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.

Abstract: This abstract discusses producing mixed matrix composite (MMC) membranes using polyimide polymers. Polyimide MMC membranes of the current invention are particularly 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 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. The MMC films exhibit consistent permeation performance as dense film or asymmetric film 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: This abstract discusses producing mixed matrix composite (MMC) membranes with a good balance of permeability and selectivity. MMC membranes are particularly needed for separating fluids in oxygen/nitrogen separation processes, processes for removing carbon dioxide from hydrocarbons or nitrogen, and the separation of hydrogen from petrochemical and oil refining streams. MMC Membranes made using washed sieve material, such as washed SSZ-13 sieve material, provide surprisingly good permeability and selectivity. The method of the current invention produces a fluid separation membrane by providing a polymer and a washed molecular sieve material, then synthesizing a concentrated suspension of a solvent, the polymer, and the washed molecular sieve material. The concentrated suspension is used to form the fluid separation membrane of the desired configuration. Membranes of the current invention can be formed into hollow fiber membranes that are particularly suitable for high trans-membrane pressure applications.

Abstract: A food conditioning chest has a generally rectangular tub supported in the housing to define an upwardly opening food well for supporting foodstuffs. Louvered openings are formed in opposite end walls and the front wall and the rear wall of the tub. A return duct communicates with the food well through the openings formed in the end walls and transports return air to an intake chamber formed beneath the tub floor. An intake duct extends from the intake chamber and communicates with the food well through the openings formed in the front wall and the rear wall. A centrifugal fan positioned in the intake chamber circulates air from the return duct and the intake duct. As the air flows through the intake chamber, it passes over at least one heating element which heats the air to a desired temperature.