Particle emissions from small wood-fired district heating units

O. Sippula (Corresponding Author), Jouni Hokkinen, Harri Puustinen, P. Yli-Pirilä, Jorma Jokiniemi

Research output: Contribution to journalArticleScientificpeer-review

57 Citations (Scopus)

Abstract

Particle and gaseous emissions of four different wood chip-fired district heating units in the size range 5−15 MW were studied. Three of the units were fire-tube boilers based on rotating grate combustion technology, and one was a gasification combustion boiler. All of the units were equipped with cyclones to remove coarse particles from the flue gas. In addition, two of the rotating grate boilers were equipped with single field electrostatic precipitators (ESP), and one with a condensing flue gas scrubber. The particle filtration efficiencies of these particle removal appliances were measured. The grate boilers produced on average 211−483 mg/MJ of total suspended particles (TSP) and 55−92 mg/MJ of fine particles (PM1) upstream of the secondary particle filters. These levels of TSP and PM1 were clearly higher than those produced by the gasification combustion boiler (on average 50 mg/MJ TSP and 13 mg/MJ PM1). The ESPs were found to remove around 95% of the PM1s and 93% of TSP, leading to relatively low particle emissions. The lowest collection efficiency (for particles below 10 μm) was achieved in the size range 0.2−1 μm. The condensing flue gas scrubber removed on average 44% of PM1 and 84% of TSP. In all of the plants, the fine particles mainly consisted of potassium salts. In addition, they contained small amounts of organic material and various metals, of which zinc was the most abundant. In general, the study shows that small (<20 MW) biomass-fired boilers, not equipped with effective particle filters, are an important source of fine particles introduced into ambient air and they have a high potential for reducing the emissions with currently available flue gas cleaning technology.
Original languageEnglish
Pages (from-to)2974-2982
Number of pages9
JournalEnergy & Fuels
Volume23
Issue number6
DOIs
Publication statusPublished - 2009
MoE publication typeA1 Journal article-refereed

Fingerprint

District heating
Boilers
Wood
Flue gases
Scrubbers
Gasification
Fire tube boilers
Electrostatic precipitators
Gas emissions
Potassium
Zinc
Cleaning
Biomass
Salts
Metals
Air

Keywords

  • energy wood
  • wood chips
  • wood fuels
  • combustion particles
  • particle emissions
  • particles
  • district heating

Cite this

Sippula, O., Hokkinen, J., Puustinen, H., Yli-Pirilä, P., & Jokiniemi, J. (2009). Particle emissions from small wood-fired district heating units. Energy & Fuels, 23(6), 2974-2982. https://doi.org/10.1021/ef900098v
Sippula, O. ; Hokkinen, Jouni ; Puustinen, Harri ; Yli-Pirilä, P. ; Jokiniemi, Jorma. / Particle emissions from small wood-fired district heating units. In: Energy & Fuels. 2009 ; Vol. 23, No. 6. pp. 2974-2982.
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Sippula, O, Hokkinen, J, Puustinen, H, Yli-Pirilä, P & Jokiniemi, J 2009, 'Particle emissions from small wood-fired district heating units', Energy & Fuels, vol. 23, no. 6, pp. 2974-2982. https://doi.org/10.1021/ef900098v

Particle emissions from small wood-fired district heating units. / Sippula, O. (Corresponding Author); Hokkinen, Jouni; Puustinen, Harri; Yli-Pirilä, P.; Jokiniemi, Jorma.

In: Energy & Fuels, Vol. 23, No. 6, 2009, p. 2974-2982.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Particle emissions from small wood-fired district heating units

AU - Sippula, O.

AU - Hokkinen, Jouni

AU - Puustinen, Harri

AU - Yli-Pirilä, P.

AU - Jokiniemi, Jorma

PY - 2009

Y1 - 2009

N2 - Particle and gaseous emissions of four different wood chip-fired district heating units in the size range 5−15 MW were studied. Three of the units were fire-tube boilers based on rotating grate combustion technology, and one was a gasification combustion boiler. All of the units were equipped with cyclones to remove coarse particles from the flue gas. In addition, two of the rotating grate boilers were equipped with single field electrostatic precipitators (ESP), and one with a condensing flue gas scrubber. The particle filtration efficiencies of these particle removal appliances were measured. The grate boilers produced on average 211−483 mg/MJ of total suspended particles (TSP) and 55−92 mg/MJ of fine particles (PM1) upstream of the secondary particle filters. These levels of TSP and PM1 were clearly higher than those produced by the gasification combustion boiler (on average 50 mg/MJ TSP and 13 mg/MJ PM1). The ESPs were found to remove around 95% of the PM1s and 93% of TSP, leading to relatively low particle emissions. The lowest collection efficiency (for particles below 10 μm) was achieved in the size range 0.2−1 μm. The condensing flue gas scrubber removed on average 44% of PM1 and 84% of TSP. In all of the plants, the fine particles mainly consisted of potassium salts. In addition, they contained small amounts of organic material and various metals, of which zinc was the most abundant. In general, the study shows that small (<20 MW) biomass-fired boilers, not equipped with effective particle filters, are an important source of fine particles introduced into ambient air and they have a high potential for reducing the emissions with currently available flue gas cleaning technology.

AB - Particle and gaseous emissions of four different wood chip-fired district heating units in the size range 5−15 MW were studied. Three of the units were fire-tube boilers based on rotating grate combustion technology, and one was a gasification combustion boiler. All of the units were equipped with cyclones to remove coarse particles from the flue gas. In addition, two of the rotating grate boilers were equipped with single field electrostatic precipitators (ESP), and one with a condensing flue gas scrubber. The particle filtration efficiencies of these particle removal appliances were measured. The grate boilers produced on average 211−483 mg/MJ of total suspended particles (TSP) and 55−92 mg/MJ of fine particles (PM1) upstream of the secondary particle filters. These levels of TSP and PM1 were clearly higher than those produced by the gasification combustion boiler (on average 50 mg/MJ TSP and 13 mg/MJ PM1). The ESPs were found to remove around 95% of the PM1s and 93% of TSP, leading to relatively low particle emissions. The lowest collection efficiency (for particles below 10 μm) was achieved in the size range 0.2−1 μm. The condensing flue gas scrubber removed on average 44% of PM1 and 84% of TSP. In all of the plants, the fine particles mainly consisted of potassium salts. In addition, they contained small amounts of organic material and various metals, of which zinc was the most abundant. In general, the study shows that small (<20 MW) biomass-fired boilers, not equipped with effective particle filters, are an important source of fine particles introduced into ambient air and they have a high potential for reducing the emissions with currently available flue gas cleaning technology.

KW - energy wood

KW - wood chips

KW - wood fuels

KW - combustion particles

KW - particle emissions

KW - particles

KW - district heating

U2 - 10.1021/ef900098v

DO - 10.1021/ef900098v

M3 - Article

VL - 23

SP - 2974

EP - 2982

JO - Energy & Fuels

JF - Energy & Fuels

SN - 0887-0624

IS - 6

ER -