多产DCC原料的超劣质蜡油加氢裂化装置再生工业运转结果分析

Regeneration Performance of Hydrocracking Catalysts for Producing High Quality DCC Feedstock from Super Inferior VGO

某公司210×10^(4)t/a加氢裂化装置以加工密度超过932kg/m^(3),氮含量超过2000μg/g,BMCI值57左右的超劣质蜡油原料为主,生产加氢尾油,为多产丙烯的DCC装置提供原料,同时副产液化气、正己烷、重石脑油、喷气燃料、轻柴油以及导热油等。第一周期连续稳定运转2年6个月后根据全厂检修安排停工检修,对催化剂进行器外再生,工业运转结果表明:加氢精制剂与新鲜剂的脱硫、脱氮活性相当;加氢裂化再生剂的活性、选择性与新鲜剂相当。产品分布和产品性质达到或优于设计值,可满足长周期稳定生产需要。装置化工原料总收率达到70%以上,下游DCC plus装置丙烯收率可达到20.5%以上。各产品质量和收率均能达到设计值要求和考核指标,表明再生后活性恢复良好,通过精确调控各床层温升可以适应进料馏程、产品方案变化的影响。通过选择合适的催化剂、工艺、产品方案由超劣质进料大量生产优质化工原料在工业装置上具有可行性。

The 2.1 Mt/a hydrocracking unit of a company mainly processes the super inferior VGO with a density of higher than 932 kg/m^(3),a nitrogen content of higher than 2000μg/g and a BMCI value of around 57 to produce hydrocracker tail oil,providing raw materials for DCC unit for high propylene yield,and the by-products include liquefied petroleum gas,n-hexane,heavy naphtha,jet fuel,light diesel oil and heat transfer oil.After 2 years and 6 months′ continuous and stable operation of the first cycle,the unit was shut down for ex-site regeneration of catalysts according to the overhaul plan of the whole plant.The industrial operation results show that the desulfurization and denitrification activities of hydrofining catalyst are compara-ble to those of fresh catalyst,and the activity and selectivity of regenerated hydrocracking catalyst are comparable to those of fresh catalyst.Product distribution and product properties meet or exceed the design value,meeting the needs of long-term stable production.The total yield of chemical raw materials of the unit reaches more than 70%,and the propylene yield of the downstream DCC Plus unit reaches more than20.5%.The quality and yield of each product can meet the requirements of design value and the assessment indices,indicating that the activity of catalyst is restored after regeneration,and the changes in feed distillation range and product slate can be adapted to by accurately adjusting the temperature rise of each bed.It is industrially feasible to produce high quality chemical raw materials in large quantities from super low quality feedstock by selecting suitable catalyst,process and product slate.