INFLUENCE OF NON-ISOTROPIC DIFFUSION ON EFFECTIVE REACTION RATES IN CATALYST PARTICLES

TAULAMET, M.J.; MARTÍNEZ, O.M.; BARRETO, G.F.; MARIANI, N.J.

LATIN AMERICAN APPLIED RESEARCH

Plapiqui

Lugar: Bahia Blanca; Año: 2023 vol. 53 p. 59 - 64

0327-0793

The non-isotropic diffusion and reac-tion problem in cylindrical particles of different cross-sections is analyzed in this contribution employ-ing the one-dimensional Generalized Cylinder Model (1D-GCΓ). Such a model presents a single parameter of straightforward calculation from the geometrical magnitudes of the catalyst particles. Different but uni-form values of axial and transversal effective diffusiv-ities are assumed. The performance of the 1D-GCΓ model for the effectiveness factor estimation is as-sessed for a variety of particle shapes and a set of ki-netic expressions. Maximum errors in the predictions, varying a Thiele modulus and the axial-to-transversal diffusivities ratio, are below 6% for the first order re-action and rise up to around of 9% and 11% for a LHHW (Langmuir-Hinshelwood-Hougen-Watson) expression at the verge of the appearance of multiple steady states, in the case of Raschig rings and solid circular cylinders, respectively.