FCC汽油选择性加氢脱硫单元产品辛烷值的影响因素分析

针对中化泉州石化有限公司1.6 Mt/a催化裂化汽油选择性加氢脱硫装置开工初期产品汽油辛烷值损失严重的问题,考察了选择性加氢（SHU）反应器的出口压力、SHU反应器温升以及汽油分馏塔侧线抽出率等因素对产品汽油辛烷值损失的影响.结果表明,随着SHU反应器出口压力或SHU反应器温升的增加,SHU催化剂活性增加,但选择性降低,辛烷值损失增加;当SHU反应器出口压力2.0 MPa、SHU反应器温升5.0℃、进料量130 t/h、氢油体积比12时,SHU反应器辛烷值增加约0.1单位;SHU反应器出口压力对轻汽油中的硫醇脱除率影响较小,SHU反应器温升对其影响较大;在控制轻汽油中总硫质量分数小于80 μg/s的条件下,提高汽油分馏塔侧线抽出率,有利于提高出装置的调合汽油组分的辛烷值.与试验前比较,操作条件优化后,能耗降低约10 391.7 MJ/h,SHU单元辛烷值增加了1.5单位,节省了投资,增加了经济效益.

Analysis of factors affecting product octane number of FCC gasoline selective hydrogenation unit

In the 1.6 MM TPY selective hydrodesulfurization unit （SHU） in SINOCHEM Quanzhou Petrochemical Co.,Ltd.,there was serious octane loss of product gasoline at the start of running.To solve this problem,the impacts of outlet pressure of SHU reactor,SHU reactor temperature rise and sidedraw rate of gasoline splitter on gasoline octane loss are studied.The results show that,with the rise of SHU reactor outlet pressure and reactor temperature,the SHU catalyst activity is increased,the selectivity is lowered and octane loss is raised.When the reactor outlet pressure is 2.0 MPa,SHU reactor temperature rise is 5 ℃,the feed rate is 130 t/h and volumetric hydrogen to oil ratio is 12,the octane number of selective hydrogenation unit is increased by 0.1 unit.There is little impact of SHU reactor outlet pressure on the removal rate of mercaptan in gasoline,while the SHU reactor temperature rise has a greater impact on it.If the total sulfur of light gasoline is controlled to be less than 80 ppm,the mixed gasoline＇ s octane number can be improved with the increase of side pumping rate of gasoline splitter.As compared with the operation before the test,the optimization of operating conditions has reduced the energy consumption by about 10 391.7 MJ/h,increased the octane number by 1.5 units,saved capital investment and increased the economic benefits of the company.