Source: English Handbook for Wood Pellet Combustion,. Page 7. 7. Biomass
combustion steps (2). Source: The Handbook of Biomass Combustion and
Cofiring ...
RigaTehniskā Technicaluniversitāte University Rīgas Faculty of Energy and Electrical Engineering Enerģētikas un elektrotehnikas fakultāte I tit f Energy Eīb un Systems S siltuma t and Environment E i institūts VidInstitute Vides aizsardzības i t ofd ilt sistēmu i dtē i titūtt www.videszinatne.lv www.videszinatne.lv
Energy Efficient and Ecological Housing (ECOHOUSING) Biomass combustion processes Aivars Žandeckis, Ph.D., researcher and lecturer
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Topics
Biomass conversion technologies Combustion process Combustion products Secrets of g good combustion Problems and probable reasons
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Biomass conversion technologies
Source: R.Fakhrai, KTH
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Biomass conversion technologies g
Source: Renewable Energies and CO2, 2012
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Stage g of development p
Source: Renewable Energies and CO2, 2012
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Biomass combustion steps (1)
Source: English Handbook for Wood Pellet Combustion,
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Biomass combustion steps (2)
Source: The Handbook of Biomass Combustion and Cofiring
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Combustion air
Source: English Handbook for Wood Pellet Combustion,
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Biomass fuel and combustion products
Source: English Handbook for Wood Pellet Combustion,
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Please name harmful emissions from biofuel combustion
CO (carbon monoxide) NOx (nitric oxides) SOx (sulphur oxides) PAH ((polycyclic l li aromatic i h hydrocarbons) d b ) TOC (total organic compounds) Dust (PM or particle matter)
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Comparison of CO2 emissions, g/MJ
Source: English Handbook for Wood Pellet Combustion, Institute of Energy Systems and Environment
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Comparison of CO emissions, mg/MJ
Source: English Handbook for Wood Pellet Combustion,
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Comparison of SO2 emissions, g/MJ
Source: English Handbook for Wood Pellet Combustion
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Comparison of NOx emissions, mg/MJ
Source: English Handbook for Wood Pellet Combustion,
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Comparison of TOC emissions, mg/MJ
Source: English Handbook for Wood Pellet Combustion,
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Comparison of dust emissions, mg/Nm3
Source: English Handbook for Wood Pellet Combustion
Fundamentals for good combustion (1) Effective mixing of fuel and combustion air in proper amounts
Source: Environmental Monitoring laboratory, RTU
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Fundamentals for good combustion (2) High temperature environment in the combustion chamber for the combustion p process to p proceed
Source: Environmental Monitoring laboratory, RTU
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Fundamentals for good combustion (3) Well organised system for ash removal
Source: Environmental Monitoring laboratory, RTU
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Problems and probable reasons A lot of ash in the boiler
Slagging in the boiler
→ fuel contains biomass with high ash content (bark, seed residues, leaves, needles etc.) → biomass is contaminated with sand & dirt → contains waste products → fuel contains biomass with low melting lti ttemperature t (bark, (b k seed d residues, leaves, needles etc.) → biomass is contaminated with sand & dirt → contains waste products → not proper technology
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Problems and probable reasons
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Deposits and corrosion → fuel contains “not clean” biomass, high content of sulphur & chlorine → contains waste products Poor combustion → too high content of dust → too t high hi h moisture i t content t t → air supply is too low
Visual combustion control: smoke None, or only quite thin, visible smoke White smoke, that quickly di disappears iin open air i
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Good combustion with a sustainable pp y of air supply The smoke contains water vapour from ffuel el moisture moist re
Visible greyish or dark smoke. Can occur visible carbon particles
The smoke contains ash particles. Can be controlled through the primary and secondary air supply. Possibly the air speed is too high through the boiler
Thick, dark smoke with a smell of tar
Bad combustion with high amount of un-burnt carbon. Ensure that the air supply l fit fits th the amountt off fuel f l being b i burned Source: English Handbook for Wood Pellet Combustion,
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Contacts Riga Technical University Institute of Energy Systems & Environment K Kronvalda ld b boul. l 1 1, Riga, Ri L Latvia t i www.videszinatne.lv Aivars Žandeckis Ž
[email protected] +37167089943
