Organic solid waste as sustainable fuels and reducing agents in low-carbon steelmaking technologies

The steel industry, as a representative of high energy consumption and high carbon emission industries, has long pursued energy conservation and emission reduction in its production processes. Organic solid waste, particularly carbon–neutral biomass and waste polymers with high H/C ratios, is one of the most interesting raw materials for the production of renewable energy and holds great potential in low-carbon steelmaking process. This review first elaborates the chemical and physical properties of diverse organic solid wastes and their thermal treatment products, and then focuses on summarizing the application advances of these materials in various stages of the steelmaking process, including but not limited to the sintering and blast furnace (BF) processes in the BF-basic oxygen furnace route and the direct reduction and electric arc furnace (EAF) processes in the EAF route. The pros and cons of the introduction of different organic solid wastes into each process are discussed in detail, especially for the potential of low-carbon and energy-saving steelmaking. And the future perspectives and challenges associated with this field are also presented. This review aims to provide an overall view of the utilization of organic solid waste in the steelmaking process and motivate further development of low-carbon metallurgical industry.