膜分离技术在炼油厂氢气回收中的应用研究

Application of membrane separation technologyin hydrogen recovery in refinery

为解决某炼油厂氢气利用率低的问题,通过分析氢气管网平衡的实际情况提出改进措施:新增一条重整副产氢气直供柴油改质装置管线,并新增一条管线将重整产氢与氢气管网中氢气混合后送入加氢裂化装置;新建膜分离装置,回收柴油改质低分气、加氢裂化低分气、加氢裂化干气、催化裂化干气、气柜气中的氢气。优化后氢气回收率达到88%以上,氢气利用率由原来的81.96%增大至95.15%。同时考察了膜分离单元M-102进膜压力、膜面积的改变对氢气回收率、纯度以及经济效益的影响。结果表明:氢气回收率和纯度都随着进膜压力和膜面积的增大而提高,当M-102的进膜压力为1.34 MPa时,最优膜面积为3200 m^(2),每年可回收8.5744×10^(7) m^(3)氢气,年经济效益为4612万元。

In order to solve the problem of low utilization rate of hydrogen in a refinery,the improvement measures are put forward by analyzing the actual situation of hydrogen pipe network balance as follows:adding a new pipeline for direct supply of reforming by-product hydrogen to diesel upgrading unit,and adding a new pipeline for mixing reforming hydrogen with hydrogen in hydrogen pipe network and entering hydrocracking unit;building a new membrane separation unit to recover hydrogen of gas from low pressure separator of diesel upgrading unit,gas from low pressure separator of hydrocracking unit,hydrocracking dry gas,catalytic dry gas and gasholder gas.After optimization,the recovery rate of hydrogen is over 88%,and the utilization rate of hydrogen increases from 81.96%to 95.15%.The results show that the recovery rate and purity of hydrogen increase with the increase of membrane inlet pressure and membrane area.When the inlet pressure of M-102 is 1.34 MPa,the optimal membrane area is 3,200 square meters,85.744 million cubic meters hydrogen can be recovered every year,and the annual economic benefit is 46.12 million yuan.