Influence of pressure on pyrolysis of black liquor: 2. Char yields and component release

K Whitty, M Kullberg, V Sorvari, R Backman, Mikko Hupa

    Research output: Contribution to journalArticleScientificpeer-review

    30 Citations (Scopus)


    This is the second in a series of papers concerning the behavior of black liquor during pyrolysis at elevated pressures. Two industrial black liquors were pyrolyzed under pressurized conditions in two laboratory-scale devices, a pressurized single-particle reactor and a pressurized grid heater. Temperatures ranging between 650 and 1100 degrees C and pressures in the range 1-20 bar were studied. Char yields were calculated and based on analysis of some of the chars the fate of carbon, sodium, potassium and sulfur was determined as a function of pyrolysis pressure. At temperatures below 800 degrees C little variation in char yield was observed at different pressures. At higher temperatures char yield increased with pressure due to slower decomposition of sodium carbonate. For the same reason, sodium release decreased with pressure. Sulfur release, however, increased with pressure primarily because there was less opportunity for its capture in the less-swollen chars.
    Original languageUndefined/Unknown
    Pages (from-to)671–679
    Number of pages9
    JournalBioresource Technology
    Issue number3
    Publication statusPublished - 2008
    MoE publication typeA1 Journal article-refereed


    • black liquor
    • char
    • pressure
    • pyrolysis
    • volatiles

    Cite this