Computational Particle-Fluid Dynamics Simulation of Gas-Solid Flow in a Circulating Fluidized Bed with Air or O2/CO2 as Fluidizing Gas

Authors: Mukesh Upadhyay ^a, Hoon Chae Park ^a, Jae Gyu Hwang ^a, Hang Seok Choi ^a, Ha-Na Jang ^a, and Yong-Chil Seo ^a
a Department of Environmental Engineering, Yonsei University, Wonju, Gangwon-do 26493, Republic of Korea

Source: Upadhyay, M.; Park, H. C.; Hwang, J. G.; Choi, H. S.; Jang, H.-N.; Seo, Y.-C. Computational Particle-Fluid Dynamics Simulation of Gas-Solid Flow in a Circulating Fluidized Bed with Air or O 2 /CO 2 as Fluidizing Gas. Powder Technology 2017, 318, 350–362.

Abstract: Computational particle-fluid dynamics (CPFD) simulation was carried out to examine the influence of air versus O₂/CO₂ as the fluidizing gas on the hydrodynamics of gas-solid flow in a cold-mode circulating fluidized bed. The CPFD simulation results were compared to the experimental data at constant superficial gas velocity, using air or mixed O₂/CO₂ in three different concentrations as the fluidizing gas. The simulation results showed that the model successfully captured the experimentally observed trends. A detailed statistical analysis was carried out on the transient pressure data, and results were found to vary depending on whether air or combustion gases (O₂/CO₂) were used for fluidization. In all cases, the flow exhibits a typical core-annular flow structure, although for O₂/CO₂ gas the solid volume fraction increases near the wall region. The CPFD results provided insights into the gas-solid flow behavior in a fluidized bed combustor riser under an oxy-fuel fluidizing atmosphere.