High temperature inorganic membranes for separating hydrogen
- Oak Ridge K-25 Site, TN (United States)
Effort has continued to accumulate data on the transport of gases over the temperature range from room temperature to 275{degrees}C with inorganic membranes having a range of pore radii from approximately 0.25 nm to 3 mn. An experimental alumina membrane having an estimated mean pore radius of 0.25 nm has been fabricated and tested. Extensive testing of this membrane indicated that the separation factor for helium and carbon tetrafluoride at 250{degrees}C was 59 and the extrapolated high temperature separation factor was 1,193. For safety reasons, earlier flow measurements concentrated on helium, carbon dioxide, and carbon tetrafluoride. New data have been acquired with hydrogen to verify the agreement with the other gases. During the measurements with hydrogen, it was noted that a considerable amount of moisture was present in the test gas. The source of this moisture and its effect on permeance was examined. Improvements were implemented to the flow test system to minimize the water content of the hydrogen test gas, and subsequent flow measurements have shown excellent results with hydrogen. The extrapolation of separation factors as a function of temperature continues to show promise as a means of using the hard sphere model to determine the pore size of membranes. The temperature dependence of helium transport through membranes appears to be considerably greater than other gases for the smallest pore sizes. The effort to extend temperature dependence to the hard sphere model continues to be delayed, primarily because of a lack of adequate adsorption data.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 416490
- Report Number(s):
- ORNL/FMP-95/1; CONF-9505204-; ON: DE96001412; TRN: 96:006558-0015
- Resource Relation:
- Conference: 9. annual conference on fossil energy materials, Oak Ridge, TN (United States), 16-18 May 1995; Other Information: PBD: Aug 1995; Related Information: Is Part Of Proceedings of the ninth annual conference on fossil energy materials; Cole, N.C.; Judkins, R.R. [comps.]; PB: 522 p.
- Country of Publication:
- United States
- Language:
- English
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