Thermochemical properties of coal fractions of different density: A review

Abstract

Research is reviewed regarding the composition and thermochemical properties of coal fractions of different density. The properties discussed are the thermogravimetric parameters; the free-swelling index; the plastic-layer thickness; the dilatometric characteristics; the yield of fluid (mobile) components of the plastic mass. These properties are determined by the petrographic (maceral) composition of the fractions. With increase in density of the fractions, the liptinite and vitrinite content declines, while the inertinite content grows. Consequently, the chemical structure becomes less aliphatic and more aromatic, with corresponding deterioration in thermochemical properties of the fractions. The results show that fractionation of the coal prior to processing is potentially very effective.