Potential of xylanase enzymes for boosting the ECF bleaching of several hardwood pulps | |
| Author | Darono Wikanaji |
| Call Number | AIT Thesis no.PP-03-8 |
| Subject(s) | Wood-pulp--Bleaching Xylanases |
| Note | A thesis submitted in patiial fulfillment of the requirements for the degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Limited use of enzymes in pulp and papermaking processes is mostly related to size and properties of enzyme in comparison to corresponding wood or nonwood fiber properties. Development steps of enzyme technology from research and development into commercial implementation, depend on how many major changes in the pulping process should be done, and how easy and cost efficient applications are in industrial scale. Several efforts are continuously ongoing to seek potential applications for enzymes. Xylan concentration is the biggest among all hemicelluloses in the wood, around 23 - 34 % of total dry weight of wood. Various hemicellulose types make the kraft chemical reaction very complex. Hexenuronic acid (Hex A), hydrolysis product of xylan by β-elimination of methanol from 4-0-methylglucuronic acid makes kappa number determination inaccurate, because unsaturated structure consumes permanganate in kappa number analysis. So this Hex A should be selectively removed before kappa number determination. At the moment, there is no well known or standardized technology to remove Hex A selectively. Xylanase treatment has been proposed to remove residual lignin and hexeuronic acid in Lignin Carbohydrate Complex (LCC) redeposited on fiber surfaces to get higher brightness and lower bleaching chemical consumption. Applying xylanase treatment with two commercial products before and after oxygen delignification, marginal brightness improvement was achieved. Chemical consumption as well as paper properties remained essentially unchanged. |
| Year | 2003 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Pulp and Paper Technology (PP) |
| Chairperson(s) | Malinen, Raimo |
| Examination Committee(s) | Kolehmainen, Heikki;Viljakainen, Esa |
| Scholarship Donor(s) | Government of Austria;AIT Fellowship |
| Degree | Thesis (M.Eng.) - Asian Institute of Technolog, 2003 |