MEMBRANE APPLICATIONS FOR GAS CLEANUP AND GAS SEPARATION HAVE BEEN LIMITED BECAUSE OF THEIR LOW FLUX, THE CHEMICAL RESISTANCE OF CURRENT MATERIALS, AND BECAUSE OF THEIR HIGH TEMPERATURE LIMITS.

MEMBRANE APPLICATIONS FOR GAS CLEANUP AND GAS SEPARATION HAVE BEEN LIMITED BECAUSE OF THEIR LOW FLUX, THE CHEMICAL RESISTANCE OF CURRENT MATERIALS, AND BECAUSE OF THEIR HIGH TEMPERATURE LIMITS. MEMBRANE PERMEATION RATE IS A FUNCTION OF THE CHEMICAL POTENTIAL DIFFERENCE ACROSS THE MEMBRANE ANDTHE PATH LENGTH. CORROSIVE MATERIALS SUCH AS FLUE EMISSIONS, SYNTHESIS GAS, AND HYDROGEN SULFIDE CREATE DIFFICULT ENVIRONMENTS FOR CURRENT MEMBRANE MATERIALS. ELEVATED TEMPERATURE EFFICIENCIES INCREASE THE PROBLEMS ASSOCIATED WITH CORROSIVE ENVIRONMENTS. FLUX RATES (AND HENCE ECONOMICS) ARE DETERMINED BY MEMBRANE THICKNESS. MOSTMATERIALS WHEN PREPARED AS THIN FILMS, ARE DIFFICULT TO HANDLE AND DO NOT HAVE THE TENSILE STRENGTH DESIRED FOR PRACTICAL APPLICATIONS. A NEW MATERIAL IS AVAILABLE WHICH OVERCOME MANY OF THESE LIMITATIONS. POLYPARAPHENVLENCE BENZOBISTHIAZOLE (PBT) HAS BEEN DEVELOPED AS A HIGH TEMPERATURE STRUCTURAL MATERIAL FOR AEROSPACE APPLICATIONS. SINCE IT IS A LIQUID CRYSTALLINE POLYMER, IT HAS VERY HIGH TENSILE STRENGTH, VERY GOOD HIGH TEMPERATURE PROPERTIES, ANDEXCELLENT CHEMICAL INERTNESS. IT APPEARS TO BE A VERY DESIRABLE CANDIDATE FOR ELEVATED TEMPERATURE GAS SEPARATIONS IN CORROSIVE ENVIRONMENTS. A PROCESS HAS BEEN DEVELOPED FOR PRODUCING MICROPOROUS FILM FROM PBT DOPE. PHASE I OF THIS PROGRAM WILL DEVELOP THE MEMBRANE PROPERTIESNEEDED FOR GAS AND LIQUID SEPARATIONS.