Koppers-Totzek Process Gasification Plants

The Koppers-Totzek process was first commercialized in 1952 and, by 1984, was used in 19 plants in 17 different countries [27]. The process uses powdered coal at atmospheric pressures in a parallel flow of 02 and H20 at temperatures of 1400-2000°C. The high process temperatures eliminate the formation of hydrocarbons and produce a gas containing 85—90% syngas (CO and H2). A process schematic is shown in Figure 2.26 [37]. Recent process developments include the Pressurized Entrained Flow Gasification (PRENFLO) with operating pressures being increased to 40 bars. 

The Prenflo Process (Pressurized Entrained Flow Gasification), an advanced 25-30 bar version of the atmospheric Koppers-Totzek process, is currendy on its way to becoming operative. A demonstration plant designed for a coal throughput of 2.0 t/h has been operating since 1986. Apart from the fact that the raw gas provided by this process is obtained at an elevated pressure, its improved coal conversion rate promises a markedly better cold gas efficiency. Initially, the new process variant was launched in cooperation between Koppers and SHELL, but it is now pursued by the former alone while SHELL went its own way. 

Coal Gasification Plant Conceptual Design-Koppers-Totzek Process. Alhambra, California CF Braun under contract to Tennessee Valley Authority, October 1980. 

While numerous processes have been proposed and are at the pilot plant stage, the two commercially available coal gasification processes for the production of synthesis gas or pipeline quality gas are the Lurgi process and the Koppers-Totzek process. 

Koppers-Totzek A coal gasification process using an entrained bed. The coal is finely ground and injected in a jet of steam and oxygen into a circular vessel maintained at 1,500°C. Reaction is complete within one second. The ash is removed as a molten slag. The process was invented by F. Totzek at Heinrich Koppers, Essen, and further developed by Koppers Company in Louisiana, MO, under contract with the U.S. Bureau of Mines. The first commercial operation was at Oulu, Finland, in 1952 by 1979, 53 units had been built. Most of the plants are operated to produce a hydrogen-rich gas for use in ammonia synthesis. Developed by Lurgi. See also PRENFLO. 

So far only the Koppers - Totzek, Texaco and Lurgi gasifiers, and probably the Winkler process in some smaller installations, have been used in ammonia plants, but the successful demonstration of the Shell process in other applications make it a potential candidate for ammonia production, too. Additional processes in different stages of technical development are the HTW and the Dow process. Information on the status and the development in the gasification of coal can be obtained from [541], [545], [548] -[554],... 

Entrained coal gasifiers are typified by the Koppers-Totzek (KT) and Texaco processes. Most of the present coal-based ammonia plants (except in China) use the KT process. The process is essentially a partial oxidation process as are most coal gasification processes. At least two KT ammonia plants have been built to use either coal or heavy oil although only one (in Finland) is known to have used both feedstocks [48]. However, any entrained gasification units presumably could be readily adapted to heavy oil or lighter hydrocarbons including natural gas. 

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