Water Removal from Ethanol Vapor by Adsorption on Canola Meal after Protein Extraction

In this paper, biosorbents based on canola meal obtained after protein extraction were developed to adsorb water from ethanol–water vapor mixture in a pressure swing adsorption (PSA) process. It was demonstrated that through the process over 99 wt % fuel grade ethanol was achieved from lower grade feeds containing 80–95 wt % ethanol at 90–110 °C and 136–243 kPa. The breakthrough curve technique was used to investigate the adsorption dynamics and equilibrium. The effects of temperature, pressure, vapor feed concentration, and adsorbent particle size on water and ethanol uptake and separation factor were examined. External water mass transfer coefficients were also calculated. The model based on Dubinin–Polanyi potential theory fit the water adsorption isotherms reasonably well. The mean free energy of water adsorption was calculated to be 0.04 kJ/mol, and heat of adsorption was −35.81 kJ/mol, which indicated the physical nature of the adsorption. Water saturated canola meal biosorbents were regenerated at 90 °C under vacuum and reused