New technology for producing high-quality combustible gas by high-temperature reaction of dust-removal coke powder in mixed atmosphere

Abstract Converter high-temperature flue gas (CHFG) is an important energy source, but it contains a low concentration of combustible gas and its use produces significant CO2 emissions. We propose a method for increasing the combustible gas concentration of CHFG, which involves injecting dust-removal coke powder (DRCP) into CHFG and catalyzing their reaction with metal oxide. The presented technology not only converts CO2 into combustible gas CO but also provides a new direction for efficient and clean utilization of DRCP. It is theoretically based on thermodynamic calculations (FactSage 6.1) and thermal analysis experiments, and its feasibility is verified through dropper furnace (DF) and industrial experiments. The phase composition is characterized by scanning electron microscopy coupled with energy-dispersive X-ray analysis, X-ray diffraction, and X-ray fluorescence. The results show that the initial decomposition temperature, the maximum decomposition temperature, and the final decomposition temperature of the DRCP gasification reaction are all reduced after adding metal oxide. The CO, H2, and CH4 contents in the high-temperature flue gas increase, whereas the CO2 content decreases. In addition, the reduction products with the addition of CaO are mainly CaO and a small amount of CaCO3. However, the reduction products when Fe2O3 and FeO are added mainly include Fe and Fe3C. Simultaneously, the addition of metal oxide can increase the gasification reactivity of DRCP. After the DRCP is injected, the combustible gas concentration and recovery time are obviously improved. The feasibility of the proposed technology is systematically verified through a series of experiments. This technology provides an innovative solution for converting industrial waste gas into valuable resources using industrial solid waste.