Incineration in the Spotlight: Revised WI BREF

The Ardley Waste to Energy plant under construction in Oxfordshire, UK implements the Best Available Technique which will be described in the future BREF Photo by APS (UK) Ltd and courtesy of Clugston-Viridor and CNIM For many years European industrial emissions policy has taken an integrated approach, with the use of Best Available Techniques at its heart. While not originally mandatory, by 2010 the reference document outlining best practice for waste incineration became legally binding. Now however, those reference documents are to be revised, along with the emission limits they set. By Hubert de Chefdebien and Guillaume Perron-Piché Europe leads the world in environment protection policies, in particular thanks to the Best Available Techniques (BATs) and BAT Reference Document (BREFs) which seek to minimise industrial activities' environmental impacts through the use of proven techniques and technologies. With the new approach under the Industrial Emissions Directive (IED), where BREFs become legally-binding, the way they are written needs to be changed. As the revision of the Waste Incineration (WI) BREF is about to commence, it is important to note that the European Waste Incineration industry already achieves very good emission results. Since the mid-1990s, the cornerstone of the European industrial emissions policy has been an integrated approach. Simply put, it is not wise to protect an environmental media, such as air, by shifting the burden on – for example through greater energy or water use. The integrated approach was outlined in 12 criteria listed in the Integrated Pollution Prevention and Control (IPPC) Directive from 1996. These criteria include for instance the emissions to air and water, the consumption of raw materials, the energy efficiency, the need to prevent risks or accidents and the use of low-waste technology. The IPPC Directive became the leading Europe-wide legislation assessing industrial activities' impacts while also balancing each industry's specific realities and costs related to environmental protection. The IPPC Directive brought this integrated approach to the permitting process, whereby all EU industrial installations were henceforth required to have an environmental permit to operate and to implement BAT to reduce their environmental impact. The Directive stopped short of mandating uniform limits for all industries at the European level. Some sectors, such as the waste incineration industry, though, were already covered at a European level and many Member States of the then EU15 had stringent requirements on other industries. What these Best Available Techniques for various industries are was to be laid down at a later stage in BAT Reference Documents, the well-known BREFs. The EU as Forum to Determine BATs by Activity The IPPC Directive created an Information Exchange Forum, managed by the European Commission's Joint Research Centre's Seville location, called the European IPPC Bureau (EIPPCB). The Forum, convened by the Commission and comprising industries, Member States and NGOs, also created industry-specific Technical Working Groups. These were set-up to exchange and identify BATs based on input from the involved parties, and agree on what could be done, for example, to minimise air emissions. From this exchange, 33 BREF documents were written covering all the industries in the scope of the IPPC Directive. These massive technological textbooks, each hundreds of pages long (precisely 638 pages for the Waste Incineration BREF published in 2006), include a list of Best Available Techniques, some of them with related BAT Associated Emission Levels (BATAELs), which indicate the average emission levels reachable under normal operation. The existing BREFs, which are available freely online, were to give operators and competent authorities information on what can be considered BAT for the sector and what levels of emissions can be reached when implementing them. However applying the BATs from these BREFs was not mandatory and there was no direct link between the levels of these IPPC-BATAELs and the Limits set up as Emission Limit Values (ELVs) in the permits. A strengthened approach Between 2007 and 2010, the EU institutions recast the IPPC Directive, keeping the Integrated Approach and merging it with six other Directives, including the Waste Incineration Directive, the Large Combustion Plants Directive, covering the thermal power plants sector; and four other sectoral directives) under the IED. And this new proposal had teeth: the implementation of techniques achieving the performances of Best Available Techniques described in the part of the BREF called BAT conclusions became legally-binding. Moreover, the ELVs laid down in the former directives for incineration and a few other industries were copied in the IED. The difference is that they became considered as maximum ELVs, a kind of "safety net": the new general rule is that the ELVs to be set up in the operating permit by the competent authority must not be higher than the sector's BATAELs. There is therefore a major change in the BATAELs' essence since, instead of a typical level as it was under the IPPC, it will be from now on a ceiling value for Emission Limit Values in the permit. This is actually recognised by Article 13.7 of the IED, implying that the existing (IPPC) BATAELs are not to be used to set ELVs with the legally-binding nature of the new Directive. And, therefore, new IED-compatible BATAELs must be elaborated. Figure 2: In chronological order all the ½-hr average values of HCl measured over a year after treatment in a typical and efficient Flue Gas Cleaning system of the Dry type installed on a Municipal Solid Waste incinerator line. When looking at this graph, the typical LEVEL of emissions to consider (i.e. BATAEL s according to the IPPC directive) for this line would be, let us say, between 1 and 6 mg/Nm3. However, the value from this line to consider in order to establish a CEILING VALUE NOT TO BE EXCEEDED by Emission LIMIT VALUES (i.e. BATAEL s according to the IPPC directive) will be around 50 mg/Nm3. (Graph by L. Kosior, SITA) Waste Incineration under the IED In 2010, when the IED was published, Waste Incineration had already been complying for years with very strict requirements, in stark contrast to other sectors that demanded and obtained transitional plans in the IED to continue emitting more than the ELVs. Indeed, Waste Incineration has been regulated by the WID (Waste Incineration Directive) since 2000, itself a follow-up of two Directives from 1989 on prevention of air pollution from municipal waste incineration plants. For example, despite the large fluctuations in pollutants load upstream of the Flue Gas Cleaning systems, Waste Incineration plants are controlled on a much larger number of substances than any other industry. For the few substances also regulated in other industries (such as SOX or Dust), Waste Incinerators have lower ELVs and with much less possibility to derogate or exceed ELVs. Finally, ELVs for incineration plants are mandatory, not only in Normal Operating Conditions (NOCs) like for other industries, but also during Effective Operating Time (EOT) which also includes some Other Than Normal Operating Conditions (OTNOCs). The generalised compliance with these very stringent requirements was the result of a combination of a dynamic industry supplying flue gas cleaning equipment guaranteeing compliance with ELVs, and of the widespread use of such flue gas cleaning equipment at Waste Incineration plants. Figure 1: Under the IPPC Directive, BATAELs were typical average values obtained in operation when implementing the Best Available Techniques. The new IED-compatible BATAELs, which aim at capping the ELVs set up in the permits, must be elaborated differently Evolution of Waste Incinerati on since 2006 When examining government-issued emission reports compiling all emission sources, it is clear that Waste Incineration is not a problem for air quality. This was even recognised by leading decision-makers, including for example, Jürgen Trittin from the Green Party , who was Minister for the Environment in Germany. These declarations were also supported by scientific studies, all recognising that the current emissions from Waste incinerators in the EU are so low that they are not a key issue for Environment and Health. On the other hand, unlike many other sectors that still have room for reducing their emissions – and for which the IED was designed – there is nearly no margin to lower limits for incinerators because the levels currently obtained result from the use of Best Available Techniques for decades. In short, since operation already is at the optimum trade-off between releases and consumptions, further lowering air emissions at the stack would increase environmental impacts elsewhere. For instance, in some cases it is possible to slightly reduce the emission of a certain pollutant by overdosing a reagent. But at the emission level already reached by incineration, a slight improvement for air will require consuming far more resources (see Figure 3), thus generating more waste. This is because each extra quantity to capture beyond the optimum is exponentially more difficult and costly to abate than the first ones in a raw gas. Would it not have been better to use this extra reagent on other sectors where such pollutants are poorly or not abated? Figure 3: (Same data as in figure 2 but arranged by value) On this example, lowering the ½-hr HCl ELV from 60 to 10 mg/Nm3 would reduce the already very low HCl emitted flow by 0.9% but would require over 1000 times more reagent in mass (Original graph by L. Kosior, SITA) Plants are approaching the limit of the emission abatement capabilities and of the measurement systems, which cannot reliably detect lower concentration levels than those emitted by incineration plants. Still, technology suppliers kept on seeking improvements in Waste Incineration's environmental impact. Plants built today reach low long-term emission levels more efficiently in terms of reagents and energy: less residues are produced and operation is cheaper. But the heterogeneous nature of waste still implies that some emission peaks will occur, justifying, inter alia, the need to keep a margin between typical operation and Emission Limit Values. What are the challenges for the WI BREF revision? The IED recognises the need to reset the BREFs, the BAT Conclusions and the BATAELs to adapt to the new approach of the IED. The BREFs upon which the legally-binding ELVs will now be based must all be revised, and this is imminent for the waste incineration sector. Since the technology already yields excellent emissions abatement results and the incineration sector contributes very little to overall pollutant emissions, the challenge remaining is to quantify this and in particular to take into account that emissions from waste incineration inevitably fluctuate due to the inhomogeneous nature of this very peculiar fuel. Compared to many other waste treatment activities for which hardly any monitoring was done on their pollutant releases and transfers, there are huge datasets of operational values from incineration plants which must now be translated into legally-binding BATAELs. This is a statistical exercise that is particularly challenging because of the very low level of current emissions of incineration. This industry is the only one which must comply with ELVs even in some Other Than Normal Operating Conditions, and which must cope with a fuel that is ever-changing due to its intrinsic nature. If an emission peak is caused by the waste input, should a high emission value be discarded as non-BAT? Or should it instead be included in the averages to reflect the changing nature of waste, and not be discarded as alleged result of a failure of air protection equipment? Bourne Construction Engineering worked on the 2000+ tonnes of structural steel, with the scope of works including delivering the super structure to support the structural steel for both the envelope and bunker cranes, waste bunker, office blocks Credit: Bourne More to Come For more on this important topic don't miss the follow up feature in the July/August issue which will look into the ways to derive BATAELs from operating values. This procedure aims at characterising the excellent results already obtained in European plants and integrating these values into workable and legally-binding BATAELs. Hubert de Chefdebien is chairman of ESWET's Technical Committee and is a member of various waste management organisations He represents the Waste to Energy sector in numerous forums, including at the European Commission's BREFs Technical Working Groups. Guillaume Perron-Piché is policy officer at ESWET Glossary BAT: Best Available Technique BATAEL: Best Available Techniques Associated Emission Level BREF: BAT Reference Document EIPPCB: European IPPC Bureau (Seville) ELV: Emission Limit Value EOT: Effective Operating Time IED: Industrial Emissions Directive (2010/75/EU) IPPC: Integrated Pollution Prevention and Control Directive (96/61/EC) NGO: Non-Governmental Organisation NOC: Normal Operating Conditions OTNOC: Other Than Normal Operating Conditions WI BREF: Waste Incineration BREF WID: Waste Incineration Directive (2000/76/EC)