| 摘要 |
<p>PURPOSE:To restore the performance of a membrane, by passing gases through a gas separation membrane made of aromatic polyimide whose performance has deteriorated, while heat is being applied to the membrane. CONSTITUTION:A process to remove carbon dioxide is comprised of a compressor 2 to deliver a gas mixture such as air, a porous membrane composed of polypropylene to remove oil mist, etc., and a hollow yarn membrane 7 composed of aromatic polyimide to separate carbon dioxide. And when the separation performance of the hollow yarn membrane 7 has deteriorated, a module-free part is heated up to 120 deg.C and maintained at said temperature for an hour, while said gas mixture is blowing. This heat-treatment temperature is well above temperatures which enable the oil mist of the compressor to pass through the membrane and below the softening point of aromatic polyimide. As a result of this heat treatment, the permeation rate of the gas separation membrane can be restored.</p> |
