Characterization of process streams in TMP and CTMP pulp mills

Tobias Persson, Ann-Sofi Jönsson

Research output: Book/ReportReportResearch


Samples of process streams were withdrawn at various positions at one groundwood, four thermomechanical (TMP) and two chemical thermomechanical (CTMP) lines in four different pulp mills.
Samples were divided in fractions by size exclusion chromatography (SEC). Concentration of sugars in each fraction was determined by high-performance anion exchange chromatography.
The separate, but close response peaks of refraction index and UV absorbance in the SEC chromatograms, indicate that it is possible to separate polysaccharides and lignin by ultrafiltration. However, great care selecting cut-off of the membrane and operating conditions is needed.
The molecular mass distribution of galactoglucomannan (GGM) was rather similar in filtrate from TMP mill B and CTMP mill D. The relative amount of mannan molecules larger than 4 kDa was 81% in filtrate from mill B and 74% in filtrate from mill D.
The relative amount of molecules smaller than 4 kDa was 60% and 45% in filtrate from TMP mill A and SGW mill B.
Process water from TMP mill B and CTMP mill D was thus the most promising streams. Fraction 3 and 4 of these filtrates (with average molecular mass of 17 and 6 kDa) had a ratio between galactan, glucan and mannan similar to that found in GGM.
Original languageEnglish
Publisher[Publisher information missing]
Publication statusUnpublished - 2009

Publication series


Subject classification (UKÄ)

  • Chemical Engineering


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