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
Chemistry of oxygen Oxygen has become established as a weak oxidant in many industrial processes including conventional bleaching sequences and oxygen-alkali delignification already for several decades ago.1 At normal temperatures and pressures, two atoms of oxygen (O) bind to form dioxygen (O2), which is a colourless and odourless diatomic gas.2 Dioxygen has a triplet electronic
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.
- Cotton, F. A. and Wilkinson, G. 1988. Advanced Inorganic Chemistry. 5th edition. John Wiley & Sons, New York, NY, USA. Pp. 449–452.
- Norin, T. 1971. Träkemiska aspekter på syrgasblekning. Svensk Papperstidning 74(22):767–770.
- 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.
- Sjöström, E. 1981. The chemistry of oxygen delignification. Paperi ja Puu 63(6,7):438–442.
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This page has been updated 25.05.2021