Wood pulp treatment
AssigneeUniversity of New Brunswick
InventorsKecheng LI, Andre PELLETIER, Yu ZHAO
Life of this patent
Estimating the term…
Abstract
A process using a multicomponent enzyme preparation to treat screened once refined pulps and reduces the specific energy consumption and/or increasing production while maintaining or increasing handsheet physical properties. The enzyme preparation has a major endoglucanase activity, a significant mannanase activity and a relatively small cellobiohydrolase activity. This enzyme mixture is prepared from a genetically modified strain of Trichoderma reseii.
Claims21
A method of manufacturing a wood pulp, the method comprising:
- exposing a mechanical wood pulp to an enzymatic solution comprising an endoglucanase (EG) and a cellbiohydrolase (CBH), wherein the ratio of enzymatic activity of EG:CBH is at least 3, for a sufficient amount of time to reduce energy consumption during subsequent refining of the exposed pulp in which the freeness of the pulp (CSF) is reduced by at least 10% in comparison to the freeness of the same pulp which has not been exposed to the enzymatic solution while at least maintaining the tensile strength of a handsheet produced from said subsequently refined pulp in comparison with a handsheet produced from the same pulp which has not been exposed to the enzymatic solution, the tensile strength being determined according to TAPPI standard T 205 sp-06.
A method for producing a paper product comprising the steps of:
- (a) introducing mechanical wood pulp into a vessel;
- (b) introducing into the vessel an enzymatic solution comprising an endoglucanase (EG), a cellbiohydrolase (CBH) and a mannanase (MAN) wherein the ratio of enzymatic activity of EG:CBH is at least 3, and the ratio of enzymatic activity of MAN:CBH is at least 1.5;
- (c) waiting a length of time sufficient for the freeness of the pulp to be reduced to a selected level of freeness of fibers in the pulp;
- and (d) making the paper product with the pulp produced, the paper having a tensile strength at least as great as paper produced from the mechanical wood pulp by the method without exposure to said enzymatic solution.
A method of manufacturing a wood pulp the method comprising:
- exposing a mechanical wood pulp to an enzymatic solution comprising an endoglucanase (EG), a cellbiohydrolase (CBH) and a mannanase (MAN) wherein the ratio of enzymatic activity of EG:CBH is at least 3, and the ratio of enzymatic activity of MAN:CBH is at least 1.5, for a sufficient amount of time to reduce energy consumption during subsequent refining of the exposed pulp in comparison to energy consumption during refining of the same pulp which has not been exposed to the enzymatic solution while at least maintaining the tensile strength of a handsheet produced from said subsequently refined pulp in comparison with a handsheet produced from the same pulp which has not been exposed to the enzymatic solution, the tensile strength being determined according to TAPPI standard T 205 sp-06.
Dependencies are inferred from the claim text.