Coal char gasification using alkali metal catalysts

In order to simplify the experimental procedure and the interpretation of results, coal char rather than coal was used to study steam gasification of a Wyoming sub-bituminous coal with alkali metal salts as catalysts. Coal/catalyst contacting was accomplished by aqueous impregnation of the coal with catalyst. Gasification rates and gas production rates were measured as a function of catalyst type, catalyst loading, and reactor temperature. Steam partial pressure was maintained constant at one half of an atmosphere. Temperature was varied from 600 to 900/sup 0/C. Initial catalyst screening studies indicated that K/sub 2/CO/sub 3/ and KOH gave identical results and that both were superior to alkali chlorides in enhancing gasification rates. K/sub 2/CO/sub 3/ was then used exclusively in all subsequent studies. The following major conclusions can be drawn: Enhancement in the gasification rate results from increased catalyst loading and decreased thermal aging; activation energies decrease with increasing catalyst loading and have values of 39.1, 44.8, and 49.1 Kcal/mole for 10, 5, and 0 percent loadings of potassium, respectively; increasing temperature causes carbon monoxide to be formed in preference to carbon dioxide and hydrogen, and enhances the rate of methane production; and increasing catalyst loading causes carbon monoxide to be formed in preference to carbon dioxide and hydrogen, but diminishes the rate of methane production.