(264b) Continuum Model for Transport Phenomena and Thermochemical Reactions in Oxidation Reactors for High-Temperature (>1000 °C) Heat Extraction

A transient three-dimensional heat and mass transfer continuum model was developed to simulate the transport phenomena coupled with exothermic oxidation of magnesium-manganese-oxide particles in a high-temperature moving-bed reactor for thermochemical energy storage. The reactor included direct high-temperature heat extraction at temperatures greater than 1000 °C. The model was applied to simulate a corresponding experimental setup, the results of which are used for detailed model validation. The predicted temperature and oxygen concentration profiles were in good agreement with experimental data. A follow-up power budget and efficiency comparison between the model and experiments demonstrated excellent agreement, with a predicted steady-state efficiency of 29.4% for a baseline set of operating parameters. The performance of the reactor was further investigated through two parametric studies (varied particle flow rate and gas extraction ratios), which demonstrated a strong dependence of reactor efficiency (varied between 15% – 40%) on both operating parameters. The present heat and mass transfer model will be extremely useful in further reactor design and scale-up studies, as well as for selection of operating conditions to maximize efficiency.