The fate of nitrogen in the chemical recovery process in a kraft pulp mill. Part III: The effect of some process variables

A1 Journal article (refereed)

Internal Authors/Editors

Publication Details

List of Authors: Kymalainen M, Holmstrom M, Forssen M, Hupa M
Publication year: 2001
Journal: Journal of Pulp and Paper Science
Journal acronym: J PULP PAP SCI
Volume number: 27
Issue number: 9
Start page: 317
End page: 324
Number of pages: 8
ISSN: 0826-6220


The effects of some process variables on the fate of N in the chem. recovery cycles of pulp mills were studied. The general picture of the relative flows of wood N in the cycle was the same for both hard and soft woods. However, the wood species was of significance for the N concns. in the cycle as well as for the level of NOx emissions from the boiler. The different ways to handle secondary condensates caused some minor changes in the routes of N in the cycle. The addn. of bio-​sludge (∼0.5 wt.​% of black liquor solids) to black liquor in the middle of the evapn. plant increased the N content of liquor by ∼30​%. However, this addn. and the feed of the high-​concn., low-​vol. gases and MeOH to the recovery boiler did not result in any change in the share of the smelt N of the liquor N or in any increase in the levels of NOx emissions in the boiler.


black liquors, chemical recovery, condensates, hardwoods, kraft mills, nitrogen, nitrogen oxides, process variables, sludge, smelt, softwoods

Last updated on 2020-21-01 at 03:07