关键词: 催化裂化装置, 再生器, 尾燃, 烧焦温度, 停留时间, 氧分压, Crosser格栅

Abstract:

Since March 2021, the phenomenon of after-burning has continued to occur in the regenerator of 800,000 TPY FCC unit in a refinery. This paper discusses the phenomenon from multiple aspects such as coke burning temperature, catalyst residence time, and oxygen partial pressure, according to the coking theory of coke burning drum, and comparing the operating parameters of multiple sets of the same type units. It is pointed out that the short residence time of the catalyst in the coke burning drum causes incomplete combustion of the catalyst, and the large amount of CO generated encounters excess oxygen in the dilute phase, leading to after-burning of the dilute phase of the regenerator. When the coke burning drum storage capacity is increased to 45 t/h, the residence time is extended to 81 seconds, the dilute phase temperature of the regenerator is reduced to 721 ℃, the temperature difference between the dilute phase and the dense phase is reduced to 20 ℃, and the phenomenon of after-burning of the regenerator is effectively controlled.

Key words: FCC unit, regenerator, after-burning, coke burning temperature, residence time, oxygen partial pressure, Crosser grille