Fabrication of an Asymmetric 4,4鈥?Oxydiphthalic Anhydride鈥?,4,6-Trimethyl-1,3-phenylenediamine/2,6-Diaminotoluene Copolyimide Hollow Fiber Membrane and Its Performance for CO2 Separation

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• 作者：Xingming Jie ; Cuijia Duan ; Lina Wang ; Can Jiang ; Hong Zheng ; Jianhui Liu ; Dandan Liu ; Yiming Cao ; Quan Yuan
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：March 19, 2014
• 年：2014
• 卷：53
• 期：11
• 页码：4442-4452
• 全文大小：566K
• 年卷期：v.53,no.11(March 19, 2014)
• ISSN：1520-5045

文摘

In this work, a novel copolyimide (CPI) of 4,4鈥?oxydiphthalic anhydride鈥?,4,6-trimethyl-1,3-phenylenediamine/2,6-diaminotoluene was synthesized and its defect-free asymmetric hollow fiber membrane (HFM) was fabricated successfully through a dry鈥搘et spinning method with a 33.3 wt % CPI concentration in dope. When tested at 25.0 掳C and 0.30 MPa, its CO₂ permeance was 39 GPU with ideal selectivities of 44.3 over N₂ and 47.0 over CH₄. A plasticization test proved that this CPI HFM could be reliably operated with CO₂ partial pressure no higher than 2.25 MPa. The highest testing pressure in this work was 6.6 MPa with a gas mixture of CO₂/N₂ (50%/50%), and the fibers did not show any mechanical collapse. Continued tests with the same gas mixture showed that CO₂ percentage in permeate could be enriched to 93.3鈥?5.1% by a test pressure increase from 0.5 to 4.5 MPa at room temperature. When tested with a feed gas of CO₂/CH₄ (10%/90%) mixture, CO₂ percentage in permeate could reach 59.9鈥?2.7% under similar conditions. An operation temperature increase obviously facilitated gas mixture permeation while the separation performance degraded. At the end, influence of released gas flow rate was investigated with both gas mixtures. It was clearly seen that release flow rate increase was beneficial for gas permeation in HFM, and as a result, higher CO₂ concentration in permeate could be seen, while at the same time product quality of released gas was inevitably changed in an undesired way. In conclusion, the prepared CPI HFM shows promising application potential in the field of CO₂ separation and capture from natural gas.