Division BAT 44 In order to prevent or reduce CO emissions to air from the combustion of natural gas, BAT is to ensure optimised combustion and/or to use oxidation catalysts.

United Kingdom

Table 24

BAT-associated emission levels (BAT-AELs) for NO_X emissions to air from the combustion of natural gas in gas turbines

Type of combustion plant	Combustion plant total rated thermal input(MW_th)	BAT-AELs (mg/Nm³)^f1 ^f2
These BAT-AELs also apply to the combustion of natural gas in dual-fuel-fired turbines.
In the case of a gas turbine equipped with DLN, these BAT-AELs apply only when the DLN operation is effective.
These BAT-AELs do not apply to existing plants operated < 1 500 h/yr.
Optimising the functioning of an existing technique to reduce NO_X emissions further may lead to levels of CO emissions at the higher end of the indicative range for CO emissions given after this table.
These BAT-AELs do not apply to existing turbines for mechanical drive applications or to plants operated < 500 h/yr.
For plants with a net electrical efficiency (EE) greater than 39 %, a correction factor may be applied to the higher end of the range, corresponding to [higher end] × EE/39, where EE is the net electrical energy efficiency or net mechanical energy efficiency of the plant determined at ISO baseload conditions.
The higher end of the range is 80 mg/Nm³ in the case of plants which were put into operation no later than 27 November 2003 and are operated between 500 h/yr and 1 500 h/yr.
For plants with a net electrical efficiency (EE) greater than 55 %, a correction factor may be applied to the higher end of the BAT-AEL range, corresponding to [higher end] × EE/55, where EE is the net electrical efficiency of the plant determined at ISO baseload conditions.
For existing plants put into operation no later than 7 January 2014, the higher end of the BAT-AEL range is 65 mg/Nm³.
For existing plants put into operation no later than 7 January 2014, the higher end of the BAT-AEL range is 55 mg/Nm³.
For existing plants put into operation no later than 7 January 2014, the higher end of the BAT-AEL range is 80 mg/Nm³.
The lower end of the BAT-AEL range for NO_X can be achieved with DLN burners.
These levels are indicative.
For existing plants put into operation no later than 7 January 2014, the higher end of the BAT-AEL range is 60 mg/Nm³.
For existing plants put into operation no later than 7 January 2014, the higher end of the BAT-AEL range is 65 mg/Nm³.
Type of combustion plant	Combustion plant total rated thermal input(MW_th)	Yearly average^f3 ^f4	Daily average or average over the sampling period
Open-cycle gas turbines (OCGTs)^f5 ^f6
New OCGT	≥ 50	15–35	25–50
Existing OCGT (excluding turbines for mechanical drive applications) — All but plants operated < 500 h/yr	≥ 50	15–50	25–55^f7
Combined-cycle gas turbines (CCGTs) ^f8
New CCGT	≥ 50	10–30	15–40
Existing CCGT with a net total fuel utilisation of < 75 %	≥ 600	10–40	18–50
Existing CCGT with a net total fuel utilisation of ≥ 75 %	≥ 600	10–50	18–55^f9
Existing CCGT with a net total fuel utilisation of < 75 %	50–600	10–45	35–55
Existing CCGT with a net total fuel utilisation of ≥ 75 %	50–600	25–50^f10	35–55^f11
Open- and combined-cycle gas turbines
Gas turbine put into operation no later than 27 November 2003, or existing gas turbine for emergency use and operated < 500 h/yr	≥ 50	No BAT-AEL	60–140^f12 ^f13
Existing gas turbine for mechanical drive applications — All but plants operated < 500 h/yr	≥ 50	15–50^f14	25–55^f15

As an indication, the yearly average CO emission levels for each type of existing combustion plant operated ≥ 1 500 h/yr and for each type of new combustion plant will generally be as follows:

New OCGT of ≥ 50 MW_th: < 5–40 mg/Nm³. For plants with a net electrical efficiency (EE) greater than 39 %, a correction factor may be applied to the higher end of this range, corresponding to [higher end] × EE/39, where EE is the net electrical energy efficiency or net mechanical energy efficiency of the plant determined at ISO baseload conditions.
Existing OCGT of ≥ 50 MW_th (excluding turbines for mechanical drive applications): < 5–40 mg/Nm³. The higher end of this range will generally be 80 mg/Nm³ in the case of existing plants that cannot be fitted with dry techniques for NO_X reduction, or 50 mg/Nm³ for plants that operate at low load.
New CCGT of ≥ 50 MW_th: < 5–30 mg/Nm³. For plants with a net electrical efficiency (EE) greater than 55 %, a correction factor may be applied to the higher end of the range, corresponding to [higher end] × EE/55, where EE is the net electrical energy efficiency of the plant determined at ISO baseload conditions.
Existing CCGT of ≥ 50 MW_th: < 5–30 mg/Nm³. The higher end of this range will generally be 50 mg/Nm³ for plants that operate at low load.
Existing gas turbines of ≥ 50 MW_th for mechanical drive applications: < 5–40 mg/Nm³. The higher end of the range will generally be 50 mg/Nm³ when plants operate at low load.

In the case of a gas turbine equipped with DLN burners, these indicative levels correspond to when the DLN operation is effective.

Table 25

BAT-associated emission levels (BAT-AELs) for NO_X emissions to air from the combustion of natural gas in boilers and engines

Type of combustion plant	BAT-AELs (mg/Nm³)
Optimising the functioning of an existing technique to reduce NO_X emissions further may lead to levels of CO emissions at the higher end of the indicative range for CO emissions given after this table.
These BAT-AELs do not apply to plants operated < 1 500 h/yr.
For plants operated < 500 h/yr, these levels are indicative.
These BAT-AELs only apply to spark-ignited and dual-fuel engines. They do not apply to gas-diesel engines.
In the case of engines for emergency use operated < 500 h/yr that could not apply the lean-burn concept or use SCR, the higher end of the indicative range is 175 mg/Nm³.
	Yearly average^f16		Daily average or average over the sampling period
	New plant	Existing plant^f17	New plant	Existing plant^f18
Boiler	10–60	50–100	30–85	85–110
Engine^f19	20–75	20–100	55–85	55–110^f20

As an indication, the yearly average CO emission levels will generally be:

< 5–40 mg/Nm³ for existing boilers operated ≥ 1 500 h/yr,
< 5–15 mg/Nm³ for new boilers,
30–100 mg/Nm³ for existing engines operated ≥ 1 500 h/yr and for new engines.

Description

Annotations

Footnotes

f1: These BAT-AELs also apply to the combustion of natural gas in dual-fuel-fired turbines.
f2: In the case of a gas turbine equipped with DLN, these BAT-AELs apply only when the DLN operation is effective.
f3: These BAT-AELs do not apply to existing plants operated < 1 500 h/yr.
f4: Optimising the functioning of an existing technique to reduce NO_X emissions further may lead to levels of CO emissions at the higher end of the indicative range for CO emissions given after this table.
f5: These BAT-AELs do not apply to existing turbines for mechanical drive applications or to plants operated < 500 h/yr.
f6: For plants with a net electrical efficiency (EE) greater than 39 %, a correction factor may be applied to the higher end of the range, corresponding to [higher end] × EE/39, where EE is the net electrical energy efficiency or net mechanical energy efficiency of the plant determined at ISO baseload conditions.
f7: The higher end of the range is 80 mg/Nm³ in the case of plants which were put into operation no later than 27 November 2003 and are operated between 500 h/yr and 1 500 h/yr.
f8: For plants with a net electrical efficiency (EE) greater than 55 %, a correction factor may be applied to the higher end of the BAT-AEL range, corresponding to [higher end] × EE/55, where EE is the net electrical efficiency of the plant determined at ISO baseload conditions.
f9: For existing plants put into operation no later than 7 January 2014, the higher end of the BAT-AEL range is 65 mg/Nm³.
f10: For existing plants put into operation no later than 7 January 2014, the higher end of the BAT-AEL range is 55 mg/Nm³.
f11: For existing plants put into operation no later than 7 January 2014, the higher end of the BAT-AEL range is 80 mg/Nm³.
f12: The lower end of the BAT-AEL range for NO_X can be achieved with DLN burners.
f13: These levels are indicative.
f14: For existing plants put into operation no later than 7 January 2014, the higher end of the BAT-AEL range is 60 mg/Nm³.
f15: For existing plants put into operation no later than 7 January 2014, the higher end of the BAT-AEL range is 65 mg/Nm³.
f16: Optimising the functioning of an existing technique to reduce NO_X emissions further may lead to levels of CO emissions at the higher end of the indicative range for CO emissions given after this table.
f17: These BAT-AELs do not apply to plants operated < 1 500 h/yr.
f18: For plants operated < 500 h/yr, these levels are indicative.
f19: These BAT-AELs only apply to spark-ignited and dual-fuel engines. They do not apply to gas-diesel engines.
f20: In the case of engines for emergency use operated < 500 h/yr that could not apply the lean-burn concept or use SCR, the higher end of the indicative range is 175 mg/Nm³.