PHOENICS · Photocatalytic and Energy – storage Innovative Concretes

Photocatalytic and Energy – storage Innovative Concretes

Within the European Union, buildings account for 40 % of total energy consumption and a third of CO2 emissions (Directive 2010/31/EU). In the effort of tackling climate change by reducing carbon footprints and saving resources, reduction of energy consumption in buildings is a paramount objective to target. Furthermore, it has been demonstrated that climate change highly depends on air pollution too (J. H. Seinfeld, Atmospheric chemistry and physics: from air pollution to climate change, 1 edn., Wiley, New York, 1998), hence the need to improve air quality in European Countries has been identified as a major requirement to be achieved within the next decade (Directive 2008/50/EC). Photocatalytic concretes, i.e. concretes with exposed surfaces modified with TiO2 photocatalysts, have shown ability to reduce air pollution mainly caused by nitrogen oxides (NOx), sulphur oxides (SOx) and volatile organic compounds (VOCs) as well as providing self cleaning effect through the light induced super-hydrophilic nature of light irradiated TiO2 surfaces and ability to degrade compounds causing dirt and stains. In this project highly visible light active TiO2 photocatalysts are implemented into concrete in order to provide air depollution effect to the final material surface. Furthermore, novel encapsulated Phase Change Materials (PCM) will be introduced so as to optimise energy efficiency in buildings where the photocatalytic concrete will be used. The combination of such processes (photocatalysis and energy storage) will therefore offer a chance to produce innovative, multifunctional concretes with enhanced structural, depolluting, self cleaning and energy saving properties. Theoretical calculations and modelling allowed the identification of suitable doped and codoped TiO2 systems for achieving visible light sensitisation and offering at the same time materials that are stable and compatible with the typical chemical environment of cement. The results of PhoEnICs project allowed for the development of a longer and bigger research project called Light2CAT (www.light2cat.eu) where an European Consortium led by the Danish Technological Institute, benefitting of ca. 3.5 M€ as a EC contribution, will finalise the development of these materials and will carry out an industrial scale up. PhoEnICs project also developed a novel pumice stone / PEG600 composite phase change material (PCM) to be used for thermal energy storage in construction. The high stability of the PEG600 impregnated pumice stone in the cement environment makes this system highly attractive for the use in concrete for walling and flooring. The availability of a high latent heat of fusion/crystallisation that can be easily exchanged allows to maintain the temperature of indoor spaces where the PCM is used much more constant than in the case of walls/floors built using ordinary concrete. This translates into a great energy and money saving effect during both winter (heating of buildings) and summer (cooling of buildings). Furthermore, the composite PCM developed in PhoEnICs project offers great economic advantages in terms of manufacturing. This mainly derives from very low cost raw materials, being the pumice stone an inexpensive highly available commodity (market price around 45 EUR/m3) and the PEG600 (the actual PCM) on average half the price (130 – 140 EUR/Kg) than paraffins commonly used as room temperature PCMs, like high purity heptadecane C17H36.

Data: CORDIS, © European Union