Ash formation during fluidized bed incineration of paper mill waste sludge

Jouko Latva-Somppi, Mikko Moisio, Esko Kauppinen, Tuomas Valmari, Petri Ahonen, Unto Tapper, Jorma Keskinen

Research output: Contribution to journalArticleScientificpeer-review

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Abstract

Ash formation during industrial-scale bubbling fluidized bed (BFB) and circulating fluidized-bed (CFB) combustion of bark, waste wood and paper mill sludges has been studied. The principal ash formation mechanism was the sintering of 0.2–4 μm paper filler mineral particles into larger, porous ash agglomerates from 10 to 200 μm in size which dominated the fly ash total mass and specific surface area. Fly ash total mass concentration at the electrostatic precipitator inlet conditions varied from 4.5 g N-1 m-3 at BFB to 8.3 g N-1 m-3 at CFB while the respective total surface area concentrations as determined with nitrogen absorption were 32 and 83 m2 N-1 m-3. During bark combustion in the BFB, we observed an ultrafine mode at 0.05 μm consisting of spherical particles and their chain-type agglomerates. Ultrafine mode mass and surface area concentrations were 3 and 0.1 m2 N-1 m-3, respectively, as determined with the electrical low-pressure impactor and with the differential mobility analyzer. Ultrafine particles were formed via nucleation of volatilized ash species followed by particle growth via collision and coalescence and via vapor condensation. During waste wood combustion in the CFB, ultrafine particle concentration was significantly lower than during bark combustion in BFB, indicating reduced ash volatilization during CFB combustion. When co-firing sludge with bark in the BFB and with waste wood in the CFB ultrafine particle concentration was further reduced. Results from continuous aerosol measurements by the electrical low-pressure impactor (ELPI), by the scanning differential mobility analyzer (SMPS) and by the tapered element oscillating microbalance (TEOM) as the function of BFB process conditions suggest that co-combustion of sludge reduces significantly the ultrafine particle formation rate. No significant enrichment of alkali and trace metals in the ultrafine particles was observed.
Original languageEnglish
Pages (from-to)461-480
JournalJournal of Aerosol Science
Volume29
Issue number4
DOIs
Publication statusPublished - 1998
MoE publication typeA1 Journal article-refereed

Fingerprint

Ashes
Waste incineration
Sewage sludge
incineration
Fluidized beds
mill
ash
sludge
combustion
Wood wastes
bark
Coal Ash
Fluidized bed combustion
surface area
Fly ash
fly ash
Particles (particulate matter)
low pressure
Fluidized bed process
alkali metal

Keywords

  • fluidized beds

Cite this

Latva-Somppi, J., Moisio, M., Kauppinen, E., Valmari, T., Ahonen, P., Tapper, U., & Keskinen, J. (1998). Ash formation during fluidized bed incineration of paper mill waste sludge. Journal of Aerosol Science, 29(4), 461-480. https://doi.org/10.1016/S0021-8502(97)00291-7
Latva-Somppi, Jouko ; Moisio, Mikko ; Kauppinen, Esko ; Valmari, Tuomas ; Ahonen, Petri ; Tapper, Unto ; Keskinen, Jorma. / Ash formation during fluidized bed incineration of paper mill waste sludge. In: Journal of Aerosol Science. 1998 ; Vol. 29, No. 4. pp. 461-480.
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abstract = "Ash formation during industrial-scale bubbling fluidized bed (BFB) and circulating fluidized-bed (CFB) combustion of bark, waste wood and paper mill sludges has been studied. The principal ash formation mechanism was the sintering of 0.2–4 μm paper filler mineral particles into larger, porous ash agglomerates from 10 to 200 μm in size which dominated the fly ash total mass and specific surface area. Fly ash total mass concentration at the electrostatic precipitator inlet conditions varied from 4.5 g N-1 m-3 at BFB to 8.3 g N-1 m-3 at CFB while the respective total surface area concentrations as determined with nitrogen absorption were 32 and 83 m2 N-1 m-3. During bark combustion in the BFB, we observed an ultrafine mode at 0.05 μm consisting of spherical particles and their chain-type agglomerates. Ultrafine mode mass and surface area concentrations were 3 and 0.1 m2 N-1 m-3, respectively, as determined with the electrical low-pressure impactor and with the differential mobility analyzer. Ultrafine particles were formed via nucleation of volatilized ash species followed by particle growth via collision and coalescence and via vapor condensation. During waste wood combustion in the CFB, ultrafine particle concentration was significantly lower than during bark combustion in BFB, indicating reduced ash volatilization during CFB combustion. When co-firing sludge with bark in the BFB and with waste wood in the CFB ultrafine particle concentration was further reduced. Results from continuous aerosol measurements by the electrical low-pressure impactor (ELPI), by the scanning differential mobility analyzer (SMPS) and by the tapered element oscillating microbalance (TEOM) as the function of BFB process conditions suggest that co-combustion of sludge reduces significantly the ultrafine particle formation rate. No significant enrichment of alkali and trace metals in the ultrafine particles was observed.",
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Latva-Somppi, J, Moisio, M, Kauppinen, E, Valmari, T, Ahonen, P, Tapper, U & Keskinen, J 1998, 'Ash formation during fluidized bed incineration of paper mill waste sludge', Journal of Aerosol Science, vol. 29, no. 4, pp. 461-480. https://doi.org/10.1016/S0021-8502(97)00291-7

Ash formation during fluidized bed incineration of paper mill waste sludge. / Latva-Somppi, Jouko; Moisio, Mikko; Kauppinen, Esko; Valmari, Tuomas; Ahonen, Petri; Tapper, Unto; Keskinen, Jorma.

In: Journal of Aerosol Science, Vol. 29, No. 4, 1998, p. 461-480.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Ash formation during fluidized bed incineration of paper mill waste sludge

AU - Latva-Somppi, Jouko

AU - Moisio, Mikko

AU - Kauppinen, Esko

AU - Valmari, Tuomas

AU - Ahonen, Petri

AU - Tapper, Unto

AU - Keskinen, Jorma

PY - 1998

Y1 - 1998

N2 - Ash formation during industrial-scale bubbling fluidized bed (BFB) and circulating fluidized-bed (CFB) combustion of bark, waste wood and paper mill sludges has been studied. The principal ash formation mechanism was the sintering of 0.2–4 μm paper filler mineral particles into larger, porous ash agglomerates from 10 to 200 μm in size which dominated the fly ash total mass and specific surface area. Fly ash total mass concentration at the electrostatic precipitator inlet conditions varied from 4.5 g N-1 m-3 at BFB to 8.3 g N-1 m-3 at CFB while the respective total surface area concentrations as determined with nitrogen absorption were 32 and 83 m2 N-1 m-3. During bark combustion in the BFB, we observed an ultrafine mode at 0.05 μm consisting of spherical particles and their chain-type agglomerates. Ultrafine mode mass and surface area concentrations were 3 and 0.1 m2 N-1 m-3, respectively, as determined with the electrical low-pressure impactor and with the differential mobility analyzer. Ultrafine particles were formed via nucleation of volatilized ash species followed by particle growth via collision and coalescence and via vapor condensation. During waste wood combustion in the CFB, ultrafine particle concentration was significantly lower than during bark combustion in BFB, indicating reduced ash volatilization during CFB combustion. When co-firing sludge with bark in the BFB and with waste wood in the CFB ultrafine particle concentration was further reduced. Results from continuous aerosol measurements by the electrical low-pressure impactor (ELPI), by the scanning differential mobility analyzer (SMPS) and by the tapered element oscillating microbalance (TEOM) as the function of BFB process conditions suggest that co-combustion of sludge reduces significantly the ultrafine particle formation rate. No significant enrichment of alkali and trace metals in the ultrafine particles was observed.

AB - Ash formation during industrial-scale bubbling fluidized bed (BFB) and circulating fluidized-bed (CFB) combustion of bark, waste wood and paper mill sludges has been studied. The principal ash formation mechanism was the sintering of 0.2–4 μm paper filler mineral particles into larger, porous ash agglomerates from 10 to 200 μm in size which dominated the fly ash total mass and specific surface area. Fly ash total mass concentration at the electrostatic precipitator inlet conditions varied from 4.5 g N-1 m-3 at BFB to 8.3 g N-1 m-3 at CFB while the respective total surface area concentrations as determined with nitrogen absorption were 32 and 83 m2 N-1 m-3. During bark combustion in the BFB, we observed an ultrafine mode at 0.05 μm consisting of spherical particles and their chain-type agglomerates. Ultrafine mode mass and surface area concentrations were 3 and 0.1 m2 N-1 m-3, respectively, as determined with the electrical low-pressure impactor and with the differential mobility analyzer. Ultrafine particles were formed via nucleation of volatilized ash species followed by particle growth via collision and coalescence and via vapor condensation. During waste wood combustion in the CFB, ultrafine particle concentration was significantly lower than during bark combustion in BFB, indicating reduced ash volatilization during CFB combustion. When co-firing sludge with bark in the BFB and with waste wood in the CFB ultrafine particle concentration was further reduced. Results from continuous aerosol measurements by the electrical low-pressure impactor (ELPI), by the scanning differential mobility analyzer (SMPS) and by the tapered element oscillating microbalance (TEOM) as the function of BFB process conditions suggest that co-combustion of sludge reduces significantly the ultrafine particle formation rate. No significant enrichment of alkali and trace metals in the ultrafine particles was observed.

KW - fluidized beds

U2 - 10.1016/S0021-8502(97)00291-7

DO - 10.1016/S0021-8502(97)00291-7

M3 - Article

VL - 29

SP - 461

EP - 480

JO - Journal of Aerosol Science

JF - Journal of Aerosol Science

SN - 0021-8502

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ER -