4.1Mt/a柴油加氢催化剂升级效果评价

Evaluation of catalyst upgrading in a 4.1 MM TPY diesel hydrotreating unit

为满足产品升级需求,在大检修期间对国内某4.1 Mt/a柴油加氢装置进行了升级改造。结合催化剂升级前后欧Ⅲ柴油生产工况,对催化剂空速水平、提高十六烷值能力、脱硫性能及装置氢耗进行了比较分析。分析结果表明:在生产欧Ⅲ柴油工况下,催化剂升级后,装置处理能力大幅提升,平均体积空速由2.0 h-1提高至2.5 h-1;催化剂提高十六烷值能力有所提高;催化柴油平均掺炼比例由4.43%提高至8.68%。与升级前相比,升级后平均反应温度提高了5～6℃,但升级后反应温度每提高1℃可将产品柴油的硫质量分数多降低20μg/g。装置氢耗有所增加,由79.6 m3/t上升至95.1 m3/t,氢耗增加的主要原因为:升级后的催化剂加氢饱和能力有所增强,环烷烃、芳烃等的侧链有一定程度的断链,产品中催化柴油比例有所提高。

To meet product upgrading requirements,the catalyst was upgraded in the overhaul of a 4.1 MM TPY diesel hydrotreating unit.The space velocity,the capability of cetane number enhancement and desulfurization performance of catalyst and hydrogen consumption of the unit were analyzed based upon the operating conditions of producing Euro-Ⅲ diesel before and after catalyst upgrading.The results of analysis demonstrate that,under the conditions of producing Euro-Ⅲ diesel and after catalyst upgrading,the unit capacity has been greatly increased and average volumetric space velocity is elevated to 2.5 h-1 from 2.0 h-1;The cetane-enhancement performance of the catalyst is greatly improved and blending ratio of FCC diesel is increased to 8.68% from 4.43%;Although the average reaction temperature is increased by 5-6 ℃ after catalyst upgrading,the 1 ℃ elevation of reaction temperature will reduce S in product diesel by 20 ppm.The hydrogen consumption of the unit is increased from 79.6 m3/t to 95.1 m3/t.The main causes of hydrogen consumption increase are the improved hydro-saturation performance of upgraded catalyst,chain breaking of naphthenes and aromatics,and increased FCC diesel in feedstock.