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
Pulping process – general approach Kraft pulping under alkaline conditions converts wood or other fibrous feedstocks into a product mass with liberated fibres.1-4 In the conventional kraft pulping, “white liquor”, containing mainly the active cooking chemicals, sodium hydroxide (NaOH) and sodium sulphide (Na2S) in water, is used for cooking the chips. After cooking or digestion,
Authors & references
Author:
Raimo Alén, University of Jyväskylä
References:
- Kleppe, P. J. 1970. Kraft pulping. Tappi 53(1):35−47.
- Grace, T. M., Leopold, B., Malcolm, E. W. and Kocurek, M. J. (Eds.). 1989. Pulp and Paper Manufacture, Volume 5, Alkaline Pulping. 3rd edition. The Joint Textbook Committee of the Paper Industry, TAPPI&CPPA, USA and Canada. Pp. 23−44.
- Sjöström, E. 1993. Wood Chemistry − Fundamentals and Applications. 2nd edition. Academic Press, San Diego, CA, USA. Pp. 140−161.
- Alén, R. 2000. Basic chemistry of wood delignification. In: Stenius, P. (Ed.). Forest Products Chemistry. Fapet, Helsinki, Finland. Pp. 58−104.
- Mimms, A., Kocurek, M. J., Pyatte, J. A. and Wright, E. E. (Eds.). 1989. Kraft Pulping – A Compilation of Notes. Tappi Press, Atlanta, GA, USA. Pp. 55−76.
- Rydholm, S. 1965. Pulping Processes. Interscience Publishers, New York, NY, USA. P. 584.
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This page has been updated 10.05.2021