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
Mechanical stage General approach The changes in the wood substance brought about by the reactions between sulphite liquors and wood influence wood softening, fiberising and refining in a rather complicated manner.1 Figure 1 shows an attempt to describe the phenomena involved. The reactions between sulphite and lignin lead to the softening of lignin that
Authors & references
Authors
Raimo Alén, University of Jyväskylä and Victoria Lindqvist, Forest Products Engineers have modified the text from the reference “Lindholm, C.-A., Nickull, O. and Pitkänen, M. 2009. Chemimechanical pulping. In: Lönnberg, B. (Ed.). Mechanical Pulping. 2nd edition. Paper Engineers’ Association, Helsinki, Finland. Pp. 247−281”.
References
- Lindholm, C.-A., Nickull, O. and Pitkänen, M. 2009. Chemimechanical pulping. In: Lönnberg, B. (Ed.). Mechanical Pulping. 2nd edition. Paper Engineers’ Association, Helsinki, Finland. Pp. 247−281.
- Konn, J. 2006. Process Chemistry in Chemithermomechanical Pulping. Doctoral Thesis. Åbo Akademi, Finland. 77 p.
- Vikström, B. and Hammar, L.-A. 1981. Softening of spruce wood during sulphite pulping and its relevance for the character of high yield pulps. Proceedings of 1981 International Symposium on Wood and Pulping Chemistry Notes. SPCI, Stockholm, Sweden. P. V:112.
- Höglund, H., Sohlin, U. and Tistad, G. 1976. Physical properties of wood in relation to chip refining. TAPPI 59(6):144.
- Atack, D. and Heitner, C. 1979. Dynamic mechanical properties of sulfonated eastern black spruce. Proceedings of 1979 International Mechanical Pulping Conference. Transactions of the Technical Section CPPA 5(4):TR99.
- Gietz, H. W. 1977. Basic wood raw material properties and their significance in mechanical pulping. Proceedings of 1977 International Mechanical Pulping Conference, The Finnish Paper Engineersʼ Association, Helsinki, Finland, (1):1.
- Higgins, H. G., Puri, V. and Garland, C. 1978. The effect of chemical pretreatments in chip refining. Appita 32(3):187.
- Franzén, R. 1986. General and selective upgrading of mechanical pulps. Nordic Pulp and Paper Research Journal 1(3):4−13.
- Åkerlund, G. and Jackson, M. 1984. CTMP – the pulp on the future. Proceedings of SPCI 1984 World Pulp and Paper Week, SPCI, Stockholm, Sweden. P. 42.
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This page has been updated 26.01.2021