Xiang Jin , Sihao Wang , Yongsheng Zhao , Lang Liu , Xuechao Gao , Xuehong Gu
{"title":"Analysis of the gas transport resistance of CO2 and CH4 through ultra-thin DD3R zeolite membrane","authors":"Xiang Jin , Sihao Wang , Yongsheng Zhao , Lang Liu , Xuechao Gao , Xuehong Gu","doi":"10.1016/j.memsci.2024.122929","DOIUrl":null,"url":null,"abstract":"<div><p>Ultra-thin DD3R zeolite membranes exhibit excellent separation properties for CO<sub>2</sub> capture from natural gas, as well as the lower transmembrane resistance. However, the interfacial transport of permeation gas in such systems may dominate the whole separation process. In this work, we employed external force non-equilibrium molecular dynamic (EF-NEMD) simulation to predict the single-component permeabilities of CO<sub>2</sub> and CH<sub>4</sub> through a defect-free DD3R zeolite membrane at different pressured drops. By explicitly including the gas transport from bulk phase to zeolitic channels, the predicted results of EF-NEMD simulation showed good agreements with the reported experimental data. The contribution of interfacial resistance over the total transport resistance (<em>R</em><sub>inter</sub>/<em>R</em><sub>total</sub>) was further evaluated for the membranes with different thicknesses under temperatures between 273 K and 373 K. The results revealed a decrease in <em>R</em><sub>inter</sub>/<em>R</em><sub>total</sub> with increasing membrane thickness, leading to a reduction in CO<sub>2</sub>/CH<sub>4</sub> selectivity, and the critical thickness (<em>R</em><sub>inter</sub>/<em>R</em><sub>total</sub> < 0.01) was determined to be approximately 300 nm at pressure of 1.0 MPa and temperature of 298 K. Similarly, the <em>R</em><sub>inter</sub>/<em>R</em><sub>total</sub> decreased with increasing temperature due to the augmentation in molecule kinetic energy. Furthermore, it was confirmed that the gas adsorption effect could expand the effective size of eight membered ring (8-MR) channels in DD3R zeolite membrane, thereby decreasing the CO<sub>2</sub>/CH<sub>4</sub> selectivity, despite higher permeation fluxes. The above discoveries essentially benefit the design of the ultra-thin DD3R zeolite membrane through an understanding of CO<sub>2</sub> and CH<sub>4</sub> transport behaviors.</p></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":null,"pages":null},"PeriodicalIF":8.4000,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Membrane Science","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0376738824005234","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Ultra-thin DD3R zeolite membranes exhibit excellent separation properties for CO2 capture from natural gas, as well as the lower transmembrane resistance. However, the interfacial transport of permeation gas in such systems may dominate the whole separation process. In this work, we employed external force non-equilibrium molecular dynamic (EF-NEMD) simulation to predict the single-component permeabilities of CO2 and CH4 through a defect-free DD3R zeolite membrane at different pressured drops. By explicitly including the gas transport from bulk phase to zeolitic channels, the predicted results of EF-NEMD simulation showed good agreements with the reported experimental data. The contribution of interfacial resistance over the total transport resistance (Rinter/Rtotal) was further evaluated for the membranes with different thicknesses under temperatures between 273 K and 373 K. The results revealed a decrease in Rinter/Rtotal with increasing membrane thickness, leading to a reduction in CO2/CH4 selectivity, and the critical thickness (Rinter/Rtotal < 0.01) was determined to be approximately 300 nm at pressure of 1.0 MPa and temperature of 298 K. Similarly, the Rinter/Rtotal decreased with increasing temperature due to the augmentation in molecule kinetic energy. Furthermore, it was confirmed that the gas adsorption effect could expand the effective size of eight membered ring (8-MR) channels in DD3R zeolite membrane, thereby decreasing the CO2/CH4 selectivity, despite higher permeation fluxes. The above discoveries essentially benefit the design of the ultra-thin DD3R zeolite membrane through an understanding of CO2 and CH4 transport behaviors.
期刊介绍:
The Journal of Membrane Science is a publication that focuses on membrane systems and is aimed at academic and industrial chemists, chemical engineers, materials scientists, and membranologists. It publishes original research and reviews on various aspects of membrane transport, membrane formation/structure, fouling, module/process design, and processes/applications. The journal primarily focuses on the structure, function, and performance of non-biological membranes but also includes papers that relate to biological membranes. The Journal of Membrane Science publishes Full Text Papers, State-of-the-Art Reviews, Letters to the Editor, and Perspectives.