重油催化裂化分馏塔结盐的分析与对策

ANALYSIS OF SALT DEPOSITION PROBLEM IN THE FRACTIONATOR OF HEAVY OIL CATALYTIC CRACKER AND COUNTERMEASURES

本文对洛阳石油化工总厂重油催化裂化分馏塔结盐问题进行了剖析。认为催化裂化原料中的氯化物在反应条件下水解生成ＨＣｌ，井与原料中的氮化物反应生成的ＮＨ３进行反应生成ＮＨ４Ｃｌ，ＮＨ４Ｃｌ在分馏塔上部低温部位结晶溶解于水相中形成半流体而堵塞降液管，造成冲塔打乱正常生产。原油中有机氯的存在加剧了分馏塔的结盐速度。在解决结盐问题上，总结了不停工进行分馏塔洗塔的措施；并成功地实现了重油电脱盐工业化，使常压重油含盐量成倍减少。通过这些措施的实施，基本上解决了这一生产难题，并使结盐周期显著延长。

The problem of salt deposition in the fractionator of the heavy oil catalytic cracking unit in Luoyang General Petrochemical Works is analyzed. It shows that the chlorine compounds in cracking feed hydrolyze under cracking conditions to form HCl,which in turn reacts with NH3(formed from the nitrogen compounds in the feed)to form NH4Cl;NH4Cl crystallizes at the upper,low temperature portion of fractionator and dissolve in the water phase to form a sent-fluid,which plugs the down-pipe and results in abnormal operation of the fractionator. The existance of organo-chlorine compounds in the crude oil accelerates the rate of salt deposition. To solve this problem, we have summed up the experiences in tower washing and implemented electric desalting of the heavy oil,so that the salt content of the atmospheric bottom is dramatically reduced. By these measures the problem is basically solved and the salt deposition period is significantly prolonged.