A new approach to improve dissolving pulp properties: spraying cellulase on rewetted pulp at a high fiber consistency

Cellulase treatment is a promising technology that will increase the reactivity of a prehydrolysis kraft (PHK) dissolving pulp. In this study, a cellulase solution was sprayed onto rewetted pulp at a very high consistency (about 60%) to increase its Fock reactivity with high efficiency and low cost. This novel and facile approach is based on favorable cellulose adsorption onto pulp fibers and high cellulose concentration at the reaction sites. Consequently, the enzymatic reactions towards cellulose fibers are more effective, thus a higher enzymatic performance in comparison with the conventional process. With the cellulase spraying technique under the conditions of 60% fiber consistency and 1.5 mg/g cellulase dosage at 12 h, the Fock reactivity of a PHK dissolving pulp increased from 51.22 to 82.64% with acceptable viscosity (469 mL/g). Herein, the proposed cellulase spraying technology is flexible and readily implementable in practice.