Multi-effect Distillation Plant Research Articles

Review and Modeling of Integrated Energy Systems with Nuclear Reactor Coupled Desalination and District Heating

Detailed reviews of a past advanced nuclear reactor–based integrated energy system, as well as other nuclear reactor and fossil fuel–based integrated energy systems, have been performed for this work. A review of the utilization of heat from nuclear reactors for various applications and cogeneration has been done. The heat can be utilized by extracting the steam from the turbine while the steam is still at a desired temperature. While the use of nuclear process heat for district heating in countries like Finland, France, China, Poland, and elsewhere is discussed, more focus of the review has been given to nuclear desalination processes. Integrated energy systems (IESs), where distinct types of reactors like pressurized water reactors, boiling water reactors, sodium-cooled fast reactors, heavy water reactors, and other advanced reactors are coupled with various nuclear desalination processes, like multi-effect distillation (MED), multistage flashing, and reverse osmosis methods, are discussed. The nuclear desalination plant at Aktau is discussed in more detail due to its decades of successful operation. The IES of the Aktau plant coupled with a five-effect MED desalination plant was taken as a reference for modeling the Open Modelica (OM)–based IES in this work. The OM IES model shows good agreement with the MED plant output of Aktau and can be extended for future applications of IESs.

Comprehensive corrosion failure analysis of HAl77-2 alloy tubes serving in a low temperature multi-effect distillation plant: From feature analysis to corrosion mechanisms

Premature perforation and leakage of HAl77-2 alloy heat exchanger tubes occurs after 2.5 years of service in the largest low temperature multi-effect distillation (LT-MED) plant in China. The root reasons of perforation and leakage of tubes were investigated through macroscopic morphology, chemical composition, metallographic structure, seawater quality, flowing simulation and microstructure characterization. The results show that the HAl77-2 alloy tubes with perforation leakage meet the standard requirements. And the failure of the tubes was mainly attributed to the synergistic effect of serious pitting corrosion and stress cracking caused by the high fluid pressure and polluted seawater with Fe2+/Fe3+, sulfide and NH4+. Especially, the velocity and pressure spatial distribution of liquid film on the outside of horizontal tubes well verified the interesting observation that corrosion pits concentrating in one strip on the top of the tube. Moreover, corrosion mechanism was proposed that the loose corrosion products of Cu2S, FeS and Cu2(OH)3Cl lead to the formation of some defect points on the homogeneous protective Cu2O layer. For these defect points, the direct expose of the alloy matrix to corrosive substances such as Cl− and NH4+, significantly accelerates the dissolution of Cu in form of CuCl2− and Cu(NH3)2+ from the alloy. Finally, the tube occurs pitting corrosion and even perforates under the strong hydraulic erosion after long-terms of operation.

Computational fluid dynamics analysis of scaled Thermo-Compressor Performance in Multi-effect Distillation plants with Thermal Vapor Compression

This paper investigates scaled Thermo-Compressors for Multi-Effect Distillation with Thermal Vapor Compression (MED-TVC) desalination plants using Computational Fluid Dynamics (CFD). Initial validation compared CFD predictions with a real MED-TVC plant. Scaled-down Thermo-Compressors exhibited constant entrainment and pressure ratios, validating design scalability. The study expanded to test with compressed air as a practical substitute for steam under identical conditions. Results showed minimal deviation in entrainment and pressure ratios, affirming the feasibility of air testing. To account for temperature differences, a correction factor was introduced for accurate prediction when testing with air. Crucially, we explored substituting high-temperature steam with compressed air for testing. Lowering the air temperature allowed a reduced pressure of 13.12 bar while maintaining equivalent performance ratios compared to steam at 16 bar and 474.7 K. These findings are pivotal for developing small-scale Thermo-Compressor prototypes, facilitating testing with steam or air, and reducing risks and costs associated with full-scale fabrication. The study contributes practical insights for optimizing Thermo-Compressor designs in MED-TVC desalination, presenting compressed air as a viable alternative for efficient and cost-effective testing.

Non-target screening and prioritization of organic contaminants in seawater desalination and their ecological risk assessment

The impact of desalination brine on the marine environment is a global concern. Regarding this, salinity is generally accepted as the major environmental factor in desalination concentrate. However, recent studies have shown that the influence of organic contaminants in brine cannot be ignored. Therefore, a non-targeted screening method based on comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC × GC-qMS) was developed for identifying organic contaminants in the desalination brine. A total of 404 compounds were tentatively identified from four seawater desalination plants (three reverse osmosis plants and one multiple effect distillation plant) in China. The identified compounds were prioritized based on their persistence, bioaccumulation, ecotoxicity, usage, and detection frequency. Twenty-one (21) compounds (seven phthalates, ten pesticides, four trihalomethanes) were then selected for further quantitative analysis and ecological risk assessment, including compounds from the priority list along with substances from the same chemical classes. Ecologically risky substances in brine include diisobutylphthalate and bis(2-Ethylhexyl) phthalate, atrazine and acetochlor, and bromoform. Most of the contaminants come from raw seawater, and no high risk contaminants introduced by the desalination process have been found except for disinfection by-products. In brine discharge management, people believed that all pollution in raw seawater was concentrated by desalination process. This study shows that not all pollutants are concentrated during the desalination process. In this study, the total concentration of pesticide in the brine increased by 58.42%. The concentration of ∑PAEs decreased by 13.65% in reverse osmosis desalination plants and increased by 10.96% in the multi-effect distillation plant. The concentration of trihalomethane increased significantly in the desalination concentrate. The change in the concentration of pollutants in the desalination concentrate was related to the pretreatment method and the chemical characteristics of the contaminants. The method and results given in this study hinted a new idea to identify and control the environmental impact factors of brine.

Solar parallel feed multi effect distillation plant: An experimental study

This paper discusses about the parametric studies carried out on 10 m3/day capacity multi effect distillation desalination plant. In the present work studies were performed to determine the effect of process parameters on the production capacity of the MED plant. GOR of plant is around 3.6. Effect of solar irradiation on the evaporation rate in each effect is determined and presented with respect to time. Influence of the operating pressure and temperature on the performance of each effect is measured during the experiment and presented in the current work. Influence of steam input on the system performance is discussed. It was observed that increase in solar irradiation influences the steam production. Increase in the steam production rate influences GOR. Increase in the solar irradiation by 24% maximum on a typical day resulted in increase of evaporation rate by 20.6%, 17.3%, 15.7% and 12.3% corresponding to the effect 1, 2, 3 and 4 respectively. It was also observed that the production rate is found to be higher after the mid noon compared to the forenoon even though the solar irradiation is measured to be comparatively higher in forenoon than after mid noon.

Cogeneration of Fresh Water and Electricity with High-Temperature Power Cycles: Comparative Assessment of Multi-Effect Distillation and Reverse Osmosis

The pressing problems of water scarcity in many parts of the planet make water desalination one of the technological solutions for guaranteeing the fresh water supply. However, desalination processes require high energy consumption, mainly provided by fossil fuels. The integration of renewable energy sources into desalination processes is a promising option for decarbonizing the desalination sector. As most water-scarce regions with access to seawater frequently have high solar irradiation levels, it seems appropriate to exploit the sun to power the desalination process. This work presents the assessment of two integrated solar power and desalination systems regarding efficiency and water production. Two desalination processes (multi-effect distillation and reverse osmosis) are studied for potential coupling with the combined cycle of a central receiver solar plant to produce electricity and freshwater. In the case of the multi-effect distillation plant, it is integrated by replacing the Rankine cycle condenser of the combined cycle. In the case of the reverse osmosis plant, it is powered by the electricity generated from the combined cycle. For this comparison, the 21st of March has been considered as the design point and Almería (in the Southeast of Spain) as the plant location. The results show that the thermal cogeneration option renders a worse outcome (thermal efficiency of 50.2% for LT-MED case) than the decoupled generation of electricity and water (thermal efficiency of 53.3% for RO case), producing 18% less fresh water than the RO configuration (3831 m3/d vs. 4640 m3/d), due to the 6% penalty in the efficiency of the Rankine power cycle in the MED configuration as a result of increasing the condensation temperature from 42.6 °C to 70 °C.

Dynamic Modeling and Simulation of the Forward Feed MED-TVC Desalination Plant

The sudden disturbances in the operating parameters of desalination plants are common, especially when these plants are integrated with concentrated solar power (CSP). These disturbances damage the plants over time and may lead to a complete shutdown. This paper aims to investigate the performance of a forward feed multi-effect distillation plant with a thermal vapor compressor (FF-MED-TVC) which has a high potential for integration with concentrated solar power (CSP). However, the fluctuation and instability of solar energy require the development of dynamic model for the MED process to analyze the transient behavior. Few papers were published in the transient state, especially the forward feed (FF) configuration, as most of the papers focused on the parallel feed (PF) and parallel cross feed (PCF) configuration. Accordingly, a mathematical model has been developed using Engineering Equation Solver (EES) software and validated against data reported from two previous models in the literature, where a perfect agreement was obtained. Then the proposed model was employed to predict the system's response to the most important parameters that may change suddenly in the real operating environment, such as the variation in the motive steam pressure, feed seawater mass flow rate, and temperature. For the same percentage (10%) of these three disturbances, the results indicated that the needed time to return to 95 % of steady state is the longest in the case of increasing the seawater mass flow rate (about 350 seconds after the turbulence is removed), while it is the shortest in the case of increasing the pressure of motive steam (about 50 seconds after the turbulence is removed). In this paper, a comprehensive analysis of the transient performance was performed and a clearer view of the dynamic response was given which enables to optimize the control strategy and improve the stability.

Assessing the synergy between a seawater pumping system for mining facilities and the cooling system of a CSP plant in Northern Chile

The Atacama Desert presents the highest Direct Normal Irradiance (DNI) levels on the planet and at the same time is one of its driest places on Earth. The region concentrates a large number of copper mining facilities and is currently considered as a hotspot for the deployment of solar technologies. The mining activity consumes large amounts of water in its processes, and for driving such processes several of the facilities consider seawater pumping systems. The present article describes a technical and economic evaluation of coupling the cooling system of a Concentrating Solar Power (CSP) plant and the seawater pipeline. The analysis considers a location in northern Chile and the operation of a CSP plant, which is assessed using a validated simulation tool. The base scenario considers evaporative cooling, which is compared to other cooling approaches such as: dry cooling, once through, and coupling a Multi Effect Distillation (MED) plant, where the last two consider a connection to the pumping pipeline. The energy production and the resulting economic benefit are evaluated for each cooling scenario. It is observed that the scenarios using seawater deliver more energy than the dry cooling scenario. The once-through and MED cases show the best economic performance in terms of the Net Present Value (NPV). The simulations carried out allowed to identify the synergistic performance between the mining pumping system and the operation of the CSP plant, enabling to exploit additional benefits from its integration.

Thermodynamic assessment of a novel multigenerational power system for liquid hydrogen production

A Brayton plant-based multigenerational system is proposed and investigated thermodynamically through energetic and exergetic approaches in this study. Liquid hydrogen, electrical energy, heating-cooling and fresh water are the useful outputs produced by the combined plant. For this purpose, the Brayton cycle, organic Rankine cycle, multi-effect distillation plant, single-effect absorption cooling plant, hydrogen generation and liquefaction unit are used in the multigeneration system design. The study targets are to design a novel multigeneration system design, develop the related software codes, analyze the system thermodynamically, and evaluate the effects of plant design indicators. Thermodynamic assessment results indicate that the energy efficiency of the multigeneration system ranges between 63.64% and 74.31%, the exergy efficiency value ranges from 55.67% to 67.35%. Parametric analyses performed in this study indicate that the most influential parameter is the fuel mass flow rate. Also, it should be stated that an increase in the dead state temperature, combustion chamber temperature, and fuel mass flow rate positively affects the plant effectiveness.

Desalination plant integrated with solar thermal energy: A case study for the Brazilian semi-arid

The present work proposes a stand-alone process for brackish water thermal desalination for the Brazilian semi-arid (BSA) region. The Multi-Effect Distillation (MED) is coupled with solar collectors, a thermal energy storage (TES) system, a biodigester for electricity generation and a brine reject valorization scheme. The TES provides the continuous production of freshwater using solar energy alone, unlike other studies in the literature. The brine recycling affords lower amounts of brine reject than that reported in the literature for MED plants. A detailed cash-flow analysis estimates the economic feasibility of the plant and a water sales price of US$ 4.95/m³ for a plant with a capacity of 72 m3/day. The results indicate that thermal desalination is a cost-effective and sustainable alternative to mitigate the water shortage in the BSA region.

Techno-economic assessment of a hybrid RO-MED desalination plant integrated with a solar CHP system

In this study, an existing thermal multi-effect distillation (MED) plant was assumed to be integrated with reverse osmosis (RO) desalination system in a way that both heat and electricity demands of the hybrid RO-MED plant could be provided by a solar combined heat and power (CHP) system composed of parabolic trough concentrators (PTCs). For this purpose, the climatic conditions of Bushehr province (latitude 28.7621° N; longitude 51.5150° E), located in the south of Iran, was considered as the case study, and the water demand of 1,000 m3/day was assumed. In the first step, new algorithms were developed to integrate RO and MED desalination plants, and an incorporated thermal energy storage (TES) system was designed using the MATLAB program. Additionally, the whole system including the RO-MED plant and the solar CHP system was mathematically modeled and their performance was technically and economically evaluated. To perform this, four scenarios including recovery values for RO and MED as 50% and 30% (scenario 1), 50% and 35% (scenario 2), 55% and 30% (scenario 3), and 55% and 35% (scenario 4) were deemed. The results revealed that, first of all, the fourth scenario yields the highest total recovery amounts in all considered shares of freshwater production between two desalination plants. Secondly, under this scenario, the optimum total recovery can be obtained when each desalination plant produces 50% of the required freshwater, leading to a 15% rise in total recovery in hybrid mode, compared to the use of a single MED unit. Moreover, it was found that the integration of the TES unit can extend the working hours of the system by 30% under daylight irradiation. From calculations, the number of required PTCs in the solar field was calculated as 188 with a total aperture area of 17,869 m2. The economic evaluation of the designed system illustrated that the integration of a RO plant with an existing MED system could reduce the total cost of the produced freshwater for 6700 people from 2.08 US$/m3 for a single solar-powered MED plant to 1.918 US$/m3 for the solar-powered RO-MED plant.

Multi-objective optimization of a Concentrating Solar Power + Photovoltaic + Multi-Effect Distillation plant: Understanding the impact of the solar irradiation and the plant location

• The impact of the location parameters in a CSP + PV + MED is analyzed. • Multi-objective optimization is performed to minimize thermoeconomic costs. • The irradiation and distance have the most significant impact on the costs. • Cost maps of the thermoeconomic cost of electricity and water are presented. This research work presents the assessment of the impact of the solar irradiation, the distance from the coast, and the altitude of the location for a Concentrated Solar Power + Photovoltaic + Multi-Effect Distillation (CSP + PV + MED) plant for simultaneous power generation and seawater desalination. For that, a comparative analysis of the thermoeconomic cost of electricity and water (TCE and TCW) at different locations is carried out to determine the most competitive sites where this kind of cogeneration plant can be deployed. Also, multi-objective optimization is performed to assess the optimum sizing that allows reducing the costs. The study considers four Direct Normal Irradiation (DNI) levels (from 2000 to 3500 kWh/m 2 -yr), six distances from the sea (from 5 to 100 km), and six altitudes (from 20 to 1000 m.a.s.l.). The results show that solar irradiation has the most significant effect on the TCE and TCW, the distance to the sea affects the TCW considerably, and the altitude has a moderate impact despite its impact is substantially lower than the other two factors. Also, cost maps of the TCE and TCW giving insights about which locations have a higher potential for developing CSP + PV + MED plants are presented. From these maps, it has been found that the potential inland locations to reach TCE and TCW under 100 $/MWh and TCW 2 $/m 3 should have high DNI (at least 300 kWh/m 2 -yr above the coast level), distances from the coast up to 60 km, and altitudes up to 750–1000 m.

Sustainability Assessment and Techno-Economic Analysis of Thermally Enhanced Polymer Tube for Multi-Effect Distillation (MED) Technology.

Metal-alloys tubes are used in the falling-film evaporator of the multi-effect distillation (MED) that is the dominant and efficient thermal seawater desalination process. However, the harsh seawater environment (high salinity and high temperature) causes scale precipitation and corrosion of MED evaporators’ metal tubes, presenting a serious technical challenge to the process. Therefore, the metal/metal alloys used as the material of the MED evaporators’ tubes are expensive and require high energy and costly tube fabrication process. On the other hand, polymers are low-cost, easy to fabricate into tubes, and highly corrosion-resistant, but have low thermal conductivity. Nevertheless, thermally conductive fillers can enhance the thermal conductivity of polymers. In this article, we carried out a feasibility-study-based techno-economic and socioeconomic analysis, as well as a life-cycle assessment (LCA), of a conventional MED desalination plant that uses titanium tubes and a plant that used thermally enhanced polymer composites (i.e., polyethylene (PE)-expanded graphite (EG) composite) as the tubes’ material. Two different polymer composites containing 30% and 40% filler (expanded graphite/graphene) are considered. Our results indicate that the MED plant based on polymer composite tubes has favored economic and carbon emission metrics with the potential to reduce the cost of the MED evaporator (shell and tubes) by 40% below the cost of the titanium evaporator. Moreover, the equivalent carbon emissions associated with the composite polymer tubes’ evaporator is 35% lower than titanium tubes. On the other hand, the ozone depletion, acidification, and fossil fuel depletion for the polymer composite tubes are comparable with that of the titanium tubes. The recycling of thermally enhanced polymers is not considered in this LCA analysis; however, after the end of life, reusing the polymer material into other products would lower the overall environmental impacts. Moreover, the polymer composite tubes can be produced locally, which will not only reduce the environmental impacts due to transportation but also create jobs for local manufacturing.

Concentrating solar power multi-effect desalination in Al Khobar, Saudi Arabia

As about two-thirds of the thermal energy to the power cycle of a concentrated solar power plant is dumped to the condenser, typically air or evaporative cooling, there is the opportunity to achieve energy savings by using a multi-effect distillation system to condensate the steam and at the same time produce desalinized water. Preliminary design considerations and computations for a concentrated solar power plant located in Al Khobar, Saudi Arabia, are here proposed. The solar field has an aperture of 1,230,000 m2, it uses oil as the receiver fluid, it uses a six hours’ thermal energy storage by molten salt, and it features a 140 MW turbine. It is expected production of up to 413 GWh of electricity annually, for a capacity factor of 0.36, by using an air-cooled condenser. Adoption of a glass enclosure and a multi-effect distillation plant replacing the air-cooled condenser may permit the same electricity production plus the production of desalinized water in an environment protected by sand and dust.

Multi-objective optimization of hybrid nuclear power plant coupled with multiple effect distillation using gravitational search algorithm based on artificial neural network

In this study, multi-objective optimization has been performed for finding the best net electric efficiency, gain output ratio, and fresh water cost in a nuclear co-generation plant. Bushehr nuclear power plant (BNPP) with 1000 MWe nominal power with a MED (multi-effect distillation) desalination system is selected. The BNPP is simulated with Thermoflow software and energy analysis of flow cycle has been carried out. The MED plant with a capacity of 25,000 cubic meters per day is coupled. The desalt water cost was evaluated by DEEP software and the gravitational search algorithm (GSA) has been performed to optimize the co-generation plant. The performance of the gravitational search algorithm has been proven by the Griewank test function compared to the harmony search and particle swarm algorithms. An artificial neural network with 10 thermodynamic inputs related to the power plant, intermediate loop, and desalination system has been used to predict fitness function for the optimization process. The network is created with Levenberg-Marquardt back-propagation algorithm with a 0.27% probable error. Energy analysis showed that the power plant's efficiency before coupling the desalination system is 33.93%. The multi-objective optimization results demonstrated that 0.1123 is the best fitness function found by the algorithm, according to which the minimum cost of desalted water is 1.07 $/m3, gain output ratio is 13, and net electric efficiency is 33.3%.

Annual thermoeconomic analysis of a Concentrating Solar Power + Photovoltaic + Multi-Effect Distillation plant in northern Chile

A detailed annual performance and thermoeconomic analysis of a Concentrated Solar Power plant coupled to a Photovoltaic and a Multi-Effect Distillation plants (CSP + PV + MED) were performed using an extensive methodology based on an hourly simulation. The aim was to assess the impact of the PV integration into the CSP + PV plant and to evaluate the sizing of the plant in terms of the design parameters (PV plant size, solar multiple, Thermal Energy Storage capacity, and numbers of MED units) that allow achieving the lowest thermoeconomic electric and water costs (TCE and TCW). Results show that PV integration mainly increases the electric output but could increase the water production depending on the PV and CSP plants’ sizes. Moreover, the PV plant cost is mainly allocated to electricity, decreasing the TCE, while on the TCW it has a moderate impact. Finally, it was found that the PV plant and the CSP plant size has contradictory roles between the costs, where the minimum TCE is obtained for large PV plant with an undersized CSP plant and one MED unit, and the minimum TCW is obtained for small PV plant with an oversized CSP plant and a large MED plant (5 units).

Technical assessment of LNG based polygeneration systems for non-interconnected island cases using SOFC

Liquefied Natural Gas (LNG) is one of the most promising fuels with high calorific value and low specific GHG emissions that offers several advantages as an energy carrier for power generation. In this paper, a novel polygeneration concept based on LNG fired plant for power, cooling and drinking water production in island systems is presented. Two Solid Oxide Fuel Cell based energy systems (one simple SOFC and another hybrid concept of SOFC combined with GT) are modelled in Aspen Plus and compared with two conventional combustion based technologies (internal combustion engine and Gas Turbine Combined Cycle) in terms of overall efficiency. Furthermore, a Low Temperature Multi-Effect Distillation (LT-MED) plant was modelled and coupled with the energy systems to evaluate the waste heat recovery potential for desalinated water production. Moreover, three concepts for cold recovery from the LNG regasification plant were presented and modelled. Process simulations results revealed that the hybrid SOFC-GT plant is the best solution in terms of energy efficiency and the heat recovery of the exhaust gas in a LT-MED unit is a promising option for drinking water production with almost no energy cost. Last, from exergetic point of view, the cryogenic energy storage (CES) via the production of liquid air was evaluated as the best option for waste cold utilization during LNG regasification.

Thermal desalination potential with parabolic trough collectors and geothermal energy in the Spanish southeast

Desalination industry has become essential for the survival of the population in places with shortages of fresh water. Because is a costly process, the constant search for the best local renewable energy sources is a necessity.A theoretical Multi-effect distillation plant of 9000 m3/d located in the southeast Spanish (Almería) is intended to fed thermally with solar (parabolic trough collectors) and geothermal energy.Starting from the history of solar irradiation and temperatures of the province of Almería from 1994 to 2016 provided by Solargis database, a discrimination of the profile of temperatures is obtained at the exit of the solar panels. Putting in common the profile exit temperatures and the potentiality of the geothermal resource at the depth in the area under study, a series of possible configurations are obtained.The theoretical results of the study indicate that during 76% of the annual time is achieved with both resources (solar and geothermal) at that depth of the well in that specific climatological zone (490 m, t = 41.8 °C).Since the thermal gradient in the area is 8.87 °C per 100 m depth according to the studies carried out, only geothermal energy would be necessary at deep of 790 m to obtain working temperatures of the desalination plant at 70 °C.Applying the results to the existing desalination plants of the Spanish project named Actions for the Management and Utilization of Water is obtained 6 years of amortization and 510,387,920 kg/y CO2 avoided to the atmosphere for all of these plants.

Multi-effect distillation plants for small-scale seawater desalination: thermodynamic and economic improvement

The growing global demand for fresh water coupled to the increasing interest in renewable energies and waste heat recovery has resulted in flourishing attention to the multi-effect distillation process for seawater desalination. The low operating temperature makes this technology attractive in the case of low temperature heat sources such as geothermal, solar or waste heat recovery. The low energy density of these heat sources requires small-scale desalination systems whose layout and operation may differ from large-scale plant. In this work, new plant configurations for a small-scale multi-effect distillation system are proposed and analyzed from a thermodynamic and economic point of view. Each configuration tends to better exploit the energy content of the various streams by improving heat recovery, according to an increasing layout complexity. These configurations were studied in two layouts, differing in the way seawater and brine fed the various effect. The feed mass flow in each effect was varied to maximize the recovery ratio by imposing the maximum salt concentration in the brine related to calcium sulphate precipitation. Numerical simulations were conducted in Aspen Plus environment by varying the top brine temperature with a fixed bottom brine temperature of 40 °C. The electrolyte non-random two liquid equation of state was adopted to evaluate saltwater properties and an inter-model comparison with a validated algebraic model was carried out. The configurations implementing seawater preheating increased the performance ratio up to 10% due to the better exploitation of the energy content of distillate streams. The proposed solutions with the maximization of the recovery ratio demonstrated to be cost-effective with respect to the base multi-effect distillation configuration when thermal energy cost became relevant. In the case of negligible thermal energy cost (waste heat recovery) the base configuration was the preferable solution in terms of water cost, despite the lower performance ratio.

Design and economic evaluation of solar-powered hybrid multi effect and reverse osmosis system for seawater desalination

Reducing the cost of fresh water has always been a major concern in the desalination industry. A solar powered hybrid multi-effect distillation and reverse osmosis desalination plant (MED + RO) has been designed and optimised from an economical point of view in a previous work by the same authors. In the present study, the possibility of coupling the desalination plant with a photovoltaic (PV) solar farm is investigated, with the aim of generating electricity at low cost and in a sustainable way. A detailed mathematical model for the PV system has been implemented from the literature. Interestingly, the model can predict the cost of the PV system in terms of capital cost and electricity cost per kWh considering the input data of solar irradiation, duration of daylight and technical specification of a real solar module. Consequently, the solar PV model has been combined with the desalination model, which enables to estimate the cost of fresh water per cubic meter. Data about four locations, namely Isola di Pantelleria (IT), Las Palmas (ES), Abu Dhabi (UAE), and Perth (AUS), have been used to economically test the feasibility of installing the proposed plant, and especially of the PV solar farm.