Abstract: A cartridge for non-cryogenically separating a gas into components includes a plurality of hollow polymeric fibers, the fibers being anchored by a pair of tubesheets, each tubesheet being adjacent to a head, the tubesheet and head being joined by a clamshell retainer. The cartridge does not have a core tube. The fibers are enclosed within a sleeve, the sleeve being sufficiently thin so as to be a non-structural element. The cartridge may be inserted within a larger pressure vessel. The cartridge of the present invention can accommodate more fibers than comparable cartridges of the prior art, and therefore has greater throughput.

Abstract: A cartridge for non-cryogenically separating a gas into components includes a plurality of hollow polymeric fibers, the fibers being anchored by a pair of tubesheets, each tubesheet being adjacent to a head, the tubesheet and head being joined by a clamshell retainer. The cartridge does not have a core tube. The fibers are enclosed within a sleeve, the sleeve being sufficiently thin so as to be a non-structural element. The cartridge may be inserted within a larger pressure vessel. The cartridge of the present invention can accommodate more fibers than comparable cartridges of the prior art, and therefore has greater throughput.

Abstract: A gas separation module includes hollow polymeric fibers held between a pair of tubesheets. The tubesheets are mounted to a core tube, and the distance between the tubesheets is maintained constant. The core tube is formed in telescoping sections, such that the fibers are attached to the tubesheets when the core tube is in its extended position, and the core tube is then collapsed, forming slack in the fibers. The core tube includes two distinct channels, connected to receive permeate and retentate gas streams, and to carry these streams to outlet ports while keeping the streams separate. Because the tubesheets are affixed to the core tube, the tubesheets do not move under the influence of gas pressure in the module. The slack in the fibers compensates for shrinkage of the fibers, prolonging the life of the module.

Abstract: A two-stage gas-separation membrane system includes two identical membrane modules held within a single casing. A feed gas is directed into the first module, so as to produce permeate and retentate streams. One of the latter streams then becomes the feed gas for the second module, and reaches the second module through a core tube located within the module. The product of the second module is the product gas for the system. The gas streams entering the two modules flow in mutually opposite directions. This arrangement makes it feasible to provide a two-stage system while using only the number of ports that would be needed for a single stage.

Abstract: A gas separation module includes hollow polymeric fibers held between a pair of tubesheets. The tubesheets are mounted to a core tube, and the distance between the tubesheets is maintained constant. The core tube is formed in telescoping sections, such that the fibers are attached to the tubesheets when the core tube is in its extended position, and the core tube is then collapsed, forming slack in the fibers. The core tube includes two distinct channels, connected to receive permeate and retentate gas streams, and to carry these streams to outlet ports while keeping the streams separate. Because the tubesheets are affixed to the core tube, the tubesheets do not move under the influence of gas pressure in the module. The slack in the fibers compensates for shrinkage of the fibers, prolonging the life of the module.

Abstract: A two-stage gas-separation membrane system includes two identical membrane modules held within a single casing. A feed gas is directed into the first module, so as to produce permeate and retentate streams. One of the latter streams then becomes the feed gas for the second module, and reaches the second module through a core tube located within the module. The product of the second module is the product gas for the system. The gas streams entering the two modules flow in mutually opposite directions. This arrangement makes it feasible to provide a two-stage system while using only the number of ports that would be needed for a single stage.

Abstract: A polymeric fiber for use in gas separation is formed from a spin dope which includes solvent and non-solvent materials. The fiber is passed through a quench bath, and then a leach bath, in which the solvent and non-solvent are removed. The quench bath and the leach bath include sets of rollers which transport the fiber through the system. Each set of rollers in the leach bath operates at a speed which is greater than or equal to the speed of the rollers which are immediately upstream. Thus, the fiber is stretched, in different amounts, at the same time that the solvent and non-solvent are being removed, and while the fiber is still wet. The resulting fiber has been found to exhibit superior flux and selectivity properties.

Abstract: A spin dope composition produces a polymeric fiber useful in non-cryogenic gas separation. The composition includes polysulfone as the polymeric component, two solvents, in which the polymer is soluble, and a non-solvent, in which the polymer is insoluble. The solvents preferably include N-methyl-pyrrolidone (NMP) and N,N-dimethyl acetamide (DMAC), and the non-solvent preferably includes triethylene glycol (TEG). Fibers made from the present composition have been found to exhibit superior properties of gas flux and selectivity, as compared with fibers made from spin dopes having only one solvent component.

Abstract: A module having polymeric gas-separation membranes is capable of operation in extreme temperature environments. In one embodiment, the module includes polymeric fiber membranes, a tubesheet for holding the membranes, and a sleeve encasing the membranes, all of which are made of materials having coefficients of thermal expansion which differ from each other by not more than about 10%. In another embodiment, the membranes, the tubesheet, and the sleeve are all made of materials having a glass transition temperature greater than a highest anticipated temperature of operation of the module. In another embodiment, the module includes a head, and a clamshell having multiple protrusions which engage corresponding grooves in the head and in at least two grooves formed in the tubesheet.

Abstract: A module having polymeric gas-separation membranes is capable of operation in extreme temperature environments. In one embodiment, the module includes polymeric fiber membranes, a tubesheet for holding the membranes, and a sleeve encasing the membranes, all of which are made of materials having coefficients of thermal expansion which differ from each other by not more than about 10%. In another embodiment, the membranes, the tubesheet, and the sleeve are all made of materials having a glass transition temperature greater than a highest anticipated temperature of operation of the module. In another embodiment, the module includes a head, and a clamshell having multiple protrusions which engage corresponding grooves in the head and in at least two grooves formed in the tubesheet.

Abstract: A spin dope composition produces a polymeric fiber useful in non-cryogenic gas separation. The composition includes polysulfone as the polymeric component, two solvents, in which the polymer is soluble, and a non-solvent, in which the polymer is insoluble. The solvents preferably include N-methyl-pyrrolidone (NMP) and N,N-dimethyl acetamide (DMAC), and the non-solvent preferably includes triethylene glycol (TEG). Fibers made from the present composition have been found to exhibit superior properties of gas flux and selectivity, as compared with fibers made from spin dopes having only one solvent component.

Abstract: A composition for making polymeric fiber membranes, for use in non-cryogenic separation of gases, substantially improves product flow, with only a small decrease in the recovery ratio. The composition is a spin dope including tetrabromo bis-phenol A polycarbonate (TBBA-PC) and tetrabromo bishydroxyphenylfluorene polycarbonate (TBBHPF-PC), in proportions, by weight, ranging (in percent) from about 60/40 to 40/60, and n-methyl pyrrolidinone (NMP) and triethylene glycol (TEG), wherein the ratio of the amounts of NMP to TEG, by weight, is in the range of about 1.6-2.5. The spin dope is used to make hollow fibers for use in gas-separation membrane modules.

Abstract: A polymeric fiber for use in gas separation is formed from a spin dope which includes solvent and non-solvent materials. The fiber is passed through a quench bath, and then a leach bath, in which the solvent and non-solvent are removed. The quench bath and the leach bath include sets of rollers which transport the fiber through the system. Each set of rollers in the leach bath operates at a speed which is greater than or equal to the speed of the rollers which are immediately upstream. Thus, the fiber is stretched, in different amounts, at the same time that the solvent and non-solvent are being removed, and while the fiber is still wet. The resulting fiber has been found to exhibit superior flux and selectivity properties.

Abstract: A composition for making polymeric fiber membranes, for use in non-cryogenic separation of gases, substantially improves product flow, with only a small decrease in the recovery ratio. The composition is a spin dope including tetrabromo bis-phenol A polycarbonate (TBBA-PC) and tetrabromo bishydroxyphenylfluorene polycarbonate (TBBHPF-PC), in proportions, by weight, ranging (in percent) from about 60/40 to 40/60, and n-methyl pyrrolidinone (NMP) and triethylene glycol (TEG), wherein the ratio of the amounts of NMP to TEG, by weight, is in the range of about 1.6-2.5. The spin dope is used to make hollow fibers for use in gas-separation membrane modules.

Abstract: An integrated fiber membrane module for air dehydration and air separation includes dehydration and separation units disposed concentrically in a generally cylindrical module. Air flows through the outer dehydration unit, becomes dried, and is then directed, in an opposite direction, through the separation unit. The permeate gas from the separation unit serves as a sweep gas for the dehydration unit. A portion of dried gas produced by the dehydration unit may be used as a sweep gas for the separation unit, and also for the dehydration unit. The module makes it feasible to dry and separate air using a device which occupies relatively little space, and which is therefore especially suited for use in aircraft and in other cramped environments.

Abstract: An automatic lacer wraps bundles of polymeric fibers with thread, before the bundles are woven into a fabric mat and placed in a housing to form a gas-separation membrane module. A fiber bundle passes through a spool which is previously wound with thread on its outer surface. The thread is attached to the fiber bundle, so that when the bundle is moved through the spool, the thread is pulled from the spool, and automatically becomes wound around the bundle. Threads from two or more spools may be wrapped around the fiber bundle simultaneously. Lacing of the fiber bundles reduces the amount of tangling in the loom feeder, and improves the quality of modules made from the fiber bundles.

Abstract: An integrated fiber membrane module for air dehydration and air separation includes dehydration and separation units disposed concentrically in a generally cylindrical module. Air flows through the outer dehydration unit, becomes dried, and is then directed, in an opposite direction, through the separation unit. The permeate gas from the separation unit serves as a sweep gas for the dehydration unit. A portion of dried gas produced by the dehydration unit may be used as a sweep gas for the separation unit, and also for the dehydration unit. The module makes it feasible to dry and separate air using a device which occupies relatively little space, and which is therefore especially suited for use in aircraft and in other cramped environments.

Abstract: An automatic lacer wraps bundles of polymeric fibers with thread, before the bundles are woven into a fabric mat and placed in a housing to form a gas-separation membrane module. A fiber bundle passes through a spool which is previously wound with thread on its outer surface. The thread is attached to the fiber bundle, so that when the bundle is moved through the spool, the thread is pulled from the spool, and automatically becomes wound around the bundle. Threads from two or more spools may be wrapped around the fiber bundle simultaneously. Lacing of the fiber bundles reduces the amount of tangling in the loom feeder, and improves the quality of modules made from the fiber bundles.

Abstract: A tubesheet is formed at the end of a module containing polymeric material for gas separation, by immersing the end of the module in an epoxy material, or its equivalent. A vacuum, or partial vacuum, applied at or near the opposite end of the module, tends to draw the epoxy material towards the source of the vacuum, and results in a tubesheet having a desired thickness, even though the epoxy material may have relatively high viscosity. The method produces effective tubesheets, while minimizing the degree to which the tubesheet covers the otherwise useful surface area of the polymeric material. The method thus produces gas-separation modules having enhanced productivity.

Abstract: A solid polymer is recovered from a solution by the addition of a water-based solution containing a surfactant. The solutions are mixed and heated, so that the organic solvent containing the polymer is driven off, and the solid polymer can be recovered. The solid polymer is generally recovered in the form of small particles, which can be easily moved, as part of a slurry, and then dried. The process produces no hazardous waste. The by-products of the process can be re-used or discarded through ordinary channels.