Study of hydrogen transport through porous aluminum and composite membranes

Porous aluminum membrane has been prepared by annealing, quenching and acid etching a commercial Al foil. Hydrogen and carbon dioxide permeation and separation properties have been measured under pressure gradient. H2H2 and CO2CO2 permeability coefficients for porous Al membrane have been found to increase with increasing etching time, whereas H2/CO2H2/CO2 selectivity first increases then decreases. In order to improve H2/CO2H2/CO2 selectivity, composite membrane has been prepared by depositing a thin layer (∼8μm) of polysulfone (PSF) on the highly porous Al membrane. The optical micrographs show that microstructures of Al grain particles and openings of etch pits are of micron order.