| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an ethanol production method using cellulosic biomass as a raw material, in which saccharification/decomposition efficiency is improved and besides, a cost of a saccharification/decomposition process is suppressed.SOLUTION: The ethanol production method using cellulosic biomass as a raw material comprises: a first saccharification/decomposition step of performing hot water treatment on slurry of cellulosic biomass, whose pH is adjusted to 1.0 or more and 3.5 or less by strong acid, in a supercritical state or a subcritical state, and performing saccharification/decomposition on cellulosic biomass into C5 monosaccharide; a first solid-liquid separation step of performing solid-liquid separation on the slurry after the first saccharification/decomposition step; a second saccharification/decomposition step in which a dehydrated cake obtained in the first solid-liquid separation step is pressurized until it becomes a supercritical state or a subcritical state, and saccharification/decomposition is performed on cellulose contained in the cellulosic biomass into C6 monosaccharide; a second solid-liquid separation step of performing solid-liquid separation on the slurry after the second saccharification/decomposition step; a fermentation step of performing alcohol fermentation on saccharified solution obtained in the first solid-liquid separation step and the second solid-liquid separation step; and a distillation step of distilling the obtained fermentation liquid to concentrate ethanol.</p> |
