Centre Technique De L'industrie Des Papiers, Cartons Et Celluloses

Arkema France

Institut Polytechnique De Grenoble

Michel Petit-Conil

Jeffrey S Tolan

Valérie Meyer

Jérôme Blanc

Christophe Calais

Gérard Mortha

Jennifer Marcon

Nathalie Marlin

Auphelia Burnet

J Mark A Hoddenbagh

The present invention relates to a method for bleaching an unbleached or pre-bleached paper pulp comprising at least the following consecutive steps: a) preparing an unbleached or pre-bleached paper pulp having a pH of at least 8, b) bringing the paper pulp obtained at the end of step a) into contact with chlorine dioxide, c) when the pH of the paper pulp obtained from step b) is lower than 10, adding at least one Br&#xf8;nsted base to the paper pulp, d) adding hydrogen peroxide to the paper pulp obtained at the end of step c), e) maintaining the paper pulp obtained at the end of step d) in a first bleaching tower, f) optionally, adding sulphuric acid to the paper pulp obtained at the end of step e) and maintaining the obtained paper pulp in a second bleaching tower, the method dispensing with the need for a step of washing the paper pulp before the end of step e), and, if applicable, before the end of step f).

Method for bleaching paper pulp

A method for producing mechanical paper pulp comprises: impregnating unprocessed wood, whereby unprocessed wood is exposed to an impregnating composition comprising at least a laccase enzyme and a formula mediator (I), wherein Rand Rare identical or different groups, chosen from among a hydrogen atom, a hydrocarbon chain, linear or branched, saturated or unsaturated, comprising 1 to 14 carbon atoms, wherein each hydrocarbon chain can be replaced by one or more functional groups chosen from among &#x2014;OH, &#x2014;SO, benzyl, amino, mercapto, keto or carboxyl, wherein Rand Rin combination can form a cyclical structure, to achieve impregnation of the wood; and mechanically refining the impregnated wood, such that a mechanical paper pulp is obtained. The disclosure also relates to an impregnating composition used in this method and to the use thereof in a method for producing mechanical paper pulp, as well as to a method for producing paper.

Enzymatic pretreatment of wood in a method for producing mechanical paper pulp

A method of producing hardwood pulp is provided. This method comprises treating hardwood chips with one or more than one Family 11 xylanase enzyme in the absence of adding an oxidizing enzyme for about 5 minutes to about 120 minutes, to produce a treated chip mixture. The treated chip mixture is then mechanically refined to produce the hardwood pulp.

Method for mechanical pulp production

Growing community of inventors

Grenoble, France

Michel Petit-Conil