Search

The performance of CO 2 -assisted oxidative dehydrogenation of propane to propylene is investigated. The energy performance matrices are defined as energy efficiency and exergy efficiency at both the reactor level and the overall system level. Oxidants are the main factor that dictates the performance of the dehydrogenation of propane. Oxygen is a strong oxidant which helps in promoting the endothermic dehydrogenation of propane. CO 2 is considered a mild oxidant that hinders the over-oxidation of propane. The addition of CO 2 promotes propane conversion but sacrifices the other performance matrices including propylene selectivity and the H 2 /CO ratio of the syngas. Consequently, the energy and exergy efficiencies of the reactor as well as the DHP system decrease with increasing CO 2 supply. The addition of O 2 has positive impacts on the energy performance matrices at a certain temperature range (from 863 K to 1273 K). However, the addition of O 2 leads to an adverse impact on the propylene selectivity and H 2 /CO ratio of the syngas. Under the absence of O 2 , the DHP exhibits a propane conversion of 91% with the propylene selectivity and system exergy efficiency of 90% and 86%, respectively when the CO 2 /C 3 H 8 ratio of 0.25 at 973.15 K. This work provides strong evidence that the reaction performance matrices have a strong relation to the energy performance matrices and offers a baseline for future research and optimization in the presence of O 2 and CO 2. [Display omitted] • The performances of dehydrogenation of propane (DHP) are investigated. • The main product are propylene and syngas. • CO 2 and O 2 enhances propane conversion but suppresses propylene selectivity. • CO 2 and O 2 has an adverse effect on energy and exergy efficiencies. • DHP shows propane conversion and selectivity of 91% and 90%, respectively. [ABSTRACT FROM AUTHOR]

The energy demand in Turkey is increasing continuously because of the fact that it is a developing economy. However, it has limited energy sources. As a result of these circumstances, energy efficiency projects are essential for industry and other energy consumption areas. This paper proposes energy recovery by analyzing energy and exergy in a porcelain tableware firing kiln, a ceramics industry branch. The actual data obtained from the measurements made on the kiln were used in the energy and exergy analysis calculations. The energy consumption of the glaze kiln has been calculated as 3868 kJ/s. The incoming energy is lost around 14.78% by the main exhaust flue gas and 28.58% by the cooling exhaust gas. The primary energy casualties are kiln walls and other losses. They are 43.36% and 38.9%, respectively. Finally, according to energy and exergy analyses, suggestions were made on the processes with high energy losses, and depreciation was made. [ABSTRACT FROM AUTHOR]

In this study, an innovative woody biomass‐fueled hybrid tetrageneration system composed of a single‐effect lithium bromide‐water absorption refrigeration system, a reverse osmosis desalination system, two organic Rankine cycle for the production of cooling, heating, power, and freshwater in two distinct configurations (configurations A and B), compared and discussed using energy, exergy, economic, and exergoeconomic analyses. The poplar sawdust used as a local woody biomass fuel was a by‐product of the Iran Wood and Paper Industries Company, located in northern Iran. The results revealed that the highest heating production and lowest exergy destruction were related to configuration B. The overall cost of configuration A was higher than that of configuration B. A detailed sensitivity analysis was also developed to study the effect of various factors on the thermodynamic and economic performance of the proposed configurations. By increasing the turbine inlet temperature of ORC1 from 625 to 692 K, the total sum unit costs of product of the system in configurations A and B decreased by 20 and 23 $ GJ−1, respectively (about 21%). [ABSTRACT FROM AUTHOR]

In response to escalating environmental concerns and the imperative to institute effective energy management strategies, the pursuit of alternative fuels has emerged as a pivotal endeavor for realizing sustainable energy solutions. Methanol and ammonia have surfaced as particularly promising and environmentally friendly liquid fuels, holding significant potential for aiding in the attainment of decarbonization objectives and addressing global energy requirements. This research proposes and scrutinizes a sophisticated cogeneration system integrating solid oxide fuel cells (SOFCs), gas turbine (GT), steam Rankine cycle, and organic Rankine cycle. Direct utilization of ammonia and methanol as fuel in this intricate system is examined, with the design and modeling facilitated through the utilization of Aspen HYSYS V.12.1. The thermodynamic performance of the proposed system is rigorously assessed by employing the foundational principles of the first and second laws of thermodynamics. The direct SOFCs fueled by ammonia and methanol exhibit notable energy efficiencies of 64.25 % and 58.42 %, respectively. Remarkably, the amalgamated systems showcase heightened energy efficiencies, witnessing a commendable increase of 12.64 % and 10.66 % when powered by ammonia and methanol, respectively, as compared to individual SOFC systems. Examination of exergy destruction reveals the SOFC as the principal contributor, with electrochemical and chemical processes constituting the primary sources of irreversibility. Additionally, explicit values for exergy destruction in the GT, afterburner, and heat exchanger components are provided. A comprehensive parametric study underscores the pivotal role of the fuel utilization factor (Uf), identifying a value of 0.85 as optimal and significantly augmenting the thermodynamic efficiency of the system. This analysis not only substantiates the potential of ammonia and methanol as effective carriers for hydrogen but also underscores the efficacy of waste heat recovery as a viable strategy for enhancing the overall thermodynamic performance of an SOFC system. The findings presented herein contribute valuable insights, paving the way for the strategic utilization of alternative fuels and cogeneration systems in the broader context of sustainable and environmentally conscious energy solutions. [ABSTRACT FROM AUTHOR]

The objectives of this paper are to analyse sustainability of wind energy potential, and select the best wind turbine model for installation at the study site. The study used the two-parameter Weibull distribution as the basic mathematical model to analyse half-hourly data collected at the Tanzania Meteorological Department data collection centre for two consecutive years, 2021 and 2022. Statistical methods were used to validate the best fit between the standard deviation, energy pattern, moment, and wind variability methods. The moment method was selected based on the validation results. The results of this research show that more than 66.7% of the most probable monthly wind speed in 2021 is between 5 and 8.6 m/s, while more than 75% is between 5 and 13.7 m/s in 2022. Furthermore, based on the National Renewable Energy Laboratory wind power classification, the study concluded that the site has a sustainable wind energy potential, as more than 90% of the 24 months and 8 climatic seasons have a calculated wind energy density between 700 and 7000 MWh/m². In addition, based on the calculated capacity factor and average power, all turbines selected in this study have highcapacity factors greater than 25% and can be considered for selection based on the projected investment budget. However, the most cost-effective wind turbine model was found to be the POLARIS P62-1000, due to its highest capacity factors and average power output on an annual, seasonal, and monthly basis. [ABSTRACT FROM AUTHOR]

Heat pumps are recognized as a key tool in the energy transition toward a carbon-neutral society, enabling the electrification of the heating sector at least for low- and medium-temperature heat demands. In recent years, natural refrigerants have been reconsidered due to their low environmental impact: among them, CO2 is a safe option without an impact on the ozone layer and low global warming potential compared to synthetic fluids. However, as a consequence of its thermophysical properties, its thermodynamic cycle is transcritical and is particularly suitable for specific end-user temperature profiles. This paper analyzes in a systematic and thorough way the most significant modifications to the reference cycle that have been proposed in the literature to improve the performance, finding how the optimal configurations change with a change in the rated operating conditions (inlet temperature and temperature glide of the heat demand, and ambient temperature). Exergy analysis explains why there is an optimal gas cooler pressure and why its trend with the average temperature is split into two distinct regions, clearly recognizable in all cycle layouts. The maximum coefficient of performance (COP) of the reference cycle varies in the 1.52–3.74 range, with a second-law efficiency of 6.4–36.1%, for an optimal gas cooler pressure of up to 15.45 MPa, depending on the ambient temperature and end-user temperature profile. The most effective modification is the cycle with an ejector and internal heat exchanger, which raises the COP to 1.84–4.40 (second-law efficiency 8.7–45.56%). The presented results provide an extensive guide to understanding the behavior of a transcritical CO2 cycle and predict its performance in heat pump applications. [ABSTRACT FROM AUTHOR]

This study reports the comparative energy and exergy analysis of ortho-para hydrogen and non-ortho-para hydrogen conversion in hydrogen liquefaction process. Two cases were simulated, case A – hydrogen liquefaction with ortho-parahydrogen conversion and case B – hydrogen liquefaction without ortho-parahydrogen conversion. This is the first study that presents a comparative energy and exergy analysis between such two cases. In this research, a hydrogen liquefaction process was designed adopting cascaded five-stage Brayton refrigeration cycle. The process was simulated in Aspen PLUS. The process used a mixed refrigerant (of liquefied natural gas) refrigeration cycle to precool the gaseous hydrogen feed from 26 °C temperature to −192 °C temperature, and mixed refrigerant (of nelium) was subsequently used to further deep-cool the the hydrogen stream from −192 °C temperature to −245.99 °C temperature in the cryogenic section of the process. Liquefaction was achieved by expanding the hydrogen through Joule-Thomson valve at −248.37 °C and 1 bar. The simulated results of the two cases showed the specific energy consumption of case A to be 8.45 kWhr/kg LH , and that of case B to be 15.65 kWhr/kg LH respectively. The results also indicated a total exergy efficiency of 92.42% in case A and 87.18% in case B. The research results showed that the hydrogen liquefaction designed with configuration of ortho-parahydrogen conversion has better performance indicators than the liquefaction without ortho-parahydrogen conversion. Therefore, hydrogen liquefaction with ortho-parahydrogen conversion can be considered in the design and development of new hydrogen liquefaction plants. Process optimization is recommended to further enhance the specific energy consumption and exergy efficiency of both processes. • Comparative analysis of ortho-para and non-ortho-para hydrogen conversion. • Ortho-para Process is more energy efficient than non-ortho-para process. • Average exergy efficiency of 89.8% achieved in the analysed processes. • Integration of three refrigeration cycles to achieve hydrogen liquefaction. [ABSTRACT FROM AUTHOR]

Featured Application: The work in this paper provides some basic theoretical and practical reference value for the energy and exergy analysis, calculation, process optimization, and energy conservation research of the hydrogen-based direct reduction shaft furnace process, which is helpful for promoting its further industrial application. The traditional production mode using coal as the main energy source is not conducive to the sustainable development of the iron and steel industry (ISI). The hydrogen-based direct reduction shaft furnace (HDRSF) process is a feasible technical route for promoting the green development of the ISI. However, there is a lack of comprehensive analysis with respect to the energy utilization and process flow of the HDRSF method. To address these issues, a systemic material–energy–exergy model of HDRSF is established. An improved HDRSF process incorporating waste heat recovery is also proposed, and energy consumption intensity and exergy intensity are used as assessment metrics. This study's findings indicate that the proposed waste heat recovery can considerably lower gas demand and energy consumption intensity, but exergy intensity has little effect. The reducing gas demand drops from 2083 m3 to 1557 m3, the energy consumption intensity drops from 2.75 × 107 kJ to 1.70 × 107 kJ, and the exergy intensity drops from 1.08 × 107 kJ to 1.05 × 107 kJ when the reducing gas temperature is 900 °C, H2:CO = 1:1; meanwhile, the recovery rate of waste heat reaches 40%. This study can serve as a reference for actual HDRSF process production. [ABSTRACT FROM AUTHOR]

This study aims to assess and examine the gas turbine power generating system at the Qayyarah gas station in Nineveh City, Iraq. The evaluation conducted under real weather conditions for the year 2023. The gas turbine unit has a maximum load output capacity estimated at 125 megawatts. The system comprises a gas turbine, an air compressor, and a generator, all coupled by a shared shaft. Its functions based on a straightforward Joule-Brayton cycle. An analysis of the energy and exergy of the previously mentioned unit, taking into account the principles of conservation of mass, the first law, and the second law. The study specifically focused on examining the impact of several elements, including ambient temperature, compression ratio, relative humidity, and operational load. Two techniques used to replicate company data: the first approach included scripting the simulation using Excel, while the alternative option utilized Aspen HYSYS. The performance of the gas unit evaluated using the average data from each month of the simulation for that year. The simulation findings indicated that the combustion chamber is the primary component responsible for energy dissipation, and the highest energy yield may be achieved from fuel in the form of chemicals. The results of both approaches demonstrated that the maximum energy and energy efficiency achieved around 40.23% and 31.76%, respectively. [ABSTRACT FROM AUTHOR]

This paper designs a controller based on the energy coupling combined with the adaptive principle to address the issues of swing and inaccurate positioning caused by load changes in a four-rotor hanging load system. Considering load variability during modeling, it is divided into two parts: a fixed part and a changing part. The changing part involves online estimation using the adaptive principle. This approach effectively resolves the variable load problem while addressing the initial value problem associated with the load mass estimation. The controller accounts for the coupling between the load's swing angle and the displacement in the four-rotor system. It exploits the underactuated characteristics of the system to suppress the load swing angle. Additionally, a potential function is incorporated into the controller to compensate for the positioning error resulting from estimation errors. The simulation results show that the designed controller can adapt to various flight transportation situations. The experimental results show that the designed controller can accurately locate and effectively suppress the swing caused by variable load compared with the conventional controller. [ABSTRACT FROM AUTHOR]

Purpose – This paper endeavors to create a predictive model for the energy consumption associated with the multi-material fused deposition modeling (FDM) printing process. Design/methodology/approach – An online measurement system for monitoring power and temperature has been integrated into the dual-extruder FDM printer. This system enables a comprehensive study of energy consumption during the dual-material FDM printing process, achieved by breaking down the entire dual-material printing procedure into distinct operational modes. Concurrently, the analysis of the G-code related to the dual-material FDM printing process is carried out. Findings – This work involves an investigation of the execution instructions that delineate the tooling plan for FDM. We measure and simulate the nozzle temperature distributions with varying filament materials. In our work, we capture intricate details of energy consumption accurately, enabling us to predict fluctuations in power demand across different operational phases of multi-material FDM 3D printing processes. Originality/value – This work establishes a model for quantifying the energy consumption of the dual-material FDM printing process. This model carries significant implications for enhancing the design of 3D printers and advancing their sustainability in mobile manufacturing endeavors.

In response to the escalating emphasis on sustainability across diverse sectors, this study addresses the imperative to combat environmental degradation through conscientious development. The primary focus is on assessing the feasibility of replacing fossil fuels with renewable alternatives in internal combustion engines (ICEs) equipped with direct fuel injection. The research employs energy and exergy analyses, coupled with economic analysis, to comprehensively evaluate the performance of fuels and blends. Applying the Lotus Engine software, computational analyses are conducted, taking into account the specific geometry of the engine. Simulations explore different λ‐factors to identify optimal performance configurations for each fuel or blend. Noteworthy outcomes reveal that blends featuring green hydrogen yield remarkable improvements, showing high torque (max. +11.5%), power (max. +14.35%), thermal efficiency (max. +3%), and exergy efficiency (max. +21.56%). These blends also demonstrate reduced operating costs (max. −10%), although with higher exergy losses, indicating areas for potential enhancement. Conversely, fuels containing ethanol show intermediate values between the blends and pure fuels. Consequently, this study effectively establishes the significance of these fuels in ICEs, supported by comprehensive energy, exergy, and economic analyses. The findings underscore the promising potential of renewable fuels as viable alternatives to fossil fuels, marking a substantial stride towards sustainable energy solutions and environmental preservation. [ABSTRACT FROM AUTHOR]

Biomass combustion produces air pollutants, causing high mortality rates, while electric cooking, which is efficient and eco-friendly, reduces mortality and maximizes socio-economic and ecological benefits. Thus, the primary purpose of this study is to compare the performance of domestic and imported household electric hotplate stoves via experimental investigation. For the study, 20 households have been purposively selected in Bahir Dar, Ethiopia from low- and middle-income groups. Following that, the researchers trained the participants and enumerators to record the energy consumption and time taken for each cooking event. The experiments have been conducted using medium-sized domestic and imported electric hotplate stoves for 15 days each. Digital energy meters have been used to record the daily cooking energy demand. Participants record the daily data using the developed Excel spreadsheet. Accordingly, the study disclosed that the average daily cooking energy consumption per household for locally-made and imported electric cookstoves is 3.55 kWh and 2.81 kWh, respectively. The result also reveals that local electric stoves are subjected to inferior efficiency and higher heat losses. On the other hand, the analysis of the average time required to cook a meal revealed that cooking with imported cookstoves took slightly longer than cooking with locally-made cookstoves. This is because as there is no power-control mechanism, locally-made electric stoves usually work at maximum power rate and cook faster than imported ones. Moreover, the average monthly energy expense per household using these stoves in their respective ways were $3.90 (213.33ETB), and $3.1(169.86ETB), suggesting that locally manufactured stoves have higher energy cost bills. An independent T-test results revealed a significant difference (p

This article analyzes the processes of compressing hydrogen in the gaseous state, an aspect considered important due to its contribution to the greater diffusion of hydrogen in both the civil and industrial sectors. This article begins by providing a concise overview and comparison of diverse hydrogen-storage methodologies, laying the groundwork with an in-depth analysis of hydrogen’s thermophysical properties. It scrutinizes plausible configurations for hydrogen compression, aiming to strike a delicate balance between energy consumption, derived from the fuel itself, and the requisite number of compression stages. Notably, to render hydrogen storage competitive in terms of volume, pressures of at least 350 bar are deemed essential, albeit at an energy cost amounting to approximately 10% of the fuel’s calorific value. Multi-stage compression emerges as a crucial strategy, not solely for energy efficiency, but also to curtail temperature rises, with an upper limit set at 200 °C. This nuanced approach is underlined by the exploration of compression levels commonly cited in the literature, particularly 350 bar and 700 bar. The study advocates for a three-stage compression system as a pragmatic compromise, capable of achieving high-pressure solutions while keeping compression work below 10 MJ/kg, a threshold indicative of sustainable energy utilization.

This study systematically examines the energy dissipation mechanisms and ballistic characteristics of foam sandwich panels (FSP) under high-velocity impact using the explicit non-linear finite element method. Based on the geometric topology of the FSP system, three FSP configurations with the same areal density are derived, namely multi-layer, gradient core and asymmetric face sheet, and three key structural parameters are identified: core thickness (tc), face sheet thickness (tf) and overlap face/core number (no). The ballistic performance of the FSP system is comprehensively evaluated in terms of the ballistic limit velocity (BLV), deformation modes, energy dissipation mechanism, and specific penetration energy (SPE). The results show that the FSP system exhibits a significant configuration dependence, whose ballistic performance ranking is: asymmetric face sheet > gradient core > multi-layer. The mass distribution of the top and bottom face sheets plays a critical role in the ballistic resistance of the FSP system. Both BLV and SPE increase with tf, while the raising tc or no leads to an increase in BLV but a decrease in SPE. Further, a face-core synchronous enhancement mechanism is discovered by the energy dissipation analysis, based on which the ballistic optimization procedure is also conducted and a design chart is established. This study shed light on the anti-penetration mechanism of the FSP system and might provide a theoretical basis for its engineering application.

Despite energy-related financial concerns and the growing demand for sustainability, many energy efficiency measures are not being implemented in industrial practice. There are a number of reasons for this, including a lack of knowledge about energy efficiency potentials and the assessment of energy savings as well as the high workloads of employees. This article describes the systematic development of an expert system, which offers a chance to overcome these obstacles and contribute significantly to increasing the energy efficiency of production machines. The system employs data-driven regression models to identify inefficient parameter settings, calculate achievable energy savings, and prioritize actions based on a fuzzy rule base. Proposed measures are first applied to an analytical real-time simulation model of a production machine to verify that the constraints required for the specified product quality are met. This provides the machine operator with the expert means to apply proposed energy efficiency measures to the physical entity. We demonstrate the development and application of the system for a throughput parts-cleaning machine in the metalworking industry. [ABSTRACT FROM AUTHOR]

Solar desalination is a broad research field in the production of freshwater. The efficiency of the natural conversion solar desalination system is the only limitation to becoming its commercialization. It needs 1 m2 area for getting approximately 4.5 L of fresh water/day. In active methods 1 m2 area of solar still produce yield up to 10 L/day. In this study a new technology of fixing the photovoltaic cell (PV cells) in the natural passive solar still condenser glass to harvest both freshwater as well as electrical power generation is proposed. The experiments were carried out with conventional solar still of a glass surface area of 0.5 m2, still with an effective glass surface area of 0.3812 m2 and 36 PV cells taken up area of 0.1188 m2, and still with effective glass surface area of 0.3020 m2 and 60 PV cells taken up area of 0.198 m2. The study found that conventional solar still produced 2140 mL/day of yield, still with 36 PV cells produced 1380 mL/day of yield and 98 W of electrical power and still with 60 PV cells produced 840 mL/day of yield and 165 W of electrical power. This hybrid system, solar still with PV cells, produce both fresh water and electrical power. The fresh water yield and electrical power generation depends on the effective area of the solar still glass surface area and area occupied by PV cells attached to the solar still glass cover. [ABSTRACT FROM AUTHOR]

Microwave-assisted pyrolysis is an effective method for recycling plastic wastes into oils that can be used for aviation fuels. In this study, energy and economic analyses of aviation oil production from microwave-assisted pyrolysis of polystyrene were performed. The total energy efficiency, recovered energy efficiency, unitary cost, unitary energy economic cost, relative cost difference, and energy economic factor were detailed. And the effects of microwave power, pyrolysis temperature, microwave absorbent loading, and microwave absorbent type on these parameters were covered. It was found that pyrolysis temperature has the most significant effect on the unitary cost and unitary energy economic cost of aviation oil, and- microwave absorbent type has a significant influence on energy economic factor during the whole microwave-assisted pyrolysis process. The optimum reaction conditions at the tonnage system for pyrolysis of 1 t polystyrene were microwave power of 650 W, pyrolysis temperature of 460 °C, and silicon carbide (microwave absorbent) at a loading of 2 t (twice than feedstock loading). At these optimal conditions, the total energy efficiency, recovered energy efficiency, unitary cost, unitary energy economic cost, relative cost difference, and energy economic factor were 62.78%, 96.51%, 3.21 × 104 yuan·t−1, 779 yuan·GJ−1, 1.49, and 71.02%, respectively. [ABSTRACT FROM AUTHOR]

The paper presents the performance evaluation of a modified indirect solar dual collector dryer (MIS2CD) integrated with a thermal storage system for drying myrobalan slices. The design of the solar collector and solar collector with thermal storage was to supply uninterrupted thermal energy to the drying chamber during sunny and sunset hours. To evaluate the dryer performances, one lot (20 kg) of myrobalan was dried in the MIS2CD, and as a result, the thermal efficiency and energy supply period of MIS2CD increased by 12 ± 02% and 41 ± 1.2%, respectively. Drying characteristics of myrobalan slices in MIS2CD, TD, and OSD were studied and compared. A two-term exponential model best explains the drying kinetics of myrobalan slices dried in MIS2CD. The dried sample in MIS2CD results in lesser ΔE* values than TD and OSD methods. The highest exergy efficiency of 78.2% and lower exergy losses were recorded. The energy payback period of the MIS2CD was evaluated as 1.42 years. The CO2 emitted and CO2 reduced reduction are calculated for drying myrobalan in MIS2CD for a lifetime (20 years) of 67.85 kg and 20.65 tons, respectively. The capital cost of the solar dryer design was estimated depending on the economic considerations of the state. The drying hours were increased in MIS2CD against OSD by 59% on the annual sunny days (210 days). The sample drying period MSD and TD to reach the final moisture level of 7% was 9 h and 5 h, respectively. The total economic benefit is 22,622 INR (annually), and the 2.08 benefit–cost ratio for myrobalan dried in MIS2CD compared to TD. The MIS2CD's payback period is nearly 2.18 years, much less than the dryer's lifetime. [ABSTRACT FROM AUTHOR]

This article analyzes the processes of compressing hydrogen in the gaseous state, an aspect considered important due to its contribution to the greater diffusion of hydrogen in both the civil and industrial sectors. This article begins by providing a concise overview and comparison of diverse hydrogen-storage methodologies, laying the groundwork with an in-depth analysis of hydrogen's thermophysical properties. It scrutinizes plausible configurations for hydrogen compression, aiming to strike a delicate balance between energy consumption, derived from the fuel itself, and the requisite number of compression stages. Notably, to render hydrogen storage competitive in terms of volume, pressures of at least 350 bar are deemed essential, albeit at an energy cost amounting to approximately 10% of the fuel's calorific value. Multi-stage compression emerges as a crucial strategy, not solely for energy efficiency, but also to curtail temperature rises, with an upper limit set at 200 °C. This nuanced approach is underlined by the exploration of compression levels commonly cited in the literature, particularly 350 bar and 700 bar. The study advocates for a three-stage compression system as a pragmatic compromise, capable of achieving high-pressure solutions while keeping compression work below 10 MJ/kg, a threshold indicative of sustainable energy utilization. [ABSTRACT FROM AUTHOR]

The solar drying method consists of removing gartially and non-bound water with a small impact on the chemical structure and compositions, thus reducing the mass and minimizing the risk of numerous transformations. Taraxacum officinale leaves are well-known in the fields of pharmacology, herbal medicine, and traditional soft drinks. Since it is a seasonal plant, plants from these regions have become an indispensable element after drying and storing. The objective of this paper is to determine both total and specific energy consumption of the hybrid solar convection dryer in drying Taraxacum officinale leaves. The paper investigates the energy analysis of the leaves of Taraxacum solar drying, which includes the investigation of the impact of the aerothermal parameters' variations: 4 temperatures (50, 60, 70, and 80°C) and 2 drying airflows (150 and 300 m3 h–1) on the specific energy utilization in the drying process. Furthermore, this work studies the thermal efficiency as well as the energy efficiency of the solar dryer which gives room to maximize the performance of the dryer chamber. The results indicate minimal values of total energy consumption are achieved at higher temperatures and airflow rates. The findings reveal that lower total energy consumption is achieved at higher temperatures and airflow rates. Moreover, the study delves into thermal efficiency and energy efficiency, highlighting a thermal efficiency of approximately 5.58% at lower temperatures 50°C. [ABSTRACT FROM AUTHOR]

Electric vehicles (EVs) play a crucial role in tertiary sectors due to their eco-friendliness and sustainability when powered by clean energy. Integrating EV charging stations with renewable energy systems is essential to alleviate energy issues and grid pressure. Exploring this integration's feasibility is imperative for sustainable transportation. This study aims to provide a clear approach and methodology for examining the potential of integrating renewable energy technologies with EV charging stations at the district level. Additionally, the study investigates the energy, economic, and environmental benefits of an integrated system comprising photovoltaic/wind turbines (PV/WTs) connected to the electricity grid to meet the energy demand of a tertiary district consisting of five hotels in Egypt. Through the development of a simulation model, the paper verifies whether the proposed energy system can meet the district's energy demand. In addition, the simulation model has been employed to conduct a sensitivity analysis for investigating the impact of different charging rates on economic feasibility. The results indicate that a hybrid renewable energy system (HRES) integrated with an EV charging station can effectively relieve pressure on the electricity grid and provide electricity at competitive prices compared to the national grid. Moreover, the proposed energy system significantly reduces environmental emissions by up to 510 tons of CO2 per year and has the potential to decrease fossil fuel usage by 248 tons per year. Sensitivity analysis highlights the significant impact of charging prices on project profitability. [ABSTRACT FROM AUTHOR]

The development of high-rise buildings worldwide has given rise to significant concerns regarding their excessive electricity consumption. Among the various categories of high-rise structures, hotels used for business and conferences stand out as particularly extravagant in their energy use. The consequence arising from excessive energy usage is an escalation in carbon emissions, which is a primary driver of global warming. Therefore, this study aims to investigate the energy use intensity (EUI) of a hotel building located in Jakarta, Indonesia. In order to improve energy performance, this study explored various options for renovating the building envelope, such as incorporating insulation and a roof covering, as well as implementing building-integrated photovoltaics (BIPV). The building envelope renovations demonstrated a notable reduction in energy use by 15.8–27.7% per year. BIPV, such as curtain walls and double-skin façades, generated an energy use reduction of 4.8–8.6% per year. Remarkably, by combining the two approaches (i.e., adding insulation and a roof covering in the building envelope and adopting BIPV as double-skin façades), the potential reduction in energy use reached up to 32.2% per year. The findings can assist decision-makers in developing building renovation strategies for high-rise buildings while considering energy conservation. [ABSTRACT FROM AUTHOR]

The exploitation of renewable energy resources is an effective option to respond to climate change challenges. Wind energy can be exploited more efficiently and effectively than any other renewable energy source. By switching from onshore wind energy projects to offshore, the positive aspects of onshore wind energy remain and, at the same time, no valuable onshore area is occupied, while their efficiency (e.g., capacity factor) is increased. Greece has a rich wind potential and the maritime region of Thrace is one of Greece's maritime regions with the greatest potential for the development of offshore wind energy. The aim of the present paper is to identify the most appropriate sites for the deployment of offshore wind farms in the region of Thrace. The methodology includes (i) the delineation of the study area and the definition of the support structure of the wind turbine, (ii) the identification of seven (7) exclusion and fifteen (15) assessment criteria, (iii) the suitability analysis under five different zoning scenarios (equal weight, environmental, social, techno-economic, and researchers' subjective), and (iv) the micro siting and qualitative assessment of the most suitable sites based on energy, environmental, social, and economic criteria. The methodology is based on the combined use of Geographical Information Systems (GISs), specifically ArcGIS Desktop version 10.8.1, wind assessment software tools (WaSPs), specifically WaSP version 12.8, and multi-criteria decision-making methods. The results of the paper illustrate that the optimal suitability area that is proposed for offshore wind farm deployment is located at the easternmost end of the Greek part of the Thracian Sea. The planning and the deployment of offshore wind farm projects should follow a holistic and environmentally driven approach to ensure the integrity of all habitats and species affected. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization (HTC) has emerged as a pivotal technology in the battle against climate change and fosters circular economies. Operating within a unique reaction environment characterized by water as a solvent and moderate temperatures at self-generated pressures, HTC efficiently converts biomass residues into valuable bio-based products. Despite HTC's potential—from the management of challenging biomass wastes to the synthesis of advanced carbons and the implementation of biorefineries—it encounters hurdles transitioning from academic exploration to industrial implementation. Gaps persist, from a general comprehension of reaction intricacies to the difficulty of large-scale integration with wastewater treatments, to the management of process water, to the absence of standardized assessment techniques for HTC products. Addressing these challenges demands collaboration to bridge the many scientific sectors touched by HTC. Thus, this article reviews the current state of some hot topics considered crucial for HTC development: It emphasizes the role of HTC as a cornerstone for waste management and biorefineries, highlighting potentialities and challenges for its development. In particular, it surveys fundamental research aspects, delving into reaction pathways, predictive models, analytical techniques, and HTC modifications while exploring HTC's crucial technological applications and challenges, with a peculiar focus on combined HTC, wastewater integration, and plant energy efficiency. [ABSTRACT FROM AUTHOR]

The reciprocating plate column is a kind of column with the plates driven by a geared motor, and it has advantages in regard to efficiency compared to traditional columns in the extraction process, however, it comes with an increase in energy consumption. A new type of reciprocating plate column driven by electro-permanent magnet technology (EPM) is proposed in this paper to obtain a better performance with lower energy consumption. The feasibility and performance of the proposed column is studied by numerical simulation and experiments with a kerosene–water system. The electro-permanent magnet chuck could provide a maximum amplitude of 12 mm in this study. Kerosene was used as the dispersed phase, and deionized water was used as the continuous phase, in a laboratory-scale 35 mm diameter reciprocating plate column driven by EPM. Hydrodynamic performance experiments were carried out with different flowrates of both phases and reciprocating frequencies. The experimental results show that the electro-permanent magnet chuck, which serves as the driving device of the reciprocating plate column, plays the role of adding energy and increasing the droplet breakage. In addition, the energy consumption of the reciprocating plate column with traditional geared motor and electro-permanent magnet chuck is calculated respectively. Compared with the traditional geared motor, the energy saving of the electro-permanent magnet chuck is as high as 98.55%. [ABSTRACT FROM AUTHOR]

The urban environment represents one of the main contexts in which natural resources are exploited to support intensive human activities, especially from an energy perspective. In this context, there is still a lack of general methodologies/tools which can be used to understand the behavior of buildings and to prove their sustainability under real operating conditions, depending on their location, construction characteristics and materials, plants, external conditions, and conduction. In this research, the Buckingham theorem is applied to the thermophysics of buildings, describing the heat transfer of opaque surfaces in a transient regime. The abstraction of dimensionless numbers merges the main phenomena of interest, such as thermal conduction, convection, and radiation, enhanced by consideration of the surface sun–air temperature and the external air temperature. The parameters themselves were mutually matched through a proper equation, whose coefficients were determined by a regression analysis of the measurements from an intensive experimental campaign investigating a building in Florence for 3 years. The resulting correlation shows a good agreement with the available dataset and a determination coefficient of over 70%. Therefore, the proposed approach, owing to the generalization of the dimensionless numbers, suggests the possibility of sustainability estimates, from an energy point of view, of envelope/plant/user systems, including assessments at a higher scale than that of a single building. [ABSTRACT FROM AUTHOR]

The dynamic response characteristics between the multiple energy flows of electricity-hydrogen-heat in the renewable energy DC off-grid hydrogen production system are highly coupled and nonlinear, which leads to the complexity of its energy conversion and transmission law. This study proposes a model to describe the dynamic nonlinear energy conversion and transmission laws specific to such systems. The model develops a nonlinear admittance framework and a conversion characteristic matrix for multi-heterogeneous energy flow subsystems, based on the operational characteristics of each subsystem within the DC off-grid hydrogen production system. Building upon this foundation, an energy hub model for the hydrogen production system is established, yielding the electrical, thermal, and hydrogen energy outputs along with their respective conversion efficiencies for each subsystem. By discretizing time, the energy flow at each time node within the hydrogen production system is computed, revealing the system’s dynamic energy transfer patterns. Experiments were conducted using measured wind speed and irradiance data from a specific location in eastern China. Results from selected typical days were analyzed and discussed, revealing that subsystem characteristics exhibit nonlinear variation patterns. This highlights the limitations of traditional models in accurately capturing these dynamics. Finally, a simulation platform incorporating practical control methods was constructed to validate the model’s accuracy. Validation results demonstrate that the model possesses high accuracy, providing a solid theoretical foundation for further in-depth analysis of DC off-grid hydrogen production systems.

The objective of this study is to carry out a pre-feasibility study of solar industrial drying as a preliminary step before investing in large-scale solar drying projects in Algeria. Our primary goal is to promote the use of industrial solar dryers and to incite public authorities and industrials to invest in this promising niche. This work aims to strengthen the contribution of renewable energies and particularly solar energy in the sustainable development of the agri-food sector. Indeed, using solar energy will reduce the energy consumption and decrease greenhouse gas emissions of drying process. The prefeasibility analysis is achieved using the RETScreen Suite. Our study aims to investigate energy consumption of an industrial solar dryer of tomatoes, located in the city of Biskra. Various parameters as solar collector type and drying air temperature were tested and discussed. The obtained results showed a reduction in energy consumption up to 35%. Likewise, the reduction of GHG emissions recorded very favorable rates. This study's findings provide a preliminary vision for investors in the agri-food sector to build their project so they may maximize their profit while supporting the environment by lowering carbon emissions.

The direct expansion solar heat pump (DX-SHP) is a competent and sustainable option for domestic heating and drying applications. The solar collector-evaporator is a vital component of DX-SHP, which operates on solar energy and low-temperature ambient energy. The heat collection capacity, coefficient of performance, and evaporation temperature are used to quantify its performance. In this context, a systematic literature review on recent advancements in the collector-evaporator of DX-SHP is presented. This paper highlights and discusses the various configurations of solar collector-evaporators, theoretical and experimental investigations, and the selection method of eco-friendly refrigerants. The impact of different performance factors, such as ambient conditions, structural parameters, and types of refrigerants, on solar collector-evaporators is also reviewed. The optimal range for solar radiation, wind speed, and temperature is found to be 350 W/m2-700 W/m2, 0.5 m/s -2.5m/s, and 5°C to 35°C. The DX-SHP system produces hot water from 15°C to 60°C, with an average COP of 1.5 to 4.5. The finned solar collector-evaporator with R290 refrigerant performs optimally in various climatic conditions. Integrating solar collector-evaporators with innovative technologies such as microchannel, heat pipe, thermoelectric generators, photovoltaic thermal collectors with compound parabolic and Fresnel lenses can improve the system's performance. In this review, researchers can find scope for performance enhancement of the collector-evaporator used in DX-SHP.

This study presents the design, fabrication, and experimental analysis of Multiple Effect Distillation (MED) plant with four effects (4+C system). A total of 15 experiments were conducted, systematically categorized based on feed water temperature. Baby fire tube boiler producing 25 kg/h steam were installed with plant for experimental study. The investigation focused on distillate output, Gain Output Ratio, Overall Heat Transfer Coefficient, and the cost of distillate. Investigation demonstrates a notable increase in distillate output and Gain Output Ratio as the feed water temperature increases. Furthermore, improvements in the Overall Heat Transfer Coefficient with higher temperatures was observed. Notably, the cost of distillate decreased from $2.5/m³ to $1.5/m³ as the temperature increased. Findings suggest that 80 °C feed water temperature optimizes distillate output and Gain Output Ratio. Beyond this temperature, a decrease in distillate production occurs due to reduced latent heat of vaporization. The economic analysis reveals a trade-off between distillate output and cost, emphasizing the importance of optimizing feed water temperature. The inlet temperature was maintained at 115 ± 0.3 °C, while the boiler pressure remained at 5 bar. In the pilot plant configuration, MED system operating at 80 °C generated a daily water output of 438.93 L/day. The associated cost for producing fresh water was1.65 $/m3, and the system achieved a maximum Gain output ratio of 1.95.

The collection and use of Sargassum spp. as feedstock for the production of valuable products such as biomethane by anaerobic digestion (AD) would mitigate the negative impact of the blooms and the costs related to waste management in the Dominican Republic. In this work, the effect of the particle size of pelagic Sargassum spp. biomass, as a result of mechanical pretreatments, on the biomethanation was determined. The granulometric analysis of the mechanically pre-treated biomass was carried out using a Mastersize2000. The Biochemical Methane Potential (BMP) of the samples was determined using an Automatic Potential System Test II (AMPTS® II). The kinetic parameters of the reaction were scientifically evaluated by using First order kinetic Model and modified Gompertz Model. The granulometric analysis showed a monomodal distribution on crushed biomass (505 µm) and a bimodal distribution on the milling sample (107 µm). The bimodal biomass means the biomass is characterized by the presence of fine and large particles. We observed that BMP increased by 78.85% when particles were reduced from 50,000 µm to 505 µm and by 73.61% when particles were reduced from 50,000 µm to 107 µm. A low methane yield from the milling biomass (107 µm) compared to the crushed biomass (505 µm) could be related to the excessive reduction of particle size. The fine particles are subject to the formation of aggregates and consequently, the contact area between the algae cells and the microorganisms that operate the anaerobic digestion process decreases.

Lunar base construction is a crucial component of the lunar exploration program, and considering the dynamic characteristics of lunar soil is important for moon construction. Therefore, investigating the dynamic properties of lunar soil by establishing a constitutive relationship is critical for providing a theoretical basis for its damage evolution. In this paper, a split Hopkinson pressure bar (SHPB) device was used to perform three sets of impact tests under different pressures on a lunar soil simulant geopolymer (LSSG) with sodium silicate (Na2SiO3) contents of 1%, 3%, 5% and 7%. The dynamic stress–strain curves, failure modes, and energy variation rules of LSSG under different pressures were obtained. The equation was modified based on the ZWT viscoelastic constitutive model and was combined with the damage variable. The damage element obeys the Weibull distribution and the constitutive equation that can describe the mechanical properties of LSSG under dynamic loading was obtained. The results demonstrate that the dynamic compressive strength of LSSG has a marked strain-rate strengthening effect. Na2SiO3 has both strengthening and deterioration effects on the dynamic compressive strength of LSSG. As Na2SiO3 grows, the dynamic compressive strength of LSSG first increases and then decreases. At a fixed air pressure, 5% Na2SiO3 had the largest dynamic compressive strength, the largest incident energy, the smallest absorbed energy, and the lightest damage. The ZWT equation was modified according to the stress response properties of LSSG and the range of the SHPB strain rate to obtain the constitutive equation of the LSSG, and the model's correctness was confirmed.

Abstract This study extensively examined the impact of aluminium oxide (Al2O3) and titanium dioxide (TiO2) nanoparticles addition in the biodiesel fuel derived from Guizotia abyssinica (L.) oil. The assessment of fuel blends, which were created by combining nanoparticles and biodiesel was conducted using energy, exergy, and sustainability indices. The highest recorded power output of 2.81 kW was observed for the GAB20A engine operating at 1800 rpm. The experimental results revealed that the GAB20A exhibited the lowest fuel consumption, with a recorded value of 203 g/kWh, when operated at 1600 rpm among all the tested blend fuels. The blend GAB20A exhibited the highest level of energy efficiency at 1600 rpm of 29.5%, as determined by the study. Simultaneously, it was observed that GAB20 exhibited the lowest energy efficiency at 1200 rpm among all the blend fuels at 25%. The emission levels of nitrogen oxides (NOx) and carbon monoxide (CO) were observed to be quite low, although a little rise in carbon dioxide (CO2) was detected. For validation of results the artificial neural network (ANN) was used and an average of 1.703% difference in energy efficiency, 2.246% decrease in exergy efficiency, and 1.416% difference in sustainability index was found.

Date fruit drying is a process that consumes a significant amount of energy due to the long duration required for drying. To better understand how moisture flows through the fruit during drying and to speed up this process, drying studies must be conducted in conjunction with mathematical modeling, energy analysis, and environmental economic analysis. In this study, twelve thin-layer mathematical models were designed utilizing experimental data for three different date fruit varieties (Sakkoti, Malkabii, and Gondaila) and two solar drying systems (automated solar dryer and open-air dryer). These models were then validated using statistical analysis. The drying period for the date fruit varieties varied between 9 and 10 days for the automated solar dryer and 14 to 15 days for open-air drying. The moisture diffusivity coefficient values, determined using Fick's second law of diffusion model, ranged from 7.14 × 10−12 m2/s to 2.17 × 10−11 m2/s. Among the twelve thin-layer mathematical models, we chose the best thin drying model based on a higher R2 and lower χ2 and RMSE. The Two-term and Modified Page III models delivered the best moisture ratio projections for date fruit dried in an open-air dryer. For date fruit dried in an automated solar dryer, the Two-term Exponential, Newton (Lewis), Approximation diffusion or Diffusion Method, and Two-term Exponential modeling provided the best moisture ratio projections. The energy and environmental study found that the particular amount of energy used varied from 17.936 to 22.746 kWh/kg, the energy payback time was 7.54 to 7.71 years, and the net CO2 mitigation throughout the lifespan ranged from 8.55 to 8.80 tons. Furthermore, economic research showed that the automated solar dryer's payback period would be 2.476 years. [ABSTRACT FROM AUTHOR]

Particle tuned mass damper has received considerable attention on mitigating structural seismic responses recently. However, soil-structure interaction effects have not been considered for the optimization design of particle tuned mass damper in the previous studies yet, which may play significant roles in particle tuned mass damper's effectiveness. This paper investigates the seismic control performance of particle tuned mass damper for tall buildings considering SSI effects. A 40-story benchmark structure is adopted as the primary structure, and different soil conditions including soft, medium, dense soil, and the fixed-base case are considered. Based on the Cuckoo Search algorithm, an optimum design approach for the particle tuned mass damper implemented in SSI system under earthquake excitations is proposed, and the optimum parameters of particle tuned mass damper are obtained from the optimum design process. The optimum results indicate that the optimized particle tuned mass damper can effectively decrease the displacement response without the increase of peak acceleration, and the reduction rates could exceed 30% in some cases. Compared with other soil type cases, under soft soil condition, the optimum parameters of particle tuned mass damper are especially different, and the mitigation effects of the optimized particle tuned mass damper on maximum displacement weaken. Hence, it is necessary to consider the SSI effects for particle tuned mass damper's seismic design. Furthermore, the interaction effects between the primary structure and particle tuned mass damper in SSI system are also evaluated through energy analysis. The results show that considering SSI effects, the optimized particle tuned mass damper device dissipates the overwhelming majority of the input energy, and it greatly decreases the structural energy, displaying excellent energy dissipation performance on seismic vibration control of structure. [ABSTRACT FROM AUTHOR]

In order to evaluate the damage deterioration degree of freeze–thaw rock under in-situ stress in cold area engineering, it is necessary to establish the triaxial compression damage constitutive model and study on meso-failure characteristics of freeze–thaw rock. The triaxial compression tests under confining pressure of 3 MPa, 5 MPa, and 10 MPa were carried out on saturated sandstone after 0, 20, 40, and 60 freeze–thaw cycles. The results show that with the increase of freezing–thawing times, the peak deviatoric stress and elastic modulus under the same confining pressure decrease gradually, and increase gradually with the increase of confining pressure. The triaxial compression damage constitutive model of freeze–thaw rock was established based on the dissipation energy ratio and the principle of minimum energy dissipation. Based on this model, the evolution law of energy ratio in different stages of compression process was studied, and the influence characteristics of confining pressure and freeze–thaw on rock failure were analyzed. PFC2D was used to establish the numerical method on triaxial compression of frozen-thawed rock and determine the calculation parameters. The energy evolution law and the number growth law of different cracks in the triaxial compression process of frozen-thawed rock were studied. It is found that the energy value at the peak and the ratio of tensile crack to shear crack decrease with the number of freezing–thawing cycles. Meanwhile, the characteristics of freezing–thawing cycles promoting the shear failure of rock were clarified. [ABSTRACT FROM AUTHOR]

In the context of the global energy crisis and environmental shifts, solar energy, recognized for its cleanliness and renewability, has increasingly captured attention in the application within the architectural sector. As a significant portion of energy consumption, the electrification of buildings and their transformation towards green systems are crucial for energy saving and emission reduction. With technological advancements, solar-powered building electrical systems have emerged as a focal point of research. The core issues affecting their widespread application are the system's thermodynamic efficiency and integration strategies. Despite advancements in solar cell efficiency and device-level optimization, there remains a deficiency in system-level thermodynamic analysis and integrated optimization, limiting the efficiency and practicality of solar energy in construction. This study initiates with an energy and exergy analysis to delve into the thermodynamic efficiency of solar-powered building electrical systems, clarifying the efficiency of energy conversion and the irreversibility losses. Building on these findings, strategies for system integration and operational optimization are proposed, aiming for a comprehensive optimization of solar systems through the establishment of targeted design and operational standards. This research not only provides a theoretical foundation for enhancing the energy efficiency of solar systems but also offers practical guidance for designing and managing efficient, sustainable building electrical systems. [ABSTRACT FROM AUTHOR]

Today's product development is challenged with redesigning products into more sustainable variants while maintaining economic and technical feasibility. Among the ways to address this, lightweight design offers numerous opportunities to increase the product's resource efficiency while reducing emissions and emerging life cycle costs. However, this requires advanced analysis concepts to be applied in the early phase of development to efficiently allocate engineering capacities and to subsequently exploit environmental sustainability potentials in the best possible way. Therefore, the present work contrasts two lightweight design methods: the 'extended target weighing approach' (ETWA) and the 'functional life cycle energy analysis' (FLCEA). Based on the use case of the generation development of a semi-mobile handling system, their respective strengths, and weaknesses for a sustainable life cycle engineering are highlighted. While the widely known ETWA focuses on three coupled impact categories (mass, costs, and CO2 emissions), the novel FLCEA method only addresses the mass-related energy consumptions, albeit more detailed across three life cycle stages. As a result of it, the application effort can be decreased, while on the one hand the meaningfulness for the environmental sustainability effects of design changes remains unaltered and, on the other hand, the derivation of recommendations for action is facilitated. [ABSTRACT FROM AUTHOR]

Copyright of FME Transactions is the property of University of Belgrade, Faculty of Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sustainable aviation fuel (SAF) production from captured carbon dioxide and green hydrogen, is referred to as the key to decarbonize the hard-to-abate aviation sector. Fischer-Tropsch is a mature and reliable pathway for hydrocarbon synthesis, with a wide spectrum of technological options and high plant efficiency extending to more than 80 % of e-kerosene selectivity. In this work, an Aspen Hysys model, coupled with different Matlab simulations for Fischer-Tropsch, Hydrocracker and SOEC, was set up to estimate efficiency and selectivity. The results show that global efficiency is mainly linked to the efficiency of the production of H 2. Energetic efficiency reaches 48.06 % using the already existing commercial electrolyte supported cell in a SOEC electrolyser, but it could increase to 65.74 % if cathode supported cell was considered. • An energy analysis of the Power-to-Liquid process has been performed. • The system reaches a global efficiency of 48.06 % and up to 38.71 % of Power-to-Kerosene efficiency. • It is possible to increase global efficiency up to 65.74 % and Power to kerosene efficiency to 53.60 %. [ABSTRACT FROM AUTHOR]

The Renewable Energy Directive II introduces renewable energy communities, enhancing energy sharing. However, many existing initiatives, focussing only on electricity, overlook the substantial energy demand in building sector comprising residential and commercial spaces. Energy communities in this sector can leverage district heating and cooling technology for thermal energy sharing, contributing to carbon neutrality by enhancing efficiency and reducing primary energy usage. Advanced strategies such as integrating renewables into heating and cooling grids, sector coupling, and utilising waste heat are key in moving away from fossil fuels. The Campania Region (Italy), abundant in geothermal energy potential, chose a district in which to implement the GeoGRID system. This innovative setup combines a four-pipe district heating and cooling network with an Organic Rankine Cycle plant, tapping into geothermal energy from the Solfatara area. The geothermal fluid's heat feeds the ORC evaporator and then powers the thermal network, allowing direct heating and domestic hot water supply during winter. A thorough techno-economic analysis assessed the energy potential extractable from the geothermal fluid. Crucial aspects of this study are the evaluation of the energy and environmental efficiency of the system within the renewable energy community framework. Additionally, the paper introduces a methodology applicable for assessing geothermal energy communities on a global scale. [ABSTRACT FROM AUTHOR]

The world's population is expected to increase by nearly two billion in the next 30 years; the population will increase from 8 billion to 9.7 billion by 2050 and could peak at 10.4 billion by the mid-2080s. The extreme weather triggered by global climate change has severely hit crop yields in open-field cultivation and led to an increase in food prices. Furthermore, in the last few years, emergency events such as the COVID-19 pandemic, wars/conflicts, and economic downturns have conditioned agricultural production and food security around the world. Greenhouses could be efficient cultivation systems because they enable food production in a sustainable way, limiting contact between pollutants and plants and optimizing the use of water, energy, and soil. This paper proposes a novel dome-soilless greenhouse concept for tomato cultivation in the Mediterranean area. The proposed greenhouse is fixed on a sea platform to take advantage of the seawater cooling environment and to integrate water consumption into a hydroponic system. In order to evaluate the best covering solution material to adopt, a few thermal and photometric characteristics of greenhouse covering materials were evaluated using a simplified method. A dynamic simulation was carried out to compare the proposed seawater cooling system with a conventional cooling tower in terms of the electric energy spent to maintain the inside temperature range at 13–25 °C across all seasons in the year. The proposed heating, ventilation, and air conditioning (HVAC) system allowed a total annual energy saving of more than 10%. The energy saved was a result of the better cooling performance of the seawater heat exchange that allowed energy saving of about 14% on cooling. The comparison between the model characterised by a 6 mm polycarbonate coupled with UbiGro film and a seawater cooling system, and the model including a 6 mm polycarbonate coupled with a clarix blue film covering and a tower cooling system highlighted energy saving of about 20%. The obtained results indicate possible future directions for offshore greenhouses to carry out independent production together with the integration of photovoltaic modules, water treatment plants, and smart remote-control systems. [ABSTRACT FROM AUTHOR]

Resilience is a functional attribute of shield tunnels to ensure continued serviceability. From the performance-based perspective, the concept of deformational resilience is proposed and defined as the ability to resist deformation development (robustness) and the ability to recover from pre-existing deformation (recoverability). This work aims to measure the deformational resilience of shield tunnel lining structure, targeting at its most vulnerable part—longitudinal joint. For this purpose, a series of full-scale tests are carried out to perform 1) the failure process to simulate external surcharge loads, 2) the recovery process to simulate the effects of unloading and tunnel bilateral soil grouting, and 3) the cyclic loading process to simulate incremental cycling loading and unloading conditions. The assessment of deformational resilience is based on joint opening from the tests and related structural energy analysis. The test results demonstrate that the capability of tunnel longitudinal joint to resist deformation deteriorates with increasing overload level, and the recovery efficiency of joint opening presents nonlinear degradation with the increase of pre-existing deformation. The deformational resilience of longitudinal joint revealed in this research can facilitate the selection of appropriate timing and optimal design of technical parameters related to recovery measures for over-deformed shield tunnels. [ABSTRACT FROM AUTHOR]

Autoclave devices are used to perform high‐temperature sterilization processes under pressure. Autoclaves can be integrated with an absorption refrigeration cycle to utilize the waste heat generated at high temperature during the process. Today, many studies are carried out on the evaluation of energy resources. In this study, it is designed to obtain a cooling load by adding an integrated sub‐cycle to the waste steam heat of the autoclave device in a sterilization unit. In the lower cycle, the ammonia/water absorption refrigeration cycle is used. According to the energy analysis; With the condition that the cooling temperature is 7°C, the generator temperature of 95°C and a cooling load of 130.9 W occurred with 531.7 W of waste heat received by the absorption cooling system. Accordingly, an efficiency of COP 0.246 was obtained. The energy analysis of the absorption refrigeration cycle can improve the energy efficiency of the autoclave and save energy. In addition, the obtained cooling load will be preserved in medical supplies that need to be kept cold. [ABSTRACT FROM AUTHOR]

The Yellow River Delta (YRD) stands as a globally significant wetland, playing a pivotal role in sustaining regional ecosystem stability and offering crucial ecosystem services to humanity. However, anthropogenic activities, particularly resource development, unavoidably disrupt the ecosystem, leading to the degradation of these vital services. Utilizing satellite remote sensing data, the InVEST model, and energy analysis, this study introduces the concept of 'emergy' as an 'intermediate variable' to investigate the spatiotemporal changes in the ecosystem service value of the YRD. Five distinct types of ecosystem services are selected for quantitative assessment and analysis of the YRD's spatiotemporal evolution from 1990 to 2020. Results indicate a 63.7% decline in the total value of ecosystem services from 1990 to 2010, followed by a 16.5% increase from 2010 to 2020. The study also unveils spatial shifts in high- and low-value areas of ecosystem services and attributes these changes to rapid urbanization and alterations in land use and cover. The assessment of ecosystem service values concretizes the intangible ecosystem service functions of natural resources. This lays the foundation for establishing a mechanism that combines positive incentives and reverse pressure to achieve the economic valuation of ecosystem service. [ABSTRACT FROM AUTHOR]

This research article delves into the comprehensive assessment of the energy and exergy efficiencies of two distinct solar photovoltaic (PV) panel technologies—olycrystalline and monocrystalline–deployed in the climatic context of Skikda, Algeria. The study aims to discern the superior performer among these two-panel types while taking into account the influential factors of solar radiation, and wind velocity. The results reveal that both panel technologies exhibit closely matched energy and exergy efficiencies, with a slight preference observed for monocrystalline panels. The impact of environmental variables on panel performance is significant, with temperature negatively affecting efficiency, while increased solar irradiance positively enhances energy and exergy production. Wind speed plays a cooling role, thereby augmenting electrical energy generation for both panel types. These findings contribute valuable insights into optimizing solar energy utilization in regions with warm and sun-drenched climates, like Skikda. The research serves as a crucial reference point for policymakers, researchers, and industry stakeholders keen on harnessing solar energy effectively under varying environmental conditions. [ABSTRACT FROM AUTHOR]

The collection and use of Sargassum spp. as feedstock for the production of valuable products such as biomethane by anaerobic digestion (AD) would mitigate the negative impact of the blooms and the costs related to waste management in the Dominican Republic. In this work, the effect of the particle size of pelagic Sargassum spp. biomass, as a result of mechanical pretreatments, on the biomethanation was determined. The granulometric analysis of the mechanically pre-treated biomass was carried out using a Mastersize2000. The Biochemical Methane Potential (BMP) of the samples was determined using an Automatic Potential System Test II (AMPTS® II). The kinetic parameters of the reaction were scientifically evaluated by using First order kinetic Model and modified Gompertz Model. The granulometric analysis showed a monomodal distribution on crushed biomass (505 µm) and a bimodal distribution on the milling sample (107 µm). The bimodal biomass means the biomass is characterized by the presence of fine and large particles. We observed that BMP increased by 78.85% when particles were reduced from 50,000 µm to 505 µm and by 73.61% when particles were reduced from 50,000 µm to 107 µm. A low methane yield from the milling biomass (107 µm) compared to the crushed biomass (505 µm) could be related to the excessive reduction of particle size. The fine particles are subject to the formation of aggregates and consequently, the contact area between the algae cells and the microorganisms that operate the anaerobic digestion process decreases. [ABSTRACT FROM AUTHOR]