Chemical Engineering Journal, Vol.321, 584-599, 2017
A simple approach to describe hydrodynamics and its effect on heat and mass transport in an industrial wall-cooled fixed bed catalytic reactor: ODH of ethane on a MoVNbTeO formulation
The incorporation of hydrodynamics in an industrial wall-cooled packed bed reactor model is essential to describe the performance of highly exothermic oxidation reactions. Although the conventional hydrodynamic approach (CHA), Navier-Stokes equations coupled totechnology to perform the oxidative dehydrogenation of ethane on a multimetallic MoVNbTeO formulation. This is the first study modeling this reactor system accounting for hydrodynamics, information that is essential for its conceptual design in future studies. Finally, it is worth stressing that the PHA, coupled to the heat transport model or the reactor model, leads to significantly lower computation times than the CHA, which is attributed to the analytical rather than numerical solution of the former. (C) 2017 Published by Elsevier B.V. Darcy-Forchheimer terms, has been the most used approximation to describe velocity profiles in these packed bed reactors, it is itself inconsistent and the computation time for its numerical solution, when coupled to the reactor model, is still demanding. This work is aimed at developing a practical but reliable hydrodynamic approach (PHA) to describe velocity profiles in packed bed reactors presenting a low tube to particle diameter ratio. In this approach, velocity profiles are described at the core and close to the wall of the reactor. The core model makes use of the Darcy-Forchheimer equation (DFE), and the wall model makes use of Navier-Stokes equations (NSE) using an effective viscosity to account for turbulence. The PHA predicts similar results to those obtained by the CHA and properly fits velocity observations from packed beds with a tube to particle diameter ratio (dddp) ranging from 3 to 6. The PHA allows the estimation of both turbulent viscosity (mu(t)) involved in the viscous term of the NSE and parameters influencing viscous (a) and inertial (13) flow resistances in Darcy and Forchheimer terms, respectively. Then, hydrodynamics is coupled to a heat transport model accounting for conductive anisotropy to fit temperature observations in absence of reaction from a pilot-scale packed bed reactor with a dddp = 3.048. Hydrodynamics and heat transfer results are, then, transferred to a pseudo heterogeneous reactor model to simulate the behavior of a novel
Keywords:Packed bed reactor;Hydrodynamics;Heat transfer;Oxidative dehydrogenation of ethane;MoVNbTeO formulation