| Abstrakt: |
The goal of this study was to investigate the reaction mechanisms linked with the oxy-fuel combustion of ethanol (C2H6O). The oxidation of ethanol in O2/N2and O2/CO2environments was examined using reactive molecular dynamics in the temperature range from 2200 to 3000 K at constant density media and O2/fuel ratio equals to 0.5. The main reactions were examined to supply a description of the ethanol oxidation behavior, the main product distribution, and the corresponding time evolution behavior in the atomic scale. It has been noted that the oxidation of C2H6O was initiated mainly from the same routes in both environments generating the same main species. However, the key reaction pathways were different depending on the media. We noticed an increase of CO formation when N2was replaced by CO2molecules, increasing the net flux of the following reactions: by CO2+ H → CO + OH and CO2+ CHO → O═COH + CO. This work also studied the effect of increasing O2concentration (O2/fuel ratio equals to 0.5, 1.0, and 2.0) in O2/CO2combustion. During the simulations, high oxygenated and unstable species were detected such as carbonates and carboxyl radicals. The change of the O2/fuel ratio from 0.5 to 2.0 lead to an increase of CO2formation mainly from O2+ O═COH → CO2+ HO2and O2+ CO → CO2+ O reactions. In addition, the increase of O2concentration attenuated the effect of CO2and could increase the occurrence of reactions that lead to flame cessation. |
