Analysis of Environmental Burden of Steel Making Process by the Use of I/O Table

Abstract

Recycle of steel is expected to conserve natural resources, such as ores, and reduce environmental burden which accompanies steel production. However, the difference of environmental burden caused by blast furnace process and electric furnace process, which are used for steel recycling, is not quantitatively clear. In this study, we combine monetary data from I/O table and quantitative data from steel statistics, and estimate total CO₂ emission from each steel making process. According to the result, total CO₂ emission is 458kgC/t for BF process and 136kgC/t for EF process. We also evaluate the change of CO₂ emission from EF process in the case where more pig iron is added to EF process in order to lower the concentration of impurities. The result shows that the difference in CO₂ emission between both methods disappears when pig iron input exceeds 75% of the total charge of iron materials to EF process.