Effect of multi-component gases on the behavior and mechanism of carbon deposition in hydrogen-rich blast furnaces. (15th January 2023)

• Record Type: Journal Article
• Authors: Jiao, Kexin; Feng, Guangxiang; Zhang, Jianliang; Wang, Cui; Zhang, Lei
• Is Part Of: Energy. Volume 263:Part A(2023)
• Publication Date: 2023-01-15
• Subjects: Hydrogen-rich blast furnace -- Carbon deposition -- Carbon deposition rate -- Filamentous carbon -- Formation mechanism; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2022.125518
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: Hydrogen-rich blast furnace is considered an advanced technology in the iron and steel industry for reducing carbon emissions at the source. The CO utilization is instead reduced due to the severe carbon deposition behavior after hydrogen enrichment. This paper quantitatively investigated the effect of CO–H2 –H2 O–N2 multi-component on carbon deposition behavior, and a formation mechanism of deposited carbon was proposed finally. The results revealed that the optimum temperature range for carbon deposition was about 470–900 °C, and the maximum rate of carbon deposition was reached at 550–700 °C. At 600 °C, the carbon deposition rate for 100%CO and 40%CO–60%N2 were 0.54 g/d and 0.13 g/d, respectively. The aggravating effect of H2 to carbon deposition was 5.2 times that of H2 O. Whereas the carbon deposition will be constrained in low CO and high H2 environment. The SEM showed that the morphology of the deposited carbon was filamentous, its formation mechanism on the iron surface is: (a) Adsorption of gases on the iron surface, (b) Formation of Fe3 C layer, (c) Deposition of graphite layer, (d) Decomposition of Fe3 C layer, (e) Formation of Fe3 C–Fe + C (diss.) catalytic particles, (f) Formation of filamentous carbon, (g) Carbon activity in metallic Fe-filamentous carbon. Highlights: The temperature range for carbon deposition is 470–900 °C based on TG experiment. Carbon deposition rate is quantified and greatly aggravated by H2 . Effect of temperature on carbon deposition is attenuated strongly by H2 . Effect of H2 and H2 O on the morphology of deposited carbon is the opposite. Structural parameters and formation mechanism of filamentous carbon is revealed.