The Calcium Looping process for energy storage: Insights from in situ XRD analysis

This work reports a novel in situ XRD analysis on the multicycle calcination/carbonation of natural limestone and dolomite at relevant conditions for thermochemical energy storage (TCES) concentrated solar power (CSP) plants. The experiments allow analysing noninvasively time evolution different phases involved Calcium Looping (CaL) process. Our has revealed new key features to understand progressive loss multicyclic carbonation reactivity CaO derived from calcination. CaCO3 structure formed first step decomposition smaller unit cell volume than naturally present limestone. that stems shows greater compared size nascent crystals their relatively higher is related presence inert MgO crystals, which prevent sintering crystallite growth. However, increases monotonically with time, progressively hampers hindrance effect. also positive correlation between growth decline preferred orientation (1 0 0) plane as number cycles increased loses reactivity. observed can be attributed incompletion carbonation. unreacted remains calcination suffers severe hinders its Thus, fraction fresh, reactive nucleates old less declines cycles.