Japanese bituminous coals, treated with liquid ammonia and impregnated with nickel, were gasified with hydrogen at ambient pressure. The rates of gasification of the treated coals were larger than those of untreated ones by 2 to 8 times at 1273 K. A repeated treatment with liquid ammonia enhanced the reactivity further, but a third (or more) treatment was not so effective. Pretreatment with ethylene diamine, butylamine, pyridine, or sulphur dioxide caused a similar promotion of the gasification, while that with benzene, dimethyl formamide, or propane was less effective.
Liquidammonia-treated coals seem to reduce or lose their agglomerating ability and thus to maintain higher gasification rates.
Catalysts at the coal gasification stage can be useful either to increase the reaction rate or to improve the product selectivity', though most of the developing processes use thermal reaction at this stage. One of the major problems associated with the utilization of catalyst is to make an effective contact between coal and catalyst. We have shown in the preceding report that liquid ammonia can extract a few per cent of tarry materials from a bituminous coal at 393 K and that the treated coal was gasified with hydrogen at a rate higher than that of the untreated coal when impregnated with nickel'. In the present report, the effect of the pretreatment on the gasification reactivity is examined in more detail, including a comparison with other nonaqueous solvents.