(22a) Reversible Carbonate & CO2 Reaction System for High-Temperature Thermo-Chemical Energy Storage

This presentation will discuss thermochemical energy storage at 300 – 750^oC based on reversible chemical reactions between CO₂ and alkaline metal oxides. These materials are inexpensive and abundant. During energy storage, the carbonate is heated up and decomposed into metal oxides and CO₂. The resulting metal oxide is stored at high temperatures, while the CO₂ gas is stored in an adsorbent vessel at ambient temperature. During energy release, the stored CO₂ reacts with the metal oxide to form the carbonate. The heat of chemical reaction involved in the process is several times higher than the typical latent heat provided by conventional phase change materials. High CO2 sorption capacity and rapid sorption/decomposition kinetics are critical to development of a compact storage system. A phase-transfer catalyzed sorbent system and monolith bed will be discussed in this presentation to dramatically enhance intrinsic reaction kinetics and mass transfer while maintain stable working capacity.