Abstract: A membrane-based gas separation process for treating gas streams that contain methane in low concentrations. The invention involves flowing the stream to be treated across the feed side of a membrane and flowing a sweep gas stream, usually air, across the permeate side. Carbon dioxide permeates the membrane preferentially and is picked up in the sweep air stream on the permeate side; oxygen permeates in the other direction and is picked up in the methane-containing stream. The resulting residue stream is enriched in methane as well as oxygen and has an EMC value enabling it to be either flared or combusted by mixing with ordinary air.

Abstract: Processes for removing water from organic solvents, such as ethanol. The processes include distillation in two columns operated at sequentially higher pressure, followed by treatment of the overhead vapor by one or two membrane separation steps.

Abstract: Processes for removing water from organic solvents, such as ethanol. The processes include distillation in two columns operated at sequentially higher pressure, followed by treatment of the overhead vapor by one or two membrane separation steps.

Abstract: A gas separation process for treating flue gases from combustion processes, and combustion processes including such gas separation. The invention involves flowing the flue gas stream to be treated across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas to the combustor.

Abstract: A gas-separation membrane module assembly and a gas-separation process using the assembly. The assembly includes a set of tubes, each containing gas-separation membrane elements, arranged within a housing. The housing contains tube sheets that divide the space within the housing into three separate, gas-tight spaces, with the tubes mounted in the central space. Feed gas enters the tubes through apertures positioned to feed multiple membrane elements within a tube in parallel, and one or more manifolds are used to collect residue gas from the membrane elements and direct the gas to the residue port or to a second group of membrane elements within the tube. The assembly can be used in various ways to carry out gas separation processes.

Abstract: An inorganic membrane suitable for ultrafiltration or nanofiltration, and methods for making and using the membrane. The membrane has a organic polymer deposited on the feed surface, but is not able to perform separations by solution-diffusion.

Abstract: A gas-separation membrane assembly, and a gas-separation process using the assembly. The assembly incorporates multiple gas-separation membranes in an array within a single vessel or housing, and is equipped with two permeate ports, enabling permeate gas to be withdrawn from both ends of the membrane module permeate pipes.

Abstract: The invention is a pervaporation process and pervaporation equipment, using a series of membrane modules, and including inter-module reheating of the feed solution under treatment. The inter-module heating is achieved within the tube or vessel in which the modules are housed, thereby avoiding the need to repeatedly extract the feed solution from the membrane module train.

Abstract: A process for producing and recovering light alcohols, particularly ethanol, alcohol mixtures containing ethanol, and ABE mixtures (alcohol mixtures containing acetone, butanol and ethanol), using a combination of steps including fermentation, first membrane separation, dephlegmation and dehydration by second membrane separation.

Abstract: A process for removing carbon dioxide or nitrogen from gas, especially natural gas. The process uses three membrane separation stages without compression between the second and third stages.

Abstract: A process and equipment for treating natural gas produced by a well that has recently been stimulated, and that contains an undesirably high concentration of the fracturing gas used to stimulate the well. The process involves treating the gas by membrane separation, and provides for control of treatment parameters to compensate for the changing concentration of fracturing gas in the produced gas, as well as changes in gas flow rate.

Abstract: A gas-separation membrane module assembly and a gas-separation process using the assembly. The assembly includes a set of tubes, each containing gas-separation membranes, arranged within a housing. The housing contains a tube sheet that divides the space within the housing into two gas-tight spaces. A permeate collection system within the housing gathers permeate gas from the tubes for discharge from the housing.

Abstract: A reverse osmosis membrane, and methods for making and using the membrane. The membrane has a continuous, defect-free, non-porous, hydrophilic coating that reduces the susceptibility to fouling.

Abstract: A process for separating a component from a low molecular weight organic mixture by pervaporation. The process uses fluorinated membranes and is particularly useful for treating mixtures containing light organic components, such as methane, propylene or n-butane.

Abstract: A gas-separation membrane module assembly and a gas-separation process using the assembly. The assembly includes a set of tubes, each containing gas-separation membranes, arranged within a housing. The housing contains tube sheets that divide the space within the housing into three separate, gas-tight spaces, with the tubes mounted in the central space. Within this space, each tube has an aperture or hole in its wall that enables gas that has been retained on the feed side of the membranes to flow out of the tubes and into the space. The assembly can be used in various ways to carry out gas separation processes.

Abstract: A process for treating mixtures of organic components, including azeotropic mixtures. The process includes a gas- or liquid-phase membrane separation step in conjunction with a dephlegmation step to treat at least a portion of the permeate vapor from the pervaporation step. The process yields a membrane residue stream, a stream enriched in the more volatile component as the overhead stream from the dephlegmator and a condensate stream enriched in the less volatile component as a bottoms stream from the dephlegmator. Any of these may be the principal product of the process.

Abstract: A membrane-based process for separating mixtures of target gases if the gas mixture also contains C3+ hydrocarbon vapors. The process uses gas-separation membranes having a base membrane and a coating layer. The base membrane incorporates a selective layer made from a polymer selective between the light gases to be separated. The coating layer comprises a fluorinated polymer capable of protecting the base membrane from C3+ hydrocarbon vapors and liquids.

Abstract: A membrane process for treating zein solutions to increase the zein concentration in the solution. The process uses a non-porous membrane that preferentially permeates the solvent and rejects the zein. Optionally, the process can be operated as a diafiltration process to yield a concentrate of high zein purity.

Abstract: A process and corresponding apparatus for dehydrating gas, especially natural gas. The process includes an absorption step and a membrane pervaporation step to regenerate the liquid sorbent.

Abstract: A process for treating liquids containing organic compounds and water. The process includes a pervaporation step in conjunction with a dephlegmation step to treat at least a portion of the permeate vapor from the pervaporation step. The process yields a membrane residue stream, a stream enriched in the more volatile component (usually the organic) as the overhead stream from the dephlegmator and a condensate stream enriched in the less volatile component (usually the water) as a bottoms stream from the dephlegmator. Any of these may be the principal product of the process. The membrane separation step may also be performed in the vapor phase, or by membrane distillation.