Changes in vitroplast derived from a high-volatile bituminous coal during tetralin treatment

At an early stage in the hydrogenation of coal using tetralin, a thermoplastic material called vitroplast is formed from vitrinite as one of its primary products. Subsequent changes in the vitroplast depend on the physical and chemical conditions of the coal/solvent mixture: under favourable conditions vitroplast is converted to liquid and gas; otherwise it forms mesophase. Secondary vitroplast is formed, under certain conditions, from previously liquefied material by precipitation or thermal polymerization. In an autoclave, and probably also in a continuous hydrogenation reactor, interconversions between primary and secondary vitroplast, liquid and gaseous products and mesophase take place simultaneously, the overall reaction being the sum of the various reactions.