Patent ID: 7294174
Filing Date: 2007-11-13
Classification: B01D

Abstract:
1. An air dehydration membrane comprising a hydrophilic polymer having a permeability for water vapor which is greater than its permeability for air, said hydrophilic polymer also showing low selectivity between oxygen and nitrogen, the polymer having a hydrophilic coating, wherein the coating is chosen such that 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, wherein the membrane in an uncoated condition has a permeability for air in a range of about 2.5-20×10 −4 cm 3 /cm 2 ·sec·cmHg, and wherein the membrane is selected such that a dominant mechanism for gas flow through the membrane is Knudsen flow.