METHOD FOR PRODUCING ETHANOL FROM LIGNOCELLULOSIC BIOMASS AND PRETREATMENT METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a pretreatment method for efficiently removing lignin, also improving the sugar yield, and to provide a production method for ethanol (bioethanol), using lignocellulosic biomass as the raw material and performing saccharification of hemicellulose and cellulose by an enzymic method.SOLUTION: The pretreatment method removes lignin from the lignocellulosic biomass by digestion of the lignocellulose biomass, using an aqueous ethanol solution of a metal hydroxide, and heat treatment. From the used digestion solution, the ethanol and the metal hydroxide are recovered to be reused. In the aqueous ethanol solution of the digestion solution, the metal hydroxide concentration is preferably 0.1 mol/L and 4.5 mol/L. Likewise, the ethanol concentration is preferably 10 vol.% and 75 vol.%.