Sammanfattning
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.
Originalspråk | Odefinierat/okänt |
---|---|
Sidor (från-till) | 317–324 |
Antal sidor | 8 |
Tidskrift | Journal of Pulp and Paper Science |
Volym | 27 |
Nummer | 9 |
Status | Publicerad - 2001 |
MoE-publikationstyp | A1 Tidskriftsartikel-refererad |
Nyckelord
- black liquors
- chemical recovery
- condensates
- hardwoods
- kraft mills
- nitrogen
- nitrogen oxides
- process variables
- sludge
- smelt
- softwoods