重整生成油烯烃含量高的原因分析

Analysis of the cause of high olefin content in reformate

中海油气(泰州)石化有限公司1.0 Mt/a逆流移动床连续重整装置采用中国石化自主开发的催化剂逆流移动床工艺技术,以直馏石脑油和加氢裂化重石脑油为原料,生产C^+_6组分(辛烷值RON为103)的重整生成油。装置运行中存在因生成油烯烃含量较高,导致下游芳烃抽提装置白土更换频繁、换剂费用较高以及产生的危险废物难以处理的问题。从重整进料、再生催化剂注氯量、重整反应机理、重整生成油烯烃组成、重整反应温度等方面对装置进行了综合分析,结果表明:调整重整反应苛刻度不能大幅度降低重整生成油中的烯烃含量;在脱戊烷塔前增设液相加氢反应系统替代白土脱除烯烃,可以保证芳烃产品的溴指数及其他指标合格,重整生成油溴指数低于200 mgBr/(100 g),芳烃产品溴指数低于20 mgBr/(100 g)。

The 1.0 MM TPY counter-flow moving-bed continuous reforming unit of CNOOC Oil&Gas(Taizhou)Petrochemical CO.,Ltd.,uses catalytic counter-flow moving-bed process which is independently developed by SINOPEC.Its feedstocks are straight-run naphtha and heavy naphtha of hydrocracking process.Because of the high olefin content in reformate,clay in downstream aromatics extraction unit need to be replaced frequently,the replacement cost is high and hazardous waste produced is hard to treat.The unit is analyzed synthetically in terms of reformed feed,amount of chlorine injection of regenerated catalyst,reformed reaction mechanism,olefin composition of reformate and reforming reaction temperature.The results show that adjusting the severity of reforming reaction can’t reduce the olefin content in reformate drastically,adding liquid-phase hydrogenation reaction system in front of depentanizer instead of clay to remove olefin can guarantee the qualification of bromine index of aromatic hydrocarbon products and other index.Bromine index of reformate is less than 200 mgBr/(100 g).Bromine index of aromatic hydrocarbon products is less than 20 mgBr/(100 g).