EMISSIONS IN THE REFINING SECTOR

With the issuance of the first AIA (Integrated Environmental Authorizations) provisions starting in 2011, compared to the previous authorizations, there was a significant reduction in atmospheric emissions of all considered macro-pollutants (a 53% reduction for SOx, 29% for NOx, 38% for CO, and 48% for Particulates). The alignment of the AIA with the “BAT Conclusions” from 2014 led to further reductions in emissions of all macro-pollutants compared to the post-AIA situation (a 38% reduction for SOx, 27% for NOx, 33% for CO, and 46% for Particulates) (Table 1). Overall, atmospheric emissions of SOx, NOx, CO, and Particulates from refineries subject to state AIA have significantly decreased over recent years, showing a reduction between the post-review situation and the pre-AIA situation (71% reduction for SOx, 49% for NOx, 59% for CO, and 72% for Particulates) (Figure 2), thanks to the application of BAT and the implementation of stricter limits in AIA provisions in accordance with BAT AEL (Associated Emission Limits). Furthermore, for 2023, the actual emissions, i.e., those measured by the operators, of the aforementioned macro-pollutants were significantly lower than the authorized values, showing a substantial reduction compared to the post-review situation (52% for SOx, 45% for NOx, 85% for CO, and 86% for Particulates), even more pronounced when compared to the pre-AIA values (86% for SOx, 72% for NOx, 94% for CO, and 96% for Particulates) (Figure 1).

Regarding water discharges, the changes between 2011 and 2023 for the emissions of COD and SST flows (Table 2 and Figure 3) show reductions in the masses of pollutants discharged, by 26.9% and 85.5%, respectively. A comparison of the flows of Phenols and Total Hydrocarbons emitted between 2018 and 2023 (Figure 4) highlights a reduction in Total Hydrocarbon emissions by 26.8% and an increase in Phenols by 9.7%, a parameter that, however, shows a decrease compared to the previous year.

To complement the data on the comparison between emission performances of 2011 and 2023, Figure 5 shows normalized emissions of COD and SST, i.e., related to crude oil processed for the entire observation period. For both pollutants, a reduction in the quantities emitted from 2017 onwards can be observed, due to the short and medium-term effects of the implementation of the comprehensive AIA review decrees during 2017-2018. The new AIA provisions, compared to the pre-existing VLE (Emission Limit Values) concentrations in the initial AIAs, incorporate new BAT-AELs (Best Available Techniques - Associated Emission Limits) imposed by the “BAT Conclusions,” which are more restrictive and expressed in terms of the annual average concentration. These provisions required further technical improvements in pollution control and management systems, including upgrading and/or extraordinary maintenance interventions at wastewater treatment plants in some refineries, thus allowing a reduction in the amounts of COD and SST discharged into water.

In analyzing Figure 6, it shows a steady trend for Phenols, with a slight increase in 2022 followed by a decrease in 2023. For Total Hydrocarbons, an increase is noted in 2023 compared to previous years, except in 2018 when it decreased by approximately 27%. In relation to these data, it should be considered that the quantities of Phenols and Total Hydrocarbons are always two orders of magnitude lower than those of COD and SST, so the differences in Phenols and Total Hydrocarbons over the years are minimal compared to those of the other two parameters. Again, it can be stated that the slight reduction is due to the short and medium-term effects of the implementation of the 2018 AIA review decrees, for which compliance is required within 6 months of the issuance of the AIA Decree.

The percentage of waste recovered compared to the total produced, between 2011 and 2023, increased from 26.7% in 2011 to 42.7% in 2023. The lowest value was recorded in 2013 with 20% (Table 3 and Figure 7). The production of total waste per ton of crude oil processed has slightly increased from 4.2 kg/t in 2011 to 4.3 kg/t in 2023. Similarly, the production of hazardous waste per ton of crude oil processed increased from 2.7 kg/t to 2.9 kg/t; however, the production of non-hazardous waste per ton of crude oil processed decreased from 1.5 kg/t to 1.4 kg/t (Table 3 and Figure 8). The positive trend of the waste recovery index, as part of a waste management policy outlined in the “BAT Conclusions,” has led to a reduction in landfill disposal and a potential reduction in the consumption of raw materials.