Analysis of application technology path of CCUS technology in China's steel industry

Under the "dual carbon" goals, China's steel industry faces severe challenges in deep decarbonization. Carbon capture, utilization and storage (CCUS) is a necessary technical means to address the industry's hard-to-abate carbon dioxide emissions and ensure carbon neutrality. The characteristics of carbon emissions in China's steel industry and the strategic positioning of CCUS technology were systematically expounded. The adaptability of mainstream capture technology paths, such as post-combustion chemical absorption and physical adsorption, to typical emission sources including blast furnace gas and converter gas was analyzed with emphasis. The study finds that the MEA-based chemical absorption method is mature and, with high-efficiency dust removal, can effectively control impurity impacts, making it the most feasible capture route at present. Although ammonia-based absorbents show high theoretical absorption capacity, they suffer from NH₄Cl-induced corrosion and ammonia slip in HCl-containing flue gas, limiting their engineering prospects. Physical adsorption is suitable for medium-to-high concentration CO₂ sources like converter gas. Furthermore, the technical characteristics of multiple utilization and storage paths such as steel slag mineralization, chemical conversion, and geological storage, were discussed. Steel slag mineralization offers dual benefits of solid waste disposal and carbon emission reduction, achieving a CO₂ storage capacity of 338 g per kilogram under optimal conditions, though accounting for less than 2% of total enterprise emissions, serving as a complementary approach rather than a standalone solution. In response to major challenges in the current demonstration phase, including high capture energy consumption, difficult process coupling, and insufficient full-chain integration experience, phased development paths and policy recommendations were proposed. These follow a "demonstration breakthrough-cluster development-commercial promotion" strategy and are considered from the perspectives of technology.