The effect of ethane on the chain reaction characteristics of methane–air mixtures explosions

In order to study the effect of ethane on gas explosions, the macroscopic properties, thermodynamics and kinetics of gas explosions were investigated using Chemkin numerical simulation software with the GRI-Mech 3.0 mechanism. Ethane was added to methane-air mixtures at seven different concentrations, such as 0%, 0.1%, 0.3% and so on, at constant initial temperature (1200 K) and pressure(0.9atm), respectively. The results show that the maximum explosion pressure, explosive power and ·H content was all maximized when the volume fraction of ethane was 3%, which was the most effective volume addition to promote gas explosion. Ethane reduced the time to peak energy of key radical reactions from 0.049s to 0.003s and reduced the sensitivity factors for reactions such as R155 and R158. When the added ethane was 8%, R158 and R98 shifted from inhibiting methane consumption to promoting methane consumption. Calculated by Arrhenius and Lindemann formulae found that ethane can act as the third molecule in unimolecular reactions, increasing the reaction rate constant and decreasing the activation energy, so accelerating the reaction. Due to the low addition of ethane, there was still a large amount of N₂ acting as the third molecule, so the decrease in activation energy was small.