炼油厂富氢气体回收装置投用对氢网运行的影响

Effect of Hydrogen-rich Gas Recovery Unit on Operation of Hydrogen System in Refinery

随着对燃油清洁性要求的不断提高,炼油厂对氢气的需求不断增加,含氢尾气量随之增加,回收炼油厂尾气中的氢气是降低炼油厂制氢成本的重要措施之一。通过对大连石化公司氢网运行现状、12套加氢装置用氢需求和产氢装置情况,氢网压力等级及氢气平衡,膜分离气体分离的工艺原理,以及该公司新建的变压吸附+膜分离耦合气体分离工艺及具体的工艺流程进行介绍,对富氢气体回收装置投用和标定情况,以及投用后对氢网的影响进行了分析。富氢气体回收装置投用后,燃料气中的氢气含量从30%~90%大幅下降到15%~30%,有利于加热炉稳定运行。PSA解析气由进入燃料气或者作为制氢原料改为进入富氢回收装置,提高了氢气回收率。停用了一套制氢装置,每年可节约液化气13×10^4t,大幅降低了制氢成本。改善了PSA单元的操作条件,延长了吸附剂使用寿命。对富氢气体回收装置投用后出现的氢气产品中的CO2含量升高、富氢气体回收装置适合的进料类型、原料切液等问题进行了探讨。

With stricter requirements on the cleanliness of fuel oil,the demand for hydrogen in refineries is increasing,and the amount of hydrogen-containing tail gas is increasing.The recovery of hydrogen from tail gas in refineries is one of the important measures to reduce the hydrogen production cost of refineries.This paper introduces the operation status of hydrogen network at PetroChina Dalian Petrochemical Company,the hydrogen demand of 12 hydrotreating units and the composition of hydrogen production units,the pressure grade of hydrogen network and the hydrogen balance,the principle of gas separation process in membrane separation system and the process and instrument diagram of the new process of membrane gas separation system combined with PSA,and analyzes the use and test run of hydrogen-rich gas recovery unit and its effect on hydrogen system.After the hydrogen-rich gas recovery unit was put into use,the hydrogen content of fuel gas remarkably dropped from 30~90%to 15~30%,which is favorable for the stable operation of furnace.PSA parsing gas entered hydrogen-rich gas recovery unit instead of entering fuel gas or being used as hy-drogen production feedstock,improving the recovery rate of hydrogen.A hydrogen plant was shut down,saving 130000 tons of liquefied gas per year and greatly reducing the hydrogen production cost.The operating conditions of PSA unit were improved,and the service life of adsorbent was extended.The problems emerged after the use of hydrogen-rich gas recovery unit,such as the higher CO2 content of hydrogen product and the suitable feed type for hydrogen-rich gas recovery unit are also discussed.