Comprehensive study on the reduction of biomass embedded self-reducing pellets (SRP) under H2 involved conditions by TG-DTA

Abstract

Application of biomass embedded self-reducing pellets (SRP) in the Hydrogen direct reduction (H-DR) process is expected to solve the problem of low/zero carbon content in the DRI product of H-DR. In this study, reduction of biomass embedded SRP by N2/H2/CO at different temperatures was conducted by using Thermogravimetric/Differential Thermal Analyzer (TG/DTA), Scanning electron microscopy (SEM) was used to characterize the microstructure, porosity, and remaining biomass of the reduction product. Results show that: the reduction of iron ore by biomass starts at about 400 °C; the activation energies of H2 reduction in the initial and final stages are 2.54–4.68 kJ/mol and 56.69–85.36 kJ/mol, respectively; addition of biomass in pellets could ensure the carbon content and porosity of the reduction product; besides, reduction of 12% biomass pellets at 950 °C and 40% H2–60% N2 atmosphere is considered as the optimal reduction condition in this study, the final relative mass loss is 97.90%.