Low Reynolds number isotope transient kinetic modeling in isothermal differential tubular catalytic reactors

Abstract

A novel method is presented for modeling steady state isotope transient kinetics of heterogeneous catalytic reactions when the flow regime is laminar and conversion is differential. It is based on a factorization theorem which is deduced from the observation that transport functions fluctuate radially in porous beds. Factorization separates the radial from axial and temporal coordinates of the flow rate and concentration functions. It is shown that in transient tracing with a differential conversion, the radial components of the transport functions in the material conservation equations can be integrated into constant parameters to be determined from experimental data. The method is in particular useful as the knowledge of the radial profile of velocity and other transport functions and parameters are not prerequisites for data correlation. The methodology was successfully applied to the adsorption of carbon monoxide in Boudouard reaction on an alumina supported palladium catalyst. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1317–1329, 2018

Area averaging of packed bed in continua conservation equations in axial flow

“…An average model for steady state isotope transient tracing provides a method for studying the mechanism of catalytic reactions under favourable operating conditions of lower Reynolds numbers. [ 14 ] Such averaging is advantageous because otherwise tracing experiments should be performed either in rapidly recirculating continuously stirred tank reactors or in tubes under plug flow. Tracing in continuously stirred tank reactors is not valid for mechanisms with reversible steps, [ 15 ] and establishing plug flow is a far reaching ideal.…”