Abstract: The invention concerns carbon molecular sieve membranes (“CMS membranes”), and more particularly the use of such membranes in gas separation. In particular, the present disclosure concerns an advantageous method for producing CMS membranes with desired selectivity and permeability properties. By controlling and selecting the oxygen concentration in the pyrolysis atmosphere used to produce CMS membranes, membrane selectivity and permeability can be adjusted. Additionally, oxygen concentration can be used in conjunction with pyrolysis temperature to further produce tuned or optimized CMS membranes.

Abstract: The present invention relates to new fibers, new processes of using said fibers, and new sheath dope compositions for multi-layer spinning processes. The fibers comprise a porous core and a sheath surrounding said porous core. The fibers may be useful in, for example, processes for removing low level contaminants like sulfur compounds from a gas stream like natural gas.

Abstract: Compositions and processes are disclosed for economical separation of fluid mixtures. Broadly, the present invention discloses ionic polymer compositions that are useful for perm-selective membrane separations. More particularly, ionic polymers of the invention comprise a plurality of repeating structural units having as a constituent part thereof organic ionic moieties consisting of nitrogen containing anions and/or cations. In the form of non-porous membranes, ionic polymers of the invention facilitate recovery of purified organic and inorganic products from fluid mixtures by means of perm-selective membrane separations. The present invention also provides methods for forming the ionic polymers, for example by treating selected nitrogen-containing organic polymers with acids, or treating a polymeric material comprising a plurality of carboxylate groups with an amine.

Abstract: Processes are disclosed for production of value-added products from fluid admixtures of hydrocarbon compounds at least one of which is an aromatic hydrocarbon compound, by means of one or more devices using perm-selective polymeric membranes. More particularly, processes of the invention comprise separations using aromatic-selective polymeric materials comprising long-chain polymeric molecules in which recurring amide and imide linkages are part of the main polymer chain. Processes of the invention advantageously employ aromatic-selective membranes to separate an aromatic enriched stream from gaseous and/or liquid mixtures comprising one or more aromatic hydrocarbon compounds thereby producing a stream comprising the remaining compounds which may include alkenes and/or alkanes containing 3 or more carbon atoms, and/or alicyclic hydrocarbons.

Abstract: A high carbon content membrane and method for making the same are disclosed. The carbon membrane includes an asymmetric hollow filamentary carbon membrane, including a partial carbonization product of an asymmetric hollow filament including an aromatic imide polymer material. The carbon membrane is at least 95 weight percent carbon, and has a dense layer located in the outside surface portion of the hollow filamentary membrane and a porous base layer continued from the dense layer and located in the inside portion of the hollow filamentary membrane. A process for separating CO2 from natural gas is described including: contacting a mixture of CO2 and natural gas with a first side of a carbon membrane in a manner to cause a portion of the mixture to pass through the carbon membrane to a permeate side. The resulting mixture on the permeate side becomes enriched in CO2 over that of the mixture on the first side. The contacting step occurs at a pressure of at least about 200 psia.

Abstract: Carbon dioxide (CO2) is separated from natural gas in a downhole environment. An asymmetric hollow-carbon fiber membrane is positioned in a production string within a wellhole through which a CO2-containing natural gas is being conducted. The carbon fiber comprises a partial carbonization product of a hollow filament including an aromatic imide polymer material. The carbon membrane is at least 90 weight percent carbon, and has a dense fiber layer located in the outside surface portion of the membrane and a porous base fiber layer contiguous with the dense layer and located in the inside portion of the membrane. The natural gas is passed through the membrane at a pressure of at least about 200 psia.

Abstract: The invention includes a process for separating CO2 from natural gas including: contacting a mixture of CO2 and natural gas with a first side of a carbon membrane in a manner to cause a portion of the mixture to pass through the carbon membrane to a permeate side. The resulting mixture on the permeate side becomes enriched in CO2 over that of the mixture on the first side. The carbon membrane includes an asymmetric hollow filamentary carbon membrane, including a partial carbonization product of an asymmetric hollow filament including an aromatic imide polymer material. The carbon membranes is at least 95 weight percent carbon, and has a dense layer located in the outside surface portion of the hollow filamentary membrane and a porous base layer continued from the dense layer and located in the inside portion of the hollow filamentary membrane. The contacting in step occurs at a pressure of at least about 200 psia.

Abstract: The invention includes a process for separating CO2 from natural gas including: contacting a mixture of CO2 and natural gas with a first side of a carbon membrane in a manner to cause a portion of the mixture to pass through the carbon membrane to a permeate side. The resulting mixture on the permeate side becomes enriched in CO2 over that of the mixture on the first side. The carbon membrane includes an asymmetric hollow filamentary carbon membrane, including a partial carbonization product of an asymmetric hollow filament including an aromatic imide polymer material. The carbon membrane is at least 95 weight percent carbon, and has a dense layer located in the outside surface portion of the hollow filamentary membrane and a porous base layer continued from the dense layer and located in the inside portion of the hollow filamentary membrane. The contacting step occurs at a pressure of at least about 200 psia.