaction. This may be due to the role of the negative charge of SCMM which affects the chemical state of Co-catalyst supported on SCMM. The function of SCMM as compared to other mesoporous materials is better in terms of homogeneous and site-specific distribution of negative charge, which is further helpful in controlling the surface phenomenon as confirmed by the existence of linear CO species adsorbed on Co.

  20. 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

  1. Manganese-oxide-supported iron Fischer-Tropsch synthesis catalysts: physical and catalytic characterization

    SciTech Connect

    Kreitman, K.M.; Baerns, M.; Butt, J.B.

    1987-06-01

    It has been claimed that catalysts containing iron and manganese are especially selective for production of low molecular weight olefins in the Fischer-Tropsch (FT) synthesis. In this study a new system, manganese-oxide-supported iron, Fe/MnO, was prepared, subjected to various calcination and reduction treatments, and then employed as a FT catalyst. Reaction studies were run with approximately 1/1: CO/H/sub 2/ feed at 515 and 540 K and 7.8 and 14.8 bar pressure. Although low conversions were employed, the synthesis rate decreased strongly with increasing conversion. Compared to conventional Fe catalysts, the Fe/MnO was more active for water-gas shift and less selective for methane and alcohols, especially at higher conversions, lower temperature, and higher pressure. Olefin selectivity was high, hydrogen chemisorption was depressed, and secondary hydrogenation was not apparent. In general it is concluded that the manganese-supported iron does promote FT selectivity for low molecular weight olefins, but at the expense of high CO/sub 2/ formation.

  2. 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.

  3. Activation studies with a precipitated iron catalyst for Fischer-Tropsch synthesis. II. Reaction studies

    SciTech Connect

    Bukur, D.B.; Nowicki, L.; Manne, R.K.; Lang, Xiaosu

    1995-09-01

    Effects of pretreatment conditions on catalyst performance (activity, selectivity, and stability with time) during Fischer-Tropsch (FT) synthesis were studied in a fixed-bed reactor using a commercial precipitated iron catalyst (100 Fe/5 Cu/4.2K/25 SiO{sub 2} on a mass basis). The catalyst activity increased slightly with time-on-stream after hydrogen reductions, which was accompanied with conversion of metallic iron and part of iron oxides to {epsilon}{prime}-carbide ({epsilon}{prime}-Fe{sub 22}C). Initial activity of the H{sub 2}-reduced catalyst at 280{degrees}C for 8 or 24 h was markedly lower than that obtained in other tests. This is attributed to slow carburization of large oxide particles and partial poisoning of catalyst sites by migration of sulfur from the bulk to the surface of the catalyst during the reduction. Pretreatments with carbon monoxide and syngas resulted in partial conversion of Fe{sub 2}O{sub 3} to {chi}-carbide ({chi}-Fe{sub 5}C{sub 2}). During FT synthesis the CO- and the syngas-pretreated catalyst deactivated slowly with time-on-stream, due to partial conversion of {chi}-carbide to less active iron oxide phases and buildup of carbonaceous deposits which block the active sites. The hydrogen-reduced catalyst at 280{degrees}C, for 1-24h, produced more methane and gaseous hydrocarbons than the CO- or the syngas-pretreated catalyst and favored secondary reactions (1-olefin hydrogenation, isomerization, and readsorption). 41 refs., 5 figs., 2 tabs.

  4. Researching Fe catalyst suitable for CO{sub 2}-containing syngas for Fischer-Tropsch synthesis

    SciTech Connect

    Wensheng Ning; Naoto Koizumi; Muneyoshi Yamada

    2009-09-15

    Fischer-Tropsch (FT) synthesis is a technology to produce liquid fuels from coal, natural gas, and biomass as an alternate to crude oil. However, the quantity of emitted CO{sub 2} from the FT process consisting of syngas preparation, FT synthesis, and product workup is one of the serious disadvantages of FT process. The conversion of CO{sub 2} into hydrocarbons is one of the promising methods to decrease CO{sub 2} emissions. Effects of promoter addition on the activity of precipitated Fe catalysts for the conversion of CO{sub 2} were studied using pure CO{sub 2} and CO{sub 2}-containing syngas feeds. The results suggested that CO{sub 2} can be activated by suitable promoter(s) for hydrocarbon synthesis at low temperature. Low K content is suitable for increasing hydrocarbon yield. The Fe catalysts promoted by equal Zn and Cu have higher CO and CO{sub 2} conversion and decreased CH{sub 4} selectivity. 36 refs., 7 figs., 3 tabs.

  5. In situ reduction study of cobalt model Fischer-Tropsch synthesis catalysts.

    PubMed

    du Plessis, Hester Esna; Forbes, Roy Peter; Barnard, Werner; Erasmus, Willem Johannes; Steuwer, Axel

    2013-07-28

    Fischer-Tropsch (FT) synthesis is an important process to manufacture hydrocarbons and oxygenated hydrocarbons from mixtures of carbon monoxide and hydrogen (syngas). The catalysis process occurs on, for example, cobalt metal surfaces at elevated temperatures and pressures. A fundamental understanding of the reduction pathway of supported cobalt oxides, and the intermediate species present during the activation, can assist in developing improved industrial supported cobalt catalysts. Hard synchrotron X-rays have the unique ability to probe atomic processes both in terms of phases present as well as the crystallographic and local structure (using the pair distribution function approach) under realistic conditions. In this manuscript we present results from measurements during in situ hydrogen activation of a model Co/alumina catalyst using in situ synchrotron X-ray powder diffraction and pair-distribution function (PDF) analysis on beam line ID31 at the ESRF in Grenoble, France. The PDF analysis showed a substantially improved understanding of the reduction of cobalt oxides, as for the first time all cobalt could be accounted for by using total scattering analysis. PMID:23752408

  6. Fischer-Tropsch slurry phase process variations to understand wax formations: Quarterly report, January 1, 1988-March 31, 1988

    SciTech Connect

    Satterfield, C.N.

    1988-01-01

    A method has been developed for caluclating the three parameters needed to characterize the carbon number distribution of products of the Fischer-Tropsch synthesis. using non-linear regression, experiemental data are fit by a modified Schulz-Flory model which has two chain growth probabilities. Excellent fit is shown for data from precipitated and fused iron catalysts. The model is used to calculate selectivity information of interest in catalyst comparison and reactor design. Advantages of this model over asymptotic regression methods are discussed in detail. 26 refs., 6 figs.

  7. 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.

  8. 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.

  9. SBA-15-Supported Iron Catalysts for Fischer-Tropsch Production of Diesel Fuel

    SciTech Connect

    Kim,D.; Dunn, B.; Huggins, F.; Huffman, G.; Kang, M.; Yie, J.; Eyring, E.

    2006-01-01

    Iron supported on SBA-15, a mesoporous structured silica, has been developed as a catalyst for the Fischer-Tropsch synthesis of hydrocarbons. The catalysts retain the high surface area of the support, {approx}500 m{sup 2}/g, average pore size, and pore volume. Inclusion of aluminum into the SBA-15 did not significantly alter these parameters. XRD, XAFS, and Moessbauer spectroscopies were used to characterize the catalyst before and after being subjected to the reaction conditions. Prior to reaction, the iron was distributed among {alpha}-Fe{sub 2}O{sub 3}3, ferrihydrite, and minor {gamma}-Fe{sub 2}O{sub 3}. After reaction, the iron phases detected were nonmagnetic iron oxides, iron carbide, and metallic iron. The length of the induction period typically seen with iron-based F-T catalysts was strongly dependent on the amount of aluminum present in the catalyst. With no aluminum, the induction period lasted about 25 h, whereas the induction period decreased to less than 5 h with an Al:Si mass ratio of 0.010. A further increase in aluminum content lengthened the induction period, but always remained less than that without aluminum. Catalyst activity and product selectivity were also strongly dependent on aluminum content with the maximum diesel fuel fraction, C{sub 11+}, occurring with the Al:Si ratio of 0.010 and a CO conversion of 37%. The small concentration of aluminum may serve to increase the rate of iron carbide formation, whereas higher concentrations may begin to inhibit the rate.

  10. SBA-15-supported iron catalysts for Fischer-Tropsch production of diesel fuel

    SciTech Connect

    Dae Jung Kim; Brian C. Dunn; Frank Huggins; Gerald P. Huffman; Min Kang; Jae Eui Yie; Edward M. Eyring

    2006-12-15

    Iron supported on SBA-15, a mesoporous structured silica, has been developed as a catalyst for the Fischer-Tropsch synthesis of hydrocarbons. The catalysts retain the high surface area of the support, {approximately}500 m{sup 2}/g, average pore size, and pore volume. Inclusion of aluminum into the SBA-15 did not significantly alter these parameters. XRD, XAFS, and Moessbauer spectroscopies were used to characterize the catalyst before and after being subjected to the reaction conditions. Prior to reaction, the iron was distributed among {alpha}-Fe{sub 2}O{sub 3}, ferrihydrite, and minor {gamma}Fe{sub 2}O{sub 3}. After reaction, the iron phases detected were nonmagnetic iron oxides, iron carbide, and metallic iron. The length of the induction period typically seen with iron-based F-T catalysts was strongly dependent on the amount of aluminum present in the catalyst. With no aluminum, the induction period lasted about 25 h, whereas the induction period decreased to less than 5 h with an Al:Si mass ratio of 0.010. A further increase in aluminum content lengthened the induction period, but always remained less than that without aluminum. Catalyst activity and product selectivity were also strongly dependent on aluminum content with the maximum diesel fuel fraction, C{sub 11+}, occurring with the Al:Si ratio of 0.010 and a CO conversion of 37%. The small concentration of aluminum may serve to increase the rate of iron carbide formation, whereas higher concentrations may begin to inhibit the rate. 23 refs., 6 figs., 2 tabs.

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

    SciTech Connect

    MARK C. THIES; PATRICK C. JOYCE

    1998-07-31

    The objective of this research project is 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}, will be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300 C. Initial work is being performed using n-hexane as the solvent. The success of the project depends on two factors. First, the supercritical solvent must be able to dissolve the F-T wax; furthermore, this must be accomplished at conditions that do not entrain the solid catalyst. Second, the extraction must be controlled so as not to favor the removal of the low molecular weight wax compounds. That is, a constant carbon-number distribution in the wax slurry must be maintained at steady-state column operation. Three major tasks are being undertaken to evaluate our proposed SCF extraction process. Task 1: Equilibrium solubility measurements for model F-T wax components in supercritical fluids at conditions representative of those in a SBC reactor. Task 2: Thermodynamic modeling of the measured VLE data for extending our results to real wax systems. Task 3: Process design studies of our proposed process. Additional details of the task structure are given.

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

    SciTech Connect

    MARK C. THIES; PATRICK C. JOYCE

    1998-10-31

    The objective of this research project is 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}, will be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300 C. Initial work is being performed using n-hexane as the solvent. The success of the project depends on two factors. First, the supercritical solvent must be able to dissolve the F-T wax; furthermore, this must be accomplished at conditions that do not entrain the solid catalyst. Second, the extraction must be controlled so as not to favor the removal of the low molecular weight wax compounds. That is, a constant carbon-number distribution in the wax slurry must be maintained at steady-state column operation. Three major tasks are being undertaken to evaluate our proposed SCF extraction process. Task 1: Equilibrium solubility measurements for model F-T wax components in supercritical fluids at conditions representative of those in a SBC reactor. Task 2: Thermodynamic modeling of the measured VLE data for extending our results to real wax systems. Task 3: Process design studies of our proposed process. Additional details of the task structure are given.

  13. Studying Fischer-Tropsch catalysts using transmission electron microscopy and model systems of nanoparticles on planar supports.

    SciTech Connect

    Thune, P. C.; Weststrate, C. J.; Moodley, P.; Saib, A. M.; van de Loosdrecht, J.; Miller, J. T.; Niemantsverdriet, J. W.

    2011-01-01

    Nanoparticle model systems on planar supports form a versatile platform for studying morphological and compositional changes of catalysts due to exposure to realistic reaction conditions. We review examples from our work on iron and cobalt catalysts, which can undergo significant rearrangement in the reactive environment of the Fischer-Tropsch synthesis. The use of specially designed, silicon based supports with thin film SiO{sub 2} enables the application of transmission electron microscopy, which has furnished important insight into e.g. the mechanisms of catalyst regeneration.

  14. A study on Raney iron catalyst for Fischer-Tropsch process in a slurry-phase reactor

    SciTech Connect

    Lu, Y.; Zhang, Z.; Zhou, J.

    1997-12-31

    Raney Fe, prepared by extracting Al from Fe-Al alloy, exhibits a better activity during slurry phase FT synthesis and shows distinct selectivity in low weight hydrocarbon (alkanes). Its properties, a BET surface area of at least 22m{sup 2}/g, an average pore diameter of 30nm, and similar attrition resistance as fused iron, significantly contribute to the catalyst performance such as activity, product selectivity and free separation from the waxes. This paper describes catalyst preparation and performance tests in a slurry Fischer-Tropsch synthesis. Three catalysts were compared: fused iron, precipitated iron, and Raney iron.

  15. Manganese oxide-supported iron Fischer-Tropsch synthesis catalysts: physical and catalytic characterization

    SciTech Connect

    Kreitman, K.M.

    1986-01-01

    In this study, manganese oxide-supported iron (Fe/MnO) was prepared by impregnation of powdered manganese (II) oxide with aqueous iron(III) nitrate and subjected to various calcination and reduction treatments. It was then employed as a catalyst for Fischer-Tropsch Synthesis (FTS) and its steady-state activity and selectivity behavior was observed. The FTS reaction studies were run with nearly equimolal carbon monoxide/hydrogen feed at 515 and 540 K, 7.9 and 14.8 bar pressure. Feed conversion level was kept low in order to avoid transport limitations, and was varied by adjusting space velocity. The FTS reaction rate decreased strongly with increasing conversion. Compared to unpromoted iron catalysts, the Fe/MnO catalysts were more active for the water-gas shift reaction and less selective for methane and alcohols, especially at higher conversion, lower temperature and higher pressure. The olefin selectivity was high and secondary hydrogenation was not apparent. Catalysts calcined at higher temperature exhibited stronger effects of promotion, and yielded unusually high selectivity for C/sub 2/ to C/sub 4/ hydrocarbons at low temperature and high pressure. The general conclusion is that manganese promotion or iron can promote FTS selectivity towards low molecular weight olefins, but at the expense of high carbon dioxide formation. The Fe/MnO was also physically examined using Moessbauer spectroscopy and X-ray diffraction. Iron and manganese were found to interact strongly in the calcined catalyst, though extensive phase separation occurred during reduction. The promoting effects are apparently due to partial surface coverage of iron with MnO, the extent of which is enhanced by wetter reducing conditions.

  16. Technology development for iron Fischer-Tropsch catalysis. Quarterly technical progress report No. 2, January 1, 1995--March 31, 1995

    SciTech Connect

    Davis, B.H.

    1995-05-02

    The Fischer-Tropsch synthesis has been studied over the best low-alpha catalyst developed at the CAER. A wide range of synthesis gas conversions were obtained by varying the space velocity. The experimental results show that: (1) the rate of the water gas shift reaction is lower than the rate of the Fischer-Tropsch reaction at low conversions (< 60%) whereas it closely approaches the rate of the Fischer-Tropsch synthesis at high conversions, (2) the fraction of CO converted to hydrocarbons is higher at low and intermediate conversions whereas it is smaller at high conversions, (3) the H{sub 2}/CO ratio of the product gas is equal to the H{sub 2}/CO ratio of the inlet synthesis gas at an intermediate conversion level of 67%. These findings suggest that it would be beneficial to carry out the reaction at intermediate conversions. This would result in an optimum use of CO to produce hydrocarbons rather than CO{sub 2}. High overall conversions can be obtained by either using a second reactor or recycling the product gas using a single reactor. If the intermediate conversion in a single pass is maintained at 67% there would be no need to adjust the H{sub 2}/CO ratio of the recycle stream or the feed to the second reactor as the product gas from a single pass would have the same H{sub 2}/CO ratio as the feed synthesis gas. The optimum reaction rate expression for synthesis gas conversion which has been developed for this catalyst shows that CO is strongly adsorbed on the catalyst and that the reaction products such as water and CO{sub 2} do not inhibit the reaction rate.

  17. 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. PMID:22083868

  18. Characterization of working iron Fischer-Tropsch catalysts using quantitative diffraction methods

    NASA Astrophysics Data System (ADS)

    Mansker, Linda Denise

    This study presents the results of the ex-situ characterization of working iron Fischer-Tropsch synthesis (F-TS) catalysts, reacted hundreds of hours at elevated pressures, using a new quantitative x-ray diffraction analytical methodology. Compositions, iron phase structures, and phase particle morphologies were determined and correlated with the observed reaction kinetics. Conclusions were drawn about the character of each catalyst in its most and least active state. The identity of the active phase(s) in the Fe F-TS catalyst has been vigorously debated for more than 45 years. The highly-reduced catalyst, used to convert coal-derived syngas to hydrocarbon products, is thought to form a mixture of oxides, metal, and carbides upon pretreatment and reaction. Commonly, Soxhlet extraction is used to effect catalyst-product slurry separation; however, the extraction process could be producing irreversible changes in the catalyst, contributing to the conflicting results in the literature. X-ray diffraction doesn't require analyte-matrix separation before analysis, and can detect trace phases down to 300 ppm/2 nm; thus, working catalyst slurries could be characterized as-sampled. Data were quantitatively interpreted employing first principles methods, including the Rietveld polycrystalline structure method. Pretreated catalysts and pure phases were examined experimentally and modeled to explore specific behavior under x-rays. Then, the working catalyst slurries were quantitatively characterized. Empirical quantitation factors were calculated from experimental data or single crystal parameters, then validated using the Rietveld method results. In the most active form, after pretreatment in H 2 or in CO at Pambient, well-preserved working catalysts contained significant amounts of Fe7C3 with trace alpha-Fe, once reaction had commenced at elevated pressure. Amounts of Fe3O 4 were constant and small, with carbide dpavg < 15 nm. Small amounts of Fe7C3 were found in unreacted

  19. 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.

  20. Synthesis of octane enhancer during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 4, July 1, 1991--September 30, 1991

    SciTech Connect

    Marcelin, G.

    1991-12-15

    The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch. Addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst. Addition of methanol to slurry phase FT synthesis making iso-olefins.

  1. Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 3, April 1, 1991--June 30, 1991

    SciTech Connect

    Marcelin, G.

    1991-10-15

    The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butytl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: (1) Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch; (2) addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst; and, (3) addition of methanol to slurry phase FT synthesis making iso-olefins.

  2. Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 5, October 1, 1991--December 31, 1991

    SciTech Connect

    Marcelin, G.

    1992-06-10

    The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch. Addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst. Addition of methanol to slurry phase FT synthesis making iso-olefins.

  3. 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

  4. Tailored fischer-tropsch synthesis product distribution

    DOEpatents

    Wang, Yong; Cao, Chunshe; Li, Xiaohong Shari; Elliott, Douglas C.

    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.

  5. DEVELOPMENT OF ATTRITION RESISTANT IRON-BASED FISCHER-TROPSCH CATALYSTS

    SciTech Connect

    Adeyinka A. Adeyiga

    2003-12-01

    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 Fe FT 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. 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. The catalysts were prepared by co-precipitation, followed by binder addition and spray drying at 250 C in a 1 m diameter, 2 m tall spray dryer. The binder silica content was varied from 0 to 20 wt %. The results show that use of small amounts of precipitated SiO{sub 2} alone in spray-dried Fe catalysts can result in good attrition resistance. All catalysts investigated with SiO{sub 2} wt% {le} 12 produced fines less than 10 wt% during the jet cup attrition test, making them suitable for long-term use in a slurry bubble column reactor. Thus, concentration rather than type of SiO{sub 2

  6. Development of a stable cobalt-ruthenium Fischer-Tropsch catalyst. Technical progress report No. 14, January 1, 1993--March 31, 1993

    SciTech Connect

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

    1994-05-01

    The objective of this contract is to examine the relationship between catalytic properties and the function of cobalt Fischer-Tropsch catalysts and to apply this fundamental knowledge to the development of a stable cobalt-based catalyst with a low methane-plus-ethane selectivity for use in slurry reactors.

  7. Thermodynamic analysis of nanoparticle size effect on kinetics in Fischer-Tropsch synthesis by lanthanum promoted iron catalyst

    NASA Astrophysics Data System (ADS)

    Nakhaei Pour, Ali; Housaindokht, Mohammad Reza; Behroozsarand, Alireza; Khodagholi, Mohammad Ali

    2014-08-01

    The kinetic parameters of the Fischer-Tropsch synthesis (FTS) on iron catalyst are analyzed by size-dependent thermodynamic method. A Langmuir-Hinshelwood kinetic equation is considered for evaluation of catalytic activity of lanthanum promoted iron catalyst. A series of unsupported iron catalysts with different particle sizes were prepared via microemulsion method. The experimental results showed that catalyst activity pass from a maximum value by increasing the iron particle size. Also, data presented that iron particle size has considerable effects on adsorption parameters and FTS rates. The ratio of surface tension ( σ) to nanoparticle radius ( r) is important in FTS reaction on iron catalyst. Finally, the results showed that by increasing of iron particle size from 18 to 45 nm the activation energies of catalysts and heats of adsorption of catalysts as two main parameters of FTS reaction increased from 89 to 114 kJ/mol and from 51 to 71 kJ/mol, respectively.

  8. Study of the effects of potassium addition to supported iron catalysts in the Fischer-Tropsch reaction

    SciTech Connect

    Miller, D.G.; Moskovits, M.

    1988-10-20

    The Fischer-Tropsch activity of supported iron catalysts prepared via electrochemical techniques has been evaluated as a function of potassium addition. Catalyst pretreatment in 0.09, 0.18, and 0.27 M K/sub 2/CO/sub 3/ solutions generated potassium levels of 1.7, 2.8, and 3.9 wt %, respectively. Pretreatment in 0.18 M KOH provided a catalyst with 2.3 wt% potassium and facilitated comparison of the effects of the basicity of the pretreatment solution upon catalyst activity. A maximum in catalyst activity and CO conversion was noted upon increasing K content, followed by a sharp decline in activity at potassium levels in excess of the maximum. The hydrogenation ability of the catalyst decreased, and a shift to higher molecular weight products was observed, with increasing potassium content. The type of pretreatment solution had little effect on the catalyst activity or the product selectivity.

  9. Fischer-Tropsch synthesis in slurry-reactor systems. Quarterly report, November 1, 1981 to January 31, 1982

    SciTech Connect

    Satterfield, C.N.; Bartos, T.; Huff, G.A. Jr.; Stenger, H.

    1982-01-01

    A detailed study of mass transfer effects with a reduced fused magnetite catalyst has now been completed and is summarized in an appended paper, Mass Transfer and Product Selectivity in a Mechanically-Stirred Fischer-Tropsch Slurry Reactor, by Charles N. Satterfield and George A. Huff, Jr. Analysis of our heavier hydrocarbon products indicates that they yield a value of ..cap alpha.. = 0.93 on a Flory plot, considerably higher than the values of ..cap alpha.. of about 0.7 found with lighter products. Iron catalysts may exhibit two kinds of sites with considerably different kinetic behavior. At the request of Drs. Sapienza and Sleigeir of the Brookhaven National Laboratory, we ran a sample of their SOSS catalyst in our reactor facility at 100 psig. Activity was low, but this may have been because this particular catalyst is possibly better suited for higher pressures.

  10. The selective catalytic cracking of Fischer-Tropsch liquids to high value transportation fuels. Report number 23: Quarterly technical progress report for third quarter fiscal year 1992 (April 1--June 30, 1992)

    SciTech Connect

    Reagan, W.J.

    1992-12-31

    Amoco Oil Company is investigating a selective catalytic cracking process to convert the Fischer-Tropsch naphtha and wax fractions to high value transportation fuels. The wax feedstock for this program, a commercial sample of Fischer-Tropsch product from Sasol, is a high melting point, (>220 F), high boiling range (50% boiling above 1,000 F), largely paraffinic material. Work this Quarter centers on the study of various types of HZSM-5 and Y zeolite catalysts. The wax cracking tests on the pilot plant unit were completed last Quarter. The initial product yields have now been corrected for gas and liquid component distribution. Several additional product quality measurements have been completed. The distillate product fraction, boiling between 430--650 F, obtained from the Y zeolite catalyst run, has a high quality Cetane Index of 59. These test results also show high conversion (85%+) of the wax feedstock to light gases and gasoline. The ranking of the three zeolite catalyst types for C{sub 4}-C{sub 5} iso-olefin production is similar to the findings of the small scale screening test program. It is not possible to obtain test results at a wide variety of conversion levels on the pilot plant due to operating constraints.

  11. 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.

  12. 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.

  13. Research Opportunities for Fischer-Tropsch Technology

    SciTech Connect

    Jackson, Nancy B.

    1999-06-30

    Fischer-Tropsch synthesis was discovered in Germany in the 1920's and has been studied by every generation since that time. As technology and chemistry, in general, improved through the decades, new insights, catalysts, and technologies were added to the Fischer-Tropsch process, improving it and making it more economical with each advancement. Opportunities for improving the Fischer-Tropsch process and making it more economical still exist. This paper gives an overview of the present Fischer-Tropsch processes and offers suggestions for areas where a research investment could improve those processes. Gas-to-liquid technology, which utilizes the Fischer Tropsch process, consists of three principal steps: Production of synthesis gas (hydrogen and carbon monoxide) from natural gas, the production of liquid fuels from syngas using a Fischer-Tropsch process, and upgrading of Fischer-Tropsch fuels. Each step will be studied for opportunities for improvement and areas that are not likely to reap significant benefits without significant investment.

  14. Effect of 1-olefin addition on supercritical phase Fischer-Tropsch synthesis over Co/SiO{sub 2} catalyst

    SciTech Connect

    Yan, S.R.; Zhang, Z.X.; Zhou, J.L.; Fan, L.; Fujimoto, Kaoru

    1997-12-31

    Hydrocarbon wax produced by Fischer-Tropsch Synthesis (FTS) has been used in many fields for its high quality, such as high melting point, high hardness value, low viscosity, being nitrogen sulfur and aromatics-free. Selective synthesis of FT wax has generated great interest, especially in the case of lower oil-prices. As a polymerization process, however, in conventional gas phase FTS, selectivity of wax is constrained by the Anderson-Schultz-Flory (ASF) kinetics. Supercritical phase Fischer-Tropsch synthesis co-fed with 1-tetradecene over Co/SiO{sub 2} catalysts has been carried out. It was found that added 1-tetradecene could reach the surface of the catalyst by the aid of a supercritical fluid, and participate in the chain growth process there, which was indistinguishable from the original chain propagation. Consequently, the yield of hydrocarbons larger than C{sub 14} increased significantly, while the selectivity of C{sub 1}-C{sub 13} decreased correspondingly, which made the carbon number distribution deviate from ASF kinetics drastically. In addition, the analytical results of wax showed that average molecular weight and degree of saturation of the wax increased, while the content of oxygenates in the wax decreased due to the addition of 1-tetradecene.

  15. Kinetics of the Fischer-Tropsch reaction on a precipitated promoted iron catalyst. 1. Experimental procedure and results

    SciTech Connect

    Lox, E.S.; Froment, G.F. )

    1993-01-01

    The Fischer-Tropsch reaction on a commercial promoted precipitated iron catalyst was studied in a tubular reactor under non-deactivating conditions of temperatures between 523 and 623 K, pressures between 0.6 and 2.1 MPa, hydrogen to carbon monoxide feed ratios between 3.0 and 6.0 mol/mol, and W/F[degree][sub CO] values between 9.2 and 63.0 kg[center dot]s/mol. The selectivity for carbon dioxide, methane, and hydrocarbons of different functionality with 2-15 carbon atoms in the molecule was obtained as a function of the carbon monoxide conversion, the reactor temperature, and the total pressure. The initial rate of formation of these products was measured as a function of the total pressure and the partial pressures of hydrogen and carbon monoxide at the reactor inlet. These experiments, combined with the information gained from the catalyst characterization, indicated that carbon dioxide is formed by the water gas shift reaction. Methane, n-paraffins, and 1-olefins with two and more carbon atoms in the molecule are all primary products of the Fischer-Tropsch reaction. The composition of the hydrocarbon product fraction, as a function of the number of carbon atoms in the hydrocarbon molecule, could be described by the Schulz-Flory distribution, although it is shown that the latter only approximately holds for the effluent of an integral reactor.

  16. Development of a stable cobalt-ruthenium Fischer-Tropsch catalyst. Technical progress report No. 15, 1 April 1993--30 June 1993

    SciTech Connect

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

    1994-06-01

    The high cobalt catalyst described in the previous quarterly report of this contract has been bound and evaluated in the fixed-bed and slurry autoclave pilot plants. The fixed-bed test showed it to be less active after binding than before. The purpose of binding is to provide a granular catalyst suitable for use in liquid phase Fischer-Tropsch (LPFT) processing. In such processing a granular catalyst is required to facilitate its separation from the FT wax product by mechanical means. The bound catalyst was evaluated in the slurry autoclave under LPFT conditions. In this test the temperature of the catalyst could be more precisely controlled at target than in the fixed-bed test due to the large amount of diluent and continual stirring. When operated at a temperature sufficient to induce the same conversion as in the fixed-bed test, the methane selectivity was 10 mole % --- 2% less than in the fixed-bed test. The high cobalt catalyst, bound and unbound, in the fixed-bed or slurry autoclave pilot plants, was not conversion stable. At a given temperature it seemed to approach a conversion line out, however, catalysts more stable at high conversion are required. The unbound catalyst contained more cobalt than previous unbound catalysts in this work. Furthermore, it contained a small amount of ruthenium. Either or both of these properties could have been responsible for the superior activity.

  17. 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.

  18. Selective Fischer-Tropsch synthesis on metal powder catalysts prepared by the potassium reduction of halides in THF

    SciTech Connect

    Miyake, M.; Takebe, K.; Nomura, M.

    1987-06-01

    Metal powders such as Fe, Co, Ni, Fe-Co, and Fe-Ni prepared by reducing metal iodides or bromides with potassium metal in refluxing THF were used as catalysts for Fischer-Tropsch syntheses. These metal powders contained very small particles and have BET surface areas (28-36 m/sup 2//g). The metal powder catalysts, such as Fe and Fe-Co (80:20), gave 1-butene with more than 35 wt% selectivity at a rather high CO conversion of over 10 wt% at 533-553 K, while products on the Co catalyst obeyed conventional Schulz-Flory type distribution. The Ni catalyst showed little activity. Effects of reaction variables (temperature, H/sub 2//CO feed gas ratio, and composition of Fe-Co) were investigated.

  19. A comparison of the activity, selectivity and kinetics of several iron-based Fischer-Tropsch catalysts

    SciTech Connect

    Dictor, R.A.; Bell, A.T.

    1986-03-01

    Much attention in the area of Fischer-Tropsch chemistry has been directed at slurry-phase reactor systems because of facilitated temperature control and the ability to operate continuously using hydrogen-lean feeds. The ability to predict and control the behavior of bubble column Ft reactors requires a detailed understanding of the reaction kinetics and mass transfer limitations. The authors examined the effects of temperature, reactant partial pressures, gas velocity and feed ratio on catalyst activity and selectivity for a number of catalysts: Fe/sub 2/O/sub 3/, potassium-promoted Fe/sub 2/O/sub 3/, Fe, Fe/sub 3/C, and a fused iron ammonia synthesis catalyst. The goal of this communication is to determine the effects of structural features (e.g., surface area, promoters, etc.) on the activities and selectivities of these catalysts.

  20. Enhanced Fischer-Tropsch synthesis performance of iron-based catalysts supported on nitric acid treated N-doped CNTs

    NASA Astrophysics Data System (ADS)

    Li, Zhenhua; Liu, Renjie; Xu, Yan; Ma, Xinbin

    2015-08-01

    Iron-based catalysts supported on N-doped CNTs (NCNTs) treated by various concentrations of nitric acid for Fischer-Tropsch synthesis (FTS) were investigated. An improved catalytic performance for the iron catalyst supported on acid treated NCNTs was obtained and the suitable nitric acid concentration was 10 M. The physiochemical properties of the NCNTs and the corresponding catalysts were characterized by BET, TEM, XRD, XPS, TGA and H2-TPR. The acid treatment removed the impurity and amorphous carbon, damaged the bamboo-like structure and increased the number of oxygen-containing functional groups and graphitization degree on the NCNTs. The more iron particles located inside the channels of NCNTs, the better catalytic FTS performance due to high dispersion and reducibility.

  1. Technology development for iron Fischer-Tropsch catalysts. Technical progress report No. 12, June 26, 1993--September 26, 1993

    SciTech Connect

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

    1994-07-01

    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 scale-up 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%.

  2. Technology development for iron Fischer-Tropsch catalysts. Technical progress report No. 2, December 26, 1990--March 26, 1991

    SciTech Connect

    Not Available

    1991-12-31

    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 catalyst for process development and long-term testing in slurry bubble-column reactors. With a feed containing H{sub 2} and CO in the molar ratio of 0.5 to 1.0, the catalyst performance target in the slurry bubble-column reactor 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%.

  3. Technology development for iron Fischer-Tropsch catalysts. Technical progress report No. 3, March 27, 1991--June 30, 1991

    SciTech Connect

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

    1991-12-31

    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 scale up procedure for large-scale synthesis of such catalysts for process development and long-term testing in slurry bubble-column reactors. The catalyst performance target in the slurry bubble-column reactor is 88% CO + H{sub 2} conversion at a minimum space velocity of 2.4 NL/hr/gFe. Typical feed used to attain this level of conversion is preferred to have H{sub 2} and CO in the molar ratio of 0.5 to 1.0. The desired sum of methane and ethane selectivities is no more than 4%, and the conversion loss per week is not to exceed 1%.

  4. Technology development for iron Fischer-Tropsch catalysts. Technical progress report No. 1, September 26, 1990--December 26, 1990

    SciTech Connect

    Not Available

    1990-12-31

    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 scale-up procedure for large-scale synthesis of such catalysts for process development and long-term testing in slurry bubble column reactors. With a feed containing H{sub 2}:CO in the ratio of 0.5 to 1.0, the catalyst performance target in the slurry bubble column reactor is 88% CO + H{sub 2}conversion at a minimum space velocity of 2.4 NL/h/gFe. The methane + ethane selectivity is desired to be no more than 4% and the conversion loss per week is not to exceed 1%.

  5. 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%.

  6. Technology development for iron Fischer-Tropsch catalysts. Technical progress report number 13, 26 September 1993--26 December 1993

    SciTech Connect

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

    1994-08-01

    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 scale up 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%. Results are presented from experimental work performed during this report period.

  7. Characterization of catalysts by Mossbauer spectroscopy: An application to the study of Fischer-Tropsch, hydrotreating and super Claus catalysts

    NASA Astrophysics Data System (ADS)

    van der Kraan, A. M.; Boellaard, E.; Crajé, M. W. J.

    1993-04-01

    Mössbauer spectroscopy is an excellent in-situ technique for the identification of phases present in catalysts. Applied to metallic iron catalysts used in the Fischer-Tropsch reaction it reveals a detailed picture of the carburization process and provides insight into the relation between the properties of the catalytic material and its activity. The influence of a support and the effect of alloying iron with an (in)active metal on the catalytic performance is discussed for Fe, CuFe and NiFe systems. In addition, Mössbauer spectroscopy is used for the identification of "Co-sulfide" species present in sulfided Co and CoMo catalysts applied in one of the largest chemical processes in the world, the hydrotreatment of crude oil. A structural model is proposed. Finally, the contribution of Mössbauer spectroscopic studies to the development of a new catalyst for cleaning of Claus tail gas via selective oxidation of hydrogen sulfide to elemental sulfur is discussed.

  8. Technology development for iron Fischer-Tropsch catalysis. Quarterly technical progress report No. 5, October 1, 1995--December 31, 1995

    SciTech Connect

    Davis, B.H.

    1996-01-19

    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 ``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 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. The research is divided into four major topical areas: (a) catalyst preparation and characterization, (b) product characterization, (c) reactor operations, and (d) data assessment. Accomplishments to date are described.

  9. Technology development for iron Fischer-Tropsch catalysis. Quarterly technical progress report No. 6, January 1, 1996--March 31, 1996

    SciTech Connect

    Davis, B.H.

    1996-05-01

    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 ``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. The research is divided into four major topical areas: (a) catalyst preparation and characterization, (b) product characterization, (c) reactor operations, and (d) data assessment. Accomplishments for this period are discussed.

  10. Technology development for iron Fischer-Tropsch catalysis. Quarterly technical progress report No. 7, April 1, 1996--June 30, 1996

    SciTech Connect

    Davis, B.H.

    1996-08-07

    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 ``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 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. The research is divided into four major topical areas: (a) catalyst preparation and characterization, (b) product characterization, (c) reactor operations, and (d) data assessment.

  11. Technology development for iron Fischer-Tropsch catalysis. Quarterly technical progress report No. 3, April 1, 1995--June 30, 1995

    SciTech Connect

    1995-08-18

    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. 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 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. The research is divided into four major topical areas: (a) catalyst preparation and characterization, (b) product characterization, (c) reactor operations, and (d) data assessment.

  12. Selectivity to olefins of Fe/SiO{sub 2}-MgO catalysts in the Fischer-Tropsch reaction

    SciTech Connect

    Gallegos, N.G.; Alvarez, A.M.; Cagnoli, M.V.; Bengoa, J.F.

    1996-06-01

    SiO{sub 2} covered with MgO has been used as support of iron catalysts in the Fischer-Tropsch reaction. Catalysts of 5% (w/w) iron concentration and 2, 4, and 8% (w/w) of MgO on SiO{sub 2} were prepared. Selective chemisorption of CO, volumetric oxidation, and Moessbauer spectroscopy were used to characterize the type of iron species and the metallic crystal sizes. MgO covers the SiO{sub 2} surface and modifies the metallic crystal size. The activity to total hydrocarbons increases with the amount of MgO added. An optimal concentration of about 4% (w/w) was found to have the highest selectivity to olefins. 45 refs., 13 figs., 3 tabs.

  13. Technology development for iron Fischer-Tropsch catalysis. Quarterly technical progress report No. 4, July 1, 1995--September 30, 1995

    SciTech Connect

    Davis, B.H.

    1996-01-09

    The affect of copper promotion on the activity and selectivity of hydrogen pretreated, precipitated iron Fischer-Tropsch catalysts was studied. Fischer-Tropsch synthesis was carried out in the slurry phase in one in one liter continuous stirred tank reactors at a space velocity of 3.lNL h{sup {minus}1} g{sup {minus}1}(Fe), H{sub 2}:CO = 0.7 at either 270{degree}C or 230{degree}C. Catalysts with atomic compositions relative to iron of 10OFe/4.4Si/l.OK and 10OFe/4.4Si/2.6Cu/l.OK were used at 270{degree}C and catalysts with the compositions of 100Fe/4.4Si/4.2K and 10OFe/4.4Si/2.6Cu/4.2K were used at 230{degree}C. XRD and Moessbauer spectroscopy both show that the 10OFe/4.4Si/2.6Cu/l.OK catalyst contained approximately 24% {alpha}-Fe with the remainder Fe{sub 3}O{sub 4} after a 24 h pretreatment with hydrogen at 220{degree}C. Copper promotion was found to substantially increase the activity and productivity of the catalysts. Catalysts promoted with copper reached maximum activity within 100 h of synthesis while catalysts with no copper went through an induction period. The activity of the hydrogen pretreated 10OFe/4.4Si/2.6Cu/1.0K catalyst operated at 270{degree}C was comparable to the activity of the the 100Fe/4.4Si/l.OK catalyst after pretreatment with carbon monoxide or syngas at one atmosphere pressure. However, the activity of the hydrogen pretreated 1O0Fe/4.4Si/2.6Cu/4.2K catalyst at 230{degree}C was found to be substantially lower than the same catalyst pretreated with carbon monoxide or syngas at one atmosphere pressure.

  14. 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.

  15. 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. PMID:27389315

  16. Technology development for iron Fischer-Tropsch catalysts. Technical progress report No. 7, April 1, 1992--June 30, 1992

    SciTech Connect

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

    1992-12-31

    The objective 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 H{sub 2} and 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/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 made on catalyst development.

  17. Technology development for iron Fischer-Tropsch catalysts. Technical progress report No. 6, December 26, 1991--March 31, 1992

    SciTech Connect

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

    1992-12-31

    The objective 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 H{sub 2} and 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/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 made on catalyst development.

  18. Development of a stable cobalt-ruthenium Fischer-Tropsch catalyst. Technical progress report No. 10, January 1, 1992--March 31, 1992

    SciTech Connect

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

    1992-12-31

    In this report, and the three before it, progress has been reviewed toward finding a support for cobalt/ruthenium-based Fischer-Tropsch catalysts. Of the support materials investigated three have so far shown promise: magnesium oxide, carbon and 50/50 alumina/titania. However, as yet catalysts supported on these three materials have proven inferior to the reference TC 211 Y zeolite-supported catalyst with regard to both activity and selectivity. Ruthenium is considered to be a promoter of activity, however, if this effect is manifested in the experimental catalysts it is not enough to make the catalysts more active than the ruthenium-free reference catalyst. The advantages due to reverse micelle are, so far, minimal at best. When the experimental catalysts were operated at higher conversions through evaluation at Conditions 2 and 3, the magnesium oxide-supported catalysts appeared to be closest to the desired low methane selectivity of the reference catalyst at similar conversion. The catalysts prepared on the above supports were not superior to the reference catalyst TC 211. Since the main objective of the current contract is to determine whether cobalt/ruthenium catalysts can be prepared which are superior to cobalt only catalysts, the Y zeolite support will be used in the future. In this special Y zeolite-derived support crystallite size is controlled by the pore size distribution. Thus, the catalyst development objective of controlling the crystallite size will be achieved. In the following quarters, work carried out on the cobalt and cobalt/ruthenium catalysts supported on the Y zeolite-derived support will be reported.

  19. 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.

  20. Technology development for iron Fischer-Tropsch catalysts. Technical progress report No. 10, December 26, 1992--March 26, 1993

    SciTech Connect

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

    1993-12-31

    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 made on Task 1.2 and 2.0.

  1. Technology development for iron Fischer-Tropsch catalysts. Technical progress report No. 8, July 1, 1992--September 30, 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 made on Task 1.

  2. 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. PMID:27433672

  3. 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.

  4. Kinetic model of product distribution over Fe catalyst for Fischer-Tropsch synthesis

    SciTech Connect

    Rongle Zhang; Jie Chang; Yuanyuan Xu; Liren Cao; Yongwang Li; Jinglai Zhou

    2009-09-15

    A new kinetic model of the Fischer-Tropsch synthesis (FTS) is proposed to describe the non-Anderson-Schulz-Flory (ASF) product distribution. The model is based on the double-polymerization monomers hypothesis, in which the surface C{sub 2}{asterisk} species acts as a chain-growth monomer in the light-product range, while C{sub 1}{asterisk} species acts as a chain-growth monomer in the heavy-product range. The detailed kinetic model in the Langmuir-Hinshelwood-Hougen-Watson type based on the elementary reactions is derived for FTS and the water-gas-shift reaction. Kinetic model candidates are evaluated by minimization of multiresponse objective functions with a genetic algorithm approach. The model of hydrocarbon product distribution is consistent with experimental data (

  5. Preparation, surface characterization and performance of a Fischer-Tropsch catalyst of cobalt supported on silica nanosprings

    NASA Astrophysics Data System (ADS)

    Kengne, Blaise-Alexis Fouetio; Alayat, Abdulbaset M.; Luo, Guanqun; McDonald, Armando G.; Brown, Justin; Smotherman, Hayden; McIlroy, David N.

    2015-12-01

    The reduction of cobalt (Co) catalyst supported on silica nanosprings for Fischer-Tropsch synthesis (FTS) has been monitored by X-ray photoelectron spectroscopy (XPS) and compared to FT catalytic activity. The cobalt is present in the starting catalyst as a Co3O4 spinel phase. A two-step reduction of Co3O4 to CoO and then to Co0 is observed, which is consistent with the results of H2-temperature programmed reduction. During the reduction the two steps occur concurrently. The deconvolution of the Co 2p core level state for the catalyst reduced at 385 °C and 1.0 × 10-6 Torr of H2 revealed signatures of Co0, CoO, and Co3O4. The reduction saturates at a Coo concentration of approximately 41% after 20 h, which correlates with the activity and lifetime of the catalyst during FTS testing. Conversely, at 680 °C and 10 Torr of H2, the catalyst is completely reduced after 10 h. The evolution of the Co d-band at the Fermi level in the valence band XPS spectrum definitively verifies the metallic phase of Co. FTS evaluation of the Co/NS catalyst reduced at 609 °C showed higher production rate (3-fold) of C6-C17 hydrocarbons than the catalyst reduced at 409 °C and is consistent with the XPS analysis.

  6. An innovative catalyst system for slurry-phase Fischer-Tropsch synthesis: Cobalt plus a water-gas-shift catalyst. Final technical report

    SciTech Connect

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

    1991-07-01

    The feasibility of using a mechanical mixture of a Co/MgO/SiO{sub 2} Fischer-Tropsch catalyst and a Cu-ZnO/Al{sub 2}O{sub 3} water-gas-shift (WGS) catalyst for hydrocarbon synthesis in a slurry reactor has been established. Such a mixture can combine the superior product distribution from cobalt with the high activity for the WGS reaction characteristic of iron. Weight ratios of Co/MgO/SiO{sub 2} to Cu-ZnO/Al{sub 2}O{sub 3} of 0.27 and 0.51 for the two catalysts were studied at 240{degrees}C, 0.79 MPa, and in situ H{sub 2}/CO ratios between 0.8 and 3.0. Each catalyst mixture showed stable Fischer-Tropsch activity for about 400 hours-on-stream at a level comparable to the cobalt catalyst operating alone. The Cu-ZnO/Al{sub 2}O{sub 3} catalyst exhibited a very slow loss of activity under these conditions, but when operated alone it was stable in a slurry reactor at 200--220{degrees}C, 0.79--1.48 MPa, and H{sub 2}/CO in situ ratios between 1.0 and 2.0. The presence of the water-gas-shift catalyst did not affect the long-term stability of the primary Fischer-Tropsch selectivity, but did increase the extent of secondary reactions, such as l-alkene hydrogenation and isomerization.

  7. Baseline design/economics for advanced Fischer-Tropsch technology. Quarterly report, October--December 1992

    SciTech Connect

    Not Available

    1992-12-31

    Bechtel, with Amoco as the main subcontractor, initiated a study on September 26, 1991, for the US Department of Energy`s (DOE`s) Pittsburgh Energy Technology Center (PETC) to develop a computer model and baseline design for advanced Fischer-Tropsch (F-T) technology. This 24-month study, with an approved budget of $2.3 million, is being performed under DOE Contract Number AC22-91PC90027. (1) Develop a baseline design and two alternative designs for indirect liquefaction using advanced F-T technology. The baseline design uses Illinois No. 6 Eastern Coal and conventional refining. There is an alternative refining case using ZSM-5 treatment of the vapor stream from the slurry F-T reactor and an alternative coal case using Western coal from the Powder River Basin. (2) Prepare the capital and operating costs for the baseline design and the alternatives. Individual plant costs for the alternative cases will be prorated on capacity, wherever possible, from the baseline case. (3) Develop a process flowsheet simulation (PFS) model. The baseline design, the economic analysis and computer model will be major research planning tools that PETC will use to plan, guide and evaluate its ongoing and future research and commercialization programs relating to indirect coal liquefaction for the manufacture of synthetic liquid fuels from coal.

  8. 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.

  9. 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.

  10. An Auger electron spectroscopy study of the activation of iron Fischer-Tropsch catalysts. II. Carbon monoxide activation

    SciTech Connect

    Sault, A.G. ); Datye, A.K. )

    1993-03-01

    Activation procedures can have a dramatic effect on the activity of iron-based catalysts for Fischer-Tropsch (F-T) synthesis. CO conversion over a 100 Fe/3 Cu/0.2 K catalyst (parts by weight) can vary by nearly a factor of 3, depending on activation treatment. In contrast, a 100 Fe/5 Cu/4.2 K/25 SiO[sub 2] catalyst displays little dependence of F-T activity on activation treatment. An ultra-high vacuum surface analysis chamber coupled to an atmospheric reactor has been used to measure the surface composition of these catalysts following activation in carbon monoxide at 280[degrees]C, while transmission electron microscopy (TEM) and BET surface area measurements have been used to investigate catalyst morphology. CO activation of the 100 Fe/5 Cu/4.2 K/25 SiO[sub 2] catalyst at 280[degrees]C results in partial reduction of iron to a mixture of Fe[sub x]O and Fe[sub 3]O[sub 4], and an overall surface composition very similar to that obtained following hydrogen activation at 220 or 280[degrees]C, consistent with the invariance of F-T activity with activation treatment for this catalyst. Activation of the 100 Fe/3 Cu/0.2 K catalyst in CO at 280[degrees]C results in the formation of iron carbide particles, growth of graphitic carbon (C[sub g]) filaments, and formation of a thick, porous, C[sub g] layer covering the carbide particles. Differences in F-T activity between the hydrogen- and CO-activated 100 Fe/3 Cu/0.2 K catalyst are discussed in terms of surface composition and catalyst morphology. The difference in sensitivity of the two catalysts to activation conditions is related to differences in the extent of reduction of the catalysts. 45 refs., 4 figs., 1 tab.

  11. An Auger electron spectroscopy study of the activation of iron Fischer-Tropsch catalysts. I. Hydrogen activation

    SciTech Connect

    Sault, A.G. )

    1993-03-01

    Activation procedures can have a dramatic effect on the activity of iron-based catalysts for Fischer-Tropsch (F-T) synthesis. CO conversion over a 100 Fe/3 Cu/0.2 K catalyst (parts by weight) can vary by nearly a factor of 3, depending on activation. In contrast, a 100 Fe/5 Cu/4.2 K/25 SiO[sub 2] catalyst displays only minor variations in activity with activation conditions. An ultra-high vacuum surface analysis chamber coupled to an atmospheric pressure reactor has been used to measure the surface compositions of these catalysts following various hydrogen activation procedures. Activation of the 100 Fe/3 Cu/0.2 K catalyst in H[sub 2] results in rapid reduction of iron to the metallic state, and segregation of sulfur to the catalyst surface. The sulfur arises from bulk sulfate impurities present in the metal nitrates used to prepare the catalyst. Sulfur coverage increases with both activation time and temperature, due to an increase in the rate of sulfur diffusion with temperature. F-T activity of this catalyst varies inversely with sulfur coverage, consistent with the well-known poisoning effect of sulfur on F-T synthesis. For the 100 Fe/5 Cu/4.2 K/25 SiO[sub 2] catalyst no significant variations in surface composition are observed as a function of hydrogen activation temperature, consistent with the absence of any variations in catalyst activity. Only partial reduction of iron to a mixture of Fe[sub x]O and Fe[sub 3]O[sub 4] is observed for this catalyst for all activation conditions investigated. Using electron beam effects to remove potassium and silica shows that one or both of these components inhibits reduction of iron to the metallic state in the 100 Fe/5 Cu/4.2 K/25 SiO[sub 2] catalyst. 48 refs., 3 tabs.

  12. 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.

  13. Separation of fischer-Tropsch Wax from Catalyst by Supercritical Extraction.

    SciTech Connect

    Joyce, P.C.; Thies, M.C.; Sherrard, D.; Biales, J.; Kilpatrick, P.; Roberts, G.

    1997-07-31

    Although alkanes are the major constituent of a Fischer-Tropsch wax, significant quantities (e.g., up to 30 wt %) of long-chain alcohol and alkene compounds can also be found in a F-T wax. With the lack of experimental data, the effect that the hydroxy and double-bond functional groups have on the phase behavior of systems containing long- chain hydrocarbons is unknown. Therefore, the phase behavior of the system n-hexane/1-hexadecanol was measured for comparison with the previously measured system n-hexane/hexadecane. Vapor and liquid equilibrium compositions and mixture critical points were measured at 198.9, 251.3, 299.2, and 349.9 {degrees}C at pressures ranging from 6.2 to 46.4 bar. Temperature and pressure measurements for all isotherms are believed to be accurate to better than plus or minus 3 and 4 percent, respectively. Results indicate that the addition of the alcohol group to a C 16 hydrocarbon chain significantly affects the phase behavior with hexane, with the two-phase region extending to significantly higher (i.e., up to about 10 bar higher) pressures. The presence of an alcohol group was also found to be an impediment to obtaining a good fit of the experimental data with the Peng-Robinson equation.

  14. Fischer Tropsch synthesis in supercritical fluids. Quarterly technical progress report, April 1, 1995--June 30, 1995

    SciTech Connect

    Akgerman, A.; Bukur, D.B.

    1996-05-01

    Our objective for this quarter was to study the effect of co-feeding a 1-olefin on the Ruhrchemie catalyst activity and selectivity, during-both conventional Fisher-Tropsch synthesis (FTS) and FTS under supercritical conditions. We used propane as the supercritical fluid and 1-dodecene (1-C{sub 12}H{sub 24}) in this test. Motivation for this study was the work of Fujimoto and co-workers who reported that suppression of methane and enhancement of high molecular weight hydrocarbons selectivities occurs with co-feeding of 1-olefins (1-heptene, 1-tetradecene, or 1-hexadecene) during FTS under supercritical conditions, but not during the conventional FTS (Co-La catalyst supported on silica in supercritical n-pentane).The diffusion coefficients of products in supercritical fluids is discussed.

  15. 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.

  16. Fischer Tropsch synthesis in supercritical fluids. Quarterly technical progress report, July 1, 1993--September 30, 1993

    SciTech Connect

    Akgerman, A.; Bukur, D.B.

    1993-12-31

    During this quarter we have tested and calibrated six thermocouples of the temperature probe assembly. We obtained additional information on potential supercritical fluids from several vendors. We found out that all three potential supercritical solvents (propane, butane, and hexane) have less than 1 ppM sulfur impurities, whereas the maximum amount of sulfur in the feed should be less than 0.05 ppM. This remains to be a potential problem, since high levels of sulfur in the feed will result in catalyst poisoning. However, this would be the case with all three potential solvents, and thus we have decided to use propane as the supercritical fluid in our reaction studies based on its cost and favorable supercritical properties. In our shake down tests we will not use a catalyst guard bed for sulfur removal. If we experience problems with catalyst deactivation due to sulfur in feed, the guard bed will be installed in the propane feed line. We have ordered 1-tetradecene and will begin measuring diffusion coefficients of this compound in subcritical propane.

  17. Study of Fischer-Tropsch synthesis over iron-based catalysts using a well-stirred slurry reactor

    SciTech Connect

    Dictor, R.A.

    1984-01-01

    Fischer-Tropsch synthesis over iron catalysts has been researched for well over 60 years, yet relatively few detailed investigations of the kinetics and selectivity of hydrocarbon synthesis have been done using unpromoted bulk iron-based catalysts. In this investigation, Fe/sub 2/O/sub 3/, potassium-promoted Fe/sub 2/O/sub 3/, fused iron, Fe/sub 3/C, and Fe were tested for their activity and selectivity for hydrocarbon synthesis, and comparisons were made between the catalysts. Experiments were done using a well-stirred slurry reaction which was free of temperature and concentration gradients. The effluent from the reactor was analyzed on line using a dual-column gas chromatograph. The compositions of fresh and used catalyst samples were determined using X-ray diffraction. The activity of fused iron catalyst increases with extent of reduction in H/sub 2/ - attributed to increases in surface area. Principal products are normal 1-olefins and paraffins, CO/sub 2/, H/sub 2/O; branched olefins, aldehydes and alcohols are also formed. The catalyst has very little hydrogenation or isomerization activity due to potassium promotion. Aldehydes reduce to alcohols; the water-gas-shift reaction occurs. The kinetics and selectivity observed using potassium-promoted Fe/sub 2/O/sub 3/ were nearly identical to those of fused iron. In the absence of promoter, the products are almost exclusively n-olefins, n-paraffins, CH/sub 3/OH, H/sub 2/O, CO/sub 2/. Fe/sub 2/O/sub 3/ is active for hydrogenation and isomerization.

  18. Study of the carburization of an iron catalyst during the Fischer-Tropsch synthesis: influence on its catalytic activity

    SciTech Connect

    Pijolat, M.; Perrichon, V.; Bussiere, P.

    1987-09-01

    The fast transformation of an ironalumina catalyst into Fe/sub 2+x/C during the H/sub 2/ + CO reaction was followed by in situ Moessbauer spectroscopy at 523 K and the behavior was compared with changes in catalytic activity for Fischer-Tropsch synthesis. After a few hours of synthesis, no metallic iron could be detected by either Moessbauer or IR spectroscopy, whereas the CO conversion was still half of that observed initially. The nature of the sites responsible for the remaining activity is discussed. The interpretation of the Moessbauer spectra has permitted the determination of the stoichiometry of the Fe/sub 2+x/C carbide (0 less than or equal to x less than or equal to 0.4), and hence the following of the change of x during the reaction. Thus, the activity in CO hydrogenation could be related to the number of carbon vacancies in the iron carbide, i.e., to the extent of the metallic character of this carbide. This concept of the variation of hydrogenating properties of the carbide with the carbon content has been supported by similar catalytic results obtained in the room temperature hydrogenation of ethylene performed on carbides of different stoichiometry

  19. The effect of Mg location on Co-Mg-Ru/γ-Al2O3 Fischer-Tropsch catalysts.

    PubMed

    Gallagher, James R; Boldrin, Paul; Combes, Gary B; Ozkaya, Don; Enache, Dan I; Ellis, Peter R; Kelly, Gordon; Claridge, John B; Rosseinsky, Matthew J

    2016-02-28

    The effectiveness of Mg as a promoter of Co-Ru/γ-Al2O3 Fischer-Tropsch catalysts depends on how and when the Mg is added. When the Mg is impregnated into the support before the Co and Ru addition, some Mg is incorporated into the support in the form of MgxAl2O3+x if the material is calcined at 550°C or 800°C after the impregnation, while the remainder is present as amorphous MgO/MgCO3 phases. After subsequent Co-Ru impregnation MgxCo3-xO4 is formed which decomposes on reduction, leading to Co(0) particles intimately mixed with Mg, as shown by high-resolution transmission electron microscopy. The process of impregnating Co into an Mg-modified support results in dissolution of the amorphous Mg, and it is this Mg which is then incorporated into MgxCo3-xO4. Acid washing or higher temperature calcination after Mg impregnation can remove most of this amorphous Mg, resulting in lower values of x in MgxCo3-xO4. Catalytic testing of these materials reveals that Mg incorporation into the Co oxide phase is severely detrimental to the site-time yield, while Mg incorporation into the support may provide some enhancement of activity at high temperature. PMID:26755760

  20. Fischer-Tropsch Performance of an SiO2-Supported Co-Based Catalyst Prepared by Hydrogen Dielectric-Barrier Discharge Plasma

    NASA Astrophysics Data System (ADS)

    Fu, Tingjun; Huang, Chengdu; Lv, Jing; Li, Zhenhua

    2014-03-01

    A silica-supported cobalt catalyst was prepared by hydrogen dielectric-barrier discharge (H2-DBD) plasma. Compared to thermal hydrogen reduction, H2-DBD plasma treatment can not only fully decompose the cobalt precursor but also partially reduce the cobalt oxides at lower temperature and with less time. The effect of the discharge atmosphere on the property of the plasma-prepared catalyst and the Fischer-Tropsch synthesis activity was studied. The results indicate that H2-DBD plasma treatment is a promising alternative for preparing Co/SiO2 catalysts from the viewpoint of energy savings and efficiency.

  1. Fischer-Tropsch synthesis: kinetics and effect of water for a Co/SiO{sub 2} catalyst

    SciTech Connect

    Tapan K. Das; Whitney A. Conner; Jinlin Li; Gary Jacobs; Mark E. Dry; Burtron H. Davis

    2005-08-01

    The addition of water during Fischer-Tropsch synthesis over a 12.4 wt% Co/SiO{sub 2} catalyst led to a significant increase in CO conversion. A positive reversible impact of water on catalyst activity was observed at partial pressures of water of {lt}25 vol% added H{sub 2}O. The CO conversion recovered to the reference activity after the termination of water addition. Therefore, this enhanced reversible activity for Co/SiO{sub 2} catalysts seems to be due to a kinetic effect of water. The catalyst was characterized using different techniques, including temperature-programmed reduction (TPR), Brunauer-Emmett-Teller (BET) surface area analysis, and H{sub 2} chemisorption. The rate expression has been obtained over the catalyst, using a 1-L continuously stirred tank reactor (CSTR) that was operated at a temperature of 483 K, a pressure of 2.21 MPa (21.42 atm), H{sub 2}/CO feed ratios of 1.0-2.4, and 10%-70% CO conversion over a range of reactant partial pressures. The data of this study are fitted by a power-law expression of the form r{sub CO} = kP{sub CO}{sup -0.25}P{sub H{sub 2}}{sup -.5}/(1 + mP{sub H{sub 2}O}/P{sub H{sub 2}), where k = 0.89 mol h{sup -1} g{sub cat}{sup -1} and m = -0.155. 41 refs., 13 figs., 8 tabs.

  2. Fischer-Tropsch slurry phase process variations. Quarterly report, January 1, 1986-March 31, 1986

    SciTech Connect

    Satterfield, C.N.; Hanlon, R.; Matsumoto, D.K.

    1986-01-01

    Two principal experiments were conducted, in which synthesis activity, selectivity, and the bulk catalyst composition were monitored for approximately the initial 200 hours on stream. One was performed at 248/sup 0/C (run Fe22) and one at 232/sup 0/C (run Fe27), with an intermediate period at 263/sup 0/C. A third experiment (run Fe24) was conducted at 248/sup 0/C for 22 hours to verify the reproducibility of the initial activity and selectivity results of run Fe22, but no catalyst samples were taken. Four phases of iron were identified in the catalyst, namely ..cap alpha..-Fe, magnetite (Fe/sub 3/O/sub 4/), and two forms of iron carbide. The Moessbauer parameters of these phases agree well with data in the literature of the Quarterly Report for October-December 1985. Some significant observations are as follows: First, the methane selectivity was high for the earlier times on stream, (32 mole% methane) for 0 to 7 hours on stream as compared to 27 mole% for 7 to 22 and 22 to 34 hours on stream. Second, the C/sub 2/-C/sub 7/ product distributions were quite similar for the three time intervals. The value of ..cap alpha.., as determined by the slope of the distribution of the C/sub 3/-C/sub 7/ products, increased only slightly over time, from a value of 0.62 from 0 to 7 hours to a value of 0.64 from 7 to 22 and 22 to 34 hours. Finally, the C/sub 8/-C/sub 14/ fraction increased significantly with time, reflecting the effect of the accumulation and eventual saturation of heavier hydrocarbon products in the reactor. 9 figs. 7

  3. 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

    2006-03-03

    Efforts during this second year focused on four areas: (1) continued searching and summarizing of published Fischer-Tropsch synthesis (FTS) mechanistic and kinetic studies of FTS reactions on iron catalysts; (2) investigation of CO adsorption/desorption and temperature programmed hydrogenation (TPH) of carbonaceous species after FTS on unsupported iron and alumina-supported iron catalysts; (3) activity tests of alumina-supported iron catalysts in a fixed bed reactor; (4) sequential design of experiments, for the collection of rate data in a Berty CSTR reactor, and nonlinear-regression analysis to obtain kinetic parameters. Literature sources describing mechanistic and kinetic studies of Fischer-Tropsch synthesis on iron catalysts were compiled in a review. Temperature-programmed desorption/reaction methods (the latter using mass-spectrometry detection and also thermogravimetric analyzer (TGA)) were utilized to study CO adsorption/-desorption on supported and unsupported iron catalysts. Molecular and dissociative adsorptions of CO occur on iron catalysts at 25-150 C. The amounts adsorbed and bond strengths of adsorption are influenced by supports and promoters. That CO adsorbs dissociatively on polycrystalline Fe at temperatures well below those of FT reaction indicates that CO dissociation is facile and unlikely to be the rate-limiting step during FTS. Carbonaceous species formed after FT reaction for only 5 minutes at 200 C were initially hydrogenated under mild, isothermal condition (200 C and 1 atm), followed by TPH to 800 C. During the mild, isothermal hydrogenation, only about 0.1-0.2 mL of atomic carbon is apparently removed, while during TPH to 800 C multilayer equivalents of atomic, polymeric, carbidic, and graphitic carbons are removed. Rates of CO conversion on alumina-supported iron catalysts at 220-260 C and 20 atm are correlated well by a Langmuir-Hinshelwood expression, derived assuming carbon hydrogenation to CH and OH recombination to water to be

  4. 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

  5. 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). PMID:24460136

  6. Kinetically Relevant Steps and H2/D2 Isotope Effects in Fischer-Tropsch Synthesis on Fe and Co Catalysts

    SciTech Connect

    Ojeda, Manuel; Li, Anwu; Nabar, Rahul P.; Nilekar, Anand U.; Mavrikakis, Manos; Iglesia, Enrique

    2010-11-25

    H2/D2 isotope effects on Fischer-Tropsch synthesis (FTS) rate and selectivity are examined here by combining measured values on Fe and Co at conditions leading to high C5+ yields with theoretical estimates on model Fe(110) and Co(0001) surfaces with high coverages of chemisorbed CO (CO*). Inverse isotope effects (rH/rD < 1) are observed on Co and Fe catalysts as a result of compensating thermodynamic (H2 dissociation to H*; H* addition to CO* species to form HCO*) and kinetic (H* reaction with HCO*) isotope effects. These isotopic effects and their rigorous mechanistic interpretation confirm the prevalence of H-assisted CO dissociation routes on both Fe and Co catalysts, instead of unassisted pathways that would lead to similar rates with H2 and D2 reactants. The small contributions from unassisted pathways to CO conversion rates on Fe are indeed independent of the dihydrogen isotope, as is also the case for the rates of primary reactions that form CO2 as the sole oxygen rejection route in unassisted CO dissociation paths. Isotopic effects on the selectivity to C5+ and CH4 products are small, and D2 leads to a more paraffinic product than does H2, apparently because it leads to preference for chain termination via hydrogen addition over abstraction. These results are consistent with FTS pathways limited by H-assisted CO dissociation on both Fe and Co and illustrate the importance of thermodynamic contributions to inverse isotope effects for reactions involving quasi-equilibrated H2 dissociation and the subsequent addition of H* in hydrogenation catalysis, as illustrated here by theory and experiment for the specific case of CO hydrogenation.

  7. 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

  8. Application of a novel TPR EXAFS/XANES method using a multi-sample holder to characterize promoted iron and cobalt fFischer-Tropsch synthesis catalysts.

    SciTech Connect

    Jacobs, G.; Sarkar, A.; Ji, Y.; Davis, B. H.; Cronauer, D.; Kropf, A. J.; Marshall, C. L.; Chemical Sciences and Engineering Division; Univ. of Kentucky

    2008-01-01

    Coal-to-liquids. Iron-based Fischer-Tropsch synthesis catalysts are not only used commercially for high temperature Fischer-Tropsch synthesis, but are increasingly becoming the focus for converting low H{sub 2}/CO ratio synthesis gas at lower temperature. Such low temperature processing yields hydrocarbon distributions with higher {alpha} values, and as a consequence, much less light hydrocarbon gas production (and especially, less methane). Another benefit to the use of iron-based catalysts is that the product slate is richer in {alpha}-olefinic products, which are more valuable than the paraffinic products produced using cobalt-based catalysts. Iron-based catalysts are often used to convert low H{sub 2}/CO ratio syngas, because the catalysts can intrinsically adjust the syngas ratio upward by converting a fraction of CO by reaction with H{sub 2}O to produce H{sub 2} and CO{sub 2} via the water-gas shift reaction.

  9. Iron oxide pillared clay with large gallery height: Synthesis and properties as a Fischer-Tropsch catalyst

    SciTech Connect

    Rightor, E.G.; Tsou, Mingshin; Pinnavaia, T.J. )

    1991-07-01

    New iron oxide pillared montmorillonites have been prepared by the reaction of Na{sup +} montmorillonite with base-hydrolyzed solutions of Fe{sup 3+} salts and subsequent thermal conversion of the intercalated polycations. Depending on the hydrolysis conditions used to generate the pillaring solutions, pillared products with basal spacings in the range 18 to 25 {angstrom} were obtained. Under optimum hydrolysis conditions (base/metal = 2.0 meq/mol, aging time = 23-147 hr) the pillared products contained 6.8-9.8 Fe{sup 3+} ions per O{sub 20}(OH){sub 4} unit cell and exhibited basal spacings of 25-29 {angstrom}. These latter spacings corresponded to exceptionally large gallery heights of 15-19 {angstrom}. Upon calcination at 300C, the spacings decreased to 23-27 {angstrom}. N{sub 2} BET surface areas after outgassing at 350C were in the range 270 to 350 m{sup 2}/g. The pillared products are active catalysts that have undergone Fischer-Tropsch synthesis of hydrocarbons at 275 C and 120 {minus}psi (CO:H{sub 2}=1:2). The hydrocarbon distribution in the C{sub 1}-C{sub 6} range (1.3% conversion) followed Anderson-Schulz-Flory statistics with a chain propagation probability of {alpha} = 0.49. X-ray energy dispersive analysis indicated that substantial amounts of the intercalated iron migrated to the edge sites of the clay particles under reaction conditions. The redistribution of iron resulted in a distribution of gallery heights sufficiently heterogeneous to preclude Bragg X-ray scattering along the 001 direction. Iron migration also occurred upon exposure of the pillared products to the ambient atmosphere for prolonged periods ({ge}3 months).

  10. Fischer-Tropsch slurry phase process variations to understand wax formations: Quarterly report for period October 1, 1987 to December 31, 1987

    SciTech Connect

    Satterfield, C.N.

    1987-01-01

    Effects of high syngas conversion on the secondary reactions of olefins formed by Fischer-Tropsch synthesis on a reduced fused magnetite catalyst were simulated by studies of olefins in the presence of hydrogen and low concentrations of CO, or none at all. kinetic models were developed for the effect of CO partial pressure on hydrogenation rates at 232)degree)C and 0.30 to 0.79 MPa. In the absence of carbon monoxide, olefin hydrogenation was more rapid than in its presence. A model indicated that a hydrogenated carbon monoxide species on the catalyst may be responsible for the inhibition of olefin hydrogenation, and that olefin adsorption is rate-limiting. The formation of secondary olefins appeared to follow similar trends with carbon monoxide partial pressure. Olefin incorporation was not observed in the small amount of Fischer-Tropsch products obtained in these experiments. The chain growth probability, alpha, appeared to correlate with the H/sub 2/CO feed ratio. 14 refs., 13 figs., 1 tab.

  11. 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

  12. Fischer-Tropsch synthesis in slurry reactor systems. Quarterly report, May 1, 1984-July 31, 1984

    SciTech Connect

    Satterfield, C.N.; Bartos, T.; Hanlon, R.; Huff, G.A. Jr.; Matsumoto, D.

    1984-01-01

    We suspect that a number of reports in the published literature of catalyst preparations that supposedly minimize wax formation are erroneous in that wax may actually have accumulated in catalyst pores and that insufficient time may have been allowed for the effluent to represent true intrinsic kinetics. Mathematical simulations show the effect of pressure, temperature, rate constant, feed composition, space velocity and Flory parameter ..cap alpha.., on time required for pores to fill, upon liquid product distribution and vapor composition leaving the reactor. The pore filling rate and condensed product composition vary with position through the reactor but not with time. The maximum filling rate does not occur at the same position in the bed as the maximum synthesis rate. For reaction conditions of industrial interest, the greatest effect is caused by the assumed carbon number distribution of the products. A rigorous parameter to generalize the results is not immediately evident. We reported studies of the effect of the nature of the liquid on the activity and selectivity of a reduced fused magnetite catalyst. For interpretation of such studies it is necessary to have data on solubilities of hydrogen and carbon monoxide in the liquids of interest. New data at elevated temperatures and pressure are reported for octacosane, phenanthreene and Fomblin, a perfluorinated polyether, and compared to previous literature on a variety of liquids. When hydrogen solubilities are reported on a volumetric basis, substances of a similar chemical nature have very similar solubilities.

  13. Self-healing catalysts: Co(3)O(4) nanorods for Fischer-Tropsch synthesis.

    PubMed

    Wen, Cun; Dunbar, Darrius; Zhang, Xin; Lauterbach, Jochen; Hattrick-Simpers, Jason

    2014-05-01

    We combine kinetic and spectroscopic data to demonstrate the concept of a self-healing catalyst, which effectively eliminates the need for catalyst regeneration. The observed self-healing is triggered by controlling the crystallographic orientation at the catalyst surface. PMID:24668124

  14. Cobalt catalysts for the conversion of methanol to hydrocarbons and for Fischer-Tropsch Synthesis

    SciTech Connect

    Mauldin, C.H.

    1986-02-04

    This patent describes a catalyst useful for the conversion at reaction conditions of methanol or synthesis gas to hydrocarbons by contact with a catalyst. The catalyst cobalt and thorium in catalytically active amounts, and rhenium, composited with an inorganic oxide support in weight ratio of rhenium:cobalt ranging from about 0.025:1 to about 0.10:1.

  15. Fischer Tropsch synthesis in supercritical fluids. Quarterly technical progress report, October 1--December 31, 1995

    SciTech Connect

    Akgerman, A.; Bukur, D.B.

    1996-06-01

    Objectives for this quarter were to attempt to develop a model to predict the molecular diffusion coefficients to a high degree of accuracy so the authors may be able to predict both the molecular diffusion coefficient and thus the effective diffusivity a priori. They are working on a semi-empirical equation based on the rough hard sphere theory to predict diffusion coefficients in supercritical fluids. In addition, they planned to take additional data in order to extend the database available for development of the predictive equation. The paper discusses accomplishments and problems related to the diffusion coefficients of F-T products in supercritical fluids. Data are presented on the diffusion coefficients of 1-octene in ethane, propane, and hexane.

  16. 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

  17. 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*. PMID:24123803

  18. 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.

  19. Baseline design/economics for advanced Fischer-Tropsch technology. Quarterly report, July--September 1994

    SciTech Connect

    1994-12-31

    This report is Bechtel`s twelfth quarterly technical progress report and covers the period of July through September, 1994. All major tasks associated with the contract study have essentially been completed. Effort is under way in preparing various topical reports for publication. The objectives of this study are to: Develop a baseline design and two alternative designs for indirect liquefaction using advanced F-T technology. The baseline design uses Illinois No. 6 Eastern Coal and conventional refining. There is an alternative refining case using ZSM-5 treatment of the vapor stream from the slurry F-T reactor and an alternative coal case using Western coal from the Powder River Basin. Prepare the capital and operating costs for the baseline design and the alternatives. Individual plant costs for the alternative cases win be prorated on capacity, wherever possible, from the baseline case. Develop a process flowsheet simulation (PFS) model; establish the baseline design and alternatives; evaluate baseline and alternative economics; develop engineering design criteria; develop a process flowsheet simulation (PFS) model; perform sensitivity studies using the PFS model; document the PFS model and develop a DOE training session on its use; and perform project management, technical coordination and other miscellaneous support functions. Tasks 1, 2, 3 and 5 have essentially been completed. Effort is under way in preparing topical reports for publication. During the current reporting period, work progressed on Tasks 4, 6 and 7. This report covers work done during this period and consists of four sections: Introduction and Summary; Task 4 - Process Flowsheet Simulation (PFS) Model and Conversion to ASPEN PLUS; Task 6 - Document the PFS model and develop a DOE training session on its use; and Project Management and Staffing Report.

  20. Effect of H{sub 2}/CO ratio on Fischer-Tropsch synthesis in a slurry reactor with cobalt-based catalyst

    SciTech Connect

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

    1995-12-31

    The effect of syngas having different H{sub 2}/CO ratios on Fischer-Tropsch synthesis in a slurry bubble column reactor with a Cobalt-based catalyst was assessed using a simple reactor model. The data and catalyst used in this model were from Bechtel studies (1990). It was found that hydrogen is likely to become the rate limiting reactant, even at relatively low catalyst activities, not because of gas-liquid mass transfer, but due to the depletion of hydrogen in the gas phase. This will reduce the H{sub 2}/CO ratio in the liquid phase which will consequently decrease the reaction rate and affect the product selectivity. The increase of catalyst concentration appeared not to affect the reactor performance, when using a syngas with low H{sub 2}/CO ratios.

  1. The Effect of Cobalt Loading on Fischer Tropsch Synthesis Over Silicon Carbide Supported Catalyst.

    PubMed

    Lee, Jae Suk; Jung, Jae Sun; Moon, Dong Ju

    2015-01-01

    A series of Co (5-30 wt%) based SiC supported catalysts were prepared by impregnation method and investigated for FTS reaction. The FTS reaction was carried out in a fixed bed reactor system with the H2/CO molar ratio of 2, reaction temperature of 230 degrees C and reaction pressure of 20 bar for 120 h. All catalysts were characterized by N2 physisorption, XRD, TPR, SEM and TEM techniques. It was found that 15 wt% Co/SiC catalyst showed better catalytic performance with high selectivity of C(5+) hydrocarbons than the other catalysts. The results, suggest that the catalytic performance of the catalysts depends on average pore size of support and surface density of cobalt, metal and support interactions. PMID:26328368

  2. Moessbauer spectroscopy study of iron-based catalysts used in Fischer-Tropsch synthesis

    SciTech Connect

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

    1995-12-01

    Mossbauer investigations of iron-based catalysts containing the promoters K, and Cu, and binders consisting of oxides of Al, Si and Zr were carried out. Catalysts subjected to pretreatment in gas atmospheres containing mixtures of CO, H{sub 2}, and He have been studied. It is shown that the nature of binders, promoters and pretreatment of a catalyst influence the iron-phases formed during pretreatment and FT synthesis. Activation of the catalysts in CO leads to rapid and almost complete formation of {chi}-Fe{sub 5}C{sub 2} during activation and gives rise to high (H{sub 2}+CO) conversion. On the other hand, activation of the catalysts in synthesis gas leads to slow and incomplete formation of carbides and low (H{sub 2}+CO) conversion.

  3. 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.

  4. Studies on nanosized iron based modified catalyst for Fischer-Tropsch synthesis application.

    PubMed

    Park, MoonJu; Kang, Jung Shik; Na, Ki Poong; Lee, Sang Deuk; Awate, S V; Moon, Dong Ju

    2011-02-01

    To improve catalytic performance iron based catalyst, the effects of some metal promoters, especially potassium, copper and other transition metal oxides as well as different supports have been reported. A series of Fe/K/Cu catalysts promoted with magnesium and ceria by precipitation method, followed by impregnation method; keeping Cu and K content same. The catalysts were characterized by XRD, N2 physisorption, TPR and TEM techniques. From XRD, the presence of hematite (Fe2O3) phase was detected in all precipitated iron catalysts and CFe2.5 phase in all used catalysts. TPR results showed that addition of Mg facilitated the reduction of Fe2O3 and decrease in reduction temperature. The catalytic performance was investigated in a fixed-bed reactor at 250 degrees C, 2 MPa pressure and H2/CO molar ratio of 2. Concentration of Mg was found to affect the CO conversion and product distribution. It was found that precipitated iron catalyst Fe/Mg/Cu/K with Mg/Fe ratio of 0.1 showed highest conversion (60.6%) and C5(+) selectivity (92.4%) among all catalysts tested. PMID:21456209

  5. Iron Fischer-Tropsch catalysis: Properties of an ultrafine iron oxide catalyst

    SciTech Connect

    Xu, Liguang; Bao, Shiqi; O'Brien, R.; Houpt, D.; Davis, B.H.

    1992-01-01

    A commercial Fe oxide with a particle size of 3 nm is now available. The FT requires considerable time on stream before steady state conditions are attained. Since it is desirable to obtain FT data for the smaller ultrafine Fe oxide catalysts at larger times on steam, data for operation up to 6 months were collected using slurry phase. Results show that the ultrafine Fe oxide maintain catalytic activity for a 150-day operating period. Addition of 0.5% K increased the activity; after 56 days, the activity had declined to and below that of unpromoted catalyst. Neither the unpromoted nor K-promoted catalyst exhibited good selectivity for alkenes.

  6. Fischer-Tropsch synthesis with Fe/Cu/La/SiO2 nano-structured catalyst.

    PubMed

    Pour, Ali Nakhaei; Taghipoor, Sohrab; Shekarriz, Marzieh; Shahri, Seyed Mehdi Kamali; Zamani, Yahya

    2009-07-01

    Nano-structure Fe2O3, CuO and La2O3 components were prepared by micro-emulsion method and then Fe/Cu/La/SiO2 nano-structure catalyst was prepared by mixing and re-slurring the mixture by tetraethylorthosilicate (TEOS). The catalyst composition was designated in term of the atomic ration as: 100Fe/5.64Cu/0.1La/19Si. Structural characterization of nano-structured Fe2O3, CuO and La2O3 components was performed by Transmission Electron Microscopy (TEM), powder X-ray diffraction, Temperature Programmed Reduction (TPR) techniques. Particle size for obtained components was about 20, 21.6 and 12.6 nm for Fe2O3, CuO and La2O3 respectively determined by using XRD pattern (Scherrer equation) and TEM images. Catalytic activity and product selectivity were conducted in a fixed-bed stainless steel reactor and compared with conventional iron catalyst. The results reveal that reducing particle size of catalyst increased the catalyst performance. Also, olefin/paraffin ratios decreased in comparison with conventional catalyst. PMID:19916468

  7. Cobalt catalysts for the conversion of methanol and for Fischer-tropsch synthesis to produce hydrocarbons

    SciTech Connect

    Mauldin, C.H.; Davis, S.M.; Arcuri, K.B.

    1987-05-05

    A regeneration stable catalyst is described for the conversion at reaction conditions of methanol or synthesis gas to liquid hydrocarbons which consists essentially of from about 2 percent to about 25 percent cobalt, based on the weight of the catalyst composition, composited with titania, or a titania-containing support, to which is added sufficient of a zirconium, hafnium, cerium, or uranium promoter to provide a weight ratio of the zirconium, hafnium, cerium, or uranium metal:cobalt greater than about 0.101:1.

  8. Improved cobalt catalysts, and use thereof for Fischer-Tropsch synthesis

    SciTech Connect

    Mauldin, C.H.

    1987-06-02

    This patent describes a process useful for the conversion of synthesis gas feed comprised of hydrogen and carbon monoxide to hydrocarbons. The process comprises contacting the feed at reaction conditions with a catalyst which comprises cobalt, or cobalt and thoria in catalytically active amount composited with tatania or titania-containing support, to which is added sufficient rhenium to obtain, with a similar feed at corresponding process conditions, improved activity, as contrasted with a catalyst composition otherwise similar except that it does not contain rhenium.

  9. 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.

  10. In-situ Moessbauer Spectroscopy of Supported Iron Fischer-Tropsch Catalysts During Activation

    SciTech Connect

    Motjope, Thato R.; Dlamini, Thulani H.

    2005-04-26

    The behavior of Fe based catalysts supported on ZrO2, SiO2, {gamma}-Al2O3, CeO2 and TiO2 during calcination, reduction and FT synthesis have been studied via in situ Moessbauer spectroscopy. It was found that the type of metal support interaction i.e. surface migration or bulk diffusion during calcination was dependant on the type of support used. Surface migration of Fe3+ during calcination was dominant for ZrO2, CeO2 and {gamma}-Al2O3 and this resulted in the sintering of {alpha}-Fe2O3 crystallites. Whereas bulk diffusion was observed mainly for the catalysts prepared using SiO2 and TiO2, causing a stabilization of the small crystallites of Fe3+ that interacted strongly with the support. Upon reduction, the large crystallites of {alpha}-Fe2O3 were found to reduce readily compared to the small crystallites of Fe3+, except for the catalyst prepared using {gamma}-Al2O3, as a support, where the presence of Al3+ resulted in the formation of spinel like species with the formula (Fe{sup 3+}{sub 2-x}Al{sup 3+}{sub x}Fe{sup 2+})O{sub 4} which are resistant to reduction. Upon exposure to synthesis gas, it was found that catalysts supported on ZrO2 and CeO2 carburized readily resulting in the formation of circa 80% {chi}-Fe2.5C. From this study it was observed that {gamma}-Al2O3 is not the preferred support for Fe based FT catalysts, as it forms the least amount of Fe carbides during FT synthesis.

  11. Diffusivities of synthesis gas and Fischer-Tropsch products in slurry media. Quarterly report, September-December 1984

    SciTech Connect

    Akgerman, A.

    1985-01-01

    The goal of this research is to develop a fast and accurate method for measuring liquid diffusion coefficients for the Fischer-Tropsch system at temperatures from ambient to 573 K and pressures from ambient to 7 MPa. The Taylor dispersion technique will be utilized for measuring the diffusivities of carbon monoxide, hydrogen, heptane, octane, nonane, decane, and decanol in molten Fischer-Tropsch wax. The theoretical criteria for measuring diffusivities by the Taylor dispersion method have been given. In addition, the practical departures from an ideal experiment have been discussed; correction for the non-ideal conditions are found in Appendix B (Alizadeh et al., 1980). The effect of varying viscosity on secondary flow effects has been pointed out; it appears that under typical laboratory space limitations, using commercially available tubing, and with diffusivities on the order of 10/sup -9/ m/sup 2//s, it will not be possible to completely eliminate these effects. An apparatus for measuring diffusivity at high temperatures and pressures, where data has heretofore been scarce, is presented. With this apparatus rapid measurements may be made, and with the aid of computer control the measurements may be repeated and large volumes of data generated with minimum requirements of the operator. We anticipate our accuracy being between 0.5 and 4%. 20 references, 4 figures.

  12. Stability and reactivity of ϵ-χ-θ iron carbide catalyst phases in Fischer-Tropsch synthesis: controlling μ(C).

    PubMed

    de Smit, Emiel; Cinquini, Fabrizio; Beale, Andrew M; Safonova, Olga V; van Beek, Wouter; Sautet, Philippe; Weckhuysen, Bert M

    2010-10-27

    The stability and reactivity of ϵ, χ, and θ iron carbide phases in Fischer-Tropsch synthesis (FTS) catalysts as a function of relevant reaction conditions was investigated by a synergistic combination of experimental and theoretical methods. Combined in situ X-ray Absorption Fine Structure Spectroscopy/X-ray Diffraction/Raman Spectroscopy was applied to study Fe-based catalysts during pretreatment and, for the first time, at relevant high pressure Fischer-Tropsch synthesis conditions, while Density Functional Theory calculations formed a fundamental basis for understanding the influence of pretreatment and FTS conditions on the formation of bulk iron carbide phases. By combining theory and experiment, it was found that the formation of θ-Fe(3)C, χ-Fe(5)C(2), and ϵ-carbides can be explained by their relative thermodynamic stability as imposed by gas phase composition and temperature. Furthermore, it was shown that a significant part of the Fe phases was present as amorphous carbide phases during high pressure FTS, sometimes in an equivalent amount to the crystalline iron carbide fraction. A catalyst containing mainly crystalline χ-Fe(5)C(2) was highly susceptible to oxidation during FTS conditions, while a catalyst containing θ-Fe(3)C and amorphous carbide phases showed a lower activity and selectivity, mainly due to the buildup of carbonaceous deposits on the catalyst surface, suggesting that amorphous phases and the resulting textural properties play an important role in determining final catalyst performance. The findings further uncovered the thermodynamic and kinetic factors inducing the ϵ-χ-θ carbide transformation as a function of the carbon chemical potential μ(C). PMID:20925335

  13. Physical, chemical, and catalytic properties of borided cobalt Fischer-Tropsch catalysts

    SciTech Connect

    Wang, J.

    1987-01-01

    Unsupported and alumina-supported borided cobalt catalysts were prepared by chemical reduction of anhydrous cobalt acetate at 25/sup 0/C using B/sub 2/H/sub 6//THF or NaBH/sub 4//diglyme solution as the reducing agent. These catalysts were further activated in H/sub 2/ at 250/sup 0/C prior to use. The physical and chemical properties of these catalysts were characterized by chemical analysis, BET surface area measurements, H/sub 2/ and CO adsorption measurements, X-ray Diffraction, and Temperature Programmed Desorption of CO. The catalytic properties of these catalysts for hydrogenation of CO to hydrocarbons were investigated at 160 - 300/sup 0/C, 1 and 10 atm, and H/sub 2//CO ratio of 2 in a differential conversion range of less than 8%. The data show that unsupported, Na-free, borided cobalt is much more active than Na-containing borided cobalt and pure cobalt on a site basis. Similarly, CoB/Al/sub 2/O/sub 3/ is more than an order of magnitude more active than Co/Al/sub 2/O/sub 3/ is more than an order of magnitude more active than Co/Al/sub 2/O/sub 3/ but has similar selectivity; its selectivity for C/sub 5//sup +/ hydrocarbons, however, is very high (> 75 wt%) at low reaction temperatures (e.g. 170/sup 0/C) or at low H/sub 2//CO ratios (e.g. less than or equal to 1). The observed changes in catalytic and adsorption behavior are consistent with an electron-donor model in which boron atoms donate electrons to cobalt. Na was found to lower catalytic activity of cobalt while increasing selectivity for light hydrocarbons, olefins, and CO/sub 2/ products.

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

    SciTech Connect

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

    1990-01-01

    Experiments on cobalt-catalyzed reactions of light 1-alkenes added to synthesis gas were performed. Data have been collected at 220C, 0.45 to 1.48 MPa and a synthesis gas flow rate between 0.015 and 0.030 Nl/(gcat[center dot]min) with H[sub 2]/CO of 1.45 to 2.25. Ethylene, propene, and butene were added to synthesis gas feed from 0.5 to 1.2 mole% of total feed. For each material balance in which 1-alkenes were added, a material balance was performed at similar process conditions without 1-alkenes added, as base case''. Material balances without added 1-alkenes were also repeated to verify of catalyst selectivity stability. 49 material balances were performed during a single run lasting over 2,500 hours-on-stream. The hydrocarbon data have been completely analyzed; data correlations are still being made. Since C[sub 3]/C[sub 1] ratios by ethene addition, C[sub 4]/C[sub 1] ratios by propene addition, and C[sub 5]/C[sub 1] ratios by 1-butene addition, it appears that 1-alkenes may incorporate into growing chains on the surface of the catalyst. Further evidence for incorporation can be seen by comparing selectivity to n-alcohol one carbon number higher than added 1-alkene. Yield of this n-alcohol increases when alkenes are present. Sensitivity of hydrocarbon distribution to process variables seems to be greater on Co than on Fe catalysts.

  15. Titania-supported catalysts and their preparation for use in Fischer-Tropsch synthesis

    SciTech Connect

    Mauldin, C.H.; Riley, K.L.

    1991-02-12

    This patent describes a support composition for forming a catalyst useful for the conversion of synthesis gas to hydrocarbons. It comprises: titania in which there is incorporated from 0.1 to about 20 wt% of an inorganic oxide binder selected from the group consisting of alumina and zirconia based on the weight of the titania-binder support, to provide a titania-binder support having a pore volume ranging from about 0.2 cc/g to about 0.5 cc/g, and surface area ranging from about 8 m{sup 2}/g to about 70 m{sup 2}/g.

  16. 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.

  17. 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.

  18. Structure-activity relationships of ruthenium Fischer-Tropsch catalysts (metal particle size effects)

    SciTech Connect

    White, M.W. Jr.

    1989-01-01

    In the group VIII transition metal catalytic conversion of hydrogen/carbon monoxide mixtures to hydrocarbons, it is known that certain catalysts catalyze the production of a narrow boiling range (C{sub 6}-C{sub 12}) product which does not fit the traditional Anderson-Schulz-Flory (ASF) chain growth model. Among the proposed explanations for this selectivity is one based on control of hydrocarbon chain propagation by metal particle size. The focus of this work was to study the effect of metal particle size on catalytic activity for the F-T synthesis. The silica-supported and unsupported Ru catalysts catalyzed the production of a hydrocarbon product which followed the ASF chain growth model and which consisted primarily of n-aklanes and linear 1-alkenes. An equation was derived relating the weight fraction of alkenes and alkanes to the residence times of the alkenes in the reactor and this equation produced a reasonable fit to the experimental data. It was observed that hydrocarbon, CO{sub 2} and CH{sub 4} production increased with time apparently reaching steady state after {approximately}200H. It was also found that increasing reactant gas space velocities (SHSV's) increased the steady state turnover numbers for hydrocarbon, CO{sub 2} and CH{sub 4} production, while at the same time, the AFS probabilities of chain growth and alkene/alkane ratios remained effectively constant.

  19. Fischer-Tropsch synthesis over iron-based catalysts in slurry reactors. Reaction rates, kinetics and implications for improving hydrocarbon productivity

    SciTech Connect

    Raje, A.P.; Davis, B.H.

    1996-10-01

    The Fischer-Tropsch (FT) synthesis is carried out over a high activity precipitated iron catalyst promoted with silica and potassium in a slurry reactor. Reaction rates (FTS and water gas shift) and partial pressures are evaluated over a wide range of CO conversions (10 to 90%) and space velocities at 270{degrees}C, 175 psig and a H{sub 2}/CO ratio of 0.67. The partial pressure of water exhibits a maximum at intermediate CO conversion. Both the fraction of CO converted to hydrocarbons and the hydrocarbon space time yield decrease with increasing CO conversion. This implies that it would be beneficial to have lower conversion per pass in the reactor with recycle to achieve a high overall conversion. The data as well as experiments with water and CO{sub 2} addition enable us to determine a kinetic expression for the catalyst which shows negligible inhibition of the reaction rate by water or CO{sub 2}.

  20. Promotional effects of Al{sub 2}O{sub 3} addition to Co/SiO{sub 2} catalysts for Fischer-Tropsch synthesis

    SciTech Connect

    Yi Zhang; Satoshi Nagamori; Sukamon Hinchiranan; Tharapong Vitidsant; Noritatsu Tsubaki

    2006-03-15

    The addition of a small amount of Al{sub 2}O{sub 3} to silica-supported cobalt catalysts significantly increased the dispersion of cobalt and Co-metallic surface area, resulting in the remarkable enhancement of the Fischer-Tropsch synthesis (FTS) activity in the slurry-phase reaction. The addition of Al{sub 2}O{sub 3} adjusted the interaction between cobalt and the silica support quite well, realizing the favored dispersion and reduction degree of supported cobalt and leading to high catalytic activity in FTS. The properties of various catalysts were characterized by in situ DRIFT, XRD, TPR, N{sub 2} physisorption, and H{sub 2} chemisorption. 16 refs., 3 figs., 2 tabs.

  1. 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

  2. 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.

  3. Synthesis of octane enhancers during slurry-phase Fischer Tropsch

    SciTech Connect

    Marcelin, G.

    1991-02-28

    The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch (FT) reaction. The three routes to be investigated are: addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch; addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst; and addition of methanol to slurry phase FT synthesis making iso-olefins. Work conducted during the first quarter has concentrated in the design of a laboratory-scale bubble column slurry reactor (BCSR) capable of operating at suitable temperatures and pressures for each of the three routes defined above. For design purposes the reactor has been configured as a one-inch diameter bubble column reactor for conversion of synthesis gas and operating with a wax paraffin (C{sub 30}{sup +}) liquid medium. This design has been finalized, thereby reaching milestone M1. The paper discusses the important design parameters (hydrodynamics, mass transfer, kinetics, and heat transfer) as well as the relationship of lab scale to industrial scale BCSR, parameter estimations, and the design of the bench-scale BCSR. 23 refs., 3 figs., 3 tabs.

  4. Microkinetic modelling of the formation of C 1 and C 2 products in the Fischer-Tropsch synthesis over cobalt catalysts

    NASA Astrophysics Data System (ADS)

    Storsæter, Sølvi; Chen, De; Holmen, Anders

    2006-05-01

    The heats of adsorption of different C 1 and C 2 molecules assumed to be present during the initial steps of the Fischer-Tropsch synthesis and activation energies for elementary steps envisioned to occur in the synthesis are calculated for Co by using the unity bond index-quadratic exponential potential (UBI-QEP) method. The preexponential factors for the elementary steps are calculated from transition-state theory, and the rate constants are calculated according to the Arrhenius equation. The activation barrier for hydrogenation of CO is found to be lower compared to hydrogen assisted dissociation of CO, which has a smaller activation barrier than direct dissociation of CO. The reaction steps with high activation barriers are eliminated. Based on this elimination two sets of elementary steps for formation of C 1 and C 2 alkenes and alkanes in the Fischer-Tropsch synthesis are established: one based on hydrogen assisted CO dissociation (carbide mechanism) and one based on CO hydrogenation (CO insertion mechanism). In addition, one mechanism of producing CO 2 from the water-gas shift reaction is proposed. The resulting mechanisms are combined and used in the microkinetic model, which are fitted to experimental results at methanation conditions ( T = 483 K or 493 K, p = 1.85 bar and H 2/CO = 10) over a Co/Al 2O 3 Fischer-Tropsch catalyst. A good tuning is obtained by adjusting the C-Co and H-Co binding strengths. The microkinetic modelling based on these assumptions indicates that CO is mainly converted through hydrogenation of CO and that C 2 compounds are mainly produced by insertion of CO into a metal-methyl bond. Thus, from the surface coverages and reaction rates predicted by the microkinetic modelling the mechanism can be further reduced to only include the CO insertion mechanism. Hydrogenation of CHO to CH 2O is found to be the rate determining initiation step, and insertion of CO into a metal-methyl bond is found to be the rate determining step for chain

  5. Development of a stable cobalt-ruthenium Fischer-Tropsch catalyst. Technical progress reports No. 7 and 8, April 1, 1991--September 30, 1991

    SciTech Connect

    Abrevaya, H.

    1991-12-31

    The objective of this contract is to examine the relationship between catalytic properties and the function of cobalt Fischer-Tropsch catalysts and to apply this fundamental knowledge to the development of a stable cobalt-based catalyst with a low methane-plus-ethane selectivity for use in slurry reactors. An experimental cobalt catalyst 585R2723 was tested three times in the fixed-bed reactor. The objective of the tests was to identify suitable testing conditions for screening catalyst. The {alpha}-alumina was determined to be a suitable diluent medium for controlling the catalyst bed temperature close to the inlet temperature. With 13 g of catalyst and 155 g of diluent, the catalyst maximum temperature were within 2{degree}C from the inlet temperatures. As a result of this work, 210{degree}C and 21 atm were shown to result in low methane selectivity and were used as initial conditions in the catalyst screening test. Ethane, which along with methane is undesirable, is typically produced with low selectivity and follows the same trend as methane. Other work reported here indicated that methane selectivity increases with increasing temperature but is not excessively high at 230{degree}C. Consequently, the catalyst screening test should include an evaluation of the catalyst performance at 230{degree}C. During Run 67, the increase in temperature from 210{degree}C to 230{degree}C was initiated at 30 hours on-stream.

  6. Fischer-Tropsch synthesis in supercritical reaction media

    SciTech Connect

    Subramaniam, B.; Bochniak, D.; Snavely, K.

    1993-01-01

    Our goals for this quarter were to complete construction of the reactor and analytical units for carrying out Fischer-Tropsch (F-T) synthesis in liquid (n-hexadecane) and in supercritical n-hexane phases. Progress during this quarter was slower than expected.

  7. Investigation on the Fischer-Tropsch synthesis with nitrogen-containing syngas over CoPtZrO{sub 2}/Al{sub 2}O{sub 3} catalyst

    SciTech Connect

    Dongyan Xu; Hongmin Duan; Wenzhao Li; Hengyong Xu

    2006-05-15

    The Fischer-Tropsch synthesis with nitrogen-containing syngas derived from combined air partial oxidation and CO{sub 2} reforming of methane has been performed in a fixed-bed reactor. The effects of key factors including reaction temperature, pressure, and nitrogen content of the syngas on the performance of CoPtZrO{sub 2}/Al{sub 2}O{sub 3} catalyst were mainly investigated. The results indicate that the syngas containing a high content of nitrogen is suitable for Fischer-Tropsch synthesis and that a high initial catalytic activity can be achieved under typical operating conditions. The decreasing of catalytic activity with time on stream before reaching steady state was observed, which is mainly due to the blockage of catalyst pores by heavy hydrocarbons. 22 refs., 7 figs.

  8. 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

  9. Conversion of cellulosic wastes to liquid hydrocarbon fuels: Vol. 2, A kinetic study of the modified Fischer-Tropsch synthesis over an alumina-supported cobalt oxide catalyst: Final report

    SciTech Connect

    Kuester, J.L.

    1986-11-01

    A modified Fischer-Tropsch reaction with the incorporation of ethylene in the synthesis gas has been studied kinetically. The feed mixture was also comprised of methane and carbon dioxide in a proportion similar to a real pyrolysis gas composition. The feed gas was provided by a manifold of compressed gas cylinders. An alumina-supported cobalt oxide catalyst was prepared by an impregnation method and used in the experimentation.

  10. The selective catalytic cracking of Fischer-Tropsch liquids to high value transportation fuels. Report number 13: Quarterly technical progress report for second quarter fiscal year 1992 (January 1--March 31, 1992)

    SciTech Connect

    Reagan, W.J.

    1992-12-31

    Amoco Oil Company is investigating a selective catalytic cracking process to convert the Fischer-Tropsch gasoline and wax fractions to high value transportation fuels. The wax feedstock for this program is a commercial sample of Fischer-Tropsch product from Sasol. The wax feedstock readily converts over conventional fluid catalytic cracking (FCC) catalysts (85%+ conversion) to high yields of C{sub 4}-gas and gasoline. The work in this area focuses on the effects of process variables and catalyst types. Some initial wax cracking tests on the pilot plant unit continue. These test results also show high conversion (85%+) of the wax feedstock to light gases and gasoline. The ranking of the three zeolite catalyst types for C{sub 4}-C{sub 5} iso-olefin production is similar to the findings of the small scale screening test program. The catalytic cracking test results from both the small scale test unit and the pilot plant suggest that very mild process conditions and low activity catalysts are needed to lower the overall wax conversion. The target light olefin yields vary with catalyst type and the process conditions.

  11. Fischer-Tropsch synthesis of hydrocarbons

    SciTech Connect

    Lampert, A.; Erickson, J.; Smiley, B.; Vaughan, C.

    1983-09-01

    The performance of an iron-copper Fischer-Tropsch catalyst was studied in a slurry CSTR at 227/sup 0/C and 790 kPa (100 psig). Catalyst performance was similar to other iron-based catalysts studied previously with respect to conversion of CO, conversion of CO + H/sub 2/, and to the product distribution. CO conversion increased with decreasing space velocity, ranging from approximately 60% at 1570 h/sup -1/ to over 90% at 488 h/sup -1/. The H/sub 2/ to CO usage ratio was approximately 0.7, indicating that the catalyst is a good water-gas shift catalyst as well as a Fischer-Tropsch catalyst. Reaction products could be described by a Flory distribution with a chain growth probability (..cap alpha..) of 0.67, which is in the gasoline range. In some runs, methanol was added continuously to the reactor feed, but instead of being incorporated into the reaction, the methanol oxidized and deactivated the catalyst. 31 references, 12 figures, 10 tables.

  12. 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.

  13. 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.

  14. Effects of H/sub 2/O and CO/sub 2/ on the activity and composition of iron Fischer-Tropsch catalysts

    SciTech Connect

    McDonald, M.A.

    1986-01-01

    The composition of an iron Fischer-Tropsch (F-T) catalyst is strongly affected by the % conversion of H/sub 2/-CO syngas. At low % conversion, the strongly reducing syngas mixture tends to covert metallic or oxidic iron species to a bulk iron carbide phase or phases. As % syngas conversion increases, H/sub 2/ and CO are converted to organic products, and to H/sub 2/O and CO/sub 2/. The gas mixture can therefore oxidize an iron catalyst. However, the catalyst's synthesis behavior (activity, selectivity, activity and selectivity maintenance) also depends strongly on % syngas conversion. Thus, an iron catalyst's composition and synthesis behavior are not easily correlated under typical F-T reaction conditions. This study was designed to determine how the build-up of H/sub 2/O and CO/sub 2/ during reaction affect F-T catalyst composition and synthesis behavior. Reaction rate measurements were conducted at differential % syngas conversion using catalyst wafers mounted in an in-situ cell. This cell allowed Mossbauer effect spectroscopy of the used catalyst for determination of the catalyst composition. Additional H/sub 2/O and CO/sub 2/ were added to syngas to determine the effects on catalyst composition, activity and selectivity. Furthermore, these experiments were carried out at pressures well above atmospheric, the pressure range required for good iron F-T catalyst behavior. Thus, results presented here are more closely related to the state of working F-T catalysts than are previous in-situ Mossbauer studies of iron catalysts, which were done almost exclusively at atmospheric pressure. This paper focuses on initial experiments involving the addition of only H/sub 2/O, not CO/sub 2/, to a syngas stream.

  15. Influence of gas feed composition and pressure on the catalytic conversion of CO{sub 2} to hydrocarbons using a traditional cobalt-based Fischer-Tropsch catalyst

    SciTech Connect

    Robert W. Dorner; Dennis R. Hardy; Frederick W. Williams; Burtron H. Davis; Heather D. Willauer

    2009-08-15

    The hydrogenation of CO{sub 2} using a traditional Fischer-Tropsch Co-Pt/Al{sub 2}O{sub 3} catalyst for the production of valuable hydrocarbon materials is investigated. The ability to direct product distribution was measured as a function of different feed gas ratios of H{sub 2} and CO{sub 2} (3:1, 2:1, and 1:1) as well as operating pressures (ranging from 450 to 150 psig). As the feed gas ratio was changed from 3:1 to 2:1 and 1:1, the production distribution shifted from methane toward higher chain hydrocarbons. This change in feed gas ratio is believed to lower the methanation ability of Co in favor of chain growth, with possibly two different active sites for methane and C2-C4 products. Furthermore, with decreasing pressure, the methane conversion drops slightly in favor of C{sub 2}-C{sub 4} paraffins. Even though under certain reaction conditions product distribution can be shifted slightly away from the formation of methane, the catalyst studied behaves like a methanation catalyst in the hydrogenation of CO{sub 2}. 36 refs., 2 figs., 4 tabs.

  16. 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.

  17. 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.

  18. 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}.

  19. Development of a stable cobalt-ruthenium Fischer-Tropsch catalyst. Technical progress report No. 12, July 1, 1992--September 30, 1992

    SciTech Connect

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

    1992-12-31

    The fixed bed pilot plant, the catalyst testing procedure, and the calculations for conversion and selectivities were previously described in the technical progress report covering the period of 3/16/88 to 6/16/88 for Contract DE-AC22-87PC79812. Conversions and hydrocarbon selectivities were calculated using data from an on-line gas chromatography (GC) analyzer. Alcohol selectivities were calculated using data from an on-line boiling point GC analyzer which analyzed the liquid product. The catalysts were prepared via the steps of impregnation, calcination, and reduction on a special Y-zeolite-derived support. The impregnation step consisted of evaporation of metal salts on to the support from an aqueous solution. For one catalyst (No. 6531-188) the metal salts were evaporated on to the support from a reverse micelle solution containing the metal salts. All the catalysts were calcined for four hours at 450{degree}C. The calcined catalysts were loaded in the reactor with a diluent (usually quartz sand) and reduced in-situ for four hours in flowing hydrogen at 350{degree}C. The diluent helps in the removal of heat from the very exothermic Fischer-Tropsch reaction. The catalyst preparation method is summarized in detail in Figure 1. For catalyst testing runs discussed in this report and not summarized previously in earlier reports, run summary plots of conversions and selectivities vs hours-on-stream are attached in Appendix A. Catalyst compositions are shown in Table 2 and summary performance data are shown in Tables 3 and 4.

  20. 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

  1. The selective catalytic cracking of Fischer-Tropsch liquids to high value transportation fuels. Report number 24: Quarterly technical progress report for fourth quarter fiscal year 1992 (July 1--September 30, 1992)

    SciTech Connect

    Reagan, W.J.

    1992-12-31

    Amoco Oil Company is investigating a selective catalytic cracking process to convert the Fischer-Tropsch gasoline and wax fractions to high value transportation fuels. The wax feedstock for this program, a commercial sample of fischer-Tropsch product from Sasol, is a high melting point, (>220 F), high boiling range (50% boiling above 1,000 F), largely paraffinic material. The wax feedstock readily converts over conventional fluid catalytic cracking (FCC) catalysts (85%+ conversion) to high yields of C{sub 4}-gas and naphtha. Three different types of zeolite catalysts and one amorphous cracking catalyst show wide variations of product yields as a function of wax feedstock conversion. The Beta and HZSM-5 zeolite catalysts have higher target light olefin (isobutylene and isoamylenes) yields than the Y zeolite sample. The HSZM-5 sample also produces the highest yields of propylene. Further work continues on various commercial and experimental HZSM-5 samples. There are some clear wax conversion variations among the samples. However, product selectivity differences are small and difficult to measure accurately. A series of rare earth exchanged Y zeolite catalysts show the expected rare earth effect: increased rare earth exchange gives higher naphtha and lower olefin yields. Several new FCC catalysts with low (10%) zeolite content have been prepared and analyzed. The zeolite Beta sample appears to have a lower hydrothermal stability than zeolite Y catalyst. The catalytic cracking test results from both the small scale test unit and the pilot plant suggest that very mild process conditions and low activity catalysts are needed to lower the overall wax conversion. The target light olefin yields vary with catalyst type and the process conditions.

  2. 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.

  3. 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.

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

    NASA Astrophysics Data System (ADS)

    Sartipi, Sina; Jansma, Harrie; Bosma, Duco; Boshuizen, Bart; Makkee, Michiel; Gascon, Jorge; Kapteijn, Freek

    2013-12-01

    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.

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

    PubMed

    Sartipi, Sina; Jansma, Harrie; Bosma, Duco; Boshuizen, Bart; Makkee, Michiel; Gascon, Jorge; Kapteijn, Freek

    2013-12-01

    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. PMID:24387446

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. Fischer-Tropsch synthesis in slurry-reactor systems. Quarterly report, August 1, 1982-October 31, 1982

    SciTech Connect

    Satterfield, C.N.; Bartos, T.; Stenger, H.

    1982-01-01

    An Mn/Fe catalyst prepared at the Technical University of Berlin was studied under a set of conditions chosen to compare the results with a reduced fused magnetite catalyst and with a similar catalyst studied by Deckwer et al. (I.E.C. Proc. Des. Dev., 21, 222 (1982)). The results are presented in the form of a manuscript attached herewith that has been submitted to the same journal for publication. The pattern of product selectivity with the Mn/Fe catalyst was very similar to that observed with a reduced fused magnetite catalyst in the same apparatus, but the olefin/paraffin ratio at all carbon numbers was less than that with the reduced magnetite catalyst. With both catalysts the Flory-Schultz distribution was followed but two values of the chain growth probability, ..cap alpha.., were found, with a sharp discontinuity at about C/sub 11/. ..cap alpha.. values based on the C/sub 1/-C/sub 10/ products were less for the Mn/Fe catalyst than for the fused Fe catalyst, attributed to the absence of potassium in the Mn/Fe catalysts.

  11. Fischer-Tropsch synthesis with coal derived syngas

    SciTech Connect

    Raje, A.; O`Brien, R.J.; Davis, B.H.

    1998-12-31

    The effect of potassium on catalyst activity, kinetic parameters and selectivity has been investigated for a precipitated iron catalyst with low H{sub 2}/CO ratio synthesis gas. A wide range of synthesis gas conversions have been obtained by varying space velocities over catalysts with various potassium loadings. Differing trends in catalyst activity with potassium loading were observed depending on the space velocity or synthesis gas conversion. As potassium loading increased, the catalyst activity either decreased (low conversions), passed through a maximum (intermediate conversions) or increased (high conversions). This is shown to be a result of the increasing dependency of the Fischer-Tropsch synthesis on the hydrogen formed by the water-gas shift reaction with increasing synthesis gas conversions. Both the rate constant and the adsorption parameter in a common two-parameter Fischer-Tropsch rate expression decreased with potassium loading; therefore, observed maxima in Fischer-Tropsch rate with potassium loading can be due to the opposing influences of these parameters.

  12. Zirconia promotion of Fischer-Tropsch cobalt catalysts: Behavior in fixed-bed and slurry bubble column reactors

    SciTech Connect

    Oukaci, R.; Goodwin, J.G. Jr.; Marcelin, G.; Singleton, A.

    1995-12-31

    A series of cobalt-based F-T catalysts supported on alumina and silica were prepared with different loadings of Zr and different sequence of impregnation of Co and Zr. All catalysts were extensively characterized by different methods. The catalysts were evaluated in terms of their activity and selectivity both in fixed bed and slurry bubble column reactors. Addition of ZrO{sub 2} to both CO/SO{sub 2} and Co/Al{sub 2}O{sub 3} catalysts resulted in at least a twofold increase in the catalyst activity for F-T synthesis in the fixed bed reactor. In the slurry bubble column reactor, a similar promotion effect was observed for the SO{sub 2}-supported catalysts, while the addition of Zr to a cobalt/alumina catalyst had a less significant effect.

  13. 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

  14. Zirconia promotion of Fischer-Tropsch cobalt catalysts: Behavior in fixed bed and slurry bubble column reactors

    SciTech Connect

    Oukaci, R.; Goodwin, J.G. Jr.; Marcelin, G.; Singleton, A.

    1995-12-01

    A series of cobalt-based F-T catalysts supported on alumina and silica were prepared with different loadings of Zr and with different sequences of impregnation of Co and Zr. All catalysts were extensively characterized by different methods. The catalysts were evaluated in terms of their activity and selectivity both in fixed bed and slurry bubble column reactors. Addition of ZrO{sub 2} to both Co/SiO{sub 2} and Co/Al{sub 2}O{sub 3} catalysts resulted in at least a two-to-threefold increase in the catalyst activity for F-T synthesis in the fixed bed reactor, depending on the sequence of impregnation of Co and Zr. In the slurry bubble column reactor the promotion effect was observed only for the SiO{sub 2}-supported catalyst.

  15. 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

  16. 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

  17. Application of equilibrium analysis to a Fischer-Tropsch product

    SciTech Connect

    Norval, G.W. ); Phillips, M.J. )

    1990-11-01

    In the Fischer-Tropsch (FT) process, synthesis gas is converted, inter alia, to aliphatic hydrocarbons, consisting predominantly of n-alkanes and n-alkenes, over iron- or cobalt-based catalysts. The product composition follows an Anderson-Schults-Flory (ASF) distribution. In this paper, the authors demonstrate that the ASF distribution (Eq. (1)) can be derived from an equilibrium basis, and the consequences arising therefrom are discussed.

  18. Effect of surface modification by chelating agents on Fischer-Tropsch performance of Co/SiO2 catalysts

    SciTech Connect

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

    2013-01-01

    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 shows 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. 1. INTRODUCTION Fischer−Tropsch (FT) synthesis has been recognized as one of the most promising technologies for the conversion of coal, natural gas, and biomass-derived syngas into liquid fuels and chemicals.1 Limited oil reserves, energy supply security concerns, carbon credits,1 pollution abatement laws, and, most notably, uncertainty about fuel prices have increased the prospect of commercializing the FT process. Catalysts that are typically used for FT synthesis include supported Co or Fe. Cobased catalysts have the advantage of higher syngas conversion, more high-

  19. 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

  20. 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. PMID:25938725

  1. Combinatorial computational chemistry approach as a promising method for design of Fischer Tropsch catalysts based on Fe and Co

    NASA Astrophysics Data System (ADS)

    Belosludov, Rodion V.; Sakahara, Satoshi; Yajima, Kenji; Takami, Seiichi; Kubo, Momoji; Miyamoto, Akira

    2002-04-01

    The combinatorial computational chemistry approach was applied to design new types of catalysts, which can be used in the Fisher-Tropsh (FT) synthesis for the production of ecologically high-quality transportation fuels. For this purpose, the density functional theory (DFT) was used to investigate the CO adsorption on Fe- and Co-based multi-component catalysts. The energetic, electronic and structural properties of CO on the catalyst surfaces were calculated. It was found that Mn, Mo, and Zr could be used as additional elements in the Fe- and Co-based catalysts, since one cannot observe a degradation of the adsorption properties of the active sites as well as showing a high sulfur tolerance. For the Co-based catalyst, the same tendency is also found in the case of the Si promoter. The obtained results are in agreement with available experimental data that confirmed the validity of combinatorial computational chemistry approach.

  2. Fischer-Tropsch synthesis in supercritical reaction media. [Quarterly] progress report, July 1, 1993--September 30, 1993

    SciTech Connect

    Subramaniam, B.

    1993-10-01

    Figure 1 shows the physical appearance of the reactor and analytical units. The feed preparation section consists of a mass flow controller for syngas introduction, the BPLC pump for n-hexane introduction, preheaters, check valves, static mixer, and safety head has been completed. The stainless steel reactor was fabricated and was alonized to passivate the stainless steel surface. The fluidized sand bath surrounding the reactor was fabricated in house. Aluminum oxide (120 mesh) will be used as the fluidized medium. Stepping-motor-driven micrometering (Autoclave{reg_sign}) valves have been installed for pressure control of the reactor and of the syngas feed stream. The sample transfer lines connected to the gas sampling valves in the GC will be routed inside the valve oven and out through the front top of the GC, where they will be connected with the heated sample transfer lines from the reactor. The sample outlet line will be routed through a cold trap operated at 20{degrees}C or lower and the gases from the cold trap will be exhausted to the roof vent. The reactor unit is versatile and permits us to investigate the effect(s) of any of the following variables on syngas conversion, selectivity and reaction rate maintenance: (1) pressure (25--70) bars, (2) syngas flowrate (30--150) cc/min/g{center_dot}cat, (3) syngas ratio (H{sub 2}/CO of 0.5, 1.0 or 2.0) (4) ratio of syngas to reaction media (0.2--5.0), (5) catalyst type (Fe or Co), (6) direction of cocurrent flow (upflow or downflow), (7) cosolvent effects (such as n-pentane), and (8) sulfur content (1--50 mg{center_dot}/g{center_dot}Fe). Based on a literature review (Pennline et al., 1987; Baltrus et al., 1989; Bukur et al., 1990), the pretreatment of Fe catalysts will be performed with flowing CO at low pressure ({approximately}1 atm) and high temperatures ({approximately}280{degrees}C).

  3. Influence of the support on the activity and selectivity of high dispersion Fe catalysts in the Fischer-Tropsch reaction

    SciTech Connect

    Cagnoli, M.V.; Marchetti, S.G.; Gallegos, N.G.; Alvarez, A.M.; Mercader, R.C.; Yeramian, A.A. Facultad de Ciencias Exactas, La Plata )

    1990-05-01

    In order to study the influence of the support on high dispersion catalysts used for the CO hydrogenation reaction, two catalysts, Fe/SiO{sub 2} and Fe/Al{sub 2}O{sub 3}, were prepared by the dry impregnation method. Selective chemisorption of CO, volumetric oxidation, and Moessbauer spectroscopy were used to determine the Fe species present as well as the metallic crystal size, the degree of dispersion, and the reduction percentage. The presence of small Fe{sup 0} crystallites with high dispersion was determined in both catalysts. Reaction rates were measured in a differential reactor and significant differences, about one order of magnitude less for the Al{sub 2}O{sub 3} than for the SiO{sub 2} supported catalysts, were found in the methane turnover frequencies. They are attributed to the interaction between the metal and the supports. The selectivity differences is also discussed in connection with distinct surface properties.

  4. Slurry-phase Fischer-Tropsch synthesis

    SciTech Connect

    Zarochak, M.F.; McDonald, M.A.

    1986-01-01

    Fischer-Tropsch synthesis in the slurry phase has attracted attention in recent years due to its numerous advantages. Among these advantages are the ability of the liquid phase to handle the large heats of reaction and thereby control reaction temperature, the ability to handle low H/sub 2//CO ratio synthesis gas without needing a preliminary water-gas shift step, and the relatively low capital and operating costs for slurry systems. Slurry-phase work at PETC has focused on understanding effects of catalyst preparation and pretreatment, of reaction conditions (T, P, H/sub 2//CO), and of operating conditions (space velocity, methods of wax removal) on catalyst synthesis behavior (activity, selectivity, and maintenance of activity and selectivity). Better understanding of the effects of these factors on F-T synthesis leads to improvements in process technology. This work focuses on the effects of catalyst pretreatment on synthesis behavior. Developing an effective F-T catalyst pretreatment procedure is a problem limited almost exclusively to iron catalysts. This paper reports some recent results on the effects of pretreatment. Synthesis runs were made using one of two different pretreatments given a potassium-promoted precipitated iron catalyst. Besides these reaction experiments, catalyst samples were periodically withdrawn from the stirred autoclave for characterization by means of Moessbauer spectroscopy.

  5. 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.

  6. 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.

  7. 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

    2015-11-01

    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. PMID:26547178

  8. The selective catalytic cracking of Fischer-Tropsch liquids to high value transportation fuels. Report number 38: Quarterly technical status report for fourth quarter fiscal year 1993 (July 1--September 30, 1993)

    SciTech Connect

    Schwartz, M.M.

    1993-12-31

    Amoco Oil Company is investigating a selective catalytic cracking process to convert the Fischer-Tropsch gasoline and wax fractions to high value transportation fuels. This report contains the most current and accurate information and projections of the scope of work, schedules, milestones, staffing/manpower plan and costs. Naphtha that was produced by the Liquid Phase F-T demonstration plant at LaPorte, Texas was received and characterized. Three pilot plant runs were completed using Sasol wax as feedstock. The catalysts used were 10% steamed USY, 10% steamed Beta, and standard equilibrium USY. The 10% Beta catalyst gave much higher yields of propylene and butylenes than the USY-based catalysts, in agreement with previous results. Characterization of the IBP-430, 430--650 and 650+ F fractions of these runs is incomplete. The 10% Beta catalyst made 430--650 F product with the highest cetane index (60.9), but the 430--650 F product from all three runs would be excellent stock for blending into diesel fuel.

  9. Synthesis of octane enhancers during slurry-phase Fischer-Tropsch

    SciTech Connect

    Marcelin, G.

    1992-09-24

    The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: addition of i-butylene during the formation of methanol and/or higher alcohols directly from CO and H[sub 2] during slurry-phase Fischer-Tropsch; addition of i-butylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst; and addition of methanol to slurry phase FT synthesis making iso-olefins. During the seventh quarter we continued the shake down experiments for the SBCR and conducted an initial aborted run. We have also re-started experiments on Scheme 1, i.e., the addition of iso-butylene during CO hydrogenation. Using a dual bed arrangement, we have demonstrated the synthesis of MTBE from syngas and iso-butylene.

  10. 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.

  11. Cobalt catalysts, and use thereof for the conversion of methanol and for fischer-tropsch synthesis, to produce hydrocarbons

    SciTech Connect

    Mauldin, C.H.; Davis, S.M.; Arcuri, K.B.

    1988-08-09

    This patent describes a process useful for the conversion of methanol to hydrocarbons which comprises contacting the methanol at reaction conditions with a catalyst which comprises from about 2 percent to about 25 percent cobalt, based on the weight of the catalyst composition, composited with titania, or a titania-containing support, to which is added a zirconium, hafnium, cerium, or uranium promoter, the weight ratio of the zirconium, hafnium, cerium, or uranium metal:cobalt being greater than about 0.010:1; the reaction conditions being defined within ranges as follows: Methanol:H/sub 2/ ratio: greater than about 4:1, Space Velocities, Hr/sup -1/:about 0.1 to 10, Temperatures, /sup 0/C.:about 150 to 350, Methanol Partial Pressure, psia: about 100 to 1000.

  12. 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

  13. Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst, January 1, 1990--March 30, 1990

    SciTech Connect

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

    1990-01-01

    Experiments to study cobalt-catalyzed reactions of light 1-alkenes added to synthesis gas feed have been performed. Data have been collected at 220{degrees}C, 0.45 to 1.48 MPa and a synthesis gas flow rate between 0.015 and 0.030 Nl/(gcatmin) with H{sub 2}/CO of 1.45 to 2.25. C{sub 2}H{sub 4}, C{sub 3}H{sub 6}, and C{sub 4}H{sub 8} were added to the synthesis gas feed in concentrations ranging from 0.5 to 1.2 mole% of total feed. For each material balance in which 1-alkenes were added, a material balance was performed at similar process conditions without 1-alkenes added. This use of base case'' process conditions should make data analysis and interpretation easier. Material balances without 1-alkenes were also repeated to allow verification of catalyst selectivity stability. A total of 49 balances were performed during a single run which lasted over 2500 hours-on-stream. The hydrocarbon data have not yet been completed analyzed.

  14. Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst, January 1, 1990--March 30, 1990

    SciTech Connect

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

    1990-12-31

    Experiments to study cobalt-catalyzed reactions of light 1-alkenes added to synthesis gas feed have been performed. Data have been collected at 220{degrees}C, 0.45 to 1.48 MPa and a synthesis gas flow rate between 0.015 and 0.030 Nl/(gcatmin) with H{sub 2}/CO of 1.45 to 2.25. C{sub 2}H{sub 4}, C{sub 3}H{sub 6}, and C{sub 4}H{sub 8} were added to the synthesis gas feed in concentrations ranging from 0.5 to 1.2 mole% of total feed. For each material balance in which 1-alkenes were added, a material balance was performed at similar process conditions without 1-alkenes added. This use of ``base case`` process conditions should make data analysis and interpretation easier. Material balances without 1-alkenes were also repeated to allow verification of catalyst selectivity stability. A total of 49 balances were performed during a single run which lasted over 2500 hours-on-stream. The hydrocarbon data have not yet been completed analyzed.

  15. 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.

  16. The selective catalytic cracking of Fischer-Tropsch liquids to high value transportation fuels. Report number 30: Quarterly technical status report for second quarter fiscal year 1993 (January 1--March 31, 1993)

    SciTech Connect

    Schwartz, M.M.

    1993-12-31

    Amoco Oil Company is investigating a selective catalytic cracking process to convert the Fischer-Tropsch gasoline and wax fractions to high value transportation fuels. Experiments with the LaPorte wax as feedstock demonstrated the feasibility of the concept of selective attrition of the FCC catalyst. Experiments comparing the Sasol and LaPorte wax feedstocks with USY, Beta and HZSM-5 catalysts showed that the type of FCC catalyst has a major impact upon product yields and quality. For a given catalyst, both feedstocks have similar conversion values. The yields of the major catalytic cracking products, light olefins, naphtha and distillate, do not vary significantly with the two wax feedstocks. The methanol etherification of the light naphtha product from the pilot plant F-T wax cracking runs yields a mixed ether product. Etherification runs were completed on two additional pilot plant light naphthas using two commercial etherification catalysts, one of which contains a noble metal, in addition to the strong acid functionality. Isoolefin conversion values were similar for the two catalysts and three feedstocks in the absence of H{sub 2}. With H{sub 2} present, product color is improved; but overall the presence of H{sub 2} is not desirable because olefins are saturated, which results in decreased production of ethers and decreased product octane number. Economic analysis of the eight pilot plant runs that were performed under Task 4 showed that the net production values for a complex refinery were always higher than for a simple refinery (no ether unit).

  17. Fischer-Tropsch synthesis in supercritical reaction media. Progress report, October 1, 1992--December 31, 1992

    SciTech Connect

    Subramaniam, B.; Bochniak, D.; Snavely, K.

    1993-01-01

    Our goals for this quarter were to complete construction of the reactor and analytical units for carrying out Fischer-Tropsch (F-T) synthesis in liquid (n-hexadecane) and in supercritical n-hexane phases. Progress during this quarter was slower than expected.

  18. Process design and solvent recycle for the supercritical Fischer-Tropsch synthesis

    SciTech Connect

    Wensheng Linghu; Xiaohong Li; Kenji Asami; Kaoru Fujimoto

    2006-02-01

    A recycle reactor system for supercritical Fischer-Tropsch synthesis was successfully designed and tested. The new reactor system has these characteristics: (1) integration of supercritical Fischer-Tropsch reactions, natural separation of produced wax from liquid phase, and recycle of the solvent and (2) natural recycle of solvent driven by self-gravity. A 20% Co/SiO{sub 2} catalyst and n-hexane were used as a catalyst and supercritical fluid, respectively. The results show that the average CO conversion at the steady state was 45% with recycle and 58% without recycle. The lumped hydrocarbon products distribution did not have any obvious difference between with and without recycle operation; however, {alpha}-olefin content of products with recycle was lower than that without recycle. The XRD result indicates that most of the reduced cobalt remains in the metallic state during the Fischer-Tropsch reactions for both cases. 22 refs., 3 figs., 1 tab.

  19. Ordered mesoporous carbon nanochannel reactors for high-performance Fischer-Tropsch synthesis.

    PubMed

    Ha, Kyoung-Su; Kwak, Geunjae; Jun, Ki-Won; Hwang, Jongkook; Lee, Jinwoo

    2013-06-01

    A hexagonally ordered mesoporous carbon, CMK-3, was utilized as a support for a Fischer-Tropsch catalyst. Each array of elongated pore structures with Co nanoparticles can be regarded as a nanochannel reactor. Due to the pore confinement and the hydrophobic nature of the support, this catalyst demonstrated excellent catalytic performance. PMID:23482917

  20. The facile fabrication of magnetite nanoparticles and their enhanced catalytic performance in Fischer-Tropsch synthesis.

    PubMed

    Zheng, Shenke; Sun, Jiaqiang; Song, Dechen; Chen, Zheng; Chen, Jiangang

    2015-07-14

    Uniform and crystalline magnetite nanoparticles are facilely fabricated and utilized as an efficient catalyst in Fischer-Tropsch synthesis (FTS). The catalyst exhibits a high and stable activity with low methane selectivity, attributed to its remarkable structural and chemical stability at the realistic conditions of FTS. PMID:26074335

  1. Synthesis of octane enhancer during slurry-phase Fischer-Tropsch

    SciTech Connect

    Marcelin, G.

    1991-12-15

    The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch. Addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst. Addition of methanol to slurry phase FT synthesis making iso-olefins.

  2. Synthesis of octane enhancers during slurry-phase Fischer-Tropsch

    SciTech Connect

    Marcelin, G.

    1992-06-10

    The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch. Addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst. Addition of methanol to slurry phase FT synthesis making iso-olefins.

  3. Synthesis of octane enhancers during slurry-phase Fischer-Tropsch

    SciTech Connect

    Marcelin, G.

    1991-10-15

    The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butytl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: (1) Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch; (2) addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst; and, (3) addition of methanol to slurry phase FT synthesis making iso-olefins.

  4. Multicomponent modelling of Fischer-Tropsch slurry reactors

    SciTech Connect

    Van Vuuren, D.S.; Heydenrych, M.D.

    1985-08-01

    In the multicomponent model developed for a Fischer-Tropsch slurry reactor, the water-gas shift reaction is assumed to be in equilibrium. This is supported by literature data on iron-based catalysts above 523 K and synthesis gas conversion above about 50%. A Schulz-Flory product distribution is used. Investigation of the effects of back-mixing and interphase mass transfer using the model shows that, although the mass transfer rates in full-scale reactors are fast compared with reaction rates, the ratio of the mass transfer rates of reactants and products is important in determining gas velocity and gas hold-up and hence reactor performance.

  5. Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. [801Methyl tert-butyl ether

    SciTech Connect

    Marcelin, G.

    1992-06-24

    The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: (1) Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch. (2) Addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst. (3) Addition of methanol to slurry phase FT synthesis making iso-olefins. During the sixth quarter we completed the construction of the slurry bubble column reactor (SBCR), conducted initial shake-down experiments in a cold-flow mode, and finalized the selection process of the acid catalysts for conversion of syngas-produced alcohols and isobutylene to MTBE (scheme 2). Tasks 3, 4, and 5 are awaiting complete implementation of the SBCR system.

  6. Microkinetics of oxygenate formation in the Fischer-Tropsch reaction.

    PubMed

    van Santen, Rutger A; Ghouri, Minhaj; Hensen, Emiel M J

    2014-06-01

    Microkinetics simulations are presented on the intrinsic activity and selectivity of the Fischer-Tropsch reaction with respect to the formation of long chain oxygenated hydrocarbons. Two different chain growth mechanisms are compared: the carbide chain growth mechanism and the CO insertion chain growth mechanism. The microkinetics simulations are based on quantum-chemical data on reaction rate parameters of the elementary reaction steps of the Fischer-Tropsch reaction available in the literature. Because the overall rate constant of chain growth remains too low the CO insertion chain growth mechanism is not found to produce higher hydrocarbons, except for ethylene and acetaldehyde or the corresponding hydrogenated products. According to the carbide mechanism available quantum-chemical data are consistent with high selectivity to long chain oxygenated hydrocarbon production at low temperature. The anomalous initial increase with temperature of the chain growth parameter observed under such conditions is reproduced. It arises from the competition between the apparent rate of C-O bond activation to produce "CHx" monomers to be inserted into the growing hydrocarbon chain and the rate of chain growth termination. The microkinetics simulations data enable analysis of selectivity changes as a function of critical elementary reaction rates such as the rate of activation of the C-O bond of CO, the insertion rate of CO into the growing hydrocarbon chain or the rate constant of methane formation. Simulations show that changes in catalyst site reactivity affect elementary reaction steps differently. This has opposing consequences for oxygenate production selectivity, so an optimizing compromise has to be found. The simulation results are found to be consistent with most experimental data available today. It is concluded that Fischer-Tropsch type catalysis has limited scope to produce long chain oxygenates with high yield, but there is an opportunity to improve the yield of C2

  7. 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.

  8. 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.

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

    PubMed

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

    2015-10-01

    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. PMID:26449809

  10. Mechanism and microkinetics of the Fischer-Tropsch reaction.

    PubMed

    van Santen, R A; Markvoort, A J; Filot, I A W; Ghouri, M M; Hensen, E J M

    2013-10-28

    The increasing availability of quantum-chemical data on surface reaction intermediates invites one to revisit unresolved mechanistic issues in heterogeneous catalysis. One such issue of particular current interest is the molecular basis of the Fischer-Tropsch reaction. Here we review current molecular understanding of this reaction that converts synthesis gas into longer hydrocarbons where we especially elucidate recent progress due to the contributions of computational catalysis. This perspective highlights the theoretical approach to heterogeneous catalysis that aims for kinetic prediction from quantum-chemical first principle data. Discussion of the Fischer-Tropsch reaction from this point of view is interesting because of the several mechanistic options available for this reaction. There are many proposals on the nature of the monomeric single C atom containing intermediate that is inserted into the growing hydrocarbon chain as well as on the nature of the growing hydrocarbon chain itself. Two dominant conflicting mechanistic proposals of the Fischer-Tropsch reaction that will be especially compared are the carbide mechanism and the CO insertion mechanism, which involve cleavage of the C-O bond of CO before incorporation of a CHx species into the growing hydrocarbon chain (the carbide mechanism) or after incorporation into the growing hydrocarbon chain (the CO insertion mechanism). The choice of a particular mechanism has important kinetic consequences. Since it is based on molecular information it also affects the structure sensitivity of this particular reaction and hence influences the choice of catalyst composition. We will show how quantum-chemical information on the relative stability of relevant reaction intermediates and estimates of the rate constants of corresponding elementary surface reactions provides a firm foundation to the kinetic analysis of such reactions and allows one to discriminate between the different mechanistic options. The paper will

  11. Fischer-Tropsch synthesis for clean transportation fuels

    SciTech Connect

    Xu, L.; Bao, S.; O`Brien, R.J.; Raje, A.; Davis, B.H.

    1997-12-31

    The products from the Fischer-Tropsch synthesis and the rates of conversion of the reactants (H{sub 2} and CO) have been determined for a range of flow rates. Based upon conversion rates, an iron catalyst should be utilized at lower CO conversion levels. The fraction of CO converted to hydrocarbons decreases with increasing CO conversion. Thus, it is suggested that a F-T process employing recycle or multiple reactors is more appropriate for an iron catalyst than operating a single reactor at high (> 95%) CO conversion levels. The data indicate that an iron catalyst is preferred over a cobalt catalyst for some process conditions (e.g., high space velocity, high total pressure).

  12. Performance testing with a gas-liquid-solid system in a mechanically-stirred reactor: The Fischer-Tropsch synthesis

    SciTech Connect

    Donnelly, T.J.; Satterfield, C.N.

    1987-01-01

    Careful attention to reactor operating procedures and methods of product trapping and analysis is required to obtain accurate and reliable data on selectivity and kinetics when a wide variety of products are formed. Useful methods are discussed in detail. The focus of attention is on use of iron-based Fischer-Tropsch catalysts studied in a well-mixed slurry reactor, but many of the findings apply to other catalysts and reactor systems used for Fischer-Tropsch synthesis or to other reactions in which a complex mixture of products is formed. Some apparent discrepancies in the literature regarding catalyst activity and selectivity in Fischer-Tropsch synthesis are explained by analysis of the pertinent experimental systems. 50 refs., 4 figs., 2 tabs.

  13. 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.

  14. 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.

  15. Nanoscale platinum and iron-cobalt catalysts deposited in microchannel microreactors for use in hydrogenation and dehydrogenation of cyclohexene, selective oxidation of carbon monoxide and Fischer-Tropsch process to higher alkanes

    NASA Astrophysics Data System (ADS)

    Zhao, Shihuai

    reactions of enormous commercial potential: Fischer-Tropsch (F-T) synthesis, and preferential oxidation of CO in fuel cell. An over 50% conversion of CO and 78% selectivity to propane in F-T synthesis has been achieved. Meanwhile, a 70% conversion of CO and 80% selectivity to CO2 in preferential oxidation is reached in the fuel cell feed gas reaction. Statistical modeling studies were done using a Central Composite Design (CCD) to achieve the optimal condition (temperature 158°C, CO: O2 ratio 1.77 and total flow rate 0.207 sccm) for preferential oxidation of CO in fuel cells.

  16. 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. PMID:15310958

  17. Development of improved iron Fischer-Tropsch catalysts. [Iron catalyst with nominal composition 100Fe/0. 3Cu/0. 8K

    SciTech Connect

    Bukur, D.B.

    1992-04-24

    Three tests (two fixed bed and one stirred tank slurry reactor) were completed during the reporting period. Also, the work on catalyst characterization by different techniques (atomic absorption, BET surface area and pore size distribution and x-ray powder diffraction).The performance of a precipitated iron catalyst with nominal composition lOOFe/0.3Cu/0.8K has been evaluated in two fixed bed reactor tests designated FB-0142 and FB-0352 following pretreatment with syngas (H{sub 2}/CO=0.67) at 280{degree}C, 3Nl/g-cat/h and atomspheric pressure for 8 hours. Flow interruption occurred in the first test (FB-0142) at about 72h on stream, and the second test (FB-0352) was to assess any potential adverse effects of this flow interruption on performance of the catalyst. The catalyst was tested at 250{degree}C, 200 psig, 2Nl/g-cat/h using syngas of the same composition as that employed during the pretreatment. Initial conversions in both tests were high (about 84%) but the catalyst deactivated fairly rapidly. The (H{sub 2} + CO) conversion at the end of the first test (120h on stream) was about 52%, whereas the syngas conversion at the end of the second test (150h) was about 55%, indicating that the brief flow interruption during test FB-0142 had resulted in higher deactivation rate. Hydrocarbon selectivities in both tests were similar and their average values werr: (CH{sub 4})=4.7, (C{sub 2}{minus}C{sub 4})=19.5, (C{sub 5}{minus}C{sub 11})=25.3 and C{sub 12}{sup +}=50.5 wt%.

  18. Bulk and surface structure of a Ni Fe/Al2O3 catalyst for Fischer-Tropsch synthesis studied by Mössbauer, infrared spectroscopy and magnetic methods

    NASA Astrophysics Data System (ADS)

    Boellaard, E.; van der Kraan, A. M.; Geus, J. W.

    1992-04-01

    Deposition precipitation of a stoichiometric nickel-ironcyanide complex onto an alumina support and subsequent calcination and reduction has resulted in the formation of a homogeneous metallic alloy which exhibits activity for Fischer-Tropsch synthesis. During hydrocarbon synthesis conditions only a fraction of the metallic phase is converted in a phase which is most likely a thermally unstable (nickel-)iron carbide.

  19. 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.

  20. 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.

  1. Technology development for iron fischer-tropsch catalysis

    SciTech Connect

    Davis, B.H.

    1997-05-14

    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 5 catalysts synthesized in this program for activity, selectivity and aging characteristics.

  2. Product evaluation of Fischer-Tropsch derived fuels

    SciTech Connect

    Marano, J.J.; Rogers, S.; Choi, G.N.; Kramer, S.J.

    1994-12-31

    The Clean Air Act Amendments (CAAA) of 1990 have placed stringent requirements on the quality of transportation fuels. Most petroleum refiners are scrambling to meet provisions of the Amendments to be implemented between 1995 and 2000. These requirements will also have significant implications for the production of alternative fuels. These have been examined for Fischer-Tropsch (F-T) derived fuels. This analysis was conducted in conjunction with the U.S. Department of Energy (DOE) sponsored project, Baseline Design/Economics for Advanced Fischer-Tropsch Technology, conducted by Bechtel and Amoco. The goal of this study was to develop a baseline design for indirect liquefaction of Illinois No. 6 coal using gasification, syngas conversion in slurry reactors with iron catalysts, and conventional refinery upgrading of the F-T derived hydrocarbon liquids. One alternative case using ZSM-5 upgrading technology was also considered. This study included complete capital and operating cost estimates for the processes. To perform economic analyses for the different design cases, the products from the liquefaction plant had to be valued relative to conventional transportation fuels. This task was accomplished by developing a Linear Programming (LP) model for a typical midwest refinery, and then feeding the F-T liquids to the refinery. In this way, the breakeven value determined for these materials is indicative of the price they could command if available in the marketplace. Inputs to the LP model include: refinery size, configuration, feedstocks, products, specifications, prices, and operating and capital recovery costs. The model was set up to be representative of conditions anticipated for the turn of the century. This required inclusion of fuel specifications from the CAAA of 1990 which have or will come into force by the year 2000.

  3. 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.

  4. Development of a stable cobalt-ruthenium Fischer-Tropsch catalyst. Technical progress report No. 11, April 1, 1992--June 30, 1992

    SciTech Connect

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

    1992-12-31

    Four new catalysts were prepared and screened during this reporting period. They were compared to a reference Co-based catalyst (TC 211) which was developed under a previous DOE contract No. AC22-84PC10028. The reference catalyst was prepared on a special steamed and acid-washed Y zeolite support. The four new catalysts were prepared on a commercial product which is a specially-prepared Y zeolite. A special solvent was used to impregnate contract to a division of Union Carbide which is now part of UOP. Catalyst TC 211 was prepared by impregnating metals onto a laboratory steamed and acid-washed Y zeolite. A special impregnation solvent was used. At similar operating conditions, the four catalysts tested were less active and more selective to methane than the reference catalyst. A temperature change was made in the testing of these four catalysts (condition 1 to condition 2) to obtain conversions comparable to that obtained with the reference catalyst. Higher methane selectivity was noted for these catalysts when comparisons were made at similar conversion levels. When the new catalysts were evaluated at different conversions resulting from changes in feed rate at the same temperature (condition 2 to condition 3) high methane selectivity persisted. Thus these catalysts did not exhibit the expected lower methane selectivity at higher conversion. The four catalysts tested were intrinsically more selective to methane than the reference catalyst. They were, however, similar to the reference catalyst in their low selectivity to alcohols (Table 5). Of the four catalysts, catalyst 6531-161 which contained ruthenium appeared to be the most selective for methane.

  5. Fischer-Tropsch slurry phase process variations to understand wax formations: Quarterly report for period, April 1, 1988-June 30, 1988

    SciTech Connect

    Donnelly, T.; Satterfield, C.N.

    1988-01-01

    A precipitated iron Ruhrchemie catalyst formerly used at the SASOL operations in South Africa and similar to that currently used was studied in a continuous-flow well-stirred slurry reactor at 232/degree/ C to 263/degree/C, 2.16 to 2.98 MPa, H/sub 2//CO feed ratios of 0.70 to 0.78 and syngas conversions of 15 to 65%. The carbon number distribution of the hydrocarbon products followed a Schulz-Flory distribution with two values of ..cap alpha... These distributions are compared to those of several other iron catalysts. Selectivity to 1-alkenes increased with temperature. Secondary hydrogenation of 1-alkenes is shown to be a major pathway to n-alkanes. Activity for the water-gas shift is much less than that for other iron catalysts. 31 refs., 17 figs., 7 tabs.

  6. Design of generic coal conversion facilities: Indirect coal liquefaction, Fischer-Tropsch synthesis

    SciTech Connect

    Not Available

    1991-10-01

    A comprehensive review of Fischer-Tropsch (F-T) technology, including fixed, fluidized, and bubble column reactors, was undertaken in order to develop an information base before initiating the design of the Fischer-Tropsch indirect liquefaction PDU as a part of the Generic Coal Conversion Facilities to be built at the Pittsburgh Energy Technology Center (PETC). The pilot plant will include a fixed bed and slurry bubble column reactor for the F-T mode of operation. The review encompasses current status of both these technologies, their key variables, catalyst development, future directions, and potential improvement areas. However, more emphasis has been placed on the slurry bubble column reactor since this route is likely to be the preferred technology for commercialization, offering process advantages and, therefore, better economics than fixed and fluidized bed approaches.

  7. The role of Fischer Tropsch catalysis in the origin of methane-rich Titan

    NASA Astrophysics Data System (ADS)

    Sekine, Yasuhito; Sugita, Seiji; Shido, Takafumi; Yamamoto, Takashi; Iwasawa, Yasuhiro; Kadono, Toshihiko; Matsui, Takafumi

    2005-11-01

    Fischer-Tropsch catalysis, which converts CO and H 2 into CH 4 on the surface of iron catalyst, has been proposed to produce the CH 4 on Titan during its formation process in a circum-planetary subnebula. However, Fischer-Tropsch reaction rate under the conditions of subnebula have not been measured quantitatively yet. In this study, we conduct laboratory experiments to determine CH 4 formation rate and also conduct theoretical calculation of clathrate formation to clarify the significance of Fischer-Tropsch catalysis in a subnebula. Our experimental result indicates that the range of conditions where Fischer-Tropsch catalysis proceeds efficiently is narrow ( T˜500-600 K) in a subnebula because the catalysts are poisoned at temperatures above 600 K under the condition of subnebula (i.e., H 2/CO = 1000). This suggests that an entire subnebula may not become rich in CH 4 but rather that only limited region of a subnebula may enriched in CH 4 (i.e., CH 4-rich band formation). Our experimental result also suggests that both CO and CO 2 are converted into CH 4 within time significantly shorter than the lifetime of the solar nebula at the optimal temperatures around 550 K. The calculation result of clathration shows that CO 2-rich satellitesimals are formed in the catalytically inactive outer region of subnebula. In the catalytically active inner region, CH 4-rich satellitesimals are formed. The resulting CH 4-rich satellitesimals formed in this region play an important role in the origin of CH 4 on Titan. When our experimental data are applied to a high-pressure model for subnebula evolution, it would predict that there should be CO 2 underneath the Iapetus subsurface and no thick CO 2 ice layer on Titan's icy crust. Such surface and subsurface composition, which may be observed by Cassini-Huygens mission, would provide crucial information on the origin of icy satellites.

  8. Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 8, July 1, 1992--September 30, 1992

    SciTech Connect

    Marcelin, G.

    1993-07-07

    The initial work on the synthesis of MTBE during CO hydrogenation shows that MTBE cannot be formed directly on metal sites and likely requires the presence of an acid site. However, MTBE can be made successfully when an acid site, provided by the zeolites, is present in the vicinity of the methanol-synthesis metal sites. When i-butylene was added during CO hydrogenation over a composite catalyst consisting of Li-Pd/SiO{sub 2} and a hydrogen-zeolite, MTBE was formed in measurable amounts. The major by-product of this reaction scheme was isobutane and the dimer of i-butylene. In general, ZSM-5 was found to be superior to LZ210-12 HY zeolite. CO hydrogenation over a bifunctional PdNaY catalyst shows that branched hydrocarbons as well as MEOH can be made successfully at the same time. Addition of i-butylene over this catalyst only (i.e. without other zeolite) results in the formation of trace amounts of MTBE.

  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. Upgrading of light Fischer-Tropsch products

    SciTech Connect

    Shah, P.P.

    1990-11-30

    The upgrading of Fischer-Tropsch (F-T) light ends was studied at UOP in a program sponsored by the Pittsburgh Energy Technology Center of the US Department of Energy. The goal of the program was to increase the overall yield of marketable transportation fuels from the F-T upgrading complex by focusing on liquefied petroleum gas (LPG) and naphtha. An overview of the entire light-ends program is presented in this paper. Although this contract is specifically concerned with light products (C{sub 3}-C{sub 11}), a separate DOE-sponsored program at UOP investigated the characterization and upgrading of the heavy end of the F-T product spectrum: F-T wax. An economic analysis of the light and heavy ends upgrading was performed to evaluate the conversion of F-T products to marketable transportation fuels. 9 refs., 7 figs., 9 tabs.

  12. Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 9, October 1, 1992--December 31, 1992

    SciTech Connect

    Marcelin, G.

    1993-06-30

    Figure 7 summarizes the carbon selectivities observed towards the main products. During Period IV, the main products observed were the heavy hydrocarbons, with selectivity for MTBE being less than 3--5%. The only time that high MTBE selectivity was noted was during period III, when the i-butylene feed was shut-off. The large amounts of heavy products and the low selectivity to MTBE were surprising in view of our previous experiments in the gas phase and the high methanol-to-i-butylene ratio used in these runs. In the gas-phase and with methanol/i-butylene = 0.5, over 95% selectivity to MTBE was observed with this catalyst at this temperature. The higher level of methanol used here would be expected to further improve the MTBE selectivity. Perhaps one reason for the poor MTBE selectivity relates to the relative solubilities of the reactants in the Synfluid changing the effective methanol/i-butylene ratio. Figure 8 shows the relative molar concentration of i-butylene during Period III. At 180 minutes, the gas supply of that reactant was shut-off, yet the analyses show that i-butylene continued to elute from the reactor for at least an additional 2 hours. It seems reasonable that the i-butylene is highly soluble in the Synfluid since they are both nonpolar hydrocarbons. Likewise, one would expect the methanol to not be quite as soluble and thus the methanol/i-butylene ratio in the liquid medium may be very low, favoring the oligomerization of i-butylene. Indeed, the only time that MTBE selectivity was high was after the i-butylene supply was shut-off. We intend to quantify these solubilities in future experiments.

  13. Multiple and antagonistic effects of water on intrinsic physical properties of model Fischer-Tropsch cobalt catalysts evidenced by in situ X-ray diffraction.

    PubMed

    Scalbert, J; Legens, C; Clémençon, I; Taleb, A-L; Sorbier, L; Diehl, F

    2014-07-25

    Direct evidence for cobalt oxidation under water treatment at 230 °C was revealed using in situ XRD, even in the presence of small amounts of H2. Oxidation kinetics was proved to be particle size dependent. The resulting Co3O4 showed a firmly smaller coherent domain size than the initial calcined catalyst. PMID:24911967

  14. 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.

  15. Fine details on the selectivity and kinetics of the Fischer-Tropsch synthesis over precipitated cobalt catalysts by combination of quantitative gas chromatography and modelling

    SciTech Connect

    Hurlbut, R.S.; Puskas, I.; Schumacher, D.J.

    1995-12-01

    A combination of quantitative GC (for the lighter products) and calculations by the ASF model (for the heavy products) provided instantaneous product determinations for studying the influence of feed composition, pressure space velocity and temperature on the chain growth probability of the reaction over cobalt catalysts in a plug flow reactor. Material balances were not always 100%, the ASF model often underestimated the heavy products. The results will be presented in graphs and tables. Two of the findings are highlighted here: (1) Inert species were found to impede the reaction rate and the chain growth. (2) The rate was found to be a linear function of the temperature over a wide conversion range. These and other results attest to a multiplicity of the chain growth probability and to diffusional limitations of the rate.

  16. 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.

  17. Process for upgrading wax from Fischer-Tropsch synthesis

    SciTech Connect

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

    1987-08-04

    A processor is described for converting synthesis gas to liquid hydrocarbons comprising the steps of: (a) charging the synthesis gas to a Fischer-Tropsch synthesis conversion zone containing a catalyst providing CO reducing characteristics to produce a waxy hydrocarbon liquid; (b) separating hydrocarbon wax from the waxy liquid; (c) catalytically cracking the wax in a fluidized bed of acid crystalline zeolite at cracking temperature under process conditions requiring a supply of heat to effect cracking, producing olefinic liquid hydrocarbon crackate in the gasoline and distillate boiling range along with olefinic light gas; (d) recovering distillate range hydrocarbons from the liquid crackate; (e) further converting the olefinic gasoline range hydrocarbon crackate and olefinic light gas under oligomerization conditions in contact with a shape selective medium pore acid oligomerization catalyst to upgrade at least a portion of the olefinic crackate and olefinic light gas to distillate range hydrocarbon product and producing by-product light fuel gas; (f) separating the light fuel gas from step (e) and passing the light fuel gas to cracking step (c) to supply heat.

  18. Fine details on the selectivity and kinetics of the Fischer-Tropsch synthesis over precipitated cobalt catalysts by combination of quantitative gas chromatography and modelling

    SciTech Connect

    Hurlbut, R.S.; Puskas, I,; Schumacher, D.J.

    1995-12-31

    This report summarizes a part of our work carried out on the conversion of natural gas-derived synthesis gas to liquid fuels. Particularly, we were interested to find a catalyst which can convert dilute synthesis gas - such as obtainable from natural gas by partial oxidation with air - to predominantly liquid products at low pressures. For this purpose we needed to generate fundamental kinetic information on the controllability of the molecular weight distribution, which is defined by the chain growth probability of the reaction, because relatively little information is available on the subject. A wealth of information suggests, that with some exceptions in the low molecular weight regimes, the product distributions can be described by Anderson-Schulz-Flory (ASF) kinetics, using either a single chain growth probability, or separate chain growth probabilities for the light and heavy products. The causes of the {open_quotes}dual{close_quotes} chain growth probabilities still have not been defined. Three causes have been suggested which could account for the dual chain growth probabilities: (1) Differences in the catalytic sites; (2) transport-enhanced 1-olefin readsorption and incorporation into the heavy product fractions; and (3) operating characteristics of the reactor.

  19. 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

    2015-01-01

    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. PMID:25387082

  20. 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.

  1. Romania program targets methanol and Fischer-Tropsch research

    SciTech Connect

    Not Available

    1987-03-01

    Currently, the chemical organic industry, the petrochemical and engine fuels industry in Romania are entirely based on hydrocarbons from oil. To reduce the oil dependence of this sector and to ensure the stipulated growth rate of 8-9%, research and development programs have been set up with a view to the diversification of raw materials. In research on hydrocarbons from alcohol conversion, three process variants are known, i.e. olefins from methanol, gasolines from methanol and a combined gasolines and aromatic hydrocarbons from methanol. The Romanian process of methanol conversion to hydrocarbons is very flexible, with all the variants mentioned being carried out in the same plant by modifying the catalysts. In research on hydrocarbons from synthesis gas a modern process is being developed for gasification of brown coal in a fluidized bed, under pressure, in the presence of oxygen and water vapors. In the field of carbon oxide hydrogenation, studies have been carried out on selective Fischer-Tropsch processes in which the reaction products are high value hydrocarbon fractions.

  2. INTEGRATED FISCHER TROPSCH MODULAR PROCESS MODEL

    SciTech Connect

    Donna Post Guillen; Richard Boardman; Anastasia M. Gribik; Rick A. Wood; Robert A. Carrington

    2007-12-01

    With declining petroleum reserves, increased world demand, and unstable politics in some of the world’s richest oil producing regions, the capability for the U.S. to produce synthetic liquid fuels from domestic resources is critical to national security and economic stability. Coal, biomass and other carbonaceous materials can be converted to liquid fuels using several conversion processes. The leading candidate for large-scale conversion of coal to liquid fuels is the Fischer Tropsch (FT) process. Process configuration, component selection, and performance are interrelated and dependent on feed characteristics. This paper outlines a flexible modular approach to model an integrated FT process that utilizes a library of key component models, supporting kinetic data and materials and transport properties allowing rapid development of custom integrated plant models. The modular construction will permit rapid assessment of alternative designs and feed stocks. The modeling approach consists of three thrust areas, or “strands” – model/module development, integration of the model elements into an end to end integrated system model, and utilization of the model for plant design. Strand 1, model/module development, entails identifying, developing, and assembling a library of codes, user blocks, and data for FT process unit operations for a custom feedstock and plant description. Strand 2, integration development, provides the framework for linking these component and subsystem models to form an integrated FT plant simulation. Strand 3, plant design, includes testing and validation of the comprehensive model and performing design evaluation analyses.

  3. 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.

  4. 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%).

  5. Correlating Fischer-Tropsch activity to Ru nanoparticle surface structure as probed by high-energy X-ray diffraction.

    PubMed

    Quek, Xian-Yang; Filot, Ivo A W; Pestman, Robert; van Santen, Rutger A; Petkov, Valeri; Hensen, Emiel J M

    2014-06-01

    Synchrotron X-ray diffraction coupled to atomic pair distribution function analysis and Reverse Monte Carlo simulations is used to determine the atomic-scale structure of Ru nanoparticle catalysts for the Fischer-Tropsch reaction. The rate of CO hydrogenation strongly correlates with the abundance of surface atoms with coordination numbers of 10 and 11. DFT calculations confirm that CO dissociation proceeds with a low barrier on these Ru surface atom ensembles. PMID:24763733

  6. Ultrafine particles of iron in Fischer-Tropsch synthesis

    SciTech Connect

    Mahajan, D.; Pandya, K.

    1994-12-31

    Though direct combustion of natural gas is the most efficient use of this abundant, inexpensive, and cleaner fossil fuel, its potential to replace existing less efficient feedstocks for downstream processes is enormous. Direct conversion of methane to useful products under mild conditions is an ongoing area of research, and a few reported successes include higher hydrocarbons (C{sub 2}-C{sub 6}) synthesis on Pt at 250{degrees}C, Hg-catalyzed synthesis of methanol at 180{degrees}C, and acetic acid synthesis catalyzed by aqueous RhCl{sub 3} at 100{degrees}C. Since these approaches are in early stages of development, improvements in other known routes are of interest. Fischer-Tropsch (F-T) synthesis is an indirect route to catalytic production of liquid fuels from synthesis gas derived from carbonaceous sources. The process is still uneconomical for widespread use due to low space-time-yield (STY), low product selectivity, and catalyst intolerance to sulfur. To address these aspects, a few reports describe the use of ultrafine particle (UFP) catalysts in slurry-phase F-T synthesis, We recently reported that a commercially available unsupported UFP FeZO{sub 3} material (NANOCAT{trademark}) (Mean particle diameter (MPD) = 3 nm; surface area (SA) - 255 m{sup 2}/g) slurried in a C{sub 30} hydrocarbon solvent, after reduction at 280{degrees}C under CO, catalyzed conversion of balanced synthesis gas (H{sub 2}/CO = 2/1) at {>=} 220{degrees}C and {<=} 3 MPa. Described below are additional runs carried out to further scrutinize the Fe UFP system.

  7. 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

  8. 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

  9. Elementary steps in Fischer-Tropsch synthesis: CO bond scission, CO oxidation and surface carbiding on Co(0001)

    NASA Astrophysics Data System (ADS)

    Weststrate, C. J.; van Helden, P.; van de Loosdrecht, J.; Niemantsverdriet, J. W.

    2016-06-01

    Dissociation of CO on a Co(0001) surface is explored in the context of Fischer-Tropsch synthesis on cobalt catalysts. Experiments show that CO dissociation can occur on defect sites around 330 K, with an estimated barrier between 90 and 104 kJ mol- 1. Despite the ease of CO dissociation on defect sites, extensive carbon deposition onto the cobalt surface up to 0.33 ML requires a combination of high surface temperature and a relatively high CO pressure. Experimental data on the CO oxidation reaction indicate a high reaction barrier for the CO + O reaction, and it is argued that, due to the rather strong Co-O bond, (i) oxygen removal is the rate-limiting step during surface carbidization and (ii) in the context of Fischer-Tropsch synthesis, removal of surface oxygen rather than CO bond scission might be limiting the overall reaction rate.

  10. Fischer-Tropsch slurry phase process variations to understand wax formation

    SciTech Connect

    Satterfield, C.N.; Hanlon, R.T.; Matsumoto, D.K.; Donnelly, T.J.; Yates, I.C.

    1989-10-01

    Use of a slurry-type reactor with an iron catalyst for Fischer- Tropsch synthesis from low H{sub 2}/CO syngas offers the potential advantages of excellent temperature control, flexibility in catalyst addition and removal and internal water gas shift. The most important likely process variations were studied to determine how they affect product selectivity. A C-73 reduced fused magnetite was used as a base-line catalyst since it is mechanically rugged and resistant to process upsets, but several precipitated iron catalysts were also studied and the performances of the various catalysts are compared. We have also developed an improved method of analyzing product distribution data. Information is provided on changes in product distribution during start-up, effect of water content, and correlations of these with composition of the iron catalyst as determined by Mossbauer spectroscopy. Methods of reliable performance testing in a slurry reactor are discussed. 26 refs., 27 figs.

  11. 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.

  12. 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. PMID:24825772

  13. BASELINE DESIGN/ECONOMICS FOR ADVANCED FISCHER-TROPSCH TECHNOLOGY

    SciTech Connect

    1998-04-01

    Bechtel, along with Amoco as the main subcontractor, developed a Baseline design, two alternative designs, and computer process simulation models for indirect coal liquefaction based on advanced Fischer-Tropsch (F-T) technology for the U. S. Department of Energy's (DOE's) Federal Energy Technology Center (FETC).

  14. CHAIN-LIMITING OPERATION OF FISCHER-TROPSCH REACTOR

    SciTech Connect

    Apostolos A. Nikolopoulos; Santosh K. Gangwal

    2000-11-01

    The use of pulsing to limit the chain growth of the hydrocarbon products of the Fischer-Tropsch (FT) synthesis in order to maximize the yield of diesel-range (C{sub 10}-C{sub 20}) products was examined on three high-chain-growth-probability ({alpha} {ge} 0.9) FT catalysts. On a Co-ZrO{sub 2}/SiO{sub 2} FT synthesis catalyst the 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 the instantaneous selectivity to CH{sub 4}. An optimum set of H{sub 2} pulse parameters (pulse frequency and duration) is required for maximizing the yield of desirable diesel-range C{sub 10}-C{sub 20} products. On a high-{alpha} Fe/K/Cu/SiO{sub 2} FT synthesis catalyst H{sub 2} pulsing enhances the yield of C{sub 10}-C{sub 20} but at the same time decreases the catalyst activity (CO conversion) and increases the selectivity to CH{sub 4}. On the other hand, pulsing with CO also increases the yield of C{sub 10}-C{sub 20} but has no impact on the selectivity to CH{sub 4} or CO{sub 2} and decreases catalytic activity only moderately. In contrast to these catalysts, H{sub 2} pulsing on a high-{alpha} Ru/alumina FT synthesis catalyst has only minimal effect on activity and product distribution, showing enhanced activity towards methanation and water-gas-shift at the expense of FT synthesis. However, these observations are based on experiments performed at a significantly lower reaction pressure (ca. 26 atm) and higher reaction temperature (210-250 C) than those commonly used for supported-Ru FT catalysts (typically 100-1000 atm, 160-170 C).

  15. Recent developments in Sasol Fischer-Tropsch technology

    SciTech Connect

    Dry, M.E.

    1986-04-01

    When considering improvements in the Fischer-Tropsch (FT) route for producing liquid fuels from coal, it is important to bear in mind the relative costs of the various process steps. The advantage of a big improvement in the selectivity of the FT synthesis (an ideal case would be one which produces only gasoline and diesel fuel) is that this would lower the costs of both the product separation and the refinery sections, which, together account for 22% of the total, Obvious provisos, however, are that the cost of the catalyst should not be markedly increased and that its conversion activity should remain high; otherwise the gains in say the refinery would be negated by increased FT synthesis costs. Elimination of certain products do not necessarily improve the economics. If the FT process made no ethylene, the expensive cryogenic separation unit could be replaced by a cheaper process but this would not be a real gain as the market value of ethylene relative to that of liquid fuels justifies its recovery. A similar situation holds for the alcohols and ketones produced in the FT process. If these products were absent then the expensive process of first recovering them from the FT water and then refining them would significantly lower the overall costs. (Note that these products would have to be completely absent and not just lowered as the latter would have little impact on the economics of recovery as the volume of water to be processed would remain unchanged.) These low molecular mass alcohols and ketones, however, sell at high prices; and furthermore, the alcohols are valuable as gasoline octane boosters. Thus the production and recovery of these components are justified.

  16. 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).

  17. Recent developments in the application of nanomaterials to understanding molecular level processes in cobalt catalysed Fischer-Tropsch synthesis.

    PubMed

    Beaumont, S K

    2014-03-21

    This perspective offers an overview of using nanomaterials for understanding cobalt catalysed Fischer-Tropsch chemistry. Nanomaterials now afford unprecedented control of size, shape and structure at the nanometre scale. This makes them invaluable tools for studying heterogeneous catalysis. The Fischer-Tropsch reaction, especially using cobalt based catalysts, is a linchpin in many processes for utilising other feedstocks (via gasification) that have been envisaged as short/medium term replacements for crude oil. The underlying chemistry has therefore garnered considerable renewed interest. The current state of the art in mechanistic understanding is summarised and the application of nanomaterials to developing this further is explored. Several specific questions, to which nanomaterials have already contributed answers, are addressed: how do nanomaterials contribute to our understanding of cobalt particle size effects, reducibility, and the effect of support porosity and how do precious metal promoters operate in cobalt catalysed Fischer-Tropsch chemistry? Future possible uses for nanomaterials in studying this field are also identified. PMID:24487570

  18. Design and performance of a high-pressure Fischer-Tropsch fluidized bed reactor

    SciTech Connect

    Weimer, A.W.; Quarderer, G.J.; Cochran, G.A.; Conway, M.M. )

    1988-01-01

    A 900 kg/day, CO/H/sub 2/, high-pressure, fluidized bed, pilot reactor was designed from first principles to achieve high reactant conversions and heat removal rates for the Fischer-Tropsch (F-T) synthesis of liquefied petroleum gases (LPG's). Suppressed bubble growth at high pressure allowed high reactant conversions which nearly matched those obtained at identical conditions in a lab scale fixed bed reactor. For GHSV approximately 1400 hr/sup -1/ and T = 658 {Kappa} at P approximately 7000 {kappa}Pa, reactant conversion exceeded 75%. The reactor heat removal capability exceeded twice design performance with the fluidized bed easily operating under thermally stable conditions. The fluidized catalyst was a potassium promoted, molybdenum on carbon (Mo/{Kappa}/C) catalyst which did not produce any detrimental waxy products. Long catalyst lifetimes of 1000 hrs on steam between regenerations allowed the fluidized bed to be operated in a batch mode.

  19. Compression-ignition fuel properties of Fischer-Tropsch syncrude

    SciTech Connect

    Suppes, G.J.; Terry, J.G.; Burkhart, M.L.; Cupps, M.P.

    1998-05-01

    Fischer-Tropsch conversion of natural gas to liquid hydrocarbon fuel typically includes Fischer-Tropsch synthesis followed by refining (hydrocracking and distillation) of the syncrude into mostly diesel or kerosene with some naphtha (a feedstock for gasoline production). Refining is assumed necessary, possibly overlooking the exception fuel qualities of syncrude for more direct utilization as a compression-ignition (CI) fuel. This paper evaluates cetane number, viscosity, cloud-point, and pour-point properties of syncrude and blends of syncrude with blend stocks such as ethanol and diethyl ether. The results show that blends comprised primarily of syncrude are potentially good CI fuels, with pour-point temperature depression being the largest development obstacle. The resulting blends may provide a much-needed and affordable alternative CI fuel. Particularly good market opportunities exist with Environmental Policy Act (EPACT) applications.

  20. 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

  1. Emissions from Trucks using Fischer-Tropsch Diesel Fuel

    SciTech Connect

    Paul Norton; Keith Vertin; Brent Bailey; Nigel N. Clark; Donald W. Lyons; Stephen Goguen; James Eberhardt

    1998-10-19

    The Fischer-Tropsch (F-T) catalytic conversion process can be used to synthesize diesel fuels from a variety of feedstocks, including coal, natural gas and biomass. Synthetic diesel fuels can have very low sulfur and aromatic content, and excellent autoignition characteristics. Moreover, Fischer-Tropsch diesel fuels may also be economically competitive with California B- diesel fuel if produced in large volumes. overview of Fischer-Tropsch diesel fuel production and engine emissions testing is presented. Previous engine laboratory tests indicate that F-T diesel is a promising alternative fuel because it can be used in unmodified diesel engines, and substantial exhaust emissions reductions can be realized. The authors have performed preliminary tests to assess the real-world performance of F-T diesel fuels in heavy-duty trucks. Seven White-GMC Class 8 trucks equipped with Caterpillar 10.3 liter engines were tested using F-T diesel fuel. Vehicle emissions tests were performed using West Virginia University's unique transportable chassis dynamometer. The trucks were found to perform adequately on neat F-T diesel fuel. Compared to a California diesel fuel baseline, neat F-T diesel fuel emitted about 12% lower oxides of nitrogen (NOx) and 24% lower particulate matter over a five-mile driving cycle.

  2. 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

  3. 40 CFR 721.10103 - Naphtha (Fischer-Tropsch), C4-11-alkane, branched and linear.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  4. 40 CFR 721.10103 - Naphtha (Fischer-Tropsch), C4-11-alkane, branched and linear.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  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...

  8. 40 CFR 721.10178 - Distillates (Fischer-Tropsch), hydroisomerized middle, C10-13-branched alkane fraction.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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),...

  9. An experimental study on Fischer-Tropsch catalysis: Implications for impact phenomena and nebular chemistry

    NASA Astrophysics Data System (ADS)

    Sekine, Yasuhito; Sugita, Seiji; Shido, Takafumi; Yamamoto, Takashi; Iwasawa, Yasuhiro; Kadono, Toshihiko; Matsui, Takafumi

    2006-05-01

    Fischer-Tropsch catalysis, by which CO and H2 are converted to CH4 on the surface of transition metals, has been considered to be one of the most important chemical reactions in many planetary processes, such as the formation of the solar and circumplanetary nebulae, the expansion of vapor clouds induced by cometary impacts, and the atmospheric re-entry of vapor condensate due to asteroidal impacts. However, few quantitative experimental studies have been conducted for the catalytic reaction under conditions relevant to these planetary processes. In this study, we conduct Fischer-Tropsch catalytic experiments at low pressures (1.3 × 10-4 bar ≤ P ≤ 5.3 × 10 -1 bar) over a wide range of H2/CO ratios (0.25-1000) using pure iron, pure nickel, and iron-nickel alloys. We analyze what gas species are produced and measure the CH4 formation rate. Our results indicate that the CH4 formation rate for iron catalysts strongly depends on both pressure and the H2/CO ratio, and that nickel is a more efficient catalyst at lower pressures and lower H2/CO ratios. This difference in catalytic properties between iron and nickel may come from the reaction steps concerning disproportionation of CO, hydrogenation of surface carbon, and the poisoning of the catalyst. These results suggest that nickel is important in the atmospheric re-entry of impact condensate, while iron is efficient in circumplanetary subnebulae. Our results also indicate that previous numerical models of iron catalysis based on experimental data at 1 bar considerably overestimate CH4 formation efficiency at lower pressures, such as the solar nebula and the atmospheric re-entry of impact condensate.

  10. 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.

  11. Fischer-Tropsch Synthesis: Characterization and Reaction Testing of Cobalt Carbide

    SciTech Connect

    Khalid S.; Mohandas J.C.; Gnanamani M.K.; Jacobs G.; Ma W.; Ji Y.; Davis B.H.

    2011-08-15

    Hydrogenation of carbon monoxide was investigated for cobalt carbide synthesized from Co{sub 3}O{sub 4} by CO carburization in a fixed-bed reactor. The cobalt carbide synthesized was characterized by BET surface area, X-ray diffraction, scanning electron microscopy, X-ray absorption near edge spectroscopy, and extended X-ray absorption fine structure spectroscopy. The catalysts were tested in the slurry phase using a continuously stirred tank reactor at P = 2.0 MPa, H{sub 2}/CO = 2:1 in the temperature range of 493-523 K, and with space velocities varying from 1 to 3 Nl h{sup -1} g{sub cat}{sup -1}. The results strongly suggest that a fraction of cobalt converts to a form with greater metallic character under the conditions employed. This was more pronounced on a Fischer-Tropsch synthesis run conducted at a higher temperature (523 versus 493 K).

  12. 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.

  13. Catalytic conversion of olefinic fischer tropsch light oil to heavier hydrocarbons

    SciTech Connect

    Owen, H.; Tabak, S. A.; Wright, B. S.

    1985-05-28

    A process for converting synthol light oil product of Fischer-Tropsch synthesis to heavy distillate comprising the steps of contacting the light oil at elevated temperature and pressure with acid zeolite conversion catalyst to oligomerize olefins and convert oxygenated hydrocarbons contained in the light oil thereby providing an effluent containing light heavy distillate range hydrocarbon, hydrocarbon vapor and byproduct water; flashing and separating the effluent to recover a heavy distillate-rich liquid phase and a light hydrocarbon-rich vapor phase containing byproduct water; condensing the vapor phase to provide a liquid hydrocarbon recycle stream; removing byproduct water from the recycle stream; combining the light oil with the pressurized recycle stream as heat sink to prevent excessive reaction temperature during catalytic conversion.

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

    PubMed

    Maitlis, Peter M; Zanotti, Valerio

    2009-04-01

    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

  15. Technology development for cobalt F-T catalysts. Topical report No.3, Zirconia promotion of Fischer-Tropsch cobalt catalysts: Behavior in fixed-bed and slurry bubble column reactors

    SciTech Connect

    Oukaci, R.; Marcelin, G.; Goodwin, J.G. Jr.

    1995-01-17

    A series of cobalt-based F-T catalysts supported on alumina and silica were prepared with different loadings of Zr and different sequences of impregnation of Co and Zr. All catalysts were extensively characterized by different methods. The catalysts were evaluated in terms of their activity and selectivity both in fixed bed and slurry bubble column reactors. Addition of ZrO{sub 2} to both Co/SiO{sub 2} and Co/Al{sub 2}O{sub 3} catalysts resulted in at least a twofold increase in the catalyst activity for F-T synthesis in the fixed bed reactor. In the slurry bubble column reactor, a similar promotion effect was observed for the SiO{sub 2}-supported catalysts, while the addition of Zr to a cobalt/alumina catalyst had a less significant effect.

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. Fischer-Tropsch synthesis in near-critical n-hexane: Pressure-tuning effects

    SciTech Connect

    Bochniak, D.J.; Subramaniam, B.

    1998-08-01

    For Fe-catalyzed Fischer-Tropsch (FT) synthesis with near-critical n-hexane (P{sub c} = 29.7 bar; T{sub c} = 233.7 C) as the reaction medium, isothermal pressure tuning from 1.2--2.4 P{sub c} (for n-hexane) at the reaction temperature (240 C) significantly changes syngas conversion and product selectivity. For fixed feed rates of syngas (H{sub 2}/CO = 0.5; 50 std. cm{sup 3}/g catalyst) and n-hexane (1 mL/min), syngas conversion attains a steady state at all pressures, increasing roughly threefold in this pressure range. Effective rate constants, estimated assuming a first-order dependence of syngas conversion on hydrogen, reveal that the catalyst effectiveness increases with pressure implying the alleviation of pore-diffusion limitations. Pore accessibilities increase at higher pressures because the extraction of heavier hydrocarbons from the catalyst pores is enhanced by the liquid-like densities, yet better-than-liquid transport properties, of n-hexane. This explanation is consistent with the single {alpha} (= 0.78) Anderson-Schulz-Flory product distribution, the constant chain termination probability, and the higher primary product (1-olefin) selectivities ({approximately}80%) observed at the higher pressures. Results indicate that the pressure tunability of the density and transport properties of near-critical reaction media offers a powerful tool to optimize catalyst activity and product selectivity during FT reactions on supported catalysts.

  3. Upgrading oxygenated Fischer-Tropsch derivatives and one-step direct synthesis of ethyl acetate from ethanol - examples of the desirability of research on simple chemical compounds transformations.

    PubMed

    Klimkiewicz, Roman

    2014-01-01

    Oxygenates formed as by-products of Fischer-Tropsch syntheses can be transformed into other Fischer-Tropsch derived oxygenates instead of treating them as unwanted chemicals. One-step direct synthesis of ethyl acetate from ethanol is feasible with the use of some heterogeneous catalysts. Despite their apparent simplicity, both transformations are discussed as targeted fields of research. Furthermore, the two concepts are justified due to the environmental protection. Arguments regarding the Fischer-Tropsch process are focused on the opportunities of the utilization of undesirable by-products. The effective striving for their utilization can make the oxygenates the targeted products of this process. Arguments regarding the one-step direct synthesis of ethyl acetate underline the environmental protection and sustainability as a less waste-generating method but, above all, highlight the possibility of reducing the glycerol overproduction problem. The production of ethyl acetate from bioethanol and then transesterification of fats and oils with the use of ethyl acetate allows managing all the renewable raw materials. Thus, the process enables the biosynthesis of biodiesel without glycerine by-product and potentially would result in the increase in the demand for ethyl acetate. Graphical Abstract. PMID:25648719

  4. 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

  5. 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.

  6. Studies of the Fischer-Tropsch reaction on Co(0001)

    NASA Astrophysics Data System (ADS)

    Geerlings, J. J. C.; Zonnevylle, M. C.; de Groot, C. P. M.

    1991-01-01

    The Fischer-Tropsch reaction has been studied over Co(0001) in the temperature range between 220 and 300 °C at 1 bar total pressure and an H 2 : CO ratio of 2 : 1. It was found that the activation energies for methane, ethane and propane formation are equ which suggests similar rate determining steps. We propose that α-hydrogenation of a C nH 2 n+1 surface species is rate limiting. Olefins are formed via β-dehydrogenation of the same species. The olefins take part in a consecutive reaction and are finally converted to paraffins. The product distribution was found to follow Schulz-Flory kinetics with a chain growth probability of 0.2 at 250 °C. Post-reaction spectroscopy with EELS and Auger indicated the presence of CO and CH x ( x = 1, 2, 3) fragments on the surface.

  7. 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.

  8. A new synthesis of carbon encapsulated Fe5C2 nanoparticles for high-temperature Fischer-Tropsch synthesis

    NASA Astrophysics Data System (ADS)

    Hong, Seok Yong; Chun, Dong Hyun; Yang, Jung-Il; Jung, Heon; Lee, Ho-Tae; Hong, Sungjun; Jang, Sanha; Lim, Jung Tae; Kim, Chul Sung; Park, Ji Chan

    2015-10-01

    Using a simple thermal treatment under a CO flow, uniform micrometer-sized iron oxalate dihydrate cubes prepared by hydrothermal reaction were transformed into Fe5C2@C nanoparticles to form a mesoporous framework; the final structure was successfully applied to the high-temperature Fischer-Tropsch reaction and it showed high activity (CO conversion = 96%, FTY = 1.5 × 10-4 molCO gFe-1 s-1) and stability.Using a simple thermal treatment under a CO flow, uniform micrometer-sized iron oxalate dihydrate cubes prepared by hydrothermal reaction were transformed into Fe5C2@C nanoparticles to form a mesoporous framework; the final structure was successfully applied to the high-temperature Fischer-Tropsch reaction and it showed high activity (CO conversion = 96%, FTY = 1.5 × 10-4 molCO gFe-1 s-1) and stability. Electronic supplementary information (ESI) available: Details of experimental procedures, SEM images of FeNi and FeCo oxalate hydrate particles, particle size and pore size distributions, FT activity and selectivity, hydrocarbon product distribution, ASF plot, and Mössbauer parameters of the Fe5C2@C catalyst. See DOI: 10.1039/c5nr05787f

  9. Diesel production from Fischer-Tropsch: the past, the present, and new concepts

    SciTech Connect

    Dieter Leckel

    2009-05-15

    Fischer-Tropsch synthesis is technically classified into two categories, the high-temperature Fischer-Tropsch (HTFT) and the low-temperature Fischer-Tropsch (LTFT) processes. The criterion for this classification is the operating temperature of the synthesis, which ranges between 310-340{sup o}C for the HTFT process and 210-260{sup o}C for the LTFT process. A Fischer-Tropsch facility can be divided into roughly three sections, synthesis gas (syngas) generation, FT synthesis, and refining of the synthetic crude (syncrude). Fischer-Tropsch refineries differ regarding the product upgrading, and both transportation fuels and chemicals can be produced. Regarding the FT refinery history, the configuration of each refinery also reflects the requirements of the fuel specification at that time. This paper gives a condensed overview of how Fischer-Tropsch facilities changed during the last 70 years and focuses in particular on the diesel fuel produced. Some conceptual flow schemes are additionally presented with emphasis on the combined upgrading of the high boiling part of the FT product spectrum with liquids derived from coal pyrolysis. 52 refs., 14 figs., 12 tabs.

  10. Toward an understanding of methane selectivity in the Fischer-Tropsch process

    NASA Astrophysics Data System (ADS)

    Psarras, Peter C.

    The purpose of this research is to elucidate a better understanding of the conditions relevant to methane selectivity in the Fischer-Tropsch (FT) process. The development of more efficient FT catalysts can result in great commercial profit. The industrially relevant FT process has long been hampered by the production of methane. Nearly 60 percent of FT capital is devoted to the removal of methane and purification of feed-stock gases through steam-reforming. Naturally, a more efficient FT catalyst would need to have a reasonable balance between catalytic activity and suppression of methane formation (low methane selectivity). Though a significant amount of work has been devoted to understanding the mechanisms involved in methane selectivity, the exact mechanism is still not well understood. Density functional theory (DFT) methods provide an opportunity to explore the FT catalytic process at the molecular level. This work represents a combination of various DFT approaches in an attempt to gather new insight on the conditions relevant to methane selectivity. A thorough understanding of the electronic environment involved in the surface-adsorbate interaction is necessary to the advancement of more efficient Fischer-Tropsch catalysts. This study investigates the promotive effect of four late transition metals (Cu, Ag, Au and Pd) on three FT catalytic surfaces (Fe, Co and Ni). The purpose of this research is to examine the surface-adsorbate interaction from two perspectives: 1) interactions occurring between FT precursors and small, bimetallic surface analogs (clusters), and 2) plane-wave calculations of the interactions between FT precursors and simulated bulk surfaces. Our results suggest that promising candidates for the reduction of FT methane selectivity include Au and Pd on Ni, Au and Ag on Co, and Cu, Ag, and Pd on Fe. Additionally, cluster models were susceptible to effects not encountered in the plane-wave approach. Thermodynamic trends can be made more

  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. 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. PMID:24616239

  13. 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.

  14. Technology developments to enable the commercial viability of the Fischer-Tropsch process

    SciTech Connect

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

    1996-12-31

    The well established Fischer-Tropsch (F-T) technologies for catalytic conversion of coal-based synthesis gas to hydrocarbon liquid and wax products have been practiced for many years in locations (such as South Africa) where political reasons have forced the production operations even though unusual commercial competitive economics would not be sufficiently attractive to justify the process. This has generated a substantive technical experience with F-T technologies and products that is currently being adapted to use with syngas produced from coal, natural gas, and other sources of hydrocarbon gas in many niche markets over the world. Energy International, one of the Williams Companies, is currently developing this process for use in near-term commercial applications based on improvements in catalyst and process design that can substantially reduce the economic cost of producing hydrocarbon fuels, chemicals, and waxes. This improved economic basis for use of F-T technology derives from on-going efforts supported by the Department of Energy`s Pittsburgh Energy Technology Center and Energy International. In important laboratory developments and evaluations, the use of cobalt catalysts has been shown to have the potential for greater products yields and better controls on the reactor operating conditions so as to produce the more desirable and economically effective sets of quality products. This presentation will review the technical improvements achieved with the new catalysts and the impact on the economic viability of the F-T process.

  15. 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.

  16. Studies on the Role of Nitrogen in the Feed for Fischer-Tropsch Synthesis Under Fixed-Bed Reactor System.

    PubMed

    Hong, Gi Hoon; Jung, Jae-Sun; Kim, Na-Young; Lee, Sang Yong; Moon, Dong Ju

    2016-02-01

    In this study, Co/Al203 catalyst for Fischer-Tropsch synthesis was prepared via slurry impregnation method and the catalyst was characterized by various techniques such as TPR, XRD, TGA and N2 physisorption. To dissolve the wax, after-reaction catalyst was dewaxed using n-Hexane at 60 *C. The experiments were performed in a bench-scale fixed-bed reactor, under the reaction condition of 230 degrees C, 20 bar and feed volume ratio of H2:CO:N2 = 2:1:0.5-1.5. The methane selectivity and the ratio of olefin to paraffin among C2-C4 hydrocarbons were increased with higher contents of nitrogen in feed gas which result in higher partial pressure ratio of H2 to CO, and also affect methane selectivity which has a significant role in increased CO conversion. PMID:27433695

  17. Comparative study of oil-slurry process to fixed-bed process in the Fischer-Tropsch synthesis

    SciTech Connect

    Sakai, T.; Kunugi, T.

    1982-01-01

    Differences between the oil-slurry process and the fixed-bed process on catalyst activity and C/sub 1/-C/sub 4/ product selectivity in the Fischer-Tropsch systhesis are described for a precipitated iron catalyst at reaction temperatures of 200 to 250/sup 0/C. Other reaction conditions used were those usually used for the two processes but were not the same for both processes. The data indicated that the catalyst activity is due to the presence of metallic iron suppresses the formation of CH/sub 4/ and favors the C/sub 3/ and C/sub 4/ hydrocarbon formation, and the experimental data preclude the formation of iron carbide for the oil-slurry process. An activation energy of 79.1kJ/mole was obtained at temperatures of 230 to 242/sup 0/C. (BLM)

  18. 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.

  19. Fischer-Tropsch Synthesis: Assessment of the Ripening of Cobalt Clusters and Mixing Between Co and Ru Promoter via Oxidation-Reduction-Cycles over Lower Co-Loaded Ru-Co/A12O3 Catalysts

    SciTech Connect

    Jacobs,G.; Sarkar, A.; Ji, Y.; Luo, M.; Dozier, A.; Davis, B.

    2008-01-01

    A 2% Ru-promoted 15% Co/Al2O3 catalyst was tested after reduction and after being subjected to oxidation-reduction cycles. The catalysts were characterized over four oxidation-reduction cycles by XANES/EXAFS, TPR, HRTEM, and EDS elemental mapping. The oxidation-reduction treatments were found to assist in sintering the metallic clusters to a larger size, and to promote mixing on at least the order of the nanoscale. The larger crystallites in closer proximity to the Ru promoter led to a more facile reduction of the cobalt crystallites. In addition, a catalyst exposed to two oxidation-reduction cycles resulted in slightly higher conversion, higher a-value product, slightly lower methane selectivity, and greater stability over a reduced freshly calcined catalyst.

  20. 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).