A mathematical model for carbothermic nitridation of carbon/metal oxide pellet—effect of pressure gradient

A mathematical model has been proposed for describing the carbothermic nitridation of carbon/metal oxide pellet in a stream of nitrogen. Based on the model, dimensionless governing equations were derived to represent the non-isobaric system. Effects of the following five parameters on the conversion of solid C and yield of solid E have been found to be similar to that of an isobaric system: the reaction/diffusion ratio σ2, the reactivity ratios β1 and β2, the reactant amount ratio γ and the Sherwood number NSh. The reaction rate was found to be high when the value of a dimensionless viscous constant B* was large. The reaction rate for the non-isobaric system was generally found to be lower than that for the isobaric system.