Comparison of kinetics and thermochemical energy storage capacities of strontium oxide, calcium oxide, and magnesium oxide during carbonation reaction

Abstract

In this work kinetics of carbonation reaction of strontium oxide was investigated using the well-known random pore model. This non-catalytic gas-solid reaction can be utilized both for carbon capture and storage (CCS) and thermochemical energy storage (TCES) applications. In order to obtain kinetic parameters and reaction rate equation, a set of experiments ranging from 800 °C to 950 °C in temperature and 5 to 40 vol% in concentration of CO2 were conducted. It was concluded that fractional function describes the concentration dependency of reaction rate very well. The activation energy of this reaction was calculated to be about 64 kJ/mol and the best exponential function indicating temperature dependency of CO2 diffusivity through the product layer was also estimated. Furthermore, it was attempted to depict the importance of this reaction for CCS and TCES purposes. This goal was achieved by comparing our results with those of around 50 similar researches carried on MgO, CaO, and SrO-based sorbents. Comparison was done using six screening criteria; i.e. CO2 uptake, CO2 uptake rate, conversion, conversion rate, thermal energy, and thermal power.