Transient Reacting Flow Simulation of Spouted Fluidized Bed for Coal-Direct Chemical Looping Combustion

Abstract

Coal-direct chemical-looping combustion (CD-CLC) is a next generation combustion technology that shows great promise as a solution for the need of high-efficiency low-cost carbon capture from fossil fueled power plants. To realize this technology on an industrial scale, the development of high-fidelity simulations is a necessary step to develop a thorough understanding of the CLC process. In this paper, simulations for multiphase flow of the CD-CLC process with chemical reactions are performed using ANSYS Fluent computational fluid dynamics (CFD) software. The details of the solid–gas two-phase hydrodynamics in the CLC process are investigated using the Lagrangian particle-tracking approach called the discrete element method (DEM) for the movement and interaction of the solid oxygen carrier particles with the gaseous fuel. The initial CFD/DEM simulation shows excellent agreement with the experimental results obtained in a laboratory scale fuel reactor in cold-flow conditions at Darmstadt University of Technology. Subsequent simulations using 60% Fe2O3 supported on MgAl2O4 reacting with gaseous CH4 demonstrate successful integration of chemical reactions into the CFCD/DEM approach. This work provides a strong foundation for future simulations of CD-CLC systems using solid coal as fuel, which will be crucial for successful deployment of CD-CLC technology from the laboratory scale to pilot and industrial scale projects.