A Kinetic Study of Ethanol Fermentation from Paulownia elongata Wood Extract Hydrolysate with Supplemented Glucose by Saccharomyces cerevisiae and Xylose Recovery from Fermentation Medium

Ethanol is a clean and renewable biofuel that is considered to be a good alternative to gasoline. Bioethanol can be produced from simple sugars, starches, and lignocellulosic materials. Ethanol from lignocellulosic biomass does not affect food or feed industry. This research investigated the ethanol production, cell growth, and sugar utilization from using Paulownia elongata wood extract hydrolysate by the Baker's yeast Saccharomyces cerevisiae. The highest ethanol concentration 15.5g/L was achieved at 15h fermentation by consuming glucose, mannose, and galactose with the ethanol yield 0.419g/g sugar. Monod equation was used to do the kinetic modeling of the fermentation process. It described the fermentation processes of using glucose and mannose (0-7h) and consuming galactose (10-15h) well. The unused xylose was recovered from the fermentation medium through vacuum evaporation and the estimate xylose yield was 20% (w/w).