Pulping and biorefining
- General approach and principles
- Extraction-based methods
- Separation of valuable extractives from trees
- Choosing the right solvent – hydrophobic or hydrophilic?
- Stemwood extractives-based products
- Operation modes and procedures in industrial extraction processes
- Exudate gums and latexes
- Hot-water extraction
- Wood extractives – general description
- Factors contributing to the loss of extractives
- Chemical changes in extractives during storage
- Bark extractives – terpenes and terpenoids
- Bark extractives – polyphenols and other minor compounds
- Use of deep eutectic solvents
- Chemical and biochemical conversion
- Thermochemical conversion
- Kraft pulping
- Wood material handling systems
- Pulping process-general approach
- Pulping technologies
- Drying of chemical pulps
- Chemical (market) pulps drying plant applications
- Recovery of cooking chemicals and by-products
- Integrated biorefinery concepts
- Oxygen-alkali delignification
- Delignifying or lignin-removing bleaching
- Other delignification methods
- Chemimechanical pulping
- Mechanical pulping
- Pulp characterisation and properties
Reactions of carbohydrates – oxygen-alkali delignification General aspects The term “selectivity” can be simply defined as the ratio of removal of pulp lignin to that of pulp carbohydrates.1 Pulp carbohydrates, cellulose (65−75 % of unbleached pulp) and hemicelluloses (20−30 % of unbleached pulp),2 are the structural components contributing to pulp strength. Hence, it is desirable
Authors & references
Author:
Raimo Alén, University of Jyväskylä
References:
- Salmela, M. 2007. Description of Oxygen-Alkali Delignification of Kraft Pulp Using Analysis of Dissolved Material. Doctoral Thesis. University of Jyväskylä, Finland.
- Alén, R. 2000. Basic chemistry of wood delignification. In: Stenius, P. (Ed.). Forest Products Chemistry. Fapet, Helsinki, Finland. Pp. 58−104.
- Dence, C. W. and Reeve, D. W. (Eds.). 1993. Pulp Bleaching ─ Principles and Practice. Tappi Press, Atlanta, GA, USA. 868 p.
- Sjöström, E. 1993. Wood Chemistry ─ Fundamentals and Applications. 2nd edition. Academic Press, San Diego, CA, USA. Pp. 166−198.
- Bajpai, P. 2005. Developments in Environmental Management – Environmentally Benign Approaches for Pulp Bleaching. Elsevier, Amsterdam, The Netherlands. 278 p.
- Suess, H. U. 2010. Pulp Bleaching Today. Walter de Gruyter, Berlin, Germany. 310 p.
- Malinen, R. 1974. Behavior of Wood Polysaccharides during Oxygen-Alkali Delignification. Doctoral Thesis. Helsinki University of Technology, Finland.
- McDonough, T. J. 1993. Oxygen delignification. In: Dence, C. W. and Reeve, D. W. (Eds.). Pulp Bleaching ─ Principles and Practice. Tappi Press, Atlanta, GA, USA. Pp. 213−239.
- Gellerstedt, G. 1996. Chemical structure of pulp components. In: Dence, C. W. and Reeve, D. W. (Eds.). Pulp Bleaching ─ Principles and Practice. Tappi Press, Atlanta, GA, USA. Pp. 91−111.
- Kolmodin, H. and Samuelson, O. 1971. Oxygen-alkali treatment of hemicellulose. 1. Experiments with corn-cob xylan. Svensk Papperstidning 74(10):301−309.
- Kolmodin, H. and Samuelson, O. 1972. Oxygen-alkali treatment of hydrocellulose. Svensk Papperstidning 75(9):369−372.
- Kolmodin, H. and Samuelson, O. 1973. Oxygen-alkali treatment of hemicellulose. 1. Experiments with birch xylan. Svensk Papperstidning 76(2):71−77.
- Ericsson, B., Lindgren, B. O. and Theander, O. 1973. Degradation of cellulose during oxygen bleaching. Oxidation and alkali treatment of D-glucosone. Cellulose Chemistry and Technology 7(5):581−591.
- Löwendahl, L. and Samuelson, O. 1974. Influence of iron and cobalt compounds upon oxygen-alkali treatment of cellulose. Svensk Papperstidning 77(16):593−602.
- Malinen, R. 1975. Behavior of wood polysaccharides during oxygen-alkali delignigication. Paperi ja Puu 57(4A):193−196,199−201,203−204.
- Alén, R. and Sjöström, E. 1991. Formation of low-molar-mass compounds during the oxygen delignification of pine kraft pulp. Holzforschung 45(Suppl.):83−86.
- Alén, R. 2011. Principles of biorefining. In: Alén, R. (Ed.). Biorefining of Forest Resources. Paper Engineers’ Association, Helsinki, Finland. Pp. 55−114.
- Samuelson, O. and Sjöberg, L. 1974. Spent liquor from oxygen-alkali cooking of birch. Cellulose Chemistry and Technology 8(1):39−48.
- Malinen, R. and Sjöström, E. 1995. Studies on the reactions of carbohydrates during oxygen bleaching. V. Degradation of xylose, xylosone, xylo-oligosaccharides and birch xylan. Paperi ja Puu 57(3):101−102,107−109,111−114.
- Young, R. A. and Gierer, J. 1976. Degradation of native lignin under oxygen-alkali conditions. Applied Polymer Symposia 28:1213−1223.
- Gierer, J. and Imsgard, F. 1977. The reactions of lignin with oxygen and hydrogen peroxide in alkaline media. Svensk Papperstidning 80(16):510−518.
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This page has been updated 19.05.2021