The maximum conversion by sulfuric acid was
about 60.7%. It did not enhance reducing sugar
yields when concentration of sulfuric acid was
increased. Weak acid, acetic acid, exhibited low
reactivities under the identical hydrolysis conditions
(Fig.1). The reduced reducing sugar concentrations
likely resulted from the degradation to degraded
products such as furfural. Compared to glucose,
xylose is more sensitive to degradation to furfurals,
particularly at acid concentrations over 1% and
reaction temperatures higher than 120°C