Study on the feasibility and co-combustion mechanism of mixed injection of biomass hydrochar and anthracite in blast furnace

Abstract

Under the energy saving and emission reduction pressure, biomass has attracted much attention from metallurgical workers because of the renewability and zero CO2 emission characteristics. In this paper, the physical and chemical properties of biomass residue hydrochar (BRC) and Yangjing pingding anthracite (YAC) were systematically studied by X-ray diffraction, scanning electron microscope and Raman spectroscopy. Moreover, the combustion characteristics and mechanism of biomass residue (BR), BRC, YAC, and the mixtures of BRC and YAC were studied by thermogravimetric analysis experiments. The results show that BR has a high volatile content of 82.26% and contains a large amount of alkali metals, but BRC has a low alkali metal content. The carbon atom sequence degree and graphitization degree of BRC are lower than that of YAC. The BRC particles also have a well-developed pore structure, and the reactivity of BRC is higher than that of YAC. The addition of BRC to YAC can improve the combustion performance of YAC. There is an obvious synergistic effect in the combustion process of the mixed sample. The kinetic model was used to fit the combustion reaction, and it was found that the random pore model (RPM) showed a more accurate fitting result. When the ratio of BRC is 60%, the activation energy of the mixed sample is 38.5 kJ/mol, which has superior combustion characteristics in raceway of blast furnace.