Abstract: This paper introduces the capacity expansion and optimization of the FCC gas fractionation unit of Daqing Refinery. The new high efficient trays, downcomer and other measures are adopted in the revamping. The transformation increases the capacity from 128.17 kt/a to 172.32 kt/a, and ensure the product quality. By using the top cycle oil from FCC unit as the hot source of the de-propane tower to heat the hot water instead of 1.0MPa steam, the comprehensive energy consumption of the unit is greatly reduced from 4303.7 MJ/t to 1634.4 MJ/t.

Key words: gas fractionation, FCC, capacity, energy consumption, optimization