Room temperature hydrocarbon generation in olivine powders: Effect of mechanical processing under CO2 atmosphere

The present work focused on the weathering reaction of olivine under CO2 atmosphere to produce light hydrocarbons via mechanical process by using ball milling apparatus. The evolution of methane and light hydrocarbons with different amount of water is reported in detail, and the process efficiency compared with the thermally activated one. Methane and light hydrocarbons productions of at least three orders of magnitude larger, are detected for the mechanically activated process. Such significant improvement can be attributed to the extreme conditions experienced by the powders processed at each impact during ball milling, whit an estimated local temperature of 648 °C. Structural and microstructural characterization reveals the formation of serpentine and magnetite-based minerals, and the occurring of the carbonation process, which competes with serpentinization, confirming that carbon capture can take place during ball milling of olivine under low pressure of CO2.