Archived: Proposed guidelines: reducing nitrogen oxide emissions from stationary combustion turbines: chapter 4

4. NO_x Emission Limits

4.1. These Guidelines recommend NO_x emission limits for combustion turbines. These limits can be met using one of the following methods:

1. the output-based method; or
2. the concentration-based method.

4.2. The NO_x emission limits in tables 1 and table2 are a function of turbine application and power rating (expressed in MW). These limits do not apply during start-up periods and shut-down periods, during periods of part-load operation or when the ambient temperature at the point of air intake is less than -18°C.

4.3. Output-based method

Under the output-based method, limits are expressed as emission intensity (mass of NO_x per unit output of shaft or electrical energy). To conform with these Guidelines, an operator should meet the applicable emission limit mentioned in Table 1. The NO_x emission limits take into consideration the quantity of energy produced by the combustion turbine, calculated in gigajoules (GJ), as well as the emissions, calculated in grams (g) of NO_x.

4.4. Concentration-based method

Under the concentration-based method, emission limits are expressed as concentration of NO_x. If this method is chosen, the concentration of NO_x at the combustion turbine exhaust should not exceed the limit set out in Table 2.