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).

A separator (104) includes a porous polyetherimide membrane comprising a plurality of pores, wherein at least a portion of the pores comprise an electrolyte composition comprising an ionic liquid.

The present disclosure relates to crown ether-containing co-polyimides, and to membranes containing such. The present disclosure also relates to methods of using the membranes for gas separation applications.

In one aspect, the disclosure relates to azide-containing poly(ether imide) polymers (PEIs; N.sub.3-PEI-N.sub.3) synthesized via a heterogenous diazotizationazidation reaction. In one aspect, the azide-containing PEIs can be solution-cast into films and then thermally crosslinked. In a further aspect, the crosslinked PEIs (X-PEIs) exhibit superior thermal and mechanical properties. In a still further aspect, X-PEIs display outstanding resistance to classical solvents for conventional PEI, including THF, DCM, chloroform, DMF, and NMP. In another aspect, with an initial number average molecular weight (M.sub.n) of 8.9 kDa, the disclosed azide-containing PEIs have a high crosslinking density and thus possess desirable thermal, mechanical, and solvent resistance properties.

A carbon molecular sieve (CMS) membrane may advantageously be made by pyrolyzing a membrane precursor composition comprised of a carbon forming polymer (e.g., polyimide) blended with a polyvinylidene chloride copolymer (PVDC), the polyvinylidene chloride copolymer being the reaction product of at least 60% to 97% by weight of vinylidene chloride and at least one other comonomer and the carbon forming polymer to polyvinylidene chloride copolymer has a weight ratio of greater than 1 to 99. The membrane precursor composition may be formed by dissolving the carbon forming polymer and PVDC in a solvent to form a dope solution. The dope solution may be shaped, for example, into an asymmetric hollow fiber. The asymmetric hollow fiber may be heated to a temperature to dehydrochorinate the PVDC and then subsequently heated in a non-oxidizing atmosphere to carbonize the polymers of the shaped membrane to form the CMS membrane.

A homogeneous composite substrate includes a woven cloth and at least one fiber membrane. The woven cloth includes a plurality of first fibers. The fiber membrane is disposed on at least one surface of the woven cloth, and the fiber membrane includes a plurality of second fibers, in which a material of the first fibers and a material of the second fibers are the same, a fiber diameter of each first fiber is larger than or equal to 20 ?m and smaller than or equal to 130 ?m, and a fiber diameter of each second fiber is larger than or equal to 3 ?m and smaller than or equal to 10 ?m.

A system for degassing a hydrocarbon fluid from a hydrocarbon liquid has a plurality of hollow tube membranes. The hollow tube membranes are formed of a plastic providing an inner support body and an outer selective layer which is denser than the inner support body. The inner support body is formed of spherulitic structures. A fuel supply system and a method ae also disclosed.

Disclosed herein is a porous membrane having an immobilized enzyme wherein the enzyme is immobilized within pores which are three-dimensionally connected to each other. The porous membrane having the immobilized enzyme is three-dimensionally crosslinked in a molecular level wherein nanopores of 5 to 100 nm are interconnected, so that the immobilized enzyme may be in contact with a reactant in all directions, and the reaction solution may be easily diffused, thereby proceeding with the catalytic reaction fast and conveniently without deterioration of material transport.

A mixed matrix membrane which is porous and has a cross section resembling a sponge. The membrane includes nanoparticle fillers which are also porous. The membrane may be freestanding or supported on a substrate. Methods of making the membrane by spin casting or solvent casting are described. Methods of separating a gas/organic vapor using the membrane are described.

A carbon molecular sieve (CMS) membrane is made by pyrolyzing, to a peak pyrolysis temperature T.sub.P, a hollow fiber membrane having a polymeric sheath surrounding a polymeric core, anti-substructure collapse particles present in pores formed in the polymeric core help prevent collapse of pores formed in the hollow fiber membrane before pyrolysis. The anti-substructure collapse particles are made of a material or materials that either: i) have a glass transition temperature T.sub.G higher than T.sub.P, ii) have a melting point higher than T.sub.P, or ii) are completely thermally decomposed during said pyrolysis step at a temperature less than T.sub.P. The anti-substructure collapse particles are not soluble in a solvent used for dissolution of the polymeric material of the core.