FCC汽油选择性加氢脱硫工艺优化设计

应用中国石化抚顺石油化工研究院（FRIPP）新开发的催化裂化（FCC）汽油选择性深度加氢脱硫技术（OCT-MD）：先将FCC汽油脱臭后切割为轻、重两个馏分,与FCC汽油直接先切割相比,轻馏分的总硫质量分数降低45％左右,硫醇硫质量分数≤10μg／g,RON损失较小,可以大大降低重馏分加氢脱硫深度,减少烯烃过度饱和造成的辛烷值损失。重馏分加氢脱硫反应采用低压操作方案有利于减少产品辛烷值损失,反应器入口压力最好不大于2．0MPa。采用二乙醇胺法处理后循环氢H2S质量分数≤100μg/g,不但可以提高脱硫率,还可大大减轻硫化氢与未反应的烯烃重排生成大分子硫醇的程度。根据中试和模拟计算结果,OCT—MD技术第一次在湛江东兴石油企业有限公司新建的FCC汽油选择性深度加氢脱硫装置上使用。

Optimization design of selective hydrodesulfurization process for FCC naphtha

In the selective hydrodesulfurization unit applying OCT-MD process newly developed by Fush- un Research Institute of Petroleum and Petrochemicals （FRIPP）, SINOPEC, FCC naphtha is first sweetened and then separated into two fractions i. e. LCN and HCN. As Compared to the FCC naphtha which is first separated into two fractions, the total sulfur of LCN is reduced by about 45%, the mercaptan content is less than 10 ppm and there is little loss of research octane number （RON）. The severity of hydrodesulfurization of HCN can be greatly reduced and the octane number loss from excessive olefin saturation is minimized. Lower pressure operation of hydrodesulfurization of HCN is favorable for the reduction of octane loss. The optimal inlet pressure of reactor is lower than 2.0 MPa. H2S content of recycle hydrogen can be reduced to less than 100 ppm via treatment by diethanolamine. Lower HE S content in recycle hydrogen can not only greatly improve HDS but also greatly reduce the large-molecule mercaptan production via reversion of H2S and olefin. The first commercial unit of OCT-MD process is built in Zhanjiang Dongxin Refining ＆ Chemical Co. , Ltd.