Vol.:(0123456789) Reaction Kinetics, Mechanisms and Catalysis https://doi.org/10.1007/s11144-020-01822-8 1 3 Study of efectiveness factors with non‑uniform catalyst distributions for methane steam reforming Ignacio Iglesias 1  · Eduardo Poggio‑Fraccari 1  · Pablo Giunta 1 Received: 27 April 2020 / Accepted: 9 July 2020 © Akadémiai Kiadó, Budapest, Hungary 2020 Abstract In the present work, three kinetic expressions for methane steam reforming with diferent methane and water partial pressures dependence were studied. Methane efectiveness factors were simulated for spherical uniform pellets (those customarily employed), for several temperatures and water/methane ratios (hereafter called R). It was found that all efectiveness factors decreased with temperature as expected for all the kinetics expressions studied. On the other hand, the evolution with R was strongly dependent on the kinetics analyzed, with an important change in efective- ness factors values, ranging from 30 to 400%. This implies that the most conveni- ent active sites distribution might be dependent on R evolution throughout the reac- tor. Then, two MSR reactors were simulated, loaded with pelletized catalysts with uniform and eggshell in order to get uniform nomenclature active site distributions. It was found that the one loaded with eggshell in order to get uniform nomencla- ture pellets saves up to 30% catalysts mass with respect to the uniform catalyst dis- tribution for the same CH 4  conversion, reinforcing the importance of active sites distribution. Keyword Methane steam reforming · Non-uniform catalyst distribution · Eggshell · Pellet simulation Abbreviations DFT Density functional theory DRM Dry reforming of methane MSR Methane steam reforming List of symbols C [mol m 3 ] Molar concentration * Eduardo Poggio-Fraccari eduardoaristidespf@di.fcen.uba.ar 1 Instituto de Tecnologías del Hidrógeno y Energías Sostenibles, ITHES (UBA-CONICET), Pabellón de Industrias, Ciudad Universitaria, 1428 Ciudad Autónoma de Buenos Aires, Argentina