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

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• 作者：Shiguang Li ; Janna G. Martinek ; John L. Falconer ; Richard D. Noble ; and Tracy Q. Gardner
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2005
• 出版时间：April 27, 2005
• 年：2005
• 卷：44
• 期：9
• 页码：3220 - 3228
• 全文大小：292K
• 年卷期：v.44,no.9(April 27, 2005)
• ISSN：1520-5045

文摘

SAPO-34 membranes on stainless steel, tubular supports separated CO₂ from CH₄ at feedpressures up to 3.1 MPa. The highest CO₂ permeance was 2.4 × 10^-7 mol/(m² s Pa) for a 50/50feed mixture at a pressure drop of 0.14 MPa. For a pressure drop of 3 MPa, the CO₂/CH₄separation selectivities at 253 K were 140-150; at lower pressure drops, the highest selectivitywas 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 basedon competitive adsorption. As transmembrane pressure drop increased, both CO₂ flux and CO₂permeate concentration increased for a 50/50 mixture. The flux pressure dependence was modeledby 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 CH₄adsorption.