裂解汽油加氢装置精馏塔双股进料的模拟及改造

Simulation and Revamp of the Double-feed Distillation Tower of the Cracking Gasoline Hydrogenation Unit

裂解汽油加氢装置的原料油分为轻、重粗汽油,两股汽油馏分组分差异较大。传统流程的轻重裂解汽油混合冷却进罐区,导致一系列用能瓶颈,包括热量的冷却损失、脱C_(5)塔内物料的返混、重沸器能耗增加、罐区VOC排放增加等。采用双股进料优化可消除上述瓶颈。对此进行模拟分析,结果显示,改造后裂解汽油加氢装置的脱C_(5)塔重沸器负荷大幅下降,但回流比也有所增加。某石化的裂解汽油加氢装置进行了脱C_(5)塔双股进料节能改造,改造后轻、重汽油分别从塔上部和下部进料,进料温度从原来的32℃分别提高至77、86℃,重沸器蒸汽单位进料的蒸汽用量下降了24.5%,节能效果显著。

The feedstock of the ethylene cracking gasoline hydrogenation unit is divided into two streams:light and heavy naphtha,which have significant differences in their fraction distributions.In the conventional process,the mixture of light and heavy cracked gasoline is cooled and stored in the tank area,leading to a series of energy bottlenecks,including cooling losses of heat,remixing of materials in the depentanizer tower,increased energy consumption in the reboiler,and increased VOC emissions from the tank area.The utilization of dual-feed optimization can eliminate the above bottlenecks.A simulation analysis is conducted,and the results shows that the load of the reboiler of the depentanizer tower of ethylene cracking gasoline hydrogenation unit significantly decreased,while the reflux ratio increased to some extent.A petrochemical company carried out an energy-saving revamp of the depentanizer towers by implementing dual-feed optimization for the ethylene cracking gasoline hydrogenation unit.After the revamp,light and heavy gasoline are respectively fed into the towers from the upper and lower parts,and the feed temperature was increased from the original 32℃to 77℃and 86℃.The steam consumption per unit of feed in the reboiler decreased by 24.5%,which has significant energy-saving effect.