The demand for pure ethanol has become paramount for its various applications in biofuels and preparation of industrial chemicals, food and pharmaceutical products. Pressure Swing Adsorption (PSA) has proven to be an effective process and a more economical method for separating the azeotropic concentration of ethanol-water (95% ethanol, 5% water) than distillation. The modeling of PSA of ethanol-water azeotropic concentration on zeolite 3A was done. The unsteady state mass balance equation for the water molecule in the packed bed was obtained. The sets of Partial Differential Equations obtained from the model equations were solved with the Crank Nicholson finite difference method using MATLAB software. The simulated data was observed to be considerably in agreement with the experimental data. The data obtained for dimensionless bed length z=0.1 explains better the experimental result with Least Sum of Square Error (LSSR) of 0.06588. Breakthrough time of 600sec was obtained from simulated data while that of experimental was 680sec. The purity of 99.2705% v/v anhydrous ethanol was obtained.

Keywords: Biofuel, azeotropic concentration, pressure swing adsorption, breakthrough time