Membrane process for organic vapor recovery from air

Abstract

New organic vapor separation membrane has been developed. Air containing a relatively high organic vapor concentration is fed to the membrane and the organic vapor is selectively extracted. The organic vapor separation membrane is a composite membrane. It consists of a thin skin layer and a porous support layer and nonwoven polyester backing. The skin layer is the selective barrier layer composed of three dimensionally crosslinked elastomeric polymer. Polyimide which has a high resistance to solvents is used for the porous support layer. The composite membrane has an organic vapor permeation rate of 5–20 Nm3/m2hratm, depending on the types of the organic vapors. The permeation rate shows good correlation with the boiling point of the organic vapors. Spiral module type is used for actual application. Vapor concentration after treatment of the module is changed significantly depend on the vapor pressure ratio and flow rate difference between feed side and permeate side of the module. © 1991 The Society of Polymer Science, Japan. All Rights Reserved.