Modeling of Industrial Psa Process for Fuel Ethanol Production

Dehydration of ethanol via adsorption on 3Å molecular sieves has recently been increasing in application in industry as an alternative to the conventional separation techniques for breaking the ethanol-water azeotrope. Over the past 20 years, Pressure-Vacuum Swing Adsorption (PSA) processes have gained increasing commercial acceptance as an energy-efficient separation technique. A general purpose package for simulation of cyclic adsorption processes based on the data from an operating plant and laboratory data has been developed. The dispersed plug flow model includes variation of axial velocity and the fluid flow follows Ergun‘s equation locally. A linear driving force mass-transferrate coefficient was used to describe adsorption and desorption kinetics. The operation of the column can be isothermal, adiabatic or non-isothermal non-adiabatic. The governing parabolic equations have been solved via method of lines using a stiff equation integration package. Several case study simulation results of dewatering the ethanol-water mixture in the fuel ethanol production process are presented.