Centre for Surface Chemistry and Catalysis, Faculty of Bioengineering Sciences, Katholieke Universiteit Leuven, Kasteelpark Arenberg 23, Post Box 2461, 3001 Leuven, Belgium.
Chem Soc Rev. 2010 Feb;39(2):750-68. doi: 10.1039/b817050a. Epub 2009 Oct 6.
Over the past two decades, membrane processes have gained a lot of attention for the separation of gases. They have been found to be very suitable for wide scale applications owing to their reasonable cost, good selectivity and easily engineered modules. This critical review primarily focuses on the various aspects of membrane processes related to the separation of biogas, more in specific CO(2) and H(2)S removal from CH(4) and H(2) streams. Considering the limitations of inorganic materials for membranes, the present review will only focus on work done with polymeric materials. An overview on the performance of commercial membranes and lab-made membranes highlighting the problems associated with their applications will be given first. The development studies carried out to enhance the performance of membranes for gas separation will be discussed in the subsequent section. This review has been broadly divided into three sections (i) performance of commercial polymeric membranes (ii) performance of lab-made polymeric membranes and (iii) performance of mixed matrix membranes (MMMs) for gas separations. It will include structural modifications at polymer level, polymer blending, as well as synthesis of mixed matrix membranes, for which addition of silane-coupling agents and selection of suitable fillers will receive special attention. Apart from an overview of the different membrane materials, the study will also highlight the effects of different operating conditions that eventually decide the performance and longevity of membrane applications in gas separations. The discussion will be largely restricted to the studies carried out on polyimide (PI), cellulose acetate (CA), polysulfone (PSf) and polydimethyl siloxane (PDMS) membranes, as these membrane materials have been most widely used for commercial applications. Finally, the most important strategies that would ensure new commercial applications will be discussed (156 references).
在过去的二十年中，膜技术在气体分离方面受到了广泛关注。由于其成本合理、选择性好且易于设计模块，因此非常适合大规模应用。本综述主要侧重于与沼气分离相关的膜过程的各个方面，更具体地说，是从 CH₄ 和 H₂ 气流中去除 CO₂ 和 H₂S。考虑到无机材料在膜方面的局限性，本综述仅关注使用聚合物材料所做的工作。首先概述商业膜和实验室制造膜的性能，突出它们在应用方面的问题。随后将讨论为提高气体分离膜性能而进行的开发研究。本综述分为三个部分（i）商业聚合物膜的性能、（ii）实验室制造聚合物膜的性能和（iii）混合基质膜（MMM）在气体分离中的性能。这将包括聚合物水平的结构修饰、聚合物共混以及混合基质膜的合成，其中将特别关注硅烷偶联剂的添加和合适填料的选择。除了对不同膜材料的概述外，该研究还将强调不同操作条件的影响，这些条件最终决定了膜在气体分离中的性能和使用寿命。讨论将主要限于在聚酰亚胺（PI）、醋酸纤维素（CA）、聚砜（PSf）和聚二甲基硅氧烷（PDMS）膜上进行的研究，因为这些膜材料在商业应用中被广泛使用。最后，将讨论确保新商业应用的最重要策略（156 篇参考文献）。
