Effect of Oxygen Compounds on Hydrotreating of Coal-Derived Liquid

摘要

Coal derived liquid from liquefaction, coking, mild gasification and pyrolysis of coalscontains considerable amounts of alkylphenols with alkylbenzenes and alkylnaphtha lenes.To produce and purify useful chemicals, such as phenol, cresols, from coal-derived liquid,hydrocracking and hydrotreating of alkylphenol containing mixture are very importantprocess. We already reported the hydrocracking of coal-derived liquid to concentrateBTX, phenol and cresols from alkyl-substituted mixture and investigated the effect ofoxygen compounds addition on the hydrocracking. We found the dehydroxylation toproduce hydrocarbons and water was decreased by the addition of oxygen compounds,such as acetone, dimethylcarbonate(DMC), etc, comparing with the dealkylation. Theseare considered due to the strong interaction between OH group and DMC.In this study, we investigated the effect of DMC addition on the hydrotreating ofcoal-derived liquid using Ni-Mo/Al2O3 catalyst at 300-420 C. From the hydrotreating ofcoal tar-derived washing oil fraction, production ratio of phenol and cresols / BTXincreased 20-50 % by the addition of 10% DMC. This indicates the interaction betweenOH group and DMC also hindered the dehydroxylation in hydrotreating.The effect of other oxygen compounds and catalyst on the product distribution in thehydrotreating of coal-derived liquid and model mixture would also be discussedexperimentally and theoretically.