Development of a moving bed pilot plant for thermochemical energy storage with CaO/Ca(OH)2

Thermochemical energy storage, for instance with Ca(OH)2, offers high energy densities at low material costs and could therefore be a promising storage alternative for CSP-plants. Yet, due to the low thermal conductivity of the Ca(OH)2 material large storage capacities operated in an indirectly heated fixed bed also require large heat exchangers. In other words the fixed bed concept somehow opposes one of the main advantages of Ca(OH)2, its low material costs. One approach to overcome this issue is to detach the costly reactor with the heat exchanger (power) from the storage material (capacity). This can be accomplished by a moving bed concept where the material moves through the reactor. Therefore a novel moving bed pilot plant was developed within the consortium of the European project TCS Power. The pilot plant was set into operation and revealed important information about the material flow through the reactor and the operation strategy of a moving bed concept.