Abstract: In order to enlarge the capacity and to reduce energy consumption of the fluidization catalytic cracking unit (FCCU), increasing the pressure of FCCU is a trend. However, the enhancement of the FCCU pressure is influenced by equipment manufacturing, capacity, regeneration mode and other factors. Meanwhile, the changes of pressure also affect the product distribution, energy consumption and the operation of mechanical equipment. So，the design of FCCU pressure should consider the processing scale, energy consumption, investment, equipment manufacturing, product slate, and conduct economic accounting and evaluation to get the optimum design proposal. In the selection of higher performance, downstream, fast bed-turbulent, oxygen-enriched regeneration mode, large and medium-sized FCCU are not constrained by equipment manufacturing, the regeneration pressure can be designed as 0.42-0.56 MPa; oversize FCCU is restricted by the manufacture of mechanical equipment, the pressure can be adjusted to 0.28-0.42 MPa.

Key words: FCC, pressure, design, product distribution, energy consumption