Abstract: The commercial application of the new DPC alkali catalytic technology developed by China National Offshore Oil Corporation (CNOOC) in CNOOC Zhongjie Petrochemical Co., Ltd. was introduced. The DPC reacting process has the characteristics of weak hydrogen transfer, weak aromatics condensation and "cutting and cracking" of macromolecular aromatics with alkyl side chain. It has strong adaptability to crude oil, and is suitable for processing meta-cycloalkyl crude oil and inferior heavy oil. At the stage of industrial application, the blending amount of atmospheric residue in feed was gradually increased without significant adjustment of feed volume, reaction temperature, catalyst activity and catalyst/oil ratio. The calibration results showed that the mass yield of liquefied petroleum gas increased by 4.93 percentage points, the coke yield decreased by 0.95 percentage point, the volume fraction of propylene increased by 13.77 percentage points, and the volume fraction of（C₃+C₄）olefins increased by 5.29 percentage points when the slag content was 70.5% and the storage of DPC catalyst was 70%; the mass yield of liquefied petroleum gas increased by 3.66 percentage points, the coke yield increased by 0.30 percentage point, the volume fraction of propylene in liquefied gas increased by 11.33 percentage points, and the volume fraction of （C₃+C₄）olefins increased by 8.44 percentage points when the slag content was 91% and the storage of DPC catalyst was 91%. The unit has been running smoothly for 6 months after calibration, and the successful application of this technology provided a technical guarantee for the crude oil to chemicals technology with independent intellectual property rights of CNOOC.

Key words: catalytic cracking, DPC alkali catalysis, coke, liquid petroleum gas, propylene