Directive 2010/75/EU of the European Parliament and of the CouncilShow full title

6. Emission limit values (mg/Nm³) for NO_x and CO for gas fired combustion plants

a Natural gas is naturally occurring methane with not more than 20 % (by volume) of inerts and other constituents.
b 75 mg/Nm3 in the following cases, where the efficiency of the gas turbine is determined at ISO base load conditions: (i) gas turbines, used in combined heat and power systems having an overall efficiency greater than 75 %; (ii) gas turbines used in combined cycle plants having an annual average overall electrical efficiency greater than 55 %; (iii) gas turbines for mechanical drives.
c For single cycle gas turbines not falling into any of the categories mentioned under note (2), but having an efficiency greater than 35 % – determined at ISO base load conditions – the emission limit value for NOx shall be 50xη/35 where η is the gas turbine efficiency at ISO base load conditions expressed as a percentage.
d 300 mg/Nm3 for such combustion plants with a total rated thermal input not exceeding 500 MW which were granted a permit before 27 November 2002 or the operators of which had submitted a complete application for a permit before that date, provided that the plant was put into operation no later than 27 November 2003.
	NOx	CO
Combustion plants firing natural gas with the exception of gas turbines and gas engines	100	100
Combustion plants firing blast furnace gas, coke oven gas or low calorific gases from gasification of refinery residues, with the exception of gas turbines and gas engines	200d	—
Combustion plants firing other gases, with the exception of gas turbines and gas engines	200d	—
Gas turbines (including CCGT), using natural gasa as fuel	50b c	100
Gas turbines (including CCGT), using other gases as fuel	120	—
Gas engines	100	100

For gas turbines (including CCGT), the NO_x and CO emission limit values set out in the table contained in this point apply only above 70 % load.

For gas turbines (including CCGT) which were granted a permit before 27 November 2002 or the operators of which had submitted a complete application for a permit before that date, provided that the plant was put into operation no later than 27 November 2003, and which do not operate more than 1 500 operating hours per year as a rolling average over a period of 5 years, the emission limit value for NO_x is 150 mg/Nm³ when firing natural gas and 200 mg/Nm³ when firing other gases or liquid fuels.

A part of a combustion plant discharging its waste gases through one or more separate flues within a common stack, and which does not operate more than 1 500 operating hours per year as a rolling average over a period of 5 years, may be subject to the emission limit values set out in the preceding paragraph in relation to the total rated thermal input of the entire combustion plant. In such cases the emissions through each of those flues shall be monitored separately.

Gas turbines and gas engines for emergency use that operate less than 500 operating hours per year are not covered by the emission limit values set out in this point. The operator of such plants shall record the used operating hours.