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
Peroxide General approach Hydrogen peroxide (H2O2) (referred to simply as “peroxide”, stage designation P) can oxidise the specific chromophoric groups in the lignin (see Lignin-preserving or lignin retaining bleaching) resulting in the colour removal.1 However, in this bleaching process, H2O2 alone is not enough and also alkali (NaOH) is needed for the bleaching reactions. Since H2O2
Authors & references
Author:
Raimo Alén, University of Jyväskylä
References:
- Kappel, J. 1999. Mechanical Pulps: from Wood to Bleached Pulp. TAPPI Press, Atlanta, GA, USA. Pp. 263−326.
- Gellerstedt, G. 2001. Pulping chemistry. In: Hon, D. N.-S. and Shiraishi, N. (Eds.). 2001. Wood and Cellulosic Chemistry. 2nd edition. Marcel Dekker, New York, NY, USA. Pp. 859−905.
- Jäkärä, J., Persson, M. and Mårtens, H. 2009. Bleaching of mechanical pulps. In: Lönnberg, B. (Ed.). Mechanical Pulping. 2nd edition. Paper Engineers’ Association, Helsinki, Finland. Pp. 360−398.
- Tamper, J. 2009. Water Circulations for Effective Bleaching of High-brightness Mechanical Pulps. Doctoral Thesis. Lappeenranta University of Technology, Finland. 95 p.
- Lachenal, D., de Choudens, C. and Bourson, L. 1987. Bleaching of mechanical pulp to very high brightness. TAPPI Journal 70(3):119−122.
- Lippert, G. V. 1991. Mill experience in a PGW bleach plant using high consistency and medium consistency technology. Proceedings of 1991 Mechanical Pulping Conference, June 2−5, 1991, Minneapolis, MN, USA. Pp. 171−175.
- Abbot, J., Ault, K., Vanderaa, S. and Wright, P. 1992. Reagent recycling in peroxide bleaching. Appita 45(6):393−396.
- Lindholm, C.-A. 1999. Bleaching. In: Sundholm, J. (Ed.). Mechanical Pulping. Fapet Oy, Helsinki, Finland. Pp. 313−343.
- Parker, M. and Mackie, D. 2003. Benefits of washing mechanical pulp. Proceedings of Mechanical Pulping Conference, June 2−5, 2003, Quebec, Canada. Pp. 133−139.
- Blechschmidt. J. and Strunz, A.-M. 1994. Technisch-wirtschaftliche Entwicklung der Holzstofferzeugung. Wochenblatt für Papierfabrikation 19:762.
- Colodette, J. L., Rothenberg, S. and Dence, C. W. 1988. Factors affecting hydrogen peroxide stability in the brightening of mechanical and chemimechanical pulps. I. Hydrogen peroxide stability in the absence of stabilizing systems. Journal of Pulp and Paper Science 14(6):J126.
- Gavelin, G. 1966. Current trends in methods of bleaching mechanical pulp. Paper Trade Journal 150(26):42.
- Soteland, N. 1993. Modern bleaching of high yield pulps. Proceedings of Mechanical Pulping Conference, PTF, Oslo, Norway. P. 373.
- Dence, C. W. and Omori, S. 1986. A survey of hydrogen peroxide bleaching of mechanical and chemimechanical pulp – factors affecting brightness. TAPPI Journal 69(10):120.
Videos
Exercises
This page has been updated 25.05.2021