After water, concrete is the most widely used material for the construction of housing and infrastructure. The world market for cement - the main material used for making concrete - is in excess of 2 billion tonnes/yr. However, cement production accounts for a significant proportion of manmade greenhouse gases (GHG), estimated to be approx. 5% of global CO2 emissions. Furthermore, the demand from construction industries is constantly increasing, especially in the developing world. Portland is the most common form of cement. It is made by the thermal treatment - calcination - of ground calcium carbonate (limestone) and clay to form a nodular material called ‘clinker’, which is then ground to produce cement. Production of Portland cement clinker generates average emissions of around 0.8 tonnes of CO2 per tonne, mostly from the chemical reaction of the raw materials, and to a lower extent from the combustion of fossil fuels. The cement industry has already taken major measures to reduce process-related CO2 emissions. These have focused on energy optimisation, clinker substitution in cements and fossil fuel replacement. However, these conventional approaches need to be complemented with other solutions, to contribute achieving the ambitious target set by Lafarge to reduce net CO2 emissions (per ton of cement) in 2020 by 33% compared to 1990.
The objective of the AETHER project was to demonstrate the feasibility of producing a new cement at industrial scale with significantly lower CO2 emissions compared with conventional Portland cement, within existing industrial installations, using a new and patented type of clinker shown to be successful in lab trials. The project aimed to validate the environmental, technical and economic properties of the cement produced, which in the longer-term may contribute to a cement-producing process that achieves the EU’s CO2 reduction targets.
The AETHER project produced a new type of cement at the industrial scale with significantly lower CO2 emissions and a lower energy consumption compared with conventional Portland cement, within existing industrial installations. Two clinker trials were carried at two different industrial sites operated by coordinating beneficiary Lafarge in France, in 2011 and 2012. These trials confirmed that AETHER clinker could be produced in a Portland plant with a dry/semi dry process, and demonstrated the feasibility of industrial-scale production using traditional raw materials.
Associated beneficiary BRE (Building Research Establishment), based in the UK, assessed the trial results, after a total of 5 000 tonnes of the new clinker was produced. The AETHER concrete was reported as performing well, and recommendations were provided for the standardisation of AETHER products. Around 40 tonnes of raw materials from Lafarge’s plants or suppliers were treated to produce AETHER clinker and cement products, with a broad range of compositions (13 different mixes) being clinkered under different production conditions. Clinkers were also prepared and tested in the facilities of associated beneficiary the Institute of Ceramics and Building Materials (ICiMB) in Poland. Altogether, twenty different types of AETHER cements were produced during the project. The project team formulated an optimal chemical composition of raw mix for AETHER clinker, and produced technological guidance for its industrial-scale production. Final assessment results showed the feasibility of producing the new cement with a 25-30% reduction in CO2 emissions compared with conventional Portland cement production; a figure independently confirmed by Lafarge and BRE. Depending on the process, the new cement was also produced with a minimum 15% reduction in energy consumption. This is because the new process improves energy efficiency, because the raw materials need less heat for their transformation. Therefore, environmental benefits derive both from reduced greenhouse gas emissions as a result of the process, and less energy consumed during the process.
The project’s dissemination activities were aimed at the general public and specific target groups, such as scientists and specialist industrial media, at national and international level. The project produced technical reports, scientific publications and a website. Awareness was increased among the different stakeholders, especially potential customers, scientists, and other cement companies. According to the beneficiary, competitors have already started working in the same direction as the AETHER results. The project contributes to the implementation of a range of European legislation. The development of the low CO2-emitting clinker, and the more energy-efficient transformation process, can help the cement industry reduce emissions in line with the Communication on EU policies and measures to reduce greenhouse gas emissions (COM(2000)88). The project contributes to the objectives of the Directive establishing a scheme for greenhouse gas emission allowance trading (2003/87/EC): the goal of Lafarge is to achieve a reduction of 33% of CO2 emissions in 2020 compared to the reference 1990, using traditional levers together with the innovative class of cement proposed as one of the solutions to achieve this goal. The project also helps implement European energy efficiency policy (e.g. COM(2007)1 and Green paper on energy efficiency or doing more with less COM(2005)265).
The main innovative aspect of the project was the complete demonstration of the AETHER clinker and cement production at the industrial scale, based on original raw materials and modifications in the production process. This directly reduced the CO2 emissions generated by cement production, by reducing the fuel needed to heat and transform the raw materials.
Work on developing applications for the new process is being continued in the AETHER II project, funded as part of the EU’s Sustainable Industry Low Carbon (SILC) scheme, an initiative that aims to help sectors achieve specific greenhouse gas emission reductions in order to maintain their competitiveness.
Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).