Pyrolysis–Gas Chromatography of Lakhra Coal: Effect of Temperature and Inorganic Matter on the Product Distribution

The objective of this article was to study the effect of pyrolysis temperature and mineral matter on the distribution of the product of C1-C6 hydrocarbons. Pakistani lignite named as Lakhra 6B was used to study the effect of inorganic substances on the reactivity of coal. The experiments were performed using pyrolysis gas chromatography to investigate the activity of virgin coal, HCl acid-washed coal and acid-washed coal with (Ca(C2H3O2)2, Mg(C2H3O2)2, NaC2H3O2, KC2H3O2), added respectively. The products obtained were monitored by a gas chromatograph. The main products identified were methane, ethane, ethylene, propane, 1-butene, n-butane, 1-pentene, n-pentane and benzene. The results showed that coal conversion to methane increased with an increase in temperature and the amount of this hydrocarbon was high among all the hydrocarbons formed. It was observed that the addition of metal ions affected the yields of the products in a selective manner. The yield of benzene was observed to be high in the case of calcium and magnesium form coals. The other cations form coals produced a smaller quantity of benzene in the temperature range studied. From the results, it can be concluded that metal ions played a selective role in controlling the yield of C1-C6 hydrocarbons from coal pyrolysis in general and benzene yield in particular.