Abstract: A carbon molecular sieve (CMS) membrane is made by pyrolyzing a film or hollow fiber membrane made of a polyimide polymer or copolymer essentially consisting of repeating units of dianhydride-derived units and diamine-derived units. At least 50% of the dianhydride-derived units are derived from 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane (6FDA). At least 50% of the diamine-derived units are derived from 2,5-diethyl-6-methyl-1,3-diamino benzene (DETDA).

Abstract: A first gas present at low concentration in a source gas is recovered from the source gas at a relatively high recovery using first and second gas separation membrane stages. The second stage permeate gas is divided into first and second portions. The first portion is a first product gas a majority of which is the first gas. The second portion and the permeate gas from the first stage are both fed to the compressor and then to the second stage gas separation membrane. The second stage non-permeate gas is combined with the source gas and fed to the first gas separation membrane stage. The first gas separation membrane separates that combined gas into the permeate (which is combined with the second portion as explained above) and a non-permeate. The first stage non-permeate is the second product gas mainly comprised of the second gas. The invention is particularly applicable to natural gas containing Helium.

Abstract: A polymeric membrane made of a polyimide polymer or copolymer essentially consisting of repeating units of dianhydride-derived units and diamine-derived units. At least some of the dianhydride-derived units are derived from 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane (6FDA). At least some of the diamine-derived units are derived from 2,5-diethyl-6-methyl-1,3-diamino benzene (DETDA). The balance of the diamine-derived units are derived from a diamino benzene ring with a carboxylic acid substituent.

Abstract: In a process for the separation of a stream containing carbon dioxide, water and at least one light impurity including a separation step at subambient temperature, the feed stream is compressed in a compressor comprising at least two stages to form a compressed feed stream, the compressed feed stream is purified in an adsorption unit to remove water and form a dried compressed stream, the dried compressed stream or a stream derived therefrom is cooled to a subambient temperature and separated by partial condensation and/or distillation in a separation apparatus, liquid enriched in carbon dioxide is removed from the separation apparatus, the adsorption unit is regenerated using a regeneration gas and the regeneration gas is formed by separating, by permeation in a permeation unit, the dried compressed stream or a gas derived therefrom, the permeate of the permeation unit constituting the regeneration gas.

Abstract: A process for efficiently removing carbon dioxide from a hydrocarbon containing feed stream utilizing a membrane separation unit in conjunction with a heat exchanger and a carbon dioxide separation unit wherein the streams obtained in the carbon dioxide separation unit are utilized to provide the cooling effect in the heat exchanger.

Abstract: Disclosed are methods of obtaining carbon dioxide from a CO2-containing gas mixture. The methods combine the benefits of gas membrane separation with cryogenic temperatures.

Abstract: Disclosed are methods of obtaining carbon dioxide from a CO2-containing gas mixture. The methods combine the benefits of gas membrane separation with cryogenic temperatures.

Abstract: Disclosed are methods of obtaining carbon dioxide from a CO2-containing gas mixture. The methods combine the benefits of gas membrane separation with cryogenic temperatures.

Abstract: Disclosed are methods of obtaining carbon dioxide from a CO2-containing gas mixture. The methods combine the benefits of gas membrane separation with cryogenic temperatures.

Abstract: A process for efficiently removing carbon dioxide from a hydrocarbon containing feed stream utilizing a membrane separation unit in conjunction with a heat exchanger and a carbon dioxide separation unit wherein the streams obtained in the carbon dioxide separation unit are utilized to provide the cooling effect in the heat exchanger.

Abstract: Disclosed are methods of obtaining carbon dioxide from a CO2-containing gas mixture. The methods combine the benefits of gas membrane separation with cryogenic temperatures.

Abstract: Disclosed are methods of obtaining carbon dioxide from a CO2-containing gas mixture. The methods combine the benefits of gas membrane separation with cryogenic temperatures.

Abstract: Disclosed are methods of obtaining carbon dioxide from a CO2-containing gas mixture. The methods combine the benefits of gas membrane separation with cryogenic temperatures.

Abstract: A membrane for fluid separation made of a blend of at least a polyimide polymer and a polyimidazole polymer.

Abstract: A polyimide MMC membrane useful for the production of oxygen-enriched air or nitrogen-enriched-air, for the separation of carbon dioxide from hydrocarbons or nitrogen, and the separation of helium or hydrogen from various streams. Membranes of polyimide polymers, such as polyimide polymers sold under the tradename P-84, are mixed with molecular sieve materials, such as SSZ-13, to make MMC membranes. The MMC membranes of the invention provide improved membrane performance compared to polymer only membranes, particularly when used to form asymmetric film membranes or hollow fiber membranes. The MMC films exhibit consistent permeation performance as dense film or asymmetric membranes, and do not interact with components of the process streams, such as organic solvents. The membranes of the invention exhibit particularly surprisingly good selectivity for the fluids of interest.

Abstract: A membrane for fluid separation made of a blend of at least a polyimide polymer and a polyimidazole polymer.

Abstract: A polyimide MMC membrane useful for the production of oxygen-enriched air or nitrogen-enriched-air, for the separation of carbon dioxide from hydrocarbons or nitrogen, and the separation of helium or hydrogen from various streams. Membranes of polyimide polymers, such as polyimide polymers sold under the tradename P-84, are mixed with molecular sieve materials, such as SSZ-13, to make MMC membranes. The MMC membranes of the invention provide improved membrane performance compared to polymer only membranes, particularly when used to form asymmetric film membranes or hollow fiber membranes. The MMC films exhibit consistent permeation performance as dense film or asymmetric membranes, and do not interact with components of the process streams, such as organic solvents. The membranes of the invention exhibit particularly surprisingly good selectivity for the fluids of interest.

Abstract: Xe exhaled from a patient is recovered with a polymeric membrane.

Abstract: A polyimide MMC membrane useful for the production of oxygen-enriched air or nitrogen-enriched-air, for the separation of carbon dioxide from hydrocarbons or nitrogen, and the separation of helium or hydrogen from various streams. Membranes of polyimide polymers, such as polyimide polymers sold under the tradename P-84, are mixed with molecular sieve materials, such as SSZ-13, to make MMC membranes. The MMC membranes of the invention provide improved membrane performance compared to polymer only membranes, particularly when used to form asymmetric film membranes or hollow fiber membranes. The MMC films exhibit consistent permeation performance as dense film or asymmetric membranes, and do not interact with components of the process streams, such as organic solvents. The membranes of the invention exhibit particularly surprisingly good selectivity for the fluids of interest.

Abstract: Mixed matrix composite (MMC) membranes with minimal macrovoids and defects are provided by the current invention. MMC Membranes are needed that have minimal macrovoids and defects, provide consistent and good selectivity and permeability performance, provide the mechanical strength required to withstand high membrane differential pressures, and exhibit sufficient flexibility and can easily be formed into desirable membrane forms. MMC Membranes made from a spinning dope that is stabilized with an electrostabilizing additive, particularly an acid additive, results in membranes, particularly hollow fiber membranes that have minimal macrovoids and defects. Thus, membranes of the current invention are particularly suitable for high trans-membrane pressure applications, particularly for separating oxygen/nitrogen, hydrogen/hydrocarbon, and carbon dioxide/hydrocarbon components of a stream.