Application status and prospect of low carbon technology in iron and steel industry

China proposes to achieve carbon peaking and carbon neutralization by 2030 and 2060, respectively. As a heavily carbon-based fuel industry, the carbon dioxide emission of the iron and steel industry is lower than that of the power and transportation industries. In 2020, the carbon dioxide emissions of China’s steel industry were approximately 1.98 billion tons, accounting for more than 18% of the national carbon dioxide emissions. To achieve the “carbon neutral” emission reduction target of the steel industry, the three parts of the entire process of steel production, i.e., “source–process–end,” need to be involved in the exploration of low-carbon technologies. This study summarized the low-carbon technology measures of foreign low-carbon dioxide emission projects and major domestic steel companies’ carbon peaking and carbon neutralization projects; divided and classified the low-carbon technologies in today’s steel industry from three levels, i.e., carbon dioxide emission reduction, zero carbon dioxide emission, and negative carbon dioxide emission; and summarized the carbon dioxide emission reduction, maturity, and promotion time of each low-carbon technology. In terms of carbon dioxide emission reduction, carbon dioxide emissions in the production process of the steel industry were reduced by optimizing processes and process reengineering, such as blast furnace top gas circulation technology. In terms of zero carbon dioxide emissions, hydrogen or clean electricity was used to reduce or replace coal or coke with high carbon dioxide emission factors to reduce carbon dioxide emissions from the source, such as hydrogen metallurgical technology. In terms of negative carbon dioxide emissions, carbon dioxide capture was mainly conducted in the high carbon dioxide emission intensity blast furnace ironmaking process, green recycling was performed in the steel plant, and chemical coproduction was implemented outside the plant to produce high value-added chemical products, such as methanol and ethanol. Finally, geological storage of carbon dioxide on steel near the oil field was implemented to reduce carbon dioxide emissions.