Abstract: An air dehydration membrane is made of a hydrophilic polymer having a permeability for water vapor which is greater than its permeability for air, and having low selectivity between oxygen and nitrogen. The membrane has a hydrophilic coating, which itself may be a polymer. The coating does not affect the selectivity of the coated membrane with respect to oxygen and nitrogen, but does increase selectivity of the membrane with respect to water vapor. A preferred material for the membrane is polysulfone. Preferred materials for the coating are poly vinyl alcohol and Triton X-100. The membrane is selected such that the dominant mechanism for gas flow through the membrane is Knudsen flow. The membranes are made at low cost, and can outperform existing commercial membranes in either volumetric productivity or product recovery.

Abstract: A system and method for separating air into components uses an air dehydration membrane for removing water vapor from compressed air. Dried compressed air is then directed, from the dehydration membrane, into a gas separation module which may be a membrane system, different from the air dehydration membrane, or a pressure swing adsorption (PSA) system. The air dehydration membrane is made of a hydrophilic polymer having a permeability for water vapor which is greater than its permeability for air, and having low selectivity between oxygen and nitrogen. The air dehydration membrane has a hydrophilic coating, which itself may be a polymer. The coating does not affect the selectivity of the coated dehydration membrane with respect to oxygen and nitrogen, but does increase selectivity of the membrane with respect to water vapor.

Abstract: An air dehydration membrane is made of a hydrophilic polymer having a permeability for water vapor which is greater than its permeability for air, and having low selectivity between oxygen and nitrogen. The membrane has a hydrophilic coating, which itself may be a polymer. The coating does not affect the selectivity of the coated membrane with respect to oxygen and nitrogen, but does increase selectivity of the membrane with respect to water vapor. Preferred materials for the membrane are polysulfone and poly ether sulfone. Preferred materials for the coating are poly vinyl alcohol and Triton X-100. The membranes are made at low cost, and can outperform existing commercial membranes in either volumetric productivity or product recovery.

Abstract: A boreside feed gas separation membrane device containing primarily hollow fiber membranes with discrete flow channels incorporated into the bundle to allow for pressure removal of the permeate gas collected on the shellside of the device is described. The flow channels minimize pressure drop and/or the build-up of back pressure on the shellside of the device while maintaining proper counter-current flow patterns in the device. The incorporation of flow channels results in improved efficiency of the device, especially for feed streams or membrane types that lead to high permeate flow rate that result in excessive shellside pressure drops.