In present study, xylanase and laccase were produced in a cost-effective manner up to 10 kg substrate level and evaluated in elemental chlorine free bleaching of Eucalyptus kraft pulp. Compared to the pulp pre-bleached with xylanase (15%) or laccase (25%) individually, the ClO2 savings were higher with sequential treatment of xylanase followed by laccase (35%) at laboratory scale. The sequentia...

Common metrics for evaluating the efficiency of oxygen delignification include the kappa number and Klason lignin content. As a change in xylan content often leads to a change in HexA content, the kappa number must be corrected for the HexA contribution before evaluating the degree of oxygen delignification when trying to understand the process in detail. Questions could also be raised about th...

Wood-derived cellulosic fibers prepared in different ways were successfully employed to absorb simulated crude oil, demonstrating their possible use as absorbents in the case of oil spills. When dry fibers were used, the highest sorption capacity (six parts of oil per unit mass of fiber) was shown by bleached softwood kraft fibers, compared to hardwood bleached kraft and softwood chemithermomec...

the effect of fiber surface modification on physical and mechanical properties of kraft pulp wasstudied with and without chitosan. first, the amount of carboxyl groups of kraft pulp at differentaddition levels (0, 2, 3, 4 and 6%) of hydrogen peroxide was determined by means of methylene bluetest. then, the samples containing the highest carboxyl groups were treated at ph=8.5 with chitosan at0.7...

I n chemical pulping a large part of the wood is dissolved during digestion. The dry matter content of the generated black liquor is typically 12 to 18 wt% [1, 2]. In the case of kraft black liquors four main groups of organic constituents are present, 30-45 wt% ligneous material, 25-35 wt% saccharinic acids, about 10 wt% formic and acetic acid, and 3-5 wt% extractives. It also contains about 1...

Samples of bleached kraft pine cellulosic pulp, either treated with an enzyme preparation (a Thermomyces lanuginosus xylanase, an Aspergillus sp. cellulase, and a multienzyme preparation NS-22086 containing both these activities) or untreated, were refined in a laboratory PFI mill. The treatment with cellulases contained in the last two preparations significantly improved the pulp's susceptibil...

The screened Eucalyptus camendulensis chips were cooked in the laboratory at various alkalinities (14, 16, 18 and 20 per cent) and sulphidity (20, 30 and 40 per cent). Due to the variation in chemical charge, the pulp yield was found to be different. The average pulp yield was 50.6 per cent after washing and the final yield was obtained 40 per cent, which followed the normal kraft yield trend. ...

Corn stalk can be used as an alternative non-wood raw material to produce cellulosic dissolving grade pulp. In this work, the potential of corn stalk in the production of dissolving pulp (alpha-cellulose) was investigated. It was collect ed from a corn stalk farm of Kermanshah, Iran. The sequences of experimental work were: water and acid prehydrolysis at 160˚C for 30min, followed by Kraft pulp...