Design and performance verification of a fast-reaction thermogravimetric analyzer

•Ca(OH)2/CaO fluidized thermochemical heat storage kinetics equipment was developed.•The excellent heat and mass transfer provided by the new equipment was validated.•The innovation achieves kinetics that are closer to fluidization conditions. Ca(OH)2/CaO fluidized thermochemical heat storage can provide considerable heat storage power, and is a promising large-scale energy storage technology. Owing to the limitations of existing gas–solid reaction kinetics research equipment, there is a lack of Ca(OH)2/CaO reaction kinetics research under fluidization conditions, with a lack of reliable reference data for the design and operation of fluidized bed reactors. In response to the above-mentioned problem, and through our research, we developed a fast-reaction thermogravimetric analyzer to provide samples with excellent heat and mass transfer conditions close to fluidization. The fast-reaction thermogravimetric analyzer enables the reaction of Ca(OH)2 to mainly take place under isothermal conditions by rapidly moving the high-temperature reactor, as well as inputting purge gas at a high flow rate to provide excellent mass transfer conditions for the sample, while obtaining real-time and reliable mass data for thermal analysis kinetics studies. Through an in-depth performance verification, the apparent activation energy of char combustion in a TGA (144.82 kJ/mol), fast-reaction thermogravimetric analyzer (88.32 kJ/mol), and fluidized bed reactor (47.23 kJ/mol) were obtained by the model-free method (iso-conversional). The comparison of data proved that the fast-reaction thermogravimetric analyzer could obtain kinetic parameters similar to a fluidized bed reactor, which was also verified using other materials. Therefore, the fast-reaction thermogravimetric analyzer developed in this study can provide a new solution for studying the reaction kinetics of fluidized thermochemical heat storage for Ca(OH)2/CaO, in addition to acting as a reliable reference for the design and operation of fluidized bed reactors.