炼化生产计划优化中的分子建模方法

Modeling at Molecular Level in Petrochemical Planning Optimization

为了实现生产方案优化,提高石油炼化加工效益,应用模型开展生产计划优化测算是国内外石化企业的普遍做法。当前国内一些企业采用的传统炼化生产计划优化模型比较宏观,无法精确反映原料组分变化对产品收率和性质的影响,因此有必要在优化模型中引入分子管理理念,实现装置的分子水平建模。文章提出一种在全厂炼化计划优化模型中开展分子建模的方法:首先将二次反应装置构建为多个逻辑装置,其次采用多Delta-base结构描述反应后分子产物随原料组分变化的关系,最后采用分方案物性传递技术将分子组分合成为实际产物以实现产品组分的动态计算。该方法在自主研发的国产炼化计划优化软件平台RIPO上实现。采用某企业数据,建立了包括常减压蒸馏、连续重整和芳烃联合装置分子模型的全厂生产计划优化模型。结果表明,该方法可以实现精细化的分子水平建模和优化,优化结果反映了原料组分及加工方案对目标产品收率和性质的影响,为提高炼化经济效益提供了支持。

This contribution proposes a method to introduce the concept of molecular management into production planning optimization models to achieve molecular-level modeling of petrochemical processes.The conventional production planning optimization models used in China’s some petrochemical enterprises are generally too macroscopic to accurately reflect the impacts of feedstock composition changes on product yields and properties.Therefore,it is necessary to introduce molecular-level modeling in optimization models.Herein,an approach to molecular modeling in overall refinery optimization models was proposed:First,secondary reaction units are constructed as multiple logical devices.Thereafter,multi-delta-base structures are used to describe the correlation between product and feedstock compositions at molecular level.Finally,the scheme-relevant property transfer technology was employed to synthesize molecular feeds into actual products,thus dynamically reflect the molecule compositions in each product feed.This method is implemented on RIPO,the self-developed planning optimization platform.Using data from a certain plant,an overall production planning optimization model involving molecular models of atmospheric distillation units,continuous catalytic reforming units and aromatics complex was established.Results displayed this method can achieve sophisticated molecular-level modeling and optimization.The optimization results revealed the impacts of different crude oil compositions and processing schemes on target product yields and properties,providing support for improving ref ining economics.