柴油加氢装置分馏系统模拟及进料温度影响分析

柴油加氢精制是加工劣质原料和生产清洁柴油的重要途径,但由于加氢过程涉及高温、高压、临氢,反应产物组成复杂,柴油加氢装置分馏系统能耗较高。Aspen Plus是对生产装置进行稳态模拟的大型通用流程模拟系统,可为装置优化操作、节能降耗、寻找生产瓶颈提供指导。应用Aspen Plus流程模拟软件,建立了某120×104t/a柴油加氢精制装置的分馏系统流程模拟,研究了汽提塔的进料温度、汽提蒸汽量对汽提塔底物流H2S及H2O含量、分馏塔重沸炉的影响,同时分析了提高分馏塔进料温度对塔的气-液相负荷、汽柴油产量和重沸炉负荷产生的影响。通过对以上研究结果的综合分析发现,提高汽提塔进料温度可以强化塔的汽提效果,降低汽提蒸汽用量和分馏塔重沸炉热负荷;提高分馏塔进料温度,可使塔内气-液相负荷分布更加平均,操作稳定性增加,汽油产量增加、柴油产量减小,提高装置的经济效益,显著降低重沸炉负荷。当分馏塔进料温度提升15℃时,可节省燃料气209kg/h。

The Simulation of Fractionation System of Diesel Hydrotreating Unit and Analysis of Effect of Feed Temperature

Diesel hydrotreating is an important approach to processing low quality of feedstock and producing clean diesel fuel.However,the energy consumption of the fractionation system of a diesel hydrotreating unit is very high due to the involvement of high temperature ,high pressure ,hydrotreating and complicated composition of reaction products.The Aspen Plus is a large general-purpose process simulation system used for steady- state simulation of production units and can help guide the optimization of operation ,energy saving and iden- tification of production bottlenecks of units.Using the Aspen Plus process simulation software,researchers es- tablished process simulation for the fractionation system of a 120xl04t/a diesel hydrotreating unit,studied the effect of feed temperature and stripping steam volume of the stripping tower on the contents of H2S and H20 at the bottom of the tower as well as the reboiler furnace of the fractionation tower, and analyzed the effect of raising the feed temperature for the fractionation tower on the gas-liquid phase loads of the tower,gasoline and diesel fuel output and the load of the reboiler.A comprehensive analysis of the results of the above research finds that raising the feed temperature for the stripping tower can strengthen the stripping effect of the tower and reduce the consumption of stripping steam as well as the heat load of the reboiler of the fractionation tow- er.Raising the feed temperature for the fractionation tower can result in more even distribution of gas-liquid phase loads in the tower, in turn improving the operational stability ,increasing the output of gasoline ,reducing the out- put of diesel fuel,raising the economic efficiency of the unit and significantly reducing the load of the reboiler. When the feed temperature of the fraetionation tower increases by 15℃ ,fuel gas savings could reach 209kg/h.