Internal reaction in the combustion of a porous carbon particle in air

For the diffusion-kinetic model of combustion of a porous carbon particle in air, the structure of the reaction zone of carbon with reactive gases inside the porous particle is studied. It is shown that, for the given kinetics of reaction of carbon with oxygen, the dependence of combustion rate of the porous particle on its internal surface area is ambiguous, which is related to the strong dependence of the reaction rate of carbon with oxygen on temperature. To obtain an unambiguous dependence, it is necessary to use the kinetic equation for the reaction rate of carbon with oxygen with an activation energy lower than the experimentally determined value.