Kraft biopulping of Eucalyptus grandis

[摘要] ENGLISH SUMMARY: Biotechnology has been earmarked as the field that will shape the future of the worldas we know it and its advance has not excluded the pulp and paper industry. Theimportance of biotechnology in the paper industry is emphasized by the large amountof research that has been performed in the various fields of its application ranging frombiopulping, biobleaching to deinking technology. However, biopulping research hasfocused on biomechanical pulping, while little attention has been placed on chemical .pulping methods and the advantages derived from fungal pre-treatment. Therefore, theeffect ofthe pretreatment of Eucalyptus grandis wood chips, with white-rot fungi, on theKraft pulping process was investigated. Eucalyptus grandis is the predominanthardwood species used in the pulp and paper industry of South Africa. Initially ascreening program was performed in order to evaluate the biopulping potential of 100different fungal cultures, isolated in South Africa. Wood chips were inoculated withselected fungal cultures and incubated for a two-week period, at the relevant optimumgrowth temperatures, under aseptic conditions. Bio-degraded wood chips were pulpedby means of the Kraft pulping process and the resultant pulp and black liquor wereanalysed for yield, shives, kappa number and residual active alkali. Twelve cultures,which showed the most potential for biopulping, were selected from the screeningprogram for further evaluation and statistical validation. Results indicate that certainselected cultures affect significant improvements in the residual active alkali of justunder 21%, while the kappa number was reduced by just less than 9%. Under theprevailing conditions, the chemical consumption decreased significantly by ca. 2%. Nosignificant differences, between the test cultures and the control, were observed foryield and shive content. These results prove conclusively that Kraft biopulping ofEucalyptus grandis wood chips has a significantly positive effect on the pulp producedby this process~The-itnplication of savings in both pulping and bleaching chemicals areenormous. It is strongly suggested that a mill-scale trial be performed, upon which afull investigation into the financial implications of Biokraft pulping should be determined.

[发布机构] Stellenbosch University