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.