Abstract: Based on the investigation results of the current situation of the resource utilization of styrene tar in China, according to the physicochemical properties, composition, thermal reaction curve, product distribution, crystalline and polymer composition of styrene tar, a scheme of introducing styrene tar into regenerator of DCC unit to produce steam was proposed.Based on the development plan of the enterprise and the characteristics of the unit structure, the pilot-scale and pilot-scale simulation tests were carried out, the feasibility of the scheme was demonstrated, and the advantages and disadvantages of the scheme were analyzed. From July to September, 2022, the commercial test of this scheme was successfully carried out on a 2.2 Mt/a industrial DCC unit. The results showed that 8-10 t of superheated steam could be generated by burning 1 t of tar. When the capacity of styrene tar treatment was 3 kt/a, it would not affect the smooth operation of DCC unit and the emission of harmful substances in the recycled flue gas, and would increase the economic benefit of enterprises over 20 million yuan/a，so that utilization of styrene tar with high toxicity is legal, efficient, green and high value.

Key words: styrene tar, polymerization inhibitor, hazardous waste, deep catalytic cracking, resource utilization