Review on the progress of hydrogen-rich gas injection into blast furnace

Currently, the steel industry’s primary focus is on energy conservation and emission reduction, with blast furnace ironmaking contributing the largest share of carbon emissions in the steel production process. From an energy perspective, it can effectively reduce energy consumption and carbon emission through injecting renewable clean energy such as hydrogen into the blast furnace to replace part of coke and pulverised coal. This paper investigates and discusses the process of injecting hydrogen-rich gas into blast furnaces, the fundamental mechanism of reducing iron oxide with hydrogen, the current global application trends, and the future outlook for hydrogen-based metallurgy. The carbon emission reduction and economic calculation of hydrogen-rich gas injection technology in blast furnace are also introduced. The main types of hydrogen-rich gas injection include natural gas (NG) and coke oven gas (COG), among which COG is widely used in China and has significant CO 2 emission reduction effects. The proportion of H 2 addition is limited by furnace conditions, because the skeleton function of coke in the blast furnace cannot be replaced. At the same time, excessive addition of H 2 can decrease the upper part temperature of the blast furnace, causing furnace cooling and hindering the smooth flow of gas. Currently, hydrogen-rich blast furnaces have been put into use in some regions of the world and have achieved certain carbon reduction results. The injection of hydrogen-rich gas into blast furnaces holds significant potential for future development.