Multiphase Computational Fluid Dynamics Simulation of Air and Fuel Reactors of Chemical Looping Combustion

The current work presents the simulations of the chemical looping combustion process where the detailed hydrodynamic study of the air reactor and the reactions inside the fuel reactor have been carried out simultaneously. Cold flow simulation of air reactor is performed using Eulerian-Lagrangian dense discrete phase model incorporated with the kinetic theory of granular flow while discrete phase model is used for the investigation of reaction inside the fuel reactor. Hematite is selected as an oxygen carrier because of its active nature of being oxidized and reduced easily. A maximum pressure gradient of 181 kPa is observed between the bottom and top regions of the air reactor which shows maximum turbulence effect and chaotic nature of gas-solid flow in these regions. An average pressure gradient of 75 kPa is obtained between the outlet and inlet of the air reactor which is favorable for particle movement. The circulation rate of hematite is stabilized after 75 s of the particle injection in the air reactor. The analysis of reactions inside the fuel reactor shows the complete formation of CO2 and H2O after 20 s of the reactor operation.

Automated summary

This study presents simulations of the chemical looping combustion process with a focus on the hydrodynamic behavior of the air reactor and reactions in the fuel reactor. The results show high turbulence and chaotic flow in the gas-solid regions of the air reactor, as well as favorable pressure gradients for particle movement. Additionally, complete formation of CO2 and H2O in the fuel reactor is achieved within 20 seconds.