Development of Xylanase Based Pulp Bleaching Process

Abstract

As per the industries norms in regulating and maintaining the environmental conditions, current interest in the implementing of biological treatment in pulp bleaching processes has arisen very fast in the last few years globally. Due to use of huge quantities of hazardous chemicals in bleaching process, generation of pollutants is rapidly increased in environment. To overcome this problem researchers and industrialist are working continuously and finding alternative solutions of these hazardous chemicals. Use of biotechnology in pulp bleaching process shows its high impact towards green technology. Enzymes manufactured from microbial sources are very helpful and useful for reducing the use of chemicals; resulting in reducing huge percentage of pollutants generation to save our environment. There are many commercial enzymes are easily available in the market now, which is highly alkalistable and thermostable in nature which are the best desired conditions for enzymatic bleaching. Laccases and xylanases suits and helps a lot in enzymatic bleaching for achieving higher pulp qualities with cost effective process as compared to conventional process. Xylanase bleaching is very much popular rather than laccase and delivers high quality pulp at very low cost. Due to a mediator needed for the use of laccase in the process; it leads to increase production cost as compared to xylanase bleaching process. In this study, we used four different commercial enzymes and studied their effect on bleaching of two different hardwood eucalyptus (E. globulus) and acacia (A. mangium) kraft pulps using different bleaching sequences. Out of these four enzymes; two enzymes were manufactured and gifted by Novozyme, India, one from DuPont Genencor Sciences, USA, and another from Dyadic International, USA and coded as EnzyA, EnzyB, EnzyC and EnzyD respectively for the study.