Production of bio-ethanol from soybean molasses by Saccharomyces cerevisiae at laboratory, pilot and industrial scales

Abstract

The aim of this work was to develop an economical bioprocess to produce the bio-ethanol from soybean molasses at laboratory, pilot and industrial scales. A strain of Saccharomyces cerevisiae (LPB-SC) was selected and fermentation conditions were defined at the laboratory scale, which included the medium with Soluble solids concentration of 30% (w/v), without pH adjustment or supplementation with the mineral sources. The kinetic parameters - ethanol productivity of 8.08 g/L h, Y(P/S) 45.4%, Y(X/S) 0.815%. m 0.27 h(-1) and mu(x) 0.0189 h(-1) - were determined in a bench scale bioreactor. Ethanol production yields after the scale-up were satisfactory, with small decreases from 169.8 L at the laboratory scale to 163.6 and 162.7 L of absolute ethanol per ton of dry molasses, obtained at pilot and industrial scales, respectively.