Abstract Membranes can potentially offer low-cost CO2 capture from post-combustion flue gas. However, the low partial pressure of CO2 in flue gases can inhibit their effectiveness unless methods are employed to increase their partial pressure. Selective-Exhaust Gas Recirculation (S-EGR) has recently received considerable attention. In this study, the performance of a dense polydimethylsiloxane (PDMS) membrane for the separation of CO2/N2 binary model mixtures for S-EGR application was investigated using a bench-scale experimental rig. Measurements at different pressures, at different feeding concentrations and with nitrogen as sweep gas revealed an average carbon dioxide permeability of 2943 ± 4.1%RSD Barrer. The bench-scale membrane module showed high potential to separate binary mixtures of N2 and CO2 containing 5–20% CO2. The permeability was slightly affected by feed pressures ranging from 1 to 2.4 bar. Furthermore, the separation selectivity for a CO2/N2 mixture of 10%/90% (by volume) reached a maximum of 10.55 at 1.8 bar. Based on the results from the bench-scale experiments, a pilot-scale PDMS membrane module was tested for the first time using a real flue gas mixture taken from the combustion of natural gas. Results from the pilot-scale experiments confirmed the potential of the PDMS membrane system to be used in an S-EGR configuration for capture of CO2.

中文翻译：

---

使用膜技术进行 CO 2 捕集的选择性废气再循环

摘要 膜可以潜在地从燃烧后的烟道气中捕获低成本的 CO2。然而，除非采用增加其分压的方法，否则烟道气中 CO2 的低分压会抑制其有效性。选择性废气再循环 (S-EGR) 最近受到了相当大的关注。在这项研究中，使用实验室规模的实验装置研究了用于分离 S-EGR 应用的 CO2/N2 二元模型混合物的致密聚二甲基硅氧烷 (PDMS) 膜的性能。在不同压力、不同进料浓度和氮气作为吹扫气下进行的测量显示平均二氧化碳渗透率为 2943 ± 4.1% RSD Barrer。实验室规模的膜组件在分离含有 5-20% CO2 的 N2 和 CO2 的二元混合物方面表现出很高的潜力。渗透率受 1 到 2.4 bar 的进料压力的影响很小。此外，10%/90%（体积）的 CO2/N2 混合物的分离选择性在 1.8 bar 下达到了 10.55 的最大值。根据实验室规模实验的结果，首次使用取自天然气燃烧的真实烟气混合物对中试规模的 PDMS 膜组件进行了测试。中试规模实验的结果证实了 PDMS 膜系统在 S-EGR 配置中用于捕获 CO2 的潜力。首次使用取自天然气燃烧的真实烟气混合物测试了中试规模的 PDMS 膜组件。中试规模实验的结果证实了 PDMS 膜系统在 S-EGR 配置中用于捕获 CO2 的潜力。首次使用取自天然气燃烧的真实烟气混合物测试了中试规模的 PDMS 膜组件。中试规模实验的结果证实了 PDMS 膜系统在 S-EGR 配置中用于捕获 CO2 的潜力。