Modelling of organic-solvent flux through a polyimide membrane

The tremendous experimental effort to find a suitable organic solvent nanofiltration (OSN) membrane for a specific separation problem can be minimised by using model-based simulation tools to predict organic-solvents fluxes. A new predictive model, based on the Maxwell–Stefan (MS) approach, for prediction of fluxes through dense polymeric OSN membranes was developed to aid the experimental effort. Model parameters were determined from independent experiments to model solubilities and diffusivities. The flux measurements were performed using a cross-flow nanofiltration filtration unit LSta60LM (SIMA-tec) and the OSN membrane STARMEM240™. The calculated organic-solvents fluxes of toluene, ethyl acetate, ethanol, and 2-propanol show an excellent agreement with the measured fluxes at 25 °C and different transmembrane pressures.