To improve mine safety and production efficiency, it is essential to thoroughly understand the intrinsic mechanisms by which the mine environment affects methane (CH 4 ) explosions. This study explores the processes of chain initiation and the critical elementary reactions in CH 4 oxidation under varying temperatures and environmental conditions (O 2 /CO/CO 2 /H 2 O) through reactive molecular dynamics simulations. The findings suggest that in CO/CO 2 atmospheres, CO plays a dominant role in initiating the chain reaction for CH 4 explosions. Additionally, as the concentration of CO decreases, the time required to initiate the CH 4 reaction increases. CO 2 engages in the reaction CO 2 + H → CO + OH (R1) at high temperatures, thereby increasing the concentration of highly reactive OH radicals. In CO/H 2 O atmospheres, CO remains a dominant factor in the CH 4 explosion chain initiation, while H 2 O enhances the reaction by increasing OH radical content. In CO 2 /H 2 O atmospheres, the chemical equilibrium effects of CO 2 and H 2 O, along with the third-body effect of H 2 O, collectively inhibit the CH 4 reaction rate at low temperatures and high CO 2 concentrations. However, at higher temperatures, the reactivities of CO 2 and H 2 O are enhanced, generating OH radicals, which accelerates the CH 4 reaction. Furthermore, H 2 O competes with CO 2 for H radicals, inhibiting reaction R1. • The effects of multicomponent gases on CH 4 explosion were explored by ReaxFF-MD. • CO promotes CH 4 explosion by altering chain initiation pathway at low temperatures. • H 2 O promotes CH 4 explosion by increasing the concentration of OH radicals. • CO 2 produces OH radicals and increases the conversion of CH 4 at high temperatures. • The effects of multicomponent gases on CH 4 explosion vary with their mixing ratios.
Du et al. (Wed,) studied this question.