Title: Exergo-economic assessment of an improved combined flash-binary geothermal cycle for hydrogen and desalinated water production

Authors: Mohammad Ali Sabbaghi

Addresses: Department of Mechanical Engineering, Yazd University, Yazd, Iran

Abstract: This study proposes a combined flash-binary cycle to generate power, hydrogen, and desalinated water from geothermal wells, employing a supercritical CO₂ (SCO₂) cycle, which is improved by a thermoelectric generator (TEG). The proposed cycle underwent analysis from energy, exergy, and economic perspectives using real data from existing geothermal wells. Results indicate energy and exergy efficiencies of 14.71% and 38.59%, respectively, with the capability of producing 0.003698 kg/s of hydrogen and 133 kg/s of desalinated water. Thermo-economic analysis reveals production costs of $3.45/kg for hydrogen and 39.7 cents/m³ for desalinated water, outperforming previous studies.

Keywords: geothermal; supercritical CO₂ cycle; hydrogen; desalinated water; thermo-economic; thermoelectric generator.

DOI: 10.1504/IJEX.2025.146796

International Journal of Exergy, 2025 Vol.47 No.2, pp.91 - 103

Received: 27 Aug 2024
Accepted: 23 Dec 2024
Published online: 18 Jun 2025 *

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