CO2 Emission of CO2 Injection into Blast Furnace

• Published in: Transactions of the Indian Institute of Metals Vol. 75; no. 5; pp. 1233 - 1244
• Main Authors: Jiang, Juanjuan, Dong, Kai, Zhu, Rong, Liu, Runzao
• Format: Journal Article
• Language: English
• Published: New Delhi Springer India 01.05.2022
• Subjects: Chemistry and Materials Science; Corrosion and Coatings; Materials Science; Metallic Materials; Original Article; Tribology; emission; Blast furnace; High-quality top gas; CO; Mathematical model
• ISSN: 0972-2815; 0975-1645
• DOI: 10.1007/s12666-021-02467-4

As an energy-intensive industry, the iron and steel industry has been facing the challenges associated with reducing CO 2 emissions. Therefore, metallurgical workers have been examining whether the steel industry can absorb some of the CO 2 emissions. At high temperatures, CO 2 is capable of oxidizing, which can lead to reactions with the carbon in the tuyeres raceway of the blast furnace to generate twice the volume of CO, improving the degree of indirect reduction and increasing the CO concentration in the top gas. In this study, metallurgical thermodynamics is used as the basis for constructing mathematical models of the mass and energy balance of a blast furnace and of the heat balance of a hot blast stove. Based on these models, the CO 2 emission of CO 2 injection into blast furnace is analyzed using the blast furnace CO 2 emission model. Because of the endothermic reaction between CO 2 and carbon, thermal compensation for the increases in the fuel ratio and oxygen enrichment is required. As the CO 2 enrichment rate increases, the input of CO 2 emission increases. However, as the CO concentration in the top gas increases and the top gas required by the hot blast stove decreases, the CO 2 emission reduction at the output increases. When the CO 2 enrichment limit is reached, the CO 2 emission at the input increases by 530.97 kg/(tHM), the CO 2 emission reduction at the output increases by 544.65 kg/(tHM), and the net CO 2 emission decreases by 13.68 kg/(tHM). The high-quality top gas can replace a portion of the role of gas producers and reduce the CO 2 emission of gas producers by 38.84 kg/(tHM). It can also prevent too much low-quality top gas from being released.