Long-term durability tests of dimethoxydiphenylsilane-derived silica membranes for purifying H2 from H2-toluene mixtures were carried out. The silica membrane maintained excellent H2-selective performance under H2-toluene mixture condition, despite H2 permeance was decreased from its initial value. Membrane performance changed in two steps. Performance initially decreased rapidly, and then decreased very slowly. We also examined membrane performance using H2-dehydrated toluene and H2-water mixtures, and it was indicated that adsorption of toluene molecules and water molecules dissolved in toluene on membrane surfaces was the predominant factor for the rapid initial decrease. Water molecules present within toluene also affected the subsequent slower decrease. These decrements were partially recovered by placing the membranes in an H 2 stream. Incomplete recovery during regeneration was due to the strong effect of water molecules dissolved in toluene, even though the amount of water was quite small.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering