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
Oxygen-alkali delignification Kraft pulping in delignification of wood and non-wood is the most widely used process in the production of chemical pulps. As a successive process stage of the kraft pulping process, oxygen-alkali delignification (or oxygen delignification) 1-5 has acquired an important role lowering the residual lignin content in pulp prior to actual bleaching (see
Authors & references
Author:
Raimo Alén, University of Jyväskylä
References:
- van Lierop, B., Liebergott, N., Teodorescu, G. and Kubes, G. J. 1986. Oxygen in bleaching sequences ─ an overview. Pulp & Paper Canada 87(5):T193–T197.
- Sjöström, E. 1993. Wood Chemistry ─ Fundamentals and Applications. 2nd edition. Academic Press, San Diego, CA, USA. Pp. 166–198.
- 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.
- Alén, R. 2000. Oxygen-alkali delignification. In: Stenius, P. (Ed.). Forest Products Chemistry. Fapet, Helsinki, Finland. Pp. 86–93.
- Salmela, M. 2007. Description of Oxygen-alkali Delignification of Kraft Pulp Using Analysis of Dissolved Material. Doctoral Thesis. University of Jyväskylä, Finland.
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This page has been updated 19.05.2021