蜡油加氢装置流程设计优化

蜡油加氢为加氢处理工艺的一类,是指通过加氢反应,原料油的分子大小不发生变化,或者只有小于10%的分子变小的那些加氢工艺。蜡油加氢装置主要以常减压蒸馏装置的减压蜡油(VGO)、焦化蜡油(CGO)为原料,通过加氢处理,脱除原料中的硫化物,以及部分脱除氮化物、氧化物及金属杂质。蜡油加氢装置是加工含硫及高硫原料、生产清洁燃料的重要装置之一,但其典型工艺流程能耗较高。优化蜡油加氢分馏系统流程,蜡油加氢操作能耗下降5kg标油/t,产品质量稳定。在中国石化系统11套蜡油加氢装置中,已经有6套装置对分馏系统进行了优化,某些装置更是改造成了蜡油及柴油可以互相切换的原料流程,半成品精制蜡油符合催化装置低硫原料要求,加工柴油时产品质量达到国Ⅳ标准。以某厂1.8Mt/a蜡油加氢装置流程优化为例,停用的较大设备有产品分馏塔、柴油汽提塔、分馏塔进料加热炉,共节约设备费用2090万元,每年节约燃料费用3700万元,每年实际创效2407.29万元。

Optimized Process Design for Wax Oil Hydrogenation Units

Wax oil hydrogenation is one of hydrotreating processes.In this hydrogenation process,the molecular dimensions of feed oil do not change or only less than 10% of the molecules become smaller.A wax oil hydrogenation unit primarily uses VGO or CGO from atmospheric and vacuum distillation units as feedstock and removes all sulfides and part of nitrides ,oxides and metallic impurities in the feedstock through hydrotreating. Wax oil hydrogenation units are important equipment used to process sulfur-containing and high-sulfur raw materials and to produce clean fuels.However,the classic process used in such equipment consumers large amounts of energy.Through the optimization of the process of the wax oil hydrogenation fractionating system, the energy use in the wax oil hydrogenation process can drop by up to 5kg of oil equivalent per ton of feedstock processed and the quality of products produced is stable.Of all 11 wax oil hydrogenation units of Sinopec, six have seen optimization of their fractionating systems and some have even been modified to allow feedstock switching over between wax oil and diesel fuel.Semi-finished refined wax oil satisfies catalytic units＇ requirements for low-sulfur feedstock and when processing diesel fuel,the units produced products meet- ing the national IV standard.Take the process optimization for a refinery＇s 1.8Mt/a wax oil hydrogenation unit for example.Major equipment stopped included a fraetionating column,a diesel fuel stripping column and a furnace used to heat the feed for the fractionating column.A total of 20.9 million yuan was saved in equipment cost.Annual savings of fuel cost reach 37 million yuan and annual economic benefits received from this optimization amount to 24.07 million yuan.