Low NOx Burners: A Comprehensive Analysis of their Applicability, Availability and Sustainability to reduce NOx Emissions within the EU Regulatory Framework for the Ceramic Industry

This thesis follows a step-by-step approach to investigate the issue of atmospheric emissions in the ceramic sector, considering the ongoing revision of the Ceramic BREF under the new IED 2.0 Directive and the stricter proposed emission ranges values for pollutants released into air. The analysis originated from a request by Confindustria Ceramica and ACIMAC (Association of Italian Manufacturers of Machinery and Equipment for Ceramics) and was developed under the academic guidance of the University of Modena and Reggio Emilia. The publication of the first draft of the revised ceramic BREF, a document whose purpose is to identify the Best Available Techniques (BATs) for eliminating or, where not possible, reducing pollutant emissions, represents a pivotal moment for the sector. The Best Available Techniques identified are required to combine environmental benefits, with conditions of economic viability, investment feasibility, and enhanced process efficiency. Alongside BATs, the document will set new emission and environmental performance ranges, which will serve as reference points to the competent authorities for updating the Integrated Environmental Permits (IEP) of European ceramic companies in each country, with the final goal to harmonize the emission and environmental performances of the ceramic industry across the Union. In particularly the present study investigates nitrogen oxides (NOx) emission for the ceramic sector, formed during the combustion processes, the emission range and the potential application of the Best Available Techniques proposed by the Join Research Centre of the European Commission. Until recently, nitrogen oxides (NOx) were not considered a key pollutant in the ceramic industry. However, as a result of the combined influence of evolving European environmental legislation and regional requirements, the newly proposed emission limits may entail a reduction of up to 80–90% compared to the current emission limit in force in Italy. On top of this, among the Best Available Techniques (BAT) proposed for the abatement of NOx emissions, the sole technological solution, distinct from process optimization or operational measures, is the deployment of Low-NOx industrial burners. Despite being recognized as the most effective options at industrial level for other sectors, these burners are currently not implemented in the ceramic industry. This observation raises the central research question of this thesis: Why has a technology indicated as BAT for other sectors and proposed for the ceramic industry not yet been adopted in Europe's most prominent ceramic manufacturing district? To address this question, the research path adopted in this thesis involved several stages: • An overview of the ceramic sector and its production subprocesses; • A detailed analysis of the European and national regulatory framework, including the presentation of the first draft of the revised Ceramic BREF; • An in-depth examination of NOx formation mechanisms, their sources within the ceramic process, and current mitigation techniques; • An evaluation of the potential implications of the new BREF on the Italian ceramic industry, focusing in particular on the introduction of Low-NOx burners as a required emission reduction measure. The core section of this thesis presents a comprehensive technical review of Low-NOx burner technologies, examining their operating principles, application sectors, and typical working conditions. Through collaboration with leading Italian ceramic manufacturers and technology providers, the study investigates the compatibility of these technologies with the operational parameters of the ceramic subprocesses that generate the highest NOx emissions. The objective is to assess whether the implementation of such technologies can realistically achieve, under standard operating conditions, the emission performance levels outlined and required in the draft version of the Ceramic BREF.