6533b823fe1ef96bd127f799
RESEARCH PRODUCT
Sulfur-free pulping of hot-water-extracted spruce sawdust
Joni LehtoMarjatta KleenRaimo Alénsubject
ExtractivesCarbohydrateschemistry.chemical_element02 engineering and technologyMolar-mass distributionLigninGeneral Materials Science040101 forestryAliphatic acidsHemicellulosestechnology industry and agricultureligniinifood and beveragesForestry04 agricultural and veterinary sciences021001 nanoscience & nanotechnologyPulp and paper industrySulfurchemistryHot-water pre-treatmentvisual_artNorway sprucevisual_art.visual_art_medium0401 agriculture forestry and fisheriesSawdust0210 nano-technologymetsäkuusihiilihydraatitdescription
Softwood (Picea abies) sawdust was hot-water-extracted with two multi-phase processes (160-180°C, 100-280 min, and liquor-to-wood ratio 5 l/kg) corresponding to P-factors of ~780 (yield 80.0%) and ~4580 (yield 72.4%). The pre-treated materials were then pulped with the soda-AQ cooking (170°C, NaOH charge 20%, AQ charge 0.1%, 30-150 min, and liquor-to-wood ratio 5 l/kg), resulting in a yield range of 36.1-61.4% (for reference cooks without pre-extraction 47.9-60.0%). It was observed that the pre-extraction under moderate conditions enhanced the dissolution especially of large-molar-mass lignin during cooking, and the total amount of the dissolved lignin was also higher than that removed from the material pre-extracted under harsh conditions. Additionally, in the former case the pulps with rather good properties (high yield and low amount of pulp rejects) were obtained, whereas in the latter case, a pronounced degradation of pulp carbohydrates to aliphatic acids was observed resulting in lower pulp properties. peerReviewed
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-01-01 |