Journal of South China University of Technology (Natural Science Edition) ›› 2010, Vol. 38 ›› Issue (8): 45-50.doi: 10.3969/j.issn.1000-565X.2010.08.009

• Chemistry & Chemical Engineering • Previous Articles     Next Articles

Chlorine Dioxide Bleaching Reinforced by Alkaline Extraction and Corresponding ECF Bleaching Sequences for Wheat Straw Pulp

Zhao De-qing 1.2  Chen Ke-fu1  Mo Li-huan1  Li Jun1  Xu Jun1  Yang Ren-dang1  Yang Fei1   

  1. 1. State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, Guangdong, China; 2. School of Chemistry Engineering and Material, Dalian Polytechnic University, Dalian 116034, Liaoning, China
  • Received:2009-08-11 Revised:2009-10-26 Online:2010-08-25 Published:2010-08-25
  • Contact: 赵德清（1975-），男，博士生，主要从事制浆清洁生产与污染控制研究． E-mail:paperzdq@126．com
  • About author:赵德清（1975-），男，博士生，主要从事制浆清洁生产与污染控制研究．
  • Supported by:

    国家科技支撑计划项目（2006BA032806-2）

PDF

1192

Abstract:

Four kinds of alkaline extraction approaches, including the conventional, the oxygen-reinforced, the H2O2-reinforced and the oxygen-and-H2O2-reinforced ones （E, E0, Ep and E0p） , were used to modify ClO2-delignified （D0） wheat straw pulp, and the modification effects of these four approaches on the subsequent bleaching stage （D1） were explored. In addition, various elemental chlorine-free （ECF） bleaching sequences, such as D0ED1, D0P, DoA/QP, D0EP, D0EpD1 and D0EpP, were comparatively investigated. The results indicate that （ 1 ） the modification effects of different alkaline extraction approaches on the residual lignin of Do stage are different from one other; （2） for the subsequent D1 stage, the bleachability of D1 pulp varies in an order of D0E0P 〉 D0Ep 〉 D0E0 〉 D0E; （3） in the D0ED1 bleaching sequences, the increase of ClO2 dosage in D1 stage results in the brightness enhancement in a certain degree, especially at an optimized ClO2 dosage of 0. 8% -1.0% ; （4） as compared with the other sequences, D0EpD1 and D0EpP sequences are both of better bleaching effect; and （5） with D0EpD1 and DoEpP bleaching sequences, the final brightness of bleached wheat straw pulp reaches 82.3% ISO and 83.8% ISO, respectively, which means that both D0EpD1 and DoEpP sequences are applicable to the ECF short-sequence bleaching of wheat straw pulp.

Key words: alkaline extraction, wheat straw pulp, chlorine dioxide bleaching, ECF bleaching