Abstract: A device for separating a gas, such as air, into components, includes a plurality of modules, each module having one or more polymeric membranes capable of gas separation. A set of valves, pipes, and manifolds together arrange the modules in one of two possible configurations. In a first configuration, the modules are arranged in parallel. In a second configuration, the modules are divided into two groups which are arranged in series. The device can be switched from parallel to series, or from series to parallel, simply by changing the positions of a small number of valves, typically three valves. The device can therefore produce gas either of higher purity, or moderate purity, depending on the settings of the valves. The device also includes improved structures for connecting the modules to inlet and outlet manifolds, and also includes devices for temporarily isolating one or more modules from the system.

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 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: An air dehydration module includes polymeric fibers for separating water vapor from air, and also includes a carbon filter material, positioned at an outlet end of the module, and within the same pressure vessel which houses the fibers. The module may generate its own sweep stream, in which case a portion of its output is directed to flow through an orifice, towards the inlet end of the module. In an alternative embodiment, the sweep gas is produced by a distinct gas-separation module, which receives an input stream from the output of the dehydration module. The dehydration module produces clean and dry air which can be used as is, or as an input stream to an air separation module.

Abstract: A device for separating a gas, such as air, into components, includes a plurality of modules, each module having one or more polymeric membranes capable of gas separation. A set of valves, pipes, and manifolds together arrange the modules in one of two possible configurations. In a first configuration, the modules are arranged in parallel. In a second configuration, the modules are divided into two groups which are arranged in series. The device can be switched from parallel to series, or from series to parallel, simply by changing the positions of a small number of valves, typically three valves. The device can therefore produce gas either of higher purity, or moderate purity, depending on the settings of the valves. The device also includes improved structures for connecting the modules to inlet and outlet manifolds, and also includes devices for temporarily isolating one or more modules from the system.

Abstract: A device for separating a gas, such as air, into components, includes a plurality of modules, each module having one or more polymeric membranes capable of gas separation. A set of valves, pipes, and manifolds together arrange the modules in one of two possible configurations. In a first configuration, the modules are arranged in parallel. In a second configuration, the modules are divided into two groups which are arranged in series. The device can be switched from parallel to series, or from series to parallel, simply by changing the positions of a small number of valves, typically three valves. The device can therefore produce gas either of higher purity, or moderate purity, depending on the settings of the valves.

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 multi-stage polymeric membrane module system separates a gas, such as air, into components of high purity. In at least two of the stages, a portion of the retentate gas is directed into the low-pressure side of the module, to act as a sweep gas. The use of the sweep gas reduces the partial pressure of permeate gas on the low-pressure side of the membrane, and therefore improves the flow of permeate through the membrane. In a preferred embodiment, there are three modules. The output streams are taken from the retentate outlet of one module, and from the permeate outlet of another module. The output streams have very high purity, relative to the number of modules required, as compared with systems of the prior art.

Abstract: An air dehydration module includes polymeric fibers for separating water vapor from air, and also includes a carbon filter material, positioned at an outlet end of the module, and within the same pressure vessel which houses the fibers. The module may generate its own sweep stream, in which case a portion of its output is directed to flow through an orifice, towards the inlet end of the module. In an alternative embodiment, the sweep gas is produced by a distinct gas-separation module, which receives an input stream from the output of the dehydration module. The dehydration module produces clean and dry air which can be used as is, or as an input stream to an air separation module.

Abstract: A device for separating a gas, such as air, into components, includes a plurality of modules, each module having one or more polymeric membranes capable of gas separation. A set of valves, pipes, and manifolds together arrange the modules in one of two possible configurations. In a first configuration, the modules are arranged in parallel. In a second configuration, the modules are divided into two groups which are arranged in series. The device can be switched from parallel to series, or from series to parallel, simply by changing the positions of a small number of valves, typically three valves. The device can therefore produce gas either of higher purity, or moderate purity, depending on the settings of the valves.

Abstract: A multi-stage polymeric membrane module system separates a gas, such as air, into components of high purity. In at least two of the stages, a portion of the retentate gas is directed into the low-pressure side of the module, to act as a sweep gas. The use of the sweep gas reduces the partial pressure of permeate gas on the low-pressure side of the membrane, and therefore improves the flow of permeate through the membrane. In a preferred embodiment, there are three modules. The output streams are taken from the retentate outlet of one module, and from the permeate outlet of another module. The output streams have very high purity, relative to the number of modules required, as compared with systems of the prior art.

Abstract: A non-cryogenic system for producing high-purity nitrogen is connected to a coiled-tubing unit. The nitrogen is produced by passing compressed ambient air through two polymeric membrane modules connected in series. The output of the second module is a stream of high-purity nitrogen, which is conveyed into a coiled tube. The nitrogen can be used for inerting the interior of the tube, or the coiled tube can be inserted into an oil well, for delivering nitrogen into the well. The use of nitrogen in a coiled tube helps to prevent corrosion in the tube.

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 gaseous component is extracted non-cryogenically from a feed gas containing condensable hydrocarbons. The feed gas is passed first through a module containing polymeric fibers useful for removing water vapor from the gas. The gas is then passed through a module containing polymeric fibers selected such that they remove some, but not all, of the carbon dioxide in the stream. The gas is then passed through a module containing polymeric fibers selected to remove at least some of the remaining carbon dioxide as well as heavy hydrocarbons, defined as C5 and heavier, from the stream. The invention is especially useful in processing raw methane taken from a well, and in producing methane which is relatively free of water vapor, carbon dioxide, and heavy hydrocarbons.

Abstract: A gas separation membrane module includes hollow polymeric fibers held within a casing, the fibers being anchored by tubesheets at the ends of the casing. A filter material, preferably made of an activated carbon fiber fabric, is integral with the module, such that all gas entering the module must pass first through the filter before reaching the fibers. The filter may have the form of a circular pad affixed to one of the tubesheets. Alternatively, the filter could be a wrap disposed around the fibers, inside the casing. In another alternative, the filter could be provided within a core tube, in cases where a feed gas is introduced through the core of the module. In another embodiment, the filter could be provided in a separate unit from the gas separation module.

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 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 gaseous component is extracted non-cryogenically from a feed gas containing condensable hydrocarbons. The feed gas is passed first through a module containing polymeric fibers useful for removing water vapor from the gas. The gas is then passed through a module containing polymeric fibers selected such that they remove some, but not all, of the carbon dioxide in the stream. The gas is then passed through a module containing polymeric fibers selected to remove at least some of the remaining carbon dioxide as well as heavy hydrocarbons, defined as C5 and heavier, from the stream. The invention is especially useful in processing raw methane taken from a well, and in producing methane which is relatively free of water vapor, carbon dioxide, and heavy hydrocarbons.

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.