As can be seen from the Figure above, China has the highest and Mexico has the lowest total steel industry CO2 intensity. The total CO2 intensity of the Chinese steel industry is almost twice that of the Mexican steel industry. Two main reasons for low total CO2 intensity in Mexico’s steel industry are: a) Mexico has the largest share of EAF steel production among the four countries studied (69% in 2010), and b) Mexico’s steel industry consumes a larger share of natural gas compared to that in other countries studied. This results in a lower average emissions factor for fuels in Mexico. Another interesting point to note is that the total CO2 intensity of the German steel industry is 2% lower than that of the U.S. which is remarkable given that, in 2010, Germany had a lower share of EAF steel production (30% of total production) than the U.S. (61% of total production). However, it should be noted that the U.S. steel industry would have had lower CO2 intensity if we had not adjusted for net import of intermediary products to the steel industry, but that would have not been an accurate comparison.
Our analysis also showed that the CO2 intensity of BF/BOF steel production alone in the U.S. is significantly higher than that in other three countries. This could be because of various reasons such as older BF/BOF plants and lower penetration of some major energy efficiency technologies such as coke dry quenching (CDQ) and top-pressure recovery turbine (TRT) in blast furnaces, etc.
Some of the key factors influencing the CO2 intensities of the steel industry are: share of EAF from total steel production, the age of steel manufacturing facilities in each country, the level of penetration of energy-efficient technologies, the scale of production equipment, the fuel shares in the iron and steel industry, the steel product mix in each country, the CO2 emissions factor of electricity grid, etc.
Figure below shows the Top 10 countries from which U.S. imported steel in 2014.