The main advantage
of the lowconcentration acid in the hydrolysis
process is that acid recovery may not be required
and there will be no signi0cant losses of acid. However,
in a lowconcentrated acid process, the reaction
should be carried out at high temperature and pressure,
and due to poor yields of glucose from cellulose
in the hydrolysis step the ethanol yield is low. Due to
near-quantitative yield of glucose from cellulose, the
use of high concentration acid in the hydrolysis process
may yield higher quantities of ethanol but di4erent
vessels and a good acid recovery process will be
required