A NUMERICAL STUDY OF SCENARIOS FOR THE SUBSTITUTION OF PULVERIZED COAL INJECTION BY BLAST FURNACE GAS ENRICHED BY HYDROGEN AND OXYGEN Jose Adilson De Castro1; Giulio Antunes De Medeiros2; Marcos De Campos3; Leonardo Martins Da Silva4; 1UFF - FEDERAL FLUMINENSE UNIVERSITY, Volta Redonda, Brazil; 2UFF-PROGRAMA DE POS GRADUAçãO EM ENGENHARIA METALURGICA, Volta Redonda, Brazil; 3UFF - FEDERAL FLUMINENSE U., Volta Redonda, Brazil; 4UNIVERSIDADE FEDERAL FLUMINENSE, Volta Redonda, Brazil; PAPER: 69/Iron/Regular (Oral) OS SCHEDULED: 16:20/Wed. 29 Nov. 2023/Dreams 2 ABSTRACT: A numerical simulation procedure is proposed for analyzing the partial replacement of pulverized coal injection by hydrogen, oxygen, and blast furnace gas (BFG) injections mixed with pulverized coal (PCI) within the tuyeres of large blast furnaces. The massive use of hydrogen-rich gas is highly attractive to the steelmaking blast furnace in the context of carbon net-zero hot metal production. Likewise, this new approach allows for increasing productivity and decreasing the specific emissions of carbon dioxide toward a net-zero carbon ironmaking technology. Nevertheless, pulverized coal injection gas mixture is a complex technology, in addition to the impact on chemical reactions and energy exchange, the internal temperature and gas flow pattern can also change drastically. With a view to assessing the state of the furnace in this complex operation, a comprehensive mathematical model using the multiphase theory was developed. The model simultaneously handles bulk solids (sinter, small coke, pellets, granular coke, and iron ore), gas, liquid metal and slag, and coal powder phases. The associated conservation equations are formulated for momentum, mass, chemical species, and energy while being discretized and solved using finite volume techniques. The numerical model was validated against the reference operating conditions using 220 kilograms per ton of pig iron (kg/tHM) of pulverized coal. Therefore, the combined injection of different concentrations of fuel hydrogen, blast furnace gas, and oxygen was simulated for replacing 40, 60 and 80 kg/tHM of coal injection. Theoretical analysis showed that the best scenario with stable operation conditions could be achieved with a productivity increase of 20% corresponding to a CO2 reduction of 15% and 60 kg/tHM of PCI replacement References: [1] Castro, J.A.; Takano, C.; Yagi, J. A theoretical study using the multiphase numerical simulation technique for effective use of H2 as blast furnaces fuel. J. Mater Res Technol., 2017, 6, 258-270. [2] Adilson de Castro, J.; Medeiros, G.A.d.; Oliveira, E.M.d.; de Campos, M.F.; Nogami, H. The Mini Blast Furnace Process: An Efficient Reactor for Green Pig Iron Production Using Charcoal and Hydrogen-Rich Gas: A Study of Cases. Metals 2020, 10, 1501. https://doi.org/10.3390/met10111501 [3] Castro, J.A. A Multi-Dimensional Transient Mathematical Model of Blast Furnace Based on Multi-Fluid Model. Doctor Thesis, Ph.D.-Tohoku University, Sendai, Japan, 2001. [4] Castro, J.A.; Araujo G.M.; Mota I.O.; Sasaki Y.; Yagi J. Analysis of the combined injection of pulverized coal and charcoal into large blast furnaces. J Mater Res Technol., 2013, 2, 308-314. |