Assessing the environmental performances of waste-to-energy plants: The case-study of the EMAS-registered waste incinerators in Italy

This study evaluated the environmental performances of 15 Italian waste incineration (WI) plants registered to EMAS. From the EMAS Environmental Statements, the validated data related to 5 environmental aspects (emissions to air, energy consumption/production, waste production and reagent consumption) and 24 key indicators were analyzed to describe and assess the environmental performances of the plants in 2017–2019 in relation to the best available techniques associated emission levels (BAT-AELs) and other sectorial reference values. All air pollutants’ average concentrations resulted significantly below the upper BAT-AELs, the majority under the lower BAT-AELs, with an overall slightly decreasing trend (-4.6%). The specific productions of bottom and other ashes were steady over time and just above the lower characteristic values. The specific energy consumption was higher than the average European performance and stable over time, while the specific reagent consumption was harder to evaluate, with results varying for the different reagents. An evaluation of the influence of the WI plants’ characteristics on the environmental performances was also performed considering 13 different parameters (e.g., flue gas cleaning technologies, waste treatment capacity, etc.). A correlation analysis highlighted the positive influence of the pre-dedusting stages on overall emissions, specific reagents consumption and specific waste production, and of the plant size on the specific energy production. This study demonstrated that EMAS can provide a tool to evaluate the environmental performances of WI plants and compare different installations using certified data. It also highlighted the excellent performances of the Italian WI plants registered to EMAS compared to the sectorial references.