Hot-water extraction and soda pulping of bagasse

Bagasse was subjected to hot-water extraction (or prehydrolsis) at 160°C for 30 minutes, which resulted in about 15% mass-removal. Compared to the untreated bagasse, alkali charge of prehydrolyzed bagasse cooking can reduce from 18.9% to 16.0%, while the kappa number of the resultant pulp reduce from 13.1 to 11.0 and pulp viscosity increases. ECF bleaching process was applied to the pulps produced from prehydrolyzed bagasse and untreated bagasse. At the same kappa factor, prehydrolysis of bagasse can reduce ClO₂ demand by almost 20% while the brightness of the bleached pulp increases significantly. Bagasse prehydrolysis or hot-water extraction before soda pulping can reduce effluent discharge and reduce chemical demand.