Proceedings of the Seminar on Energy, Utilities and Industrial Gases


ISSN 2594-3626

Title

TOWARDS SUSTAINABLE STEELMAKING – EFFICIENT ENERGETIC UTILIZATION OF BLAST FURNACE GAS VIA MOLTEN CARBONATE FUEL CELLS

TOWARDS SUSTAINABLE STEELMAKING – EFFICIENT ENERGETIC UTILIZATION OF BLAST FURNACE GAS VIA MOLTEN CARBONATE FUEL CELLS

DOI

10.5151/2594-3626-32057

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Abstract

Pressurized molten carbonate fuel cell (MCFC) hybrid system can be seen as an innovative and promising technology for efficient conversion of blast furnace gas into electricity. In this context, the present study provides a steady-state model for MCFC system based on anode and cathode gas recirculation concept, with blast furnace gas being used as a fuel. The developed code allows calculating, in an iterative and integrated way, heat and mass balance for the whole system, by modeling each module, namely, reformer, MCFC stack, afterburner, mixers, spliters, gas and steam turbines, and air compressor. Adiabatic reformer was modeled according to entropy maximization, allowing a more straightforward integration with MCFC anode. Firstly, the model is validated for MCFC architecture operating on natural gas, and satisfactory agreement was found, when compared with theoretical data available from recent literature; in this case, the proposed architecture yields an electrical efficiency of 67%. Then, the simulation is carried out for MCFC system operating on blast furnace gas, considering an average gas composition (5%H2, 1%CH4, 18%CO2, 23%CO, 53%N2) from a charcoal blast furnace of a non-integrated producer with capacity of 200 tonnes of pig iron per day. The whole process flowsheet diagram (PFD) is provided for a designed 3.5 MW AC MCFC system, yielding 60.6% net AC electrical efficiency. Such a high efficiency is achieved for pressurized system (7.5 atm), single cell voltage of 0.77V, at current density of 1370 A/m2. This high value for electrical efficiency could boost distributed generation from blast furnace gas. In this way, we provide an estimate of power production for several non-integrated pig iron producers located in Minas Gerais State.

 

Pressurized molten carbonate fuel cell (MCFC) hybrid system can be seen as an innovative and promising technology for efficient conversion of blast furnace gas into electricity. In this context, the present study provides a steady-state model for MCFC system based on anode and cathode gas recirculation concept, with blast furnace gas being used as a fuel. The developed code allows calculating, in an iterative and integrated way, heat and mass balance for the whole system, by modeling each module, namely, reformer, MCFC stack, afterburner, mixers, spliters, gas and steam turbines, and air compressor. Adiabatic reformer was modeled according to entropy maximization, allowing a more straightforward integration with MCFC anode. Firstly, the model is validated for MCFC architecture operating on natural gas, and satisfactory agreement was found, when compared with theoretical data available from recent literature; in this case, the proposed architecture yields an electrical efficiency of 67%. Then, the simulation is carried out for MCFC system operating on blast furnace gas, considering an average gas composition (5%H2, 1%CH4, 18%CO2, 23%CO, 53%N2) from a charcoal blast furnace of a non-integrated producer with capacity of 200 tonnes of pig iron per day. The whole process flowsheet diagram (PFD) is provided for a designed 3.5 MW AC MCFC system, yielding 60.6% net AC electrical efficiency. Such a high efficiency is achieved for pressurized system (7.5 atm), single cell voltage of 0.77V, at current density of 1370 A/m2. This high value for electrical efficiency could boost distributed generation from blast furnace gas. In this way, we provide an estimate of power production for several non-integrated pig iron producers located in Minas Gerais State.

Keywords

Molten Carbonate Fuel Cell; Modelling; Blast Furnace Gas; Energetic Efficiency

Molten Carbonate Fuel Cell; Modelling; Blast Furnace Gas; Energetic Efficiency

How to refer

Silva, Aline Lima da; Heck, Nestor Cezar. TOWARDS SUSTAINABLE STEELMAKING – EFFICIENT ENERGETIC UTILIZATION OF BLAST FURNACE GAS VIA MOLTEN CARBONATE FUEL CELLS , p. 133-147. In: 39° Seminário de Balanços Energéticos Globais e Utilidades, São Paulo, 2018.
ISSN: 2594-3626 , DOI 10.5151/2594-3626-32057