A comparison of cold and hot caustic extraction of a spruce dissolving sulfite pulp prior to final bleaching
2013 (English)In: Appita journal, ISSN 1038-6807, Vol. 66, no 3, 229-234 p.Article in journal (Refereed) Published
A magnesium sulfite pulp producer modified its pulping process to dissolving pulping in 2011 and needed a purification stage after the digester to obtain a sufficiently low hemicellulose content. The dissolving pulp was intended for viscose production and an R-18 value of at least 95% and an intrinsic viscosity below 550 dm(3)/kg was requested. The results showed, as could be expected, a correlation between lower dissolving pulp yield and a higher degree Of purification with respect to cellulose. The R-18 values and the intrinsic viscosities of the dissolving pulps were found to increase with increasing sodium hydroxide concentration and/or higher temperature in the extraction Stage. The pulp yield was found to be higher with higher temperature for the cold caustic extraction stage (CCE); for hot caustic extraction (HQ E) the pulp yield became lower with higher temperature. The specified R-18 value was easiest to reach using hot caustic extraction.
Place, publisher, year, edition, pages
Appita , 2013. Vol. 66, no 3, 229-234 p.
caustic extraction, caustic purification, cellulose, dissolving pulp, hemicellulose, spruce, sulfite
Chemical Engineering Other Chemical Engineering
Research subject Chemical Engineering
IdentifiersURN: urn:nbn:se:kau:diva-38607ISI: 000321998100022OAI: oai:DiVA.org:kau-38607DiVA: diva2:875044