Abstract: A surface modified gas separation membrane having improved permselective properties for separating a mixture of gases as compared to the unmodified membrane, is described. The gas separation membrane is made by a process comprising the steps of coating a surface unmodified gas separation membrane with a solution of a coating material, wherein the coating material is an organic material having at least one site of unsaturation; heating the coated gas separation membrane; and contacting the heated coated gas separation membrane with at least one oxidizing agent for a time effective to surface modify the gas separation membrane to produce the surface modified gas separation membrane having improved permselectivity.

Abstract: A gas-separation membrane enables the economical separation of noble gases, especially xenon, from oxygen, nitrogen, carbon dioxide or mixtures of the latter gases. The membrane of the present invention includes a thin discriminating layer selected from the group consisting of polycarbonate, polyester, and polyestercarbonate. In the preferred embodiment, the thin discriminating layer includes material selected from the bisphenolic group consisting of 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, and 9,9-bis(3,5-dibromo-4-hydroxyphenyl)fluorene. The invention also includes the method of using the membrane, made as described above, either in a single-stage process or in a multiple-stage process, to provide the desired product gas. Several membrane units, made according to the present invention, may be manifolded together so as to operate in a parallel fashion, to provide an increased volume of product gas at the same desired purity.

Abstract: A method for preparing a surface modified gas separation membrane, wherein said membrane has improved permselective properties for separating a mixture of gases as compared to the unmodified membrane, is described. The method comprises coating a surface unmodified gas separation membrane with a solution of a coating material, wherein the coating material is an organic material having at least one site of unsaturation; heating the coated gas separation membrane; and contacting the heated coated gas separation membrane with at least one oxidizing agent for a time effective to surface modify the gas separation membrane to produce the surface modified gas separation membrane having improved permselectivity.

Abstract: A gas separation membrane device comprising an internally staged permeator containing a three dimensional array of hollow fiber membranes grouped into multiple sets in intimate contact with each other is described. The incorporation of the internally staged permeator, particularly, the arrangement of the multiple sets of fiber membranes in intimate contact with each other, results in improved efficiency of the device, especially for feed streams or membrane types that lead to high permeate flow rate that result in excessive shellside pressure drops.

Abstract: A boreside feed gas separation membrane device containing primarily hollow fiber membranes with discrete flow channels incorporated into the bundle to allow for pressure removal of the permeate gas collected on the shellside of the device is described. The flow channels minimize pressure drop and/or the build-up of back pressure on the shellside of the device while maintaining proper counter-current flow patterns in the device. The incorporation of flow channels results in improved efficiency of the device, especially for feed streams or membrane types that lead to high permeate flow rate that result in excessive shellside pressure drops.

Abstract: A macroporous polymeric adsorbent is used to remove oil mist and oil vapors from compressed air produced by an oil-lubricated air compressor prior to feeding the compressed air to an air separation membrane system. The macroporous polymeric adsorbent, previously known only for its ability to extract low molecular weight volatile organic compounds from liquids and gases, retains its ability to extract the oil for extended periods of time and outperforms the commonly used activated carbon of the prior art.

Abstract: A macroporous polymeric adsorbent is used to remove oil mist and oil vapors from compressed air produced by an oil-lubricated air compressor prior to feeding the compressed air to an air separation membrane system. The macroporous polymeric adsorbent, previously known only for its ability to extract low molecular weight volatile organic compounds from liquids and gases, retains its ability to extract the oil for extended periods of time and outperforms the commonly used activated carbon of the prior art.

Abstract: Hollow fiber membrane modules are manufactured by weaving hollow fiber membranes into a web while the fibers still contain a residual amount of the organic liquids used in the extrusion of the fibers. The web once formed is then passed through a final solvent extraction stage, followed by drying and heating to fix the final form and permeation characteristics of the membranes, and finally rolling the web into a bundle which forms the interior of the module. The hollow fibers are woven as fill in the web.