Combustion mechanism of benzene in iron ore sintering process: experimental and simulation

Benzene is a typical component of volatile organic compounds (VOCs) in the iron ore sintering flue gas. The combustion behavior of benzene directly affects the emission of VOCs in iron ore sintering process. The effects of temperature, benzene, and oxygen concentrations on the conversion ratio of benzene were investigated by experiments and numerical simulation. The experiments were carried out in a tube reactor at temperatures of 773–1098 K, benzene concentrations of 0.01–0.03 vol.%, and oxygen concentrations of 10–21 vol.%. The numerical simulation was performed with the plug flow model in the CHEMKIN program based on a kinetic model that consists of 132 chemical species and 772 elementary step-like reactions. The experimental results reveal that increasing the temperature and benzene concentration could significantly promote benzene combustion. It is attributed to the increase in the reaction rates of all steps in the pathway for forming CO 2 and H 2 O. In addition, due to the large equivalent ratio of oxygen to benzene, the conversion ratio of benzene remained constant at different oxygen concentrations. The simulation results were in good agreement with the experimental results and indicated that six elementary reactions dominated the formations of CO 2 and H 2 O. The oxidations of C 6 H 5 O, CO, and C 5 H 4 O intermediates to CO 2 were the limiting steps in the reaction pathways.