Feasibility Study on Blast Furnace Ironmaking System Integrated with Methanol Synthesis for Reduction of Carbon Dioxide Emission and Effective Use of Exergy

Abstract

Partial replacement of coke by natural gas and production of methanol from the off gas will result in the integrated blast furnace ironmaking system with methanol synthesis. According to the requirement of reduction of CO₂ emission and energy savings, the feasibility study of the integrated system was conducted. Operating data of the new system was calculated by a mathematical model based on the heat and mass balances. The effect of operating conditions, such as replacement amount of coke and conversion factor to methanol, on the total emisson of greenhouse effect gas (GEG) and on the exergy loss was examined. The exergy loss and the GEG emission decreased with increase in the replacement amount of coke by natural gas and the conversion factor. In the operation case that has 300 kg-coke/thm and 219 Nm³-natural gas/thm in fuel ratio and 2.3% in conversion factor, the total amount of GEG decreased from 542 to 454 kg/thm and the sum of exergy loss also decreased from 9.0 to 8.2 GJ/thm.