Evaluating the role of intraparticle mass and heat transfers in a commercial FCC riser: A meso-scale study

► New insights into the FCC fundamental mechanism from the meso-scale viewpoint. ► Intraparticle transfers under FCC reaction conditions. ► A comprehensive particle model is developed. ► A thorough study to the effect of the catalyst position in the riser. ► Three catalytic and reactive operating zones in FCC riser.