Abstract:

Aiming at the problems of white smoke and salt rain in the existing FCC flue gas sodium alkal washing wet desulfurization and dust removal unit,a wet flue gas eliminating white smoke and salt rain purification technology was developed,and it was applied in the No.2 FCC flue gas treatment unit of a petrochemical enterprise.Through transforming the water droplet separator section of the original tower,such as removing the water droplet separator,replacing it with a water washing spray section,an efficient incremental demis section and a flue gas reheat module,so as to achieve the purpose of deep dust removal,defogging,and eliminating white smoke of flue gas,and complete the demonstration of FCC flue gas eliminating white smoke and salt rain purification.This technology does not increase the site area of the unit,and has little impact on the absorption and spraying of the original flue gas desulfurization tower.The condensed water obtained by heating steam condensation is returned to the waste heat boiler,realizing 100%recovery of heating steam,and minimizing the increase in energy consumption.Compared with before the transformation,the annual emission reduction is about 60.01 tons of soluble salt,about 0.38 tons of escape ammonia,about 6.79 tons of NOx,18.48 tons of catalyst dust,about 11.2 tons of SO₂and about 20.98 tons of SO₃.

Key words: FCC unit, eliminating white smoke, salt rain purification, water droplet separator, phase change coagulation, flue gas reheat module, droplet removal rate

摘要：

针对催化裂化(FCC)烟气钠碱洗涤湿法脱硫除尘装置存在的白烟及盐雨等问题，开发了湿烟气消白及盐雨净化技术，并将其应用于某企业2号FCC烟气处理装置。通过对原塔的水珠分离器段进行改造，拆除水珠分离器，更换为水洗涤喷淋段、高效递增除雾段和烟气再热模块，以达到烟气深度除尘、除雾及消白的目的。该技术不增加装置占地面积，对原烟气脱硫塔吸收和喷淋影响小，加热蒸汽冷凝得到的凝结水返回余热锅炉，实现了加热蒸汽100%回收，能耗增加量降至最低；与改造前相比，每年可溶性盐减排量约60.01 t,逃逸氨减排量约0.38 t, NO_x减排量约6.79 t,催化剂粉尘减排量约18.48 t, SO₂减排量约11.2 t, SO₃减排量约20.98 t。

关键词: 催化裂化装置, 消白烟, 盐雨净化, 水珠分离器, 相变凝聚, 烟气再热模块, 雾滴脱除率