Mix temperature control enhances FCC flexibility in use of wider range of feeds

Two-stage regeneration, improved feed injection, and control of the feed-catalyst mix temperature have resulted in a step forward in fluid catalytic cracking (FCC) technology. Combined with catalyst developments, these improvements pave the way for feeds previously considered too tough for the FCC process, or to new modes of operation that maximize distillate production, improve gasoline octane, etc., all under attractive economic conditions. The desire to process heavier and more contaminated resids, prone to heavy coke formation, has caused the metallurgical temperature limits (770/sup 0/C) of the FCC regenerator to be reached. A new approach, in development at Total since 1981, allows the regeneration temperature to float and stabilize at the level required to maintain FCC unit thermal balance. Temperatures up to 900/sup 0/C are feasible.