EFFECT OF ENZYME PRETREATMENTS ON CONVENTIONAL KRAFT PULPING

Sycamore chips were pretreated using a cellulase/hemicellulase mixture prior to conventional kraft pulping. Treatment conditions were 24 hou rs at 50 degrees C, pH 5, and a cellulase/hemiocellulase solution at 5 filter paper units (mmols of reducing sugar per milliliter) per gram ovendry wood. After enzyme pretreatment followed by kraft pulping, the kappa number of the control was as much as 10% higher than that of th e treated chips. In addition, enzyme-treated pulps required less ClO2 per ton pulp (approximate to 20 lb ClO2) than the control. Pulp streng th properties for the pre-treated chips were comparable to kraft pulps receiving no enzyme pretreatments. Pulp viscosity was lower in pulps treated with cellulase/hemicellulase alone.