加氢裂化装置换热器结盐原因分析

针对中国石油锦州石化公司加氢裂化装置经常出现高压换热器结盐情况,特别是掺炼焦化蜡油后结盐速率明显加快的问题,分析了该装置换热器中盐垢的主要成分,测定和监测了原油、加氢裂化原料油、重整氢、焦化蜡油中的杂质元素含量。结果表明:加氢裂化换热器中的盐垢主要为氯化铵;加氢裂化原料油的氯含量有时超标是高压换热器管程结盐的主要原因;焦化蜡油中氮含量高,加氢裂化原料掺焦化蜡油后,加氢裂化原料中氮含量超过了原料控制指标是高压换热器结盐速率加快的主要原因。

ANALYSIS OF SCALING FORMATION IN HYDROCRACKER HEAT EXCHANGERS

Salt scaling frequently occurred in the hydrocracking unit in PetroChina Jinzhou Petrochemical Company. The scaling was faster especially after coker gas oil was added into the feed. The contents of heteroatoms in crude oil, vacuum gas oil, coker gas oil, and reformate hydrogen were determined. It is verified that the main component of the scale is ammonium chloride and the scaling is caused by the excess chlorine and nitrogen content in the hydrocracking feedstocks, and high nitrogen content in feed from coker gas oil accelerates the trend of scaling formation.