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Estimation of Transport and Equilibrium Parameters on Beta-Zeolites – Tracer Experiments on Packed Bed Reactor Systems

Subramanya Nayak1, Kening Gong2, Bala Subramaniam2, Aldahhan Muthanna1, and M. P. Dudukovic1. (1) Chemical Engineering, Washington University in St Louis, St Louis, MO 63130, (2) Chemical Engineering, The University of Kansas, Lawrence, KS

Three decades of research have shown that a number of solid acid alkylation catalysts display good initial alkylation activity but rapidly deactivates due to build up of heavy hydrocarbons in catalyst pores. By studying the tracer response in packed-bed reactor systems one can estimate adsorption/desorption and effective diffusivities of the reactants and products on supported catalysts. Knowledge of theses parameters allows the optimal catalyst design to enhance the product selectivity, decrease the rate of deactivation, and optimize catalyst regeneration processes. In the current work; a step input of iso-butane or 2-butene in helium is given to a packed beta-zeolite bed at different temperatures and pressures. The model dependent numerical algorithm was used to evaluate the tracer response and to estimate transport and equilibrium parameters. The bed is characterized by using a step response of nitrogen to estimate the bed dispersion coefficient. It was observed that the adsorption and desorption of iso-butane on beta zeolites is non-linear and follows a Langmuir-Hinshelwood type of adsorption isotherm.

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