Loy Yang褐煤热解过程中HCN和NH3形成的主要影响因素

引　言热解是煤燃烧和气化的初始步骤 ,作为煤有机成分之一的N在煤热解过程中将随挥发分的释放而转化为NH3、HCN和少量的HNCO等气态NOx 前驱物、N2 以及焦油N和焦N1,2 ] ,这些NOx 前驱物及焦N在后续的燃烧、气化过程中将转化为NOx/N2 O或者N2 3,4 ] .煤燃烧过程中释放的NOx/N

SOME FACTORS INFLUENCING FORMATION OF HCN AND NH3 DURING PYROLYSIS OF BROWN COAL

A Victorian (Loy Yang) brown coal was pyrolysed in a novel fluidised-bed/fixed-bed reactor under a wide range of experimental conditions. The experimental data indicated that HCN originated mainly from the thermally less stable N-containing structures in the coal. Significant amounts of NH₃ could be formed after the feed of coal was stopped as a result of the slow hydrogenation of the thermally more stable N-containing structure by H radicals. In addition to temperature, gas flow rate and coal feed rate could significantly affect the formation of HCN although the yield of NH₃ remained almost unchanged, indicating that HCN was not significantly converted to NH₃. The effects of coal feed rate on HCN yields were different at the temperature of 973 K and 1073 K.