http://hdl.handle.net/20.500.12566/19 Fri, 10 Apr 2026 13:18:31 GMT 2026-04-10T13:18:31Z http://hdl.handle.net/20.500.12566/2359 Energy and exergy analyses of an advanced combined cycle fired by natural gas and biomass Sharafi Laleh, Shayan; Mahmoudi, S.M.S; Soltani, Saeed; Morosuk, Tatiana A modified combined cycle with an intercooler and a reheater (CCIR) within the gas-turbine system is proposed and evaluated. The fuel for the combustion chamber is natural gas, and the fuel for the reheater is provided by gasified biomass. Adding an intercooler between two compressors and a preheater for the compressed air before entering the combustion chamber increases the efficiency of the overall system. A further increase in efficiency was achieved through the utilization of the heat of the exiting hot gases in a Rankine cycle. The system has a fixed power output of 10 MW. The system's improvements resulted in 56.3% of the overall energy efficiency and 50.7% of the exergy efficiency. Natural gas and biomass flow rates are 0.139 kg/s and 0.776 kg/s, respectively. Mon, 01 Jan 2024 00:00:00 GMT http://hdl.handle.net/20.500.12566/2359 2024-01-01T00:00:00Z http://hdl.handle.net/20.500.12566/2358 Exploring the challenges of integrating geothermal energy in sport spots: A multi method research design Safarpour, Ali; Altındal, Emine; Soltani, Saeed; Rosen, Marc A. Recently, the global need for renewable and sustainable energy reservoirs has gained significant momentum. Among the multiple renewable energy options, geothermal energy stands a particularly advantageous and promising option. This research provides useful information to support sustainable development via clean energy use in sports facilities. A mixed-methods is used, including a qualitative section (interview with experts and reviewing the previous papers), and two survey sections to validate the challenges. 23 experts participated in the qualitative section and initial variables were identified. There were 123 participants in survey one, and the data were analyzed by exploratory factor analysis (EFA) and there were 137 participants in survey two, and the data were used for confirmatory factor analysis (CFA). to ensure adherence to subject-to-item ratio guidelines (5:1 for EFA, 10:1 for CFA) and statistical power for robust factor analysis. The results identified six main challenges and 18 sub-challenges. It was found that financial aspects pose a key challenge, as the upfront costs of installing geothermal systems can be higher compared to traditional energy sources. Another significant challenge is the scarcity of awareness and comprehension of geothermal technology. Technical complexities, as drilling and heat exchange system design, require specialized knowledge and expertise. Some practical options are presented for establishing geothermal energy use in sport facilities, including (1) financial incentives (e.g., government subsidies, public-private partnerships), (2) awareness campaigns targeting facility managers and policymakers, (3) technical training programs for geothermal system maintenance, and (4) streamlined permitting processes to reduce bureaucratic barriers. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/20.500.12566/2358 2025-01-01T00:00:00Z http://hdl.handle.net/20.500.12566/2357 Techno-economic optimization of an integrated ammonia–methane synthesis system powered by LNG-assisted biogas oxy-fuel cycle and vanadium chloride hydrogen production Sharafi Laleh, Shayan; Rabet, Shayan; Sadat Rezaei Mousavi, Haniyeh; Yari, Mortaza; Soltani, Saeed; Saberi Mehr, Ali This study presents a novel multi-generation biogas-fueled power system integrating oxy-fuel combustion and thermochemical hydrogen production for simultaneous power generation, synthetic fuel production, and carbon management. The system combusts biogas with pure oxygen, produced via cryogenic air separation using LNG cold energy, in three sequential combustion chambers and turbines. High-temperature exhaust gases are directed to a vanadium chloride (VCl) thermochemical cycle for hydrogen production and an Organic Rankine Cycle (ORC) for additional power recovery. At the same time, radiative heat from the combustion chambers is converted to electricity through thermophotovoltaic (TPV) units. Separated hydrogen is divided between methanation and ammonia synthesis units, using CO2 from the final exhaust and nitrogen from air separation. Thermodynamic, techno-economic, and environmental analyses were conducted, followed by a multi-objective optimization using the Gray Wolf Optimizer. One scenario targeted maximum net power and exergetic efficiency with minimized product cost, another emphasized environmental impact reduction, and the third balanced subsystem exergetic efficiency with product cost. In the first case, the system achieved a net power output of 12,023.05 kW, an exergetic efficiency of 47.60 %, and a product cost of 19.21 $/GJ. The environmental-focused case reduced the environmental index to 0.4063 $/kWh with a product cost of 19.50 $/GJ, while the balanced case reached an exergetic efficiency of 45.23 %, a product cost of 19.12 $/GJ, and an environmental index of 0.4030 $/kWh. Increasing ammonia and methane prices to 1.6 $/kg and 0.6 $/kg shortened the payback period from 5.71 to 4.5 years. These results demonstrate the system's high efficiency, economic resilience, and renewable energy potential. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/20.500.12566/2357 2025-01-01T00:00:00Z http://hdl.handle.net/20.500.12566/2356 A novel multi-generation system integrating thermophotovoltaic and SOFC system for power and green hydrogen with CO2 liquefaction: A techno-economic and multi-objective optimization study Rabet, Shayan; Sharafi Laleh, Shayan; Habibi, Omid; Sadri Jahanshahi, Seyed Ali; Yari, Mortaza; Soltani, Saeed This study proposes a novel biomass-fueled multi-generation system that addresses key limitations in existing SOFC-based configurations, such as unutilized radiative heat and the lack of integrated CO2 capture. The system integrates a digestion unit, solid oxide fuel cell (SOFC), thermophotovoltaic (TPV) unit, closed Brayton cycle, vanadium chloride hydrogen production cycle, and a CO2 liquefaction module. A major innovation lies in recovering the SOFC's radiative waste heat via the TPV unit, significantly boosting total power output and improving overall sustainability. The system utilizes biogas and air in separate pathways for electrochemical and combustion processes, while waste heat is recovered to drive the Brayton cycle, support hydrogen production, and enable CO2 liquefaction through LNG-based cooling. This integrated approach reduces fossil fuel dependency and greenhouse gas emissions. A comprehensive energy, exergy, techno-economic, and environmental analysis is performed, along with multi-objective optimization using the Grey Wolf Optimizer under two scenarios. Parametric studies identify the combustion chamber temperature as a key performance driver. The integration of TPV and cryogenic CO2 capture improves energy utilization and environmental impact. The optimized system achieves a net power output of 2,798 kW, an exergy efficiency of 35.44 %, and a CO2 emission index of 0.6353 kg/kWh. The system achieves a hydrogen production rate of 0.01285 kg/s, with payback periods ranging from under four to under seven years depending on electricity price and operational lifespan. These results confirm the proposed system's potential as a high-efficiency, low-emission solution for decentralized clean energy and fuel production. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/20.500.12566/2356 2026-01-01T00:00:00Z