(498g) Thermodynamic Analysis of CaCO3/CaO Looping for High Temperature Thermochemical Energy Storage

High temperature power cycles, such as the supercritical carbon dioxide (CO₂) cycle, are promising technologies currently being investigated by the international research community for concentrated solar thermal power generation (CSP). These power cycles have the potential to increase the overall efficiency of the power plant compared to state-of-the-art steam Rankine cycles and thereby reduce the levelized cost of electricity (LCOE) of CSP. Therefore, novel thermal energy storage materials and processes are required to successfully couple concentrated solar power collectors with high temperature power cycles.

In this context, the CaCO₃/CaO thermochemical cycle is an attractive process for thermal energy storage that can provide dispatchable concentrated solar thermal energy at temperatures between 650â??980°C, appropriate to use with high temperature power cycles. Current research efforts focus on material development and solar reactors. However, there is a need for investigation into the field of system integration to support and verify the viability of this concept.

In this work, we evaluate the performance of a CaCO₃/CaO system coupled to a supercritical CO₂ power cycle for continuous electricity production. This investigation has identified high-energy demanding subsystems that require minimization to improve the overall efficiency of the process. The effect of the operational conditions (temperature and pressure) in the calcination receiver and carbonation reactor on overall efficiency are also investigated.