Modeling and kinetic study of bio-ethanol production from soy protein concentrate by-product

The aim of this work was to evaluate a non-agitated process of bioethanol production from soybean molasses and the kinetic parameters of fermentation using a strain of Saccharomyces cerevisiae (ATCC. 2345). Kinetic experiment was conducted in medium with 30% (w v(-1)) of soluble solids without supplementation or pH adjustment. The maximum ethanol concentration was in 44 hours, the ethanol productivity was 0.946 g L-1 h(-1), the yield over total initial sugars (Y-1) was 47.87%, over consumed sugars (Y-2) was 88.08% and specific cells production rate was 0.006 h(-1). The mathematical polynomial was adjusted to the experimental data and provided very similar parameters of yield and productivity. Based in this study, for one ton of soybean molasses can be produced 103 kg of anhydrous bioethanol.