A Numerical Study on the Operation of the H2 Shaft Furnace with Top Gas Recycling

Abstract

The breakthrough route involving a reduction shaft furnace operated with pure hydrogen gas (here called H 2-SF) and the electric arc furnace is widely accepted as one of the most viable future alternatives for industrial-scale production of primary steel with minor CO 2 emissions. It has been clarified that the largest portion of the total energy for the entire route is consumed by the H 2-SF operation, but this unit has not yet received much attention and should therefore be explored. For this, a mathematical model of a reduction shaft furnace is presented in this paper, where a set of simulations were also performed to shed more light on the operation of the H 2-SF equipped with a top gas recycling system. The results show that a high gas feed rate is required for guaranteeing a smooth H 2-SF operation due to the strong heat demand. An increase in the feed temperature of the gas or in furnace height can reduce the required gas feed. However, an excessive length may conversely result in an increase in the total energy consumption. The model and its results are expected to be helpful for gaining a better understanding of the complex processes in and constraints of the H 2-SF.

A Numerical Study on the Performance of the H2 Shaft Furnace with Dual-Row Top Gas Recycling

“…In earlier work by the authors [10], the model was validated by comparing its predictions with measured data from a small-scale syngas-based shaft furnace [17,18], showing a reasonable overall agreement. To further assess the accuracy of the model, industrial production data of a MIDREX shaft furnace (Gilmore plant) reported by Parisi and Laborde [19], and later by Shams and Moazeni [20], were used.…”

“…It can be further calculated that the top gas utilization degree (i.e., mole fraction of H 2 O in the gas mixture consisting of H 2 O and H 2 ) is roughly 0.27 under the operating conditions considered. The present authors [10] also developed a H 2 -SF model and predicted that the top gas utilization degree is generally lower than 0.25 for scenarios where pure H 2 is injected into the furnace and the target DRI metallization degree is (close to) 1.0. In a recent publication [11], the study was extended to a new top gas recycling (TGR) concept featuring dual-row injection as an alternative way of relaxing the strong constraints imposed by the need to supply a large portion of thermal energy to the process.…”

“…This is motivated by the fact that metals reflect microwaves and cannot be heated efficiently. In the following, only the key treatment and governing equations of the model are outlined: the reader is referred to Shao et al [10] for detailed information about it.…”

“…For the two-point boundary conditions that result from the nature of the countercurrent flows, the solution of the ODEs can be found by a shooting method. For detailed information about the numerical method, the reader is referred to Shao et al [10]. The total energy demand of the entire process is the sum of the energy demand of electrolysis, compression and heating.…”

Numerical simulation of the dolomite in-situ desulfurization in molten iron

“…flux additions, reagent injection, resulfurization, and reagent dispersion [15][16][17][18][19]. To forecast the desulfurization behavior in the ladle, several researchers [20][21][22] also suggested mathematical models including the thermodynamic processes and the computational fluid dynamics (CFD) model. To simulate the desulfurization process in the kambara reactor (KR), Wang et al [23] developed a three-dimensional transient coupling mathematical model utilizing the volume of fluid (VOF) and discrete phase model.…”