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

Yu Sun, Robert Lanouette, Jean-Noël Cloutier, Éric Pelletier, Michel Épiney


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.


Ozone; Fractionation; Selective refining; TMP; Energy reduction; Properties

Full Text: PDF

Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022,; Lucian A. Lucia, (919) 515-7707, URLs:; ISSN: 1930-2126