# Commission Implementing Decision (EU) 2017/1442 of 31 July 2017 establishing best available techniques (BAT) conclusions, under Directive 2010/75/EU of the European Parliament and of the Council, for large combustion plants (notified under document C(2017) 5225) (Text with EEA relevance), Division BAT 56: In order to prevent or reduce NOX emissions to air while limiting CO emissions to air from the combustion of process fuels from the chemical industry, BAT is to use one or a combination of the techniques given below.

Extent: E+W+S+N.I.

Technique
Description
Applicability
a.
Low-NOX burners (LNB)
See descriptions in Section 8.3
Generally applicable
b.
Air staging
c.
Fuel staging
See description in Section 8.3.
Applying fuel staging when using liquid fuel mixtures may require a specific burner design
d.
Flue-gas recirculation
See descriptions in Section 8.3
Generally applicable to new combustion plants.
Applicable to existing combustion plants within the constraints associated with chemical installation safety
e.
Water/steam addition
The applicability may be limited due to water availability
f.
Fuel choice
Applicable within the constraints associated with the availability of different types of fuel and/or an alternative use of the process fuel
g.
Advanced control system
The applicability to old combustion plants may be constrained by the need to retrofit the combustion system and/or control command system
h.
Selective non-catalytic reduction (SNCR)
Applicable to existing combustion plants within the constraints associated with chemical installation safety.
Not applicable to combustion plants operated < 500 h/yr.
The applicability may be limited in the case of combustion plants operated between 500 h/yr and 1 500 h/yr with frequent fuel changes and frequent load variations
i.
Selective catalytic reduction (SCR)
Applicable to existing combustion plants within the constraints associated with duct configuration, space availability and chemical installation safety.
Not applicable to combustion plants operated < 500 h/yr.
There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500 h/yr.
Not generally applicable to combustion plants of < 100 MWth
Table 34
BAT-associated emission levels (BAT-AELs) for NOX emissions to air from the combustion of 100 % process fuels from the chemical industry in boilers
For plants operated < 1 500 h/yr, these BAT AELs do not apply.
For plants operated < 500 h/yr, these levels are indicative.
For existing plants of ≤ 500 MWth put into operation no later than 27 November 2003 using liquid fuels with a nitrogen content higher than 0,6 wt-%, the higher end of the BAT-AEL range is 380 mg/Nm3.
For existing plants put into operation no later than 7 January 2014, the higher end of the BAT-AEL range is 180 mg/Nm3.
For existing plants put into operation no later than 7 January 2014, the higher end of the BAT-AEL range is 210 mg/Nm3.
Fuel phase used in the combustion plant
BAT-AELs (mg/Nm3)
Yearly average
Daily average or average over the sampling period
New plant
Existing plant
New plant
Existing plant
Mixture of gases and liquids
30–85
80–290
50–110
100–330
Gases only
20–80
70–100
30–100
85–110
As an indication, the yearly average CO emission levels for existing plants operated ≥ 1 500 h/yr and for new plants will generally be < 5–30 mg/Nm3.

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Source: https://www.legislation.gov.uk/eudn/2017/1442/annex/division/5/division/5.1/division/5.1.3/division/1 (the official version)
Page: https://openlegislation.uk/eu-decision-2017-1442/annex/division-5/division-5.1/division-5.1.3/division-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.