Hydrogen production from coal involves gasification of coal with steam and oxygen; and physical-chemical cleaning of the raw gas produced. The aim in coal gasification is the conversion of coal to light gases in the presence of reactive gaseous atmosphere while increasing H/C ratio. H_2 and CO are the main constituents obtained in the gasifier; and the composition of the raw gas is determined by the properties of the coal and of the oxidizing agent, by the type of the process applied and by the operational conditions. The Winkler, the Lurgi and the Koppers Totzek processes are the precesses which already have some commercial applications. Among them, the processes with high CO + H_2 output and with low CH_4 production are especially advantageous for the production of Hydrogen. Comparisons of industrial Koppers and Winkler systems consuming the same coal as raw material indicates that the Koppers process is more convenient for that purpose.
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