Analysis of CO2 emission and energy consumption in CCUS for steel-chemical joint production

Iron, steel, and coal chemical industries are typically large-scale CO₂-emitting industries. Therefore, identifying a suitable steel-chemical joint production (SCJP) process is crucial for reducing joint carbon emissions. This study examines China's first basic oxygen furnace gas (BOFG), CO purification (CP), CO₂ capture (CC), and CO₂ utilization for long-process smelting as case studies to compare and analyze the differences between conventional long-process smelting and the SCJP approach in terms of CO₂ emissions, energy consumption, and economic benefits. By applying the life cycle assessment (LCA) theory and the gray-box model, CO₂ utilization in blast furnaces (BF) and basic oxygen furnaces (BOF) was determined to be conducive to the reduction of carbon emissions during the entire process. However, the SCJP process increases its energy consumption due to the addition of CP and CC processes. Compared to the conventional long-process smelting, using the SCJP process, the reduction of CO₂ emission per ton of crude steel is 25.4 kg, the CO₂ fixed through a product CO and CO₂-based product is 76.2 kg, the energy consumption is increased by 9.78 kg of coal equivalent, and the final smelting cost per ton of steel is lowered by 12.30 RMB.