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Mass transfer through PDMS/zeolite 4A MMMs for hydrogen separation: Molecular dynamics and grand canonical Monte Carlo simulations

Riasat Harami, H ; Sharif University of Technology | 2019

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  1. Type of Document: Article
  2. DOI: 10.1016/j.icheatmasstransfer.2019.05.005
  3. Publisher: Elsevier Ltd , 2019
  4. Abstract:
  5. In industry, utilizing membrane separation technology to purify natural gas streams is of remarkable significance. Molecular Simulation was used in the current article to study the structural and gas separation properties of polydimethylsiloxane (PDMS)/zeolite 4A Mixed Matrix Membranes (MMMs). To explore the optimal performance of MMMs, several structural analyses, namely Fractional Free Volume (FFV), Radial Distribution Function (RDF), X-Ray Diffraction (XRD) and also Glass Transition Temperature (Tg) as one of the most important properties of membranes have been evaluated. Also, the solubilities and diffusivities of periodic cells were respectively measured using MSD and adsorption isotherms. In the present work, the resultant MD simulations of MMMs prove that the doped PDMS with zeolite 4A has a great potential of being employed compared to simple membrane because the nanomaterials increase the pathways for the penetrant molecules. Accordingly, enhancing the contents of the zeolite 4A in PDMS matrix is the underlying reason to improve the H2 purification. We further assessed our methodology, by comparison, the outcomes of simulations with experimental data in the literature that they were pretty close to each other. Our main finding is that the increase in the zeolite 4A content from 0 to 50 wt% boosts the permeability in the membrane concerning H2. On the other side, the 50 wt% loaded membrane indicated the highest H2/CH4 selectivity; which could be related to the increasing FFV, because those of for constructed membranes soared gradually with particle loading. The glass transition temperature increases from 149 to 157.5 K which signifies the matrix is getting more amorphous. © 2019 Elsevier Ltd
  6. Keywords:
  7. Gas separation ; Grand canonical Monte Carlo (GCMC) ; Molecular dynamics (MD), molecular simulation ; PDMS/zeolite 4A MMMs ; Distribution functions ; Glass ; Glass transition ; Hydrogen ; Intelligent systems ; Mass transfer ; Membrane technology ; Microchannels ; Molecular dynamics ; Molecular structure ; Monte Carlo methods ; Polydimethylsiloxane ; Silicones ; Temperature ; Zeolites ; Gas separations ; Grand canonical Monte carlo ; Grand canonical Monte Carlo simulation ; Membrane separation technology ; Mixed matrix membranes ; Molecular simulations ; Polydimethylsiloxane PDMS ; Radial distribution functions ; Gas permeable membranes
  8. Source: International Communications in Heat and Mass Transfer ; Volume 108 , 2019 ; 07351933 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0735193319301113