| 摘要 |
PURPOSE:To concentrate water solution containing organic substances efficiently by vaporizing organic substances, bringing the same into contact with one side of an aromatic polyimide gas separating membrane at the temperature of 70 deg.C or more and removing selectively water vapor. CONSTITUTION:Gas containing organic substance vapor and water vapor is prepared by evaporating and vaporizing organic substance solution such as ethanol water solution, which is heated by a heater or the like up to 70 deg.C or more. Then, said gas is brought into contact with an aromatic polyimide hollow yarn membrane formed by polymerizing tetracarboxylic acid component constituted of 100mol.% 3,3',4,4'-biphenyl tetracarboxylic acid bianhydride, and a diamine component composed of 60mol.%, 4,4'-diaminophenyl ether, 30mol.% 3,5-diamino benzoic acid and 10mol.% of 4,4'-diaminodiphenyl methane, and the water vapor is permeated selectively to prepare concentrated gas mixture containing organic substance vapor.
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