Cobalt catalysts synthesis

The water gas shift reaction is fast on alkalized iron catalysts, but merely proceeds on cobalt catalysts. Synthesis gases from high temperature coal- or heavy oil gasification with high CO-content can directly be used for FT-... 

Goal Upgrading via Fischer-Tropsch. The synthesis of methane by the catalytic reduction of carbon monoxide and hydrogen over nickel and cobalt catalysts at atmospheric pressure was reported in 1902 (11). 

During World War II, nine commercial plants were operated in Germany, five using the normal pressure synthesis, two the medium pressure process, and two having converters of both types. The largest plants had capacities of ca 400 mr / d (2500 bbl/d) of Hquid products. Cobalt catalysts were used exclusively. 

Conventional Transportation Fuels. Synthesis gas produced from coal gasification or from natural gas by partial oxidation or steam reforming can be converted into a variety of transportation fuels, such as gasoline, aviation turbine fuel (see Aviation and other gas turbine fuels), and diesel fuel. A widely known process used for this appHcation is the Eischer-Tropsch process which converts synthesis gas into largely aHphatic hydrocarbons over an iron or cobalt catalyst. The process was operated successfully in Germany during World War II and is being used commercially at the Sasol plants in South Africa. 

Medium Pressure Synthesis. Pressures of 500—2000 kPa (5—20 atm) were typical for the medium pressure Fischer-Tropsch process. Cobalt catalysts similar to those used for the normal pressure synthesis were typically used at temperatures ranging from 170 to 200°C ia tubular "heat exchanger" type reactors. 

A Belgian patent (178) claims improved ethanol selectivity of over 62%, starting with methanol and synthesis gas and using a cobalt catalyst with a hahde promoter and a tertiary phosphine. At 195°C, and initial carbon monoxide pressure of 7.1 MPa (70 atm) and hydrogen pressure of 7.1 MPa, methanol conversions of 30% were indicated, but the selectivity for acetic acid and methyl acetate, usehil by-products from this reaction, was only 7%. Ruthenium and osmium catalysts (179,180) have also been employed for this reaction. The addition of a bicycHc trialkyl phosphine is claimed to increase methanol conversion from 24% to 89% (181). 

Hydroformylation. In hydroformylation, the 0x0 reaction, ethylene reacts with synthesis gas (CO + H2) over a cobalt catalyst at 60—200°C... 

Alkyne-nitrile cyclotrimerization is a powerful synthetic methodology for the synthesis of complex heterocyclic aromatic molecules.118 Recently, Fatland et al. developed an aqueous alkyne-nitrile cyclotrimerization of one nitrile with two alkynes for the synthesis of highly functionalized pyridines by a water-soluble cobalt catalyst (Eq. 4.62). The reaction was chemospecific and several different functional groups such as unprotected alcohols, ketones, and amines were compatible with the reaction.119 In addition, photocatalyzed [2+2+2] alkyne or alkyne-nitrile cyclotrimerization in water120 and cyclotrimerization in supercritical H2O110121 have been reported in recent years. 

Lin, J. J. (Texaco Development Corp.) Process for synthesis of amidoacids using a cobalt catalyst and a bidentate phosphine ligand Eur. Pat. Appl. 263,624 1988. Chem. Abstr. 1989, 110, 154881. 

Jacobs G., Das T.K., Zhang Y., Li J., Racoillet G., Davis B.H. 2002. Fischer-Tropsch synthesis Support, loading and promoter effects on the reducibility of cobalt catalysts. Appl. Catal. A Gen. 233 263-81. 

Ellis PR. and Bishop P.T. 2006. Supported cobalt catalysts for the Fischer-Tropsch synthesis. International Patent Application WO2006/136863. 

Bezemer, G. L., Radstake, P. B., Falke, U., Oosterbeek, H., Kuipers, H. P. C. E., van Dillen, A., and de Jong, K. P. 2006. Investigation of promoter effects of manganese oxide on carbon nanofiber-supported cobalt catalysts for Fischer-Tropsch synthesis. Journal of Catalysis 237 152-61. 

Tavasoli, A., Abbaslou, R. M. M., Trepanier, M., and Dalai, A. K. 2008. Fischer-Tropsch synthesis over cobalt catalyst supported on carbon nanotubes in a slurry reactor. Applied Catalysis A General 345 134-42. 

Yu, Z., Borg, 0., Chen, D., Enger, B. C., Frpseth, V., Rytter, E., Wigum, H., and Holmen, A. 2006. Carbon nanofiber supported cobalt catalysts for Fischer-Tropsch synthesis with high activity and selectivity. Catalysis Letters 109 43 -7. 

Yates, I. C., and Satterfield, C. N. 1991. Intrinsic kinetics of the Fischer-Tropsch synthesis on a cobalt catalyst. Energy Fuels 5 168-73. 

Huang, X. W., Elbashir N. O., and Roberts, C. B. 2004. Supercritical solvent effects on hydrocarbon product distributions from Fischer-Tropsch synthesis over an alumina-supported cobalt catalyst. Industrial Engineering Chemistry Research 43 6369-81. 

Effect of a Novel Nitric Oxide Calcination on the Catalytic Behavior of Silica-Supported Cobalt Catalysts during Fischer-Tropsch Synthesis, and Impact on Performance Parameters... 

Vada, S., Hoff, A., Adnane, E., Schanke, D., and Holmen, A. 1995. Fischer-Tropsch synthesis on supported cobalt catalysts promoted by platinum and rhenium. Topics Catal. 2 155-62. 

Ma, W.P., Jacobs, G., Sparks, D.E., Spicer, R.L., Graham, U.M., and Davis, B. H. 2008. Comparison of the kinetics of the Fischer-Tropsch synthesis reaction between structured alumina supported cobalt catalysts with different pore size. Prepr. Am. Chem. Soc. Div. Petro. Chem. 53 99-102. (see Chapter 8 of this book.)... 

Although the FTS is considered a carbon in-sensitive reaction,30 deactivation of the cobalt active phase by carbon deposition during FTS has been widely postulated.31-38 This mechanism, however, is hard to prove during realistic synthesis conditions due to the presence of heavy hydrocarbon wax product and the potential spillover and buildup of inert carbon on the catalyst support. Also, studies on supported cobalt catalysts have been conducted that suggest deactivation by pore plugging of narrow catalyst pores by the heavy (> 40) wax product.39,40 Very often, regeneration treatments that remove these carbonaceous phases from the catalyst result in reactivation of the catalyst.32 Many of the companies with experience in cobalt-based FTS research report that these catalysts are negatively influenced by carbon (Table 4.1). 

Additionally, the following factors are believed to have an increase in the amount of carbon deposited on cobalt catalysts higher reaction temperature,39-63 lower H2/CO ratio,63 higher CO partial pressures,59 and cleaner (sulfur-free) synthesis gas.33-64... 

Kiss, G., KJiewer, C. E., DeMartin, G. J., Culross, C. C., and Baumgartner, J. E. 2003. Hydrothermal deactivation of silica-supported cobalt catalysts in Fischer-Tropsch synthesis. J. Catal. 217 127-40. 

Gruver, V., Young, R., Engman, J., and Robota, H. J. 2005. The role of accumulated carbon in deactivating cobalt catalysts during FT synthesis in a slurry-bubble-column reactor. Prepr. Pap.-Am. Chem. Soc. Div. Pet. Chem. 50 164—66. 

Beitel, G. A., de Groot, C. P. M., Oosterbeek, H., and Wilson, J. H. 1997. A combined in-situ PM-RAIRS and kinetic study of single-crystal cobalt catalysts under synthesis gas at pressures up to 300 mbar. J. Phys. Chem. B 101 4035-43. 

Iglesia, E., Soled, S. L., Baumgartner, J. E., and Reyes, S. C. 1995. Synthesis and catalytic properties of eggshell cobalt catalysts for the Fischer-Tropsch synthesis. J. Catal. 153 108-22. 

Kraum, M., and Baems, M. 1999. Fischer-Tropsch synthesis The influence of various cobalt compounds applied in the preparation of supported cobalt catalysts on their performance. Appl. Catal. A Gen. 186 189-200. 

Ohtsuka, Y., Arai, T., Takasaki, S., and Tsubouchi, N. 2003. Fischer-Tropsch synthesis with cobalt catalysts supported on mesoporous silica for efficient production of diesel fuel fraction. Energy Fuels 17 804-9. 

Tsubaki, N., Sun, S., and Fujimoto, K. 2001. Different functions of the novel metals added to cobalt catalysts for Fischer-Tropsch synthesis. J. Catal. 199 236 -6. 

Zhang, Y., Shinoda, M., and Tsubaki, N. 2004. Development of bimodal cobalt catalysts for Fischer-Tropsch synthesis. Catal. Today 93 55-63. 

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