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 (DES)
- 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 extractives – bleaching In the modern production of bleached kraft pulps, a large part of the lipophilic extractives originally present in the wood is removed during the kraft cooking and the subsequent oxygen-alkali delignification stages as well as in the washing of the corresponding pulps.1 A minor part of the wood extractives, however,
Authors & references
Author:
Raimo Alén, University of Jyväskylä
References
- Alén, R. 2000. Basic chemistry of wood delignification. In: Stenius, P. (Ed.). Forest Products Chemistry. Fapet Oy, Helsinki, Finland. Pp. 58−104.
- Dence, C. W. and Reeve, D. W. (Eds.). 1996. Pulp Bleaching – Principles and Practice. TAPPI Press, Atlanta, GA, USA. 868 p.
- Freire, C. S. R., Silvestre, A. J. D. and Pascoal Neto, C. 2005. Lipophilic extractives in Eucalyptus globulus kraft pulps. Behaviour during ECF bleaching. Journal of Wood Chemistry and Technology 25:67–80.
- Chirat, C., Lachenal, D., Mishra, S. P. and Passas, R. 2008. Effect of ozone bleaching on chemical, physico-chemical and physical properties of eucalyptus kraft pulp. Proceedings of TAPPI International Pulp Bleaching Conference, Québec City, Canada. Pp. 181–186.
- Barbosa, L. C. A., Maltha, C. R. A., Boas, L. A. V., Pinheiro, P. F. and Colodette, J. L. 2008. APPITA Journal 61(1):64–70.
- Holmbom, B. 1999. Extractives. In: Sjöström, E. and Alén, R. (Eds.). Analytical Methods in Wood Chemistry, Pulping, and Papermaking. Springer, Heidelberg, Germany. Pp. 125–148.
- Knuutinen, J. and Alén, R. 2007. Overview of analytical methods in wet-end chemistry. In: Alén, R. (Ed.). Papermaking Chemistry. 2nd edition. Finnish Paper Engineersʼ Association, Helsinki, Finland. Pp. 199–228.
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This page has been updated 20.01.2021