渣油加氢技术进展

Advances in Residuum Hydrofining Technology

在重质原油加工利用上,加氢路线较脱碳路线的重油转化深度高、资源利用率高、经济效益好,但反应条件苛刻,流程复杂,能耗与投资比脱碳路线高。随着原油劣质化及日益严格的环保要求,渣油加工选择加氢路线会越来越多。固定床加氢工艺是通过不同床层的不同类型催化剂,对重油中的金属杂原子和硫、氮元素进行脱除以及对重组分进行改质,技术最为成熟。目前移动床加氢技术主要用作固定床工艺的前置反应器系统,是移动床与固定床的组合工艺。沸腾床加氢裂化原料油适应性广,反应器内温度均匀,催化剂可在线加入和排除,运行周期长,传质传热好,渣油转化率高,装置操作灵活。渣油悬浮床加氢裂化在建装置不多,然而其渣油原料转化率和轻油收率都比延迟焦化和沸腾床加氢裂化高得多,工业应用前景乐观。当渣油原料Ni+V小于120μg/g时,固定床渣油加氢是首选;为延长装置运转周期,可在固定床反应器前增加移动床反应器;加工高残炭、高金属含量减压渣油,沸腾床渣油加氢裂化技术是首选;悬浮床渣油加氢裂化为未来加工更重、更高金属含量及残炭的渣油做好了技术准备。

Compared to the decarbonizing route,the hydrofining route for heavy crude refining has deeper heavy oil conversion,more efficient utilization of resources and higher economic effiicency but requires more demanding reaction conditions,higher energy consumption and higher investment and involves more complex processes.With the use of increasingly heavy crude oil and stricter environmental requirements,more refiners will adopt the hydrofining route for processing residual oil.Fixed-bed hydrotreating technology uses different types of catalysts in different bed layers to remove metal heteroatom and sulfur and nitrogen elements and to upgrade heavy components.This technology is the most mature one.Mobile-bed hydrotreating technology is currently primarily used as the lead reactor system of fixed-bed technology and is a combination of mobile and fixed bed technology.Fluidized bed hydrocracking technology is characterized by wide feed oil adapability,even temperature distribution in reactors,inline addition and removal of catalysts,long operation cycle,good mass and heat transfer,high residuum conversion rate and flexible unit operation.China is building a small number of residuum suspension bed hydrocracking units.The residuum feedstock conversion rate and naphtha yield of such unit,however,are much higher than those of delayed coking and fluidized bed hydrocracking technologies.Therefore,there is a good prospect for industrial application of such technology.When residuum feedstock′s Ni+V is less than 120μg/g,the fixed bed hydrofining technology should be the first option.In order to extend the operation cycle of units,a mobile bed reactor can be added in front of a fixed bed reactor.When it comes to processing vacuum residuum with high contents of residual carbon and metal,the fluidized bed residuum hydrocracking technology should be be first choice.The suspension bed residuum hydrocracking technology paves the way for the processing of heavier residuum with higher contents of metal and residual carbon in the future.