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This paper presents an analysis and optimization of a polygeneration power-production system that integrates a concentrating solar tower, a supercritical CO2 Brayton cycle, a double-flash geothermal Rankine cycle, and an internal combustion engine. The concentrating solar tower is analyzed under the weather conditions of the Mexicali Valley, Mexico, optimizing the incident radiation on the receiver and its size, the tower height, and the number of heliostats and their distribution. The integrated polygeneration system is studied by first and second law analyses, and its optimization is also developed. Results show that the optimal parameters for the solar field are a solar flux of 549.2 kW/m2, a height tower of 73.71 m, an external receiver of 1.86 m height with a 6.91 m diameter, and a total of 1116 heliostats of 6 m × 6 m. For the integrated polygeneration system, the optimal values of the variables considered are 1437 kPa and 351.2 kPa for the separation pressures of both flash chambers, 753 °C for the gasification temperature, 741.1 °C for the inlet temperature to the turbine, 2.5 and 1.503 for the turbine pressure ratios, 0.5964 for the air–biomass equivalence ratio, and 0.5881 for the CO2 mass flow splitting fraction. Finally, for the optimal system, the thermal efficiency is 38.8%, and the exergetic efficiency is 30.9%. [ABSTRACT FROM AUTHOR]

Using polygeneration systems is one of the most cost-effective ways for energy efficiency improvement, which secures sustainable energy development and reduces environmental impacts. This paper investigates a polygeneration system powered by low- to medium-grade waste heat and using CO2 as a working fluid to simultaneously produce electric power, refrigeration, and heating capacities. The system is simulated in Aspen HYSYS® and evaluated by applying advanced exergy-based methods. With the split of exergy destruction and investment cost into avoidable and unavoidable parts, the avoidable part reveals the real improvement potential and priority of each component. Subsequently, an exergoeconomic graphical optimization is implemented at the component level to improve the system performance further. Optimization results and an engineering solution considering technical limitations are proposed. Compared to the base case, the system exergetic efficiency was improved by 15.4% and the average product cost was reduced by 7.1%; while the engineering solution shows an increase of 11.3% in system exergetic efficiency and a decrease of 8.5% in the average product cost. [ABSTRACT FROM AUTHOR]

The calculation method developed by the authors is supplemented by the heat balance of a circulating fluidized bed (CFB) reactor for burning coke residue in a CFB reactor‒gas-generator system. The following options are examined: with the supply of additional dried fuel to the reactor as an alternative method for keeping the required gasification temperature of particles at the CFB reactor outlet and application as a fuel of a mixture of wood biomass and Kuznetsk coal benefication products. The thermal cycle of the plant has been modified as applicable, and the calculation results are presented. It has been demonstrated that gasification of a mixture of biomass and coal benefication enables increasing the overall system capacity (production of hydrogen + electricity) without a considerable growth in the biomass consumption. In this case, the hydrogen production decreases, and the hydrogen production efficiency drops but the efficiency of electricity generation rises. The hydrodynamic calculation of CFB reactors was performed to attain the specified flowrates of circulating material required to maintain proper temperatures in the reactors. The flowrate of circulating particles can be increased by increasing the pressure difference (loading level or weight of material in the reactors). The overall dimensions of the reactors have been determined, and their layout is presented. A procedure for calculating capital and operating expenditures is outlined, and these expenditure components are estimated. The cost of hydrogen production using biomass without CO2 emission over the life cycle of the plant was estimated (USD 1.45/kg). Approximately 2/3 of the formed CO2 is already ready for storage. Therefore, we have only to remove CO2 from the flue gas flow from the CFB reactor of the gas generator. This level corresponds to available foreign data on similar plants operating on natural gas and is lower than that provided by the widely used technology of steam reforming of natural gas with CO2 capture. [ABSTRACT FROM AUTHOR]

Liquefied natural gas (LNG) regasification terminals have specification that necessitates adjustment of heating value of LNG feed. One strategy to reduce heating value is to separate heavier hydrocarbons from LNG by utilizing LNG cold energy. The amount of cold energy utilized in recovering heavy hydrocarbon is much less resulting in wastage of remaining cold energy. To reverse this wastage, we propose a polygeneration process that encompasses an organic Rankine cycle to generate electricity and refrigeration for cold storage warehouse cooling and data center cooling by utilizing remaining cold energy. Based on process simulation and optimization, we found that a significant amount of cold energy is utilized resulting in an avoided CO2 emission, thereby enhancing sustainability of an LNG regasification terminal. [ABSTRACT FROM AUTHOR]

Solar thermal energy-based electricity is capital-intensive, and complex while technically evolving to achieve an optimal design. Global commitments and timelines to increase renewable energy share in the grid have promoted technically mature solar photovoltaics and wind. However, the potential of solar thermal energy for industrial applications, cogeneration and polygeneration is on the back foot for lack of policy, complexity, technical readiness level, cost of components and workable business models. Solar collectors that can generate high-quality steam for power generation is complex and costly; while, modified version of linear Fresnel reflector's (LFR) are prospective for various requirements. The current work looks into the possibility of an LFR and heliostat combination to generate steam at 45 bar, 400C temperature to produce electricity. The levelized cost of electricity (LCOE) and levelized cost of water (LCOW) is found to be INR 5.11 kWh−1 and INR 43.03 m−3, in a 70:30 debt–equity scenario. An IRR of 8.55% is achieved with a payback of 12.5 years, with the sale of electricity at INR 10.11 kWh−1 and water at INR 45 m−3. To reduce the LCOE, LCOW and have an attractive IRR, the viability gap funding (VGF) as an option is tried out. The impact of VGF at, 0%, 10%, 20% and 30% on water generation, electricity generation, IRR, NPV and payback are found. It is found that as the VGF increase, there is a better generation cost for electricity and water, with an improved IRR. However, with the VGF trend and corresponding reduction in electricity and water production cost, it will be ideal to have the VGF close to 15% to keep the electricity sale price at approximately INR 8.5 kWh−1 and water pricing at INR 46 m−3. [ABSTRACT FROM AUTHOR]

Climate change and energy crises are twin challenges that require collective wisdom and polygeneration energy systems for sustainable development. Hydrogen is an abundant element in the universe that can shape the future of energy transmission and storage from electrons to molecules. This paper presents utilization of a solar PV assisted hydrogen and electricity production and storage system for a university transportation fleet of 43 student transit buses to reduce annual 9842 liter fuel consumption and 26.52 Mt CO 2 emissions. The system is designed, modeled, and simulated using TRNSYS® energy simulation software and optimized in TrnOpt linked to GenOpt for dynamic weather conditions of Gujrat (Pakistan), Fargo (USA), London (UK). As a model, the results of a 27kW p PV system are presented that assists an alkaline electrolyzer generating 12696 m3 hydrogen, 6348 m3 oxygen, 16848 KWh electricity exported to national grid and 11.56 GJ thermal energy annually. The proposed system generates energy vectors including hydrogen, electricity, heat, and oxygen with optimal performance during intermittent weathers. In this paper, a business model canvas is developed for solar PV assisted hydrogen production and storage system. These outputs can be accredited to the hydrogen as an energy alternative for green and sustainable future for transportation sector. [Display omitted] • A paradigm energy shift from electron to molecules for a sustainable future. • A Solar assisted polygeneration system is dynamically simulated and optimized in TRNSYS for various climate conditions. • Proposed 27kWp system effectively produces 12696 m³ hydrogen, 6348 m³ oxygen, and exports 16848 kWh electricity to grid. • The system cuts annual fuel consumption by 9842 liters for university fleet, reducing CO 2 emissions by 26.52 Mt annually. • Developed a business model for the sustainable application of solar PV-assisted hydrogen production in transportation. [ABSTRACT FROM AUTHOR]

With the increasing emphasis on decentralized smart grids, Micro Gas Turbines have gained prominence as a key energy generation system. This comprehensive review emphasizes the crucial role of integrating Techno-Economic Analysis with Micro Gas Turbines for effective energy management, demonstrated through a bibliometric analysis of energy research activities. This integration facilitates a holistic evaluation of the interplay between technical capabilities and economic feasibility, offering valuable insights for making trade-off assessments. The review critically examines the techno-economic analysis of Micro Gas Turbines, focusing on four major areas: integration with photovoltaic systems, configurations like cogeneration and trigeneration, optimization techniques, and hydrogen utilization. The review reveals that while standalone Micro Gas Turbines face economic challenges, their integration with photovoltaic and battery bank systems significantly improves cost-effectiveness, achieving a cost of electricity as low as $0.263/kWh. Additionally, the optimization of Micro Gas Turbine systems using advanced algorithms enhances energy efficiency by 10–15%, highlighting the importance of smart control systems and optimal component sizing. The economic viability of hydrogen-powered Micro Gas Turbines is also highlighted, with the levelized cost of hydrogen projected to decrease below €3 per kilogram by 2030, positioning these systems as competitive solutions aligned with carbon reduction goals. This comprehensive analysis not only identifies current challenges but also sets the direction for future research, emphasizing the need for cost reduction in solar conversion components, the development of standardized testing procedures, and exploration of hydrogen infrastructure impacts. Despite ongoing evolution, refining methodological guidelines and developing compatible tools remain crucial for successful technological integration, emphasizing the continued need for research to enhance the energy management strategies and improve the synergy between Techno-Economic Analysis and Micro Gas Turbine analysis. By focusing on these critical areas, this review provides a robust guideline for advancing Micro Gas Turbine technologies towards a sustainable energy future.

In this paper, the experimental results of the thermal sub-system of a reliable and cost-effective polygeneration solar system are presented. This polygeneration system produces heating, cooling, and electricity from solar energy, which is used in an existing test building. Heat is generated in four evacuated tube solar collectors (ETCs). The heat may be used for space cooling through a variable geometry ejector (VGE) heat pump. In order to reduce the mismatches between generation and consumption, two thermal storage tanks were added. The performance of a new thermal storage, with 400 L, able to store both sensible and latent heat, was tested. The heating performances of the test building were assessed. Ejector cycle tests were also performed, and the variation of the cooling coefficient of performance (COP) was calculated for different flow rates. For heating, the results showed that the heat storage was capable of heating the test building for 8 h, with temperatures between 22 °C and 26 °C. All results showed that this polygeneration prototype could be capable of meeting the heating and cooling needs when applied to a real building. [ABSTRACT FROM AUTHOR]

The primary scope of the present work is the comprehensive investigation of a novel multigeneration system that exploits renewable energy sources, i.e. solar energy, geothermal energy, and biomass, and produces four useful outputs, i.e. electricity, heating, cooling, and green hydrogen. Solar irradiation is the primary energy source, which is exploited by parabolic trough collectors and powers a supercritical CO 2 regenerative Brayton cycle, while a biomass boiler serves as an auxiliary energy input. In addition, the whole installation includes a proton exchange membrane water electrolyzer, a water heater, as well as an absorption chiller, where a geothermal well is used for heat rejection. Apart from the thermal energy storage tank, which is coupled with the collectors, hydrogen production is used as a secondary energy storage method, as the excess produced renewable electricity feeds the electrolyzer. Consequently, the installation is examined parametrically, and optimized on steady-state conditions. Then, a dynamic simulation study is conducted for the climate data of Athens, Greece. According to the results, at the optimum operation point on steady-state conditions, the energy efficiency is determined at 37.89%, and the exergy efficiency at 20.86%. Moreover, the annual energy and exergy efficiencies are defined at 32.52%, and 18.51%, respectively. The economic evaluation analysis indicates that the payback period is about 11 years, while the internal rate of return, and the net present value are determined at 10.62% and 7,753,905 €, respectively. In addition, the system is estimated to save 3072.6 tons of CO 2 equivalent per annum. In conclusion, the proposed multigeneration system can address the various energy needs and recent environmental challenges, as a totally renewable, economically feasible, and environmentally friendly solution. • A multigeneration system that produces four useful outputs is examined. • The unit exploits three renewable sources, solar, biomass, and geothermal. • Both steady-state and dynamic analyses are carried out. • The annual energy and exergy efficiencies are defined at 32.52% and 18.51%. • The system payback period is found at 11 years, while it saves 3072.6 tn CO2-eq. [ABSTRACT FROM AUTHOR]

This paper presents an analysis and optimization of a polygeneration power-production system that integrates a concentrating solar tower, a supercritical CO2 Brayton cycle, a double-flash geothermal Rankine cycle, and an internal combustion engine. The concentrating solar tower is analyzed under the weather conditions of the Mexicali Valley, Mexico, optimizing the incident radiation on the receiver and its size, the tower height, and the number of heliostats and their distribution. The integrated polygeneration system is studied by first and second law analyses, and its optimization is also developed. Results show that the optimal parameters for the solar field are a solar flux of 549.2 kW/m2, a height tower of 73.71 m, an external receiver of 1.86 m height with a 6.91 m diameter, and a total of 1116 heliostats of 6 m × 6 m. For the integrated polygeneration system, the optimal values of the variables considered are 1437 kPa and 351.2 kPa for the separation pressures of both flash chambers, 753 °C for the gasification temperature, 741.1 °C for the inlet temperature to the turbine, 2.5 and 1.503 for the turbine pressure ratios, 0.5964 for the air–biomass equivalence ratio, and 0.5881 for the CO2 mass flow splitting fraction. Finally, for the optimal system, the thermal efficiency is 38.8%, and the exergetic efficiency is 30.9%.

Using polygeneration systems is one of the most cost-effective ways for energy efficiency improvement, which secures sustainable energy development and reduces environmental impacts. This paper investigates a polygeneration system powered by low- to medium-grade waste heat and using CO2 as a working fluid to simultaneously produce electric power, refrigeration, and heating capacities. The system is simulated in Aspen HYSYS® and evaluated by applying advanced exergy-based methods. With the split of exergy destruction and investment cost into avoidable and unavoidable parts, the avoidable part reveals the real improvement potential and priority of each component. Subsequently, an exergoeconomic graphical optimization is implemented at the component level to improve the system performance further. Optimization results and an engineering solution considering technical limitations are proposed. Compared to the base case, the system exergetic efficiency was improved by 15.4% and the average product cost was reduced by 7.1%; while the engineering solution shows an increase of 11.3% in system exergetic efficiency and a decrease of 8.5% in the average product cost.

Reduction or elimination of reliance on traditional fossil fuels and of the emission of greenhouse gases and pollutants into the environment are affecting energy technologies, systems, and applications. In this context, one potential approach to achieving sustainability, decarbonization, and ensuring the energy and economic viability of existing and future energy systems involves adopting one or more renewable sources. The presented paper concentrates on examining the performance of a small-scale hybrid renewable polygeneration system. This system utilizes biogas produced through anaerobic digestion, which is then supplied to an internal combustion engine, along with solar energy converted into electrical energy by photovoltaic modules and wind energy harnessed through a wind turbine. A small-scale user, represented by residential buildings and a zootechnical farm with heating, cooling, and electrical energy demands, serves as the case study. TRNSYS software is employed to design and model the system, considering realistic assumptions about technical aspects and user energy requirements. The investigation involves analyzing the system's operation, considering both energy and economic perspectives. The paper discusses the pros and cons of combining biogas, solar, and wind energy in the proposed hybrid system under the considered case study. Despite non-satisfactory economic profitability without incentives, the proposed system allows one to save significant amounts of primary energy and carbon dioxide equivalent emissions. [ABSTRACT FROM AUTHOR]

Modern requirements for the production of hydrogen with a minimum carbon footprint, the possibility of using polygenerating systems for production of electricity, heat, or useful products, and chemical-looping technologies for producing hydrogen combined with capture of carbon dioxide are considered. A new system has been developed that integrates the use of biomass as a fuel, chemical looping, and syngas production in a polygenerating system of interconnected reactors, which is very promising in maximizing the effectiveness of hydrogen production without a carbon footprint (or with a negative carbon footprint). A procedure and results of calculations of the composition and consumption of generator gas, material balance of a chemical looping system, heat values of chemical reactions in a system of interconnected reactors, heat balance and temperatures in individual reactors, and heat and material balances in exhaust gas heat recovery units are presented. The effect of the main operating conditions of a chemical looping system on temperatures in the reactors was determined on the basis of the calculated and material balances. The calculated efficiency in terms of hydrogen production (75.93%) is given. This value fits well into the broad outline of the results obtained in simulation of similar systems for chemical looping hydrogen production from metal oxides and can be considered as a guideline when developing engineering solutions within the scope of the proposed process flow diagram. Potential directions of further studies are set. [ABSTRACT FROM AUTHOR]

A polygeneration system for power, heat, and refrigeration has been evaluated and optimized using exergy-based methods. CO2 is the working fluid. The study considered two environmental conditions for the potential implementation of the polygeneration system: cold (Casecold) and hot (Casehot). Aspen HYSYS® was used to perform steady-state simulations, Python was used for the automation of the process, and the connection of Aspen HYSYS® with Python was successfully applied for single-objective and multi-objective optimizations. A wide range of decision variables was implemented. The minimization of the average cost of a product per unit of exergy was the goal of single-objective optimization and was included in the multi-objective optimization in addition to the maximization of the overall exergy efficiency. Single-objective and multi-objective optimization were applied. Both optimization algorithms result in the necessity to increase the pinch temperature in the heat exchanger (ΔTpinch,HE), maintain the pinch temperature in the gas cooler (ΔTpinch,GC), and augment this value for the evaporator (ΔTpinch,EVAP). Notably, higher isentropic efficiency for turbomachinery correlates with improved optimization outcomes. These findings contribute to the applicability and performance of the polygeneration system, offering potential advancements in sustainable energy solutions. [ABSTRACT FROM AUTHOR]

Biogas fuel has gained recognition as a highly suitable alternative to fossil fuels, attributed to its renewable nature and remarkable energy density. Biogas fuel utilization facilitates the integration of combined energy systems equipped with multi-generational structures, rendering them suitable for long-term planning and management. Hence, this study presents a unique approach to using biogas for multigeneration, exhibiting enhanced thermodynamic efficiencies and negative carbon dioxide emissions. To achieve the stated objective, an innovative system is devised that involves the utilization of a biogas separation unit in integration with several other components, including a LNG cold energy utilization unit, an ammonia Rankine cycle, a desalination unit, a Kalina cycle, a solid oxide electrolyzer cell, a biomethane combined cycle, and a methanol synthesis unit. The newly devised configuration is simulated through the Aspen HYSYS software and assessed from energy, exergy, environmental, and economic considerations. Based on the research findings, the suggested methodology exhibits energy and exergy efficiencies of 91% and 83%, correspondingly. Furthermore, the evaluation of the entire unit cost of the product and the levelized energy cost reveals values of 4.81 $/GJ and 0.033 $/kWh, respectively. The carbon dioxide emission intensity of the newly implemented process is calculated to be − 0.1041 kg/kWh. The economic aspects reveal a favorable net present value of 1470.6 M$ and a payback period of 5.29 years. [Display omitted] • Use of Aspen HYSYS for simulating a novel polygeneration process based on biogas. • Proposed structure uses biogas separation unit and LNG cold energy utilization unit. • Producing power, cooling, heat, fresh water, liquid CO 2 , biomethane, and methanol. • Exergy efficiency and total unit cost of product equal 83% and 81.4 $/GJ. • The net carbon dioxide emission intensity for the new process is − 0.1041 kg/kWh. [ABSTRACT FROM AUTHOR]

Transitioning from fossil fuels to renewable energy ensures a sustainable and green future by limiting greenhouse gas emissions and their nuisance effects. This study proposes a polygeneration system that harnesses renewable energy to produce multiple energy vectors simultaneously and equipped with storage to mitigate the impact of intermittent weather. To perform dynamic analysis, proposed system has been modeled, optimized, and simulated using the transient simulation software TRNSYS®. The designed model has been optimized in GenOpt, linked with TrnOpt, under the weather conditions of Gujrat, Pakistan. The power system is energized by solar photovoltaic, thermal and wind power to produce cooling, heating, electricity, hydrogen, and oxygen as energy vectors, and also provides electric, hydrogen, and thermal storage. Prime movers utilized for energy conversion consists of evacuated glass tube collector, photovoltaic panels, wind energy conversion system, fuel cell, electrolyzer, and absorption chiller, which facilitate air-conditioning, space and water heating, electric power supply for electric vehicle, building load & national grid, hydrogen for internal combustion engines, fuel cell electric vehicle and industrial applications, as well as oxygen for hospitals. The study has shown that thermal collector has 68% efficiency, a solar fraction 0.78, peak outlet temperature 143.77 °C, and generates a total 1399656.25 kJ thermal energy. The wind and photovoltaic systems have maximum efficiencies values 52.24 % and 10.90 % respectively, resulting in the production of 44.8 MWh electric energy. Embracing the synergy of solar and wind power in a polygeneration system holds the key to a sustainable and eco-friendly future.

Schemes of polygeneration plants based on carbon dioxide are presented, in which the energy source are secondary energy resources and a gas turbine plant. These polygeneration schemes make it possible to simultaneously produce electricity, heat, cold, carbon dioxide in liquid and gaseous aggregate state, as well as to dispose of part of the carbon dioxide emitted into the atmosphere, due to its absorption from combustion products and use for commercial and technological purposes. The structure of the mathematical model of the program that has been developed for the exergetic analysis of polygeneration schemes is presented. With the help of the program, an exergetic analysis of polygeneration schemes was performed, in which polygeneration turbine units with different parameters of carbon dioxide in front of the turbine, as well as single and double overheating of carbon dioxide were compared. The exergetic electrical efficiency of polygeneration plants as a whole and its individual elements were taken as the criteria to be compared. Polygeneration plants with double overheating and supercritical parameters of carbon dioxide in front of the turbine have the greatest efficiency. A method for calculating of the economic indicators of polygeneration schemes is presented, which makes it possible to take into account the influence of double overheating and carbon dioxide parameters in the cost of a polygeneration plant. The economic efficiency indicators of various versions of polygeneration schemes, such as the internal rate of return, net discounted income, static and dynamic payback periods are obtained. It has been established that all variants of polygeneration schemes have acceptable indicators of economic efficiency, the static payback period of the proposed polygeneration schemes does not exceed 5 years, while the internal rate of return does not decrease by less than 22,8%.

This work experimentally investigates the fuel-rich combustion of CH 4 /CO 2 /O 2 mixtures in a piston engine. The focus of the experiments is to determine suitable operating parameters in terms of stable engine operation, syngas production, CO 2 conversion, and avoiding soot emissions. In particular, the spark timing, CO 2 intake mole fraction, equivalence ratio, and compression ratio were varied. Results show stable spark-ignition operation over a wide range of the investigated parameters at a compression ratio of 10. Acceptable operation could be achieved within the spark timing limits of -38° to 10 °CA after top dead center, 7 to 27% CO 2 in the inlet and equivalence ratios from 2 to 2.5. A maximum H 2 yield of 62% could be achieved at an equivalence ratio of 1.9 and a CO 2 intake mole fraction of 4% at a compression ratio of 4.5. Spark time advancing from -10 to -38 °CA enhanced the dry reforming reaction and increased the hydrogen yield per methane from 38 to 45%. A significant influence of compression ratio on the amount of soot in the product gas was observed, showing that higher compression ratios increase soot formation. [ABSTRACT FROM AUTHOR]

This paper reviews the fundamentals of the thermoeconomic diagnosis theory. Thermoeconomic diagnosis is one of the main applications of the exergy cost theory used to identify the causes of additional resource consumption of a system due to inefficiencies in its components, published in the late 1990s. Thermoeconomic diagnosis has usually been applied to diagnose power plants with high consumption of fossil fuels and fixed production. However, it does not consider the final production and waste generation variation. In this paper, Circular Thermoeconomics is applied to analyze in depth the effect of malfunctions on additional waste generation and changes in the final output of the system. This new formulation can be applied to polygeneration systems, where there is a simultaneous variation of final products, and to process integration and industrial symbiosis, where a part of the waste generated by a plant could be reused in other processes or plants. [ABSTRACT FROM AUTHOR]

In this paper, the experimental results of the thermal sub-system of a reliable and cost-effective polygeneration solar system are presented. This polygeneration system produces heating, cooling, and electricity from solar energy, which is used in an existing test building. Heat is generated in four evacuated tube solar collectors (ETCs). The heat may be used for space cooling through a variable geometry ejector (VGE) heat pump. In order to reduce the mismatches between generation and consumption, two thermal storage tanks were added. The performance of a new thermal storage, with 400 L, able to store both sensible and latent heat, was tested. The heating performances of the test building were assessed. Ejector cycle tests were also performed, and the variation of the cooling coefficient of performance (COP) was calculated for different flow rates. For heating, the results showed that the heat storage was capable of heating the test building for 8 h, with temperatures between 22 °C and 26 °C. All results showed that this polygeneration prototype could be capable of meeting the heating and cooling needs when applied to a real building.

It has been demonstrated that energy systems driven by conventional energy sources like fossil fuels are one of the main causes of climate change. Organic Rankine cycles can help to reduce that impact, as they can be operated by using the industrial waste heat of renewable energies. The present study presents a comprehensive bibliographic review of organic Rankine cycles. The study not only actualizes previous reviews that mainly focused on basic cycles operating on subcritical or supercritical conditions, but also includes the analysis of novel cycles such as two-stage and hybrid cycles and the used fluids. Recuperative and regenerative cycles are more efficient than reheated and basic single-stage cycles. The use of two-stage cycles makes it possible to achieve higher thermal efficiencies and net power outputs of up to 20% and 44%, respectively, compared with those obtained with single-stage cycles. Theoretical studies show that hybrid systems, including Brayton and organic Rankine cycles, are the most efficient; however, they require very high temperatures to operate. Most organic Rankine cycle plants produce net power outputs from 1 kW up to several tens of kW, mainly using microturbines and plate heat exchangers. [ABSTRACT FROM AUTHOR]

A gasification plant may partially replace an industrial thermal plant and hydrogen production plant by polygenerating valuable products (hydrogen, power, steam) from low-value materials. Carbon energy analysis is one way of conceptually evaluating such processes. In this paper, the integration of a heavy residue (HR) gasification plant into a mid-size oil refinery (5 million t per year crude processing rate) is conceptually assessed via the comparison of electricity, natural gas and heavy residue consumption, and CO2 emissions. The main purpose of the integration is to reduce the consumption of natural gas currently used for hydrogen production at the expense of increased HR consumption and to achieve a reduction in CO2 emissions. Two case studies with different modes of operation were compared to base case showing that annual reduction of 2280 GWh in natural gas consumption with constant heat and hydrogen production is possible, accompanied with a slight increase in electricity purchase by 28 GWh per year. HR processing in the refinery increases by over 2800 GWh per year. The refinery's CO2 emissions increase by more than 20% (up to 350 kt per year) as a result, while, after incorporating external emissions into the balance, a decrease of more than 460 kt CO2 per year can be achieved. This confirms that the integration of gasification plants within industrial enterprises and clusters has a positive environmental and energy impact and supports the idea of converting low-value material to more valuable products in polygeneration plants. The economics of HR gasifier integration in varying operations under real refinery conditions remain to be explored. [ABSTRACT FROM AUTHOR]

Due to the increasing importance of cooling applications, geothermal trigeneration systems might be of high interest in the future. This work aims at evaluating different plant layouts against the background of more advanced plant configurations and part load behaviour. Five different plant configurations are analysed for geothermal heat source temperatures between 110 and 150 °C. The highest net power output is achieved by an advanced serial-parallel configuration (ASPC), but in case of high heating and cooling demand, a standard serial-parallel configuration is more favourable. For the considered base demand scenario of 130 °C, the ASPC results in an annual net power generation of 20.94 GWh, which is 6.9% higher than the second favourable configuration. The application of a recuperator within the ORC system has a significant impact on the serial concepts, but only marginally increases the power output of the parallel layouts. Comparing two exergetic efficiencies highlights that the assumed definition can result in a different ranking of the plant layouts. Considering the exergy that is transferred from the brine to the trigeneration system reveals the highest exergetic efficiency for a serial configuration, while the focus on the available exergy flow reveals the highest efficiency for the ASPC layout. Considering a brine temperature of 130 °C results in a maximal achievable second law efficiency of 34.1% if evaluating the available exergy flow. The evaluation of the pay-back period reveals that the ASPC results in the shortest pay-back period of 13.8 years. • Investigation of several plant configurations considering part-load operation. • Highest net power output is achieved by an advanced serial-parallel configuration. • For each plant configuration, there is an optimal desorber temperature of the AC. • A pay-back period of 14 years can be achieved. [ABSTRACT FROM AUTHOR]

Flash-based geothermal cycles correspond to environmentally friendly and cost-effective processes in a renewable framework and provide an opportunity for combined cycles. However, these cycles are characterized by significant energy losses and their waste stream's low/medium operational temperature is the principal defect for managing multiple generation arrangements without assisting other energy resources. Hence, the main aim of this study is to propose a novel polygeneration scheme, integrated with a dual-flash geothermal cycle equipped with self-superheaters, able to mitigate the discussed defect. A new coupled series and parallel design of energy recovery is established, allowing to increase the compatibility of combined cycles and enable a larger production. This design encompasses a single-effect refrigeration cycle, a modified transcritical CO 2 cycle, a polymer electrolyte membrane electrolyzer, and a thermal desalination cycle. The proposed process is examined from thermodynamic, sustainability, and economic (exergoeconomic and net present value analyses) points of view. Besides, a detailed sensitivity study is conducted by which the trend of performance variables in response to the increasing five main decision parameters is viewed. Afterward, an intelligent approach relying on an artificial neural network is built to learn and validate the behavior of defined objective functions (exergetic efficiency and products' levelized cost). Moreover, a multi-objective grey wolf optimization (MOGWO) procedure endeavors to optimize the operation of the system. According to the results of this study, flash tank 2′s inlet pressure is the effective parameter, and its mean sensitivity index equals 0.289. Besides, the aforementioned objectives are gauged at 37.45% and 0.0625 $/kWh, respectively. [ABSTRACT FROM AUTHOR]

In the context of the energy transition, efficient energy systems are desired. One promising approach is the use of piston engines for energy and species conversion. Before such processes are in fact realized, they are studied using simulations so that their capabilities can be identified. To optimize corresponding processes regarding polygeneration and exergy storage, it is necessary to analyze a large number of process parameters fast and reliably.In this work, we extend an adjoint-based approach for the sensitivity analysis of homogeneous reactors by a piston engine model and apply it for the optimization of H2 and C2H4 production by modification of initial conditions and additives. The approach reliably delivers good results for representative configurations. It was found that the optimum equivalence ratio for H2 production in piston engines ranges from 2.33–2.86, depending on which additives may be added, leading to H2 yields up to 80%. For C2H4 optimization, pyrolysis reactions get more important, leading to very fuel-rich conditions with an equivalence ratio of 6.2 to 7.2. C2H4 yields up to 12% are achieved. To evaluate these conditions thermodynamically, an exergetic analysis was carried out, revealing exergetic efficiencies up to 88% and 95%, respectively, if the unconverted fuel is recirculated. In addition, the approach provides time-dependent information on all process parameters, including mixture and engine parameters, which can be used to develop alternative processes and performance strategies.

Reduction or elimination of reliance on traditional fossil fuels and of the emission of greenhouse gases and pollutants into the environment are affecting energy technologies, systems, and applications. In this context, one potential approach to achieving sustainability, decarbonization, and ensuring the energy and economic viability of existing and future energy systems involves adopting one or more renewable sources. The presented paper concentrates on examining the performance of a small-scale hybrid renewable polygeneration system. This system utilizes biogas produced through anaerobic digestion, which is then supplied to an internal combustion engine, along with solar energy converted into electrical energy by photovoltaic modules and wind energy harnessed through a wind turbine. A small-scale user, represented by residential buildings and a zootechnical farm with heating, cooling, and electrical energy demands, serves as the case study. TRNSYS software is employed to design and model the system, considering realistic assumptions about technical aspects and user energy requirements. The investigation involves analyzing the system’s operation, considering both energy and economic perspectives. The paper discusses the pros and cons of combining biogas, solar, and wind energy in the proposed hybrid system under the considered case study. Despite non-satisfactory economic profitability without incentives, the proposed system allows one to save significant amounts of primary energy and carbon dioxide equivalent emissions.

A polygeneration system for power, heat, and refrigeration has been evaluated and optimized using exergy-based methods. CO2 is the working fluid. The study considered two environmental conditions for the potential implementation of the polygeneration system: cold (Casecold) and hot (Casehot). Aspen HYSYS® was used to perform steady-state simulations, Python was used for the automation of the process, and the connection of Aspen HYSYS® with Python was successfully applied for single-objective and multi-objective optimizations. A wide range of decision variables was implemented. The minimization of the average cost of a product per unit of exergy was the goal of single-objective optimization and was included in the multi-objective optimization in addition to the maximization of the overall exergy efficiency. Single-objective and multi-objective optimization were applied. Both optimization algorithms result in the necessity to increase the pinch temperature in the heat exchanger (ΔTpinch,HE), maintain the pinch temperature in the gas cooler (ΔTpinch,GC), and augment this value for the evaporator (ΔTpinch,EVAP). Notably, higher isentropic efficiency for turbomachinery correlates with improved optimization outcomes. These findings contribute to the applicability and performance of the polygeneration system, offering potential advancements in sustainable energy solutions.

In this study, an integrated hybrid polygeneration system based on solar and biogas energy is developed for simultaneous heat and power generation and hydrogen production. A heat recovery system is employed, which can recover the waste heat from the flue gas for effective utilisation in the steam network. The devised system, comprising solar, biogas, chemical, steam, and power islands, is investigated and comparatively evaluated through energy and exergy approaches. Additionally, an optimisation study is carried out to find the optimal exergy efficiency. The findings suggest that integrating the steam island and hybrid system improved the overall system performance significantly. The optimisation results demonstrate the value of 58.06% for exergy efficiency, while energy efficiency is also increased from 60.55% to 65.94%.

Piston engines can be operated with very fuel-rich fuel/air mixtures to simultaneously produce syngas, power, and heat – so-called “polygeneration”. In this context, the effects of methoxymethane (dimethyl ether, DME), ethoxyethane (diethyl ether, DEE), and n-heptane as additives in compression-ignition of fuel-rich methane/air mixtures were investigated in experiment and simulation. The experiments were performed in a single-cylinder octane-number test engine at a compression ratio of 10. Engine operating stability, auto-ignition behavior, and syngas production were examined. The simulations used a single zone model with detailed chemical kinetics. The method for pressure trace analysis was adapted to the very fuel-rich conditions examined in this study. The choice of additive does not significantly influence syngas production, but a distinct influence on auto-ignition was found. The most effective additive in terms of mass fraction was DEE which produced stable operation at around 20% by weight. While the use of DME and n-heptane resulted in similar heat release traces, DEE yielded more early heat release and less of a negative temperature coefficient (NTC) behavior. The widest stable operating range in terms of additive fraction was found for DME. A reaction path analysis showed that the effect on ignition is similar for all three additives: they react early in the compression stroke and lead to H-abstraction from CH4. Comparing heat release rates and calculated cylinder temperatures indicated that not only the additive's reactivity but also its heat capacity contributes to auto-ignition behavior.

Hydrogen is one of the most important base chemicals and discussed as a future energy carrier for power and heat generation, as well as energy storage. Producing hydrogen at low costs and low CO2 emissions is thus of increasing importance. This study addresses the thermodynamics and economics of hydrogen, power, and heat generation by partial oxidation of methane in fuel-rich operated homogeneous charge compression ignition (HCCI) engines. Therefore, a python model of two different process concepts with different hydrogen separation technologies was developed and analyzed: pressure swing adsorption (PSA) and palladium membrane separation. The operating conditions of the engine and the separation were evaluated by conducting a global sensitivity analysis. The most suitable engine operating parameters were found at an equivalence ratio of 2, an intake temperature of 200 °C, a rotational speed of 1500 1/min, and a compression ratio of 22. In direct comparison, PSA consistently yielded better results than the palladium membrane, and low feed pressures were favorable. Subsequently, the uncertainty of economic input values was investigated and the power and hydrogen costs evaluated. In the PSA case, the electricity and hydrogen costs were found in a range of 44.2 €/MWh to 97.6 €/MWh and 2.7 €/kg to 7.2 €/kg, respectively, with an overall exergetic efficiency of 68.3%. Therefore, the proposed polygeneration system provides electricity at competitive costs and hydrogen at costs similar to a small-scale steam reforming plant at comparable efficiencies. Further scaling up of the engine could provide hydrogen at the cost of large-scale steam reforming, making the proposed concept a promising alternative.

To address current challenges related to climate change, novel concepts, such as engine-based polygeneration under fuel-rich conditions, have recently been developed. In this context, understanding and validation of the associated chemical kinetics are a key factor for prediction and optimizations. In this work, the combined effect of ozone and DME as additives on the partial oxidation of natural gas mixtures is investigated in a plug-flow reactor at a pressure of 4 bar and at temperatures ranging from 373 to 973 K. Double-imaging photoelectron photoion coincidence (i2PEPICO) spectroscopy measurements are presented to study the conversion of the reactants and the formation of main products, and to identify important intermediates responsible for the low temperature chemistry phenomena and ignition characteristics of the natural gas/dimethyl ether/ozone mixture. Among the activation effect of ozone, the temperature-variant ozone dissociation at elevated pressures up to 20 bar is studied for the first time, revealing the start of ozone decomposition at 423 K in the investigated pressure range. In addition, the ozone decomposition is shown to be slightly pressure-dependent in the pressure range between 1 and 20 bar with lower ozone conversions at higher pressures. The experimental results are compared with model predictions using literature reaction mechanisms for validation and further analysis. The ozone decomposition initiates fuel conversion and the formation of oxygenates and hydroperoxides at very low temperatures, i.e., 423 K, resulting in an overall three-stage oxidation process at ∼450 K (1. stage), ∼550 K (2. stage), and ∼750 K (3. stage). Also, the overall fuel conversion is enhanced in the intermediate temperature range (between 550 K and 750 K) by up to 40%-points. The hydroperoxides, among other species, are clearly identified by mass-selected threshold photoelectron spectra from the literature. Excellent agreement between experiments and simulations is found, while deviations are observed for some oxygenates at very low temperatures showing the need for further model improvements.

A palm oil-based polygeneration system (POPS), which is a combination of a fixed bed hydrotreating reactor (FBHTR), a three-phase separator, and a series of cryogenic separators, is co-production process of green diesel and liquefied petroleum gas (LPG) named Design 1. The FBHTR model is validated by experiment data and its optimal operating parameters are determined by solving the response surface methodology-based optimization algorithm. Two CO 2 -negative designs for the POPS named Designs 2 and 3 adopt approaches of (i) the evacuated tube solar collector (ETSC) for reducing 35% flue gas from the furnace, (ii) the amine-based CO 2 capture process coupling with pre- or post-separation system for producing the high-purity CO 2 product, and (iii) the heat integration design for reducing the energy duties of hot/cold utilities. Design 2 is validated to achieve the maximum negative net CO 2 emissions. Design 3 not only ensures the negative net CO 2 emissions, but also it produces three high-purity products (98.3% green diesel, 100% LPG, and 99.9% CO 2) simultaneously. [Display omitted] [ABSTRACT FROM AUTHOR]

The integration of solar energy systems is crucial to achieving the global goals for sustainability as well as the reduction of greenhouse gases and pollutants emissions. In this direction, the development of multigeneration systems is very important as they can cover the increasing and numerous demands of modern society in a high-efficient way. In parallel, hydrogen is a promising alternative fuel that has gained attention recently because it can substitute conventional energy sources. So, the objective of the present work is the review, classification, discussion, and comparison of solar-driven multigeneration systems that include hydrogen production. This study is a novel one because it is focused on the integration of hydrogen generation methods into polygeneration systems, while existing publications present the useful outputs of the units, without specialization. In parallel, it meets the increasing need for the investigation of hydrogen energy potential. Apart from hydrogen, other common useful outputs are electricity, heating, cooling, domestic hot water, and freshwater. In this work, the plants are classified according to the hydrogen production method. In parallel, different types of solar devices, such as thermal collectors, photovoltaics, and thermal photovoltaics as well as other additional energy sources are also examined. So, numerous configurations are investigated comprehensively, which can produce a plethora of useful outputs, as well as include thermodynamic cycles, such as Rankine cycles, organic Rankine cycles, and other devices, such as absorption chillers, or desalination units. All the units are evaluated and compared in terms of energy, and exergy performance as well as economic viability, and hydrogen production rate. In general, solar tower-based and parabolic trough collector-based units are high-efficient energetically and exergetically, while concentrating photovoltaic thermal plants achieve high energy efficiency. Finally, suggestions for future research and development are made. • Solar-driven multigeneration systems with hydrogen production are investigated. • The systems are mainly classified according to the hydrogen generation methods. • Solar collectors, photovoltaics, and hybrid solar devices are examined. • Hybridization with auxiliary energy sources is also presented. • Solar towers, PTC, and CPVT are the most efficient systems. [ABSTRACT FROM AUTHOR]

In line with the decarbonization of the domestic sector to meet the 2050 climate neutrality targets, this paper describes the energy, economic, and environmental analysis of a set of different novel configurations of polygeneration installations to provide electricity, air conditioning, domestic hot water, and desalinated water for a building of 80 dwellings. All arrangements were designed to cover 100% of the five demands required in the building with renewable energy only, from photovoltaic (PV) and photovoltaic-thermal (PVT) panels and biomass backup boilers (BB). Electricity can be sold to or purchased from the grid without electrical storage with batteries. Additional electricity generation with thermoelectric generators (TEG) coupled to the PVTs, and the BB was explicitly analyzed. The choice of electrically or thermally activated technologies (heat pump, HP/single-effect absorption chiller, SEAC for cooling and multi-effect distillation, MED/reverse osmosis, RO for desalination) created four configurations from the basic structure based on solar and biomass sources. Thus, the paper has studied four designs in detail and applied them to three case studies corresponding to different locations in Spain. They were modeled with TRNSYS and included specific models for desalination technologies. Both structures provide important energy and CO2 savings concerning the conventional supply of the building demands. The novel life-cycle analysis approach further increases the lifetime CO2 savings for all configurations as well. The electric option (the combination of HP and RO for cooling and desalting) was, by far, the most attractive solution in terms of liability and lower investment required in the three case studies. [ABSTRACT FROM AUTHOR]

Besides satisfying the energy demands of buildings, distributed generation can contribute toward environmental conservation. However, determining the best configuration and operational strategy for these systems is a complex task due to the available technology options and the dynamic operating conditions of buildings and their surroundings. This work addressed the synthesis and optimization of an energy system for a commercial building (hotel). Electricity, hot water, and cooling demands were established for a hotel located in Northeast Brazil. The optimization problem was based on mixed-integer linear programming and included conventional equipment, solar energy resource (photovoltaic and thermal technologies), and biomass. The objective function of the optimization was to minimize annual economic costs, which involved considering the capital and operation costs. A reference system was established for comparison purposes, where energy demands were met conventionally (without cogeneration or renewable energy), whose annual cost was BRL 80,799. Although the optimal solution did not rely on cogeneration, it benefited from the high degree of energy integration and had a total annual cost of BRL 24,358 (70% lower). The optimal solution suggested the installation of 70 photovoltaic panels and used biomass (sugarcane bagasse) to operate a hot water boiler. Solar collectors for hot water production were not part of the optimal solution. Sensitivity analyses were also carried out, varying the electricity and natural gas tariffs, and the type of biomass employed, but the configuration of the system did not change compared with the optimal economic solution. [ABSTRACT FROM AUTHOR]

The energy sector is nowadays facing new challenges, mainly in the form of a massive shifting towards renewable energy sources as an alternative to fossil fuels and a diffusion of the distributed generation paradigm, which involves the application of small-scale energy generation systems. In this scenario, systems adopting one or more renewable energy sources and capable of producing several forms of energy along with some useful substances, such as fresh water and hydrogen, are a particularly interesting solution. A hybrid polygeneration system based on renewable energy sources can overcome operation problems regarding energy systems where only one energy source is used (solar, wind, biomass) and allows one to use an all-in-one integrated systems in order to match the different loads of a utility. From the point of view of scientific literature, medium- and large-scale systems are the most investigated; nevertheless, more and more attention has also started to be given to small-scale layouts and applications. The growing diffusion of distributed generation applications along with the interest in multipurpose energy systems based on renewables and capable of matching different energy demands create the necessity of developing an overview on the topic of small-scale hybrid and polygeneration systems. Therefore, this paper provides a comprehensive review of the technology, operation, performance, and economical aspects of hybrid and polygeneration renewable energy systems in small-scale applications. In particular, the review presents the technologies used for energy generation from renewables and the ones that may be adopted for energy storage. A significant focus is also given to the adoption of renewable energy sources in hybrid and polygeneration systems, designs/modeling approaches and tools, and main methodologies of assessment. The review shows that investigations on the proposed topic have significant potential for expansion from the point of view of system configuration, hybridization, and applications. [ABSTRACT FROM AUTHOR]

• • Unconventional methane-containing gaseous fuel resources are the most feasible substitute energy. • • Unconventional methane-containing gaseous fuel resources can be used as fuels and chemical materials. • • Unconventional methane-containing gaseous fuel resources can be used in polygeneration system. • • Commercial application of unconventional methane-containing gaseous fuel resources is desirable but problematic in reality. Due to long term extraction and use, conventional methane-containing gaseous fuel resources are decreasing gradually. Therefore, the development and utilization of unconventional methane-containing gaseous fuel resources are extremely important. This article mainly summarizes the current reserves, high-value development and utilization technologies of unconventional methane-containing gaseous fuel resources, such as shale gas, coalbed methane, and coke oven gas, etc. Researchers have found that currently only high concentration coalbed methane and coke oven gas are widely used in power generation as fuel, while other unconventional methane-containing gaseous fuel resources are still in the research stage due to their complex compositions or complicated application systems. Although partial oxidation and steam reforming technologies are widely used in the production of syngas from methane-containing gaseous fuel resources, the development for further synthesis of chemical products are relatively slow. Polygeneration processes of these unconventional methane-containing gaseous fuel resources involve a wide range of technologies, and the subsystems may not be mature yet, which limit their developments. However, the "stationary gas power plant" can achieve on-site conversion of shale gas into electricity, while low concentration coalbed methane can be used for power generation through solid oxide fuel cells. Chemical looping reforming of unconventional methane-containing gaseous fuel to produce syngas is expected to achieve high CH 4 conversion rate and maximum CO 2 utilization rate. By studying the high-value development and utilization technologies of unconventional methane-containing gaseous fuel resources, the current pressure on conventional gaseous fuel resources can be alleviated, and multi-level energy utilization can be achieved, which is helpful for providing references for the current and future development of the unconventional methane-containing gaseous fuel resources industries. [ABSTRACT FROM AUTHOR]

In this study, a new environmentally friendly polygeneration scheme is proposed in arrangement with a gas turbine cycle. In order to investigate the proposed system, parametric research is conducted in conjunction with the energy, exergy, economic, and environmental assessments (4E study). The simulation is done in the Aspen HYSYS software. According to the design condition results, the total energy efficiency and exergy efficiency, thermoeconomic indicators such as total unit cost of product and total product cost, as well as the waste heat recovery ratio in the heat exchanger network of the evaporator, are 57.81 %, 63.47 %, 25.12 $ / GJ , 0.1019 $ / kWh , and 49.67 %, respectively. In addition, it is determined that the total exergy destruction rate and the exergy destruction intensity for the proposed process are 204470 kW and 1.33 kW D / KW P , respectively. The gas turbine cycle with a share of 60 %, exhibits the highest irreversibility. Based on economic estimates, the project requires a total investment of $636209804. In addition, considering an annual income of 159850224 $, the payback period is 3.98 years. Lastly, the environmental evaluation indicates that the proposed process has a carbon footprint equal to 0.356 kg C O 2 / kW h and a total carbon dioxide emission of 67241.36 kg/h. • An environmentally friendly polygeneration process integrated with a gas turbine cycle. • Producing electricity, hydrogen, oxygen, hot water, chilled water, and fresh water. • Simulation based on the Aspen HYSYS software and 4E study. • Energy and exergy efficiencies and payback period are 57.81 %, 63.47 %, and 3.98 years. • Total CO 2 emission and a CO 2 footprint are 67241.36 kg / h and 0.356 Kg C O 2 / kW h. [ABSTRACT FROM AUTHOR]

The lack of access to electricity and clean water still affects a substantial proportion of rural areas worldwide, in particular the global south. This paper presents a sustainable polygeneration system that can provide electricity, heat, and drinking water by using agricultural residues in remote rural areas. This polygeneration system consists of a solid biomass-fueled Brayton-Stirling combined cycle system, a boiler, and an air-gap membrane distillation unit. Four different system operation modes were designed to examine the most ideal configurations for maximizing power output, overall efficiency, and/or clean water production, considering a polygeneration system designed for a rural village with daily demands of 13450 kWh electricity and 7.5 m3 drinking water. A thermodynamic analysis are employed to analyze and compare these modes, each operating under steady state conditions. The highest electricity output, up to 160 kW, while the highest clean water is up to 0.7 m3/h. The fuel consumption can reach 0.9 kWh/kg of solid fuel and provide up to 0.0045 m3 of freshwater. In addition, nonlinear multi-objective optimization is used to meet the power demands of typical day in rural areas by varying the polygeneration operation modes and turbine inlet temperature. [Display omitted] • A solid bio-fuel based polygeneration system is developed for a rural village. • It consists of a Brayton-Stirling cycle, a boiler and a membrane distillation unit. • A thermodynamic study is conducted for comparing four designed operation modes. • Flexible operation can be achieved by combining the four operation modes. • The system can provide 1359 kWh electricity and 7.5 m3 clean water per day. [ABSTRACT FROM AUTHOR]

This study presents the generation of an integrated resource network that encompasses a bioenergy supply chain and a polygeneration hub. The resource network is designed using a superstructure that comprises 3 layers. The first layer is a supply chain network of seasonally available renewable and non-renewable energy sources and is connected to the second layer by a transport system comprised of rail, road, and pipeline. The second layer, which is the polygeneration hub, comprises a boiler to produce high-pressure steam, steam turbines for generating power, a multi-effect evaporation system for desalinating salt-water and an absorption refrigeration system to produce chilled water. The option of connecting the boiler to a solar-thermal and heat storage subnetwork for feedwater pre-heating is included in the second layer. Piping and electrical cables connect the polygeneration layer to the third layer, which comprises industrial heat demand, represented by heat exchanger network, and electrical power demand. The model is applied to a case study in which the subnetworks in the overall integrated superstructure layers are considered as individual players in an industrial symbioses network with the possibility to be in a cooperative game. The objective function of the model, which is represented as a mixed integer nonlinear programming model, involves the minimization of the summation of the players' marginal contribution, with equal weighting applied for each player, to the coalition's total annual cost. The result obtained involves preference for a coalition among participating subnetworks that include combined heat and power, multi-effect evaporation, and heat exchanger network. • Synthesis method for integrated resource supply chain and polygeneration network is presented. • Polygeneration involves electricity, clean and chilled water, and different grades of steam levels. • Economically optimal coalitions among subnetworks are established using Shapley Values. [ABSTRACT FROM AUTHOR]

The correct management of renewable polygeneration systems is a highly effective approach that can not only help expand renewable energy systems but also ensure sustainable production. In the present work, a new procedure for designing renewable polygeneration systems is introduced. In this procedure, the management of polygeneration systems is discussed from various aspects, including climatic change, techno-economic and environmental conditions, layout design, ecological sustainability, and the sociological approach to polygeneration systems in a practical form. As a case study, an innovative biomass-solar-wind polygeneration system to produce power, ammonia, and freshwater for Ahvaz in Iran was designed and evaluated according to the developed procedure. The integration of multi-effect distillation and humidification-dehumidification desalination has been employed for freshwater production. For ammonia production, syngas produced in the gasification unit and nitrogen obtained from the air separation unit were utilized. Power production has been achieved using a combination of the hydrogen-ammonia Brayton cycle, the supercritical carbon dioxide cycle, and the organic Rankine cycle. The designed system was evaluated using energy, exergy, exergoeconomic, exergoenvironmental, emergoeconomic, emergoenvironmental, carbon footprint, and water footprint analyses. The layout design of the proposed system and the sociological study of the system from a systemic approach have enhanced the visibility of its application. Additionally, the investigation of biomass fuel variations and combinations according to climate, along with optimization and dynamic analyses, are key measures that allow for a more comprehensive evaluation of the system from various management perspectives. The results show that the proposed system is capable of producing 523.34 m3/day freshwater, 10.1 MW of power, and storing 17.75 ton/day of ammonia in optimal state. The energy and exergy efficiency of the polygeneration system in the optimal state is 29.97% and 13.12%. The total cost rate and total environmental impact rate of the entire system in this case are equal to 0.48 $/s and 19.79 mPts/s, respectively. Meanwhile, the defined renewable system has an ecological sustainability index of 1.76. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper reviews the fundamentals of the thermoeconomic diagnosis theory. Thermoeconomic diagnosis is one of the main applications of the exergy cost theory used to identify the causes of additional resource consumption of a system due to inefficiencies in its components, published in the late 1990s. Thermoeconomic diagnosis has usually been applied to diagnose power plants with high consumption of fossil fuels and fixed production. However, it does not consider the final production and waste generation variation. In this paper, Circular Thermoeconomics is applied to analyze in depth the effect of malfunctions on additional waste generation and changes in the final output of the system. This new formulation can be applied to polygeneration systems, where there is a simultaneous variation of final products, and to process integration and industrial symbiosis, where a part of the waste generated by a plant could be reused in other processes or plants.

Rapid population growth coupled with urbanization and industrialization are some of the critical challenges of Indian energy sector. Simultaneously India's fossil fuel dominated power sector is a big source of carbon emission. Increasing renewable power is a mission of India. Government has also a mission for maximum rural electrification. India has widely varying geographical topography including high mountains and a long coastal line etc. Extending the Indian national grid to remote poor villages may not be techno-economically feasible. Instead introducing decentralized hybrid renewable power to remote poor villages of India may help inclusive growth. This study explores the feasibility of such options with a few case studies. Including some other energy utilities in addition to power may be an even better support to poor villagers. A few case studies on such efficient polygeneration are also included. [ABSTRACT FROM AUTHOR]

Solid oxide fuel cells are an emerging energy conversion technology suitable for high-temperature power generation with proper auxiliary heat. Combining SOFCs and polygeneration has produced practical applications for modern energy system designs. Even though many researchers have reviewed these systems' technologies, opportunities and challenges, reviews regarding the optimal strategy for designing and operating the systems are limited. Polygeneration is more complicated than any other energy generation type due to its ability to generate many types of energy from various prime movers. Moreover, integration with other applications, such as vehicle charging and fueling stations, increases the complication in making the system optimally serve the loads. This study elaborates on the energy planning and guidelines for designing a polygeneration system, especially for residential applications. The review of polygeneration technologies also aligns with the current research trend of developing green technology for modern and smart homes in residential areas. The proposed guideline is expected to solve the complication in other applications and technologies and design the polygeneration system optimally. [ABSTRACT FROM AUTHOR]