异构化装置排放气回收氢气可行性分析

Feasibility analysis of hydrogen recovery from exhaust gas of isomerization unit

中国石化塔河炼化有限责任公司300 kt/a临氢异构化装置采用氢气一次通过流程,反应尾气富含70%左右的氢气经碱洗塔后排入燃料气系统,造成大量氢源浪费。为此提出三种氢气回收可行性方案。方案1:尾气进1号加氢膜分离装置氢气提纯装置后并入全厂氢气管网;方案2:尾气进2号制氢装置作为制氢的原料之一,经工艺流程后产出氢纯度99.99%、压力2.2 MPa的氢气并入氢气管网;方案3:尾气进连续重整装置增压机入口经升压后并入氢气管网。综合可操作性和经济效益,得出最佳可实施性方案为方案2。经测算,采用方案2回收氢气每年最多可增加效益453.6万元,可为氢源的回收操作提供参考。

SINOPEC Tahe Petrochemical Co., Ltd. 300 kt/a hydro-isomerization unit adopts the process of hydrogen passing through at one time. The reaction tail gas is rich in hydrogen(about 70%), which is discharged into the fuel gas system after alkali washing tower, resulting in a large amount of waste of hydrogen source. Three feasible schemes for hydrogen recovery are proposed. Scheme 1: the tail gas enters the hydrogen purification unit of No.1 hydrogenation membrane separation unit and then is connected to the hydrogen pipe network of the whole plant. Scheme 2: the tail gas enters the No.2 hydrogen production unit as one of the feedstock for hydrogen production, the hydrogen with purity of 99.99% and pressure of 2.2 MPa is produced and put into the hydrogen pipe network. Scheme 3: the tail gas enters into the inlet of the booster of the continuous reforming unit and is connected to the hydrogen pipe network after boosting. Considering the operability and economic benefits, the best feasible scheme is scheme 2. It is estimated that the maximum benefit can be increased by 4.536 million yuan per year by using scheme 2 to recover hydrogen. It can provide a reference for the recovery of hydrogen source.