CFD Simulations of Complete Circulating Dual Fluidized Bed Systems forChemical Looping Combustion

Abstract

Chemical-looping combustion (CLC) is a next generation combustion technology that shows great promise in addressing the need for high-efficiency low-cost carbon capture from fossil fueled power plants. Although there have been a multitude of experimental studies on CLC in recent years, the number of CFD simulations in the literature has been more limited. In this paper, simulation of a CLC reactor is developed using the Eulerian approach in the commercial CFD solver ANSYS Fluent based on a laboratory-scale experiment with a dual fluidized bed CLC reactor to model the chemical reactions in the system. The solid phase consists of a Fe-based oxygen carrier while the gaseous fuel used is syngas. Later, the detailed hydrodynamics in a CLC system designed for solid coal fuel are studied based on a cold flow experimental setup at National Energy Technology Laboratory using the Lagrangian particletracking approach. To the authors’ knowledge, this work is among the very few CFD simulations of a complete circulating dual fluidized bed system for CLC in three-dimension. It highlights the importance of 3-D simulation of CLC systems and the need for more accurate empirical reaction rate data for future CLC simulations.