Gasoline, synthesis

The use of a fluidized-bed reactor is possible only when the reactants are essentiaUy in the gaseous phase. Eluidized-beds are not suitable for middle distiUate synthesis, where a heavy wax is formed. Eor gasoline synthesis processes like the MobU MTG process and the Synthol process, such reactors are especiaUy suitable when frequent or continuous regeneration of the catalyst is required. Slurry reactors and ebuUiating-bed reactors comprising a three-phase system with very fine catalyst are, in principle, suitable for middle distiUate and wax synthesis, but have not been appHed on a commercial scale. 

Director Coal-Research Institute at Muehlheim (1914—1943) Invention of gasoline synthesis (at normal pressure) together with Hans Tropsch in 1925... 

TIGAS [Topsoe integrated gasoline synthesis] A multi-stage process for converting natural gas to gasoline. Developed by Haldor Topsoe and piloted in Houston from 1984 to 1987. Not commercialized, but used in 1995 as the basis for a process for making dimethyl ether for use as a diesel fuel. 

Gasoline synthesis, by catalytic conversion of carbon monoxide and hydrogen, 4 271 Gas-phase... 

A brief outline of the products expected in a demonstration plant and in future commercial plants is shown in Figure 2. In future commercial plants, for example, ethane and propane could be utilized as chemical intermediates and naphtha as a source of chemicals or for production of high-octane unleaded gasoline. Synthesis gas produced in excess of the requirements for hydrogen could be utilized as a source of chemicals as well as a fuel. The fuel oil could be selectively fractionated to produce a middle distillate for use as turbine fuel, light industrial boiler fuel or refinery feedstocks, while the heavy distillate could serve as a fuel oil for large utility boilers. 

Inui, T. and Kim, J. B. High quality gasoline synthesis by selective oligomerization of light olefins and successive hydrogenation. Stud. Surf. Sci. Catal., 1996, 100, 489 498. 

Fig. 1. Luther R. Hill s sketch of June 14, 1946, proposing a circulating-fluid-bed reactor for gasoline synthesis. The arrangement is a poor idea (see Section III for description of troubles that Sasol encountered in operating the heat exchangers depicted in Fig. 4, which also required gas and powder to flow upward via parallel paths).

Fig. 2. First M. W. Kellogg Company fast-bed pilot plant for gasoline synthesis.

Fig. 3. Second M. W. Kellogg Company fast-bed pilot plant for gasoline synthesis. Initially, the two upper sections of the 4-inch fast bed were fitted with tubular heat exchangers—i.e., vertical tubes, with tube sheets above and below, and with the tubes surrounded by a cooling oil. Later, these exchangers were replaced by oil-jacketed sections of open 4-inch pipe. The dashed lines indicate other changes made after initial shakedown operations, having two effects lengthening the 2-inch standpipe, and causing catalyst to discharge well below filter elements mounted in the expanded section near the top of the hopper seen on the right.

Something should be said about sequelae to Kellogg s and Hydrocarbon Research s gasoline synthesis development efforts of the late 1940s. 

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. 

In the late 1980s and early 1990s, Soekor erected yet another gasoline synthesis plant using Sasol fast-bed synthesis technology at Mossel Bay, South Africa. The plant was based upon offshore natural gas. 

Figure 3 Results of gasoline synthesis from carbon oxides via methanol...

HIGH QUALITY GASOLINE SYNTHESIS BY SELECTIVE OLIGOMERIZATION OF LIGHT OLEFINS AND SUCCESSIVE HYDROGENATION... 

TOPS0E INTEGRATED GASOLINE SYNTHESIS - THE TIGAS PROCESS J. TOPP-J0RGENSEN... 

The gasoline synthesis involves three sequential steps (Fig. 2). Thus, when a process is to be designed, two different approaches can be used. Each step in the synthesis can be treated either as a rather independent plant, or process integration can be attempted. 

The aim of the process development work on the integrated gasoline synthesis has been to arrive at a process scheme in which all three steps of the conversion of natural gas to gasoline are conducted at the same pressure level. This means that operating conditions and catalysts should be modified so that the low pressure processes can operate at relatively high pressure, and efforts should be made to reduce the necessary operating pressure of the MeOH synthesis. 

The exploratory work on the integrated gasoline synthesis was commenced in the late seventies in bench-scale reactors. After successful results process studies and ageing tests were carried out in a 15 kg gasoline per day pilot plant. 

The simplest way of integrating MeOH synthesis with gasoline synthesis is to operate both processes at the pressure of a conventional MeOH plant, i.e. 

However, in the integrated gasoline synthesis there is no reason to restrict the formation of oxygenates to MeOH, as the HZSM-5 catalyst employed in the third step of the integrated gasoline synthesis can convert not only MeOH but a wide range of other oxygenates to hydrocarbons as well (ref. 5). 

If the integrated process is operated with a cycle length of approx. 6 months, the plant can be shut down for regeneration every 6 months and the existing equipment in the loop used for regeneration. In this way multiple reactors and a separate regeneration system for the gasoline synthesis can be avoided, and the investment costs for the plant further reduced. 

The purpose of the process development work on the integrated gasoline synthesis was to modify the three process steps, synthesis gas production, oxygenate synthesis and the MTG process, in order to be able to operate all steps at the same pressure and the last two steps in one single synthesis loop. 

Process flexibility and simplicity are main features of the Integrated Gasoline Synthesis. Yield and quality, cycle length etc. can be adjusted to ensure a desired balance between capital investment and operating costs. Synthesis gas compression can be avoided. This means low investment. Further, the exclusion of the synthesis gas compressor means higher reliability. 

GASOLINE SYNTHESIS PROM CARBON MONOXIDE AND HYDROGEN 273... 

GASOLINE SYNTHESIS FROM CARBON MONOXIDE AND HYDROGEN 275... 

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