Combustion of Magnesium Particles in CO₂/CO Mixtures

Abstract

Magnesium is known to be a perspective fuel for engines which could use CO₂ from the atmospheres of Mars and Venus as an oxidizer. Combustion of magnesium samples introduced into a high temperature CO₂/CO mixture is experimentally studied. Measurements of the burning time as well as visual observations and spectral analysis of the flame show that the sharp transition from vapor-phase to heterogeneous combustion occurs with increasing CO content in the atmosphere. Study of the condensed products and thermodynamic analysis of magnesium particle combustion in CO, and CO indicate that the gas-phase reaction Mg + CO₂ = MgO + CO and the heterogeneous reaction Mg + CO = MgO + C occur during combustion in C02 whereas during combustion in CO the heterogeneous reaction occurs only. Competition of the gas phase reaction, the heterogeneous reaction and the metal evaporation is the reason for the sharp transition from one to another regime.

Key words:

• Combustion
• particle
• magnesium
• carbon dioxide
• fuel
• Mars