Nashrieh Shimi va Mohandesi Shimi Iran

Nashrieh Shimi va Mohandesi Shimi Iran

Energy Analysis of Simultaneous Polygeneration of Green Dimethyl Ether, Clean Electricity, Hot Steam and Fresh Water Using Geothermal Energy and Seawater

Document Type : Research Article

Authors
Armin Fazlinezhad 1
Bita Karimi 2
Armin Hasanpour 3
1 Department of Chemical Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, I.R. IRAN
2 Faculty of Chemical and Petroleum Engineering, Semnan University, Semnan, I.R. IRAN
3 Faculty of Chemical and Materials Engineering, Shahrood University of Technology, Shahrood, I.R. IRAN
Abstract
This research focuses on the production of green dimethyl ether (DME) through the hydrogenation of recycled CO₂. The hydrogen required is provided by water electrolysis and the CO₂ is collected from industries. These materials are first converted to methanol and then to DME. Initial simulations showed the energy efficiency of this process to be 51.27%. To provide the clean electricity required for the electrolysis, two Rankine cycles (with geothermal fluid as the energy source) - one high temperature and one low temperature - were integrated into the main process. This integration not only provided the electricity required for the electrolysis (1318 kW) and the entire unit, but also produced an additional 432 kW of clean electricity. In addition, 7.5 tons per hour of fresh water (from seawater desalination) and 7.5 tons per hour of hot steam at 240 degrees Celsius were recovered from the waste heat of the cycles for heating purposes. Combining these systems with a geothermal source increased DME production to 66 kg/h and significantly increased the overall energy efficiency of the process to 75.3%. Optimization of the thermal networks with pinch analysis also resulted in the complete elimination of the auxiliary heating load (heater) and an 11% reduction in the auxiliary cooling load (cooler) (kW). Sensitivity analysis showed that a 10% increase in electrolysis power (kW), a 50% decrease in the methanol reactor temperature (degrees Celsius), and a 33% decrease in the H₂ to CO₂ ratio in the methanol unit feed (molar ratio) could increase DME production by 32% (kg/h) and increase the energy efficiency from 75.3% to 75.7%. This energy efficiency is considered very high compared to similar studies.
Keywords
Water electrolysis
Methanol synthesis
Green dimethyl ether
Geothermal energy
Rankine cycle
Energy analysis

Subjects

[1]    Stewart K., Lair L., De La Torre B., Phan N.L., Das R., Gonzalez D., Lo R.C., Yang Y., Modeling and Optimization of an Alkaline Water Electrolysis for Hydrogen Production, in: 2021 IEEE Green Energy and Smart Systems Conference (IGESSC), IEEE, Long Beach, CA, USA, 1-6 (2021).
[2]    Amores E., Sánchez M., Rojas N., Sánchez-Molina M., Renewable Hydrogen Production by Water Electrolysis, in: Sustainable Fuel Technologies Handbook, Elsevier, 271-313 (2021).
[3]    Papadias D.D., Peng J.-K., Ahluwalia R.K., Hydrogen Carriers: Production, Transmission, Decomposition, and Storage, International Journal of Hydrogen Energy, 46: 24169-24189 (2021).
[4]    Niu J., Liu H., Jin Y., Fan B., Qi W., Ran J., Comprehensive Review of Cu-Based CO2 Hydrogenation to CH3OH: Insights from Experimental Work and Theoretical Analysis, International Journal of Hydrogen Energy, 47: 9183-9200 (2022).
[5]    Chernyak S.A., Corda M., Dath J.-P., Ordomsky V.V., Khodakov A.Y., Light Olefin Synthesis from a Diversity of Renewable and Fossil Feedstocks: State-of the-Art and Outlook, Chem. Soc. Rev., 51: 7994-8044 (2022).
[6]    Fasihi M., Breyer C., Global Production Potential of Green Methanol Based on Variable Renewable Electricity, Energy Environ. Sci., 17: 3503-3522 (2024).
[7]    Muazzam Y., Yousaf M., Zaman M., Elkamel A., Mahmood A., Rizwan M., Adnan M., Thermo-Economic Analysis of Integrated Hydrogen, Methanol and Dimethyl Ether Production Using Water Electrolyzed Hydrogen, Resources, 11: 85 (2022).
[8]    Abousalmia A., Karagoz S., Design and Simulation of an Integrated Process for the Co-Production of Power, Hydrogen, and DME by Using an Electrolyzer’s System, Energies, 18: 2446 (2025).
[9]    Xu W., Yang L., Niu Z., Wang S., Wang Y., Zhu Z., Cui P., Thermodynamic and Economic Analysis of a Novel DME-Power Polygeneration System Based on the Integration of Biomass Gasification and Alkaline Electrolysis of Water for Hydrogen Production, Energy, 314: 134185 (2025).
[10] Alotaibi M.M., Alturki A.A., Optimizing Renewable Energy Integration for Sustainable Fuel Production: A Techno-Economic Assessment of Dimethyl Ether Synthesis via a Hybrid Microgrid-Hydrogen System, Fuels, 5: 176-209 (2024).
[11]  Schreiber A., Troy S., Weiske S., Samsun R.C., Peters R., Zapp P., Kuckshinrichs W., Comparative Well-to-Tank Life Cycle Assessment of Methanol, Dimethyl Ether, and Oxymethylene Dimethyl Ethers Via the Power-to-Liquid Pathway, Journal of CO2 Utilization, 82: 102743 (2024).
[12] De Falco M., Natrella G., Capocelli M., Popielak P., Sołtysik M., Wawrzyńczak D., Majchrzak-Kucęba I., Exergetic Analysis of DME Synthesis from CO2 and Renewable Hydrogen, Energies, 15: 3516 (2022).
[13] Xu W., Zhang J., Wu Q., Wang Y., Zhao W., Zhu Z., Wang Y., Cui P., Energy, Exergy and Economic (3E) Analyses of a Novel DME-Power Polygeneration System with CO2 Capture Based on Biomass Gasification, Applied Energy, 374: 124031 (2024).
[14] Bianchi F.R., Risso R., Cardona L., Bove D., Cannizzaro F., Bonardi L., Palmisani E., Bosio B., Feasibility analysis of e-Hydrogen, e-Ammonia and e-Methanol Synthesis Compared with Methane to Fuel Production, Fuel, 384: 133938 (2025).
[15] Im-orb K., Piroonlerkgul P., Sustainability Analysis of the Bio-Dimethyl Ether (Bio-DME) Production Via Integrated Biomass Gasification and Direct DME Synthesis Process, Renewable Energy, 208: 324-330 (2023).
[16]    Perera J.A., Ng Z.W., Salema A.A., Chew I.M.L., Exergy Analysis of Integrated Methanol and Dimethyl-Ether Co-production Towards Net Zero Waste Emission, Bioenerg. Res., 17: 2282-2298 (2024).
[17] Zhang L., Asadollahzadeh M., Seikh A.H., Agrawal M.K., Minzha W., Proposal and Comprehensive Study of an Integrated Polygeneration Process Relying on Landfill Gas, Renewable Hydrogen, and binary geothermal cycle, Separation and Purification Technology, 327: 124897 (2023).
[18] Mirshafiee S.A., Kahani M., Ahmadi M.H., Energy and Exergy Analysis of a Multi-Generation System for Power, Freshwater, and Hydrogen Production Using Geothermal Water, J Therm Anal Calorim (2025).
[19] آرمین اوکاتی.، محمدرضا خانی.، بابک شکری.، شبیه‌سازی فرایند گازی‌سازی پلاسمایی زیست‌توده با استفاده از نرم‌افزار اسپن‌پلاس، نشریه شیمی و مهندسی شیمی ایران، 42(2): 365 تا 372 (1402).
[20] Adnan M.A., Fajar Mukti N.I., Dimethyl Ether as a Future Energy Vector: Economic Feasibility and Environmental Sustainability, Renewable Energy, 256: 124043 (2026).
[21] Kofler R., Campion N., Hillestad M., Meesenburg W., Clausen L.R., Techno-Economic Analysis of Dimethyl Ether Production from Different Biomass Resources and Off-Grid Renewable Electricity, Energy Fuels, 38: 8777-8803 (2024).
[22] Mangalindan J.R., Mahnaz F., Vito J., Suphavilai N., Shetty M., Tandem Cu/ZnO/ZrO2 -SAPO-34 System for Dimethyl Ether Synthesis from CO2 and H2 : Catalyst Optimization, Techno-Economic, and Carbon-Footprint Analyses, ACS Eng., Au 5: 267-283 (2025).
[23] Quang Vinh H., Phi Yen D.H., Tan L.M., Viet T.T., techno-Economic and Environmental Assessment for a Polygeneration and Low Emission Bio-Dme Production from Rice Straw in Vietnam, AEJ, 15: 65-76 (2025).
[24] Styring P., Sanderson P.W., Gell I., Skorikova G., Sánchez-Martínez C., Garcia-Garcia G., Sluijter S.N., Carbon Footprint of Power-to-X Derived Dimethyl Ether Using the Sorption Enhanced DME Synthesis Process, Front. Sustain., 3: 1057190 (2022).
[25] Peng S., Tang Y., Tang J., Wang X., Liang X., Huang H., Zheng Z., Ma X., Renewable Dimethyl Ether Production Under the Integration from Municipal Solid Waste Oxy-Fuel Combustion and Water Electrolyze: Insights from advanced exergy and exergoeconomic perspectives, International Journal of Hydrogen Energy, 141: 253-265 (2025).
[26] Zhang S., Wang S., Cui Z., Li K., Tian W., Co-Gasification Polygeneration System Based on Multi-Criteria Evaluation and Machine Learning Optimization for the Synergistic Valorization of Biomass and Plastic Waste, Energy Conversion and Management, 345: 120334 (2025).
[27] Zhou J., Ren J., Zhu L., He C., Turning Waste Into Energy Through a Solar-Powered Multi-Generation System With Novel Machine Learning-Based Life Cycle Optimization, Chemical Engineering Science, 307: 121348 (2025).
[28] فربد آل عزیز.، نسیم طاهونی.، محمدحسن پنجه شاهی.، تامین هیدروژن و الکتریسیته موردنیاز یک واحد تولید الفین با استفاده از انرژی‌های تجدیدپذیر, نشریه شیمی و مهندسی شیمی ایران، 43(2): 93 تا 111 (1403).
[29] مجید سعیدی.، مریم صفری پور.، بررسی روش­های بازیابی و مدیریت گازهای دورریز واحدهای صنعتی به منظور بازگشت به چرخه انرژی، نشریه شیمی و مهندسی شیمی ایران، 41(4): 327 تا 354 (1401).
[30] حانیه پورعلی.، پیمان تقوی ایشکوه.، رضا خوش بین.، عرفان آقایی.، آنالیز تعادل ترمودینامیکی تولید هیدروژن به روش فرایند ریفورمینگ خشک متان با استفاده از روش حداقل سازی انرژی آزاد گیبس، نشریه شیمی و مهندسی شیمی ایران، 42(2): 405 تا 417 (1402).
[31] Keshavarz H., Heydarinasab A., Vaziri A., Ardjmand M., Multi Objective Optimization of Shell and Tube Heat Exchanger with PCM Based Nanofluid Using Exergy Analyses and Adoptive Genetic Algorithm, Iran. J. Chem. Chem. Eng.(IJCCE), 43(10): 3772-3783 (2024).
[32] Niksirat M., Riyazat E., Rezakhani N., Feasibility Assessment of Using Refuse Derived Fuel as an Energy Source of the Multi-Effect Desalination with Thermal Vapor Compression of Seawater Desalination System, Iran. J. Chem. Chem. Eng.(IJCCE), 43(8): 3079-3087 (2024).
[33] Beck A., Newton M.A., Van De Water L.G.A., Van Bokhoven J.A., The Enigma of Methanol Synthesis by Cu/ZnO/Al2 O3 -Based Catalysts, Chem. Rev., 124: 4543-4678 (2024).
[34] Bi X., Wang G., Cui D., Qu X., Shi S., Yu D., Cheng M., Ji Y., Simulation Study on the Effect of Temperature on Hydrogen Production Performance of Alkaline Electrolytic Water, Fuel, 380: 133209 (2025).
[35] Puig-Gamero M., Argudo-Santamaria J., Valverde J.L., Sánchez P., Sanchez-Silva L., Three Integrated Process Simulation Using Aspen Plus®: Pine Gasification, Syngas Cleaning and Methanol Synthesis, Energy Conversion and Management, 177: 416-427 (2018).
[36] Moura C.P.C., De Araujo Filho M.A., Villardi H.G.D., Cavalcante R.M., Young A.F., Process Simulation and Economic Evaluation of an Integrated Production Plant for Methanol, Acetic Acid and DME Synthesis Via Sugarcane Bagasse Gasification, Energy Conversion and Management, 286: 117051 (2023).
[37] Luyben W.L., Improving The Conventional Reactor/Separation/Recycle DME Process, Computers & Chemical Engineering, 106: 17-22 (2017).
[38] Alirahmi S.M., Assareh E., Pourghassab N.N., Delpisheh M., Barelli L., Baldinelli A., Green Hydrogen & Electricity Production Via Geothermal-Driven Multi-Generation System: Thermodynamic Modeling and Optimization, Fuel, 308: 122049 (2022).
[39] Gambou F., Guilbert D., Zasadzinski M., Rafaralahy H., A Comprehensive Survey of Alkaline Electrolyzer Modeling: Electrical Domain and Specific Electrolyte Conductivity, Energies, 15:  3452 (2022).
[40] Moossa B., Trivedi P., Saleem H., Zaidi S.J., Desalination in the GCC Countries- A Review, Journal of Cleaner Production, 357:  131717 (2022).