Transport of CO2/CH4 through PEBA membranes: experiments and mass transfer modelling

This work presents a study of the CO2 transport process in Block Polyether Amide (PEBA) membranes, based on an experimental design and mathematical modelling, considering a fickian and non-fickian diffusion models. PEBA membranes were synthesized using the plate casting method and were thermally characterized by differential scanning calorimetry and thermogravimetric analysis. Subsequently, experimental measurements of the concentration of permeated gases were carried out, using different pressure and temperature conditions for a fixed CO2/CH4 mixture. The permeability, selectivity, diffusivity, and solubility of CO2 were determined. It was found that the membranes are highly selective to CO2 over the CH4. The experimental data of the permeated CO2 concentration throughout the operating time, the solubility and diffusivity were employed in the mathematical models to describe the solution- diffusion phenomenon. It was found that the fickian model was only able to reproduce the behaviour of the process at the steady state conditions. In contrast, the non-fickian model achieved an appropriate description of the process.