低压操作对延迟焦化产品分布和性质的影响

Effect of low operation pressure on distribution and properties of delayed coking products

采用自主设计的中型延迟焦化装置,考察了降低焦炭塔顶操作压力对延迟焦化过程的影响。试验结果表明,在进料量、炉出口温度、注汽量、循环比和充焦时间等操作条件基本一致的情况下,焦炭塔顶操作压力由0.17 MPa降低到0.11 MPa时,焦化蜡油的产率提高了3.75%,液体产品产率提高了1.87%,气体和焦炭的产率降低;同时随着操作压力的降低,产品焦化汽油和焦化柴油的性质基本一致,但焦化蜡油性质变差一些,主要表现在密度、残炭、沥青质、氮含量及金属等均有所升高,馏程95%点高出约15℃。

The effect of a lower operating pressure at coking tower top on the delayed coking process is studied on a self-developed pilot plant for delayed coking.The results show that the yield of coking gas oil increases by 3.75%,the yield of liquid products increases by 1.87%,and the yields of both gas and coke decrease when the operating pressure at coke tower top decreases from 0.17 MPa to 0.11 MPa but the operating conditions such as feed rate,furnace outlet temperature,steam injection rate,cycle ratio and coke charging time remains unchanged basically.As the operating pressure decreases,the properties of coking gasoline and coking diesel oil remains basically unchanged,but the properties of coking gas oil become worse.The density,carbon residue,asphaltene,nitrogen content and metals content of coking gas oil all increase,and its 95%points of distillation range is improved by 15℃.