Hydrogasification of Liquid Ammonia-treated Coals (II)

The liquid ammonia-treated coal shows a large reactivity in hydrogasification, when catalyzed by nickel. In this paper, the reactivity was compared for six Japanese coals, the carbon content of which ranged from 75% to 87% daf.The coal specimens were heated in a thermobalance in a stream of hydrogen, ca. 100cm3 (STP) /min, up to 1, 000°C, and the rate of methane formation was measured by a gas chromatograph.The rates of methane formation of the coals treated with liquid ammonia at 120°C and then impregnated with nickel catalyst (TC coal) were compared with those of the untreated original coal (UN) or of the nickel-impregnated coal without the liquid ammonia treatment (UC).The UC and TC coals presented large peaks of methane formation at ca. 350°C and above 800°C, in addition to peaks between 400°C and 750°C, which were common to every specimen. The rates of methane fromation of TC coals at the high temperature region were significantly large compared with those of UC coals, which suggests that the effect of the liquid ammonia treatment is to raise the reactivity of catalytic hydrogasification. This reactivity became higher as the carbon content of the original coal increased, so far as the coals examined here were concerned. The effect of caking property was also discussed.