Blast Furnace Gas Utilization with Calcium-Assisted Steel Mill Off-Gas Hydrogen Production (CASOH) Technology: Technical Evaluation

In pursuit of decarbonizing the iron and steel industry through the utilization of blast furnace gas (BFG), this study investigates the technical feasibility of a Ca-Cu looping technology known as calcium-assisted steel mill off-gas hydrogen production (CASOH). The process is modeled and analyzed us...

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Detalles Bibliográficos
Autores: Khallaghi, Navid, Zapata-Boada, Santiago, Díaz Gutiérrez, Miriam, Wright, Andrew David, Fernández García, José Ramón, Abanades García, Juan Carlos, Spallina, Vincenzo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/399100
Acceso en línea:http://hdl.handle.net/10261/399100
https://api.elsevier.com/content/abstract/scopus_id/105010217821
Access Level:acceso abierto
Palabra clave:http://metadata.un.org/sdg/7
http://metadata.un.org/sdg/9
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Descripción
Sumario:In pursuit of decarbonizing the iron and steel industry through the utilization of blast furnace gas (BFG), this study investigates the technical feasibility of a Ca-Cu looping technology known as calcium-assisted steel mill off-gas hydrogen production (CASOH). The process is modeled and analyzed using Aspen Plus software. The key technical performances of two versions of CASOH were evaluated and compared with more traditional solvent-based technology for the precombustion decarbonization of BFG using methyl diethanolamine (MDEA). The first case (base case, CASOH-B) uses part of the BFG to regenerate the sorbent; therefore, it concentrates CO<inf>2</inf> up to 54%. In the second case (enhanced, CASOH-E), low-pressure steam is used for the calcination reaction. In the case of CASOH-B, the integration with a CO<inf>2</inf> purification unit outperforms the other configurations regarding the CO<inf>2</inf> capture efficiency, with values of up to 97% compared to 91% for CASOH-E and 83% for MDEA. However, CASOH-E demonstrated a significantly higher thermal output (224.5 MW<inf>LHV</inf> vs 77.6 MW<inf>LHV</inf> for CASOH-B), resulting in better cold gas efficiency and lower specific CO<inf>2</inf> emissions (76% and 29.8 kg<inf>CO<inf>2</inf></inf>/GJ<inf>LHV</inf> for CASOH-E compared to 26.3% and 105.7 kg<inf>CO<inf>2</inf></inf>/GJ<inf>LHV</inf> for CASOH-B). Various scenarios were analyzed to meet the heat and power requirements of the process. When relying on an external energy source such as natural gas, biogas, or photovoltaic panels, the solvent-based case outperforms the CASOH configurations with a specific energy consumption per CO<inf>2</inf> avoided (SPECCA) of 0.5-0.7 MJ<inf>LHV</inf>/kg<inf>CO<inf>2</inf></inf>, compared to 1.1-3.3 MJ<inf>LHV</inf>/kg<inf>CO<inf>2</inf></inf> for CASOH configurations. However, if the hydrogen-rich stream produced in CASOH-E is used to meet energy demands, then CASOH-E becomes the most favorable option. These findings emphasize the importance of operational parameters in optimizing BFG decarbonization strategies by balancing thermal output, efficiency, and emissions capture.