Experimental studies of gas permeation through microporous silica membranes

✍ Scribed by Tomohisa Yoshioka; Eisuke Nakanishi; Toshinori Tsuru; Masashi Asaeda

• Publisher: American Institute of Chemical Engineers
• Year: 2001
• Tongue: English
• Weight: 270 KB
• Volume: 47
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.690470916

✦ Synopsis

Permeation mechanism of inorganic gases was studied experimentally and theoretically through microporous silica membranes prepared by the sol ᎐ gel method. Inorganic gas permeation was measured using the membranes with subnano pores in diameter. The permeance of He increased with increasing temperature for ®arious cases, while that of CO , O and N decreased. In particular, the obser®ed temperature depend-2 2 2 ency of CO was greater than those of other gases. In such small pores, the interaction 2 energy between a permeant molecule and the pore wall can affect gas-permeation properties. A simple gas-permeation model is used considering the effect of the attracti®e or repulsi®e pore-wall potential field, which de®iates from the ambient gas phase of the gas ( ) molecule concentration pressure in a pore. The model can explain the experimental gas-permeation properties successfully. Potential cur®es of CO and N in a silica pore 2 2

were also calculated to predict the permeation ratio of CO rN . This model can help 2 2 understand further the gas-permeation mechanism in micropores.