Majid-Nateri Behnam, Abedini Reza, Amiri Alireza
Enhanced Oil Recovery and Gas Processing Research Lab, Faculty of Chemical Engineering, Babol Noshirvani University of Technology, Babol, Iran.
Sci Rep. 2025 Apr 25;15(1):14418. doi: 10.1038/s41598-025-95237-x.
Carbon dioxide (CO) generally exists as the main impurity in natural gas, whose main component is methane. The presence of CO reduces the energy content of natural gas and also causes the corrosion of pipelines. To prevent such problems, natural gas must contain a small concentration of CO (less than 2% by weight). Membrane technology is an attractive separation method that has been widely studied due to its advantages such as high efficiency, low operating costs, and low energy requirements. However, in the last decade, Mixed Matrix Membranes (MMMs) have attracted the attention of many researchers due to their suitable capabilities in separating polar from non-polar gases. In this research, a new MMMs was obtained by adding imidazole zeolite nanoparticle (ZIF-8) to the poly methyl pentene (PMP) polymer matrix. The polymer part of this membrane can provide high permeability and suitable mechanical and thermal stability. In addition, ZIF-8 particles enhance CO separation by offering high CO adsorption capacity and molecular sieving, improving selectivity. The gas permeability test was performed on pure and mixed matrix membranes at 30 ℃ and pressures of 2, 6 and 10 bar. In addition, the fabricated membranes were evaluated by FESEM, FTIR-ATR, BET, DMA and TGA tests. The results indicated that in the MMMs containing 30 wt% of nanoparticles in the polymer, the permeability of CO gas improved by more than 180% and reached about 278.95 barrer, compared to the pure polymer membrane at a pressure of 10 bar. Moreover, the selectivity of CO₂/CH₄ and CO₂/H₂ increased by 142% and 155%, respectively, primarily due to the preferential sorption of CO₂ over H₂ and CH₄ facilitated by ZIF-8 particles.
二氧化碳（CO₂）通常作为天然气中的主要杂质存在，天然气的主要成分是甲烷。CO₂的存在降低了天然气的能量含量，还会导致管道腐蚀。为防止此类问题，天然气中必须含有低浓度的CO₂（重量比小于2%）。膜技术是一种具有吸引力的分离方法，因其具有高效、低运营成本和低能量需求等优点而受到广泛研究。然而，在过去十年中，混合基质膜（MMMs）因其在分离极性气体和非极性气体方面的合适能力而吸引了许多研究人员的关注。在本研究中，通过将咪唑沸石纳米颗粒（ZIF-8）添加到聚甲基戊烯（PMP）聚合物基质中获得了一种新型MMMs。该膜的聚合物部分可提供高渗透性以及合适的机械和热稳定性。此外，ZIF-8颗粒通过提供高CO₂吸附容量和分子筛作用来增强CO₂分离，从而提高选择性。在30℃以及2、6和10巴的压力下对纯膜和混合基质膜进行了气体渗透性测试。此外，通过场发射扫描电子显微镜（FESEM）、傅里叶变换红外衰减全反射光谱（FTIR-ATR）、比表面积分析仪（BET）、动态热机械分析（DMA）和热重分析（TGA）测试对制备的膜进行了评估。结果表明，在聚合物中含有30 wt%纳米颗粒的MMMs中，在10巴压力下，与纯聚合物膜相比，CO₂气体的渗透率提高了180%以上，达到约278.95巴每尔。此外，CO₂/CH₄和CO₂/H₂的选择性分别提高了142%和155%，这主要是由于ZIF-8颗粒促进了CO₂相对于H₂和CH₄的优先吸附。
