Erdős Máté, Geerdink Daan F, Martin-Calvo Ana, Pidko Evgeny A, van den Broeke Leo J P, Calero Sofia, Vlugt Thijs J H, Moultos Othonas A
Engineering Thermodynamics, Process & Energy Department, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Leeghwaterstraat 39, 2628CB Delft, The Netherlands.
Department of Physical, Chemical, and Natural Systems, Universidad Pablo de Olavide, Ctra. Utrera km, 1, ES-41013 Seville, Spain.
ACS Appl Mater Interfaces. 2021 Feb 24;13(7):8383-8394. doi: 10.1021/acsami.0c20892. Epub 2021 Feb 10.
According to the ISO 14687-2:2019 standard, the water content of H fuel for transportation and stationary applications should not exceed 5 ppm (molar). To achieve this water content, zeolites can be used as a selective adsorbent for water. In this work, a computational screening study is carried out for the first time to identify potential zeolite frameworks for the drying of high-pressure H gas using Monte Carlo (MC) simulations. We show that the Si/Al ratio and adsorption selectivity have a negative correlation. 218 zeolites available in the database of the International Zeolite Association are considered in the screening. We computed the adsorption selectivity of each zeolite for water from the high-pressure H gas having water content relevant to vehicular applications and near saturation. It is shown that due to the formation of water clusters, the water content in the H gas has a significant effect on the selectivity of zeolites with a helium void fraction larger than 0.1. Under each operating condition, five most promising zeolites are identified based on the adsorption selectivity, the pore limiting diameter, and the volume of H gas that can be dried by 1 dm of zeolite. It is shown that at 12.3 ppm (molar) water content, structures with helium void fractions smaller than 0.07 are preferred. The structures identified for 478 ppm (molar) water content have helium void fractions larger than 0.26. The proposed zeolites can be used to dry 400-8000 times their own volume of H gas depending on the operating conditions. Our findings strongly indicate that zeolites are potential candidates for the drying of high-pressure H gas.
根据ISO 14687-2:2019标准，用于运输和固定式应用的H燃料的水含量不应超过5 ppm（摩尔）。为达到此水含量，可使用沸石作为水的选择性吸附剂。在这项工作中，首次开展了一项计算筛选研究，以使用蒙特卡洛（MC）模拟来识别用于干燥高压H气体的潜在沸石骨架。我们表明，硅铝比与吸附选择性呈负相关。筛选过程中考虑了国际沸石协会数据库中的218种沸石。我们计算了每种沸石对来自具有与车辆应用相关且接近饱和水含量的高压H气体中水的吸附选择性。结果表明，由于水团簇的形成，H气体中的水含量对氦孔隙率大于0.1的沸石的选择性有显著影响。在每种操作条件下，根据吸附选择性、孔隙极限直径以及1 dm沸石可干燥的H气体体积，确定了五种最有前景的沸石。结果表明，在水含量为12.3 ppm（摩尔）时，氦孔隙率小于0.07的结构更受青睐。为水含量478 ppm（摩尔）确定的结构的氦孔隙率大于0.26。根据操作条件，所提出的沸石可用于干燥其自身体积400 - 8000倍的H气体。我们的研究结果有力地表明，沸石是干燥高压H气体的潜在候选材料。
