Influence of pressure on pyrolysis of black liquor: 1. Swelling

K Whitty, R Backman, Mikko Hupa

    Research output: Contribution to journalArticleScientificpeer-review

    33 Citations (Scopus)


    This is the first of two papers concerning the behavior of black liquor during pyrolysis under pressurized conditions. Two industrial kraft liquors were pyrolyzed in a laboratory-scale pressurized single particle reactor and a pressurized grid heater at temperatures ranging from 650 to 1100 degrees C and at pressures between 1 and 20 bar. The dimensions of the chars produced were measured and the specific swollen volume was calculated. Swelling decreased roughly logarithmically over the pressure range 1-20 bar. An expression is developed to predict the specific swollen volume at elevated pressure when the volume at 1 bar is known. The bulk density of the char increased with pressure, indicating that liquors will be entrained less easily at higher pressures.
    Original languageUndefined/Unknown
    Pages (from-to)663–670
    Number of pages8
    JournalBioresource Technology
    Issue number3
    Publication statusPublished - 2008
    MoE publication typeA1 Journal article-refereed


    • black liquor
    • bulk density
    • pressure
    • pyrolysis
    • swelling

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