An Integrated Reactor and Heat Exchanger Based on Porous Ceramic Materials for Thermochemical Storage of Solar Heat

Kurzfassung

During the last years the demand of energy is continuously increased. Thereby the usage of fossil fuels and the resulting emissions of CO2 become more problematic for the world climate. Renewable Energy Sources (RES) could give a way out of this situation and have become more and more interesting during the past years. One of the issues with renewable energy sources is to produce the energy in-line with the demand. Solar power plants with a storage medium are one technology that can overcome this problem. Air-operated Solar Thermal Power Plants in particular currently store thermal energy as sensible heat in porous ceramics. DLR is investigating approaches to augment the volumetric energy storage density of such porous ceramics by combining them with redox oxide pair systems that can operate as thermochemical storage materials employing solar heat during daytime to induce endothermic reactions and the reverse exothermic reactions to retrieve this heat during off-sun operation. Cobalt oxide and manganese oxide are among the most interesting materials for such thermochemical storage. Hybrid sensible/thermochemical storage systems were created by coating cordierite ceramics with oxide powders. Such systems were further tested in bench-scale in a specifically built reactor test rig with respect to their heat storage properties and showed good results. Solar Thermal Power Plants with coated storage Systems could be able to create electricity with solar heat the whole day long and thereby reduce the emission of CO2 significant.