Mixed gases separation by fine porous freeze-dried cellulose acetate membrane

✍ Scribed by A. Tanioka; K. Ishikawa; A. Kakuta; M. Kuramoto; M. Ohno

• Book ID: 102733177
• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 725 KB
• Volume: 29
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1984.070290213

✦ Synopsis

A freeze-dried cellulose acetate membrane with high permeability and high separation factor was prepared. In the successive membrane process, the heat treatment temperature was 80°C for constant period of 10 min, acetone evaporation time was between 4 and 6 min, and the membrane was fixed during drying to prevent shrinkage. Gas permeabilities for such a membrane were inversely proportional to the square root of molecular weight, suggesting that the mechanism of gas flow through this membrane was Knudsen flow. Separation factors for HTHe, Ar-Kr, NTKr, He-Ne, HTNe, He-Ar, Ar-Hz, He-Kr, Ar-He, and He-HZ were measured. These factors were higher than those of membranes reported already. Separation efficiency largely depended upon the combinations of mixed gases. The combination of two atom molecules and one atom molecule lowered the separation efficiency compared with the combination of one atom molecule and one atom molecule.