Direct reduction of iron ore/biomass composite pellets using simulated biomass-derived syngas: Experimental analysis and kinetic modelling

Abstract

This paper presents a novel and environmentally friendly production of direct reduced iron (DRI) technology using biomass as an additive agent in iron ore pellets and simulated biomass-derived syngas as the reducing agent. The effects of biomass addition on iron ore pellets reduction and consequent reduction kinetics in simulated biomass-derived syngas atmosphere were investigated. The results demonstrated that the biomass addition improved the pellet porosity and specific surface area, thus increasing both the reducibility and reduction rate and decreasing the apparent activation energy for pellet reduction. Mathematical modelling of experimental data indicated an interfacial chemical reaction mechanism with FeO→Fe as the rate controlling step. The simulated biomass syngas is an alternative gas-based reductant to natural gas, coal gas, more than 99.5% reduction degree of the oxidized pellets was reduced at 1323K within 20min. The apparent activation energies were 86.05kJ·mol−1, 97.53kJ·mol−1 for the pellets with and without biomass addition. The proposed iron ore reduction process therefore would be a potential to reduce iron directly using biomass with high efficiency and real environmental benefits.