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

A1 Journal article (refereed)

Internal Authors/Editors

Publication Details

List of Authors: Whitty K, Kullberg M, Sorvari V, Backman R, Hupa M
Publication year: 2008
Journal: Bioresource Technology
Volume number: 99
Issue number: 3
Start page: 671
End page: 679
Number of pages: 9
ISSN: 0960-8524


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.


black liquor, char, pressure, pyrolysis, volatiles

Last updated on 2020-17-02 at 02:54