Abstract: A method for selectively delignifying lignocellulosic materials and bleaching of pulp and dyes using a combination of an oxidative enzyme and a metal complex. More specifically, the process involves the oxidation of a transition metal redox complex by a phenol oxidizing enzyme such as laccase or peroxidase to mediate the catalytic delignification of chemical pulp and bleaching of textile dye. This process is unique in that only a catalytic amount of metal complex mediator is required on softwood or hardwood kraft pulp, and that recycling or regeneration of the mediator for further pulp delignification is possible. The redox mediator is characterized in that it contains a transition metal ion coordinated with molecules or ions in such a way that the complexes have a formal redox potential between 0.5 and 1.2 volt measured against a normal hydrogen electrode.
Type:
Grant
Filed:
October 10, 2000
Date of Patent:
December 9, 2003
Assignees:
Pulp and Paper Research Institute of Canada, Universié de Montréal
Inventors:
Robert Bourbonnais, Dominic Rochefort, Michael G. Paice, Sylvie Renaud, Dónal Leech