Improving the solar carbothermal reduction of magnesia for metallic fuels production through reactor designing, milling and binders

[摘要] The production of magnesium particles through the carbothermal reduction of magnesia using concentrated solar energy has engaged the attention of researchers as a sustainable production process. This process allows the effective employ of those particles as recyclable combustion metal fuels for terrestrial transportation having high energetic value with zero greenhouse gas emissions. Herein, we investigated the improvement of this production process, at low pressures, by designing the Sol@rmet reactor and using various catalysts. Simulations and experiments are performed to determine the parameters (inlets and flow rates) allowing a gas circulation in the reactor favoring the production of metallic magnesium powders. Modeling results were confirmed by experiments showing that a double argon entry creates a favorable swirl circulation, thus increasing the Mg yield from 52 to 68%. A further improvement, to reach around 85%, is attained by the mechanical milling the C/MgO powders. Additionally, we inspected the effect of binders and metallic catalysts (iron and nickel) on the reaction conversion and kinetics. Solar experiments proved that bentonite binder has a catalytic-like behavior allowing to reach values up to 95% of Mg yield and purity.

[发布日期] 2021-09-15

[关键词] Carbothermal reduction;Solar fuels;Catalyst;Reactor design;Bentonite binder