Background Glass is a key element to many industries. In 2006, the world market for flat glass was estimated at 42 million tonnes, which is equivalent to 4.2 billion m3 of glass with a thickness of 4 mm. In Western Europe, the average yearly consumption is 18 kg per person. Unfortunately, the production of glass requires high levels of energy and entails the emission of pollutants (SOx and NOx). Acid rain comes from the reaction of water with these air pollutants: SOx and NOx. The European Commission has set targets to be reached by 2020 in order to limit the negative impact of pollutants (COM (2005) 446 final). Compared to figures for 2000, and in order to achieve this objective, S02 and NOx emissions will have to decrease by 82% and 60% respectively, by 2020. Given the high level of energy consumption, the EU is aiming to reduce greenhouses gases emissions (GHG) by 8% in 2012 compared to 1990 levels. In addition, the EU has already taken a firm independent commitment to achieve at least a 20% reduction of GHG emissions by 2020. In order to tackle the issue of climate change, the EU must make economical and societal changes. Objectives The HotOxyGlass project aimed to demonstrate that the environmental impact of the flat glass production industrial process can be reduced. The target was to decrease energy consumption by 25% and emissions of carbon dioxide (C02) by 15%, nitrous oxides (NOx) by 83% and sulphur oxides (SOx) 34.5%. Such reductions can be achieved using pure oxygen instead of air as an oxidiser in the combustion process and pre-heating reactants (fuel and oxidiser) to very high temperatures. Beyond demonstrating the technical feasibility in production conditions, the project planned to assess the environmental impact of this environmentally friendly industrial process. Furthermore, the environmental benefits of the project would be widely disseminated. Results The HotOxyGlass project demonstrated a furnace that combines the oxy-combustion technique (use of oxygen of 92-100% purity instead of air) with the pre-heating of reactants (oxygen and natural gas) involved in the combustion. Oxy-combustion avoids ‘unnecessary’ production of nitrogen that lowers combustion rates: associated oxy-burners generate higher temperatures than those produced by air combustion (2 600°C compared with 1 900°C), giving rise to greater productivity. Moreover, heat generated during the glass production process is reused to preheat the oxidiser and the fuel. In the HotOxyGlass furnace, flue gases at a temperature of 1 450°C are directed towards a recuperating devise when they leave the furnace combustion chamber. In this device, atmospheric air is introduced, and there is a heat exchange with flue gases. At the exit of the recuperating devise, the atmospheric air is heated to 750°C. Atmospheric air is merely used as a medium to convey heat. The hot air is then directed towards heat exchangers designed to preheat reactants: oxygen is preheated at 550°C, natural gas at 450°C. The project achieved its expected results: the hot oxy-combustion prototype furnace demonstrated lower energy consumption and lower pollutants emission compared to a state-of-the-art furnace. Due to the heat recovery process, the furnace was also shown to be more efficient as fewer reactants are necessary for the combustion. Regarding specific environmental results, the average values obtained with the furnace operating in stabilised combustion settings are the following: Energy consumption reduced by 25% (with a margin of 2%) CO2 emissions reduced by 15% (margin of 3%) NOx emissions reduced by 83% (margin of 5%) SOx emissions reduced by 38%.According to the beneficiary, the LIFE+ funding provided a strong incentive to optimise as much as possible the furnace's settings in order to reach the ambitious objectives. While the use of oxygen and natural gas technology has been demonstrated for flat glass furnaces, it can be implemented in any factory generating fumes to reduce the overall environmental footprint. The steel, iron, cement and boiler sectors are good candidates for future implementation. From an economical point of view, in the long term despite higher construction costs, savings on energy costs can be expected thanks to the HotOxy technology, especially in the context of the constant increase in energy prices. The technology will, also, trigger off new business opportunities for suppliers of the industry, that have the need of specific installations for the heat recuperation infrastructure and the use of oxygen as oxidizer. Thanks to this good experience and success in managing technical challenges encountered, the beneficiary will pursue innovation to reduce the environmental impact of flat glass production. The technical solution is both environmental and cost effective in the medium run, so a wider implementation of similar furnaces can easily be expected by the end of 2020, at first within the AGC group, then at the competitors plants. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan/After-LIFE Conservation Plan (see "Read more" section).