Guðmundur Gunnarsson is a Senior Scientist/Project Manager at Tæknisetur (IceTec), Iceland.
Title of presentation: CO2 free aluminium for energy storage
Aluminium has a volumetric energy density of 23.4 kWh/l, which is higher than that of liquid hydrocarbon fuels and much higher than that of gaseous fuels like methane and hydrogen, that are stored at high pressures. Aluminium could therefore be an interesting option for seasonal storage of energy. Production of aluminium is an energy intensive process which in Europe requires an electric energy input of 15.1 kWh for production of 1 kg of aluminium from alumina. In addition, the energy input from the carbon anodes used in the process is about 3.8 kWh/kg aluminium. The energy required is therefore about 19 kWh/kg aluminium, which can be compared to the specific energy density of aluminium which is 8.63 kWh/kg. For aluminium to become energy storage alternative with low carbon footprint, energy consumption in production of aluminium should be decreased and CO2 from the process eliminated. Preferably electric energy for aluminium production should also be of low carbon footprint. In this presentation work in Iceland on development of a CO2 free aluminium process will be described. This work in based on the use of metallic anodes instead of carbon anodes and use of titanium diboride cathodes instead of carbon cathodes. Approaches to recover energy from aluminium will also be briefly described with special emphasis on projects where IceTec is a partner.
