Biogas is an increasingly attractive renewable resource, envisioned to secure future energy demands and help curb global climate change. To capitalize on this resource, membrane processes and state-of-the-art membranes must efficiently recover methane (CH₄) from biogas by separating carbon dioxide (CO₂). Composite (a.k.a. mixed-matrix) membranes, prepared from common polymers and rationally selected/engineered fillers, are highly promising for this application. This review comprehensively examines filler materials that are capable of enhancing the CO₂/CH₄ separation performance of polymeric membranes. Specifically, we highlight novel synthetic strategies for engineering filler materials to develop high-performance composite membranes. Besides, as the matrix components (polymers) of composite membranes largely dictate the overall gas separation performances, we introduce a new empirical metric, the “Filler Enhancement Index” (F_index), to aid researchers in assessing the effectiveness of the fillers from a big data perspective. The F_index systematically decouples the effect of polymer matrices and critically evaluates both conventional and emerging fillers to map out a future direction for next-generation (bio)gas separation membranes. Beyond biogas separation, this review is of relevance to a broader community with interests in composite membranes for other gas separation processes, as well as water treatment applications.

中文翻译：

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利用填充材料增强沼气分离膜

沼气是一种越来越有吸引力的可再生资源，旨在确保未来的能源需求并帮助遏制全球气候变化。为了利用这种资源，膜工艺和最先进的膜必须通过分离二氧化碳（CO ₂）从沼气中有效地回收甲烷（CH ₄）。由普通聚合物和合理选择/设计的填料制成的复合（又称混合基质）膜在该应用中非常有前途。这篇综述全面地研究了能够增强CO ₂ / CH _4的填充材料聚合物膜的分离性能。具体而言，我们重点介绍了用于工程填料以开发高性能复合膜的新颖合成策略。此外，由于复合膜的基质成分（聚合物）在很大程度上决定了整体气体分离性能，因此，我们引入了一种新的经验指标“填料增强指数”（F_指数），以帮助研究人员从一种填料中评估填料的有效性。大数据角度。该˚F_指数系统地分离聚合物基质的作用，并严格评估常规填料和新兴填料，以勾勒出下一代（生物）气体分离膜的未来发展方向。除沼气分离外，本综述还涉及​​更广泛的社区，这些社区对用于其他气体分离过程以及水处理应用的复合膜感兴趣。