Abstract: ECC (Efficient Catalytic Cracking) process, which is based on the new technological concept of low temperature contact and high cat/oil ratio, mainly aims at reducing the yields of dry gas and coke, and increasing total liquid yield. A series of novel technologies was adopted in ECC process, such as heat exchange between catalyst and main air, pseudo-isothermal riser and system for adding fresh catalyst at tripping zone. The results of pilot plant tests showed that as compared with conventional FCC process, dry gas yield in ECC process was reduced by 0.68—1.04 percentage points, i.e. a more than 20% reduction; coke yield was reduced slightly; the total liquid yield was increased by over 1.0 percentage points. Meanwhile, the quality of the obtained gasoline in ECC process was improved, olefin content was reduced by more than 15%, and the SOx content in flue gas was also reduced by over 25%.

Key words: catalytic cracking, low temperature contact, cat/oil ratio, pseudo-isothermal riser