Probing pore blocking effects on multiphase reactions within porous catalyst particles using a discrete model.

A discrete model coupling mass transfer, reaction, and phase change in porous catalyst particles is proposed to probe pore blocking effects on multiphase reactions. This discrete model is validated by comparing the results with experiments and those obtained using a continuum model, for the hydrogenation of benzene to cyclohexane in Pd/γ-alumina catalyst particles. The results show that pore blocking has a significant effect on the effectiveness factor and can contribute to up to 50% of the hysteresis loop area for multiphase reactions in porous catalysts, indicating that pore blocking must be accounted for. Moreover, the pore blocking effects are significantly enhanced when the pore network is poorly connected and the pore-size distribution is wide, while the pore blocking effects are insensitive to the volume-averaged pore size. Multiphase catalyst material characterization and design should account for this effect. © 2015 American Institute of Chemical Engineers AIChE J, 62: 451-460, 2016 [ABSTRACT FROM AUTHOR]