Abstract: The present invention relates to a method for treating CO2 by electrochemical hydrogenation, said method comprising: a step of transferring heat from a heating means (160) towards a proton-conductive electrolyser (110) such that said electrolyser (110) reaches an operating temperature suitable for electrolysing steam; a step of feeding the CO2 produced by said heating means (160) at the cathode of the electrolyser; a step of feeding the steam at the anode; a step of oxidising the steam at the anode; a step of generating protonated species in the membrane with proton conduction; a step of migrating said protonated species into said proton-conductive membrane; a step of reducing said protonated species on the surface of the cathode into reactive hydrogen atoms; and a step of hydrogenating the CO2 on the surface of the cathode of the electrolyser (110) by means of said reactive hydrogen atoms, said hydrogenation step enabling the formation of CxHyOz compounds, where x?1; 0<y?(2x+2) and 0?z?2x.

Abstract: The present invention relates to a process for preparing mineral particles (p) from mineral species precursors, said process comprising a step (E) in which a fluid medium (F) containing said precursors in solution and/or dispersed in a solvent is injected into a reactor containing CO2 in the supercritical state by way of an injection nozzle opening into a zone where the supercritical CO2 is at a temperature greater than or equal to the temperature for conversion of the precursors into corresponding mineral species. The invention also relates to the particles (p) as obtained by the process, as well as uses thereof.