Different lignocellulosic
sawdust was mixed with 60% sulfuric acid treated in
a water bath with a temperature of 60 C for 30 min at the first
stage hydrolysis and subsequently subjected to 30% sulfuric acid
at 80 C for 60 min at the second stage. After reaction was completed,
solids were separated from the hydrolysate (aqueous solution)
by filtration