Direct reduction of oxidized iron ore pellets using biomass syngas as the reducer

The syngas derived from a pyrolysis and gasification process was used as a reducing agent to produce iron ore pellets. The reduction temperature was kept between 1123K and 1323K, and the time was set 30min. Results showed that the reducibility increased from 88.1% at 1123K to 99.95% at 1323K. The reduction rate increased with increasing reduction temperature. Further, the reaction rate in the early stage was higher than that in the later stage. The X-ray diffraction (XRD) and metallographic microscope analyses of the oxidized pellets and direct reduced iron (DRI) products showed that, the reduction process followed the reaction scheme: Fe2O3→FeO→Fe. A kinetics analysis indicated that, the reduction rate was controlled by an interfacial chemical reaction with syngas and that the activation energy was 104.76kJ/mol. The effect of syngas as the reducing gas on the reduction of iron ore pellets was similar to that of natural gas. The use of biomass during DRI production can eliminate CO2 emissions, energy crisis, and climate change. •The reduction process followed the chemical interfacial reaction mechanism.•The rate controlling reaction is FeO→Fe.•The DRI production process can be carried out with no net CO2 emission.