关键词: 乙烯；丙烯；增强型催化裂解技术（DCC-plus）, 工业应用；产品灵活性

Abstract: Enhanced Deep Catalytic Cracking (DCC-plus) process, which uses combined reactors with multiple reaction zones and was developed by Research Institute of Petroleum Processing (SINOPEC), is a flexible technology for producing light olefins from heavy oils. Not only different reaction zones in this process could be controlled precisely, but also the recycling and cracking process of C₄ distillates and light gasoline fraction were utilized. The above two processes can enhance both the primary cracking of heavy oils and the secondary cracking of gasoline fraction. All these improvements result in high propylene yield and less dry gas and coke yields. DCC-plus process has been successfully applied in several commercial plants. For example, in Ningbo Daxie Petrochemical Limited Company (CNOOC), the 2.2 Mt/a DCC-plus unit achieved good application results with ethylene yield of 5.16% and propylene yield of 21.55%. DCC-plus process demonstrates a good flexibility of its products, which can be switched flexibly through adjusting the operating parameters and catalyst formulation. DCC-plus process provides a reliable way for oil refinery transformation and revamp.

Key words: ethylene, propylene, deep catalytic cracking(DCC-plus), commercial application, products flexibility