In the present work, the gas–solid flow in a vertical pipe was considered in order to analyze it numerically. The Eulerian–Eulerian two-phase model was used to predict the pressure drop in a 30-mm-diameter vertical pipe, in which the length was equal to 100 times the diameter. The particle size was varied from 30 to 200 μm and the solid loading ratio was varied from 1 to 10. Inter-particle collisions were considered by taking into account four-way coupling, which gives rise to solid pressure terms and these terms are closed using kinetic theory of granular flows. The effect of numerical parameters such as the restitution and specularity coefficients and drag models on the pressure drop was investigated. It was observed that the value of the specularity coefficient strongly affects the pressure drop prediction and has to be selected properly; the other parameters do not significantly affect the prediction of the pressure drop.