加氢裂化装置开工初期重石脑油硫含量超标原因分析

Cause of off-specification of sulfur in heavy naphtha in the start-up period of hydrocracking unit

中国石油化工股份有限公司天津分公司炼油部2号加氢裂化装置在检修完成后重新开工时出现重石脑油硫质量分数严重超标,并出现波动,达到3.3μg/g以上,对下游连续重整装置产生了影响。经过一系列的分析排查及操作调整,确定了硫含量超标的原因是吸收稳定系统在开工初期冷油运时全馏石脑油一直未置换干净(硫质量分数达到180μg/g)造成的,通过采用系统置换措施使重石脑油硫质量分数控制在0.5μg/g以下。

The sulfur in heavy naphtha from No. 2 hydrocracking unit in the refinery of Sinopec Tianjin Petrochemical Company exceeded the specifications when the unit was restarted up after maintenance. The mass percentage of sulfur in heavy naphtha fluctuated and reached 3.3 ppm, which had an impact on the downstream continuous catalytic reforming unit. The analysis and operation adjustment have concluded that the off-specification of sulfur in heavy naphtha of No. 2 hydrocracking unit was caused by that the straight-run naphtha （ 180 ppm sulfur） in the absorption and stabilization system during the start-up has not been displaced completely in the early stage of start-up. The implementation of system displacement has controlled the mass percentage of sulfur in heavy naphtha below 0.5 ppm. The problem has been solved.