Environmental Impact Rate Research Articles

Feasibility assessment of Low-Carbon methanol production through 4E analysis of combined cycle power generation and carbon capture Integration

This study evaluates the feasibility of producing methanol without carbon emissions Using a comprehensive 4E (energy, exergy, economic, and environmental) approach. Our study focuses on a single methanol production system, analyzing its efficiency, sustainability, and potential as a clean fuel production method so that focusing on capturing carbon dioxide from combined cycle power generation and using the generated power to produce hydrogen through ion exchange electrolysis. The systems were simulated using Aspen Plus software, considering practical constraints to align with the capacity of existing power plants. The analysis revealed that the studied methanol production systems can produce 65.3 MW of power, with a net production power of 65.2 MW available for sale to the national grid. The annual methanol production, based on 8,000 operational hours, is 46,086 tons. The cost of methanol production is estimated at $556.69 per ton, and the environmental impact rate was calculated at 0.3726 units, with an exergy efficiency of 31.63 %. The study demonstrates that methanol can be produced efficiently using carbon capture from combined cycles, significantly reducing carbon dioxide emissions. The results suggest that while the system involves high-cost equipment, it effectively balances power generation and methanol production with a relatively low environmental impact. Future research could focus on advanced exergy analysis to identify and mitigate sources of exergy destruction, as well as optimizing carbon capture configurations and integrating solar thermal energy to enhance system sustainability further.

Designing and multi-objective optimization of a novel multigenerational system based on a geothermal energy resource from the perspective of 4E analysis

Over the past few years, a growing emphasis has been placed on providing sustainable energies to reduce carbon emissions and promote energy efficiency. This paper delved into energy, exergy, exergoeconomic, and exergoenvironmental investigation for a system that combines the Kalina cycle, a double-effect absorption chiller with a vapor compression refrigeration system coupled with an air handling unit driven by a geothermal renewable energy resource. This innovative system generated four distinct outputs: electricity, potable water, cooling load, and hot water. Key system performance variables, such as net power output, coefficient of performance, sum unit cost of the product, energy and exergy efficiencies, the temperature of supply air to the cold store, and potable water production in the base mode, are measured at 63.45 kW, 0.83, 56.74 $/GJ, 62.28 %, 45.67 %, 268.7 K and 20.82 lit/h, respectively. This research explored the impact of various parameters on the output variables, the exergy destruction and environmental impact rate of all components, and the net percent value of the proposed system. The multi-objective optimization significantly improved energy and exergy efficiencies by 6.83 % and 1.8 % from its base mode. Exergy and exergoenvironmental analysis revealed that the highest exergy destruction occurs in Re-injection, and the highest environmental impact rate associated with exergy belongs to the HPG component. Moreover, the geothermal section has the largest share of exergy destruction, approximately 58.5 % of the total exergy destruction of the system.

Development and comprehensive analyses of a hybrid solar–geothermal driven polygeneration system: Thermodynamic, exergoeconomic, and emergoenvironmental aspects

The present research proposed an innovative polygeneration system that uses solar, geothermal, and natural gas energy to produce power, heat, steam, and freshwater. The system consists of a proton exchange membrane fuel cell, an organic Rankine cycle, and a multi-effect thermal desalination system. The study included thermodynamic, exergy, exergoeconomic, exergoenvironmental, emergy-based exergoeconomic, and emergy-based exergoenvironmental factors in its comprehensive evaluation of the system. Results underscored the financial aspect of the organic Rankine cycle and cogeneration system, incurring costs of 0.4518 $/s and 1.054 $/s respectively, while also highlighting the system's capability to produce 6 kg/s of freshwater. The environmental impact rates were quantified for the organic Rankine cycle and cogeneration system at 0.1417 and 0.4814 pts/s respectively, situating the system within its ecological context. Further, the study detailed the total efficiency and net power output of the organic Rankine cycle and cogeneration system, ranging between 32.45–33.51% and 43.25–45.83% for efficiency, and 56956–56322 kW and 50174–51898 kW for net power output r espectively, showcasing the system's operational capacity. A parametric analysis was also integral to the study, examining the impact of key parameters on the functionality of the proposed system, thereby providing a nuanced understanding of the system's performance under varying operational scenarios.

Optimal 4E design and innovative R-curve approach for a gas-solar- biological waste polygeneration system for power, freshwater, and methanol production

BackgroundCogeneration power plants traditionally rely on fossil fuels to produce stable power and heat. However, increasing energy demand and population growth have intensified the emission of biological pollutants due to fossil fuel use. The Global Alliance on Health and Pollution advocates for integrating renewable energy sources to mitigate these issues. ObjectivesThis study aims to evaluate the integration of a solar-biomass polygeneration system with a hybrid solar-waste-fossil fuel cogeneration system. The goal is to analyze the system from technical, economic, and environmental perspectives, focusing on optimizing energy demand and minimizing environmental impact. MethodsTo assess energy demand and supply, the R-curve methodology was applied to the hybrid cogeneration system, with a specific focus on solar and biomass renewable energies. Various scenarios were analyzed, including total annual costs, pollutant emissions, water footprint, and overall environmental impact based on life cycle assessment. The study examined and compared the performance of three types of biomass waste (Municipal solid waste, mixed paper waste, and date palm waste). Multi-objective optimization was performed using artificial intelligence and machine learning techniques, employing four meta-heuristic algorithms. The conditions generated by each algorithm were analyzed and compared. ResultsMunicipal solid waste, being the most readily available fuel, provided the most favorable economic conditions for the system. Environmentally, municipal solid waste ranked in the middle compared to other fuels. Among the optimization algorithms, the Salps swarm algorithm proved to be the most efficient in terms of calculation time and system efficiency improvements. The optimization improved net power generation by 5.25 %, overall energy efficiency by 16.27 %, total cost rate by 10.19 %, and total environmental impact rate by 14.02 %. ConclusionThe integrated system's performance was analyzed across different climatic change throughout the year. The multi-objective Salps swarm algorithm optimization demonstrated significant benefits in enhancing system efficiency and reducing costs and environmental impacts.

Economic and Environmental Analyses of an Integrated Power and Hydrogen Production Systems Based on Solar Thermal Energy

This study introduces a novel hybrid solar–biomass cogeneration power plant that efficiently produces heat, electricity, carbon dioxide, and hydrogen using concentrated solar power and syngas from cotton stalk biomass. Detailed exergy-based thermodynamic, economic, and environmental analyses demonstrate that the optimized system achieves an exergy efficiency of 48.67% and an exergoeconomic factor of 80.65% and produces 51.5 MW of electricity, 23.3 MW of heat, and 8334.4 kg/h of hydrogen from 87,156.4 kg/h of biomass. The study explores four scenarios for green hydrogen production pathways, including chemical looping reforming and supercritical water gasification, highlighting significant improvements in levelized costs and the environmental impact compared with other solar-based hybrid systems. Systems 2 and 3 exhibit superior performance, with levelized costs of electricity (LCOE) of 49.2 USD/MWh and 55.4 USD/MWh and levelized costs of hydrogen (LCOH) of between 10.7 and 19.5 USD/MWh. The exergoenvironmental impact factor ranges from 66.2% to 73.9%, with an environmental impact rate of 5.4–7.1 Pts/MWh. Despite high irreversibility challenges, the integration of solar energy significantly enhances the system’s exergoeconomic and exergoenvironmental performance, making it a promising alternative as fossil fuel reserves decline. To improve competitiveness, addressing process efficiency and cost reduction in solar concentrators and receivers is crucial.

A parametric study of the exergetic, exergoeconomic, and exergoenvironmental performances of chlorine family thermochemical cycles for sustainable hydrogen production

Hydrogen plays a crucial role in global net-zero policies due to its numerous advantages and is widely regarded as a key future fuel. Clean and sustainable hydrogen production technologies are currently a focal point of research, with thermochemical methods showing promise in achieving environmentally friendly hydrogen. This study builds upon previous research conducted by the authors on thermochemical hydrogen production through chlorine family cycles. It conducts a thorough sensitivity analysis of various system variables that significantly impact the overall performance of these processes. The investigation assesses the performance of chlorine family thermochemical cycles from exergetic, exergoeconomic, and exergoenvironmental perspectives. Exergetic performance parameters include net thermal exergies and exergy efficiencies, exergoeconomic parameters encompass hourly levelized and total cost rates, and exergoenvironmental parameters involve exergoenvironmental factors and component-associated environmental impact rates. The system variables under consideration include ambient temperature, system lifetime, annual operating hours, and operation and maintenance cost factor. The analysis reveals that the system's lifetime notably influences both the exergoenvironmental factors and component-associated environmental impact rates (by about 80%). Meanwhile, its impact on both the hourly levelized (around 11.5%) and total cost rates (approximately 1.2%) is comparatively less significant. Similarly, ambient temperature has a marginal effect on the net thermal exergies and exergy efficiencies of the considered cycles.

New procedure for designing an innovative biomass-solar-wind polygeneration system for sustainable production of power, freshwater, and ammonia using 6E analyses, carbon footprint, water footprint, and multi-objective optimization

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.

Exergy, exergoeconomic, and exergoenvironmental analyses of novel solar- and biomass-driven trigeneration system integrated with organic Rankine cycle

This study proposes a combined cooling, heating, and power (CCHP) system driven by biomass and solar energy integrated with an organic Rankine cycle (ORC). Its exergy, exergoeconomic, and exergoenvironmental performances are investigated. First, the thermodynamic parameters of each material and energy flow for the proposed CCHP system are simulated using Aspen Plus. Second, the exergy and exergoeconomic performances of the system are investigated, and an exergoenvironmental analysis of the system is performed. The results show that the unit exergy costs (UEC) of domestic hot water, electricity generated by an internal combustion engine (ICE) and the ORC, and chilled/heated water under summer/winter conditions are 2.742/2.742, 6.713/6.629, 12.930/12.930, and 27.100/12.530 MW/MW, respectively, with corresponding unit exergoeconomic costs (UEEC) of 41.11/41.11, 124.40/139.20, 181.80/181.80, and 507.10/302.60 USD/MWh, respectively. Meanwhile, the corresponding environmental impact rates per exergy unit are 0.616/0.616, 2.988/3.023, 0.030/0.030, and 6.567/3.072 mPts/MJ, respectively. The results highlight the urgency to prioritize improvements to the solar collector performance to reduce the UEC of electricity generated by the ORC. The absorption chiller/heater, heat exchanger, and ICE exhibit significant potential for enhancing their exergoeconomic performance. Additionally, the gasifier, ICE, and ORC can be optimized to mitigate their environmental impact with relatively minimal exertion.

A comparative exergoenvironmental assessment of thermochemical copper-chlorine cycles for sustainable hydrogen production

Hydrogen is one of the highly promising clean solutions to address the concerns of energy security in the future given the rapid rate of depletion of naturally occurring hydrocarbon sources. However, it is of immense importance that hydrogen is obtained through sources that ensure sustainability. Thermochemical water-splitting processes are among such routes of hydrogen production that are both sustainable and environmentally benign. Thus, this study focuses on assessing the copper-chlorine thermochemical cycles that are among the more promising cycles of the chlorine family in terms of efficiency and cost-effectiveness. Moreover, this study considers a comparative exergoenvironmental evaluation of the four variants of the copper-chlorine cycle that vary in the number and the nature of steps. A comparison in this regard is carried out between the various steps of each cycle in terms of the component-associated environmental impact rates and environmental impact rates of energy transfer as well as the overall environmental impacts of all cycles. In addition, a comparison of the global warming potential of hydrogen synthesized through utilizing various electricity sources is also performed. Based on our evaluations, hydrolysis and electrolysis are the common steps in the five-step cycle, the four-step cycle, and the three-step cycle configuration 1 yielding the highest component-associated environmental impact rates and environmental impact rates of energy transfer, respectively. Conversely, in the three-step cycle configuration 2, the electrolysis and thermal decomposition steps yield the highest corresponding values, respectively. In addition, the three-step cycle configuration 2 (4,869 mPts/h) and the five-step cycle (3,194 mPts/h) have the highest and the lowest component-associated environmental impact rates, respectively while the five-step (530,694 mPts/h) and the four-step (248,050 mPts/h) cycles result in the highest and the lowest environmental impact rates of energy transfer, respectively.

Optimal 4E evaluation of an innovative solar-wind cogeneration system for sustainable power and fresh water production based on integration of microbial desalination cell, humidification- dehumidification, and reverse osmosis desalination

Reliable freshwater production is vital for tackling two of the most critical challenges the world is facing today: climate change and sustainable development. Present work presents an innovative cogeneration system based on solar and wind energies for sustainable production of freshwater, power, and wastewater treatment. For freshwater production and wastewater treatment in this system, the integration of a microbial desalination cell with a humidification-dehumidification and reverse osmosis desalinations has been used. The mentioned systems provide their heat demand from solar energy, and when solar radiation is unable to provide this heat, a hydrogen internal combustion engine drive produces the required heat for the freshwater plant. Excess heat from the hydrogen internal combustion engine is fed into the organic Rankine cycle for more power generation in the whole system to reduce system waste heat and increase efficiency. PEM electrolyzer has been used to supply the hydrogen needed by the internal combustion engine, and this system uses wind turbines to supply the power demand. To evaluate the performance of the whole system, energy, exergy, exergeoeconomic, and exergoenvironmental (4E) analyses have been carried out. Finally, to improve the performance parameters of the system, multi-objective optimization using the Salp swarm algorithm has been used. Investigation of the results show that the proposed system can produce 720 kW of electricity and 5.36 m3/h of freshwater. The energy efficiency of the system is 22.09 %, and its overall cost rate and overall environmental impact rate are 540.33 $/hr and 17.37 Pt/h, respectively. Among the qualitative results obtained in this research, it is possible to mention the high exergy destruction, cost destruction, and environmental impact destruction of the internal combustion engine compared to other equipment used in the proposed system, and this point shows the need to improve this equipment, similar to previous researches. The five-objective optimization results of the proposed system showed that the performance parameters of the system, such as polygeneration energy efficiency, total cost rate, and total environmental impact rate, can be improved by 6.2 %, 1.44 %, and 0.52 %, respectively. The payback period of the proposed system in the optimal state is 6.95 years.

Conventional and advanced exergy-based analyses and comparisons of two novel tri-generation systems based on solid oxide fuel cells and gas turbines

This study conducts conventional and advanced exergy, exergo-economic, and exergo-environmental analyses and comparisons of two tri-generation systems driven by solid oxide fuel cells (SOFCs) and gas turbines (GTs). The proposed systems mainly consist of SOFC, GT, heat recovery steam generator (HRSG), (organic) Rankine cycle, and heat exchanger. The analysis results indicate that the biggest cost rates of exergy destruction and component in both systems appear in SOFCs being 4.4333 $/h and 4.2760 $/h, while the highest environmental impact rates combined with exergy destruction and component in systems 1 and 2 are found in afterburner and HRSG, which are 645.9569 mPts/h and 849.2659 mPts/h. Compared to the conventional analyses, the advanced analyses demonstrate that air compressors own the largest avoidable-endogenous parts of cost rates, while HRSG of system 1 and steam turbine (ST) of system 2 own the highest avoidable-endogenous parts of environmental impact rates being 165.8482 mPts/h and 115.2299 mPts/h.

A hybrid solar-driven vacuum thermionic generator and looped multi-stage thermoacoustically driven cryocooler system: Exergy- and emergy-based analysis and optimization

Significant high-quality heat is wasted in the vacuum thermionic generator (VTIG), which can be efficiently utilized as a prime mover of a bottoming system for cogeneration applications. For this purpose, a new environmental-friendly hybrid system composed of a heliostat solar field, VTIG, and looped multi-stage thermoacoustically driven cryocooler (LMTC) is established, in which the high-temperature heat source of the solar receiver runs the VTIG to generate power, and the LMTC recovers the waste heat of the VTIG to produce a cooling load. Thermodynamic, economic, and environmental analyses of the system are carried out based on exergy and emergy concepts. Moreover, a parametric study is performed to assess the effect of design parameters on the system's thermodynamic, economic, and environmental criteria. Finally, the multi-criteria salp swarm optimization algorithm and decision-making procedures are conducted to improve the exergetic performance and decrease the system's cost and monetary emergy rates along with the environmental impact and ecological emergy rate. Findings depict that at the reliable, optimal operation of the system, the exergetic efficiency can reach 29.36% with a maximum power of 17.2 MW and cooling load of 0.260 MW. The system's cost and monetary emergy rate can be reduced to 0.059 $/s and 5.94 × 1010 seJ/s, with 10.6% and 10% reductions, respectively. Moreover, the environmental impact and ecological emergy rates decline by 6% and 7.4%, respectively. The theoretical findings may offer guidance for the optimum designing and practical running of such a solar solid-state cogeneration system.

Multi-aspect evaluation of a novel double-flash geothermally-powered integrated multigeneration system for generating power, cooling, and liquefied Hydrogen

An integrated renewable geothermal-driven multigeneration system is demonstrated in the present evaluation, consisting of a double-flash geothermal unit, a modified dual-pressure organic Rankine cycle, a Proton exchange membrane electrolyzer, and a Claude Hydrogen liquefication subsystem. The proposed system is examined from various standpoints, and the performance of the system is quantified through the output parameters. Besides, a case study is performed to evaluate the operation of the system in a specified state. Moreover, a sensitivity analysis is conducted to follow the behavior of the system under different conditions. Furthermore, a multi-objective particle swarm optimization algorithm is employed to define the optimum solutions. The results of the study bring out a total generated cooling load of 2.27 MW, a net output power of 10.48 MW, and a liquefied Hydrogen rate of 37.83 kg/h. Also, exergetic efficiency and exergy destruction rate values of 55.89 % and 9.39 MW are obtained, respectively. The exergoeconomic and exergoenvironmental outputs are discussed through a total cost rate of 482.62 $/h, a payback period of 3.27 years, and a product exergy-related environmental impact rate of 9.84 Pts/h.

Conventional and advanced exergy-exergoeconomic-exergoenvironmental analyses of an organic Rankine cycle integrated with solar and biomass energy sources

Considering the huge consumption of traditional energy and the rising demand for electricity, the development of renewable energy is very necessary. In this paper, an energy system integrating biomass energy, solar and two-stage organic Rankine cycle (ORC) is proposed, which uses the stable energy output of biomass energy to compensate for the volatility of solar modules. The proposed system comprises a biomass boiler, photovoltaic thermal panels (PV/T), evaporators, condensers, working medium pumps, turbines, a preheater and an air preheater. In addition, conventional and advanced exergy, exergoeconomic and exergoenvironmental (3E) analyses are carried out. Conventional 3E analyses reveal two components that require priority improvement. They are respectively evaporator 1 with the largest exergy destruction (708.2 kW) and exergy destruction environmental impact rate (775.3 mPt/h) and evaporator 2 with the largest exergy destruction cost rate (19.15$/h). The results of advanced 3E analyses show that the largest avoidable endogenous exergy destruction is condenser 1 (136.6 kW), the largest avoidable endogenous exergy destruction cost rate is condenser 2 (3.377$/h), and the largest avoidable endogenous exergy destruction environmental impact rate is condenser 1 (196.1mPt/h). These mean that these components have great potential for improvement in reducing exergy destruction, saving cost and protecting the environment. In addition, the avoidable endogenous exergy destruction/cost/environmental impact rate of evaporator 2 are negative, so evaporator 2 is not suitable as a priority component for improvement, which is contrary to the conclusions of conventional 3E analyses. It is found that conventional 3E analyses can only point out the biggest exergy destruction point, but cannot indicate whether the components with the greatest exergy destruction have the greatest potential for improvement. However, advanced 3E analyses can show the improvement potential of each component by improving its own performance and the external conditions. Therefore, it is necessary to conduct advanced 3E analyses.

4E, risk, diagnosis, and availability evaluation for optimal design of a novel biomass-solar-wind driven polygeneration system

In this study, an innovative hybrid biomass-solar-wind driven polygeneration system has been presented. The presented system is integrated with two fuel cells and two electrolyzers. Also, considering the approach of using renewable systems, solar, and wind systems have been used in this system. The system integrated by two biomass fuels, olive pits and municipal solid waste (MSW), was examined for energy, exergy, exergoeconomic, and exergoenvironmental (4E) analysis and the results obtained from the 4E analysis of both fuels were compared with each other. The multigeneration system was examined from the point of view of risk and hazard of integrated systems, and the results showed that organic Rankine cycles (ORC) integrated into this system have high risk. Also, the system was evaluated by thermoeconomic diagnosis in terms of malfunction in the operation of the equipment. This evaluation indicates that solid oxide fuel cell (SOFC) performs well compared to other equipment. In addition, the results of this evaluation determined that the system in the functional state can consume fewer local resources than the reference state. Also, the proposed system was tested by assessing reliability and availability. In this analysis, while checking accessibility, the scenarios of increasing accessibility were discussed. Finally, considering this evaluation's effect, the system's cost and environmental impact were calculated. Finally, the polygeneration system was subjected to three-objective and four-objective optimization with the help of genetic and Lichtenberg algorithms. The objective functions selected for optimization are polygeneration efficiency, total cost rate, environmental impact rate, and risk.

Energy, exergy, exergoeconomic and exergoenvironmental analyses of a hybrid renewable energy system with hydrogen fuel cells

In this study, the energy, exergy, exergoeconomic and exergoenvironmental (4E) analyses of a cogeneration system that combines photovoltaic thermal panels (PV/T), evacuated tube solar collectors, an organic Rankine cycle (ORC) and energy storage systems are performed. The cogeneration model is built to meet the load demand of independent houses in remote areas and avoids excessive consumption of traditional energy and environmental pollution. Here, the exergoenvironmental analysis adopts the Eco-indicator-99 method and the all life cycle assessment method is used to calculate the environmental impact of each component. Two comparative studies are conducted to the 4E analyses. The first one compares the comprehensive performance of the battery storage and hydrogen production for energy storage. The results indicate that the cogeneration system using both batteries and hydrogen production for energy storage has the best overall performance. According the exergoeconomic and exergoenvironmental analyses, its environmental impact is 23.6% lower than the cogeneration system using batteries alone and the PV/T can be fully utilized. In addition, the total cost rate is 6.2% lower than the cogeneration system using hydrogen production alone. The second case investigates the effect of adding the evacuated tube solar collectors between the PV/T and ORC on the cogeneration system. The analysis results demonstrate that the evacuated tube solar collectors can increase the heat source temperature of the ORC to increase the power generation of the ORC by 37.14%; however, the total cost rate of the cogeneration system increases by 3.7% and the environmental impact rate increases by 19.8%.

A comparative exergoenvironmental evaluation of chlorine-based thermochemical processes for hydrogen production

Environmental impact assessment of energy generation processes is essential to evaluate their contributions toward the global carbon footprint. Even though hydrogen is a non-carbonaceous energy source, the pathways undertaken for its production can have harmful environmental implications. Thus, this study focuses on investigating the exergoenvironmental performances of the copper-chlorine, iron-chlorine, and magnesium-chlorine thermochemical hydrogen generation processes. This study also performs a comparative exergoenvironmental analysis of the three processes. The performances of the various processes are examined based on of the environmental impact rates of exergy destruction, component-related environmental impact rates, cumulative environmental impact rates, and exergoenvironmental factors. The global warming potentials of the thermochemical cycles are also evaluated and compared for various electricity sources to obtain hydrogen. The modeling and simulation of each process are performed using Aspen-plus by considering various heat recovery approaches for thermal management. The results suggest that the environmental impact rates of exergy destruction are relatively much higher compared to the environmental impact rates associated with the components for all processes. Furthermore, the hydrolysis step yields the highest component-associated environment impact rate for all thermochemical cycles considered (Fe–Cl: 3497 mPts/h, Cu–Cl: 1997 mPt/h, and Mg–Cl: 910 mPts/h). Moreover, the magnesium-chlorine cycle results in the highest environmental impact rate of exergy destruction (650,328 mPts/h) while the iron-chlorine cycle has the highest component-related environmental impact rate (5219 mPts/h) among the three cycles. In addition, the global warming potential of the magnesium-chlorine cycle is relatively higher compared to the copper-chlorine cycle for several electricity sources.

Evaluation and multi-objective salp swarm optimization of a new solid oxide fuel cell hybrid system integrated with an alkali metal thermal electric converter/absorption power cycle

This research introduces a new combination of an alkali metal thermal electric converter (AMTEC) and an absorption power cycle (APC) to boost the performance of the solid oxide fuel cell (SOFC) by recovering the high-quality heat released from the SOFC for further electricity production. The performance criteria of the proposed SOFC/AMTEC/APC hybrid system are mathematically derived using thermodynamic, exergoeconomic, and exergoenvironment-based carbon footprint analysis. Extensive parametric assessment is carried out to evaluate the effect of substantial design parameters on the system's performance criteria. Furthermore, the multi-objective salp swarm algorithm (MSSA) with decision-making techniques is performed to ascertain the hybrid system's maximum power density and minimum cost and environmental impact rates densities. Findings depict the effectiveness and merit of the proposed system with 81% power density improvement compared with the related SOFC-based system. Moreover, the system yields the maximum power density of 9589.37 W/m2, and the corresponding energy and exergy efficiencies are obtained by 55.2% and 57.74%, indicating 59.26% and 53.76% improvements relative to the single SOFC. Furthermore, the minimum cost and CO2 emission rate densities are achieved by 4.26 $/h m2 and 3.32 kgCO2/h m2, respectively, with 31.73% and 42.3% enhancements relative to the base point.

4E and risk assessment of a novel integrated biomass driven polygeneration system based on integrated sCO2-ORC-AD-SOFC-SOEC-PEMFC-PEMEC

This study presents an innovative multi-generation system that produces valuable products such as power, fresh water, hydrogen, and oxygen by burning two different fuels in a biomass burner. Fresh water production in this system is done with the help of an adsorption desolation unit. The evaluations on this system have been done considering two types of biomass fuel from the four perspectives: energy, exergy, exergoeconomic, and exergoenvironmental analysis. In this study, the possible risks of the system have been evaluated using the numerical risk method and process stream index. In addition, by simulating the risks in the system with the help of PHAST software, a more accurate assessment of risk and accident modeling has been done. Furthermore, the integrated system is optimized with seven different optimization algorithms in two modes of four and five objectives. The results show that the polygeneration efficiency for municipal solid waste is 51.84% and for olive pits is 41.05%. The development of the exergoeconomic indicates that the total cost rate of the entire system for municipal solid waste and olive pits equals 0.181 US$/s and 0.156 US$/s, respectively. In evaluating the environmental effects of this system, the total ecological impact rate for municipal solid waste and olive pits equal 128.50 Pts/h and 119.70 Pts/h, respectively. The results obtained from the system risk assessment using the process stream index method show that the stream entering the turbine of one of the proposed organic Rankine cycles (stream 80) is the most dangerous stream among other steams. Also, the results obtained from the numerical risk analysis of the system show that the system will have a lower risk in the case of using municipal solid waste than in the case of using olive pits. Also, this system has been optimized with the help of seven different algorithms in two modes of four and five objectives. The objective functions used in this evaluation are polygeneration efficiency, total cost rate, total environmental impact rate, Levelized cost of electricity, and total risk. The optimization results show that the widespread use of two algorithms, multiobjective particle swarm optimization and Thompson sampling efficient multiobjective optimization, can create a higher percentage of improvement in the objective functions in both four and five objective modes.

An innovative optimal 4E solar-biomass waste polygeneration system for power, methanol, and freshwater production

Modern polygeneration systems have increased the flexibility of production in energy systems. In this paper, a polygeneration system for producing power, freshwater, and methanol using solar and waste resources is defined. By using waste heat recovery in Brayton, Steam Rankine, organic Rankine, and Kalina systems, power has been produced in the proposed system. Methanol is also provided by using CO2 capture from exhaust flue gases and hydrogen produced by Proton Exchange Membrane electrolyzer. The integration of microbial fuel cells, multi-effect distillation, and reverse osmosis desalination has been used for muddy seawater recovery and freshwater production. The proposed system has been analyzed using energy, exergy, exergeoeconomic, and exergoenvironmental (4E) analyses for three biomass fuels. The Multi-Objective Dragonfly Algorithm, Multi-Objective Thermal Exchange Optimization, Multi-objective Salp Swarm Algorithm, and Multi-Objective Water Cycle Algorithm have been used for the optimization of the whole system. In the end, the studied system has been modeled hourly. In this research, machine learning has been used to facilitate modeling the desalination sector, CO2 capture sector, and methanol production sector. Also, it has played a significant role in reducing optimization run time. The modeling results show that Municipal solid waste is the most economical fuel for the study system with a payback of 4.28 years. Date palm waste has also caused fewer environmental impacts than other fuels. The comparison of the results of optimization indicates that Multi-objective Salp Swarm Algorithm is the fastest method for system optimization and can lead to 4.04% and 7.16% improvement in the system cost and environmental impact rate. In general, the energy and exergy efficiencies of the system in the optimal state are calculated as 29.25%, and 23.59%, respectively. The total optimal production of electricity, methanol, and freshwater in the whole system is calculated at 62.86 MW, 1820.78 kg/h, and 63.88 kg/s, respectively. The dynamic analysis of the proposed system also showed that the production of methanol throughout the year will be higher using Municipal solid waste fuel than other fuels.