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Indexed by:Journal Papers
Date of Publication:2020-05-01
Journal:PROCESSES
Included Journals:SCIE
Volume:8
Issue:5
Key Words:H-2; CO2; separation; PI membrane; PEO membrane; gasoil hydrogenation
Abstract:A novel process of membrane separation for H-2/CO(2)of shifted syngas coupled with gasoil hydrogenation (NMGH) is proposed. First, a new process, with two-stage CO2-selective and one-stage H-2-selective membranes, was developed to substitute the conventional PSA separation devices to remove CO(2)and purify H(2)in coal gasification refineries to reduce energy consumption and investment costs. Then, the process was coupled with gasoil hydrogenation and the recycled H(2)produced by the hydrogenation reactor could be further purified by the H-2-selective membrane, which increased the H(2)concentration of the hydrogenation reactor inlet by about 11 mol.% compared with the conventional direct recycling process, and the total system pressure was reduced by about 2470 kPa. At the same time, this additional membrane separation and purification prevented the accumulation of CO/CO(2)in the recycled H-2, which ensured the activity of the catalyst in the reactor and the long-term stable operation of the devices. Further, parameters such as compressor power, PI (polyimide)/PEO (polyethylene oxide) membrane area, pressure ratio on both sides of the membrane, and purity of make-up H(2)were optimized by sensitivity analysis. The results showed that, compared with the conventional method, the NMGH process simplified operations, significantly reduced the total investment cost by $17.74 million, and lowered the total annual costs by $1.50 million/year.