Recent innovations in chemical looping: Fluidized bed design and oxygen carrier performance

Chemical looping processes are innovative and efficient technologies for hydrogen and chemical production applications. These processes involve the cyclic oxidation and reduction of metal oxide particles within interconnected fluidized bed reactors. The present study provides an overview of the developments in chemical looping fluidized bed reactors and oxygen carriers used for reforming, gasification and hydrogenation. Bed material criteria are considered for both oxygen carriers and feedstocks. An analysis was conducted of the structure and physical properties of the materials and substances, and their performance during complex multi-redox cycles was evaluated. The role of oxygen carriers in various chemical cycling processes and the establishment of a physical standard has been the subject of extensive research. In addition, emphasis was placed on controlling the fluidization regimes within chemical looping processes. For instance, adjusting the fluidizing conditions can yield syngas with up to 70 vol% hydrogen using sorbent-based looping system. This study highlights the importance of constructing particle models that integrate both thermodynamic properties and associated hydrodynamic motions. The implementation of chemical looping processes in fluidized bed reactors is in alignment with the increasing demand for sustainable and low carbon renewable energy technologies, particularly when biomass is used as a feedstock with solar thermal energy for BECCS applications.