Off-Gas System Scale-Up of HIsarna Iron-Making Process: A CFD-Based Approach

Abstract

For all industrial applications, predicting system characteristics and behavior plays a vital role before constructing costly and complex multi-physic systems. Correct and reliable predictions become even more important once the aim is to go from small- to large-scale processes to establish an industrial demonstrations. In this study, a CFD-based scale-up of HIsarna off-gas system based on the Eulerian–Lagrangian approach is investigated and detailed step in scale-up procedure is discussed. A three-dimensional CFD model is developed and validated based on the available pilot scale data and used to design and scale up the post-combustion chamber (also known as reflux chamber). Detailed kinetics for volumetric and gas–solid reactions are incorporated in validated CFD model with a special attention to the wall boundary condition and modeling. The effect of reflux chamber geometry, oxygen injection ports, oxygen injection flowrate, isolation wall thickness, and inlet flue gas composition on different system characteristics such as heat loss through the wall, CO–H2–carbon mixture conversion, flue gas, and wall temperature are investigated. The aim of the scaled up geometry, like pilot scale, is to achieve full combustion of unwanted species inside the reflux chamber to assure zero emissions from the off-gas system. Compared to the pilot scale, the scaled up reflux chamber is capable of handling and removing higher amount of unwanted species coming from the main reactor and therefore lower CO–H2 and carbon particle emissions, mainly due to a larger size which provides larger volume and residence time for volumetric and gas–solid reaction to proceed.

Mathematical Modeling for the Process of Smelting Reduction Ironmaking Integrated with Hydrogen-Rich Coal Gasification

“…HIsmelt has been in development for over 40 years and successfully commercialized. Based on the successful experience of the HIsmelt process, Hisarna has been proposed by combining the cyclone furnace of CCF (Cyclone Converter Furnace) technology and the SRV of Hismelt technology [18][19][20]. The flash ironmaking technology utilizes a Flash Reduction Shaft (FRS) and a SRV, but unlike Hismelt and Hisarna, it uses H 2 or natural gas instead of coal as the reducing agent and fuel [21][22][23].…”