Analysis of carbon footprint and reduction approach of magnesia production in China

Abstract

China shares 13.15% and 69.23% of the global magnesite reserves and production respectively. Magnesia is an important connecting link between magnesite and refractory. It is approximately over 80% of magnesite industry that the carbon emitted from magnesia production is directly caused by carbonate decomposition and fossil fuel combustion. Therefore, the study of carbon footprint in magnesia production is valuable for carbon reduction. However, the researches on carbon reduction in magnesia production are rare. In this paper, the carbon footprint method is employed to quantitatively investigate the carbon reduction capacity in magnesia production under the influence of product structure, production process and equipment, and energy source structure. The results show that, for different magnesia, the carbon footprints are 3.937–4.804 kgCO2-eq/kg of fused magnesia, 2.151–3.064 kgCO2-eq/kg of sinter magnesia and 1.440–2.221 kgCO2-eq/kg of light calcinated magnesia at present, respectively. Moreover, for improvement of production process and equipment, the carbon footprint of flash calcinator is 0.489–1.218 kgCO2-eq/kg lower than that of reverberatory furnace for light calcinated magnesia. Similarly, the application of a high-power electricity arc furnace decreases the carbon footprint by 0.763–3.506 kgCO2-eq/kg of fused magnesia. Furthermore, for energy source replacement, the introduction of nuclear power has a carbon reduction capacity of 0.334–2.058 kgCO2-eq/kg-magnesia compared with coal-fired power. It will be 0.473–3.172 kgCO2-eq/kg-magnesia when hydrogen is employed as fuel compared with natural gas and producer gas. Finally, the combination of nuclear power, hydrogen and the carbon capture system will further pull the carbon footprint down to 0.244–0.767 kgCO2-eq/kg-magnesia.