Membrane contactor systems for gas-liquid contact

Abstract

A membrane contactor system for removing a component from a gas, comprising a housing defining a gas flow path; a microporous membrane positioned in the housing to allow the gas to flow across the membrane, wherein the membrane comprises a structure of nodes connected by fibrils in which surfaces of the structure of nodes and fibrils define a plurality of interconnecting pores extending through the microporous membrane, wherein the plurality of interconnecting pores are configured to allow the component to diffuse therethrough; and an oleophobic coating disposed on the microporous membrane to form a coated membrane and configured to provide oleophobicity to the coated membrane without blocking the plurality of interconnecting pores.

1 . A membrane contactor system for removing a component from a gas, comprising:
 a housing defining a gas flow path;   a microporous membrane positioned in the housing to allow the gas to flow across the membrane, wherein the membrane comprises a structure of nodes connected by fibrils in which surfaces of the structure of nodes and fibrils define a plurality of interconnecting pores extending through the microporous membrane, wherein the plurality of interconnecting pores are configured to allow the component to diffuse therethrough; and   an oleophobic coating disposed on the microporous membrane to form a coated membrane and configured to provide oleophobicity to the coated membrane without blocking the plurality of interconnecting pores.   
     
     
         2 . The membrane contactor system of  claim 1 , wherein the microporous membrane is expanded polytetrafluoroethylene. 
     
     
         3 . The membrane contactor system of  claim 1 , wherein the coated membrane has an oleophobic rating of at least 2. 
     
     
         4 . The membrane contactor system of  claim 1 , wherein the coated membrane has an oleophobic rating of at least 4. 
     
     
         5 . The membrane contactor system of  claim 1 , wherein the coated membrane has an oleophobic rating of at least 6. 
     
     
         6 . The membrane contactor system of  claim 1 , wherein the coated membrane has an oleophobic rating of at least 8. 
     
     
         7 . The membrane contactor system of  claim 1 , further comprising a support layer upon which the microporous membrane is disposed. 
     
     
         8 . The membrane contactor system of  claim 7 , wherein the support layer comprises a textile material. 
     
     
         9 . The membrane contactor system of  claim 1 , wherein the microporous membrane is configured to be a hollow tube. 
     
     
         10 . The membrane contactor system of  claim 1 , wherein the oleophobic coating comprises a polymer comprising fluorinated C 1-32  hydrocarbon moieties. 
     
     
         11 . The membrane contactor system of  claim 10 , wherein the fluorinated polymer comprises units derived from polymerization of fluoro(C 1-16 )alkyl acrylates, fluoro(C 1-16 )alkyl methacrylates, perfluoro(C 1-16 )alkyl acrylates, perfluoro(C 1-16 )alkyl methacrylates, fluorinated and perfluorinated C 1-12  olefins, fluoro(C 1-12 )alkyl maleic acid esters, perfluoro(C 1-12 )alkyl maleic acid esters, fluoro(C 1-12 )alkyl (C 6-12 )aryl urethane oligomers, fluoro(C 1-12 )alkyl allyl urethane oligomers, fluoro(C 1-12 )alkyl urethane acrylate oligomers, fluoro(C 1-12 )alkyl urethane acrylate oligomers, or a combination comprising at least one of the foregoing. 
     
     
         12 . A membrane contactor system for use in separating carbon dioxide from a gaseous stream in a continuous flow process, the system comprising:
 a housing defining a gas flow path and comprising a first outlet for the carbon dioxide and a second outlet for the purified gas;   an expanded polytetrafluoroethylene microporous membrane positioned in the housing to allow the gaseous stream to flow across a side of the expanded polytetrafluoroethylene microporous membrane, wherein the expanded polytetrafluoroethylene microporous membrane comprises a structure of nodes connected by fibrils in which surfaces of the structure of nodes and fibrils define a plurality of interconnecting pores extending through the expanded polytetrafluoroethylene microporous membrane, wherein the plurality of interconnecting pores are configured to allow the carbon dioxide to diffuse therethrough;   an oleophobic enhancement coating disposed on the surfaces of the structure of nodes and fibrils to form a coated membrane and configured to provide oleophobicity to the coated membrane without blocking the plurality of interconnecting pores; and   an amine based sorbent liquid disposed on a side of the expanded polytetrafluoroethylene microporous membrane opposite the gas, wherein the amine based sorbent liquid is configured to absorb the carbon dioxide from the gaseous stream.   
     
     
         13 . The membrane contactor system of  claim 11 , wherein the coated membrane has an oleophobic rating of at least 4. 
     
     
         14 . The membrane contactor system of  claim 11 , wherein the coated membrane has an oleophobic rating of at least 6. 
     
     
         15 . The membrane contactor system of  claim 11 , wherein the coated membrane has an oleophobic rating of at least 8. 
     
     
         16 . The membrane contactor system of  claim 11 , wherein the oleophobic coating comprises a polymer comprising fluorinated C 1-32  hydrocarbon moieties. 
     
     
         17 . The membrane contactor system of  claim 16 , wherein the fluorinated polymer is comprises units derived from polymerization of fluoro(C 1-16 )alkyl acrylates, fluoro(C 1-16 )alkyl methacrylates, perfluoro(C 1-16 )alkyl acrylates, perfluoro(C 1-16 )alkyl methacrylates, fluorinated and perfluorinated C 1-12  olefins, fluoro(C 1-12 )alkyl maleic acid esters, perfluoro(C 1-12 )alkyl maleic acid esters, fluoro(C 1-12 )alkyl (C 6-12 )aryl urethane oligomers, fluoro(C 1-12 )alkyl allyl urethane oligomers, fluoro(C 1-12 )alkyl urethane acrylate oligomers, fluoro(C 1-12 )alkyl urethane acrylate oligomers, or a combination comprising at least one of the foregoing. 
     
     
         18 . The membrane contactor system of  claim 11 , wherein the amine based sorbent liquid comprises 2-amino-2-methyl-1, 3-propanediol, 2-hydroxyethyl piperazine, methyldiethanolamine, monoethanolamine, tetraethylenepentamine, triethanolamine, polyethylene imine, or a combination comprising at least one of the foregoing. 
     
     
         19 . The membrane contactor system of  claim 18 , wherein the amine based sorbent liquid further comprises a solvent, wherein the solvent comprises alcohol, cyclic ketone, ester, ether, glycerol, methoxy triethylene, glycol diacetate, polyethylene glycol, propylene carbonate, 1,2-propylene glycol, or a combination comprising at least one of the foregoing. 
     
     
         20 . A gas turbine engine comprising:
 an exhaust treatment system configured to remove carbon dioxide from a combustion exhaust stream, wherein the system comprises:   a housing defining a gas flow path and comprising a first outlet for the carbon dioxide and a second outlet for the purified exhaust;   an expanded polytetrafluoroethylene microporous membrane positioned in the housing to allow the exhaust stream to flow across a side of the membrane, wherein the membrane comprises a structure of nodes connected by fibrils in which surfaces of the structure nodes and fibrils define a plurality of interconnecting pores extending through the membrane, wherein the pores are configured to allow the carbon dioxide to diffuse therethrough;   an oleophobic enhancement coating disposed on the surfaces of structure of nodes and fibrils and configured to provide oleophobicity to the membrane without blocking the plurality of interconnecting pores; and   an amine based sorbent liquid disposed on a side of the membrane opposite the exhaust stream, wherein the amine based sorbent liquid is configured to absorb the carbon dioxide from the exhaust stream to form the purified exhaust.