Separation of light gas mixtures using SAPO-34 membranes
Continuous SAPO-34 membranes were prepared on porous alumina tubular supports, and shown to be useful for light gas separations at low and high temperatures. Single-gas permeances of CO{sub 2}, N{sub 2} and CH{sub 4} decreased with increasing kinetic diameter. For the best membrane at 300 K, the He and H{sub 2} permeances were less than that of CO{sub 2}, because He, H{sub 2}, and CO{sub 2} were small compared to the SAPO-34 pore, and differences in the heat of adsorption determined the permeance order. The smaller component permeated the fastest in CO{sub 2}/CH{sub 4}, CO{sub 2}/N{sub 2}, N{sub 2}/CH{sub 4}, H{sub 2}/CH{sub 4} and H{sub 2}/N{sub 2} mixtures between 300 and 470 K. For H{sub 2}/CO{sub 2} mixtures, which were separated by competitive adsorption at room temperature, the larger component permeated faster below 400 K. The CO{sub 2}/CH{sub 4} selectivity at room temperature was 36 and decreased with temperature. The H{sub 2}/CH{sub 4} mixture selectivity was 8 and constant with temperature up to 480 K. Calcination, slow temperature cycles, and exposure to water vapor had no permanent effect on membrane performance, but temperature changes of approximately 30 K/min decreased the membrane's effectiveness.
- Research Organization:
- Univ. of Colorado, Boulder, CO (US)
- Sponsoring Organization:
- USDOE; National Science Foundation (NSF)
- DOE Contract Number:
- FG26-98FT40123
- OSTI ID:
- 20075576
- Journal Information:
- AIChE Journal (American Institute of Chemical Engineers), Vol. 46, Issue 4; Other Information: PBD: Apr 2000; ISSN 0001-1541
- Country of Publication:
- United States
- Language:
- English
Similar Records
Highly Selective H2 Separation Zeolite Membranes for Coal Gasification Membrane Reactor Applications
SAPO-34 Membranes for N-2/CH4 separation: Preparation, characterization, separation performance and economic evaluation