The development of exothermic surface reaction between coal and oxygen affected by methane during coal spontaneous combustion in gob

Abstract

Coal spontaneous combustion (CSC) derives from the exothermic coal-oxygen reaction occurring at coal's surface. However, methane's influence on this process is still unclear in gob environments. To this end, non-isothermal experiments were performed to elucidate methane's impact on the exothermic effect, pore structure evolvement, and surface composite variation in CSC. Our findings indicated that methane inhibited the exothermic effect; however, low methane (50 %) methane concentrations, because coal lay in oxygen-rich and fuel-rich oxidation states, respectively. Methane's influence on exothermic reaction originates from competitive adsorption. Methane competes with oxygen and other gases for adsorption sites. This changes the surface properties and affects the competitive adsorption between methane and other gases. This study can provide valuable insights for mitigating CSC risk.

Keywords

• Exothermic surface reaction
• Coal spontaneous combustion
• Surface elements
• Reaction heat
• Activation energy