Demonstration of inherent CO2 separation and no NOx emission in a 50kW chemical-looping combustor: Continuous reduction and oxidation experiment

Publisher Summary The chapter explains a study that seeks to display a chemical-looping combustion system by a continuous reduction and oxidation experiment in a 50kWth chemical-looping combustor with high CO2 selectivity, no side reaction (carbon deposition and/or hydrogen generation), inherent CO2 separation, and no NOx emission. In this study, NiO/bentonite acts as an oxygen carrier particle in the bed material of the chemical-looping combustion system and CH4 and air are used as reacting gases for reduction and oxidation, respectively. NO, NO2, and N2O concentrations are measured to check whether NOx is formed during oxidation and measured CO2, CO, CH4, H2 concentration to show inherent CO2 separation and no side reaction during reduction. It takes more than 3.5 hour to finish the process. Pressure drop profiles in a system loop are maintained steadily throughout the 3.5 hour run and solid circulation between an oxidizer and a reducer remains smooth and stable. By analysis of gases in the exit stream from the system, the study concluded that inherent CO2 separation and NOx-free combustion are possible in the chemical-looping combustion system.