Pilot-Scale Investigation into the Effects of Alkaline Peroxide Pre-Treatments on Low-Consistency Refining of Primary Refined Softwood TMP

BioResources

Antti Luukkonen¹  Rodger Beatson¹  Xue Feng Chang²  James Olson³ 

[1] Canada;Department of Chemical and Biological Engineering, The University of British Columbia, Vancouver, BC, Canada V6T 1Z3;Pulp and Paper Centre, The University of British Columbia, Vancouver, BC, Canada V6T 1Z4;

关键词: Alkaline peroxide treatment;    TMP;    Low-consistency refining;    Refining intensity;    Energy saving;    Fibre cutting;    Acid group generation;    Tensile strength;   

DOI  :  10.15376/biores.11.1.2030-2042

来源: DOAJ

【 摘 要 】

Primary refined coarse softwood thermomechanical pulp was treated with alkaline peroxide prior to low-consistency (LC) refining. The effects of the pre-treatments on pulp quality, refinability, and electrical energy consumption were assessed. Four pre-treatments were conducted with alkali charges of 2.5 and 6% and peroxide charges of 3 and 4%. The pulps were refined to specific energies up to 600 kWh/t by multiple passes through an LC refiner at intensities of 90 and 150 kWh/t. It was found that alkaline peroxide treatments increased tear strength and protected the fibre from cutting, especially during high intensity refining below a specific energy of 300 kWh/t. Treatment with 6% NaOH and 4% or 3% H2O2 led to lower brightness gains and scattering coefficients but increased the tensile strength index by 31%, potentially lowering the total electrical energy required to achieve strong pulp. The enhancement of tensile strength caused by the highly alkaline peroxide mostly resulted from increased bonding, which was attributable to acid group generation rather than the promotion of further fibrillation during LC refining.

【 授权许可】

Unknown