Environmental impact evaluation of an iron and steel plant in China: Normalized data and direct/indirect contribution

Abstract

In 2018, 88% of the crude steel manufactured in China was produced by blast furnace - basic oxygen furnace (BF-BOF) route. This leads to high energy consumption and greenhouse gas emissions in China’s iron and steel industry. In this study, the life cycle assessment of environmental impact in an iron and steel plant was evaluated by using GaBi v.8.7 software. Eight assessment categories were evaluated to determine direct/indirect contribution, and the results of impact categories were further normalized for comparison among different unit processes. The results indicated that the BF alone contributed greatly to various environmental impact categories, or 73% Abiotic Depletion Potential (ADP), 54% Eutrophication Potential (EP), and 69% Global Warming Potential (GWP). Different scenario settings were established to reduce nonrenewable fuel consumption and corresponding environmental impacts. The scenario 2 (replacement of coke and anthracite in BF with charcoal) and scenario 3 (increasing electric arc furnace (EAF) route) were able to reduce total environmental impacts by 14% and 25%, respectively, as compared to the scenario 1 (existing conditions). The normalized results of each assessment category scores indicated that the main environmental impacts of production process were Human Toxicity Potential (33%), GWP (30%) and ADP (25%). The EAF route exhibits less environmental impact than BF-BOF route, especially in GWP, ADP, Cumulative Energy Demand and EP. In the future, steel making enterprises in China should be encouraged to shift their process from BF-BOF to EAF route as was done in developed countries.