Fluidized bed reactors for solid-gas thermochemical energy storage concepts - Modelling and process limitations

Thermal energy storage (TES) systems show high potential to reduce the dependency on fossil fuels and to accomplish the shift towards sustainable energy systems. Thermochemical energy storage (TCES) provides significant advantages compared to other TES systems, including nearly loss-free storage at ambient pressure and temperature, high energy density and site independence. This paper provides a method to model fluidized bed reactors (FBR) for solid-gas TCES concepts based on solid-state kinetics and fluidization hydrodynamics using the reaction couple MgO−Mg(OH)2 for demonstration. Also a process to integrate such systems into industrial applications is proposed. Furthermore the supply of steam during the heat release process, which constitutes a major drawback of the system, is quantified in order to assess the limitations of such a process.