A thermochemical energy storage materials review based on solid-gas reactions for supercritical CO2 solar tower power plant with a Brayton cycle

This work emphasizes the importance of thermal energy storage and the ways to do it: by sensible, latent, and thermochemical heat. The latter is the one that presents a better performance that allows mitigating the intermittency and the day-night alternation of the solar resource. The most important aspects to be considered for selecting thermochemical materials to be used in solar power generation systems are presented. The factors influencing the experimental analysis and the importance of the various research groups reporting these operating conditions are also presented. Not all authors report it for not giving it the importance it deserves. It is necessary to join forces to search for new materials that can be commercial in the medium term. This article reports a parametric review of the thermochemical systems proposed in the literature. Emphasis is placed on the importance of the inert gas used as a drag medium and its influence on chemical kinetics. The study case of CaCO3 is presented. Additionally, the thermodynamic analysis of the different materials is carried out to elucidate the storage capacity as a function of the inversion temperature (equilibrium temperature) and to define the set of possible reactions for each solar technology, particularly the central tower technology. The criteria for a good selection of materials suitable for storage are summarized. Emphasis is placed on carbonates and oxides as potential materials to meet the desired objective. In the reactions studied, the carrier gas has been shown to have a discernible influence on the activation energy. Hence, it is essential to carefully evaluate the different parameters involved in a solar power plant with thermochemical storage. It also shows a review of the progress made in the efficiencies of new-generation solar thermal plants and the success of supercritical CO2 gas turbine prototypes and the blends with other gases to perform the characteristics of the HTF.

Automated summary

This work emphasizes the importance of thermal energy storage and the different ways to achieve it. The use of thermochemical heat is highlighted as it offers better performance in mitigating the intermittency and day-night alternation of solar resources. The study focuses on selecting suitable thermochemical materials for solar power generation systems and discusses the factors influencing experimental analysis. The article also emphasizes the need for collaboration in searching for commercializable materials in the medium term. Furthermore, it provides a parametric review of thermochemical systems and highlights the importance of inert gases and their influence on chemical kinetics. The study also presents a thermodynamic analysis of different materials and provides criteria for selecting suitable materials for thermal energy storage.