Parametric sensitivity analysis of the transient adsorption-diffusion models for hydrocarbon transport in microporous materials

Abstract

The complex nature of hydrocarbon transport in microporous materials offers unique challenges for the description of transient kinetic data in catalysis by e.g. acidic zeolites and zeotypes. Currently, very few models in the literature capture such phenomena as surface barriers or hindered microporous diffusion - processes that are known to impact gas transport during the kinetic studies of zeolite catalyzed reactions. In this work we provide extended models that reflect the aforementioned phenomena during pulse-response experiments in the Temporal Analysis of Products (TAP) reactor. Systematic studies of models’ parametric sensitivity are presented to assist the design of future experiments. Numerical simulations are used to investigate how thermodynamic adsorption properties of realistic zeolites can affect the pulse-response shapes. For certain combination adsorption/diffusion parameters, microporous diffusion is shown to result in a characteristic bend in the mean residence time temperature dependency, which can be used as a fingerprint in model discrimination.