Effect of Cartapip97® pretreatment on the kraft pulping of Radiata pine

Improved uniformity during kraft pulping can lead to greater pulp quality and reduced operating costs. Uniform chip impregnation with pulping liquor ar the beginning of kraft pulping has a major effect on overall uniformity. In this regard hydrophobic wood extractives are known to impede homogeneous penetration of pulping liquor into chips. Thus new methods which minimise this impediment are likely ro improve the kraft process. It has been reported that pretreatment of wood chips with extractive-degrading fungus can achieve this aim (1). The present study assessed the response of radiata pine to pretreatment with such a fungus, ie. Ophiostoma piliferum which is marketed as Cartapip 97(R) Ophiostoma piliferum was applied to radiata pine chips for 21 days, then chips were analysed for changes in extractive composition and kraft pulped in the laboratory. Pretreatment with Ophiostoma piliferum for 21 days substantially reduced the dichloromethane (DCM) extractives in radiata pine chips. For example, chips treated with Ophiostoma piliferum grown on Peptone medium contained 53% less DCM extractives than similarly aged control chips. Reductions in individual classes of extractives were about 40% for triglycerides, 40% for steryl esters, 30% for fatty acids and sterols and 70% for resin acids. Unfortunately this had little effect on kraft pulping we or selectivity. Some reduction in pulp rejects was. however. indicated. Any benefits from the reduction of extractives by Ophiostoma piliferum treatment may be realised in other areas of pulp and paper production, such as in improved pitch control or enhanced wet end performance.