THE THERMOCHEMISTRY EVALUATION OF DIRECT REDUCTION REACTOR

• Main Author: INDI BARAMUNI (NIM. 23003013), LUH
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/13617
• Institution: Institut Teknologi Bandung

</i><b>Abstract: <i></b><p align="justify"> PT Krakatau Steel is the only integrated steel manufacturer in Indonesia, with an annual production of 2.4 million ton. The heart of this industry lies in the Direct Reduction (DR) reactor, which converts iron ore into sponge iron and iron carbide. The DR reactor is a moving bed reactor, in which iron ore moves downward by gravitation and reacts with reducing gas (mostly hydrogen) injected in the top half, or reducing zone, of the reactor. After reduction, the sponge iron is cooled by injecting cooling gas (mostly methane) at the bottom half of reactor, which is the cooling zone. Between the reduction and cooling zone lies the isobaric zone that prevents the mixing of reducing gas and cooling gas. In practice, about 5% of the cooling gas leak through the isobaric zone and mix with the reducing gas.<p align="justify"> This research is aimed at evaluating the thermochemistry of the three distinct zones of the DR reactor. The equilibrium composition of gas-solid reactants is simulated for every zone within the temperature range of the given zone by using FACTSage 5.2 software that was developed by Ecole Polytechnique de Montreal, Canada. Data and compositions which are available from PT Krakatau Steel are used as boundary conditions. Additional data in certain areas are provided by simulation using shrinking core reaction rate theory and/or mass and energy balances.<p align="justify"> The simulation results indicate that the reduction zone involves several gas phase and gas-solid reactions, including iron ore reduction by H₂, CO and CH₄, methane reformation into CO and H₂, and water gas shift reaction. In the isobaric zone, a fraction of the metallic iron is carburized into Fe₃C. In the cooling zone, the thermodynamically feasible reaction is the deposition of carbon soot resulting from methane carbonization.</p>