Gaseous products of the thermolysis of brown coal impregnated with potassium hydroxide

Abstract

The yields of gaseous products (H2, CO, CO2, and CnH2n + 2 at n = 1−4) from brown coal and brown coal-KOH compounds were determined under conditions of nonisothermal heating (4°C/min) to 800°C followed by an isothermal exposure (1 h, 800°C). It was found that, in the presence of the alkali, the yields of H2, CO, C2H6, and C3H8 increased; the yields of CO2 and CH4 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 dealkylation reactions of arene and alkane structural fragments, in which KOH molecules served as H-atom donors in the formation of H2 and alkanes.