Pre-hydrolysis was carried out in an electrically heated digester
of 5 L capacity. The digester was rotated at 1 rpm. Water prehydrolysis
was carried out at 150, 160 and 170 ◦C for 60, 90
and 120 min. The raw material to liquor ratio was 1:5 (g/mL).
The time required to raise max temperature from room temperature
(30 ◦C) was 35 min. After completing pre-hydrolysis, pressure
was released by venting the valve and the liquor was separated
from the solid mass by filtration and kept in refrigerator for
analysis.