The combustion mechanism of aluminium in the steam/carbon dioxide mixed atmosphere

Abstract

The ignition and combustion characteristics of aluminium (Al) in the steam/carbon dioxide (H₂O/CO₂) mixed atmosphere were calculated by using a close homogeneous catch reactor and premixed laminar flame-speed of CHEMKIN-PRO. The effects of initial reaction temperature and H₂O/CO₂ ratios on the system temperature, products, and ignition delay time were explored. The main reaction paths were analyzed by the temperature sensitivity. Al (l) entered the system with a pronounced phase transition and only one heating stage, but there are two heating stages in the Al (g) system. The reaction of Al in the H₂O/CO₂ mixed atmosphere has a positive effect on the ignition delay time of the system. The high contents of CO₂ in the H₂O/CO₂ mixed atmosphere can increase the maximum temperature of system and decrease the ignition delay time. Temperature sensitivity analysis shows that AlO, Al₂O, and AlOH are important intermediate products, and Al₂O₂ is the main substance that produces Al₂O₃. The dominant reaction path is Al → AlOH→AlO → Al₂O → Al₂O₂ → Al₂O₃. In addition, when the initial temperature was 2300 K, the laminar flame velocity was calculated to reach 35.6 m/s.