Modeling of the chemical-looping combustion of methane using a Cu-based oxygen carrier

A mathematical model for a bubbling fluidized bed has been developed to simulate the performance of the fuel reactor (FR) in chemical looping combustion systems. This model considers both the hydrodynamic of the fluidized bed (dense bed and freeboard) and the reduction kinetics of the oxygen carrier (OC). The main outputs of the model are solid conversion and gas composition at the reactor exit, the axial profiles of gas composition, and the fluidynamics structure of the reactor. The FR model was validated using the experimental data obtained from the CH4 combustion in a 10 kWth prototype built at the “Instituto de Carboquímica” (ICB-CSIC, Spain) using a Cu-based OC. The influence of OC circulation rate, fuel gas load, reactor temperature and OC particle size were analyzed. Combustion efficiency predicted by the model showed a good agreement with experimental results. Once the FR model was validated, important consequences for the design and optimization of the FR in a CLC system were obtained.