Semi-continuous fuel ethanol production (FEP), based on the utilization of potato overstocks, including either acid (process I) or enzymatic (process II) hydrolysis of potato starch on the industrial scale was developed. The FEP simulations were developed by help of the Aspen Plus (R) software using both experimental and literature data. The main goals were to analyze the influence of starch conversion kinetics on overall process design, to compare two FEP processes with respect to their technical benefits and limitations, to use the mass and energy balances for determining the consumption of materials and energy and to evaluate FEP environmental impact. From the technical assessment, both processes were shown to be feasible for producing high quality fuel ethanol. The analysis showed that the process I was less complex since it required fewest and smallest process equipment units than the process II, making it a competitive alternative for commercial FEP form potato overstocks. (C) 2010 Elsevier Ltd. All rights reserved.