Multiscale modelling of packed bed chemical looping reforming

Abstract

A comparison of reactive flows on two distinct scales is presented here (i) Particle resolved direct numerical simulation (PR-DNS), and (ii) 1D packed bed model. The PR-DNS geometry is meshed with polyhedral elements both inside and outside the particle to directly resolve the phenomena of intra particle diffusion and external heat and mass transfer. In contrast, the 1D packed bed model incorporates appropriate closure models to compare against the PR-DNS solutions at a computational cost several magnitudes less. Simulations are performed for endothermic steam methane reforming reactions (SMR) over a range of inlet temperatures. The comparison of the results between the two approaches shows that the 1D model can adequately replicate the PR-DNS results with appropriate modifications to the closures. The resulting verified 1D model was then used to simulate the reforming stage of an industrial scale packed bed chemical looping reforming reactor.