Dithionite

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Dithionite General approach The objective of lignin-preserving bleaching processes of chemimechanical and mechanical pulps is to selectively eliminate colour-contributing groups (i.e., chromophores) (see Lignin-preserving or lignin-retaining bleaching), while maintaining pulp yield. Additionally, bleaching chemicals should themselves be colourless and run at reasonable cost.1-3 Two main bleaching chemicals, alkaline hydrogen peroxide (H2O2/NaOH, stage designation P) (see

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Authors & references

Author:

Raimo Alén, University of Jyväskylä

References:

Barton, R., Tredway, C., Ellis, M. and Sullivan, E. 1987. Hydrosulfite bleaching. In: Kocurek, M. J. (Ed.). Mechanical Pulping 3^rd edition. TAPPI Press, Atlanta, GA, USA. Pp. 227−237.
Ellis, M. E. 1996. Hydrosulfite (dithionite) bleaching. In: Dence, C. W. and Reeve, D. W. (Eds.). Pulp Bleaching – Principles and Practice. TAPPI Press, Atlanta, GA, USA. Pp. 491−512.
Kappel, J. 1999. Mechanical Pulps: from Wood to Bleached Pulp. TAPPI Press, Atlanta, GA, USA. Pp. 263−326.
Dence, C. W. 1996. Chemistry of mechanical pulp bleaching. In: Dence, C. W. and Reeve, D. W. (Eds.). Pulp Bleaching – Principles and Practice. TAPPI Press, Atlanta, GA, USA. Pp. 161−181.
Makarov, S. V. and Silaghi-Dumitrescu, R. 2013. Sodium dithionite and its relatives: past and present. Journal of Sulfur Chemistry 34(4):444−449.
Makarov, S. V., Horváth, A. K., Silaghi-Dumitrescu, R. and Gao, Q. 2017. Sodium Dithionite, Rongalite and Thiourea Oxides − Chemistry and Application. World Scientific, Singapore. 219 p.
Isoaho, J. P. 2019. Dithionite Bleaching of Thermomechanical Pulp – Chemistry and Optimal Conditions. Doctoral Thesis. University of Jyväskylä, Finland. 73 p.
Nayar, R. 1972. Manufacture of Sodium Dithionite from Sodium-Mercury Amalgam and Aqueous Solution of Sulfur Dioxide. Doctoral Thesis. The University of British Columbia, BC, Canada.
Jäkärä, J., Persson, M. and Mårtens, H. 2009. Bleaching of mechanical pulps. In: Lönnberg, B. (Ed.). Mechanical Pulping. 2^nd edition. Paper Engineers’ Association, Helsinki, Finland. Pp. 360−398.
Dietz, T., Schmidt, K. and Süss, H. U. 2008. Aspects of optimization of mechanical pulp bleaching – a comparison of alternative alkali sources for hydrogen peroxide bleaching. Das Papier 12:39−43.
Wayman, M. and Lem, W. J. 1970. Decomposition of aqueous dithionite. Part II. A reaction mechanism for the decomposition of aqueous sodium dithionite. Canadian Journal of Chemistry 48:782–787.
Cermăk, V. and M. Smutek .1975. Mechanism of decomposition of dithionite in aqueous solutions. Collection of Czechoslovak Chemical Communications 40:3241–3264.
Pemberton, R. S., Depew, M. C., Heitner, C. and Wan, J. K. S. 1995. Some mechanistic insights into a model bleaching process of quinones by bisulfite and dithionite: an ESR-CIDEP Study. Journal of Wood Chemistry and Technology 15:165–183.
Polčin, J. and Rapson, W. H. 1969. Spectrophotometric study of wood chromophores in situ. I. The method of differential (K/S)_λ curves related to bleaching and color reversion. TAPPI 52(10):1960–1965.
Auhorn, W. and Melzer, J. 1982. Die ökonomische Anpassung der Holzstoffbleiche an die fortschrittliche Papiertechnologie. Wochenblatt für Papierfabrikation 8:255–262.
Lindholm, C.-A. 1999. Bleaching. In: Sundholm, J. (Ed.). Mechanical Pulping. Fapet Oy, Helsinki, Finland. Pp. 313−343.
Sullivan, E. A. 1982. Hydrosulphite bleaching under adverse conditions: hydrogen sulphide formation and its chemical prevention. Pulp & Paper Canada 83(9):64−67.

This page has been updated 25.05.2021

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