The development of oxygen carrier and rational design of fluidized reactor are two key technologies for biomass chemical looping gasification (BCLG) process. In order to understand the characteristics of BCLG, the reactor system has been developed from the initial TGA, fixed bed reactor, to small-scale fluidized bed, and now extended to a sub-pilot fluidized bed. BCLG is still in the stage of laboratory research at present, lacking kinetic data of long-term continuous operation. In order to achieve good fluidization and gas sealing between two interconnected reactors, this paper reported a cold system, which is designed according to experiment kinetic and thermodynamic calculation. This system was evaluated by using quartz sand as bed materials and air as fluidizing medium. Based on the success of cold experiment, a hot BCLG system has been deployed in Qingdao Institute (as shown below), which consists a bubbling fluidized bed gasifier and a circulating fluidized bed reactor. The hot experiments on chemical looping gasification of walnut shell were performed with hematite/ BaFe₂O₄, and the experimental results showed that BaFe₂O₄ demonstrated excellent reactivity and selectively for biomass gasification. The effective gas (CO+H₂+CH₄) composition is more than 80%, and heat valve is between 13-14MJ/Nm³, which demonstrate significant potential of BCLG for commercial applications.
 

BCLG (Biomass chemical looping gasification), interconnected circulating fluidized bed reactor, bimetallic oxygen carrier