Effect of temperature on chemical composition of oil from direct liquefaction of Mukah Balingian coal in tetralin-glycerol mixed solvent system

Coal-derived liquids or oils from coal liquefaction are an attractive commodity as they could be a source of transportation fuels and feedstocks for the chemical industry. Analysis of the chemical composition is essential to determine the suitable usage of the liquids from the coal liquefaction process. The common instruments used for this purpose are GC-MS, FT-IR and 1H NMR. In this study, the chemical composition of oils produced from direct liquefaction of Mukah Balingian coal in a tetralin-glycerol solvent system was carried out using GC-MS. This work aims to investigate the effect of liquefaction temperature on the qualitative and quantitative aspects of the oils produced. Although all of the oils contain similar trends of chemical composition, the per cent areas of these compounds showed a notable change due to different temperatures used during the liquefaction process. The liquefaction condition is of low pressure and high temperature, so the aromatisation reaction is favoured. As a result, the aromatic components in oils were increased as the temperature was raised due to the predominate reaction of dehydrogenation, thus producing more aromatics of hydrogen-depleted compounds.