Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 57 5 2025 07 23 Thermoeconomic Analysis of a Polygeneration System for Flare Gas Recovery with Crude Oil Preheating Thermoeconomic Analysis of a Polygeneration System for Flare Gas Recovery with Crude Oil Preheating 633 662 5848 10.22060/mej.2025.24492.7875 FA Mostafa Mahboobi University of Kashan 0009-0002-6364-2636 Ghanbar Ali Sheikhzadeh Member of Faculty/University of Kashan 0000-0002-7874-9981 Abolfazl Fattahi University of Kashan Journal Article 2025 07 30 Flare gas, a byproduct of oil extraction, is usually burned without useful application, despite having a high potential for energy recovery. This study has designed and analyzed a polygeneration system for utilizing flare gas to simultaneously produce power, fresh water, hydrogen, and heat. The proposed system includes a supercritical carbon dioxide power cycle, a thermoelectric generator, crude oil preheating, a reverse osmosis desalination unit, and hydrogen production in a proton exchange membrane electrolyzer. Modeling was performed using Engineering Equation Solver software and evaluated through energy, exergy, and exergoeconomic analyses. The novelty of the study lies in presenting an integrated system that optimizes multi-product generation from flare gas to meet industrial and domestic demands. The basic design results indicate an energy efficiency and exergy efficiency of 83.24% and 23.56%, a net output power of 12.23 MW, and a thermal load capacity of 13.39 MW. Hydrogen production is 60.93 kg/day, fresh water production is 106.7 kg/s, and the total exergy product cost rate, total exergy destruction cost rate, and total investment cost are 2,982.96, 347.58, and 645.84 $/h, respectively, with a payback period of 1.72 years. Finally, the impact of key parameters on the system performance has been examined using sensitivity analysis. Flare gas, a byproduct of oil extraction, is usually burned without useful application, despite having a high potential for energy recovery. This study has designed and analyzed a polygeneration system for utilizing flare gas to simultaneously produce power, fresh water, hydrogen, and heat. The proposed system includes a supercritical carbon dioxide power cycle, a thermoelectric generator, crude oil preheating, a reverse osmosis desalination unit, and hydrogen production in a proton exchange membrane electrolyzer. Modeling was performed using Engineering Equation Solver software and evaluated through energy, exergy, and exergoeconomic analyses. The novelty of the study lies in presenting an integrated system that optimizes multi-product generation from flare gas to meet industrial and domestic demands. The basic design results indicate an energy efficiency and exergy efficiency of 83.24% and 23.56%, a net output power of 12.23 MW, and a thermal load capacity of 13.39 MW. Hydrogen production is 60.93 kg/day, fresh water production is 106.7 kg/s, and the total exergy product cost rate, total exergy destruction cost rate, and total investment cost are 2,982.96, 347.58, and 645.84 $/h, respectively, with a payback period of 1.72 years. Finally, the impact of key parameters on the system performance has been examined using sensitivity analysis.

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