Transient Cold Flow Simulation of a Fast Fluidized Bed Fuel Reactor for Chemical Looping Combustion

Abstract

Circulating fluidized bed (CFB) in chemical looping combustion (CLC) is a novel carbon capture technology which offers great advantage for high efficiency and low cost. To obtain a thorough understanding of the hydrodynamics behavior inside the reactors as well as CLC process, numerical simulations are conducted. Computational fluid dynamics (CFD) simulations are performed with dense discrete phase model (DDPM) to simulate the gas–solid interactions. CFD commercial software ANSYS Fluent is applied for the simulations. Two bed materials of different particle density and diameter, namely the molochite and Fe100, are used in studying the hydrodynamics and particle behavior in a fuel reactor corresponding to the experimental setup of Haider et al. at Cranfield University in U.K. Both the simulations reach satisfactory agreement with the experimental data concerning both the static pressure and volume fraction at various heights above the gas inlet inside the reactor. It is found that an appropriate drag law should be used in the simulation depending on the particle size and flow conditions to obtain accurate results. The simulations demonstrate the ability of CFD/DDPM to accurately capture the physics of CFB-based CLC process at pilot scale which can be extended to industrial-scale applications.