Fischer-Tropsch synthesi

A number of chemical products are derived from Sasol s synthetic fuel operations based on the Fischer-Tropsch synthesis including paraffin waxes from the Arge process and several polar and nonpolar hydrocarbon mixtures from the Synthol process. Products suitable for use as hot melt adhesives, PVC lubricants, cormgated cardboard coating emulsions, and poHshes have been developed from Arge waxes. Wax blends containing medium and hard wax fractions are useful for making candles, and over 20,000 t/yr of wax are sold for this appHcation. 

The second reaction is called the Fischer-Tropsch synthesis of hydrocarbons. Depending on the conditions and catalysts, a wide range of hydrocarbons from very light materials up to heavy waxes can be produced. Catalysts for the Fischer-Tropsch reaction iaclude iron, cobalt, nickel, and mthenium. Reaction temperatures range from about 150 to 350°C reaction pressures range from 0.1 to tens of MPa (1 to several hundred atm) (77). The Fischer-Tropsch process was developed iadustriaHy under the designation of the Synthol process by the M. W. Kellogg Co. from 1940 to 1960 (83). 

Heat Release and Reactor Stability. Highly exothermic reactions, such as with phthaHc anhydride manufacture or Fischer-Tropsch synthesis, compounded with the low thermal conductivity of catalyst peUets, make fixed-bed reactors vulnerable to temperature excursions and mnaways. The larger fixed-bed reactors are more difficult to control and thus may limit the reactions to jacketed bundles of tubes with diameters under - 5 cm. The concerns may even be sufficiently large to favor the more complex but back-mixed slurry reactors. 

Fischer-Tropsch Waxes. Polymethylene wax [8002-74-2] production is based on the Fischer-Tropsch synthesis, which is basicaHy the polymerisation of carbon monoxide under high pressure and over special catalysts to produce hydrocarbons (see Fuels, synthetic-liquid fuels). 

The first demonstration of catalytic conversion of synthesis gas to hydrocarbons was accompHshed ia 1902 usiag a nickel catalyst (42). The fundamental research and process development on the catalytic reduction of carbon monoxide was carried out by Fischer, Tropsch, and Pichler (43). Whereas the chemistry of the Fischer-Tropsch synthesis is complex, generalized stoichiometric relationships are often used to represent the fundamental aspects ... 

Fig. 11. Optimum pressure/temperature ranges for Fischer-Tropsch synthesis processes showiag the various catalysts ia parentheses. To convert MPa to...

General References Dry, The Fischer-Tropsch Synthesis, Catalysis Sci-... 

Fischer-Tropsch Synthesis The best-known technology for producing hydrocarbons from synthesis gas is the Fischer-Tropsch synthesis. This technology was first demonstrated in Germany in 1902 by Sabatier and Senderens when they hydrogenated carbon monoxide (CO) to methane, using a nickel catalyst. In 1926 Fischer and Tropsch were awarded a patent for the discovery of a catalytic technique to convert synthesis gas to liquid hydrocarbons similar to petroleum. 

Other reactions may also occur during the Fischer-Tropsch synthesis, depending on the catalyst employed and the conditions used Water-gas shift ... 

The indirect liquefaction basehne design is for a plant of similar size. Unhke the direct hquefaction basehne, the design focuses on producing refined transportation fuels by use of Sheh gasification technology. Table 27-17 shows that the crude oil equivalent price is approximately 216/m ( 34/bbl). Additional technological advances in the production of synthesis gas, the Fischer-Tropsch synthesis, and product refining have the potential to reduce the cost to 171/m ( 27/bbl) (1993 US dollars), as shown in the second column of Table 27-17. 

As an example of the chemical signihcance of the process technology, the products of die Fischer-Tropsch synthesis, in which a signihcant amount of gas phase polymerization occurs vary markedly from hxed bed operation to the fluidized bed. The hxed bed product contains a higher proportion of straight chain hydrocarbons, and the huidized bed produces a larger proportion of branched chain compounds. 

J.R. Anderson and M. Boudait (eds), Catalysis, Science and Technology, Several volumes. Springer Verlag, Berlin TP156 C35 C375 Volume 1 M.E. Diy, The Fischer-Tropsch synthesis, pp. 160-255. 

Hot (230-240°F) potassium carbonate treating was patented in Germany in 1904 and perfected into modem commercial requirements by the U.S. Bureau of Mines. The U.S. Bureau of Mines was working on Fischer-Tropsch synthesis gas at the time. Potassium carbonate treating requires high partial pressures of CO2. It therefore cannot successfully treat gas containing only H2S. ... 

Masters, Adv. Organometallic Chem. 17, 61-103 (1979). R. B. Anderson, The Fischer-Tropsch Synthesis, Academic Press, London, 1984, 320 pp. 

Diy, M. E. (1990). Fischer-Tropsch Synthesis over Iron Catalysts, Spring 1990 A.I.Ch.E. Meeting, Orlando, Florida. March 18-22, 1990. 

During the late seventies and early eighties, when oil prices rose after the 1973 war, extensive research was done to change coal to liquid hydrocarbons. However, coal-derived hydrocarbons were more expensive than crude oils. Another way to use coal is through gasification to a fuel gas mixture of CO and H2 (medium Btu gas). This gas mixture could be used as a fuel or as a synthesis gas mixture for the production of fuels and chemicals via a Fischer Tropsch synthesis route. This process is... 

Synthesis gas consists of a nonhydrocarhon mixture (H2,CO) ohtain-ahle from more than one source. It is included in this chapter and is further noted in Chapter 5 in relation to methane as a major feedstock for this mixture. This chapter discusses the use of synthesis gas obtained from coal gasification and from different petroleum sources for producing gaseous as well as liquid hydrocarbons (Fischer Tropsch synthesis). 

Hydrocarbons from Synthesis Gas (Fischer Tropsch Synthesis, FTS)... 

Fischer Tropsch synthesis is catalyzed by a variety of transition metals such as iron, nickel, and cobalt. Iron is the preferred catalyst due to its higher activity and lower cost. Nickel produces large amounts of methane, while cobalt has a lower reaction rate and lower selectivity than iron. By comparing cobalt and iron catalysts, it was found that cobalt promotes more middle-distillate products. In FTS, cobalt produces... 

Dry, M. E., The Fischer Tropsch Synthesis, in Catalysis Science and Technology, edited hy J. R. Anderson and M. Boudart, Springer Verlag, 1981. 

Rober, M. Fischer-Tropsch Synthesis in Catalysis in Cj Chemistry, edited by W. Keim, D. Reidel Publishing Company, Dordrecht, The Netherlands, 1983, pp. 41-87. 

Many chemicals are produced from synthesis gas. This is a consequence of the high reactivity associated with hydrogen and carhon monoxide gases, the two constituents of synthesis gas. The reactivity of this mixture was demonstrated during World War II, when it was used to produce alternative hydrocarbon fuels using Fischer Tropsch technology. The synthesis gas mixture was produced then hy gasifying coal. Fischer Tropsch synthesis of hydrocarbons is discussed in Chapter 4. 

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