碳分子篩薄膜氣體分離性能調控及老化抑制之研究

氧所造成之化學老化問題是碳分子篩膜商業化應用最大的阻礙。本研究使用商業化Kapton作為先驅物薄膜，在800℃的氬氣環境下碳化後，接著在空氣環境進行後處理，期望藉由氧化與預吸附調控碳分子篩薄膜的孔洞結構並抑制化學老化作用。不同後處理溫度及不同空氣暴露時間對碳分子篩薄膜氣體透過效能的影響在本研究中被詳細地討論以決定後處理的最佳條件。XRD分析顯示碳分子篩薄膜經後處理後其層間距變大。BET結果顯示後處理使得孔洞整體往大尺寸偏移。PALS測試結果亦說明後處理使得孔洞尺寸變大。氣體等溫吸附結果顯示，後處理的碳膜具有較低吸附量，代表後處理的碳膜具有較少數量的化學吸附活性位置，因此老化程度較低。氣體透過測試結果可發現，400℃空氣處理5個小時具有最高二氧化碳透過量，且相較於未處理的碳膜擁有較低的老化程度。經過四周老化後，後處理碳膜的氣體透過量仍然高於未處理的碳膜一倍，本研究利用後處理可有效調控碳分子篩薄膜的孔洞結構並降低化學老化程度。

關鍵字

碳分子篩薄膜；二氧化碳分離；化學老化；空氣後處理

並列摘要

Carbon molecular sieve membranes (CMSMs) were regarded as one of the promising membrane for gas separation because of its outstanding separation performance. The industrial application of CMSMs was limited by its chemical aging. In this study, the degree of chemical aging was decreased using air post-treatment. It was fabricated through pyrolyzing Kapton at 800°C followed by an air post-treatment at different temperature and exposure time. XRD analysis confirmed that the d-spacing of CMSMs was increased after air post-treatment. BET analysis demonstrated that post-treated membranes have higher BET and Langmuir surface area than that of untreated CMSMs. PALS analysis indicated that pore diameter was increased after air post-treatment. Gas sorption isotherm showed that the decrease of adsorption capacities of post-treated CMSMs was due to the decrease of active sites, leading to lower degree of aging. Gas separation test revealed that air post-treatment may enhance the gas permeability and reduce the degree of aging of CMSMs. CMSMs was post-treated at 400℃ for 5h and after 1 month aging, it had higher CO2 permeability and considerable CO2/N2 selectivity (P=56barrer, α=147) than the untreated CMSMs (P=28barrer, α=186).

並列關鍵字

CMSMs ； Carbon dioxide separation ； Chemical aging ； Air post treatment

參考文獻

[1] C.E. Powell, G.G. Qiao, Polymeric CO2/N2 gas separation membranes for the capture of carbon dioxide from power plant flue gases, J. Membr. Sci., 279 (2006) 1-49.

[2] D.Y.C. Leung, G. Caramanna, M.M. Maroto-Valer, An overview of current status of carbon dioxide capture and storage technologies, Renewable Sustainable Energy Rev., 39 (2014) 426-443.

[3] M. Mulder, Basic principles of membrane technology, Springer, Netherlands, 1996.

[4] A.F. Ismail, K.C. Khulbe, T. Matsuura, Gas separation membranes : polymeric and inorganic, Springer, Switzerland, 2015.

[5] L.M. Robeson, Correlation of separation factor versus permeability for polymeric membranes, J. Membr. Sci., 62 (1991) 165-185.

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碳分子篩薄膜氣體分離性能調控及老化抑制之研究

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