Pyrolysis of lignin in coal-tar pitch

Abstract

The pyrolysis of hydrolytic lignin in coal-tar pitch over a temperature range of 320–380°C was studied in a batch reactor at atmospheric pressure. As a result of reactions with pitch, lignin underwent dissolution and destruction with the formation of compounds that remained in the reactor or were released from the reactor as liquid and gaseous products. The liquid products of the pyrolysis of lignin consist of organic and aqueous phases. The organic products of the pyrolysis of lignin in pitch predominantly contain guaiacol and its derivatives. The chemical interaction of coal-tar pitch with lignin leads to changes in the characteristics of pitch, an increase in the softening point, an increase in the concentrations of compounds insoluble in toluene and quinoline, and an increased yield of the coke residue.