Abstract: A gas separation element comprising a membrane sheet and a permeate spacer, wherein the membrane sheet comprises a porous support and a discriminating layer, CHARACTERISED IN THAT: (a) the permeate spacer has an open space volume of at least 0.0004 m3/m2; and (b) the membrane sheet has an aspect ratio of at least 1.5.

Abstract: A gas separation element comprising a membrane sheet and a permeate spacer, wherein the membrane sheet comprises a porous support and a discriminating layer, CHARACTERISED IN THAT: (a) the porous support comprises less than 10 mg/m2 of monovalent metal ions; and (b) the discriminating layer has an average thickness of at least 0.7 ?m.

Abstract: A gas separation element comprising a membrane sheet and a permeate spacer, wherein the membrane sheet comprises a porous support and a discriminating layer, CHARACTERISED IN THAT: (a) the porous support comprises less than 10 mg/m2 of monovalent metal ions; and (b) the discriminating layer has an average thickness of at least 0.7 ?m.

Abstract: A gas separation element comprising a membrane sheet and a permeate spacer, wherein the membrane sheet comprises a porous support and a discriminating layer, CHARACTERISED IN THAT: (a) the permeate spacer has an open space volume of at least 0.0004 m3/m2; and (b) the membrane sheet has an aspect ratio of at least 1.5.

Abstract: A process for separating a feed gas comprising a polar gas and a non-polar gas into a permeate gas and a retentate gas, one of which is enriched in the polar gas and the other of which is depleted in the polar gas, the process comprising passing the feed gas through a gas separation module comprising: (i) a feed carrier comprising a membrane envelope and a feed spacer located within the membrane envelope; and (ii) a permeate carrier comprising: (a) a macroporous sheet; and (b) a protective sheet; and wherein: i) the feed gas is fed along the feed spacer of the feed carrier and a part of the feed gas passes through the membrane envelope and into the permeate carrier to give the permeate gas and a part of the feed gas is rejected by the membrane to give the retentate gas; ii) the protective sheet shields at least a part of the membrane envelope from contact with the macroporous sheet; and iii) the protective sheet comprises a non-woven material.

Abstract: A process for separating a feed gas comprising a polar gas and a non-polar gas into a permeate gas and a retentate gas, one of which is enriched in the polar gas and the other of which is depleted in the polar gas, the process comprising passing the feed gas through a gas separation module comprising: (i) a feed carrier comprising a membrane envelope and a feed spacer located within the membrane envelope; and (ii) a permeate carrier comprising: (a) a macroporous sheet; and (b) a protective sheet; and wherein: i) the feed gas is fed along the feed spacer of the feed carrier and a part of the feed gas passes through the membrane envelope and into the permeate carrier to give the permeate gas and a part of the feed gas is rejected by the membrane to give the retentate gas; ii) the protective sheet shields at least a part of the membrane envelope from contact with the macroporous sheet; and iii) the protective sheet comprises a non-woven material.

Abstract: A process for separating a feed gas comprising polar and non-polar gases into a gas mixture enriched in polar gas(es) and a gas mixture depleted in polar gas(es), the process comprising passing the feed gas through a gas separation unit comprising at least two gas-separation modules in order of decreasing selectivity for the polar gas(es), wherein the feed gas entering the gas separation unit comprises 1 to 35 mol % of polar gas(es).

Abstract: A process for separating a feed gas comprising polar and non-polar gases into a gas mixture enriched in polar gas(es) and a gas mixture depleted in polar gas(es), the process comprising passing the feed gas through a gas separation unit comprising at least two gas-separation modules in order of increasing selectivity for the polar gas(es), wherein the feed gas entering the gas separation unit comprises more than 35 mol % and up to 90 mol % of polar gas(es).

Abstract: A process for separating a feed gas comprising polar and non-polar gases into a gas mixture enriched in polar gas(es) and a gas mixture depleted in polar gas(es), the process comprising passing the feed gas through a gas separation unit comprising at least two gas-separation modules in order of decreasing selectivity for the polar gas(es), wherein the feed gas entering the gas separation unit comprises 1 to 35 mol % of polar gas(es).

Abstract: A process for separating a feed gas comprising polar and non-polar gases into a gas mixture enriched in polar gas(es) and a gas mixture depleted in polar gas(es), the process comprising passing the feed gas through a gas separation unit comprising at least two gas-separation modules in order of increasing selectivity for the polar gas(es), wherein the feed gas entering the gas separation unit comprises more than 35 mol % and up to 90 mol % of polar gas(es).