Selectivity improvement and extractive removal by various pretreatment methods prior to oxygen delignification for Acacia mangium and mixed hardwood kraft pulps
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چکیده
The objective of this study was to evaluate different pretreatment methods prior to oxygen delignification on extractives removal and O-delignification selectivity. Four different pretreatment methods were used including ultrasonic treatment, hot water soaking, soda addition-preheating, and applying a high-shear mechanical pretretament. Acacia mangium and mixed hardwood (MHW) kraft pulps were used in this study. Mechanical pretreatment, prior to oxygen delignification, promoted a better selectivity for both Acacia mangium and MHW pulps. MHW kraft pulp did not show a significant extractive removal in all pretreatment methods during oxygen delignification. This was probably due to a low extractive content of pre O2 MHW kraft pulp to begin with. A dramatic extractive removal occurred on the Acacia mangium pulp that was pretreated with ultrasonic. The ultrasonic pretreatment followed by filtering induced extractive removal.
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