Modification of loblolly pine chips with Ceriporiopsis subvermispora part 2: Kraft pulping of treated chips

Loblolly pine (Pinus taeda) chips treated with Ceriporiopsis subvermispora for two or four weeks were pulped with different combinations of kraft pulping conditions to obtain a better understanding of the interaction between the fungal action and the pulping variables. Two different levels of effective alkali (18 or 22%), two times at maximum T_max (60 or 90 min), 22% sulfidity, and a T_max of 170°C, were used. The best delignification without adversely affecting pulp viscosity was found in pulps made from chips treated with the fungus for 2 weeks and at the mildest pulping conditions. At all pulping conditions there was a substantial decrease in the amount of rejects with 2 weeks of fungal treatment. Pulps from fungally-treated chips refined more easily than the control pulp and strength properties of pulps of fungally-treated chips were superior to those of the control pulp.