Model based analysis of plasticization behaviour of polymeric membranes used for high pressure CO₂ separation in natural gas processing

Plasticization resistant property is very important in measuring the performance of polymer membranes for high pressure CO₂ separation from natural gas or separation in aggressive environment. Many polymeric membranes have been synthesized and tested for high pressure CO₂ separation. Thus, a quick qualitative comparison will be necessary in the early phases of a membrane gas separator design to facilitate material selection. In this paper, we developed a procedure that integrates experimental and mathematical models to determine the plasticization pressure from permeability measurement data. This procedure permits the use of a graphical method for membrane materials selection for high pressure operations. It was demonstrated that the plasticization behaviour of the current generation of plasticization resistant polymer membranes can be approximately described by a quadratic (2nd order) empirical equation. A theoretical justification was proposed to support this idea. The model was tested on more than ninety polymer membrane samples and results correlate well with experimental results that have been reported in the literature.