Establishing factors that influence NOx reduction at waste incineration plant to levels below the upper end of the BAT-AEL`s

Tender description

Waste Incineration plant operating in the UK are required to meet the BAT AEL`s prescribed in the in the BAT conclusions for the Waste Incineration BREF by December 2023. BAT AEL`s are specified as a range and operators of Incineration plant are expected to be able to comply with the top of that range as a minimum. The Environment Agency's policy on setting ELVs in permits in response to BATCs is based on Defra Part A EPR guidance which requires the upper end of the range to be set, unless the operator proposes a lower limit or the local environment requires it. However, this is likely to change in the near future, meaning that lower ELVs could be set for certain pollutants. BAT 29 of Waste Incineration BREF BAT Conclusions (BATCs) prescribes a BAT-AEL range for NOx (a priority pollutant in the UK) for existing plants of 50-150 mg/Nm3 (where the upper end of the range is 180 where SCR is not applicable) and 50-120 mg/Nm3 for new plants. It may be possible for existing (and new) incineration plants to further decrease their emissions beyond the top end of the BAT-AEL range by increased ammonia injection within their SNCR systems, and in some cases the use of SCR or catalytic bag filters at new plants. However, this may have cross-media impacts including increased ammonia (also a priority pollutant) and nitrous oxide (greenhouse gas) emissions, and SCR reduces plant efficiency, thereby increasing global warming potential. The Environment Agency wants to further develop its understanding of the costs and cross-media impacts of requiring new and existing incinerators to meet lower NOx limits, which will in turn help inform its regulatory approach and ensure it strikes the right balance between minimising NOx while not significantly increasing other environmental impacts.