Cold-flow Model Experiment of Interconnected Fluidized Bed for Chemical Looping Combustion of Coal

Taking the configuration of "turbulent bed + fast fluidized bed" as the air reactor (AR) and a bubbling bed as the fuel reactor (FR), a coal-fueled chemical looping combustion (CLC) system was designed, where two loopseals are used to prevent gas leakage between AR and FR, and a cyclone for gas-solid separation. Cold-flow model experiments were carried out to study the pressure distribution, solids circulation rate, gas leakage rate and ash-carrier separation efficiency of the CLC system. Results show that for the interconnected fluidized bed, its AR and FR are well sealed; the solids circulation rates meet or even exceed the design requirement; the separation efficiency of secondary cyclone at the FR exit nearly reaches 100%; the mass fraction of coal ash entering into AR from FR is less than 1.55%; the coal ash separation efficiency is high. The experimental setup may operate stably and continuously for a long time in a wide range of controllable gas superficial velocities, proving it to be feasible to design and operate the interconnected fluidized bed for coal-fueled chemical looping combustion.