Abstract:  The reactor and regenerator in the 1.4 Mt/a RFCC unit at PetroChina Changqing Petrochemical Company are installed side by side with the same height. The reactor is designed with two-stage riser, and the regenerator is designed with fast fluidized bed and turbulent fluidized bed two-stage regeneration. During the operation of the unit, some problems emerged including the serious coking of the disengager, the large pressure drop in the main air and flue gas system and the high temperature hydrothermal deactivation of the catalysts. A series of effective measures were taken, such as the primary cyclone and secondary cyclone direct connection quick separation technology, the catalyst mixer technology at the bottom of riser and the improved fast fluidized bed and second dense bed regeneration technology, fundamentally solving the long cycle operation problem of the unit and improving the economic benefits.

Key words: fluid catalytic cracking unit/FCCU, fast fluidized bed and turbulent fluidized bed regeneration, disengager coking, direct connection quick separation, long cycle operation