Diffusion Kinetics of Ethane, Ethylene, and their Binary Mixtures in Ethane-Selective Adsorbents

Abstract

Sorption kinetics of single component and binary mixtures of ethane and ethylene in powder and pellet samples of paraffin-selective adsorbents Ni(bdc)(ted) 0.5 and ZIF-7 were investigated by zero-length column (ZLC) technique for the purpose of olefin/paraffin separation. The intracrystalline diffusivities were determined at 25 °C and the results were compared in order to investigate the effects of coadsorption for binary gas mixtures and also diffusion in pelletized adsorbents. The diffusion time constants measured for ethane and ethylene through both ZIF-7 and Ni(bdc)(ted)0.5 in powder and pellet forms were similar and found to be in the ranges of 2.68-3.35 x 10-3 s-1 and 1.23-4.07 x 10-3 s-1, respectively, for single component and binary mixtures. Furthermore, diffusion of ethylene for both single component and binary mixture trials revealed the presence of surface resistance due to strong interactions between the C—C double bond and the external crystalline surface of the adsorbents. The findings of this study provide novel kinetic characterizations on paraffin-selective adsorbents for the separation of ethane and ethylene.

Department(s)

Chemical and Biochemical Engineering

Research Center/Lab(s)

Center for Research in Energy and Environment (CREE)

Keywords and Phrases

Diffusion time constant; Ethane/ethylene separation; Intracrystalline diffusivity; Ni(bdc)(ted)0.5; ZIF-7; ZLC technique

International Standard Serial Number (ISSN)

1383-5866

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2020 Elsevier B.V., All rights reserved.

Publication Date

01 Jan 2020

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