关键词: 催化裂化装置, 第二再生器, 旋风分离器, 硫酸钙积聚, 结垢, 堵塞, 电脱盐, 低氧含量

Abstract:

During the operation of the domestic FCC unit with two-stage regenerator, the separation efficiency of the first and second stage cyclone separators of the second regenerator abruptly decreased. It appeared that the average particle size of the equilibrium catalyst and the fines from the third stage cyclone separator increased, the fine content of the equilibrium catalyst decreased, and the catalyst loss increased. In the course of the inspection of the unit, it showed that the joint of the ash hopper and cyclone leg of the second stage cyclone separator of the second regenerator was severely fouled, as well as the external wall of the first and second stage cyclone separators of the second regenerator, and the conical outlet of the third stage cyclone separator of the second regenerator. The results showed that the content of calcium sulfate in the fouling samples from the second stage cyclone separator internal wall and the external wall of the first and second stage cyclone separators exceeded 70%, while the fouling of the third stage cyclone separator and the blades of the flue gas turbine was mainly catalyst fine powders and metallic oxides. The oxygen-rich regeneration environment of the second regenerator, the revamp for capacity expansion leading to the increase of catalyst concentration in the dilute phase and the increase of the content of iron and calcium in crude oil may account for the accumulation of calcium sulfate.

Key words: FCC unit, the second regenerator, cyclone separator, calcium sulfate accumulation, fouling, blockage, electric desalting, low oxygen content