Industrial Production of Enzyme Treated Kraft Pulp from Radiata Pine, 1997 Biological Sciences Symposioum Proceedings

Celulosa Arauco y Constitucion SA from Chile operates three pulp mills. One of them produces about 1200 tons per day of market Kraft pulp from radiata pine. The bleaching sequence most commonly employed to reach the target brightness of 90 ISO id D100E0D1ED2. With the aim of reducing the consumption of chlorine dioxide, during two years the mill explored the feasability of using xylanases prior the application of the chemical sequence. Since results obtained first at a laboratory scale and then at mid trials were encouraged, the mill decided to encorporate enzymes to the production line about 15 months ago. Since then biobleaching has been operating at Arauco mill on a regular basis, with savings of ClO2 of about 2.8 kg/ADT of pulp. In turn the consumption of sodium hydroxide and sulfuric acid has increased about 1.0 and 4.5 kg/ADT pulp, respectively. The AOX of the effluent is about 15% lower than that observed with the standard bleaching proceedure.