(117d) Modeling of Industrial Psa Process for Fuel Ethanol Production

In the production process, ethanol from fermentation is concentrated in distillation columns. The azeotrope is formed in water-ethanol mixture at high ethanol concentration and thus the final purification of ethanol is done by pressure swing adsorption (PSA) using hydrophilic zeolite. A simulation package for the PSA process, based on the data from an operating plant has been developed. Adiabatic dispersed plug flow model includes variation of axial velocity and pressure drop. Adsorption equilibrium data were provided by adsorbent manufacturer. Linear driving force mass transfer rate coefficient as a function of local values of temperature and concentration was used to describe adsorption and desorption kinetics. The set of degenerated parabolic equations has been solved by a high order approximation scheme and the resulting system of stiff differential equations has been integrated by the Hindmarsh routine. The model has been used to improve the operating conditions in the plant. Several case studies of the simulation results will be discussed.