Abstract: Embodiments of the present invention generally disclose membrane-based systems and methods for the separation of propylene and propane that overcome certain issues associated with prior art devices and take advantage of a temperature drop across the associated separation membrane.

Abstract: A fast gas is recovered from a feed gas containing a fast gas and at least one slow gas using a gas separation membrane. A controller may control a control valve associated with a partial recycle of a permeate gas from the membrane for combining with the feed gas. A controller may control a control valve associated with the backpressure of a residue gas from the membrane.

Abstract: A hybrid gas separation membrane/cryogenic distillation method and system produces high purity gaseous methane from a gas mixture containing a majority of methane and a minority of nitrogen.

Abstract: A mixture of air and one or more halogenated alkanes is directed to a gas separation membrane where it is separated into an oxygen, nitrogen, and moisture-enriched and halogenated alkane-depleted permeate and a halogenated alkane-enriched and oxygen, nitrogen, and moisture-depleted retentate. The retentate is directed to a cryogenic condenser where an amount of halogenated alkane is condensed therein.

Abstract: A method of separating CO2 from a hydrocarbon gas inlet stream that is within predetermined pressure and temperature ranges, including the steps of subjecting the inlet stream to fractional distillation providing a CO2 bottom product stream and a distillation overhead stream, passing the distillation overhead stream to the inlet of a primary reflux drum producing a primary reflux liquid stream and a hydrocarbon vapor stream, subjecting the hydrocarbon vapor stream to membrane separation to provide a hydrocarbon product stream and a permeate stream, compressing the permeate stream and recycling the compressed permeate stream to the inlet of the primary reflux drum thereby providing a CO2 liquid product and a hydrocarbon gas product.

Abstract: A storage tank for compressed natural gas (CNG) comprises a hydroxy-phenoxyether polymermethane barrier liner and a fiber composite outer shell. The hydroxy-phenoxyether polymer has a methane transmission rate of not more than about 50 cc-mil/100 in.sup.2 -day (19.5 cm.sup.3 -mm/m.sup.2 -atm-day) at 25.degree. C. and 2000 psi (13,800 kPa) methane pressure.

Abstract: This invention relates to novel poly(arylene ether ketimine) gas separation membranes and a process for separating gases using such membranes.

Abstract: The invention releates to semi-permeable gas separation membranes derived from oligomers containing reactive end groups.

Abstract: The invention relates to novel meta, parabisphenol based condensation uncross-linked polymer membranes and a method of separating gases using such membranes.

Abstract: The invention relates to novel aryl carbonate cyanoaryl ether gas separation membranes and a method of separating gases using such membranes.

Abstract: The invention relates to novel benzotrifluoride aryl ether membranes and a process for separating gases using such membranes.

Abstract: The invention is a process for separating hydrogen from gas mixtures using a semi-permeable membrane consisting predominantly of polycarbonates derived from tetrahalobisphenols such as tetrabromobisphenol.

Abstract: This invention relates to novel polyimide gas separation membranes derived from alicyclic dianhydrides and aliphatic, alicyclic, or aromatic diamines, and a process for using such membranes.

Abstract: A process for the preparation of a membrane comprising bisphenol-based polycabonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated wherein the halogen is Cl or Br, and the membrane prepared by such process.

Abstract: The invention is a composition useful for the preparation of POWADIR membranes of a bisphenol-based polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated, wherein the halogen is Cl or Br, the composition comprising (i) a bisphenol-based polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated, wherein the halogen is Cl or Br, (ii) a solvent for such polycarbonate, and (iii) a non-solvent for such polycarbonate. The composition is useful for extruding membranes wherein the membranes formed are POWADIR membranes with a discriminating region capable of separating oxygen from nitrogen.The composition of this invention allows the formation of membranes with excellent physical properties, good separation factors for oxygen and nitrogen, with excellent fluxes.

Abstract: The invention is a semi-permeable hollow fiber gas separation membrane possessing a non-external discriminating region fabricated from hydrophobic polymeric materials possessing less than about 1 weight percent equilibrium water content at about 25.degree. C. The invention includes a process for making such membranes as well as a method of using such membranes.

Abstract: The invention is a semi-permeable membrane which comprises a polymeric matrix with two porous surfaces and a region which functions to separate one or more gases from one or more other gases.The membranes of this invention exhibit excellent separation factors and flux. Such membranes are less prone to being damaged due to handling and exposure to contaminants due to the internal region which affects the separation, as the porous surfaces function to protect such region.

Abstract: The invention is a process for the preparation of a POWADIR membrane comprising bisphenol-based polycarbonates wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated wherein the halogen is Cl or Br, and the membrane prepared by such process.