Iranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-853713220260308Energetic and Exergetic Analysis of a Geothermal Energy System for Multigeneration Applications: A Thermodynamic Perspective7582168310.22104/hfe.2025.7169.1324ENGhanim Kadhim NaserAl-ShammariMechanical Engineering Department, Faculty of Engineering, Urmia University, Urmia, IranMajidAbbasalizadehMechanical Engineering Department, Faculty of Engineering, Urmia University, Urmia, Iran0000-0002-5269-0037IrajMirzaeeMechanical Engineering Department, Faculty of Engineering, Urmia University, Urmia, Iran0000-0002-3523-5251Journal Article20251220Recent research has increasingly focused on high-efficiency systems powered by renewable energy sources to address global warming, prevent ozone layer depletion, and ensure stable and accessible energy supplies. Among these sources, geothermal energy stands out for its ability to power thermodynamic systems capable of generating multiple outputs. The efficiency of a stand-alone flash-binary geothermal power plant decreases due to input energy losses. To enhance overall performance and reduce costs, structural modifications and waste heat recovery techniques can be implemented. This study proposes and investigates an innovative waste heat recovery system integrated into a dual-flash binary geothermal power plant. The combined system incorporates a Rankine cycle and a proton exchange membrane electrolyzer. The system focuses on two major processes: converting waste heat into power and producing hydrogen from the generated power. Its feasibility is evaluated from thermodynamic and economic perspectives. The system analysis was performed using EES (Engineering Equation Solver) software. Results indicate energy and exergy efficiencies of 23.97% and 35.35%, respectively. Moreover, the total power generated by the system, incorporating two turbines and two thermoelectric generators (TEGs), is 5981 kW. The system also produces hydrogen at a rate of 0.0295 kg/s. Moreover, based on the exergy destruction analysis, TEG 2 and the compressor exhibit the highest rates of exergy destruction.https://hfe.irost.ir/article_1683_fddd7938a71db5f81fcc621673ab67b7.pdfIranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-853713220260305A Critical Review of Continuous Biohydrogen Production83104169610.22104/hfe.2025.7307.1336ENAtefehFarjadmaneshDepartment of Biotechnology, Iranian Research Organization for Science and Technology (IROST), Tehran, IranKhosrowRostamiDepartment of Biotechnology, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran0000-0002-3111-5690FatemehBoshaghSchool of Chemical Engineering and Materials Science, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea0000-0002-4774-9356Journal Article20251129Biohydrogen is a feasible and environmentally sustainable fuel for the world's growing energy demand. As an alternative renewable energy source, hydrogen contains 2.75 times more energy per gram than any other known source. Biohydrogen is produced from various microorganisms and renewable materials through anaerobic dark fermentation and phototrophic bacteria, operating in batch, semi-continuous, and continuous modes. Anaerobic dark fermentation has a higher production rate and yield compared to photo-fermentation. In this review, the dark fermentation of hydrogen is discussed concerning key influential parameters and environmental factors such as temperature, pH, hydraulic retention time, mass transfer coefficient, and recycle ratio. A low initial pH affects metabolic pathways, prolongs the lag phase, and enhances Fe-hydrogenase activity. Mesophilic, thermophilic and ultrathermophilic strains could tolerate maximum operating temperature of 40, 65 or 108°C, respectively. A varity of fermenters are continuously used for biohydrogen production, with a few discussed here. Tower-type fermenters are more feasible than CSTRs as they provide a higher hydraulic retention time for continuous biohydrogen production. Fluidized beds are used for both short- and long-term hydraulic retention time operations. Hydraulic retention time (HRT) typically depends on the bioreactor type, geometry, and feed composition, particularly the carbon source. When wastewater is used, HRT generally ranges from 8 to 14 hours. However, the process requires more detailed data to fully understand and overcome thermodynamic limitations. These limitations could be addressed through genetic modification or metabolic pathway alterations to enhance biohydrogen yield, making large-scale and commercial production more feasible.https://hfe.irost.ir/article_1696_5cf21ce30208cfffaa832c6e44bb567d.pdfIranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-853713220260601Investigating Numerically the Impact of Phase Change Materials on Heat Exchangers to Optimize Energy Consumption105112169710.22104/hfe.2026.7415.1344ENSeyyed AmirrezaAbdollahiDepartment of Mechanical Engineering, Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran0000-0002-9576-7989Seyed KazemYekaniDepartment of Mechanical Engineering, Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran0009-0000-9484-9301Seyyed FaramarzRanjbarDepartment of Mechanical Engineering, Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran0000-0001-5154-4786Seyed EsmailRazaviDepartment of Mechanical Engineering, Faculty of Mechanical Engineering, University of Tabriz, Tabriz, IranMostafaBarzegar GerdroodbaryDepartment of Mechanical Engineering, Iranian Research Organization for Science and Technology (IROST), Tehran, IranDepartment of Electromechanical Engineering, C-MAST-Center for Mechanical and Aerospace Science and Technology, Universidade da Beira Interior, Covilha, PortugalJournal Article20251211This article presents a novel three‑dimensional numerical investigation of turbulent water–air flow and displacement heat transfer in a shell‑and‑tube heat exchanger enhanced with paraffin phase‑change material (PCM) and aluminum oxide nanoparticles. Covering Reynolds numbers from 0 to 3 000, the governing equations are solved via the finite‑volume method.The study's findings indicate that employing phase-change material surrounding the tube and keeping a steady heat flux can both increase a shell and tube heat exchanger's penetration coefficient. The impact of this modification has been compared to that of a straight, circular tube, providing practical insights for heat exchanger design. The chosen fluid flow exhibits turbulence as it moves through the tube and collides with the thermal boundary layer, increasing the internal transfer coefficient of the fluid flow. The findings show an insignificant error of 8.71\% for the grid independence section.https://hfe.irost.ir/article_1697_673271cc47c1a4e77f57e239ed4d28a7.pdfIranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-853713220260601Feasibility of Fabricating a Defect-Free Nickel Composite Membrane Using the Organic-Inorganic Activation Technique113124168010.22104/hfe.2025.7498.1350ENMinaOmidifarNanostructure Material Research Center (NMRC), Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz, IranAli AkbarBabalouNanostructure Material Research Center (NMRC), Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town,
Tabriz, Iran0000-0002-6985-4149Journal Article20251113This study presents a novel fabrication method for metal/ceramic membranes, providing a cost-effective substitute for traditional, expensive Pd-based membranes. While nickel offers a promising replacement for Pd-based membranes, its effectiveness in H<sub>2</sub> separation depends on whether it can function independently or must be incorporated into Pd-based alloys to enhance performance and reduce fabrication costs. To investigate this, a homogeneous and thin (2 µm) nickel composite membrane was fabricated with the organic-inorganic activation (OIA) process in the electroless plating (ELP) technique for the first time. At 25°C and a differential pressure of 400 kPa, the hydrogen flux of the membrane was measured at 3.26×10<sup>-2</sup> molm<sup>-2</sup> s<sup>-1</sup>, with a separation factor of 3 for H<sub>2</sub>/N<sub>2</sub>. The findings demonstrated that Knudsen diffusion was the prevailing mechanism for H<sub>2</sub> transport across the membrane.https://hfe.irost.ir/article_1680_11d0e6287202fced83f79975ec59a3a6.pdfIranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-853713220260307Boosting Mg-Air Battery Efficiency with Polyaniline-Coated Anodes125136169810.22104/hfe.2025.7564.1353ENFatemehParvinzadehHydrogen and Fuel Cell Research Laboratory, Chemistry Department, Yasouj University, Yasouj, IranMehdiKheirmandHydrogen and Fuel Cell Research Laboratory, Chemistry Department, Yasouj University, Yasouj, IranChemistry Department, School of Basic Sciences, Yasouj University, PO Box 75918-74934, Yasouj, Iran0000-0002-6469-7797ParisaAkbarianHydrogen and Fuel Cell Research Laboratory, Chemistry Department, Yasouj University, Yasouj, Iran0009-0006-7045-099XJournal Article20251124Despite the abundance and high density of Mg metal as an anode, the limited development of Mg-air batteries is primarily due to the surface reactions of the Mg anode in water-based electrolytes. A reliable strategy to improve metal anode efficiency is to prevent anode surface reactions by designing and applying suitable protective coatings. In this study, a polyaniline (PANI) polymer coating was designed and synthesized to modify the surface of Mg anodes. The primary scope of this research is to examine the effect of coating on the Mg anode surface and its ability to control surface reactions, including corrosion. Electrochemical analyses confirm the optimal efficiency of the PANI coating in inhibiting the corrosion of the surfaces of Magnesium, as evidenced by comparisons between uncoated and PANI-coated samples. As a result, Mg with PANI coating has a smaller corrosion current and a larger corrosion potential (5.06×10<sup>-5</sup> A/cm<sup>2</sup>, 1.01 V) than uncoated Mg (6.3×10<sup>-4</sup> A/cm<sup>2</sup>, 1.49 V), respectively. Because of its chemical durability and good electrochemical behavior, PANI can overcome the limitations of using Mg anodes as a protective surface coating, improving the efficiency of Mg-air batteries and developing new technologies.https://hfe.irost.ir/article_1698_9fe97fff97f089661135d0487843108e.pdfIranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-853713220260308Thermo-Economic Analysis of a Geothermal-based Multigeneration System Using the Kalina Cycle for Power, Heating, Cooling, Hydrogen and Freshwater Production137148169910.22104/hfe.2025.7588.1356ENArkanJabbar Farhan FarhanFaculty of Mechanical Engineering, University of Urmia, IranMajidAbbasalizadehFaculty of Mechanical Engineering, University of Urmia, Iran0000-0002-5269-0037ShahramKhalilaryaFaculty of Mechanical Engineering, University of Urmia, Iran0000-0002-6434-852XSamadJafarmadarFaculty of Mechanical Engineering, University of Urmia, Iran0000-0001-5029-8456Journal Article20251028This study presents an in-depth thermodynamic and economic evaluation of a hybrid geothermal energy system utilizing Kalina cycle technology for multipurpose power generation. The system is designed to produce electricity and heating while supplying cooling, hydrogen, and freshwater. The integrated system reaches a total energy efficiency of 47.6\% and an exergy efficiency of 44.2%. Raising the high pressure setting in the Kalina cycle to 4900 kPa reduces the exergy destruction cost rate to $1486.49/h, the total cost rate to $2464.12/h, and the capital investment rate to $922.12/h, compared to the base pressure of 4000 kPa where these rates were $1912.08/h for exergy destruction and \$3084.00/h for total cost and $1171.92/h for capital investment. The exergetic assessment shows Turbine 2 and the Compressor as the main contributors to system exergy destruction, with outputs of 2545.33 kW and 2353.09 kW, respectively. At a rate of 0.1524 kg/h the system establishes two operational capabilities: hydrogen production and a cooling output of 3498 kW. The research indicates that the combined multigeneration system enhances resource utilization ofgeothermal energy by maximizing energy efficiency and decreasing operational costs.https://hfe.irost.ir/article_1699_ef2a4be5473ab0b3cc286e67b1f59f44.pdfIranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-853713220260308Thermoeconomic Analysis and Optimization of a Novel Geothermal Energy-Based Multigeneration System for Liquid Hydrogen, Hot Water, Cooling and Power Production149166170010.22104/hfe.2025.7627.1362ENAliEyvaziDepartment of Mechanical Engineering, Faculty of Engineering, Vali-e-Asr University of Rafsanjan, Rafsanjan, IranMehranAmeriDepartment of Mechanical Engineering, Faculty of Engineering, Shahid bahonar University of Kerman, Kerman, IranMohammadShafiey DehajDepartment of Mechanical Engineering, Faculty of Engineering, Vali-e-Asr University of Rafsanjan, Rafsanjan, IranHadiGhaebiDepartment of Mechanical Engineering, Faculty of Engineering, University of Mohaghegh Ardabili, Ardabil, IranJournal Article20251102This study examines a sustainable energy framework designed for hydrogen production. It includes various components like a geothermal energy module, a Claude cycle system for hydrogen liquefaction, and a modified organic Rankine cycle. A detailed investigation into its operational features is conducted across various aspects, with its energy conversion efficiency measured using key performance indicators. The assessment of operational effectiveness was based on factors such as energy yield, exergy utilization, and economic considerations. A sensitivity analysis assesses how changes in operation affect performance. A dual-objective genetic algorithm with the TOPSIS method enhances the hydrogen production infrastructure. The system achieves an energy conversion efficiency of 45% and exergy efficiency of 53%, producing 4.88 kg of hydrogen per hour and 1,425 kW of power, with operational costs of $37.16 per hour. The Levelized Cost of Energy is 19.8 cents per kWh, while the Levelized Cost of Hydrogen is 24.39 $/kg. The energy needed for hydrogen liquefaction is reduced through a two-stage thermal management strategy.https://hfe.irost.ir/article_1700_01e00f2f4bfcbb7505cb641066f2859b.pdfIranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-853713220260601Thermodynamic and Thermoeconomic Analysis of the Use of Wind and Solar Energy to Supply the Energy Requirements of a Multigeneration System167186164510.22104/hfe.2025.7766.1374ENArashGarmabiDepartment of Mechanical Engineering, Urmia University of Technology, Urmia, IranSajadRezazadehDepartment of Mechanical Engineering, Urmia University of Technology, Urmia, Iran0000-0002-9436-3798FarzadMohammadkhaniDepartment of Mechanical Engineering, Urmia University of Technology, Urmia, Iran0000-0003-3399-3099Journal Article20251105The current paper provides a thermodynamic, and thermoeconomic analysis of a new multigenerational energy system consisting of the solar thermal energy source and the wind source. This consists of a Brayton cycle driven by a solar tower, a Steam Rankine Cycle (SRC) with feedwater heater and makeup condensate pump, an Organic Rankine Cycle with ejector refrigeration (ORC-ERC), a thermoelectric generator (TEG), a proton exchange membrane (PEM) electrolyzer and a reverse osmosis (RO) desalination plant so that electricity, hydrogen, freshwater, heating, cooling and domestic hot water are produced simultaneously. It has overall annual power output of 38.37 MW, thermal efficiency of 25.22\% and exergy efficiency of 50.7\%. The saltwater has a desalting rate of 0.008 kg/s and hydrogen at 19.37 kg/s. The greatest exergy losses can be found in the solar collector, compressors and the combustion chamber pointing out to the areas where improvements can be introduced. From Thermoeconomic point of view, gas turbine is deemed to be capital intensive and the solar collector and wind turbine are highly cost effective. Sensitivity studies show that raising the gas turbine inlet temperature and increment of the pressure ratio of the compressor will boost the performance considerably. All in all, the suggested pathway is not only a technically viable and financially beneficial model of clean, diversified energy production with affinities to locations that have plentiful resources of both solar and wind power.https://hfe.irost.ir/article_1645_c1fea270c48e8079d8ddf7d06d26ab52.pdf