Jose Adilson de Castro

Abstract:

The reduction of pellets and lump ores in the shaft furnace process is widely used to produce direct reduced iron (DRI). The traditional process of DRI production uses a gas reforming system based on catalytic reactions and demands high amount of fossil source energy from natural gas. A new hydrogen-based process has been proposed. In this study, we propose to combine self-reducing characteristics with hydrogen technology with self-catalytic reactions to avoid the natural gas-based reforming step. We analyzed this new technology using an in-house computational code. The computational analysis is a numerical model based on transport equations of momentum, energy and chemical species for gas and solid phases to reproduce the inner phenomena in the direct reduction of the shaft furnace process for producing DRI. The model is used to investigate promising scenarios of hydrogen-based technology. Four cases were considered using partial replacement of the burden by bio-self-reducing agglomerates combining with hydrogen and oxygen injections on the bustle level. The inner temperature, pressure and phase composition distributions are discussed for the selected scenarios. The simulation results indicated that the efficiency of the process can be improved with the adequate choice of operational parameters and raw materials burden.

[1] Castro, JA, Takano, C., Yagi, J. A theoretical study using the multiphase numerical simulation technique for effective use of H2 as blast furnaces fuel. Journal of Materials Research and Technology, v.6(3), p.258-270, 2017.