Study on biomechanical pulping of fast-growing woods - I. Fungal pretreatment of mechanical pulp of Paulownia elongate

This paper deals with the pretreatment of Paulownia elongate wood chips with three strains of fungi (Phanerochaete chrysosporium ME 446 and its mutant LIP-14, and a commercial fungus Ophistoma piliferum) and the effects of fungal pretreatment on the chips chemical components, refining energy consumption and pulp strength. The research results showed: (1) After the pretreat ment with LIP-14 and ME 446, the chip weight loss was 4.31% similar to 5.42%, 19.6% similar to 21.6% of which was lignin loss. As the chips were treated with O.P., hot water extractives and benzene-alcohol extractives were reduced 33.1% and 12.1%, respectively. (2) Three fungal treatments at 55 degrees SR beating degree saved 13.2% similar to 22.4% energy with 7.9% similar to 30%, 15.2% similar to 88% and 3.8% similar to 12% increases in break, burst and. tear indexes, separately. However, the brightness and light scattering coefficient were reduced 3% similar to 4% ISO and 10% similar to 14.6%, and little effect on opacity. Based on the results of both energy savings and strength property improvement, LIP-14 was the most promise fungus for use in biomechanical pulping of Paulownia elongate chips, O.P. the second and ME 446 the last.