Abstract: In order to solve the problem of large environmental protection pressure in the process of styrene tar treatment, the styrene tar was sent to a delayed coking unit for recycling. The results showed that the styrene tar was not suitable to be reprocessed during the cooling coke period due to discoloration of the cold-cut coke water and odor during coke removal. The method of recovering styrene tar during the production of the coke drum was feasible, but the recovering styrene tar would affect the side line of the fractionation column in coking unit, so it was necessary to control the amount and time of recovering styrene tar, optimize the process operation, maintain the equipment regularly, and analyze the content of styrene tar in various products of the delayed coking unit, cold-cut coke water, and sulfur-containing wastewater periodically. The problem of equipment and pipeline blockage during the recycling process has been solved through continuous optimization of process and equipment conditions. Furthermore, the unit operated smoothly after the recycling process. The styrene tar was successfully decomposed into the products of the delayed coking unit by reprocessing.

Key words: styrene tar, delayed coking, recycling