Muti-objective optimization on energy consumption, CO₂ emission and production cost for iron and steel industry

Due to high material density, high energy consumption density and CO₂ emission density, it is not only difficult but significant to clarify the relationship between energy consumption, the CO₂ emission and the production cost in different conditions. However, the previous researches rarely refer how to balance the energy consumption, the CO₂ emission and the production cost after the fluctuation of material, energy and carbon price as well as what will happen to them if production structure changes. Therefore, based on the conservation law of mass and energy, to study iron and steel manufacturing process (ISMP), this paper, taking carbon price into consideration, establishes a muti-optimization model of energy consumption, CO₂ emission and cost. After optimization with different objectives, the production cost per tonne of crude steel is reduced by 192.03 CNY (7.71%), the CO₂ emission per tonne of crude steel is reduced by 224.22 kg (13.37%), and the energy consumption per tonne of steel is reduced by 51.20 kgce (9.10%). Moreover, based on the optimization results under different objectives, it is ironmaking process (coal ratio and ore ratio) and steelmaking process (amount of scrap steel) that has more impact on three above as well as ore blending and coal blending have a great influence on production cost but little effect on energy consumption and CO₂ emission.