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Evaluation of the extent of the oxidation reaction during chlorine bleaching of pulp


A modified method was developed to evaluate how much chlorine is consumed by the oxidation reaction during the chlorine bleaching process. This evaluation is, in principle, based on the sum of chloride produced during the chlorination stage (C-stage) and produced during alkali treatment of both the C-stage effluent and the chlorinated pulp. Results obtained by this method proved that about 50%–75% of chlorine was consumed by the oxidation reaction during chlorine bleaching, depending on the reaction condition of chlorination. Even under a reaction condition that is not favorable to an oxidation reaction (low pH), approximately three electrons were abstracted from one lignin structural unit by chlorine bleaching. This result provides additional evidence for our recent observation that lignin is extensively oxidized during chlorine bleaching even when pure chlorine without any chlorine dioxide substitution was used.


  1. 1.

    Rydholm SA (1965) Pulping processes. Wiley-Interscience, New York, pp 916–939

  2. 2.

    Giertz HW (1951) Developments in bleaching processes. Tappi 34(5):209–215

  3. 3.

    Grangaard DH (1956) Bleaching. I. The chlorination of pulp. Tappi 39(5):270–276

  4. 4.

    Tabei K, Kaneko Y, Akiyama T, Ueno T (1980) Studies on bleaching of pulps. Part 1. The oxidation reaction and the substitution reaction in chlorine treatment (in Japanese). Jpn Tappi J 34(9):621–628

  5. 5.

    Shintani H, Matsumoto Y, Ishizu A, Meshitsuka G (1994) Formation characteristics of chloroorganics from hardwood kraft pulp during chlorine bleaching. Seni Gakkaishi 50:587–592

  6. 6.

    Migita N, Nakano J, Ishizu A (1955) Studies on lignin. XXIV. On the chlorination of lignin (in Japanese). Mokuzai Gakkaishi 1:55–59

  7. 7.

    Shintani H, Matsumoto Y, Meshitsuka G (1996) The unsuitability of AOX as a measure of the organic chlorine content of C-stage effluents. J Pulp Paper Sci 22(10):7372–7375

  8. 8.

    Shintani H, Matsumoto Y, Meshitsuka G (1995) Structure of high molecular weight chlorolignin prioduced by chlorine bleaching. In: Proceedings of 8th ISWPC (vol II), pp 309–314

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Correspondence to Keiichi Koda.

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Koda, K., Shintani, H., Matsumoto, Y. et al. Evaluation of the extent of the oxidation reaction during chlorine bleaching of pulp. J Wood Sci 45, 149–153 (1999).

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Key words

  • Chlorine bleaching
  • Alkali extraction
  • Oxidation
  • Substitution reaction
  • Chloride
  • Ion chromatography