Publications

Defect-free thin film membranes for H2 separation and isolation

Nenoff, T.M.; Gordon, Margaret E.; Keller, Jay O.

We have synthesized defect-free aluminosilicate and silicalite zeolite thin films supported on commercially available alpha and gamma alumina disk substrates. We have also built a permeation unit that can test both pure and mixed gases from room temperature to 250 C. Results indicate fluxes on the order of 10{sup -6} to 10{sup -7} mole/(m{sup 2}Pa sec) and excellent separation values for H{sub 2} or CO{sub 2}. For the Al/Si membrane: H{sub 2}/N{sub 2} {ge} 61, H{sub 2}/CO{sub 2} {ge} 80, H{sub 2}/CH{sub 4} = 7, CH{sub 4}/CO{sub 2} {ge} 11; for the TPA/Si membrane: H{sub 2}/N{sub 2} {ge} 61, H{sub 2}/CO{sub 2} {ge} 80, H{sub 2}/CH{sub 4} = 7, CH{sub 4}/CO{sub 2} {ge} 11. Our data show that we can use the adsorption ability plus the effective pore diameter of the zeolite to 'tune' the selectivity of the membrane. Another avenue of research is into bulk novel molecular sieve materials, with the goal of 'tuning' pore sizes to molecular sieving needs. A novel crystalline 12-ring microporous gallophosphate material is described.