Título

THE EFFECTIVE USE OF HYDROGEN GAS AS BLAST FURNACES FUEL: A THEORETICAL STUDY USING A COMPREHENSIVE MULTIPHASE NUMERICAL SIMULATION TECHNIQUE

THE EFFECTIVE USE OF HYDROGEN GAS AS BLAST FURNACES FUEL: A THEORETICAL STUDY USING A COMPREHENSIVE MULTIPHASE NUMERICAL SIMULATION TECHNIQUE

Autoria

Castro, Jose Adilson de; Medeiros, Giulio Antunes de; Oliveira, Elizabeth Mendes de; Silva, Leonardo Martins da

DOI

10.5151/5463-5463-35063

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Resumo

We present a numerical simulation procedure for analyzing hydrogen, oxygen and carbon dioxide gases injections mixed with pulverized coals within the tuyeres of blast furnaces. Effective use of H2 rich gas is highly attractive into the steelmaking blast furnace, considering the possibility of increasing the productivity and decreasing the specific emissions of carbon dioxide becoming the process less intensive in carbon utilization. However, the mixed gas and coal injection is a complex technology since significant changes on the inner temperature and gas flow patterns are expected, beyond to their effects on the chemical reactions and heat exchanges. Focusing on the evaluation of inner furnace status under such complex operation a comprehensive mathematical model has been developed using the multi interaction multiple phase theory. The BF, considered as a multiphase reactor, treats the lump solids (sinter, small coke, pellets, granular coke and iron ores), gas, liquids metal and slag and pulverized coal phases. The governing conservation equations are formulated for momentum, mass, chemical species and energy and simultaneously discretized using the numerical method of finite volumes. We verified the model with a reference operational condition using pulverized coal of 215 kilogram per ton of hot metal (kg.thm-1). Thus, combined injections of varying concentrations of gaseous fuels with H2, O2 and CO2 are simulated with 220 kg.thm-1 and 250 kg.thm-1 coals injection. Theoretical analysis showed that stable operations conditions could be achieved with productivity increase of around 50%. Finally, we demonstrated that the net carbon utilization per ton of hot metal decreased up to 25%.

 

We present a numerical simulation procedure for analyzing hydrogen, oxygen and carbon dioxide gases injections mixed with pulverized coals within the tuyeres of blast furnaces. Effective use of H2 rich gas is highly attractive into the steelmaking blast furnace, considering the possibility of increasing the productivity and decreasing the specific emissions of carbon dioxide becoming the process less intensive in carbon utilization. However, the mixed gas and coal injection is a complex technology since significant changes on the inner temperature and gas flow patterns are expected, beyond to their effects on the chemical reactions and heat exchanges. Focusing on the evaluation of inner furnace status under such complex operation a comprehensive mathematical model has been developed using the multi interaction multiple phase theory. The BF, considered as a multiphase reactor, treats the lump solids (sinter, small coke, pellets, granular coke and iron ores), gas, liquids metal and slag and pulverized coal phases. The governing conservation equations are formulated for momentum, mass, chemical species and energy and simultaneously discretized using the numerical method of finite volumes. We verified the model with a reference operational condition using pulverized coal of 215 kilogram per ton of hot metal (kg.thm-1). Thus, combined injections of varying concentrations of gaseous fuels with H2, O2 and CO2 are simulated with 220 kg.thm-1 and 250 kg.thm-1 coals injection. Theoretical analysis showed that stable operations conditions could be achieved with productivity increase of around 50%. Finally, we demonstrated that the net carbon utilization per ton of hot metal decreased up to 25%.

Palavras-chave

Hydrogen; Tuyere injection; CO2 emission; Mathematical modeling; Pulverized coal

Hydrogen; Tuyere injection; CO2 emission; Mathematical modeling; Pulverized coal