Comparison of carbon dioxide emissions intensity of steel production in China, Germany, Mexico, and the United States

• Development of a method for comparison of CO2 intensity of steel industry.
• Boundary definitions, conversion factors, and industry structure are considered.
• CO2 intensity of steel industry in China, Germany, Mexico, and the U.S. in 2010.
• Four scenarios were developed to assess the effect of different factors.

Production of iron and steel is an energy-intensive manufacturing process. The goal of this study was to develop a methodology for accurately and more fairly comparing the energy-related carbon dioxide (CO2) emissions intensity of steel production in different countries and to demonstrate the application of this methodology in an analysis of the steel industry in China, Germany, Mexico, and the U.S. Our methodology addresses the industry’s boundary definition, conversion factors, and industry structure. The results of our analysis show that, for the entire iron and steel production process, the base-case (2010) CO2 emissions intensity was 2148 kg CO2/tonne crude steel in China, 1708 kg CO2/tonne crude steel in Germany, 1080 kg CO2/tonne crude steel in Mexico, and 1736 kg CO2/tonne crude steel in the U.S. One of the main reasons that Mexico has the lowest CO2 emissions intensity is Mexico’s large share of steel production using electric arc furnaces (EAFs) (69.4%). EAF steel production has lower CO2 emissions intensity than production using blast furnaces/basic oxygen furnaces. China, by contrast, has the smallest share of EAF production among the four countries—9.8% in the base-case year 2010. In one scenario, we applied the Chinese share of EAF production to the other three case-study countries; the result was an increase in CO2 emissions intensity of steel production of 19% (2036 kg CO2/tonne crude steel) in Germany, 92% (2074 kgCO2/tonne crude steel) in Mexico, and 56% (2703 kg CO2/tonne crude steel) in the U.S. compared to these countries’ base-case analyses. In another scenario, we applied the Chinese national average grid electricity CO2 emissions factor from 2010, which is the highest emissions factor among the four countries, to the other three countries. In that scenario, the CO2 emissions intensity of steel production increased by 5% in Germany, 11% in Mexico, and 10% in the U.S.