镇海炼化4号柴油加氢装置流程模拟应用

镇海炼化4号柴油加氢装置设计处理能力为300×104t/a,进料由焦化汽柴油、催化柴油、直馏柴油组成,装置反应部分采用炉前混氢流程,设置热高分、热低分流程。热低分油、冷低分油混合后进入脱硫化氢汽提塔(T-2101)。装置分馏部分为双塔汽提流程。从2002年开工至今,运行情况总体良好。装置希望通过流程模拟,对目前运行参数和换热流程进行优化,改善装置运行工况。应用Aspen Plus软件,对装置分馏部分进行流程模拟,得到了与装置实际操作工况接近的理想模型,为装置优化操作、节能降耗及寻找生产瓶颈提供依据。本次模拟目标为初步应用,主要以模型为指导,研究增产石脑油时分馏塔顶回流比对汽油干点、柴油闪点温度的影响,以及提高T-2101塔汽提蒸汽量对塔顶硫化氢量的影响,实现了汽油产量增加2.37%和T-2101塔汽提蒸汽降低0.1t/h的目标。实施流程模拟优化后,装置全年共产生经济效益132.6万元,表明镇海炼化4号柴油加氢装置流程模拟优化取得成功。

The Application of Process Simulation Technology in Sinopec Zhenhai Refining and Chemical Co.'s No.4 Diesel Hydrogenation Unit

Sinopec Zhenhai Refining and Chemical Company′s No.4 diesel hydrogenation unit has a designed processing capacity of 300×104t/a.Its feedstock consists of coke gasoline and diesel fuel,catalytic diesel and straight-run diesel fuel.The reaction section of the unit uses a process in which hydrogen is blended in before the heating furnace.The unit is also equipped with a hot high-pressure separator and a hot low-pressure separator process.Hot low-pressure separator oil and cold low-pressure separator oil are blended before entering the desulfhydrylation stripper(T-2101).The fractionation section of the unit uses a dual-column stripping process.Since it started operation in 2002,the unit has overall been running well.The company hoped to use process simulation to optimize the operating parameters and heat exchange process to improve the operation of the unit.Using the Aspen Plus software,technicians established an ideal model with parameters close to the actual operating conditions of unit.The technicians hoped to use the modeling results to find measures for optimizing the operation of the unit,saving energy and identifying production bottlenecks.The object of this modeling is initial application and the simulation is primarily aimed to study the influence of the reflux ratio at the top of the fractionation column on gasoline dry point and diesel flash point temperatures when raising yields of naphtha as well as the influence of raising the amount of stripping steam in the T-2101 column on the amount of hydrogen sulfide at the top of the column.As a result,the objectives of raising gasoline output by 2.37% and reducing the amount of stripping steam in the T-2101 column by 0.1t/h were achieved.Annual economic benefits from the process simulation-based optimization amounted to 1.326 million yuan.This means that the process simulation and optimization for Zhenhai Refining and Chemical Company′s No.4 diesel hydrogenation unit were successful.