Design and operation of a multi-stage reactor system for chemical looping combustion process

Abstract A chemical looping combustion (CLC) system with a multi-stage fuel reactor (FR) and a two-stage air reactor (AR), was constructed and operated in an experimental study and simulated via the computational particle fluid dynamics (CPFD) method. Hydrodynamic results with a bubble-based EMMS drag model agreed well with the experimental measurements. The wall effect in the small-scale AR led to an uneven particle distribution and irregular fluidization at a small NAR. The bubble size and velocity were limited in the FR, thereby significantly boosting the gas-solid contact. The particle residence time in the FR was prolonged, resulting in a high carbon capture rate. With the increase in fluidization number in FR and AR, the mass flux increased, but the residence time decreased. Adding a secondary gas flow in the FR has a positive impact on the solid circulation rate. The results in the thermal test indicated that a high CO2 capture rate and a low oxygen demand were achieved; thus the proposed reactor design improved the fuel conversion in the CLC process.