Gas separation membrane module and method for gas separation

Abstract

A process for producing nitrogen-rich air by feeding high temperature air at 150° C. or more to an air separation membrane module is described. After being placed at 175° C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

1 . (canceled) 
     
     
         2 . A separation membrane module used under high-temperature conditions, comprising:
 a hollow fiber bundle including a number of hollow fiber membranes with selective permeability;   a cylindrical vessel housing the hollow fiber bundle;   a tube sheet placed at the end of the hollow fiber bundle, said tube sheet fixes the end of the bundle to the end of the cylindrical vessel and separates the inside of the cylindrical vessel from the outside; and   an annular sealing member for sealing between the outer surface of the tube sheet and the inner surface of the cylindrical vessel;   wherein the tube sheet does not comprise a stepped portion at its periphery on which the annular sealing member is to be mounted.   
     
     
         3 . A separation membrane module used under high-temperature conditions, comprising:
 a hollow fiber bundle including a number of hollow fiber membranes with selective permeability;   a cylindrical vessel housing the hollow fiber bundle; and   a tube sheet placed at the end of the hollow fiber bundle, said tube sheet fixes the end of the bundle to the end of the cylindrical vessel and separates the inside of the cylindrical vessel from the outside;   wherein (i) the tube sheet is made of material having a larger thermal expansion coefficient than that of material for the cylindrical vessel, and wherein (ii) there is a gap between the outer surface of the tube sheet and the inner surface of the cylindrical vessel at normal temperature, whereas the tube sheet can expand by heating to a predetermined temperature, so that its outer surface adheres tightly to the inner surface of the cylindrical vessel to provide sealing effect.   
     
     
         4 . A gas separation membrane module, comprising:
 a hollow fiber bundle including a number of hollow fiber membranes with selective permeability;   a cylindrical vessel housing the hollow fiber bundle;   a tube sheet placed at the end of the hollow fiber bundle, said tube sheet fixes the end of the bundle to the end of the cylindrical vessel and separates the inside of the cylindrical vessel from the outside;   a cap at the end of the cylindrical vessel; and   a tubular member for forming a channel communicating the inside with the outside of the cylindrical vessel, said tubular member penetrating both a part of the cylindrical vessel and a part of the cap along radial direction.   
     
     
         5 . The gas separation membrane module of  claim 4 , comprising
 a fixing member to be inserted into a part of the peripheral wall of the cap, to fix the cap and the cylindrical vessel each other.   
     
     
         6 . A gas separation membrane module, comprising:
 a hollow fiber bundle including a number of hollow fiber membranes with selective permeability;   a cylindrical vessel housing the hollow fiber bundle;   a tube sheet placed at the end of the hollow fiber bundle, said tube sheet fixes the end of the bundle to the end of the cylindrical vessel and separates the inside of the cylindrical vessel from the outside;   a cap at the end of the cylindrical vessel; and   a fixing member to be inserted into a part of the peripheral wall of the cap, to fix the cap and the cylindrical vessel each other.   
     
     
         7 . A gas separation membrane module, comprising:
 a hollow fiber bundle including a number of hollow fiber membranes with selective permeability;   a cylindrical vessel housing the hollow fiber bundle;   a tube sheet placed at the end of the hollow fiber bundle, said tube sheet fixes the end of the bundle to the end of the cylindrical vessel and separates the inside of the cylindrical vessel from the outside;   a cap at the end of the cylindrical vessel; and   an annular sealing member for sealing between the outer surface of the tube sheet and the inner surface of the cylindrical vessel;   wherein the cap is fixed to the cylindrical vessel by (i) using a thread formed in a part of the inner surface of the cap and a thread formed in an opposite part of the outer surface of the cylindrical vessel, or (ii) using a binder for binding a flange of the cap and a corresponding flange of the cylindrical vessel.   
     
     
         8 . The gas separation membrane module of  claim 7 , wherein the annular sealing member further seals between the cap and the cylindrical vessel.