A MULTI-DOMAIN 1D PARTICLE-REACTOR MODEL FOR PACKED BED REACTOR REACTOR APPLICATIONS

Abstract

A validated multi-domain 1D particle-reactor model has been developed to simulate packed bed reactor operation. Two main components of the model are: (1) a particle model for simulating the radial distribution of chemical species and temperature within the catalyst particles and (2) a 1D reactor model for solving mass and energy transport along the length of the reactor. The model captures the effect of intra-particle heat and mass transfer phenomena on the reactor performance. Its efficacy and usability is evaluated using a thorough verification and validation campaign. Validation has been carried out through comparisons to analytical solutions for: (a) the transient thermal response of the fixed bed to a step-change in inlet feed temperature and for (b) the maximum temperature rise during an exothermic oxidation process in a chemical looping combustion (CLC) operation. Further, its performance has been verified with two well-established solvers (a 1D Euler- Euler packed bed model developed in ANSYS FLUENT and a previously published 1D model) for simulating a realistic 500kW cyclic packed bed chemical looping combustion system involving dynamic fuel-air cycling. This successful verification demonstrates the ability of the model to simulate complex cyclic packed bed reactor processes involving stiff kinetics in an efficient manner. Further, significance of particle model is evaluated for mass transfer limiting condition and this reinforces the advantage of using the proposed 1D particlereactor model in such cases.