Premium
Carbon molecular sieve membranes for natural gas purification: Role of surface flow
Author(s) -
Khan Shaihroz,
Wang Kean,
Feng Xianshe,
Elkamel Ali
Publication year - 2020
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.23661
Subject(s) - permeation , membrane , selectivity , molecular sieve , permeability (electromagnetism) , chemistry , pyrolysis , chromatography , chemical engineering , nitrogen , gas separation , analytical chemistry (journal) , organic chemistry , adsorption , catalysis , biochemistry , engineering
Carbon molecular sieve membranes (CMSM) were prepared from the pyrolysis of polyimide films within a temperature range of 600°C‐800°C under nitrogen stream. The membrane samples were characterized and tested for the permeation of He, CH 4 , CO 2 , and N 2 at different pressures and temperatures, respectively. The CMSM700 membrane (pyrolyzed at 700°C) showed an ideal selectivity of ~ 11 for N 2 /CH 4 with a permeability of 2.18 × 10 −15 mol · m/m 2 · s · Pa for N 2 . The separation mechanism for the N 2 /CH 4 pair was shown to be largely molecular sieving rather than surface flow. The membrane showed an ideal selectivity of ~ 500 for the CO 2 /CH 4 pair with a CO 2 permeability of 9.72 × 10 −14 mol · m/m 2 · s · Pa. The permeability of He was lower than that of CO 2 , suggesting that the surface flow played a significant role in the CO 2 permeation. The updated permeability‐selectivity tradeoff curves show that this CMSM membrane compared favourably with other membrane materials reported in the literature for the removal of N 2 and CO 2 from CH 4 for natural gas upgrading.