Enzyme‐based approaches for pitch control in thermomechanical pulping of softwood and pitch removal in process water

Abstract

BACKGROUND: In the pulp and paper manufacturing process, pitch colloidal particles have a tendency to agglomerate and deposit on pulp fibres and equipments. They reduce the efficiency of the washer, increase the dirt count and bleach chemical consumption, reduce pulp brightness thus leading to paper defects. Triglycerides are considered to be the most problematic compounds during the manufacturing of mechanical and acidic sulfite pulps from various softwood species.

Production and Partial Characterization of Lipase from Pseudomonas putida

“…Increasing or decreasing the temperature causes a decrease in enzyme units showing that P. putida is a mesophilic bacterium 30°C. Similar results have been shown by Padhiar et al [15] for P. aeruginosa and Kiran et al [16] who found 30°C as the optimum temperature for enzyme production from Pseudomonas sp.…”

Overview of Analytical Procedures for Fatty and Resin Acids in the Papermaking Process

“…The degradation of wood extractives has been conducted with enzymes and microorganisms in the water phase as well as in the wood chips or pulp by woodinhabiting fungi, to eliminate the possibility of lipophilic extractives leaching into process waters (Farrell et al 1997;Burnes et al 2000;Dorado et al 2001;Kallioinen et al 2003;Gutiérrez et al 2006Gutiérrez et al , 2009van Beek et al 2007;Dubé et al 2008;Widsten and Kandelbauer 2008). Such treatment can take from several hours to several days; the degradation of the extractives with enzymes/microorganisms is a very selective reaction when DCS is to be eliminated.…”

Fungi and Their Enzymes for Pitch Control in the Pulp and Paper Industry

“…In the reaction of laccase with trilinolein, the predominant oxidation products were monohydroperoxides, bishydroperoxides, and epoxides. Likewise, a >30% decrease of lipophilic extractives present in softwood pulp (TMP pulping) and derived process water was reported (Buchert et al 2002;Dubé et al 2008;Zhang et al 2000Zhang et al , 2005.…”

“…The optimum temperature range of this Resinase HT is 70-85 C. Currently, Resinase A2X and Resinase HT are used in mills from USA, Canada, China, Japan, and other countries in the Far East (where wood species with high resin content are handled). Very recently, it was shown that combining a novel biosurfactant with a lipase can reduce the concentration of a broad range of extractives in softwood TMP pulps (Dubé et al 2008). Lipase treatments were shown to successfully reduce the triglycerides in pulps, but besides triglycerides, other disturbing compounds such as free and esterified sterols, resin acids, fatty alcohols, alkanes, etc.…”