Chemical looping combustion (CLC) is a promising technology for CO2 capture, with inherent CO2 separation and low energy consumption. In this study, the reactive multiphase model is incorporated into a computational fluid dynamics code to simulate the reactive fluid dynamics in the CLC reactor with a two-fluid model. The solid friction stress is used to account for the interaction of individual particles with their neighbors through sustained contact at high particle concentrations and the kinetic theory of granular flow is used for closure. Gas-solid flow characteristics and chemical reactions in interconnected fluidized beds using a Cu-based oxygen carrier are simulated. The distributions of solid concentration and gas composition are obtained. The predicted gas compositions at the outlet agree with experimental results. The effects of the operating velocity and the temperature on the combustion efficiencies are also shown. The results demonstrate that a higher bed temperature at a lower operating velocity could enhance the CLC performance.