Sasolburg plant

SASOL in South Africa developed its F-T coal-to-oil process after World War 11. Its Sasolburg plant began liquid fiiel production in 1955, a second plant at Segunda (SASOL Two) opened in 1980, and a third plant SASOL Three in 1982. By 2001 SASOL was providing 29 percent of South Africa s motor fuel requirements, both gasoline and diesel, as well as industrial chemicals. 

Previous studies in the LTFT pilot plant units had shown that when these units were operated in the slurry mode at the same operating condition with catalyst of the same composition as that used in the fixed-bed mode, the performances were similar (20). Since the 0.9-m FFB demonstration imit had served its purpose, it was altered into a slurry bed unit and tested in 1990. This unit performed as predicted. The Sasolburg 5.1-m commercial FFB unit was then converted to a slurry unit and came online in 1993. Its production rate was the same as that of the combined five original fixed-bed ARGE units. Two new commercial slurry bed reactors are to be constructed at the Sasolburg plant. 

In Sasolburg, South Africa, a commercial plant using the Fischer-Tropsch process was completed in 1950 and began producing a variety of Hquid fuels and chemicals. The faciUty has been expanded to produce a considerable portion of South Africa s energy requirements (15,16). 

Consequently, two semicommercial pilot plants have been operated for 1.5 years. One plant, designed and erected by Lurgi and South African Coal, Oil, and Gas Corp. (SASOL), Sasolburg, South Africa, was operated as a sidestream plant to a commercial Fischer-Tropsch synthesis plant. Synthesis gas is produced in a commercial coal pressure gasification plant which includes Rectisol gas purification and shift conversion so the overall process scheme for producing SNG from coal could be demonstrated successfully. The other plant, a joint effort of Lurgi and El Paso Natural Gas Corp., was operated at the same time at Petrochemie Schwechat, near Vienna, Austria. Since the starting material was synthesis gas produced from naphtha, different reaction conditions from those of the SASOL plant have also been operated successfully. 

The world s largest concentration of Lurgi gasifiers is in South Africa, where Sasol operates three major complexes. The Sasol plants (Sasol I, II, and III) located in Seconda and Sasolburg gasify approximately 30 million ton/year of bituminous coal to synthesis gas, which is converted to fuels and chemicals via the Fisher-Tropsch process. It was recently announced (International Coal... 

CTL [Coal To Liquids] A general name for processes that convert coal to liquid hydrocarbons, usually for use as fuels. Sasol was building a prototype reactor in Sasolburg, South Africa, in 2006. The first U.S. plant is scheduled to be built in Gilberton, PA, for completion in 2009. 

Early in 1951 (probably in late March), Kellogg won a contract to build a gasoline synthesis facility for Sasol employing synthesis gas from coal (Pay, 1980 Dry, 1981). For the plant at Sasolburg, South Africa, the synthesis section would be essentially Kellogg s 1948 design for Cities Service, with minor modifications. Figure 4 is a sketch of a Sasol fast-bed reactor. 

This was much finer than the catalyst that seems to have been used in pilot plant operations of 1948. Lobo, 1929-1955, does not appear to contain information permitting one to judge when or why Kellogg decided to use catalyst of a smaller size. The 1953 size analysis, apparently, is roughly in accord with catalyst sizes employed in the synthesis fast-bed reactors at Sasolburg. 

Fused and precipitated iron catalysts are used in the commercial Fischer-Tropsch plants in Sasolburg. These catalysts contain various promoters, such as copper, which facilitates reduction of the catalyst, KjO which enhances activity and oictm selectivity, and Si02 which increases the surface area of the catalyst (15]. Recent literature contains numerous reports aimed at improving catalyst activity and selectivity. 

Figure 3 - Original Process Scheme of the Sasol 1 Plant - Sasolburg, South Africa...

Figure 4 - Process Work-up for the first Sasol LIFT plant in Sasolburg (1957)...

The process flow diagram for the Sasol 2 plant in Secunda, South Africa is presented in Figure 5 (12). The original Synthol HTFT reactors installed at Secunda were an improved and scaled-up version of the ones used in Sasolburg. 

Sasol in South Africa kept on their research on FTS and the Sasol One plant was built in Sasolburg in 1955. In 1969, the Natref crude oil refinery was commissioned. In 1980 and 1982, Sasol Two and Sasol Three, respectively, began production in Secunda (Dyk et al., 2006). Major accomplishments of Sasol in the design of catalysts, reactors, and processes for FTS have been summarized in recently published monograph (Aasberg, 2004). 

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