CFD simulation of fuel reactor in chemical looping combustion

The combustion is a crucial process for power plant energy production where carbon dioxide (CO2) gas is unavoidably released to the atmosphere. To reduce the greenhouse gas emission, CO2 capturing technology has been employed and led to the reduction of energy efficiency of the energy production system. Chemical looping combustion (CLC) is a novel technology that does not require additional energy for CO2 capture. Therefore, this technology is more environmental friendly. The CLC has two sections connecting each other, air and fuel reactors. In the air reactor, metal is oxidized by the air to produce metal oxide as oxygen carrier. The oxygen carrier is transported from the air reactor to the fuel reactor and combusted directly with fuel. The products of the combustion are heat, carbon dioxide and steam which is easily to separate. High concentration of carbon dioxide is separated from steam by condensation. Finally, the spent oxygen carrier is returned to regenerate in the air reactor and the process is continued as a cycle. In this study, mathematical model was developed for fuel reactor in chemical looping by computational fluid dynamics (CFD) using ANSYS FLUENT. The operating parameters were studied to find the optimum point of syngas conversion. The result showed that at nickel oxide particle diameter of 150 microns, ratio of initial bed height to diameter column about 0.75, syngas temperature of 873 K and 1.5 times of minimum fluidization velocity gives the highest syngas conversion. (C) 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the 2017 International Conference on Alternative Energy in Developing Countries and Emerging Economies.