INFLUENCE OF ULTRA LOW AND HIGH TEMPERATURE ON ENZYMATIC PRETREATMENT OF BEECH BRANCHES WOOD

Abstract

The publication is focused on the effect of ultra low and high temperature on enzymatic pretreatment of beech wood (Fagus sylvaticaL.). Two fractions < 0.7 mm and 1.0 –2.5 mm of disintegrated branches sawdust were used for experiments. Glucose and xylose yields were measured after 24, 48, and 72 hours of enzymatic hydrolysis with 15 % load of the enzyme measured to total cellulose content. The influence of freezing under -80°C and boiling under pressure at +160°C on samples before enzymatic hydrolysis was observed. Mutual combination of boiling under pressure to obtain the maximum water uptake and subsequent freezing was used to better understand the process of cell destruction. The results show that the boiling pretreatment has a positive influence on thetotal monosaccharide yields and the subsequent freezing may slightly increase these yields even further. The maximum monosaccharide conversion (73.24%) was achieved using the fraction < 0.7 mm.