Static Thermochemical Model of MIDREX: Genetic Algorithm Validation and Green Ironmaking with Hydrogen and Coke Oven Gas Injection

Abstract

This work presents the development and validation of a static thermochemical model for predicting process parameters in the MIDREX shaft furnace, a method used for producing direct reduced iron from lump ore and pellets. Industrial plant data is used to validate the model. Furthermore, the model is utilized to analyze the process based on different parameters. Genetic algorithm (GA) is used to estimate the critical parameters of the process (like reaction factors and extent of reactions) and validate the model with industrial data. Further investigations are conducted to assess the possibility of replacing the reformer gas (bustle gas) with hydrogen and coke oven gas (COG) to make the process greener and almost free from carbon emissions, using a systematic approach of overall heat balance, using already developed coupled thermodynamics and kinetics-based model, and further using those data to estimate the reaction factors and extent of reactions using GA to be used in the static model. The results demonstrate the feasibility of replacing hydrogen and COG without much adverse effect on the process outcomes; however, this results in better metallization and reduced carbon footprint of the process effectively.