Gaseous Products of the Thermolysis of Brown Coal Impregnated with Potassium Hydroxide

摘要

The yields of gaseous products (H_2, CO, CO_2, and C_nH_(2n+2) at n = 1-4) from brown coal and brown coal-KOH compounds were determined under conditions of nonisothermal heating (4℃/min) to 800℃ followed by an isothermal exposure (1 h, 800℃). It was found that, in the presence of the alkali, the yields of H_2, CO, C_2H_6, and C_3H_8 increased; the yields of CO_2 and CH_4 decreased; and the formation of isobutane was completely suppressed. Changes in the gas compositions were explained by the alkali degradation of C-C bonds in the organic matter of coal and by the thermally initiated dehydrogenation and dealky-lation reactions of arene and alkane structural fragments, in which KOH molecules served as H-atom donors in the formation of H_2 and alkanes.