Volatile organic compounds (VOC) emissions control in iron ore sintering process: Recent progress and future development

The iron ore sintering, an energy-intensive industry, contributes to large emissions of Volatile Organic Compounds (VOCs) due to its high dependence on fossil fuels. The emissions of VOCs from the iron ore sintering process have been ignored until now, despite the well-documented atmospheric and human health hazards associated with VOCs. The mechanisms of VOC emissions during sintering process are discussed. The incomplete combustion of ignition gases and coal/coke particles in the sintering mix is the main cause of VOC emissions. In fact, the low concentration of VOCs in sintering flue gas masks the truth about the immense amount of VOC emissions. This review highlights the real and non-negligible risk of atmospheric pollution by VOCs from sintering sources, as well as the urgency to awaken researchers and policy makers. The authors explore feasible pathways to control VOCs based on current commercially applied sintering flue gas treatment technologies. Meanwhile, this article briefly outlines a range of major technologies, methods, processes, and materials available for the VOC emissions control of industrial flue gases, and focuses on catalytic combustion for VOC treatment, in particular the development of perovskite-type catalysts, such as selection, design, modification, loading, etc. Great promise has been demonstrated in applying perovskite catalysts in removal of VOCs from flue gas over the years, but developing highly active perovskite-type catalysts with anti-toxicity and long-time stability requires additional efforts. The sintering flue gas VOCs face a variety of challenges in terms of policy regulation, financial investment, basic materials research, and commercial solutions. Remarkably, it is vitally important to explore the possibility of synergistic oxidation of VOCs, NOx, and PCDD/Fs by exploiting the high oxidation properties of perovskite materials.