Nitrogen oxide formation in black liquor single droplet combustion

A1 Journal article (refereed)

Internal Authors/Editors

Publication Details

List of Authors: Kymalainen M, Forssen M, Kilpinen P, Hupa M
Publication year: 2001
Journal: Nordic Pulp and Paper Research Journal
Journal acronym: NORD PULP PAP RES J
Volume number: 16
Issue number: 4
Start page: 346
End page: 354
Number of pages: 9
ISSN: 0283-2631


Nitrogen oxide formation in single droplet combustion of black liquors was measured under different combustion conditions (droplet size 5-​45 mg, temp. 800-​900 °C, O2-​concn. 3-​21​%)​. The NO formation in relation to the carbon conversion is presented. The amts. of NO formed during pyrolysis (pyrolysis-​NO)​, i.e., from the burning of volatile nitrogen species, and during char burning stage (char-​NO) are reported. Under all conditions studied, the NO formation followed the carbon conversion up to about 40-​50​%, after which the NO formation stopped, and began again only when about 90​% of the carbon had been converted. The relative amt. of pyrolysis-​NO varied with droplet size at 900 °C and with oxygen concn. at 800°C. Possible mechanisms for these effects are suggested. The char-​NO originated mostly in the oxidn. of the inorg. residue left after the burnout of the char. The amt. of char-​NO depended on temp.: more NO was formed at 800 °C than at 900 °C. The implications of the findings for NOx emissions in black liquor burning in recovery boilers are discussed.


black liquor, char, measurement, nitrogen oxide, single droplet combustion., volatiles

Last updated on 2020-02-06 at 05:02