Abstract: In order to increase the production of liquefied petroleum gas (LPG) and propylene to meet the market demand, the production process of the catalytic cracking unit(Ⅱ) was adjusted from MIP technology to MIP-CGP technology, and the adaptive capacity expansion transformation was carried out for a series of gas separation units. After revamping, the operation of each unit was smoothly, the output of LPG was increased from 85.85 t/h to 117.20 t/h, and the yield was increased by 3.00 percentage points; the yield of propylene was increased from 24.89 t/h to 36.04 t/h, and the yield was increased by 1.26 percentage points. The product quality fully meets the requirements, greatly improving the economic benefits of the company. The MIP-CGP technical transformation provides a demonstration for improving the production of LPG and propylene in oil refining enterprises.

Key words: catalytic cracking, MIP-CGP, liquefied petroleum gas, proplyene