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On January 11, the successful commissioning of the 3.4 million tons per year disproportionation unit in Phase IV of the Daxie Petrochemical project, which began producing qualified products, marked a significant achievement in the operation of the aromatic compounds processing complex at Daxie Petrochemical. This success brought a positive start to the new year. The disproportionation unit is part of the comprehensive utilization project for distillate oils at Daxie Petrochemical; it utilizes disproportionation and alkylation techniques to convert low-value A9+ aromatic compounds into higher-value benzene and xylene products, using toluene and C9/C10 aromatic compounds as raw materials, under hydrogen and catalyst conditions. This process offers good economic and social benefits. To reduce equipment investment and operating costs, Daxie Petrochemical optimized its process equipment while ensuring that the quality of aromatic compound products remained satisfactory. As a result, one heavy aromatic hydrocarbon tower and one heavy aromatic hydrocarbon heater were removed, and 50 additional trays were added to the bottom of the xylene recovery tower, thereby saving approximately 13 million yuan in equipment costs. Additionally, with the elimination of the heavy aromatic hydrocarbon distillation system, the plant’s operational costs were reduced by about 14 million yuan per year. The disproportionation unit is equipped with an efficient flue gas waste heat recovery system, enabling the overall thermal efficiency of the heaters to reach 95%. During the design phase, Daxie Petrochemical utilized a recontact process for the disproportionation off-gases to remove most of the heavier components in those gases, including benzene and compounds with higher molecular weights (with a removal rate of over 80%), thereby extending the service life of the PSA adsorbents and further reducing the operating costs of the plant