Abstract:

Through the analysis on the composition of coking xylene, it is found that ethyl benzene and styrene is the main harmful impurity of xylene discoloration. The test result showed: the amount of acid addition should be controlled is 4.5%~5.0%,  the optimum washing temperature is 45~50℃,  and acid washing time is controlled at 7 minutes or longer. The measures of adding anti-oxidant into product, conducting secondary treatment and water washing can be taken for stabilization of product quality of xylene.