Impact of Selective Refining Combined with Inter-stage Ozone Treatment on Thermomechanical Pulp

• Main Authors: Yu Sun, Robert Lanouette, Jean-Noël Cloutier, Éric Pelletier, Michel Épiney
• Format: Article
• Language: English
• Published: North Carolina State University 2014-01-01
• Series: BioResources
• Subjects: Ozone; TMP; Fractionation; Selective refining; Properties; Energy reduction
• Online Access: http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_09_1_1225_Sun_Selective_Refining_Ozone_Pulp

The aim of this study was to evaluate the performance of selective refining combined with ozone inter-stage treatment in a TMP process. A fractionation process was carried out to separate the primary pulp into two fractions, a long-fibre fraction and a short-fibre fraction. Different charges of ozone, namely 1%, 1.5%, and 2%, were used to treat the long-fibre fraction, and only the treated pulp went to the second refining stage. Finally, the secondary pulp was recombined with the primary short-fibre fraction to be compared to a control TMP trial. Results showed that 21% of the total refining energy can be saved when 1.5% ozone inter-stage treatment is applied before selective refining compared with whole pulp refining, when the pulp freeness is 100 mL. At this level of ozone charge, a slight increase in tensile strength is observed with no significant variation in tear index.