Small combustion plants
Small combustion plants are usually operated with fossil fuels such as natural gas, heating oil, coal or wood . They are designed for private use and small businesses.
According to the 1st BImSchV (Ordinance on Small and Medium-Sized Combustion Plants), all plants with a rated thermal input of less than 1000 kW are considered small combustion plants.
Nowadays, these mostly include oil heating systems, gas boilers and condensing boilers. Pellet heating systems and wood chip heating systems that run on wood are also gaining in popularity. However, burning wood can lead to harmful air pollution with dioxins and particulate matter.
Dioxins – harmful to the environment and carcinogenic
Dioxins are two groups of chemically similar, chlorinated organic compounds that belong to the oxygenated derivatives of halogenated hydrocarbons. Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF) are each assigned to one of these groups. Even in small quantities, dioxinsand furans can cause cancer.
Dioxins can be produced asharmful by-products in processes such as waste incineration, in the metal industry or through private use of fireplaces and can be released into the air. Natural processes such as forest fires and volcanic eruptions can also produce dioxins. The majority of these harmful substances come from human processes, in particular from illegal waste incineration in the garden or fireplace.
Small combustion plants – air pollution from fine dust
According to data from the “National Emissions Inventory for Air Pollutants, Submission 2023“, particulate matter emissions from all small combustion plants such as oil, gas, coal and wood amount to around 21.3 thousand tons. Wood firing systems such as wood boilers and single-room firing systems are particularly significant here, emitting around 19.4 thousand tons. The total emissions of particulate matter from small combustion plants exceed those from road traffic. Wood combustion, in particular, accounts for 97 percent of harmful particulate matter. Particularly dangerous are the respirable particles in fine dust, which can cause respiratory and lung problems and even cancer. The E-dust fraction comprises particles with such a small diameter that they can enter the respiratory tract.
Nitrogen oxide emissions from small combustion plants
In 2021, emissions of nitrogen oxides from small combustion plants accounted for around 75 thousand tons, or around 8 % of total emissions in Germany (National Emissions Inventory for Air Pollutants, Submission 2023).
Carbon dioxide emissions from small combustion plants
At 114.0 million tons, carbon dioxide emissions from fossil fuels (heating oil, natural gas, coal) from small combustion plants were slightly lower in 2021 than in the previous year (National Greenhouse Gas Inventory, submission 2023).
Operation of small combustion plants in accordance with 1 BImSchV
The 1st BImSchV (Ordinance on Small and Medium-Sized Combustion Plants) regulates the operation of combustion plants that are not subject to approval in accordance with § 4 BImSchG. This ordinance applies in particular to small combustion plants in the domestic sector and for small businesses. The aim is to further reduce emissions from small combustion plants.
In particular, the 1st BImSchV contains requirements for:
- permissible fuels for various systems such as boilers for wood and coal, wood-burning stoves, tiled stoves, stoves and open fires.
- Conditions for the installation and operation of gas, oil, coal or wood heating systems
- defined limit values for pollutant emissions
- Monitoring frequency and scope for reasons of immission control
- List of fuels that may be burned in certain installations, including oil, gas, coal, briquettes, wood and straw
The 1st BImSchV is intended to help significantly reduce dust emissions from small wood-burning systems in order to protect people’s health. Odour nuisance is also to be minimized. In particular, the 1st BImSchV is intended to support municipalities and cities in complying with the legal requirements for maximum particulate matter pollution .
Limit values for small and medium-sized combustion plants
Limit values for individual firing systems
For stoves that primarily heat the room in which they are located, i.e. for single-room firing systems, limit values apply for the emission of carbon monoxide and dust as well as a minimum requirement for the efficiency. Compliance with these values is verified in a type test before an appliance type is launched on the market.
Limit values for boilers
For smaller boilers, from four kilowatts (kW), the emission limit values and their monitoring obligations depend on the year in which they were installed. If very high emissions are produced when operating old stoves and boilers, operators are obliged to retrofit these appliances or shut them down after certain transitional periods.
Limit values for combustion plants built in 2015
Specific emission limits apply to combustion plants built from 2015 onwards. These can only be complied with using modern technologies.
Measuring air pollutants with GSA measuring devices PM4-2
The GSA measuring device PM 4-2 (license IFA, St. Augustin) is suitable for measuring dust fractions such as A-dust (total dust) or the finer and particularly harmful E-dust (inhalable dust) in accordance with EN 481. The PM 4-2 measuring devices can be used flexibly at various locations, including mobile workplaces.
It can also be operated independently of themains . A high, adjustable air flow rate of up to 4 m³/h enables precise measurements. With the PM 4-2 can be used to detect polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDD/PCDF) in addition to sampling dust fractions such as A-dust and E-dust. Depending on the measurement purpose, the appropriate sampling head must be connected to the basic device to carry out the measurement.
Sources:
Image source: 123rf.com © dolgachov, image no. 51852097
www.bmuv.de/faqs/kleinfeuerungsanlagen/
www.gesetze-im-internet.de/bimschv_1_2010/
www.umweltbundesamt.de/sites/default/files/medien/384/bilder/dateien/2_abb_pm10-emi-kfa_2023-04-13.pdf
www.umweltbundesamt.de/daten/luft/emissionsminderung-bei-kleinfeuerungsanlagen#anforderungen-an-holzfeuerungsanlagen
www.umweltbundesamt.de/daten/luft/emissionsminderung-bei-kleinfeuerungsanlagen#emissionen-unterschiedlicher-feuerungssysteme
www.umweltbundesamt.de/themen/chemikalien/persistente-organische-schadstoffe-pop/dioxine-pcddpcdf-polychlorierte-biphenyle-pcb
en.wikipedia.org/wiki/Polychlorinated_dibenzodioxins_and_dibenzofurans
en.wikipedia.org/wiki/E-dust
en.wikipedia.org/wiki/Small combustion plant
en.wikipedia.org/wiki/woodchip-heating
en.wikipedia.org/wiki/pellet heating
en.wikipedia.org/wiki/Verordnung_über_kleine_und_mittlere_Feuerungsanlagen