Abstract: An air dehydration membrane module is provided with a sweep gas which is taken from the waste gas of a pressure swing adsorption (PSA) unit. No additional compressor is required, other than the compressor forming part of the PSA unit. In another embodiment, the sweep gas includes the combination of dried product gas, taken from the dehydration membrane module, and a supplemental gas, which may be ambient air, or permeate gas from an air separation membrane, or waste gas from a PSA unit. An air ejector combines the streams, without the use of an additional compression step, and the combined gas is used as a sweep stream for the dehydration module. The invention also includes the method of selecting an optimum point at which the sweep gas is injected into the module.

Abstract: An air dehydration membrane module is provided with a sweep gas which is taken from the waste gas of a pressure swing adsorption (PSA) unit. No additional compressor is required, other than the compressor forming part of the PSA unit. In another embodiment, the sweep gas includes the combination of dried product gas, taken from the dehydration membrane module, and a supplemental gas, which may be ambient air, or permeate gas from an air separation membrane, or waste gas from a PSA unit. An air ejector combines the streams, without the use of an additional compression step, and the combined gas is used as a sweep stream for the dehydration module. The invention also includes the method of selecting an optimum point at which the sweep gas is injected into the module.

Abstract: Compressed natural gas is produced by a compressor, located near a natural gas well. The compressor being driven by a gas engine. A portion of the compressed natural gas is diverted, and passed through a dehydration membrane, and also through a gas-separation membrane which selects for carbon dioxide. The result is a natural gas stream which is relatively dry, and relatively free of carbon dioxide. This stream is used as fuel for the gas engine which drives the compressor. The permeate gases from the membrane may be recycled. The system enables the natural gas to be compressed efficiently, by providing a conditioned fuel gas for driving the compressor.

Abstract: A gas separation module includes fibers formed of a membrane which exhibits selectivity between gaseous components to be separated. The fibers are partially coated with a solution which enhances their selectivity, the fibers being uncoated in the vicinity of their feed ends. The partially coated fibers provide a good compromise between the goals of improved selectivity and enhanced product flow. The gaseous component that permeates through the membrane is made to flow in a direction opposite that of the main gas feed, due to a baffle that directs the permeate in the desired direction. The invention also includes a method and apparatus for making the partially coated module.

Abstract: A gas-separation module allows a sweep gas to be introduced at selectively variable locations, and in selectively varying amounts, along the length of the module. The sweep gas enters the module through a perforated conduit. A slotted sleeve, disposed within the conduit, selectively blocks and unblocks perforations in the conduit. Rotation of the sleeve causes slots to come into, or out of, registration with the perforations. The sleeve permits varying amounts of sweep gas to be introduced at different locations along the length of the module. Rotation of the sleeve changes the profile of introduction of sweep gas, and can be used to optimize the performance of the module for each of a set of different pressure conditions.

Abstract: Oxygen, or other gas, of moderate purity is produced in a fiber membrane module. A diluent gas, such as air, is introduced into the module, on the shell side of the fibers, so as to mix with oxygen which has permeated through the fibers. The diluent gas not only reduces the concentration of oxygen in the product stream, to make oxygen of moderate purity, but also reduces the partial pressure of oxygen on the shell side of the fibers, thus enhancing the permeation of oxygen through the fibers. The invention can therefore enhance the productivity of the module, and/or reduce the energy required to operate the module.

Abstract: A gas separation module includes fibers formed of a membrane which exhibits selectivity between gaseous components to be separated. The fibers are partially coated with a solution which enhances their selectivity, the fibers being uncoated in the vicinity of their feed ends. The partially coated fibers provide a good compromise between the goals of improved selectivity and enhanced product flow. The gaseous component that permeates through the membrane is made to flow in a direction opposite that of the main gas feed, due to a baffle that directs the permeate in the desired direction. The invention also includes a method and apparatus for making the partially coated module.

Abstract: A gas-separation module allows a sweep gas to be introduced at selectively variable locations, and in selectively varying amounts, along the length of the module. The sweep gas enters the module through a perforated conduit. A slotted sleeve, disposed within the conduit, selectively blocks and unblocks perforations in the conduit. Rotation of the sleeve causes slots to come into, or out of, registration with the perforations. The sleeve permits varying amounts of sweep gas to be introduced at different locations along the length of the module. Rotation of the sleeve changes the profile of introduction of sweep gas, and can be used to optimize the performance of the module for each of a set of different pressure conditions.

Abstract: An air dehydration membrane is made of a hydrophilic polymer having a permeability for water vapor which is greater than its permeability for air, and having low selectivity between oxygen and nitrogen. The membrane has a hydrophilic coating, which itself may be a polymer. The coating does not affect the selectivity of the coated membrane with respect to oxygen and nitrogen, but does increase selectivity of the membrane with respect to water vapor. A preferred material for the membrane is polysulfone. Preferred materials for the coating are poly vinyl alcohol and Triton X-100. The membrane is selected such that the dominant mechanism for gas flow through the membrane is Knudsen flow. The membranes are made at low cost, and can outperform existing commercial membranes in either volumetric productivity or product recovery.

Abstract: A gas separation module includes fibers formed of a membrane which exhibits selectivity between gaseous components to be separated. The fibers are partially coated with a solution which enhances their selectivity, the fibers being uncoated in the vicinity of their feed ends. The partially coated fibers provide a good compromise between the goals of improved selectivity and enhanced product flow. The gaseous component that permeates through the membrane is made to flow in a direction opposite that of the main gas feed, due to a baffle that directs the permeate in the desired direction. The invention also includes a method and apparatus for making the partially coated module.

Abstract: An air dehydration membrane is made of a hydrophilic polymer having a permeability for water vapor which is greater than its permeability for air, and having low selectivity between oxygen and nitrogen. The membrane has a hydrophilic coating, which itself may be a polymer. The coating does not affect the selectivity of the coated membrane with respect to oxygen and nitrogen, but does increase selectivity of the membrane with respect to water vapor. A preferred material for the membrane is polysulfone. Preferred materials for the coating are poly vinyl alcohol and Triton X-100. The membrane is selected such that the dominant mechanism for gas flow through the membrane is Knudsen flow. The membranes are made at low cost, and can outperform existing commercial membranes in either volumetric productivity or product recovery.

Abstract: A system and method for separating air into components uses an air dehydration membrane for removing water vapor from compressed air. Dried compressed air is then directed, from the dehydration membrane, into a gas separation module which may be a membrane system, different from the air dehydration membrane, or a pressure swing adsorption (PSA) system. The air dehydration membrane is made of a hydrophilic polymer having a permeability for water vapor which is greater than its permeability for air, and having low selectivity between oxygen and nitrogen. The air dehydration membrane has a hydrophilic coating, which itself may be a polymer. The coating does not affect the selectivity of the coated dehydration membrane with respect to oxygen and nitrogen, but does increase selectivity of the membrane with respect to water vapor.

Abstract: An enhanced oil recovery process includes non-cryogenically generating a relatively inert gas, such as nitrogen, or nitrogen-enriched air, near the site of an oil-bearing formation. The relatively inert gas is injected into the formation, so as to displace oil from the formation. One or more off-gases, also obtained from the formation with the oil, are separated from the oil, compressed, and recycled into the formation. The use of the compressed off-gas therefore reduces the amount of relatively inert gas required, and reduces the required size and energy consumption of the equipment used to produce the inert gas. The invention therefore substantially reduces the cost of an enhanced oil recovery process.

Abstract: An in-situ combustion process heats an oil-bearing formation so as to reduce the viscosity of heavy oil, and/or to extract oil from solid or semi-solid materials in the formation. Oxygen-enriched air for the combustion is generated non-cryogenically at the surface, preferably with a membrane system or a pressure swing adsorption (PSA) unit. The oxygen-enriched air may be blended with other air to adjust its oxygen content, and is then compressed at the surface, and conveyed into an injection well. The oxygen-enriched air is especially intended for use in a toe-to-heel in-situ combustion process, in which combustion proceeds along a horizontal well. Nitrogen resulting from the production of the oxygen-enriched air may be used to compress the oxygen-enriched air, or for other purposes.

Abstract: An air dehydration membrane is made of a hydrophilic polymer having a permeability for water vapor which is greater than its permeability for air, and having low selectivity between oxygen and nitrogen. The membrane has a hydrophilic coating, which itself may be a polymer. The coating does not affect the selectivity of the coated membrane with respect to oxygen and nitrogen, but does increase selectivity of the membrane with respect to water vapor. Preferred materials for the membrane are polysulfone and poly ether sulfone. Preferred materials for the coating are poly vinyl alcohol and Triton X-100. The membranes are made at low cost, and can outperform existing commercial membranes in either volumetric productivity or product recovery.

Abstract: A gas separation system comprising one or more ceramic membranes is described. The system, particularly, the arrangement of the ceramic membranes and/or other polymeric membranes or PSA systems, results in maximum durability of the ceramic membranes.

Abstract: A gas separation system comprising one or more ceramic membranes is described. The system, particularly, the arrangement of the ceramic membranes and/or other polymeric membranes or PSA systems, results in maximum durability of the ceramic membranes.

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.