| 摘要 |
PURPOSE:To separate and concentrate methane efficiently by bringing a gas mixture containing methane and carbonic acid gas into contact with a membrane of polyimide resin constituted of repeating unit represented by a specific general formula. CONSTITUTION:A polyimide membrane constituted of repeating unit represented by the formula I (R1 represents a bivalent organic radical bonded with a bivalent aromatic, alicyclic, aliphatic hydrocarbonate radical and hydrocarbonate bonded with a bivalent organic bonding radical). A gas mixture containing methane and carbonic acid gas is brought into contact with said membrane, and carbonic acid gas is permeated through the membrane selectively and methane concentration separated. Also, methane concentration separation can be carried out by laminating an elastomer polymer film on said polyimide resin membrane, forming a composite membrane and bring a gas mixture containing methane and carbonic acid gas into contact with said composite membrane. |
