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Using additives for the removal of extractives in kraft pulping and bleaching of hardwood | |
Author | Xu, Chenglong |
Call Number | AIT Thesis no.PP-01-4 |
Subject(s) | Wood-pulp--Bleaching |
Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development |
Publisher | Asian Institute of Technology |
Abstract | The effect of additives (surfactants and dispersant) on kraft pulping and bleaching of Eucalyptus camaldulensis and Acacia mangium has been studied. The use of additives results in a more removal of extractives, and in a more uniform cook with lower screen rejects in eucalyptus, lower residual alkali, and in an improvement in brightness of eucalyptus pulps. At low additive charge level, a reduction of kappa number generated without clear loss of pulp yield in acacia cook. Additives resulted in a significant reduction of extractive content in laaft pulping and bleaching, but effect on extractive content was different between eucalyptus and acacia and among different additives. The highest reduction of extractive content reached 28.6% and 24.3% in eucalyptus and acacia cook respectively with additive A, followed by additive B and D, compared to cook without additives. In brown stock washing with additive C, reduction of extractive content in eucalyptus was higher than that in acacia. Extractive content fell sharply in eucalyptus oxygen delignification by using additives. The effect was not clear in acacia. In pulp bleaching, additive D gave higher reduction of extractive content than additive A and B for acacia pulps. Extractive content also reduced by using additive B and D in eucalyptus bleaching, but it was not obvious with additive A. |
Year | 2001 |
Type | Thesis |
School | School of Environment, Resources, and Development (SERD) |
Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
Academic Program/FoS | Pulp and Paper Technology (PP) |
Chairperson(s) | Kolehmainen, Heikki |
Examination Committee(s) | Retulainen, Elias ;Ruhanen, Maune |
Scholarship Donor(s) | Government of Finland |
Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2001 |