In the pursuit of advanced carbon capture methods, ionic liquid (IL)-based membranes have emerged as promising materials for CO₂ separation due to their high permeation and selectivity. This research focuses on the development of composite membranes with highly CO₂ selective ethanolamine-based ionic liquids and poly(vinyl alcohol) (PVA). ILs and membranes were characterized by water content, FT-IR, ¹H, and ¹³C NMR. The addition of ethanolamine-based ILs and stream humidification promoted an outstanding increase of PVA membranes’ CO₂ permeability and CO₂/CH₄ selectivity of 53× and 36×, respectively. Effects of transmembrane pressure (1.0 to 3.0 barg), temperature (313.15 to 343.15 K), and CO₂:CH₄ ratio (10 to 40%) were studied. Effects of IL’s cations and alkyl chain length (anion) on CO₂ separation performance were studied via the production of PVA membranes with seven ethanolamine-based ILs. CO₂ permeabilities up to 209 barrer and selectivities up to 241 were obtained. The comparison of these membranes with some of the most promising materials in the literature indicates that the ethanolamine-based ILs + PVA membranes have moderate CO₂ permeabilities, associated with outstanding CO₂/CH₄ selectivities.

中文翻译：

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基于乙醇胺离子液体的高选择性CO2/CH4膜

在追求先进的碳捕获方法的过程中，基于离子液体（IL）的膜由于其高渗透性和选择性而成为用于CO ₂分离的有前途的材料。本研究重点开发具有高CO ₂选择性的乙醇胺基离子液体和聚乙烯醇(PVA)的复合膜。 IL 和膜通过水含量、FT-IR、 ¹ H 和¹³ C NMR进行表征。添加基于乙醇胺的离子液体和流加湿促进PVA膜的CO ₂渗透性和CO ₂ /CH ₄选择性显着增加，分别为53×和36×。研究了跨膜压力（1.0 至 3.0 barg）、温度（313.15 至 343.15 K）和 CO ₂ :CH ₄比率（10 至 40%）的影响。通过使用七种基于乙醇胺的离子液体生产PVA膜，研究了离子液体的阳离子和烷基链长度（阴离子）对CO ₂分离性能的影响。获得高达209 barrer的CO ₂渗透性和高达241的选择性。将这些膜与文献中一些最有前途的材料进行比较表明，基于乙醇胺的离子液体+ PVA 膜具有中等的CO ₂渗透性，并具有出色的CO ₂ /CH ₄选择性。