In this paper, a mathematical model is developed to calculate the conversion and the residence time reaction for plug flow and mixed flow in the reactors filled with cylin-drical particles using the shrinking core model. In this modeling, the size of the particles is un-chamged during the reaction. Also, the reaction rate is controlled by the gas layer resistance, the ash layer resistance, and the reaction resistance as well as the combination of them. In addition, it is assumed that the gas diffuses radially from the side, whereas the effect of diffusion in the axial direction is neglected. Equations are solved by numerical methods. It can be said that the innovation of this paper is the study of the effect of combination of resistances on the conversion of the reaction. Model evaluation shows that the results of modeling have a good consistency with the experimental data. The results show that at a certain time, when the rate of reaction is controlled by each of the resistances individually, the conversion rate is greater when the reaction is controlled by the ash layer resistance than when it is controlled by the other two resistance regimes. Finally, the effect of the combination of different controlling regimes on the conversion and residence time of reaction for plug flow and mixed flow of particles is studied and it is found that the overall results are similar to each other.