催化裂化装置加氢石脑油回炼对产品分布的影响

摘要

To ensure the production balance of the petrochemical plant and meet the requirements for production of gasoline of different specifications,the light and heavy naphthas are intermittently recycled to the FCCU,which are introduced into the unit 500 mm under the 1 st-stage reactor outlet after aromatization.With increasing of hydrotreated naphtha,the yields of dry gas,LPG,diesel and coke go down.The gasoline yield goes up,and the slurry oil yield is lightly elevated.But the olefins in the gas are obviously reduced,and gasoline octane number and aromatic content also fall down.It is found in the analysis of product distributions before and after the recycle operation that,with increasing recycled hydrotreated naphtha,the isomerization and hydrogenation reaction intensities go up gradually.Whereas,the intensity of FCC reaction is higher than that of thermal reaction.The good understanding of the impact of naphtha recycle on the reaction and product distribution provides a good reference for future operation optimization.%为确保全厂生产平衡,满足不同标号汽油产品生产要求,催化裂化单元间歇回炼轻质污油,轻质污油自距一段提升管反应器出口下方500 mm处经一次雾化后喷入.用加氢石脑油作为轻质油回炼期间,随着加氢石脑油回炼量的增加,干气、液化石油气、柴油和焦炭收率整体呈下降趋势,汽油收率明显提高,油浆收率也有小幅提高,但气体产品中烯烃含量明显降低,汽油辛烷值和芳烃含量也呈下降趋势.分析石脑油回炼前后产品分布以及相关表征公式发现,随着加氢石脑油回炼量的增加,异构化反应和氢转移反应强度逐渐增加,催化裂化反应强度始终高于热裂化反应.了解加氢石脑油回炼对反应过程和产品分布的影响,可以对未来生产调整提供数据参考.