Masters Degrees (Forest and Wood Science)

Permanent URI for this collection

https://scholar.sun.ac.za/handle/10019.1/546

Browse

Browsing Masters Degrees (Forest and Wood Science) by Author "Cerff, Craig Bradley"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Kraft biopulping of Eucalyptus grandis
    (Stellenbosch : Stellenbosch University, 1999-12) Cerff, Craig Bradley; Gerischer, G. F. R.; Janse, B. J. H.; Stellenbosch University. Faculty of Faculty of AgriSciences. Dept. of Forest & Wood Science.
    ENGLISH SUMMARY: Biotechnology has been earmarked as the field that will shape the future of the world as we know it and its advance has not excluded the pulp and paper industry. The importance of biotechnology in the paper industry is emphasized by the large amount of research that has been performed in the various fields of its application ranging from biopulping, biobleaching to deinking technology. However, biopulping research has focused on biomechanical pulping, while little attention has been placed on chemical . pulping methods and the advantages derived from fungal pre-treatment. Therefore, the effect ofthe pretreatment of Eucalyptus grandis wood chips, with white-rot fungi, on the Kraft pulping process was investigated. Eucalyptus grandis is the predominant hardwood species used in the pulp and paper industry of South Africa. Initially a screening program was performed in order to evaluate the biopulping potential of 100 different fungal cultures, isolated in South Africa. Wood chips were inoculated with selected fungal cultures and incubated for a two-week period, at the relevant optimum growth temperatures, under aseptic conditions. Bio-degraded wood chips were pulped by means of the Kraft pulping process and the resultant pulp and black liquor were analysed for yield, shives, kappa number and residual active alkali. Twelve cultures, which showed the most potential for biopulping, were selected from the screening program for further evaluation and statistical validation. Results indicate that certain selected cultures affect significant improvements in the residual active alkali of just under 21%, while the kappa number was reduced by just less than 9%. Under the prevailing conditions, the chemical consumption decreased significantly by ca. 2%. No significant differences, between the test cultures and the control, were observed for yield and shive content. These results prove conclusively that Kraft biopulping of Eucalyptus grandis wood chips has a significantly positive effect on the pulp produced by this process~The-itnplication of savings in both pulping and bleaching chemicals are enormous. It is strongly suggested that a mill-scale trial be performed, upon which a full investigation into the financial implications of Biokraft pulping should be determined.