From full–range pore analysis to CFD simulation: A joint experimental–numerical study of an industrial OCM catalyst

The hierarchical pore structure of industrial catalyst particles, spanning nanometers to hundreds of micrometers, eludes any single technique. This study, for the first time, integrates four complementary methods—scanning electron microscopy, N 2 physisorption, mercury intrusion porosimetry, and x–ray micro–computed tomography (micro–CT)—to systematically characterize an oxidative coupling of methane (OCM) catalyst. A full–range pore model is constructed, revealing a multimodal differential pore volume distribution and a radial gradient: both porosity and average pore size decrease from the particle center toward the periphery. Using these parameters, a single–particle computational fluid dynamics (CFD) model is developed, coupling mass, momentum, and heat transfer with kinetics. The simulation yields an effectiveness factor of 0.639, indicating moderate internal diffusion limitations. This work demonstrates that micro–CT enables quantitative 3D pore analysis of industrial catalysts and that the experimentally observed non–uniform pore distribution is essential for accurate CFD prediction of catalyst performance.