This study addresses the need for high-efficiency desalination under variable solar conditions, as conventional systems are energy-intensive and electricity-dependent for remote regions. To overcome these constraints, a solar-driven hybrid desalination configuration integrating thermal vapor compression (TVC), humidification-dehumidification (HDH), reverse osmosis (RO), and an energy-recovery turbine (ERT) is proposed. Parabolic trough collectors and thermal storage are used to stabilize operation. A thermo-exergoeconomic model, accelerated by an artificial neural network (ANN) surrogate, is integrated with NSGA-II for multi-objective optimization. To explicitly capture solar variability, Pareto fronts for irradiance levels (Gb = 1, 0.75, 0.5 kW/m2) maximize the energy utilization factor (EUF) and minimize the exergy-based levelized cost of product (LCOP). Results indicate marked improvements at the optimized operating point compared with baseline conditions: freshwater production increases from 42.57 to 68.86 m3/h, GOR rises from 14.74 to 23.84, and EUF improves from 8.563 to 15.88, while LCOP and LCOW decrease to as low as 0.2166 $/kWh and 2.06 $/m3, respectively, across the Pareto solutions. A case study for Siwa Oasis, Egypt, demonstrates the practical applicability of the proposed system for decentralized water supply in solar-rich remote areas. Overall, the ANN-assisted framework provides critical design trade-offs, advancing robust solar-assisted hybrid desalination.

While the European Union (EU) and other Western nations are weaning themselves off the Kremlin's fossil energy resources, global nuclear energy producers remain closely tied to Russia's nuclear industry. One in four nuclear reactors worldwide is connected to Russia (either operating domestically, built abroad, or under construction using Russian technology), and relies on spare parts, maintenance, and fuel from state-owned Rosatom. Russia contributes approximately 6 % of global uranium production, 20 % of conversion capacity, 46 % of enrichment capacity, and 10 % of nuclear fuel fabrication capacity. This work explores the EU's and the global community's dependence on Russian nuclear fuel cycle services. In response to growing geopolitical tensions, particularly after Russia's invasion of Ukraine, the EU has taken steps to reduce this reliance and enhance selfsufficiency. Key measures include expanding uranium conversion capacity, increasing fuel production for VVER440 reactors, and better utilization of existing enrichment infrastructure. Reducing Russia's influence is possible but will require long-term commitment, political determination, and acceptance of higher nuclear energy costs, especially for conversion and enrichment services. With continued effort, full independence from Russian nuclear fuel cycle services is considered achievable between 2030 and 2035.

The global transition towards sustainable energy emphasizes biofuels, particularly biomethanol and biomethane, as critical pathways for decarbonizing the chemical industry and maritime transport. This study proposes an integrated hybrid biofuel production system combining anaerobic digestion, biogas upgrading via amine scrubbing, solid oxide electrolysis cells (SOEC), methanol synthesis, and an oxy-fuel gas turbine. Thermodynamic, exergy, techno-economic, life cycle assessment (LCA), and transient analyses using real-scale industrial data were performed to evaluate system performance comprehensively. Results indicated an overall energy efficiency of 58.09 %, producing 188.68 kg/h of biomethane and 269.54 kg/h of biomethanol. Exergy analysis revealed high efficiency in methanol synthesis (86.95 %) and biogas upgrading (95.23 %), though anaerobic digestion showed significant irreversibilities. Economic assessment demonstrated favorable profitability, with a minimum payback period of 5.72 years and biomethanol production cost as low as 233 /ton under optimal conditions. LCA analysis confirmed significant environmental benefits, showing the system as a net carbon sink (-1.31 x 10-2 kg CO2-eq/kg biomass) under renewable-dominated electricity scenarios. Transient simulations validated the system's robustness against seasonal variations in renewable energy availability. The proposed system, demonstrating low-carbon emissions (0.017 kg CO2 per kg biofuel), presents a viable solution supporting the EU's net-zero goals by providing efficient, sustainable, and economically attractive biofuel production.

Environmental negotiations are complex, and conveying the interaction between science and policy in traditional teaching methods is challenging. To address this issue, innovative educational approaches like serious gaming and role-playing games have emerged. These methods allow students to actively explore the roles of different stakeholders in environmental decision-making and weigh for instance between sometimes conflicting UN Sustainable Development Goals or other dilemmas. In this work the phosphorus negotiation game (P-Game) is for the first time introduced. We present the initial quantitative and qualitative findings derived from engaging 788 students at various academic levels (Bachelor, Master, PhD, and Postdoc) across three continents and spanning 22 different countries. Quantitative results indicate that female participants and MSc students benefitted the most significantly from the P-Game, with their self-reported knowledge about phosphorus science and negotiation science/practice increasing by 71–93

The hydrogen economy is receiving more attention from the global energy industry, highlighting its crucial impact on global energy policies. In this context, the use of hydrogen in the synthesis of biomethanol is essential to the chemical industry and has great promise as a sustainable fuel for global transportation. This study evaluates a system that uses anaerobic digestion, high-temperature electrolysis, and biogas refining to produce biomethane and biomethanol. Novelties of the present study are heat integration and oxygen management between different subsystems, introducing liquified natural gas regasification and gas turbine cycles, and exergy-economic analysis and life cycle assessment using Aspen Plus and Simapro software, respectively. Economic analyses demonstrate lower levelized costs of natural gas and shorter payback periods for systems incorporating liquified natural gas and gas turbine cycles. Moreover, life cycle assessment results indicate a significant reduction of 53% in climate change impacts and 70% in resource use impacts for systems featuring liquified natural gas and gas turbine units. Exergy efficiency improves from 85.07% to 94.4%, largely due to the high exergy efficiency (98.06%) of the liquified natural gas and gas turbine units. By comparing different power sources, the wind turbine scenario demonstrates the potential for significant reductions in climate change and resource consumption compared to those of Poland’s electricity mix.

As a way to lessen the effects of climate change, promoting renewable energy sources to decarbonize the current power sector and industry is gaining popularity. The energy sector still heavily relies on fossil fuels like natural gas, crude oil, lignite, hard coal, and oil, but installed capacity for renewable energy sources (RES) has recently increased substantially. By increasing the percentage of energy derived from renewable sources, the power system will produce more energy intermittently and face significant challenges in keeping the supply and demand balance of the grid in control. When the demand for electricity exceeds supply, electricity storage technologies can transform excess electricity into a storable form of energy (such as the chemical energy of gases or liquids), store it in this form, and then reconvert it to be released back into the power grid. Power to SNG (PtSNG) refers to systems where high-methane synthetic natural gas (SNG) is produced in a reactor using hydrogen and carbon dioxide or/and carbon monoxide. With that kind of system, excess electricity is transformed into synthetic natural gas's chemical energy.The experimental research in this study was conducted using the lab-scale methane generator installation at Silesian University of Technology. The methanation reactor is a fixed-bed type containing a single tube loaded with a catalyst. Tests were performed on two kinds of catalyst: Ni/(Al2O3) and Ru/(Al2O3). In the conducted experiments, the impact of pressure and various volumetric flows of substrates (CO2 and H2 in stoichiometric ratio) on the composition of the generated gas were investigated. The volumetric share of CH4 in the generated synthetic natural gas for a methanation reactor operating at atmospheric pressure ranged from 71.0% to 74.5% for the examined cases of Gas Hourly Space Velocity, and from 88.6% to 89.5% for reaction pressures of 5 bar. Based on the performed experiments, numerical CFD simulation of the methanation reactor was developed in Ansys Fluent software.

Recently, energy policies of different countries put an emphasis on so-called hydrogen economy. Hydrogen is already widely acknowledged as being crucial to decarbonized energy systems and reaching the climate targets for 2050. Replacing fossil fuels with hydrogen allows for the stabilization of the energy system, which is particularly important in the context of the use of RES, and the decarbonization of many industrial sectors. Additionally, crucial is the development of technology for converting hydrogen to other fuels with a broader or distinct range of applications (such as liquid transportation fuels, biomethane, etc.). Systems proposed in this paper fully integrate the needs and trends of the present energy system development by combining the production of hydrogen through high-temperature electrolysis, the use of renewable energy sources, the utilization of carbon dioxide, and energy storage using liquid and gaseous fuels. The paper introduces two main systems for synthetic fuel production, both based on the processes of biomass gasification and high-temperature electrolysis. The first case assumes synthetic natural gas (SNG) production by syngas hydrogenation via methanation process. The second case assumes liquid synthetic fuel production by syngas hydrogenation via Fischer-Tropsch (F-T) synthesis. The thermodynamic and economic potential of SNG and F-T fuels production systems is presented in this work. The considered systems were analyzed for various design conditions such as temperature and pressure, and different H2:CO, and H2:CO2 ratios. The calculated system efficiency of proposed synfuel production systems is 55.66% for SNG production and 24.96% for syncrude production and can be increased up to 66.94% and 30.82% when solid oxide electrolysis and the integration of heat are considered. A sensitivity analysis was conducted to determine the break-even price of SNG and F-T products, considering different scenarios for the costs of feedstock, specifically electricity from RES price. The calculated break-even price of SNG was in the range of 22 – 112 €/MWh and 65 – 225 €/MWh for syncrude.

The improvement of large-scale generation and adoption of sustainable and low-emission fuels is considered crucial to meeting climate mitigation targets set for the global aviation and maritime sectors. The suggested process incorporates renewable energy with biomass gasification and Fischer-Tropsch synthesis to generate biojet fuel and natural gas. LNG regasification aids in utilizing waste heat from the fuel synthesis system, while exhaust gases and residual heat are repurposed to further produce biojet fuel. Process modeling was performed using Aspen Plus software. Key findings indicate that electrical efficiency, specific power consumption, and fuel-based specific hydrogen requirement are 56.2%, 6.0 kWh/L, and 20.0%, respectively.

The global energy landscape highlights the importance of the hydrogen economy, emphasizing its critical role in worldwide energy policies. This study explores a system designed for producing biomethanol and biomethane by integrating anaerobic digestion, biogas upgrading, and high-temperature electrolysis. The system builds on realscale industrial data from an existing anaerobic digestion plant, which has been expanded to include biogas upgrading, an oxy-fuel gas turbine, a Solid Oxide Electrolysis Cell (SOEC), and a methanol production unit. Hydrogen, generated through electrolysis, synthesizes biomethanol by reacting with CO2. Additionally, the system produces biomethane through biogas upgrading. The system incorporates thermal energy integration with an oxy-fuel gas turbine. Life cycle assessment (LCA) results demonstrate the system's environmental potential, achieved negative CO2 emissions of -0.0075 kgCO2eq/kgBiomass in case of photovoltaic panels and -0.0096 kgCO2eq/kgBiomass in case of wind turbines as electricity sources, attributed to efficient conversion of sewage sludge into valuable biofuels. Thermodynamic modeling in Aspen Plus shows an energy efficiency of 58.09 %, with outputs of 188 kg/h of biomethane and 269 kg/h of biomethanol. The techno-economic analysis reveals a payback period of 6.11 years and a levelized cost of biomethanol of 294.37 per ton, indicating the system's economic viability. The LCA further underscores the system's sustainability, supporting its environmental benefits. This comprehensive analysis provides valuable insights into the viability and environmental impact of the proposed biofuel production system.

Due to the growth in the share of renewable energy sources (RES) in the power generation sector worldwide and their intermittency, storage of surplus electricity is needed. The technology known as Power to X (PtX) facilitates the extended storage of excess electricity by converting it into gaseous or liquid fuels such as hydrogen, methane, ammonia, or methanol. This study examines the potential of synthetic natural gas (SNG) technology as a viable energy storage solution. The paper introduces three distinct SNG production systems, all of which are based on the processes of biomass gasification and methanation. Case 1 assumes further CO2 capture from generated SNG, and Cases 2 and 3 additionally assume hydrogen production and almost complete CO2 utilization by syngas hydrogenation via the methanation process. The methanation process converts syngas and hydrogen into SNG with a high methane content (>90 vol% dry), that can be injected into the natural gas grid. The thermodynamic and economic potential of SNG production systems is presented in this work. The simulations were conducted using the AspenONE software. The methanation process was analyzed for various design conditions such as methanation temperature and pressure, and different H-2:CO, and H-2:CO2 ratios. The estimated cold gas efficiency of proposed SNG production systems varies from 63.27% to 77.10% and can be increased up to about 69.10-75.58% when the recovery of heat from methanation is considered. A sensitivity analysis was conducted to determine the break-even price of SNG, considering different scenarios for the costs of feedstock, specifically biomass and electricity. The results indicate that under the most optimistic conditions, the break-even price of SNG is estimated to be 115 /MWh(SNG), 58 /MWh(SNG) and 67 /MWh(SNG) for Cases 1, 2, and 3, respectively.

The hydrogen economy is of crucial importance in energy policies worldwide. Moreover, there are many benefits to producing biomethanol because it can be used in engines to achieve high efficiency, zero emission and lower risks of flammability. This research aims to evaluate a biomethanol and natural gas generation system that uses biomass gasification and high-temperature electrolysis. Thermal integration is applied between the steam generators of the gasifier and electrolyzer. The LNG regasification unit and an open Brayton cycle are responsible for power and natural gas production. The flue gas leaving the gas turbine leads to additional production of biomethanol. Oxygen management is applied between three different subsystems and there is a large amount of CO2 utilization as well. The results of energy analysis and thermodynamic modelling of an integrated system conducted in Aspen Plus indicate that the proposed cycle produces 16 644 ton/yr of natural gas, 1412 ton/yr of biomethanol, uses 3450 ton/yr of CO2, and has an efficiency of 81.96 %. Raising the methanol reactor temperature from 220 degrees C to 350 degrees C significantly enhances biomethanol capacity from 1015 ton/yr to 1930 ton/yr, leading to a 4 % increase in total energy efficiency.

The present study is dedicated to the thermodynamic evaluation of an innovative system for the generation of biomethanol and natural gas, utilizing the processes of biomass gasification and high-temperature electrolysis. The recovery of waste heat from a compressed air energy storage (CAES) system serves as a crucial thermal energy source. Recognizing the periodic nature of CAES operations, a thermal energy storage (TES) system has been used to ensure a consistent supply of heat to the biomethanol production facility. The liquefied natural gas (LNG) regasification unit and an open Brayton cycle play a dual role, contributing not only to power generation and natural gas production but also to enhancing biomethanol production through the utilization of flue gases. The results of a thermodynamic modeling conducted within the Aspen Plus program demonstrate the production of 69251 ton/year of natural gas, 1424 ton/year of biomethanol, with a CO2 consumption of 3452 ton/year, resulting in an impressive overall energy efficiency of 95.27%. The electrolyzer exhibits the highest power consumption at 1035 kW. Sensitivity analysis showed that net input electricity increases with an enhanced number of solid oxide electrolysis cell (SOEC) cells, while biomethanol capacity rises due to enhanced electrolysis size and hydrogen production rate.

Energy policies around the world are increasingly highlighting the importance of hydrogen in the evolving energy landscape. In this regard, the use of hydrogen to produce biomethanol not only plays an essential role in the chemical industry but also holds great promise as an alternative fuel for global shipping. This study evaluates a system for generating biomethanol and biomethane based on anaerobic digestion, biogas upgrading, methanol synthesis unit, and high-temperature electrolysis. Thermal integration is implemented to enhance efficiency by linking the oxy-fuel gas turbine unit. The integrated system performance is evaluated through thermodynamic modeling, and Aspen Plus V12.1 is employed for the analysis. Our findings show that the primary power consumers are the Solid Oxide Electrolysis Cell (SOEC) and Methanol Synthesis Unit (MSU), with the SOEC system consuming 824 kW of power and the MSU consuming 129.5 kW of power, corresponding to a production scale of 23.2 kg/h of hydrogen and 269.54 kg/h of biomethanol, respectively. The overall energy efficiency is calculated at 58.09%, considering a production output of 188 kg/h of biomethane and 269 kg/h of biomethanol. The amount of carbon dioxide emitted per biofuel production is equal to 0.017, and the proposed system can be considered a low-carbon emission system. Key findings include significant enhancements in biomethanol capacity and energy efficiency with higher temperatures in the methanol reactor.

The increasing demand for power and cooling generation presents a dual challenge: an unavoidable increase in carbon emissions from fossil fuel combustion and the associated difficulties in meeting the escalating investment requirements for power plant generation. As a result, there is an urgent call for the advancement of innovative cycles that not only improve performance, but also play a role in mitigating carbon emissions. This study presents a novel approach to biogas-powered cogeneration with the objective of concurrently producing electricity and cooling while utilizing heat from liquefied natural gas. The primary objective is to achieve a reduction in carbon emissions compared to similar existing work. The innovative system combines an open-loop Brayton cycle (gas turbine cycle) powered by biogas, a closed-loop Brayton cycle, a liquefied natural gas open power generation cycle, and a dual-stage combined cooling and power unit consisting of an organic Rankine cycle integrated with an ejector refrigeration cycle. A thermodynamic and economic analysis was conducted to assess the performance of the current study in comparison to previous models. To achieve optimum conditions, a comprehensive multi-objective optimization has been used, taking into account crucial decision variables, energy and exergy indicators, the carbon emission per energy ratio of the product, and the overall cost of the unit product. The results obtained underscore the environmental superiority of this system over other proposals. In the most optimal state, this system demonstrates a remarkable 48

Several strategies have emerged for utilizing waste heat across diverse sectors. Yet, integrated systems that merge power generation with freshwater production, especially those leveraging renewable energy, remain relatively unexplored. Addressing this gap, a novel solar biomass-driven system is under development for power generation and desalination facilities. In the suggested system, rather than wasting the energy of a supercritical CO2 power cycle, a bottoming cycle is proposed to augment energy utilization factor (EUF). By integrating humidificationdehumidification, thermal vapor compression, and reverse osmosis (HDH-TVC-RO) with a multi-effect distillation (MED) unit, freshwater production rate is significantly enhanced. The outcomes reveal a freshwater output of 29.36 kg/s, a gained output ratio (GOR) of 17.36, and the EUF of 3.372. Various nanofluids have been assessed for the solar collector and due to superior total exergy efficiency and less corrosion effects, Cu- and carbon-based nanoparticles are recommended. Sensitivity analysis indicates that increasing the pressure ratio of compressors boosts the total GOR. Furthermore, adjustments to both the parameters of pressure of steam fed to HDH-TVC, and the compressor pressure ratio demonstrate a linear effect on EUF behaviour.

Biogas-fueled decentralized energy systems featuring gas turbines emerge as pivotal players in the quest for more adaptable and eco-friendly energy solutions. This study presents the design of a cutting-edge multigeneration system that harnesses the potential of a gas turbine coupled with ejector-driven dual-loop bi-evaporator technology, reverse osmosis desalination, proton exchange membrane electrolysis, and an organic Rankine cycle. The research encompasses an extensive sensitivity analysis and deploys a genetic algorithm-based optimization technique. Through meticulous Optimization, the system achieves remarkable outcomes, including electricity generation, cooling capacity, heating capacity, desalinated water production, and hydrogen yield, measured at 957.3 kW, 231.4 kW, 272.3 kW, 7.336 kg/s, and 0.99 kg/h, respectively. Notably, this performance surpasses the base case by 2% and 8.9%, yielding exergy efficiency and total unit cost improvements of 33.3% and 16.4 $/GJ. Among the critical decisions made was selecting an organic working fluid for the organic Rankine cycle. Through rigorous evaluation, isobutene emerged as the optimal choice, demonstrating significantly improved output power compared to alternatives. Isobutane as the working fluid led to a substantial increase in overall exergy efficiency and a resultant total unit cost of 18.06 $/GJ, accompanied by an impressive 23.48% exergy efficiency.

With a projected increase of over 30 % by 2050, refrigeration systems are already responsible for 17 % of all electrical energy. To address these critical environmental concerns and enhance overall efficiency while reducing costs, a shift to eco-friendly and neutral impact alternatives is imperative. When carbon dioxide (CO2) is used as a working fluid since it is a natural gas, coupled with optimized system configurations, it holds the promise to mitigate these challenges effectively. In this study, a novel transcritical refrigeration cycle with an ejector operating with CO2, is proposed to further improve system efficiency. To validate the system's performance, a comprehensive thermodynamic model was established, and published results were used for validation. Remarkably, the new system demonstrated higher energy and exergy efficiency when compared to existing systems documented in the literature. To identify the most influential factors affecting cycle performance, an ANOVA analysis was conducted. The evaporator temperature was shown to be the most important variable, impacting the COP, exergy efficiency, and overall cost of the product by a combined 81, 46, and 75 %, respectively. In addition, the Non-dominated Sorting Genetic Algorithm-II (NSGA-II) method was used to maximize the effectiveness of the system. This method of multi-objective optimization took into account both the thermodynamic criterion of exergy efficiency and the economic criterion of total product cost. The integration of these criteria in the optimization process allows for an environmentally friendly and economically viable NEETR cycle.

This paper presents the results of tests conducted on the methanation reactor installation at the Silesian Uni-versity of Technology. The reactor is a fixed-bed type and it consists of one tube filled up with the nickel powder and Ru/(Al2O3) used as a catalyst. The results obtained before and after the modernization of the installation are described. The produced gases are analyzed in the VARIO Luxx of MRU air Emission Monitoring Systems gas analyzer. During the tests, the temperature in three zones of the reactor was measured continuously. The gauge pressure at the inlet and outlet of the reactor was also measured. In the performed tests, the effect of different volumetric flows of substrates (CO2 and H2 in stoichiometric ratio) and the effect of pressure on the produced gas composition were examined. Additionally, for the measurement series carried out on the laboratory stand, the estimated CO2 to CH4 conversion factors were calculated. For the operation of a methanation reactor under atmospheric conditions, the volumetric share of CH4 in the produced Synthetic Natural Gas was between 71.0% and 74.5% for analyzed cases of Gas Hourly Space Velocity and for a reaction pressure of 5 bar, CH4 content was between 88.6 and 89.5%.