Germany: Stationary Engines
Background
Emissions from stationary engines in Germany are controlled by the TA Luft regulation introduced in 1986 and later by the 44th BImSchV introduced in 2019.The Technische Anleitung zur Reinhaltung der Luft, in short referred to as TA Luft, is a regulation covering air quality requirements—including emissions, ambient exposures and their control methods—applicable to a number of pollutants from a range of stationary sources. The TA Luft regulation, based on the “Federal Air Pollution Control Act” (“Bundes-Immissionsschutzgesetz”), was introduced and enforced by the German Environment Ministry BMU (Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit).
Among other sources, the TA Luft regulation covers emissions of pollutants from stationary internal combustion engines. The TA Luft requirements have been widely applied to stationary gas and diesel engines not only in Germany, but also in several other European markets.
The most recent revision of the TA Luft regulation, known as TA Luft 2002, was adopted on July 24, 2002. Compared to the previous requirements, TA Luft 2002 introduced more stringent emission limits for particulate matter, sulfur oxides, and nitrogen oxides from internal combustion engines.
On June 20, 2019, updated emissions standards previously covered by TA Luft 2002 entered into force with the publication of 44. Verordnung zur Durchführung des Bundes-Immissionsschutzgesetzes (Verordnung über mittelgroße Feuerungs-, Gasturbinen- und Verbrennungsmotoranlagen)—44th BImSchV. While this incorporated EU Directive 2015/2193 (Medium Combustion Plant Directive, MCPD) into German law, 44th BImSchV included more stringent emission limits as well as limits on pollutants such as CO, NH3 and formaldehyde not included in the EU MCPD. Due to delays in finalization of the legislation, some of the 44th BImSchV requirements apply retroactively. The 44th BImSchV requirements apply to new plants while TA Luft 2002 requirements continue to apply to existing sources until the end of 2024.
Engine Emission Standards
TA Luft 2002 and 44th BImSchV emission limits are given in the following tables [4701][4700]. Different limits exist for compression ignition (CI) and for spark ignited (SI) engines. Gas fueled CI engines (dual fuel with diesel pilot ignition) often enjoy more relaxed limits, especially if fueled by biogas (such as sewage or landfill gas). It should be noted that the concentration values in the tables are at 5% O2 while those for the EU’s MCPD are at 15% O2.
Under the 44th BImSCHv, existing installations are those that: (1) were put into service before December 20, 2018 or (2) were approved under the Federal Emission Control Act (Bundes-Immissionsschutzgesetz) and put into service by December 20, 2018. Installations to which the above definition does not apply are regarded as new installations. The 44th BImSchV limits apply to new installations according to the above dates and to exiting installations starting January 2025 unless otherwise noted.
| Gaseous Fuel | Engine Type | Power | COe | NOxe | SOxa,e | HCHO | TDa | TCe | NH3d | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MWth | g/Nm3 | g/Nm3 | mg/Nm3 | mg/Nm3 | mg/Nm3 | g/Nm3 | mg/Nm3 | |||||||||||
| TAL | BIm | TAL | BIm | TAL | BIm | TAL | BIm | TAL | BIm | TAL | BImf | TAL | BIm | TAL | BIm | TAL | BIm | |
| Natural gas | Lean burn | - | - | 0.30 | 0.25 | 0.50 | New: 0.25 0.1 from 2025 Existing: 0.1 from 2029 |
9 | 9 | 60 | New: 30b 20 from 2020 Existing: 30b,c |
New & existing: 1.3 from 2025 |
30 | |||||
| Other | 0.25 | New & existing, λ=1: 0.3 from 2025 |
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| Mine gas | Lean burn | 0.65 | 0.50 | 0.50 | 0.50 | 31 | 31 | 60 | 9 | New & existing: 1.3 from 2025 |
30 | |||||||
| Other | 0.25 | |||||||||||||||||
| Biogas | Pilot injection | - | <3 | - | 2.0 | 0.50 | 1 | New: 0.50g 0.1 from 2023 Existing: 0.1 from 2029 |
310 | 89 | 40 | New: 1.3 from 2023 Existing: 0.3 from 2029 |
30 | |||||
| ≥3 | 0.65 | 0.50 | 40 | |||||||||||||||
| Spark ignition | <3 | 1.0 | 0.50 | 60 | ||||||||||||||
| ≥3 | 0.65 | 0.50 | 60 | |||||||||||||||
| Sewage gas | Pilot injection | - | <3 | - | 2.0 | 0.50 | 1 | 0.50 | 310 | 89 | 60 | New & existing: 1.3 from 2025 |
30 | |||||
| ≥3 | 0.65 | 0.50 | 60 | |||||||||||||||
| Spark ignition | <3 | 1.0 | 0.50 | 60 | ||||||||||||||
| ≥3 | 0.65 | 0.25 | 60 | |||||||||||||||
| Landfill gas | Lean burn | - | - | 0.65 | 0.65 | 0.50 | 310 | New: 31 Existing: 31; 310 for P<1 MWth |
60 | New: 60b 40 from 2025 Existing: 40 |
9 | 30 | ||||||
| Other | 0.25 | 60 | ||||||||||||||||
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a - these limit values are specified in the 44th BImSchV with 3% reference oxygen and are converted to 5% in this table b - applies to spark-ignition or lean-burn engines; a limit value of 5 mg/m3 applies to other engines c - if formaldehyde emissions of up to 40 mg/m3 were measured during the last emission measurement before 05.12.2016, the limit values must be complied with from 05.02.2019 d - for engines using selective catalytic or selective non-catalytic reduction e - limits do not apply to emergency engines or engines used for peak shaving for less than 300 h/y f - for emergency only engines, a limit of 60 mg/m3 applies g - limit applies to biogas engines operating < 300 h/y |
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| Liquid Fuel | Power | COb | NOxb | HCHO | TD | NH3d | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MWth | g/Nm3 | g/Nm3 | mg/Nm3 | mg/Nm3 | mg/Nm3 | |||||||
| TAL | BIm | TAL | BIm | TAL | BIm | TAL | BIm | TAL | BIm | TAL | BIm | |
| Diesel, light fuel oil, ethanol, methanol, etc. |
<3 | - | 0.3 | 0.3 | 1 | 0.1 | 60 | 20/60c | 20/80a | 20/50a | - | 30 |
| ≥3 | - | 0.5 | ||||||||||
|
a - higher value applies to engines used for emergency operation only or peak shaving operation for less than 300 h/y b - limits do not apply to emergency engines or engines used for peak shaving for less than 300 h/y c - higher value applies to engines used for emergency operation only d - for engines using selective catalytic or selective non-catalytic reduction |
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The following apply to engines subject to the 44th BImSchV and used exclusively for emergency operation or operated no more than 300 h/year (peak shaving operation) [4700]:
- For new liquid fueled engines, a DPF is mandatory with particulate emissions limited to 5 mg/m3 unless particulate emissions are less than 50 mg/m3
- For existing liquid fueled engines, a DPF is not required but particulate emissions must be less than 80 mg/m3
- CO emissions are not controlled but state of the art measures must be used to limit emissions
- Only for engines used exclusively only for emergency operation (not engines used < 300 h/y), the formaldehyde limit is 60 mg/m3
- NOx emissions are not controlled for engines using liquid fuels, biogas, natural gas and LPG but state of the art measures must be used to limit emissions
- NOx emissions from biogas engines operated < 300 h/y (not those used exclusively for emergency operation), are limited to 0.50 g/m3
- SOx and total carbon emissions are not limited
Consistent with the EU’s MCPD, the 44th BImSchV has an emission monitoring requirement. In most cases, this requires measurements once a year or once every 3 years depending on the fuel used and the particular emission component. However, NOx and NH3 emissions must be continuously monitored. Monitoring of NH3 is not required if an ammonia slip catalyst (ASC) is used.
All of the above engine emission limits are expressed as dry gas concentrations at STP conditions, that have been corrected to a 5% oxygen content using the following formula:
EB = EM × (21 - OB)/(21 - OM) (1)
where:
EB - mass concentration of pollutant corrected for the reference O2 concentration,
EM - measured mass concentration of pollutant,
OB - reference O2 concentration, vol. %,
OM - measured O2 concentration, vol. %.
The TA Luft 2002 limits for diesel engines are rather strict. The NOx limit of 0.5 g/Nm3 typically requires the use of SCR catalysts on large diesel engines.
Sulfur Regulations. According to TA Luft 2002, a liquid fired stationary engine is to burn a light fuel oil according to DIN 51603 Part 1 (March 1998) containing max. 0.2% (wt.) sulfur and with a lower heating value > 42.6 MJ/kg, or to reach an equivalent SO2 limit by installing a flue gas desulfurization unit. The equivalent SO2 limit resulting from the above fuel requirement is about 110 mg/Nm3 @ 15% O2 = approx. 300 mg/Nm3 @ 5% O2. The TA Luft 2002 sulfur limits no longer apply to either new or existing installations.
Only the following liquid petroleum fuels may be used in stationary diesel engines: heating oils according to DIN 51603 Part 1 (petroleum fuels) or Part 6 (petroleum fuels/renewable fuel blends), March 2017 edition, with a maximum sulfur content of 0.1% mass or diesel fuels according to EN 590 with a maximum sulfur content of 10 mg/kg. Requirements for gaseous fuels are also covered by the regulations [4701][4702].