近零碳排电弧炉炼钢工艺技术研究及展望

 中国钢铁工业碳排放占全国总排放比例达16%,减少钢铁工业碳排放是中国政府实现“碳达峰、碳中和”承诺的重要抓手。在碳中和背景下,全球钢铁行业正加速推动技术革新以降低碳排放。提出近零碳排电弧炉炼钢新工艺,从能量来源碳近零、冶炼过程碳近零、原料生产碳近零3个层面开展技术创新,以实现炼钢工序碳近零。在能量来源碳近零方面,提出利用太阳能、风能及谷电等能源昼夜交替补充,能量有效存储及释放、微型智能电网及电弧炉优化供电,实现绿色能源的直接高效利用;在冶炼过程碳近零方面,提出利用氢能烧嘴、无碳发泡剂、CO₂-Ar动态底吹脱氮、熔池内O₂-CaO喷吹脱磷及系统能效评价等关键技术实现非涉碳冶炼;在原料生产碳近零方面,提出利用绿氢直接还原炼铁及相关配套技术、绿电等离子热风窑炉配合碳捕集工艺等大幅降低原辅料生产过程碳排放。对电弧炉炼钢过程能量输入、冶炼涉碳及原料带碳的吨钢坯二氧化碳排放进行了衡算,并结合上述关键技术减碳能力分析,计算预测该近零碳排电弧炉炼钢新工艺最终极限碳排放可降低到64 kg/t(钢)。因此,开展近零碳排电弧炉炼钢工艺研究,加速其工业落地应用,将有助于促进中国钢铁工业创新发展和绿色低碳发展。

Research and prospect of EAF steelmaking with near-zero carbon emissions

Carbon emissions from China's iron and steel industry account for 16% of the country's total emissions. Reducing carbon emissions from the iron and steel industry is an important starting point for the Chinese government to realize its commitment of "carbon peaking and carbon neutrality". In the context of carbon neutrality,the global steel industry is accelerating technological innovation to reduce carbon emissions. This paper puts forward a new steelmaking process of electric arc furnace(EAF) steelmaking with near-zero carbon emissions,and points out that technological innovation should be carried out from three aspects: near zero carbon emissions in energy source,smelting process and raw material production,so as to realize near zero carbon emissions in steelmaking process. In the aspect of near zero carbon emissions energy source,it is proposed to use mixed utilization of solar energy,wind energy and valley power,effective storage and release of energy,micro smart grid and optimized power supply to realize the direct and efficient utilization of green energy. In the aspect of near zero carbon emissions in smelting process,the key technologies such as hydrogen burner,carbon free foaming agent,CO₂-Ar bottom blowing for denitrification,submerged O₂-CaO injection for dephosphorization and system energy efficiency evaluation are proposed to realize non-carbon smelting. In the aspect of near zero carbon emissions in raw material production,it is proposed to use green hydrogen direct reduction ironmaking and related supporting technologies,green electric plasma hot blast furnace and carbon capture process to reduce carbon emissions in the production process of raw and auxiliary materials. The energy input in EAF steelmaking process, carbon dioxide emissions from smelting and raw materials production are calculated. Combined with the analysis of carbon reduction capacity of the above key technologies,it is calculated and predicted that the ultimate limit carbon emissions of the new process can be reduced to 64 kg/t. Therefore,it is necessary to carry out research on the EAF steelmaking with near-zero carbon emissions and accelerate its industrial application,which would promote the innovative development and green low-carbon development of China's iron and steel industry.