基于分子集总的催化裂化柴油轻重切割优化研究

Optimization of LCO distillation cutting based on molecular lump

针对某炼油厂催化裂化柴油(催柴)加工氢耗高的问题,基于分子集总进行加氢反应及精馏切割的研究。通过Aspen HYSYS软件对现场实际工况进行建模,利用分子集总进行催柴的原料表征,基于分子集总分析催柴精馏切割后对不同分子的提浓作用,并通过加氢反应建模评价分子提浓后氢耗、产品性质及下游综合利用的变化,从而定量计算轻、重催柴分炼后的产品性质及整体效益。结合现场工况,将76.5 t/h的催柴以290~310℃为切割点进行精馏切割,其中轻催柴送至加氢精制装置,重催柴送至加氢改质装置,从而可提高催化柴油加氢过程的选择性,有效避免单环芳烃、环烷烃分子过度饱和、开环。通过建模分析及优化计算,催柴加氢过程纯氢耗量降低2 380 m3/h,折合全厂催柴加工氢耗降低9.9%。结合轻重切割能耗等成本,方案综合效益约为1 574万元/a。

A study on hydrogenation reaction and distillation cutting based on molecular lump is conducted to reduce hydrogen consumption of LCO processing in a refinery.Modeling the actual working conditions on site data using Aspen HYSYS software,characterizing the LCO feedstock using molecular lump,and analyzing the concentration effect of LCO after distillation cutting on different molecules based on molecular lump,and evaluating the changes in hydrogen consumption,product properties,and downstream comprehensive utilization after molecular concentration by modeling the hydrogenation reaction,in order to quantitatively calculate the product properties and overall benefits after light and heavy LCO refining.Combined with the site conditions,distillation cutting 76.5 t/h LCO at 290~310℃,where the light LCO is sent to the hydrofining unit and the heavy LCO is sent to the hydroupgrading unit,which can improve the selectivity of LCO hydrogenation process and effectively avoid the over saturation and ring opening of monocyclic aromatic hydrocarbons and cycloalkane.Through modeling analysis and optimization calculation,the pure hydrogen consumption in the LCO hydrogenation process is reduced by 2,380 m 3/h,which is equivalent to a 9.9%reduction in hydrogen consumption of the entire factory’s LCO processing.Combined with distillation cutting energy consumption and other costs,the annual comprehensive benefit of the plan is 15.74 million yuan.