Coal Hydrogenation Processes

In 1931 the four major companies interested in the hydrogenation process— 

Faiben, Standard Oil (New Jersey), Royal Dutch Shell, and ICl—became associated in the International Hydrogenation Patents Company to pool their patent rights and exchange technical informatioa  

These activities made significant contributions to both sides during World War II for the production of aviation gasoline. Subsequently rapid developments led to many other chemical and refinery processes based on catalysts. These are listed in Table 2.13. 

It was found during pilot plant testing that maximum yields of Uquid hydrocarbons could only be obtained if the coal, or later tar and creosote, was partly 

TABLE 2.13. Processes Developed from Coal Hydrogenation 

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The results reported here have important implications for coal hydrogenation processes. 

Expanding the coal hydrogenation process to a small factory-size operation at this time forced Bergius to seek a larger and more economical source of hydrogen gas than he had obtained from the iron-superheated water reaction. (15)... 

Takeya, G. Studies of the Structure of Coal and Coal Hydrogenation Process. Pure and Appl. Chem., 1978,. 50, 1099-1115. 

This two-stage process for the hydrogenation of tar proved useful also for the hydrogenation of coal and petroleum oils in subsequent operations these two phases of the coal-hydrogenation process developed separately, requiring different catalysts and equipment. 

Bubble columns, in which the liquid is the continuous phase, are used for slow reactions. Drawbacks with respect to packed columns are the higher pressure drop and the important degree of axial and radial mixing of both the gas and the liquid, which may be detrimental for the selectivity in complex reactions. On the other hand they may be used when the fluids carry solid impurities that would plug packed columns. In fact, many bubble column processes involve a finely divided solid catalyst that is kept in suspension, like the Rheinpreussen Fischer-Tropsch synthesis, described by Kolbel [1], or the former I. G. Farben coal hydrogen process, or vegetable oil hardening processes. Several oxidations are carried out in bubble columns the production of acetaldehyde from ethylene, of acetic acid from C4 fractions, of vinylchloride from ethylene by oxychlorina-tion, and of cyclohexanone from cyclohexanol. 

Despite its smaller size and lower production, the 9 F-T plants contributed 455,000-576,000 metric tons of coal-derived oil per year during the war years 12-15 percent of Germany s total liquid fuel requirement. The historical analysis that follows examines the T-T s invention and industrial development during several decades of German social, political, and economic unrest and complements the historical literature on Germany s coal hydrogenation process. The... 

Although yields obtained with this method are lower than when hydrogen gas is used, the lower pressure required makes this process suitable for coal liquefaction. Alternatively, it may be used as the first stage in coal hydrogenation processes. 

Thermal efficiency of the process is much lower than coal hydrogenation processes. 

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