High-Pressure CO2/CH4 Separation Using SAPO-34 Membranes

SAPO-34 membranes on stainless steel, tubular supports separated CO2 from CH4 at feed pressures up to 3.1 MPa. The highest CO2 permeance was 2.4 × 10-7 mol/(m2 s Pa) for a 50/50 feed mixture at a pressure drop of 0.14 MPa. For a pressure drop of 3 MPa, the CO2/CH4 separation selectivities at 253 K w...

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Bibliographic Details
Published in:Industrial & engineering chemistry research 2005-04, Vol.44 (9), p.3220-3228
Main Authors: Li, Shiguang, Martinek, Janna G, Falconer, John L, Noble, Richard D, Gardner, Tracy Q
Format: Article
Language:English
Subjects:
Applied sciences
Chemical engineering
Exact sciences and technology
Online Access:Get full text
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Summary:SAPO-34 membranes on stainless steel, tubular supports separated CO2 from CH4 at feed pressures up to 3.1 MPa. The highest CO2 permeance was 2.4 × 10-7 mol/(m2 s Pa) for a 50/50 feed mixture at a pressure drop of 0.14 MPa. For a pressure drop of 3 MPa, the CO2/CH4 separation selectivities at 253 K were 140−150; at lower pressure drops, the highest selectivity was 270. The highest CO2 flux was 21 kg/(m2 h) at 295 K and a pressure drop of 3 MPa. Separation selectivity decreased as temperature increased because separation was partly based on competitive adsorption. As transmembrane pressure drop increased, both CO2 flux and CO2 permeate concentration increased for a 50/50 mixture. The flux pressure dependence was modeled by Maxwell−Stefan diffusion for mixtures. Methane decreased the CO2 diffusion rate and, thus, decreased the CO2 flux. The CH4 flux was also lower in a mixture because CO2 inhibits CH4 adsorption.
ISSN:0888-5885
1520-5045
DOI:10.1021/ie0490177