Structure parameter correlations on alkali-alcohol treated lignite

The solubility of the Tuncbilek Lignite is increased up to 100% after KOH-Benzhydrol treatment. Meanwhile its oxygen, sulphur and ash contents are decreased considerably. It has been shown that the solubility, H/C and S/C ratios, as well as the sulphur content of the coal are well correlated with the hydrogen transferred from benzhydrol, whereas the oxygen content does not. The oxygen content correlate with the ash content. A reductive elimination mechanism is suggested for the removal of the hetero-atoms, which also causes the degradation and the increase of the solubility of the coal.