Thermoeconomic optimization of a geothermal-assisted hybrid LNG and power generation system: Simulation, performance assessment, and sustainability insights

This study investigates the optimization and economic analysis of a geothermal-assisted hybrid natural gas liquefaction (LNG) and power generation system, integrating geothermal energy to enhance efficiency and sustainability. The system's performance is evaluated using Aspen Plus simulations a...

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Main Authors: Ceyhun Yilmaz, Muhammed Arslan, Nehir Tokgoz, Safiye Nur Ozdemir
Format: Article
Language:English
Published: Elsevier 2025-09-01
Series:Case Studies in Thermal Engineering
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Online Access:http://www.sciencedirect.com/science/article/pii/S2214157X25006860
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author Ceyhun Yilmaz
Muhammed Arslan
Nehir Tokgoz
Safiye Nur Ozdemir
author_facet Ceyhun Yilmaz
Muhammed Arslan
Nehir Tokgoz
Safiye Nur Ozdemir
author_sort Ceyhun Yilmaz
collection DOAJ
description This study investigates the optimization and economic analysis of a geothermal-assisted hybrid natural gas liquefaction (LNG) and power generation system, integrating geothermal energy to enhance efficiency and sustainability. The system's performance is evaluated using Aspen Plus simulations and numerical modeling, providing a comprehensive thermoeconomic assessment. Geothermal energy is utilized for two purposes: generating green electricity and reducing the energy demand for LNG production. Geothermal water, extracted at 130 °C and 100 kg/s, supplies heat to an absorption cooling system that precools natural gas to −45 °C before liquefaction. A geothermal power plant with 110 °C geothermal water generates 3000 kW of power, of which 1700 kW is utilized for the liquefaction process at 0.03 $/kWh. At the same time, excess electricity is managed through a power control unit. The system achieves an LNG production cost of 0.44 $/kg, with a liquefaction coefficient of performance (COP) of 0.74 and an exergy efficiency of 41.0 %. The idealized minimum work requirement is 460.5 kJ/kg, while practical evaluations indicate an actual work requirement of 1113 kJ/kg, highlighting actual operational constraints. The thermoeconomic assessment underscores the balance between technical efficiency and economic feasibility, demonstrating the potential of geothermal-assisted LNG for long-distance natural gas transportation. Integrating renewable geothermal energy enhances system efficiency and reduces operational costs, aligning with sustainable energy strategies. The model also aligns well with Engineering Equation Solver (EES) numerical simulations, presenting opportunities for further optimization through advanced modeling and artificial intelligence-based approaches. This study provides valuable insights for developing cost-effective and sustainable LNG technologies, offering a promising alternative for improving LNG production efficiency while leveraging renewable energy resources.
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spelling doaj-art-617b6dc3f7ef418083d4f0a0fed791172025-08-20T02:08:35ZengElsevierCase Studies in Thermal Engineering2214-157X2025-09-017310642610.1016/j.csite.2025.106426Thermoeconomic optimization of a geothermal-assisted hybrid LNG and power generation system: Simulation, performance assessment, and sustainability insightsCeyhun Yilmaz0Muhammed Arslan1Nehir Tokgoz2Safiye Nur Ozdemir3Department of Mechanical Engineering, Sakarya University, Turkey; Corresponding author.Afyon Kocatepe University, Motor Vehicles and Transportation Technologies, TurkeyDepartment of Mechanical Engineering, Sakarya University, TurkeyDepartment of Mechanical Engineering, Sakarya University, TurkeyThis study investigates the optimization and economic analysis of a geothermal-assisted hybrid natural gas liquefaction (LNG) and power generation system, integrating geothermal energy to enhance efficiency and sustainability. The system's performance is evaluated using Aspen Plus simulations and numerical modeling, providing a comprehensive thermoeconomic assessment. Geothermal energy is utilized for two purposes: generating green electricity and reducing the energy demand for LNG production. Geothermal water, extracted at 130 °C and 100 kg/s, supplies heat to an absorption cooling system that precools natural gas to −45 °C before liquefaction. A geothermal power plant with 110 °C geothermal water generates 3000 kW of power, of which 1700 kW is utilized for the liquefaction process at 0.03 $/kWh. At the same time, excess electricity is managed through a power control unit. The system achieves an LNG production cost of 0.44 $/kg, with a liquefaction coefficient of performance (COP) of 0.74 and an exergy efficiency of 41.0 %. The idealized minimum work requirement is 460.5 kJ/kg, while practical evaluations indicate an actual work requirement of 1113 kJ/kg, highlighting actual operational constraints. The thermoeconomic assessment underscores the balance between technical efficiency and economic feasibility, demonstrating the potential of geothermal-assisted LNG for long-distance natural gas transportation. Integrating renewable geothermal energy enhances system efficiency and reduces operational costs, aligning with sustainable energy strategies. The model also aligns well with Engineering Equation Solver (EES) numerical simulations, presenting opportunities for further optimization through advanced modeling and artificial intelligence-based approaches. This study provides valuable insights for developing cost-effective and sustainable LNG technologies, offering a promising alternative for improving LNG production efficiency while leveraging renewable energy resources.http://www.sciencedirect.com/science/article/pii/S2214157X25006860Geothermal energyNatural gas liquefactionThermodynamic analysisThermoeconomic analysis
spellingShingle Ceyhun Yilmaz
Muhammed Arslan
Nehir Tokgoz
Safiye Nur Ozdemir
Thermoeconomic optimization of a geothermal-assisted hybrid LNG and power generation system: Simulation, performance assessment, and sustainability insights
Case Studies in Thermal Engineering
Geothermal energy
Natural gas liquefaction
Thermodynamic analysis
Thermoeconomic analysis
title Thermoeconomic optimization of a geothermal-assisted hybrid LNG and power generation system: Simulation, performance assessment, and sustainability insights
title_full Thermoeconomic optimization of a geothermal-assisted hybrid LNG and power generation system: Simulation, performance assessment, and sustainability insights
title_fullStr Thermoeconomic optimization of a geothermal-assisted hybrid LNG and power generation system: Simulation, performance assessment, and sustainability insights
title_full_unstemmed Thermoeconomic optimization of a geothermal-assisted hybrid LNG and power generation system: Simulation, performance assessment, and sustainability insights
title_short Thermoeconomic optimization of a geothermal-assisted hybrid LNG and power generation system: Simulation, performance assessment, and sustainability insights
title_sort thermoeconomic optimization of a geothermal assisted hybrid lng and power generation system simulation performance assessment and sustainability insights
topic Geothermal energy
Natural gas liquefaction
Thermodynamic analysis
Thermoeconomic analysis
url http://www.sciencedirect.com/science/article/pii/S2214157X25006860
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AT nehirtokgoz thermoeconomicoptimizationofageothermalassistedhybridlngandpowergenerationsystemsimulationperformanceassessmentandsustainabilityinsights
AT safiyenurozdemir thermoeconomicoptimizationofageothermalassistedhybridlngandpowergenerationsystemsimulationperformanceassessmentandsustainabilityinsights