Mathematical Modeling of the Energy Consumption and Carbon Emission for the Oxygen Blast Furnace with Top Gas Recycling

Abstract

The ironmaking process is the most significant source of CO 2 emission in the iron and steel industry, which generates large quantities of greenhouse gases. Recently, oxygen blast and top gas recycling have been applied to the blast furnace to improve the energy efficiency and reduce the pollution from the ironmaking process. However, as a new ironmaking technology, the oxygen blast furnace with top gas recycling (TGR-OBF) is still under development. This paper focuses on the investigation of the energy consumption and carbon emission for the TGR-OBF process by modeling the stack, the bosh, the combustion zone, and the gas recycling system. Effects of the key parameters in the TGR-OBF process on the carbon consumption of reactions and the energy consumption of the system are investigated by orthogonal experiments. Our results indicate that the TGR-OBF process has the advantages of reducing energy consumption and CO 2 emission. The low temperature and high reducing environment in the new furnace is favorable to lower the coke gasification and increase the reaction rate of iron oxide. The recycling of the top gas can significantly reduce CO 2 emission, and the main advantage comes when the stripped CO 2 is stored.

Vertical Section Observation of the Solid Flow in a Blast Furnace with a Cutting Method

“…Nevertheless, the vertical sections of solid flow under different burden layer conditions, as shown in Figure 4, all indicate that the plug flow is the main solid flow pattern in the upper and middle zones during burden descending, whereas a slight convergence flow and a deadman zone form at the lower part of the bosh. Therefore, when analyzing the heat-mass transfer and metallurgical reactions in the BF, the plug flow should be used to model the solid phase, which agrees well with the literature [29]. The results can provide important information for building the one-dimensional model and the two-dimensional model used to simulate the movement and reaction of coke/ore in BFs.…”

Evolution of Blast Furnace Process toward Reductant Flexibility and Carbon Dioxide Mitigation in Steel Works

“…Model structure of top gas recycling based on oxygen blast furnace process. 41) energy balance, as shown in Fig. 20.…”

“…[34][35][36] Following the development of that process, similar processes have also been actively studied. [37][38][39][40][41][42] Top gas recycling is considered to represent a further evolution of the previous reducing gas injection process.…”

“…These analyses were recently carried out by the following authors. Figure 16 shows the top gas recycling process model developed by Jin et al, 41) including a one-dimensional model of heat transfer and the reactions in the stack and bosh zone of the blast furnace, an equilibrium model for combustion at the main tuyere level and a mass and energy balance model for the separation and preheating of the top gas. They focused on the carbon consumption in the blast furnace region and considered the energy required for blast power, oxygen production and CO 2 separation in the estimation of CO 2 emissions.…”

“…These tendencies agree with the results of Jin and Sahu. 41,42) However, it should be noted that the energy supply to downstream processes decreases as a result of intensified top gas recycling. This calculation does not include the energy required for CO 2 sequestration because a large-scale CO 2 sequestration process suitable for the ironmaking process is still in the developmental stage.…”