In this study, highly exothermic reactions of methane in a turbulent fluidized bed (TFB) reactor of sand particles were investigated. Natural gas with air fed separately into the reactor was chosen as a sample reaction to represent the highly exothermic reactions. An equation-oriented model is also developed for the combustion of highly exothermic reactions in a fluidized bed reactor of inert particles. The proposed model integrates bed-sparger hydrodynamics and reaction submodels necessary to model the combustion phenomena. The hydrodynamic submodel is derived from our experimental studies as well as using information from the literature. The kinetic submodel, which includes the inhibition phenomena, was obtained from the combustion literature. These submodels are then combined together so that the TFB may be represented. The validity of the model was demonstrated using different sets of operating conditions for a pilot TFB reactor, and satisfactory agreements were obtained.