Polyazole polymers membranes for high pressure gas separation technology

Abstract

Aromatic (fluorinated and non-fluorinated) polyoxadiazole and polytriazole polymers were synthesized through one step polycondensation method in the lab followed by gas permeation and purification performance of the membranes prepared by casting their polymer solution from chloroform or NMP solvents. The gas permeability and selectivity values were found mainly depending on the bulky fluorinated groups (hexafluoroisopropylidene, HFA) on the main polymer stem and a bulky aniline derivatives (4-bromoaniline & 4-aminophenol) groups as a side chain of the polymer stem. No plasticization effect was observed for the membranes under a high range of pure CO2 feed pressure (100–800 psi). The polymers synthesis process is simple and reproducible, easy solubility in most of the common organic solvents and easily scalable for commercial production. The polymer membrane materials developed in this research work, showed a considerable high permeability for CO2 and helium gases and a very low or negligible permeability for other gases such as methane (CH4), nitrogen (N2) and ethane (C2H6) at a very high operating feed pressure (up to 800 psi). Based on the preliminary results, these polymers membranes can be considered as promising materials for gas separation technology especially for helium recovery and CO2 gas removal with a high selectivity. This work represents the testing of dense membranes under different experimental conditions of feed pressure (up to 800 PSI) at room temperature to investigate their mechanical and chemical stability for potential industrial application.