Life Cycle Assessment of Steel Production and Its Environmental Impacts

Despite its significant impact on the global economy, the iron and steel industry is also the largest consumer of energy and leaves behind a significant environmental footprint. Iran is also one of the top 10 steel producing countries, with more than 77% of its steel being produced in electric arc furnaces (EAFs). Therefore, a proper environmental assessment should be done to minimize the negative effects on the environment. The purpose of this study was to evaluate the life cycle of steel production using EAF method in Iran. This study identifies the major processes and inputs that affect the environmental impact of steel production and proposes effective methods to prevent pollution.

In this study, SimaPro software with ecoinvent database and IMPACT 2002+ evaluation method were used. Life cycle inventory data were obtained from the average performance of factories in one year and the functional unit was considered to be one ton of rolled steel (coil).

Among different categories of environmental impacts, non-renewable energy, global warming, and inhalation of mineral particles had the most significant threat, respectively, so that these three categories included 86.5% of the total environmental impact. Among several processes, the greatest effects were related to EAFs (35%), followed by sponge iron production (28.9%) and pellet production (17.1%) in second and third places, respectively. The highest environmental impacts of input materials included electricity (33.8%) and gas consumption (25.8%), respectively.

Despite significant advances in iron and steel industries in recent decades, they still have high energy consumption and carbon dioxide emissions. Conducting a life cycle assessment allows steel producers to identify the most polluting processes in order to make the necessary plans to improve them.