PROCESS FOR THE PRODUCTION OF ETHANOL AND SOLVENTS FROM LIGNOCELLULOSIC BIOMASS WITH RECYCLING OF AN ETHANOLIC LIQUOR OBTAINED FROM THE FERMENTATION OF PENTOSES

摘要

The present invention describes a process for production of alcohols and/or solvents from a cellulosic or lignocellulosic biomass, comprising: a step for thermochemical pre-treatment of a cellulosic or lignocellulosic substrate; an optional step for washing the pre-treated substrate and adjusting the pH; a step for enzymatic hydrolysis of the pre-treated substrate; a step for ethanolic fermentation of the hexoses contained in the hydrolysate obtained from step (c) into ethanol by a hexose-fermenting microorganism and for obtaining an ex-hexose ethanolic liquor; an extraction step; a step for ethanolic fermentation of the pentoses contained in at least one of the streams obtained from one of the preceding steps with a pentose-fermenting microorganism and for obtaining an ex-pentose ethanolic liquor; in which at least a portion of the ex-pentose ethanolic liquor is recycled upstream of at least one of the enzymatic hydrolysis and/or ethanolic fermentation steps.