催化裂化装置催化剂铁中毒现象分析与对策

Problem analysis and countermeasures of catalyst iron poisoning in FCC unit

分析了3套催化裂化装置近期出现催化剂铁中毒现象的原因并提出了应对措施。铁中毒现象出现后装置的表现是:①平衡剂堆积密度降低;②再生器藏量降低,中国石化扬子石油化工有限公司2号催化裂化装置(扬子2号催化)烧焦罐藏量最高降低幅度达50%;③再生稀相密度增加,中国石油化工股份有限公司镇海炼化分公司蜡油催化装置(镇海蜡油催化)稀相密度由7 kg/m^3上升至20 kg/m^3;④完全再生装置出现尾燃;⑤铁元素在催化剂表面形成壳层状结构;⑥影响产物收率,扬子2号催化干气、轻循环油、油浆及焦炭产率增加,液化石油气、汽油产率降低;镇海蜡油催化轻循环油、油浆及焦炭产率增加,干气、液化石油气及汽油产率降低。主要应对措施:应用原油脱铁剂等技术从源头控制装置进料铁含量;采用抗铁催化裂化催化剂;提高催化剂置换率及剂油比等。

Reasons for catalyst iron poisoning in 3 sets of FCCU are analyzed and countermeasures are put forward. After the occurrence of iron poisoning, the following problems exist in the device: ①the catalyst bulk density is reduced;②the inventory of regenerator is reduced, and the maximum reduction of burnt tank storage capacity in SINOPEC Yangzi Petrochemical Co., Ltd.(Yangzi 2^#) is 50%;③the density of regenerated dilute phase is increased and the dilute phase density of SINOPEC Zhenhai Refining & Chemical Co., Ltd.(Zhenhai) is increased from 7 kg/m^3 to 20 kg/m^3;④the tail combustion in a complete regenerative unit is occurred;⑤iron element is mainly formed a shell-like structure on the surface of the catalyst;⑥the yields of catalytic dry gas, LCO, slurry and coke increase, while the yields of LPG and gasoline decrease in Yangzi 2^#;and the yields of LCO, slurry and coke increased, while the yields of dry gas, LPG and gasoline decreased in Zhenhai. The main countermeasures are the application of crude oil de-ironing agent and other technical to control the iron content of feedstock, the use of anti-iron FCC catalyst, increase the catalyst replacement rate and improve the ratio of the catalyst to oil, etc.