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

    58 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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    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.",
    keywords = "energy wood, wood chips, wood fuels, combustion particles, particle emissions, particles, district heating",
    author = "O. Sippula and Jouni Hokkinen and Harri Puustinen and P. Yli-Piril{\"a} and Jorma Jokiniemi",
    year = "2009",
    doi = "10.1021/ef900098v",
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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 -