抄録
It is important to produce bioethanol from cellulosic biomass, which doesn’t compete with food. Ethanol production process
from cellulosic biomass is classified by many pretreatment and saccharification methods. This study considers three methods
that are using concentrated sulfuric acid hydrolysis (NEDO), dilute sulfuric acid pretreatment and enzyme saccharification
(NREL), and hot water and milling pretreatment and enzyme saccharification (AIST). Three processes are designed by process
simulator PRO/Ⅱ, and these material and energy balances are calculated. Conversion efficiencies of saccharification and
fermentation are sensitive for ethanol production system, so the range of efficiency values is considered. Finally, these
processes are evaluated by amount of CO2 emission reduction. NEDO process needs a large amount of thermal energy for
sulfuric acid recovery, and AIST process uses a lot of power for disk milling. NREL process achieves the highest CO2 emission
reduction. In the case of no byproduct (mainly lignin) use, however, all processes has a potential to be not able to reduce CO2
emission. In order to reduce CO2 emission, it is essential to use byproduct for process energy supply.
