Gas separation membrane system and a method of preparing or reconditioning and the use thereof

Abstract

A gas separation membrane system and a method of preparing such gas separation membrane system by providing a porous support upon which is supported a membrane layer comprising a first gas-selective material and having a membrane thickness and removing therefrom a substantial portion of the first gas-selective material from the membrane layer by the use of an ultra-fine abrasive to thereby provide the membrane layer having a reduced membrane thickness. A second gas-selective material is deposited upon the membrane layer having the reduced membrane thickness to provide an overlayer of the second gas-selective material having an overlayer thickness so as to thereby provide the gas separation membrane system having the membrane layer of the reduced membrane thickness and the overlayer of the overlayer thickness.

1 . A method of preparing a gas separation membrane system, wherein said method comprises:
 providing a porous support upon which is supported a membrane layer comprising a first gas-selective material and having a membrane thickness;   removing a substantial portion of said first gas-selective material from said membrane layer by the use of an ultra-fine abrasive to thereby provide said membrane layer having a reduced membrane thickness; and   depositing upon said membrane layer having said reduced membrane thickness an overlayer comprising a second gas-selective material and having an overlayer thickness so as to thereby provide said gas separation membrane system having said membrane layer of said reduced membrane thickness and said overlayer of said overlayer thickness.   
     
     
         2 . A method as recited in  claim 1 , wherein said membrane thickness is greater than 80 percent of the sum of said reduced membrane thickness and said overlayer thickness. 
     
     
         3 . A method as recited in  claim 1 , wherein the sum of said reduced membrane thickness and said overlayer thickness is less than said membrane thickness. 
     
     
         4 . A method as recited in  claim 1 , wherein said substantial portion of said first gas-selective material removed from said membrane layer is such that said reduced membrane thickness is in the range of from 1 to 90 percent of said membrane thickness. 
     
     
         5 . A method as recited in  claim 1 , wherein said ultra-fine abrasive includes abrading particles having an average particle diameter in the range upwardly to 3 μm. 
     
     
         6 . A method as recited in  claim 1 , wherein said membrane thickness is in the range of from 1 μm to 50 μm. 
     
     
         7 . A method as recited in  claim 1 , wherein said the sum of said overlayer thickness and said reduced membrane thickness is in the range of from 0.001 μm to 9.9 μm. 
     
     
         8 . A gas separation membrane system, comprising:
 a porous support upon which is supported a membrane layer of a first gas-selective material with a substantial portion thereof having been removed therefrom by the use of an ultra-fine abrasive to thereby provide said membrane layer having a reduced membrane thickness, wherein said membrane layer is overlaid with an overlayer of a second gas-selective material, and wherein said overlayer has an overlayer thickness so as to thereby provide said gas separation membrane system having said membrane layer of said reduced membrane thickness and said overlayer of said overlayer thickness.   
     
     
         9 . A gas separation membrane system as recited in  claim 8 , wherein said membrane thickness is greater than 80 percent of the sum of said reduced membrane thickness and said overlayer thickness. 
     
     
         10 . A gas separation membrane system as recited in  claim 8 , wherein the sum of said reduced membrane thickness and said overlayer thickness is less than said membrane thickness. 
     
     
         11 . A gas separation membrane system as recited in  claim 8 , wherein said substantial portion of said first gas-selective material removed from said membrane layer is such that said reduced membrane thickness is in the range of from 1 to 90 percent of said membrane thickness. 
     
     
         12 . A gas separation membrane system as recited in  claim 8 , wherein said ultra-fine abrasive includes abrading particles having an average particle diameter in the range upwardly to 3 μm. 
     
     
         13 . A gas separation membrane system as recited in  claim 8 , wherein said membrane thickness is in the range of from 1 μm to 50 μm. 
     
     
         14 . A gas separation membrane system as recited in  claim 8 , wherein said the sum of said overlayer thickness and said reduced membrane thickness is in the range of from 0.001 μm to 9.9 μm. 
     
     
         15 . A process for separating hydrogen from a hydrogen-containing gas stream, wherein said process comprises:
 passing said hydrogen-containing gas stream over a gas separation membrane system, comprising a porous support upon which is supported a membrane layer of a first gas-selective material with a substantial portion thereof having been removed therefrom by the use of an ultra-fine abrasive to thereby provide said membrane layer having a reduced membrane thickness, wherein said membrane layer is overlaid with an overlayer of a second gas-selective material, and wherein said overlayer has an overlayer thickness, under temperature and pressure conditions such that hydrogen from said hydrogen-containing gas stream selectively passes through said gas separation membrane system; and recovering the thus separated hydrogen.   
     
     
         16 . A process for separating hydrogen from a hydrogen-containing gas stream as recited in  claim 15 , wherein said membrane thickness is greater than 80 percent of the sum of said reduced membrane thickness and said overlayer thickness. 
     
     
         17 . A process for separating hydrogen from a hydrogen-containing gas stream as recited in  claim 15 , wherein the sum of said reduced membrane thickness and said overlayer thickness is less than said membrane thickness. 
     
     
         18 . A process for separating hydrogen from a hydrogen-containing gas stream as recited in  claim 15 , wherein said substantial portion of said first gas-selective material removed from said membrane layer is such that said reduced membrane thickness is in the range of from 1 to 90 percent of said membrane thickness. 
     
     
         19 . A process for separating hydrogen from a hydrogen-containing gas stream as recited in  claim 15 , wherein said ultra-fine abrasive includes abrading particles having an average particle diameter in the range upwardly to 3 μm. 
     
     
         20 . A process for separating hydrogen from a hydrogen-containing gas stream as recited in  claim 15 , wherein said membrane thickness is in the range of from 1 μm to 50 μm. 
     
     
         21 . A process for separating hydrogen from a hydrogen-containing gas stream as recited in  claim 15 , wherein said the sum of said overlayer thickness and said reduced membrane thickness is in the range of from 0.001 μm to 9.9 μm.