CERAMIC MEMBRANES FOR HYDROGEN PRODUCTION FROM COAL
The objective of this project is to develop ceramic membranes for hydrogen separation from fuel gas or synthesis gas at temperatures 400-500 C. The membrane chosen for this purpose consists of a dense silica layer coated on a porous support by chemical vapor depositrion (CVD). The support used during the reporting period was zeolite silicalite grown on macroporous alumina tubes. Chemical vapor deposition was carried out using alternating exposure of the support to silicon tetrachloride (SiCl{sub 4}) and water vapor at 400-500 C. Under these conditions it takes about twenty-five reaction cycles to narrow down the pores of the zeolite support sufficiently for separation of hydrogen from other gases. The membranes were characterized by gas adsorption for pore size distribution, scanning electron microscopy, and EDAX for elemental composition. The permeance of H{sub 2}, N{sub 2}, CO{sub 2}, n-C{sub 4}H{sub 10}, and i-C{sub 4}H{sub 10} was measured in the temperature range 100-250 C. At 150 C, the H{sub 2}:N{sub 2} permeance ratio was in the range 100-200 at a hydrogen permeance of 5-10x10{sup -8} mol/m{sub 2}-s-Pa.
- Research Organization:
- California Institute of Technology (US)
- Sponsoring Organization:
- (US)
- DOE Contract Number:
- FG26-00NT40817
- OSTI ID:
- 812539
- Country of Publication:
- United States
- Language:
- English
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