同轴式催化裂化装置催化剂Ca中毒现象分析及应对

An Analysis of Calcium Catalyst Poisoning in Coaxial Catalytic Cracking Unit and Countermeasures

同轴式催化裂化装置催化剂Ca中毒后,再生器出现流化异常、跑剂、产品收率变差等现象,原料、平衡催化剂中的Ca含量均明显上升,内部含块状物。通过加强原料性质监控,调整闪蒸系统原料种类,或及时调整闪蒸进料比例;控制沉降器、再生器压力,增加待生线路推动力,缓解沉降器汽提段波动情况;调整再生器藏量,提高实际催化剂的流化量,缓解再生器催化剂扬尘现象;控制再生器旋分器入口的再生风量,减少催化剂的跑损;三旋废剂罐每天安排一次卸剂,避免危及烟机安全运行;催化剂Ca中毒前期,及时对平衡剂进行较大量的置换,解决操作上的燃眉之急,待再生操作稳定后,逐步提高新鲜剂加注速度,提高催化剂活性中心数,同时每天加注重油裂解强化助剂,提高平衡剂活性,确保催化剂良好的裂化效果,力保轻液收率稳定。采取上述措施后,装置逐步趋于平稳,产品分布逐渐趋于正常,为相关装置快速、准确判断、解决催化剂Ca中毒问题提供经验参考。

Zhou Zhihang;SINOPEC Luoyang Company; Following calcium catalyst poisoning,the regenerator of Sinopec Luoyang Company ′s coaxial catalytic cracking unit experienced abnormal fluidization,catalyst leak and lower product yield.The contents of Ca in the feedstock and balance catalyst both increased significantly and there were also lumps inside.In order to resolve these issues,the following measures were taken ：Strengthening the monitoring of feedstock properties,adjusting the types of feedstocks for the flash distillation system,or timely adjusting the proportion of feedstocks for flash distillation,controlling the pressure of the settler and regenerator,increasing the driving force for the line for regeneration to alleviate the fluctuations in the stripping segment of the settler,adjusting the regenerator′ s reserve capacity,increasing the actual fluidization of catalyst to reduce fugitive catalyst powder from the regenerator,controlling the regeneration air flow at the inlet of the regenerator cyclone separator to reduce catalyst loss,arranging a daily discharge of catalyst for the waste catalyst tank of the three-stage cy-clone to prevent the waste catalyst from endangering the safe operation of the flue gas turbine and timely re-placing the balance catalyst on a large scale during the first stage of calcium catalyst poisoning.After the re-generation operation stabilized,technicians gradually increased the speed of adding fresh catalyst to raise the number of catalyst active centers.At the same time,they injected additives to reinforce heavy oil cracking daily to improve the activity of the balance catalyst to ensure good cracking effect of catalyst and stable yields of light liquids.As a result of the above measures,the operation of the unit gradually stabilized and product distribution gradually returned to normal.These measures could be used as a guide to quickly and accurately diagnose and resolve calcium catalyst poisoning.