Thermal Dissolution of Shenfu Sub-Bituminous Coal Promoted by Lignin

Abstract

Objective: Thermal Dissolution (TD) and Co-thermal Dissolution (CTD) of Shenfu (SF) coal and lignin were studied. The effect of temperature on the TD and CTD of SF coal and lignin was discussed. Method: The synergistic effect of SF coal and lignin in CTD was probed with the characterization of thermal dissolution soluble fraction by elementary analysis, FTIR and TG determinations. Result: The results suggested that TD activity of lignin was higher than that of SF coal. Both SF coal and lignin gave their maximal thermal dissolution yield (TDY) of 57.6 and 82.5%, respectively at 360oC. In CTD of SF coal and lignin process, the experimental values (expressed by EXP) of TDY and Thermal Dissolution Soluble Yield (TSY) were both higher than the corresponding calculated weighted mean values (expressed by CAL) of TDY and TSY obtained from the individual TD of SF coal and lignin, suggesting that there existed a synergistic effect in the CTD of SF coal and lignin. Both TDY and TSY in CTD were enhanced to maximal values at 360oC with (EXP-CAL) values of 3.4 and 7.5%, respectively. Conclusion: There were interactions between SF coal and lignin in the CTD process. The pyrolysis of lignin at low temperature may form some intermediates such as phenoxy radicals, and these intermediates can further cause depolymerization of coal, thus promoting the TD of coal.