Bünger Lucas, van Gestel Tim, Kurtz Tim, Garbev Krassimir, Stemmermann Peter, Meulenberg Wilhelm A, Guillon Olivier, Stapf Dieter
Institute for Technical Chemistry, Karlsruhe Institute of Technology, 76344 Karlsruhe, Germany.
Institute of Energy Materials and Devices-IMD-2, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
Membranes (Basel). 2025 Mar 5;15(3):83. doi: 10.3390/membranes15030083.
For industrial CO utilization, the supply of concentrated CO within a continuous, high-volume stream at high temperatures remains a substantial requirement. Membrane processes offer a simple and efficient method to provide CO in this form. While several organo-silica-based membranes have been developed for CO/N separation under these conditions, there is no standardized framework guiding comparability and optimization. Therefore, we present these membranes in a Robeson-like plot across various temperatures. Utilizing a standard 1,2-bis(triethoxysilyl)-ethane (BTESE) precursor and a simplified sol-gel method, we prepared a microporous membrane layer and characterized it for an exemplary comparison. This characterization includes key parameters for mixed-gas applications: (1) temperature-dependent single- and mixed-gas permeances to observe interactions, (2) the impact of the driving forces in mixtures (vacuum and concentration) to distinguish between permselectivity and the separation factor clearly, and (3) influence of the support structure to enable permeability calculations at elevated temperatures. Furthermore, a quick interpretation method for assessing the membrane's microstructure is presented. A qualitative microstructure assessment can be achieved by analyzing the temperature dependencies of the three major diffusion mechanisms that simultaneously occur-Knudsen, surface, and activated diffusion.
对于工业上一氧化碳的利用，在高温下以连续、大量的气流形式供应高浓度一氧化碳仍然是一项重大需求。膜过程提供了一种以这种形式提供一氧化碳的简单而有效的方法。虽然已经开发了几种基于有机硅的膜用于在这些条件下进行一氧化碳/氮气分离，但尚无指导可比性和优化的标准化框架。因此，我们在不同温度下以类似罗布森图的形式展示这些膜。利用标准的1,2-双（三乙氧基硅基）乙烷（BTESE）前驱体和简化的溶胶-凝胶法，我们制备了一个微孔膜层并对其进行表征以进行示例比较。这种表征包括混合气体应用的关键参数：（1）温度相关的单气体和混合气体渗透率以观察相互作用，（2）混合物中驱动力（真空和浓度）的影响以清楚地区分渗透选择性和分离因子，以及（3）支撑结构的影响以实现高温下的渗透率计算。此外，还提出了一种评估膜微观结构的快速解释方法。通过分析同时发生的三种主要扩散机制——努森扩散、表面扩散和活化扩散——的温度依赖性，可以实现微观结构的定性评估。
