Youssef Berro, Jean Puig, Marianne Balat-Pichelin

Abstract: Recent studies focused on the carbothermal reduction of magnesia as a possible production process of metallic Mg powders that can be used as transportation fuels due to their high energetic value, absence of greenhouse gas emissions, and the ability to regenerate them (through reduction/combustion cycles). Herein, we investigated the development of the reduction process, under vacuum, in the Sol@rmet reactor using concentrated solar energy and charcoal reducing agent as sustainable sources. We shown that the reduction is improved by controlling various parameters as the argon flow, the heating rate, the retention time, the type of the collector filter, and the binder used to form the C/MgO pellets. In fact, a circulating swirl flow inside the reactor allows to prevent the condensation of the produced Mg inside the reactor and to purge out the produced CO, thus reducing its partial pressure and accelerating the reaction. Moreover, using a metallic filter has improved the collection of produced Mg powders. Finally, we found that polyvinyl alcohol (PVA) and bentonite binders have a catalytic effect on the reaction with the best Mg yield of around 96%, with 96% Mg purity, reached when the temperature is raised progressively over 22 min and using 5% starch + 5% bentonite binders.

Keywords: metallic fuels, carbothermal reduction, magnesia, concentrated solar energy, high temperature.

Date Published: November 2, 2021
DOI: 10.11159/ijmmme.2021.003

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