Overview of Fluidized Bed Reactor Modeling for Chemical Looping Combustion: Status and Research Needs

Modeling of next-generation CO2 capture technology, namely, chemical looping combustion (CLC), in bubbling and circulating fluidized bed reactors is briefly reviewed, and a summary of published mathematical reactor models is presented. The emphasis is on a macroscopic modeling approach, which, aiming at both low computing times and accuracy of results, adopts a phenomenological view and combines transport equations with semiempirical correlations to describe the relevant fluidized bed phenomena, for example, gas–solid flow behavior, reaction characteristics, and thermal effects. Important aspects to be considered in the modeling of CLC in a dual fluidized bed reactor system are highlighted, together with indications of the research needs detected among the reviewed works. So far, semiempirical reactor models have been validated based on experimental results obtained at a larger scale of CLC technology, i.e, up to 0.15 MWth for gaseous fuels (syngas and methane) and up to 1 MWth for solid fuels (mainly coal). Overall, the model predictions agree reasonably well with experiments selected for validation, despite the various model formulations and input data. The research achieved in dynamic process simulation of CLC is very limited.