Process for the electrochemical reductive bleaching of lignocellulosic pulp
AssigneeInternational Paper Company
InventorsMichael N. Hull, Vacheslav M. Yasnovsky
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Abstract
Reductive bleaching of lignin containing pulps employing polydentate ligand complexes of dipositive vanadium, chromium and titanium. High brightness pulps with good reversion stability are obtained. The process is essentially polution free as the reduced complexes can be repeatedly regenerated electrochemically.
Claims11
A continuous electrochemical reductive process for increasing the brightness of lignocellulosic pulp which comprises reacting said lignocellulosic pulp with a polydentate ligand complex of Cr.sup.++ or V.sup.++ formed by the electrochemical reduction of the complexed trivalent chromium or vanadium metal ion having a concentration from about 0.1 millimole to the upper limit of solubility of the complex wherein the lignocellulosic pulp is brightened during the reaction.
Dependencies are inferred from the claim text.