Influence of the Membrane Mass Transfer Properties Study Technique on the Process Simulation Results

Abstract

The presented work is aimed at studying the gas transport characteristics of polymeric hollow-fibre gas separation membranes. Such materials as: polysulfone (PSF), polyphenylene oxide (PFO), polyetherimide (PEI), polyetherimide with polyimide (PEI+PI) were studied on the example of air mixture separation. The values of the permeances of pure gases O2 and N2 and the mixed permeances of oxygen and nitrogen during air separation were obtained. Mathematical models of the gas separation process built on the basis of these values show significant discrepancies. To obtain a gas mixture with 95 mol.% nitrogen from air, taking into account the mixture permeance, 15.8% more PSF membrane area is required than taking into account the permeance of pure gases. For a PPO membrane this value is 13.9%, for PEI 19.8% less area is required, and for PEI+PI 15.9% less. In the design of industrial or semi-industrial membrane installations, such discrepancies can lead to significant errors, including technical and economic ones.