Abstract: Based on the field data collected from a FCC unit in a refinery，an energy conservation process for the absorber-stripper-stabilizer system were developed，which is composed of pre-equilibrated process（PP），two stage condensation process（TSCP）and integration process（IP）. The performances of these three different processes were compared comprehensively with the conventional process（CP）using a process simulation approach. It was proved that all the three processes showed distinct energy conservation effect with comprehensive energy consuming reduction of 4.55% for PP，11.79% for TSCP and 17.82% for IP，which would lead to remarkable economic benefits. The fuel gas mass flow rate was decreased in PP while the quality of fuel gas was improved in TSCP and IP. Therefore，all the three processes were favorable to the recovery of the valuable heavy components in fuel gas. TSCP and IP were the better choice for improving the total C3 recovery rate，while PP and IP were better for the recovery of C4 components. Liquefied petroleum gas（LPG）and debutanized gasoline（DG）yields were improved in PP，while LPG yield was decreased slightly and DG yield was increased a little in TSCP.