Abstract: Methods and systems for producing and using multi-layer composite co-polyimide membranes, one method for producing including preparing a microporous or mesoporous membrane support material for coating; applying a sealing layer to the membrane support material to prevent intrusion into the membrane support material of co-polyimide polymer; applying a first permselective co-polyimide layer atop and in contact with the sealing layer; and applying a second permselective co-polyimide layer atop and in contact with the first permselective co-polyimide layer.

Abstract: Methods and systems for producing and using multi-layer composite co-polyimide membranes, one method for producing including preparing a microporous or mesoporous membrane support material for coating; applying a sealing layer to the membrane support material to prevent intrusion into the membrane support material of co-polyimide polymer; applying a first permselective co-polyimide layer atop and in contact with the sealing layer; and applying a second permselective co-polyimide layer atop and in contact with the first permselective co-polyimide layer.

Abstract: Co-polyimide membranes for separating components of sour natural gas including at least three distinct moieties polymerized together, the moieties including a 2,2?-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) based moiety; a 4,4?-(hexafluoroisopropylidene)dianiline (6FpDA) based moiety; and at least one component selected from the group consisting of: a 9,9-bis(4-aminophenyl) fluorene (CARDO) based moiety; a 2,3,5,6-tetramethyl-1,4-phenylenediamine (durene diamine) based moiety; a 2,2?-bis(trifluoromethyl)benzidine (ABL-21) based moiety; a 3,3?-dihydroxybenzidine based moiety; and a 3,3?-(hexafluoroisopropylidene)dianiline based moiety.

Abstract: Co-polyimide membranes for separating components of sour natural gas including at least three distinct moieties polymerized together, the moieties including a 2,2?-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) based moiety; a 2,4,6-trimethyl-m-phenylenediamine (DAM) based moiety; and at least one component selected from the group consisting of: a 4,4?-(hexafluoroisopropylidene)dianiline (6FpDA) based moiety; a 9,9-bis(4-aminophenyl) fluorene (CARDO) based moiety; a 2,3,5,6-tetramethyl-1,4-phenylenediamine (durene diamine) based moiety; a 2,2?-bis(trifluoromethyl)benzidine (ABL-21) based moiety; a 3,3?-dihydroxybenzidine based moiety; and a 3,3?-(hexafluoroisopropylidene)dianiline based moiety.

Abstract: Co-polyimide membranes for separating components of sour natural gas where embodiments can include at least three distinct moieties polymerized together, the moieties including a 2,2?-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) based moiety; a 9,9-bis(4-aminophenyl) fluorene (CARDO) based moiety; and 2,3,5,6-tetramethyl-1,4-phenylenediamine (durene diamine) based moiety.

Abstract: Co-polyimide membranes for separating components of sour natural gas including at least three distinct moieties polymerized together, the moieties including a 2,2?-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) based moiety; a 2,4,6-trimethyl-m-phenylenediamine (DAM) based moiety; and at least one component selected from the group consisting of: a 4,4?-(hexafluoroisopropylidene)dianiline (6FpDA) based moiety; a 9,9-bis(4-aminophenyl) fluorene (CARDO) based moiety; a 2,3,5,6-tetramethyl-1,4-phenylenediamine (durene diamine) based moiety; a 2,2?-bis(trifluoromethyl)benzidine (ABL-21) based moiety; a 3,3?-dihydroxybenzidine based moiety; and a 3,3?-(hexafluoroisopropylidene)dianiline based moiety.

Abstract: Co-polyimide membranes for separating components of sour natural gas including at least three distinct moieties polymerized together, the moieties including a 2,2?-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) based moiety; a 4,4?-(hexafluoroisopropylidene)dianiline (6FpDA) based moiety; and at least one component selected from the group consisting of: a 9,9-bis(4-aminophenyl) fluorene (CARDO) based moiety; a 2,3,5,6-tetramethyl-1,4-phenylenediamine (durene diamine) based moiety; a 2,2?-bis(trifluoromethyl)benzidine (ABL-21) based moiety; a 3,3?-dihydroxybenzidine based moiety; and a 3,3?-(hexafluoroisopropylidene)dianiline based moiety.

Abstract: Co-polyimide membranes for separating components of sour natural gas where embodiments can include at least three distinct moieties polymerized together, the moieties including a 2,2?-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) based moiety; a 9,9-bis(4-aminophenyl) fluorene (CARDO) based moiety; and 2,3,5,6-tetramethyl-1,4-phenylenediamine (durene diamine) based moiety.

Abstract: Compositions of and methods for separating components of a natural gas stream are disclosed. In one embodiment, the method includes receiving an inlet stream comprising natural gas, the inlet stream having an inlet pressure, and the inlet stream further comprising methane, helium, and an impurity. The method includes allowing the inlet stream to contact a block co-polyimide membrane, the block co-polyimide membrane exhibiting both higher permeability for and higher selectivity for the helium and the impurity than for the methane at the inlet pressure of the inlet stream and separating the methane from the helium and the impurity to create a retentate stream, the retentate stream comprising an increased concentration of methane relative to the inlet stream. The method also includes creating a permeate stream comprising the helium and the impurity at an increased concentration of helium and impurity relative to a concentration of helium and impurity in the inlet stream.

Abstract: Compositions of and methods for separating components of a natural gas stream are disclosed. In one embodiment, the method includes receiving an inlet stream comprising natural gas, the inlet stream having an inlet pressure, and the inlet stream further comprising methane, helium, and an impurity. The method includes allowing the inlet stream to contact a block co-polyimide membrane, the block co-polyimide membrane exhibiting both higher permeability for and higher selectivity for the helium and the impurity than for the methane at the inlet pressure of the inlet stream and separating the methane from the helium and the impurity to create a retentate stream, the retentate stream comprising an increased concentration of methane relative to the inlet stream. The method also includes creating a permeate stream comprising the helium and the impurity at an increased concentration of helium and impurity relative to a concentration of helium and impurity in the inlet stream.

Abstract: The invention relates to methods for separating CO2 from mixed gases. A stream of mixed gases passes one side of a facilitated transport membrane, while a sweep fluid, such as steam, passes the other side of the membrane, removing the CO2. The method is especially useful in the removal of CO2 from gases produced by internal combustion engines on mobile devices.