Mid Sweden University

This laboratory research was undertaken to gain a better understanding of Acacia mangium and Eucalyptus pellita and their feasibility as feedstock in acid sulfite pulping. The plantation-grown hardwood chip samples were obtained from Sabah, Malaysia. The wood samples were analyzed for carbohydrates, lignin and extractives. The cooking experiments were carried out in 2L autoclaves with temperatures of 130°C and 140°C, with varied chemical charges, after which the resulting pulp samples were characterized for kappa number and fiber quality. The results revealed that a cooking temperature of 140°C was needed to reach kappa numbers below 30, but this also resulted in much reduced fiber length and higher fines content than 130°C, probably due to the intensified acid hydrolysis. To reach kappa numbers below 20, even more severe cooking conditions would be needed. This kind of pulp and the resulting lignin may be well used as intermediate products in biorefineries.