Water Desalination System Research Articles

Multi-objective optimization and comprehensive Thermodynamic, economic, and environmental analysis of an innovative solar-geothermal integrated system for synergistic power generation and water desalination

ABSTRACT This paper presents a novel multi-objective optimization and sustainability analysis framework for an innovative solar-geothermal integrated system for power generation and water desalination. Harnessing renewable solar and geothermal energy, the system offers a sustainable solution for energy, water, and environmental challenges. Advanced thermodynamic modeling techniques, validated by industry simulations, accurately characterize system performance. Departing from conventional analyses, the research incorporates exergy-based economic and environmental assessments and the emergy concept to quantify the total available energy required, enabling a comprehensive sustainability evaluation. Through multi-objective optimization using genetic algorithms, the system’s design and operational parameters are optimized to enhance exergy efficiency, economic emergy performance, and environmental emergy performance simultaneously. The optimization framework considers turbine inlet conditions, pressures, and desalination configurations to identify optimal operating points balancing energy efficiency, economic feasibility, and environmental impact. Results demonstrate significant improvements of up to 23.49% in exergy efficiency, 25.97% in economic emergy performance, and 16.04% in environmental emergy performance compared to the baseline system. This study focuses on the multi-objective optimization of a novel solar-geothermal integrated system for synergistic power generation and water desalination. The methodology combines thermodynamic, economic, and environmental analyses to evaluate system performance. Key findings include a significant improvement in overall efficiency and sustainability compared to conventional systems, highlighting the potential for large-scale implementation.

Investigating different scenarios of integrating solar-assisted carbon capture with combined cycle power plant and water desalination system

In this work, an optimal algorithm-based integration of solar thermal energy with carbon capture and desalination processes were proposed. The stripper columns, identified as the most energy-consuming equipment, were designed with constant capacities to ensure practicality and applicability. Results show that, without affecting the power plant's efficiency, using a solvent tank as an energy storage system (scenario-2) increases total CO2 capture from 45 % to 98 % compared to a part-time solar power system (scenario-1). Utilizing two solvent tanks reduces waste energy from 87 % to 67 % (scenario-3), while achieving 100 % CO2 capture. Using three different stripper columns (scenario-4) lowers the levelized cost of energy by 20 %. Incorporating an additional multiple effect distillation system (scenario-5) reduces levelized cost of energy and energy loss by 26 % and 74 %, respectively. Approximately 28 % of the total solar energy collected (4.64 × 106 MWh) was used to capture 1.57 × 106 ton.year−1 of CO2. The remaining energy was used in desalination to produce 9.4 × 106 m³.year−1 of fresh water, increasing overall energy efficiency from 28 % to 81 %, and reducing waste energy to 0.88 × 106 MWh, just 26 % of previous scenarios' waste.

Productivity, energy, and exergy analyses of a water desalination system-based vortex tubes with different configurations: An experimental implementation

The present implementation explores the use of vortex tubes (VTs) as an alternative thermal technology for water desalination systems (WDSs). VTs are utilized to provide hot air for evaporating salt water in the evaporator, while simultaneously supplying cold air to condense the water vapor in the condenser. The study investigates the influence of a number of operating parameters, including inlet water temperature (Ti,w), cold mass ratio (CR), and vacuum pressure (pvac) on the performance of WDS-based VTs through experimental analysis. Different configurations of VTs are tested for WDS applications, including WDS-based single vortex tube (VT), WDS-based two series vortex tubes (2SVTs), and WDS-based two parallel vortex tubes (2PVTs). Performance metrics such as the evaporation heat (QEvap), desalinated water production (DWP), gain output ratio (GOR), and exergy performance are evaluated for each configuration. Results show that the WDS-based 2SVTs exhibits the highest QEvap; while the WDS-based 2PVTs demonstrates the lowest value. Correlations are proposed to predict DWP for different configurations of WDS based on pvac, Ti,w, and CR with a maximum deviation of ±12.2 %. Furthermore, the WDS-based 2SVTs achieves the best GOR of 2.5 at an inlet water temperature of 80 °C, representing a significant improvement compared to the WDS-based VT and 2PVTs. The exergy efficiency (ηex) increases with higher CR, and the WDS-based 2SVTs ensures the best exergy performance, and its maximum overall ηex equals 78.2 %.

Evaluation of suitable sites for concentrated solar power desalination systems: case study of Mauritania

It is imperative to address the critical problem of water scarcity in sub-Saharan Africa, especially in light of the aggravating effects of climate change brought on by the extraction of fossil fuels. In order to ensure the availability of drinkable water in these places, this research proposes integrating concentrated solar power (CSP) with desalination systems (DS). Present research is focused on identifying and evaluating potential locations for DS/CSP implementation within Mauritania by employing a comprehensive, multi-criteria decision-making framework. This framework synthesizes mathematical approaches from multi-criteria analysis with geospatial analysis techniques, considering a range of factors including environmental impact, economic viability, demographic demands, and climatic conditions. Research findings reveal that 10% of the Mauritanian, approximately 103070 km2, presents optimal conditions for the deployment of DS/CSP facilities. The study delineates the coastal regions as prime candidates for seawater desalination plants, while the densely populated southeastern areas are identified as suitable for brackish water desalination systems. Conversely, the less inhabited northern territories hold the potential for decentralized brackish water desalination plants. Hence this study provides a holistic approach for DS/CSP systems installation to manage water scarcity as well as energy security issues in Mauritania. And also provides basis for formulating future policies in the region.

Deep learning with improved hybrid neuro-turning for predictive control of flux based on experimental DCMD module design of water desalination system

This study explores two scenarios for optimizing the predictive control of flux in water desalination systems: experimental design of direct contact membrane distillation (DCMD) and artificial intelligence (AI) models. Deep learning networks, specifically Long Short-Term Memory (LSTM), and standalone AI models, including hybrid Adaptive Neuro-Fuzzy Inference System (ANFIS) and Artificial Neural Network (ANN), were evaluated. Evaluation criteria, along with 2D graphical visualization, were used to assess model accuracy. ANFIS-C4 emerged as the standout model, achieving perfect predictive skills with 100 % accuracy and low RMSE of 0.0522 in the training phase, and maintaining high performance in testing with 99.73 % accuracy and RMSE of 0.7121. Similarly, ANN-C4 demonstrated near-perfect accuracy with 100 % accuracy and RMSE of 0.0643 in the training phase and also maintained excellent performance in the testing phase. Despite requiring multiple inputs, ANFIS and ANN show remarkably high capability in predictive accuracy. Among LSTM models, LSTM-C3 achieved the highest training DC of 91.35 %, indicating robust performance in capturing training data variability. LSTM-C2 showed superior generalization with a testing DC of 0.8539, despite using only two input parameters. The narrow distribution of predicted values around the median in violin plots for ANFIS-C4 and ANN-C4, along with their low RMSE, validates their superior performance. The exceptional results of ANFIS-C4 and ANN-C4 highlight their potential in water desalination applications, supporting Sustainable Development Goal 6 (SDGs-6) and Environmental Protection Agency (EPA) objectives for sustainable water management. This research underscores the importance of advanced computational models in enhancing the efficiency and reliability of water desalination systems, contributing to global efforts in sustainable water resource management.

A theoretical characterization of osmotic power generation in nanofluidic systems

Water desalination and fluid-based energy harvesting systems utilize ion-selective nanoporous materials that allow preferential transport of ions that are oppositely charged to the surface charge, resulting in the creation of an electrical current. The resultant current forms due to a potential drop or a concentration gradient (or both) applied across the system. These systems are electrically characterized by their current-voltage, I−V\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$I-V$$\\end{document}, response. In particular, there are three primary characteristics: the ohmic conductance, GOhmic=I/V\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${G}_{{{{{\\rm{Ohmic}}}}}}=I/V$$\\end{document}, the zero-voltage current, IV=0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${I}_{V=0}$$\\end{document}, and the zero-current voltage, VI=0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${V}_{I=0}$$\\end{document}. To date, there is no known self-consistent theory for these characteristics. Here, we present simple self-consistent expressions for each of these characteristics that provide remarkable insights into the underlying physics of water desalination and energy harvesting systems. These insights can be used to interpret (and reinterpret) the numerical and experimental measurements of any nanofluidic system subject to an arbitrary concentration gradient as well as improve their design.

Artificial Neural Network-Based Real-Time Power Management for a Hybrid Renewable Source Applied for a Water Desalination System

Water desalination systems integrated with stand-alone hybrid energy sources offer a remarkable solution to the water–energy challenge. Given the complexity of these systems, selecting an appropriate energy management system is crucial. In this regard, employing artificial intelligence techniques to develop and validate an energy management system can be an effective approach for handling such intricate systems. Therefore, this paper presents an ANN-based energy management system (ANNEMS) for a pumping and desalination system connected to an isolated hybrid renewable energy source. Thus, a parametric sensitivity algorithm was developed to identify the optimal neural network architecture. The water–energy management-based supervised multi-layer perceptron neural network demonstrated effective power sharing within a short time frame, achieving accuracy criteria of RMSE, R, and R² between the actual and estimated electrical power of the three motor pumps. The ANNEMS is defined to facilitate real-time power sharing distribution among the various system motor pumps on the test bench, considering the generated power profile and water tank levels. The proposed strategy employs power field oriented control to maintain DC bus voltage stability. Experimental results from the implementation of the proposed ANNEMS are provided. Therein, the power levels of the three motor pumps demonstrated consistent adherence to their reference values. In summary, this study highlights the significance of selecting appropriate energy management for real-time experimental validation.

Performance modeling and cost optimization of a solar desalination system using forward osmosis with energy storage

This study presents the design and performance evaluation of a solar-driven water desalination system based on forward osmosis (FO) with thermally responsive ionic liquids (ILs). FO is a two-step process involving dilution of the ILs with water, followed by heating above a critical temperature to induce phase separation of liquid water from the IL. This regeneration step can be achieved by integrating FO with low-grade solar energy, which is abundant in regions that face severe water scarcity. A system design is presented that couples an FO membrane module with a compound parabolic concentrator solar collector and thermal energy storage to minimize solar intermittency and produce clean water at a distributed scale of 10 m3/day. To determine the optimal sizing of components in the system, a technoeconomic analysis using the TRNSYS software is performed with the goal of minimizing the levelized cost of water (LCOW). Notably, over 96 % of the energy required for regeneration comes from solar energy and/or the thermal energy storage (TES) in all cases, with auxiliary heat from electricity being used to maintain a continuous process. To evaluate the potential of solar-FO in three different locations within the United States, a case study is presented for Phoenix, AZ; San Diego, CA; and Atlanta, GA. The simulation results reveal that for a small-scale desalination system, LCOW values as low as $1.31/m3 can be attained, with the potential to approach $1/m3 by lowering the costs of the solar collector and FO module based on a sensitivity analysis.

Putting stored hydrogen to work without consuming it: A flexible system for energy conversion and water desalination

We report a flow battery that utilises hydrogen as a charge carrier in both the cathode and anode and makes use of the energy released in acid-base neutralisation to desalinate seawater and generate electricity, based on cheap and relatively safe electrolytes stored externally. We demonstrate desalination of simulated seawater from 0.6 to 0.009 ± 0.005 M NaCl and successful removal of Na+, K+, Mg2+, and Ca2+ from real seawater to potable levels. The battery can also be used for osmotic energy conversion through reverse electrodialysis (RED) if the acid and base are substituted by neutral diluted aqueous solution (e.g., freshwater), reaching power densities similar to state-of-the-art systems while using a much more environmentally friendly redox charge carrier, namely hydrogen, than those common in RED systems. The most important characteristics of the reported system are (i) its flexibility, which allows easy tuning to favour either energy generation or degree of desalination by changing the flow rates and volumes of each individual channel and/or the discharge current and (ii) the possibility of putting hydrogen to work without consuming it while stored for later shipment, thereby producing a profit that can contribute to decreasing the cost of green hydrogen.

Heat recovery of multistage circulated permeate gap membrane distillation for energy-efficient water production

Addressing the challenges of energy efficiency in the desalination industry, this study proposed an energy-efficient water desalination system, focusing on the novel innovative approach of gap water circulation in permeate gap membrane distillation (PGMD) systems. A counterflow multistage is considered and analyzed using combined heat-mass transfer modeling. In comparison to conventional PGMD configurations, the introduction of gap water circulation has visibly emerged to increase water productivity while decreasing energy consumption. This research systematically explored the impact of this innovation, employing a comprehensive methodology that includes modifying flow chamber configurations and analyzing operational parameters. The study was performed at different seawater intake flow rates, intake temperature, feed injection temperature, and different number of stages. It was found that increasing the number of stages in the counterflow configuration presented better energy efficiency and higher feed recovery ratios at different conditions. A remarkable reduction in Specific Thermal Energy Consumption (STEC) to 92 kWh/m3, coupled with a notable increase in flux values reaching 28 kg/m2.hr for the alternative modules due to the intensified turbulence and mixing. The study demonstrated the potential of gap water circulation in significantly enhancing the energy efficiency and productivity of MD systems compared to conventional PGMD systems.

Basil seed hydrogel incorporated activated carbon as a Capable, Bio-Based, and Cost-Effective interfacial solar steam generator

Utilization of solar energy for desalination and purification of seawater opens up a state-of-the-art way to meet the water needs all around the world specially in coastal cities. Herein, the eco-friendly, low cost and bio-based basil seed (BS) hydrogel is combined with activated carbon (AC) to synthesize activated carbon merged with basil seed hydrogel (AC-BS) composite material. Due to the photothermal property of the AC, the AC-BS composite was used to design an interfacial solar steam generator (ISSG) for water purification. The AC absorbs the sunlight and converts it to the required heat needed for water evaporation and the superhydrophilic BS hydrogel supplies water to the surface causing the high salt rejection ability of the system, in addition, it decreases the required energy for evaporation. The AC-BS is characterized using characterization methods such as EDX and FESEM. The two-dimensional (2D) AC-BS system containing a cotton fiber used to transfer water from the bulk to the surface, a layer of styrofoam as a heat insulator and AC-BS on the surface shows evaporation rate of 1.93 kg m−2h−1. The three-dimensional (3D) AC-BS, designed to solve the solar irradiation angle fluctuation problem during a day and seasons, shows an evaporation rate of 2.70 kg m−2h−1 and an efficiency of about 91 % under 1 sun illumination. The ability of the AC-BS system for saline water desalination and waste water-contaminated dyes as a pollutant treatment is highly acceptable. The AC-BS ISSG can be studied and used on large scales to provide fresh water from saline water.

Integration of IoT Technologies for Enhanced Monitoring and Control in Hybrid-Powered Desalination Systems: A Sustainable Approach to Freshwater Production

In the face of our rapidly expanding global population, the necessity of meeting the fundamental needs of every individual is more pressing than ever. Human survival depends upon access to water, making it a vital resource that demands novel solutions to ensure universal availability. Although our planet is abundant in water, 97.5% of it is saltwater, compelling nations to investigate ways to make it suitable for consumption. Seawater desalination is becoming increasingly vital for water sustainability. While seawater desalination offers a solution, existing methods often grapple with high energy consumption and maintaining consistent water quality. This paper proposes a novel hybrid water desalination system that addresses these limitations. Our system leverages solar energy, a readily available renewable resource, to power the desalination process, significantly improving its environmental footprint and operational efficiency. Additionally, we integrated a network of sensors and the Internet of Things (IoT) to enable the real-time monitoring of system performance and water quality. This allows for the immediate detection and improvement in any potential issues, ensuring the consistent production of clean drinking water. By combining solar energy with robust quality control via IoT, our hybrid desalination system offers a sustainable and reliable approach to meet the growing demand for freshwater.

Functional and financial analysis of an inclined step solar desalination using phase change nanomaterials.

Recent decades have seen a shortage of water, which has led scientists to concentrate on solar desalination technologies. The present study examines the solar water desalination system with inclined steps, while considering various phase change materials (PCMs). The findings suggest that the incorporation of PCM generally enhances the productivity of the solar desalination system. Additionally, the combination of nanoparticles has been used to PCM, which is a popular technique utilized nowadays to improve the efficiency of these systems. The current investigation involves the transient modeling of a solar water desalination system, utilizing energy conservation equations. The equations were solved using the Runge-Kutta technique of the ODE23s order. The temperatures of the salt water, the absorbent plate of the glass cover, and the PCM were calculated at each time. Without a phase changer, the rate at which fresh water is produced is around 5.15 kg/m2·h. The corresponding mass flow rates of paraffin, n-PCM I, n-PCM III, n-PCM II, and stearic acid are 22.9, 28.9, 5.9, 11.9, and 73 kg/m2·h. PCMs, with the exception of stearic acid, exhibit similar energy efficiency up to an ambient temperature of around 29°. However, at temperatures over 29°, n-PCM II outperforms other PCM.

Energetic, exergetic, exergoeconomic, and enviroeconomic analysis of solar dish-integrated water desalination system with various nanofluids

Global demand for freshwater is increasing due to population growth and water scarcity. Traditional desalination systems are characterized by their high energy consumption, resulting in low efficiency and elevated costs. It is crucial to explore sustainable and eco-friendly desalination system to address these problems. Present study explores the impact of Al2O3 and ZnO nanofluids on a solar dish integrated water desalination system (SWDS). Performance evaluation includes energy, exergy, economic, exergoeconomic, and enviroeconomic perspectives. Compared to SWDS with water, annual freshwater productivity increased by 20.13% (Al2O3) and 12.56% (ZnO). SWDS with Al2O3 nanofluid exhibited the highest energy and exergy efficiency of 20.76% and 4.32%, respectively. Energetic parameters revealed a minimum energy payback time of 0.91 years and a maximum energy production factor of 27.18 for SWDS with Al2O3 nanofluid. The lowest cost per liter (CPL) was US$0.050 for Al2O3 nanofluids, while the highest CPL was US$0.0547 for ZnO nanofluid. The maximum exergoeconomic parameter was 2.50 kWh/US$ for SWDS with Al2O3 nanofluid. SWDS with Al2O3 nanofluid demonstrated the highest net CO2 mitigation of 72.54 tonne, with corresponding carbon credits of US$2124.08 (energy) and US$423.92 (exergy). The Al2O3 nanofluid-based SWDS demonstrated superior performance in energy and exergy perspective. Furthermore, Al2O3 nanofluid-based SWDS showed enhanced cost-effectiveness and environmental sustainability when compared to water-based SWDS.

Seasonal thermo-enviro-economic performance analyses of concentrated PV/T integrated with humidification-dehumidification water desalination system

Concentrated solar photovoltaic thermal offers a great opportunity for water desalination by applying some thermally driven techniques. Humidification–dehumidification water desalination is appropriate for moderate installations and runs on low temperatures matching the attainable output of low concentrated photovoltaic thermal systems. So, in this paper, thermo-enviro-economic performance analyses of an integrated system consisting of compound parabolic collectors partially covered with photovoltaic cells powering humidification dehumidification water desalination system is theoretically introduced. The system performance is conducted at a seasonal scale using MATLAB throughout the whole year under the weather of New Borg El-Arab city-Alexandria-Egypt. The results indicate that raising the flow rate of the working fluid of the system increases the desalination output, reduces the PV cell temperature, and enhances PV efficiency. At a fluid flow rate of 0.02 kg/s suitable for PV safety temperature, the cell maximum and minimum temperature are 79 and 42.5 °C, maximum and output power is 6 and 3.8 kW, and maximum and minimum efficiency is 17.2 and 14.2 % respectively. The output water temperature is 73 and 36.9 °C in summer and winter, respectively. The desalination system produces maximally 4.7, 6.2, and 3.8 L/h at water to air mass flow rate ratios of 1.5, 2, and 3, respectively. The maximum achieved average monthly desalination system gain output ratio is 3.15 with an overall system efficiency of 41 %. The average annual system thermal energy and exergy yield is approximately 176 and 0.2 kWh, respectively. The annual freshwater cost is $0.0351/Liter. The system mitigates an annual average of 7.2 tons of CO2 emissions.

Highly efficient 3D-screen printed interfacial solar water desalination system

Interfacial solar steam generation (ISSG) using floating devices is one of the most efficient and simple methods of purifying saline water. In this work, multi-layered solar steam generation systems are fabricated using 3D-screen printing. The printed devices with a uniform layer-by-layer structure contain light-harvesting, thermal insulation, thermal conduction, and water-transfer layers. The graphite (Gr) photothermal layer as an absorber layer is screen printed on the felt substrate with three different 3D patterns, which is isolated by transparent hydrophobic silica aerogel (SA) as a light scattering agent to provide efficient photon capturing and heat localization. Furthermore, to transfer the generated heat to the water proficiently, a copper (Cu) layer is coated on the downside of the absorber layer. The devices with the best performances are introduced by evaluating the effect of the fabricated layers thickness and different configurations. The multi-layered device containing a photothermal layer with SP1-3rd pattern and different thicknesses of SA 32 μm (under Cu), Cu 16 μm, Gr 32 μm, and SA 32 μm (on top of the Gr) shows a steam generation efficiency of 97 %, and water evaporation flux of 1.43 kg.m−2.h−1, which are 86 % higher than the performance of the reference system.

Energy, Exergy, Economic, and environmental assessment of a trigeneration system for combined power, cooling, and water desalination system driven by solar energy

Energy efficiency, exergy efficiency & destruction, economic, environmental, and error analysis analyses have been presented for the proposed trigeneration system. The metrics have provided an inclusive understanding of the proposed system's ability to effectively convert energy inputs to useful outputs while minimizing losses and waste. The goal is to optimize the cycle performance and find the most efficient configuration for meeting the Middle East's energy, cooling, and freshwater needs using a sustainable, solar-driven trigeneration system. The study has observed a system's increased energy and exergy efficiencies by 60.34 to 63.27 % and 25.98 to 29.59 % for the direct normal Irradiance (DNI) values varied from 600 W/m2 to 1000 W/m2. The total energy saving accounted by the proposed configuration is 4,453,220 USD/year as compared to the commercial electricity which includes the net energy production, energy saving through ejector and absorption cooling, and cost of water purification (through Reverse Osmosis Plant) in one year. The payback period of the plant mentioned in this is evaluated by 6.66 years. The CO2 mitigation is evaluated by 22,185.24 MT/year and the other pollutants can also be mitigated like SO2 by 40.425 MT/year and NOx by 136.415 MT/year.

MAISOTSENKO CYCLE FOR PROCESS WATER DISTILLATION AND DESALINATION

Search for new solutions for water distillation and desalination is one of the most important challenges facing scientists around the world. One of the promising methods of distillation and desalination of water is the use of the Maysotsenka cycle – a thermodynamic process, which use a psychrometric renewed energy available from the latent heat of water, which is evaporated into the airBy using the M-cycle, both energy savings and environmental benefits can be achieved. In this work, the technologies and technical solutions for distillation and water desalination systems according to the Maysovaluation cycle described in the literature are analized. Provided with diagrams of processes, installation and psychrometric diagrams. According to literature data, energy-saving distillation/desalination of water from stagnation of the M-cycle becomes 0.2…0.4 kW∙year/kg of water, which can compete with other desalination methods. The M-cycle has been shown to have the potential for a wide range of practical installations, while being characterized by a simpler installation design

Optimal design and economic analysis of a stand-alone integrated solar hydrogen water desalination system case study agriculture farm in Kairouan Tunisia

In the contemporary global discourse on environmental and developmental issues, the dual challenges of sustainable green energy and water supply stand paramount. These elements are vitally intertwined with the socio-economic vitality of the world. Notably, regions plagued by freshwater scarcity are increasingly turning to desalination which consists of a reliable and unconventional water source. The intersection of renewable energy with desalination and water purification processes presents a compelling synergy. This approach is particularly pertinent in areas where freshwater shortages coexist with abundant solar energy availability. Additionally, these technologies boast the advantage of low operational and maintenance costs. This paper delves into the design, optimization and financial analysis of a novel, standalone hybrid energy system, integrating photovoltaic and fuel cell technologies, for an agriculture farm situated in Kairouan, Tunisia. Unlike conventional systems, this model foregoes battery storage in favour of hydrogen storage, generated through water electrolysis powered by solar energy. This system harnesses solar energy for direct electrical power generation and hydrogen gas production. A segment of the generated electricity is allocated to electrolysis for green hydrogen production. In times of solar unavailability, the stored hydrogen is reconverted to electricity via a fuel cell. An intriguing aspect of this system is the utilization of saline well water, which, due to its high salt content, necessitates purification through desalination to prevent damage to the electrolysis unit and to render it suitable for agricultural irrigation.

Water desalination system via ion immobilization on iron corrosion-based colloids and filtration by kevlar support

An efficient, scalable water desalination line has been introduced based on ion immobilization on the corrosion-based colloids (Diameter: from 10 nm to 20 µm) and filtration by a kevlar support. These particles are generated based on the galvanic cell behavior of some semi-galvanized wiring bundles inside a water medium according to the electrochemical cell schematic: Fe|Fe2+, OH-, H2|H2O with ΔG° of −73.0 KJ mol−1. To have an efficient desalination process, the contributions of different mechanisms such as mixed salt crystals, co-precipitation, and /or formation of various ionic charged species are present. These interactions resulted in the formation of micro/nano colloids (suspensions) with Fe2+ with other cations and anions, randomly, inside the bulk water medium. These particles are sandwiched among the arrays of the kevlar slices (5.0 × 5.0 cm) and play the role of the filter medium. In the introduced water desalination process, the population of the iron-based suspensions is controlled via a descending setting of the mass percentage of the semi-galvanic iron bundling wires along the water desalination line to control the number (population) of iron-based particles. This phenomenon consequently approves the condition for the efficient water desalination process at a laminar mass transfer condition with Reynolds number < 2000. The important factors of the removal efficiency are optimized using a multivariate optimization method based on a controllable waste purification efficiency threshold. This system possesses adequate advantages such as high water desalination efficiency, an acceptable water purification rate (3.0 L h−1, for only one water desalination line), low cost, enough simplicity, no residual water, and no need for any external driving source(s).