半再生重整催化剂氮中毒原因分析及对策

CAUSE ANALYSIS AND COUNTERMEASURES OF NITROGEN POISONING OF SEMI-REGENERATIVE REFORMING CATALYST

某炼油厂450 kt/a半再生重整装置于2021年10月因精制油氮含量超标而造成SR-1000重整催化剂发生氮中毒,导致重整催化剂活性快速下降,重整汽油辛烷值降低。通过系统分析重整精制油氮含量超标的原因,发现主要是由于防腐中和缓蚀剂选择不当使预加氢原料氮含量增加,以及预加氢催化剂脱氮活性低。在工业应用实践中,采取优选合适的缓蚀剂并控制注入量、调整预加氢单元反应及蒸发塔操作条件、采用高活性脱氮预加氢催化剂等针对性措施,可有效解决精制油氮含量超标问题。重整催化剂受到氮污染后,活性恢复能力强,在精制油杂质含量合格的情况下,催化剂活性仍能恢复到受冲击前的水平。

The activity of the reforming catalyst SR-1000 was rapidly decreased and the octane number of the reforming gasoline was reduced because of the nitrogen poisoning of the reforming catalyst SR-1000 caused by excessive nitrogen content of the refined oil in the 450 kt/a semi-regenerative reforming unit of a refinery in October 2021.Through the systematic analysis of the reasons for the excessive nitrogen content of refined oil,it was found that the excessive nitrogen content of the refined oil was mainly caused by both the improper use of anti-corrosion neutralizing inhibitor which increased nitrogen content in the pre-hydrogenation feedstock and the low denitrification activity of pre-hydrogenation catalyst.In the practice of industrial application,such measures as selecting suitable corrosion inhibitor and controlling the injection amount,adjusting pre-hydrogenation unit reaction and operating conditions of the evaporation column,and using high-activity denitrification and pre-hydrogenation catalysts,etc.could effectively solve the problem of excessive nitrogen content in refined oil.The activity of the reforming catalyst could be recovered even if the impurity content of the refined oil was qualified.