Evaluation of Different Enzymes and Yeasts, and Their Impact on Bioethanol Production Based on Debranned Wheat

Abstract: Bioethanol is a fuel of tomorrow, and progress in the use of enzymes and reduction of non-fermentable materials by debranning will probably be a part to make it more economical with low environmental impact.   Ethanol production based on debranned wheat was optimized in this study by batch experiments as well as continuous experiments in laboratory scale. Enzymes from Novozymes and Genencor were compared and no significant differences were discovered between the different set of enzymes. The yeast strains Ethanol Red and AmyloFerm were compared with traditional baker’s yeast and baker’s yeast were surprisingly the fastest to ferment, but Ethanol Red had higher viability during fermentation. Protease addition during saccharification does not seem to improve fermentation with baker’s yeast. Prolonged liquefaction and saccharification time does probably not have any large impact on glucose yield. The continuous lab-scale process has a potential to be a realistic model but the stirring has to be improved and the pipe diameter increased.