炼化企业氢气系统优化

Optimization of Refinery Hydrogen System

随着氢气消耗量的日益增大,氢气成本已经成为炼油企业原料成本中仅次于原油成本的第二位成本要素。炼化企业的氢气系统目前基本是基于经验进行管理,不平衡现象时有发生,管理水平有待提高。针对炼化企业氢气系统存在的问题,建立相应的优化模型,可有效提高氢气利用率,降低氢气系统运行成本。氢气系统优化模型综合考虑了氢气系统的氢阱约束、氢源约束、压缩机约束、流股约束等约束条件,采用非线性数学规划法（MINLP）建模,优化计算得到氢气系统优化方案。优化效果表明,该模型可有效降低氢气系统的运行成本,通过汽柴油加氢装置氢油比优化,每年可获得经济效益23万元;通过制氢装置原料气优化,每年可获得经济效益260万元;通过制氢装置中变反应优化,每年可获得经济效益346万元;通过新建PSA装置回收氢气,每年可获得经济效益915万元。几项合计,每年可实现总效益达1544万元。

As the demand for hydrogen grows,hydrogen cost has become the second most important cost element after crude oil cost in the raw material cost of refineries.Currently the management on refinery hydro-gen system is based on experience,imbalance occurs frequently,and the management level needs to be improved.To solve the problems in refinery hydrogen system,an optimization model was established to effectively increase the hydrogen utilization rate and reduce the operating cost of hydrogen system.This model compre-hensively considers the constraints of hydrogen system including hydrogen sinks,hydrogen sources,compressors and streams,and uses mixed integer nonlinear programming（MINLP） to optimize the hydrogen system.The re-sults show that this model can effectively reduce the operating cost of hydrogen system.Through the optimiza-tion of the hydrogen to oil ratio in gasoline and diesel hydrogenation units,an annual economic benefit of230 thousand yuan can be obtained; through the optimization of the feed gas to hydrogen plant,an annual economic benefit of 2.6 million yuan can be obtained;through the optimization of the medium temperature shift reaction in hydrogen plant,an annual economic benefit of 3.46 million yuan can be obtained; and through the installation of PSA unit for hydrogen recovery,an annual economic benefit of 9.15 million yuan can be obtained.In total,an annual profit of 15.44 million yuan can be achieved.