加氢裂化装置轻烃回收工艺方案的对比分析

Comparison and analysis of light hydrocarbon recovery processes for hydrocracking unit

介绍了国内加氢裂化装置常见的轻烃回收工艺方案,以新建2.6 Mt/a加氢裂化装置为例,对先脱丁(丁烷)后脱乙(乙烷)和先脱乙后脱丁两种流程进行了模拟计算。对比分析模拟结果发现,先脱丁后脱乙流程和先脱乙后脱丁流程均可满足液化石油气的质量和收率要求,前者液化石油气收率达到98.6%,后者液化石油气收率达99.4%;与先脱丁后脱乙流程相比,先脱乙后脱丁流程的设备投资能减少12.0%,能耗能减少9.5%;从操作稳定性角度考虑,先脱乙后脱丁流程,能有效降低生成水合物的倾向,防止因生成水合物造成的塔顶回流系统堵塞。综合比较投资、能耗和操作稳定性,先脱乙后脱丁流程更具优势。

The common light hydrocarbon recovery processes for hydrocracking units in China are described.In a case study of a 2.6 MM TPY hydrocracking unit,the simulation calculations have been made for the two processes of de-butane before de-ethane and de-ethane before de-butane.The results of simulation show that both processes of de-butane before de-ethane and de-ethane before de-butane can meet the requirements of quality specifications of LPG,the former product yield is 98.6%,and the latter product yield is 99.4%.The comparison of the two processes indicates that,for the process of de-ethane before de-butane,the equipment investment and energy consumption are 12.0% and 9.5% lower than those of de-butane before de-ethane process.In consideration of operation stability,the de-butane before de-ethane process can effectively reduce the formation of water hydrate,and plugging by the water hydrate in the tower overhead recycle system is prevented.The comparisons of investment,energy consumption and operation stability confirm that the process of de-ethane before de-butane is more advantageous than the process of de-butane before de-ethane.