Effect of hydroxide and sulfite ion concentration in alkaline sulfite anthraquinone (ASA) pulping: A comparative study

Markus Paananen (Corresponding Author), Stella Rovio, Tiina Liitiä, Herbert Sixta (Corresponding Author)

Research output: Contribution to journalArticleScientificpeer-review

1 Citation (Scopus)

Abstract

Pulp and black liquor produced by alkaline sulfite anthraquinone (ASA) process were comprehensively characterized to evaluate the effects of ion concentration on the delignification and polysaccharide preservation. Scots pine wood meal was pulped at 160°C with a sulfite-to-hydroxide ion ratio of 0.75 and liquor-to-wood ratio of 200:1. Two concentration levels were studied in presence and absence of anthraquinone (AQ). Contrary to the expectations, already the lower concentration level (L-ASA) revealed rapid delignification in presence of AQ, while only moderate acceleration was obtained at the high concentration level (H-ASA). However, H-ASA liquor resulted in a slightly higher pulp yield of 1-2% (based on wood) but only in case of pulps with kappa numbers (KN) above 60. With progressing delignification, the yield advantage was gradually lost. The higher pulp yield at H-ASA conditions was mainly due to improved galactoglucomannan retention, which was around 2% on KN60 pulp and around 0.5% after prolonged delignification. The xylan content, on the other hand, was found to be 1% (based on wood) lower under H-ASA conditions compared to L-ASA conditions, which may be attributed to an increased solubility of short-chain polysaccharides at high alkali concentration.
Original languageEnglish
Pages (from-to)661-666
JournalHolzforschung
Volume69
Issue number6
DOIs
Publication statusPublished - 2015
MoE publication typeA1 Journal article-refereed

Keywords

  • anthraquinone
  • black liquor
  • degradation
  • dissolution of polysaccharides
  • galactoglucomannan (GGM) stabilization
  • Scots pine

Fingerprint Dive into the research topics of 'Effect of hydroxide and sulfite ion concentration in alkaline sulfite anthraquinone (ASA) pulping: A comparative study'. Together they form a unique fingerprint.

  • Cite this