L'air Liquide, Soci&#xe9;t&#xe9; Anonyme Pour L'etude Et L'exploitation Des Proc&#xe9;d&#xe9;s Georges Claude

Chevron U.s.a. Inc.

Georgia Tech Research Corporation

Canghai Ma

Madhava R Kosuri

David J Hasse

Robert A Gagliano

Raja Swaidan

Henri Chevrel

Dean W Kratzer

William John Koros

Metallopolyimide precursor fibers for aging-resistant carbon molecular sieve hollow fiber membranes having enhanced selectivity include transition metal cations complexed with electronegative regions of a polyimide. CMS membranes are made by pyrolyzing the metallopolyimide precursor fibers. The cations are introduced by including, in the spin dope composition used to extrude the fibers, either a salt of the transition metal and an inorganic anion or a transition metal/organic ligand complex.

Metallopolyimide precursor fibers for aging-resistant carbon molecular sieve hollow fiber membranes with enhanced selectivity

Metallopolyimide precursor fibers for aging-resistant carbon molecular sieve hollow fiber membranes having enhanced selectivity include transition metal cations complexed with electronegative regions of a polyimide. CMS membranes are made by pyrolyzing the metallopolyimide precursor fibers. The cations are introduced by including, in the bore fluid used to extrude the fibers, either a salt of the transition metal and an inorganic anion or a transition metal/organic ligand complex.

A carbon molecular sieve (CMS) membrane is made by pyrolyzing, to a peak pyrolysis temperature T, 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 Thigher than T, ii) have a melting point higher than T, or ii) are completely thermally decomposed during said pyrolysis step at a temperature less than T. The anti-substructure collapse particles are not soluble in a solvent used for dissolution of the polymeric material of the core.

Composite carbon molecular sieve membranes having anti-substructure collapse particles loaded in a core thereof

Disclosed herein is a composite hollow fiber polymer membrane including a porous core layer and a selective sheath layer. The porous core layer includes a polyamide-imide polymer, or a polyetherimide polymer, and the selective sheath layer includes a polyimide polymer, which is prepared from monomers A, B, and C. The monomer A is a dianhydride of the formula wherein Xand Xare independently halogenated alkyl group, phenyl or halogen and R, R, R, R, R, and Rare independently H, alkyl, or halogen. The monomer B is a diamino cyclic compound without a carboxylic acid functionality and the monomer C is a diamino cyclic compound with a carboxylic acid functionality. The polyimide polymer further includes covalent ester crosslinks. Also disclosed herein is a method of making the composite polymer membrane and a process for purifying natural gas utilizing the composite polymer membrane.

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Newark, DE, United States of America

Canghai Ma