PRETREATMENT OF BAGASSE BY ALKALI-OXYGEN

Abstract

For the enzymatic hydrolysis, the effect of the pretreatment of delignification by alkali-oxygen oxidation has been studied. The extent of delignification by the pretreatment at various conditions and the digestibility by enzyme were measured to estimate the effect.
With the progress of delignification, the digestibility increased. After pretreatment at 80°C with 1.5-2% or 60°C with 3% sodium hydroxide at 5kg/cm² G initial oxygen pressure, the extent of delignification was about 80% and the digestibility reached to 90% from 20% for the unpretreated sample.
Based on the sugar analysis, it was shown that 50mg/ml of total reducing sugars corresponding to weight loss during the hydrolysis was formed.
The delignification in excess made no contribution to improve the digestibility by enzyme and this was disadvantage from the viewpoint of the yield of bagasse.
When the pretreatment was carried out by the initial oxygen pressure of 2 or 0kg/cm² G, both of the delignification and the digestibility by enzyme were not so changed. This indicates that so high pressure is not necessary for the pretreatment.