Division BAT 42 In order to prevent or reduce NOX emissions to air from the combustion of natural gas in gas turbines, BAT is to use one or a combination of the techniques given below.
United Kingdom
| Technique | Description | Applicability | |
|---|---|---|---|
| a. | Advanced control system | See description in Section 8.3. This technique is often used in combination with other techniques or may be used alone for combustion plants operated < 500 h/yr | The applicability to old combustion plants may be constrained by the need to retrofit the combustion system and/or control command system |
| b. | Water/steam addition | See description in Section 8.3 | The applicability may be limited due to water availability |
| c. | Dry low-NOX burners (DLN) | The applicability may be limited in the case of turbines where a retrofit package is not available or when water/steam addition systems are installed | |
| d. | Low-load design concept | Adaptation of the process control and related equipment to maintain good combustion efficiency when the demand in energy varies, e.g. by improving the inlet airflow control capability or by splitting the combustion process into decoupled combustion stages | The applicability may be limited by the gas turbine design |
| e. | Low-NOX burners (LNB) | See description in Section 8.3 | Generally applicable to supplementary firing for heat recovery steam generators (HRSGs) in the case of combined-cycle gas turbine (CCGT) combustion plants |
| f. | Selective catalytic reduction (SCR) | Not applicable in the case of combustion plants operated < 500 h/yr. Not generally applicable to existing combustion plants of < 100 MWth. Retrofitting existing combustion plants may be constrained by the availability of sufficient space. There may be technical and economic restrictions for retrofitting existing combustion plants operated between 500 h/yr and 1 500 h/yr | |