Water Desalination System Research Articles

An optical concentrator coupled multistage solar steam generation system for solar thermal-latent heat cascade utilization and water desalination: Performance and economic benefit analysis

Solar steam generation (SSG) for water treatment has attracted great interest for its convenience, accessibility and eco-friendliness. However, water production rate of traditional floating structure SSG system is relatively low. To further increase the water production rate, we develop a solar thermal-latent heat cascade utilization SSG system coupled with compound parabolic concentrator for desalination. A 2 × compound parabolic concentrator (CPC) was used in the outdoor experiment to improve the incident solar flux. Solar absorber of the SSG module has a high solar absorbance of 95 % which can effectively harvest solar energy and convert it into heat. A thin air gap above the solar absorber can restrain thermal loss through convection and radiation. Within the SSG module, seawater was supplied for the evaporation process driven by the capillary force in the capillary wick. Through the multi-stage design, solar thermal conversion and latent heat cascade recovery were achieved. As a result, the SSG module can achieve a gain to output ratio (GOR) of 185.09 % with a water flux of 2.82 kg∙m−2∙h−1 under one sun. Concentrating solar flux reached 1300 W∙m−2 in an early autumn day and a corresponding water flux of 3.5 kg∙m−2∙h−1 was achieved. Theoretical analysis showed that higher solar flux can increase the GOR. Optical concentration of 2 × can increase annual fresh water by 1.72 times while maintaining economic benefit. An insulation air gap above the solar absorber can reduce thermal loss from the solar absorber. Increasing stages can increase number of times the latent heat being reused and improve GOR, but economic benefit decreased with the increase of stage number. Considering the economic benefit and floor area, optical stage number of the system should be 4. Annual water production evaluation showed that a 1 m2 area system can annually generate 6321.29 kg fresh water with a water production cost of 7.03$/m3.

A review on evaporation improvement of solar still desalination using porous material

Recently, many studies have focused on desalination systems using solar energy sources due to low energy costs, the feasibility of usage in most weathers and no use of fossil fuels. Different materials have been proposed to enhance the temperature gradient and to gain better water productivity of the system such as porous materials, nanoparticles and phase change materials. Due to the uneven and porous surface, the porous materials raise the solar intensity absorption and the water temperature. This present review article assists to study the implementation of porous materials in evaporation enhancement of solar water desalination systems. All previous studies have demonstrated that the use of porous materials has a significant influence on the evaporation rate in solar desalination systems. Eventually, a summary of comparison in previous publications was presented and discussed in detail to assist researchers and engineers with a better design of solar still desalination systems. The achieved outcomes indicated that the energy efficiency of the solar desalination using activated carbon as a porous media was enhanced by 94.14%. Moreover, the productivity of the solar still desalination by aluminium fins and black steel wool fiber as a porous material was increased by about 42.3% and 20.9%, respectively.

Experimental investigation of membrane distillation with bubble column dehumidifier system for water desalination

The performance of a new integrated system of single-stage sweeping gas membrane distillation module and a bubble column dehumidifier (SGMD-BCD) was experimentally investigated. The productivity and energy consumption of the system is evaluated under different operating conditions. The SGMD module acts as a humidifier to produce high-quality distilled and the bubble column dehumidifier is an effective condenser for improved performance. The sweeping air stream is created in two different ways; using a vacuum pump and compressed air. Results showed that the integrated system yields higher permeate flux, better gained output ratio (GOR), and lower specific thermal energy consumption (SEC) when the vacuum pump is used. Increasing the feed temperature from 50 to 80 °C increased the flux by 175%, on average. Doubling the sweeping air flow rate from 1 to 2 SCFM resulted in flux enhancement of 49% and 25% for the vacuum pump and the compressed air supply, respectively. Operating the system with the vacuum pump and without cooling the bubble column dehumidifier showed a marginal reduction in flux but resulted in significant improvements in GOR and SEC values of 0.76 and 909 kWh/m3, respectively, at an optimum dehumidifier water column height of 9.5 cm.

Triple-renewable energy system for electricity production and water desalination

This work presents a novel triple-renewable energy system (TRES) that is based on integrating the photovoltaic panels (PVPs), conventional solar chimney (CSC), and cooling tower (CT) in one structure. The ultimate objective of the proposed TRES system is to produce electrical power (Pelc), desalinated water (Dw), and if required cooling utilities. The components of the system include a chimney tower, collector, base, PVPs, water pool, bi-directional turbine, and water sprinklers. The TRES system can be operated as CSC during the daytime and CT at night providing 24-h operation. The PVPs were integrated within the structure to increase the Pelc production and enhance the process performance by heating the air inside the system. The TRES structure increased the efficiency to 0.860% in comparison with the CSC (0.313%). The annual Pelc production from the TRES system was found to be 792 MWh compared with only 380 MWh generated by the CSC achieving 2.1 folds overall improvement. The CSC-PV and CT contributed to 47% (494 MWh) and 24% (253 MWh) of the Pelc production, respectively. The annual Dw production was found to be 1.2-fold higher (163,142 tons) higher than the CSC (139,443 tons). The newly developed TRES system offers a great potential to produce Pelc and Dw and save fossil fuel consumption while reducing the emissions of greenhouse gasses (GHGs) to the atmosphere.

Performance analysis of nanofluid-based water desalination system using integrated solar still, flat plate and parabolic trough collectors

Performance analysis of nanofluid-based water desalination system using integrated solar still, flat plate and parabolic trough collectors

Evaluating the Performance of a Solar Distillation Technology in the Desalination of Brackish Waters

Desalination is set to become a major source of drinking water in several Middle Eastern countries over the coming decades. Solar distillation is a simple power-independent method of water desalination, which can be carried out in active or passive modes. This study is among the first attempts to investigate the possibility of desalinating brackish groundwater resources under the threat of saltwater intrusion in the southern areas of Razavi Khorasan province in Iran. For this purpose, a pilot solar distillation unit was constructed to analyze the effects of the unit orientation, depth of the water pool, atmospheric conditions, input salinity, and flow continuity on the solar distillation performance. The results showed that the unit exhibited the highest efficiency when it had a 3 cm deep water pool. It was oriented facing southward while operating a continuous flow for at least 3 days under sunny weather conditions. It was found that among the studied parameters, the unit orientation and pool depth had the greatest impact on the water production performance for this type of water desalination system. Conversely, the water production efficiency was not very sensitive to the input salinity level. Overall, the solar distillation technology was able to reduce the salinity by 99.7% and the hardness by 94.7%.

Pembuatan Sistem Desalinasi Kapasitas 240 liter/jam di Dusun Bondan Kecamatan Kampung Laut Cilacap

Dusun Bondan is a district located in a tidal area. Various problems arise in Dusun Bondan because of the use of water that doesn’t meet the quality of sanitation water causing several diseases. The water crisis experienced by the residents of Dusun Bondan becomes the worst disaster especially in summer because the water at Dusun Bondan is salty with high total dissolved solids. A water desalination system has been made to produce sanitation water that meets the standard based on Minister of Health Regulation No. 32 of 2017. The methods used to overcome these problems are water source identification, design of desalination system, purchasing, fabrication and testing of desalinated water. The result of the activities is a desalination system which consists of pre-treatment using 4 filtration stages ended with reverse osmosis desalination using a special membrane. The result of desalinated water test shows that the water is odourless, tasteless, and other parameters meet the requirement of the standard.

Pembuatan Sistem Desalinasi Kapasitas 240 liter/jam di Dusun Bondan Kecamatan Kampung Laut Cilacap

Dusun Bondan is a district located in a tidal area. Various problems arise in Dusun Bondan because of the use of water that doesn’t meet the quality of sanitation water causing several diseases. The water crisis experienced by the residents of Dusun Bondan becomes the worst disaster especially in summer because the water at Dusun Bondan is salty with high total dissolved solids. A water desalination system has been made to produce sanitation water that meets the standard based on Minister of Health Regulation No. 32 of 2017. The methods used to overcome these problems are water source identification, design of desalination system, purchasing, fabrication and testing of desalinated water. The result of the activities is a desalination system which consists of pre-treatment using 4 filtration stages ended with reverse osmosis desalination using a special membrane. The result of desalinated water test shows that the water is odourless, tasteless, and other parameters meet the requirement of the standard.

Optimal design of multi-stage vacuum membrane distillation and integration with supercritical water desalination for improved zero liquid discharge desalination

This paper proposes a novel concept for the optimal design of multi-stage vacuum membrane distillation (VMD). Generally, a multi-stage VMD is designed with an equal temperature difference between each stage. However, such a design is energy inefficient and increases VMD area. An analytical methodology for calculating the optimal stage temperature is proposed. By selecting the optimal stage temperature, the energy efficiency and required membrane area can be potentially improved by 16% and 30%, respectively. The proposed concept applies to all heat sources, including latent, sensible, and waste heat. To illustrate the method, multi-stage VMD is integrated with the waste heat from a supercritical water desalination (SCWD) system to achieve zero liquid discharge. SCWD is an energy-intensive process, requires high-quality thermal heat (>450 °C), and exhibits high waste heat rejection. The integrated VMD-SCWD approach is approximately 50% more energy-efficient and 35% more cost-efficient than the standalone SCWD system. Compared to the commercially used brine concentrator and crystallizer, the multi-stage VMD-SCWD system is more energy efficient for feed concentrations >5%. VMD-SCWD system is 30% cheaper, due to less expensive membrane distillation modules compared to a brine concentrator. The proposed design concept can replace the brine concentrator and crystallizer as an improved alternative for a zero-liquid discharge desalination system.

Vacuum-Assisted Multistage Membrane Distillation With Bubble Column Dehumidifier for Efficient Water Production

Abstract An experimental investigation of a novel integrated system of a multistage sweeping gas (air) membrane distillation module and a bubble column dehumidifier (BCD) is presented for an energy-efficient high production water desalination system. The sweeping air stream is created using a vacuum pump installed between the membrane distillation unit and the BCD to apply a degree of vacuum behind the membrane in the air channel of the membrane cell to reduce the vapor mass transfer resistance through the membrane pores. Performance metrics of the system include the measurement of permeate flux and the calculations of energy consumption at various operating conditions in a comprehensive manner. The system performance is mainly controlled by feed temperature and flowrate and the sweeping air flowrate. The dehumidifier water level and its temperature have moderate impacts in the tested ranges. A permeate flux of 18 kg/m2 . h was measured with a relatively high gained output ratio of 0.62, low specific energy consumption of 1120 kWh/m3 when the feed temperature is 80 °C, and the dehumidifier column height of 4.5 cm. The study results revealed an enhanced system’s performance compared to other sweeping gas membrane distillation systems in the literature, which is very promising.

Solar powered adsorption desalination system employing CPO-27(Ni)

Adsorption-based desalination system (ADS) is an alternative technology to the traditional water desalination systems as low-temperature sources can operate it. Also, ADSs use environmentally friendly materials, limiting global warming and environmental pollution. This work investigates the performance parameters of ADS powered by an evacuated thermal solar collector theoretically and experimentally. The system uses an advanced sorption material of metal-organic frameworks called CPO-27(Ni). The study estimates optimal operating conditions of ADS under the climate of Egypt. A mathematical model is carried out using MATLAB integrated with TRNSYS software. The study investigates high system performance through two modes; without heat recovery (Mode-1) and heat recovery (Mode-2). The ADS performance is evaluated by specific daily water production (SDWP) and gain output ratio (GOR) parameters. The results show a remarkable superiority for mode-2 as it achieved 10 (m3/ton-day) SDWP and 0.4 GOR, while mode-1 achieved about 5 (m3/ton-day) SDWP and 0.23 GOR at the optimum operating conditions. The improvement ratio using mode-2 reached 88 % of SDWP and 79 % of GOR. Also, the validation results showed a good qualitative and quantitative agreement between the experimental and theoretical data.

Design Analysis of a Solar-Powered Water Desalination System Using Humidification Dehumidification for Continuous Water Production

This paper aims to introduce thermal energy storage technology into a solar-powered dual-packed bed desalination system. By prehesdating and reserving seawater during the daytime and utilizing it at night, the integrated desalination system with innovative configuration can achieve freshwater and electricity combined generation and particularly realize the continuous operations for water production. The detailed mathematical model is established, and the corresponding parametric analyses are executed with various operating situations. The simulation results show that with the rise of top temperature, the performance indicators of the system, gained-output-ratio (GOR), and water productivity, reach the maximum value at the MFRR corresponding to the balance condition of dehumidifier, while the power generation of photovoltaic/thermal (PV/T) reaches minimum value under different incident conditions. It is summarized that the balance condition also represents the upper limit of air compensation capability and the “turning point” of air temperature, which can be enhanced by raising the top temperature of the system. Furthermore, the integrated system outperforms other HDH configurations in prior research, demonstrating the feasibility and superiority of the present continuous water-producing HDH system supported by thermal energy storage.

Effect of membrane surface wetting on the performance of direct contact membrane distillation for seawater desalination

Membrane distillation (MD) is a standalone process to generate fresh water and is especially attractive when low-grade waste heat or renewable thermal energy is available. Surface wetting hinders the commercialization of Membrane distillation (MD) technology by deteriorating the permeate quality, thermal efficiency, and transmembrane flux. There is still a lack of understanding on how and to what extent the partially wetted membranes affect the performance of direct contact MD (DCMD) systems. It is of great importance to optimize the operating conditions under such conditions. The DCMD performance was addressed in the literature by considering non-wetted or fully wetted membranes. This study for the first time proposes a computational model to investigate the effect of membrane surface wetting ratio (R = L wet /L total ) on the transmembrane (J) and thermal efficiency (η) of a DCMD module. Parametric and sensitivity analyses were performed to display the effect of system parameters (feed temperature, feed velocity, permeate temperature, permeate velocity, membrane thickness, and membrane surface wetting ratio) on the Key Performance Indicators (KPIs) of the DCMD module. The obtained results indicate that the permeate side temperature has more effect (more than twice) on KPIs in wetted membranes (∼30% and ∼15% rise in J and η) compared to the non-wetted ones (∼15% and ∼5% enhancement in J and η), and the negative effect of membrane surface wetting could be minimized by adjusting the permeate side operational conditions. The effect of membrane wetting ratio on the performance of the DCMD module in thin membranes (≤0.2 mm) and thick membranes (≥0.25 mm) strongly depends on the permeate and feed temperatures. The parametric and sensitivity analysis performed in this study will be beneficial to optimizing the operational conditions of MD systems for maximizing their performance and could serve as valuable guidelines in the development of efficient water desalination systems. • A numerical model was developed to investigate the performance of the partially wetted DCMD module. • The effect of surface wetting ratio (R = L wet /L total ) was investigated using a parametric study. • A sensitivity analysis was performed to quantify the relative impact of operating conditions. • The effect of permeate properties is more dominant for surface wetted membranes. • Permeate and feed temperatures dramatically alter the R ratio effect in thin and thick membranes, respectively.

A novel combination of absorption heat transformer and refrigeration for cogenerating cooling and distilled water: Thermoeconomic optimization

A novel cogeneration system consisting of an absorption heat transformer and refrigeration system integrated with a water desalination system is proposed, analyzed, and optimized. The cogeneration and desalination systems interacted thermally. The proposed system is flexible in producing cooling and distilled water with variable fractions. Influences on system performance are investigated of the decision parameters. A maximum value of 39 °C is achieved for gross temperature lift. Also, it is observed that the condenser temperature, which is influenced by climate conditions, affects system performance. The system performance is optimized considering such criteria as exergy efficiency, the rate of distilled water production, and total product unit cost. Depending on the criteria used for optimization, the results indicate a minimum total product unit cost of 42.6$/GJ, a maximum exergy efficiency of 27.9%, and a maximum distilled water mass flow rate of 0.53 kg/s. The minimum total capital cost rate and exergy destruction cost rate are found to be 11 $/h and 3.89 $/h, respectively. Under optimized conditions, the generator is seen to contribute the most to the total exergy destruction rate. The values of levelized cost of energy and water and payback period are 0.013 $/kWh, 9 $/m3 and 1.8 year, respectively.

Tri‐objective optimization of a synergistic wind‐photovoltaic plant for water desalination addressing sustainable development goals

AbstractThe sixth goal of the Sustainable Development Goals (SDGs) announced by the United Nations addresses water and sanitation; its first target is providing safe and affordable drinking water. Water desalination is introduced as a viable alternative considering the present situation of the water resources and their consumption and pollution. However, desalination processes' high energy intensity conflicts with energy and climate‐related SDGs. Correspondingly, the first target of SGD 6 can be translated to an affordable, eco‐friendly, and reliable water desalination. However, these objectives are conflicting considering the current status of desalination. Accordingly, this article proposes a novel multi‐objective model by quantifying the interweaved sustainable development goals for water desalination. To this end, a tri‐objective mixed‐integer linear model is developed to compromise the abovementioned goals, that is, water production cost, supply reliability, and carbon emission. The proposed water desalination system is fed by a combined wind‐photovoltaic‐diesel system, employs power and water storage, and seeks a trade‐off solution based on the planner's preferences. The model is flexible in terms of the degree of achievement of each goal. A detailed analysis is performed, enabling the decision‐maker to comprehend the goals interlinkage based on the degree of achievements and deterioration concerning the other goals.

Advancements in solar technologies for sustainable development of agricultural sector in India: a comprehensive review on challenges and opportunities.

Agriculture is the main occupation of the majority of people in India. The majority of the population in India is dependent (directly or indirectly) on agriculture as an occupation. The agriculture sector requires more freshwater and power for better yield in the current scenario. Nevertheless, the ever-increasing rate of energy consumption, limited fossil fuels, and rising pollution have made the expansion of renewable resources essential. Due to the suitable solar potential available in India, the deployment of solar energy has been more as compared to other renewable resources. The current study aims to discuss the various technologies, initiatives and policies of solar energy usage in agriculture. This work delivers an assessment of the advancement of solar energy vis-à-vis agricultural applications through the greenhouse concept and photovoltaic approach in India. Various agricultural applications of solar energy, such as solar water desalination system, solar water pumping system, solar crop dryer system for food safety, etc. are discussed as a means to promote solar-based technology. It also highlights the scenario of solar energy in India with important accomplishments, developmental approaches, and future potential. In-depth studies of various policies and government initiatives including those in research and development are also discussed. The current survey on solar technologies will be an aid to agribusiness frameworks to comprehend the statuses, obstructions, and extent of advancement. Finally, some future recommendations for further developments in this approach are discussed. This work sheds light on varied areas of solar energy-assisted agricultural systems as a potentially sustainable and eco-friendly pathway.

A Biomass‐Based Hydrogel Evaporator Modified Through Dynamic Regulation of Water Molecules: Highly Efficient and Cost‐Effective

Solar‐driven hydrogel evaporator used for water purification demonstrates great potential in seawater desalination and domestic sewage treatment. However, much uncertainty still exists about the most efficient design to obtain cost‐effective drinkable water. In this paper, a natural rich biomass Nicandra physalodes (Linn.) Gaertn. polysaccharide was introduced into the polyvinyl alcohol network to control the water distribution during evaporation and build a low‐cost hybrid hydrogel solar evaporator with a total material cost of $7.95 m−2. The mixed evaporator works stably in a long‐span acid–base range (pH 1–14) and salinity range (0–320 g kg−1). Its daily water purification capacity can reach 24.4 kg m−2 with a water purification capacity of 3.51 kg m−2 h−1 under sunlight. This paper provides a new possibility for a highly efficient and cost‐effective water desalination system with guaranteed water quality by focusing on the dynamic regulation of water molecules at the evaporation interface.

Natural Porous Materials for Interfacial Solar Steam Generation toward Clean Water Production

The progression of photothermal materials with broad solar absorption and improved photothermal conversion efficiency is critical for developing interfacial solar steam generation (ISSG)‐based water desalination and purification systems. This green solar‐driven water vaporization technology has regained popularity as a sustainable solution to water shortage. Among many other photothermal materials, natural porous material‐based photothermal evaporators have piqued the interest of researchers owing to their biodegradability, abundance, low thermal conductivity, low cost, natural capillary mechanism, and hydrophilicity. In this review, recent advances in photothermal material design based on various natural porous materials are reported, systems considering contact mode and the water transportation route are categorized, optical absorbance is assessed, and thermal management issues and water purification as well as desalination applications are discussed. This review stimulates further investigation and research interest in the utilization of natural porous materials for large‐scale ISSG‐based application implementation.

Cavitation flow pulsation mechanism of axial high-pressure plunger pump in the sea water desalination system

Cavitation flow pulsation mechanism of axial high-pressure plunger pump in the sea water desalination system

Psychometric study and performance investigation of an efficient evaporative solar HDH water desalination system

The improvement of the evaporation process can significantly improve water production and the overall efficiency of a solar humidification-dehumidification (HDH) system. This study experimentally investigates the use of novel packing materials to improve the performance of the humidification process. Contact time and area between sprayed water and surrounding air are two critical parameters that considerably influence evaporation. Therefore, using selected packing materials inside the humidifier can increase these two parameters. A wet cooling tower facility is used as a humidifier with instrumentations installed to measure the inlet and outlet air and water conditions. Among different materials tested, it is found that fine-grain foam has the maximum specific humidity difference at different operating temperatures. At a high-water flow rate of 80 L/h and low water temperature of 60 °C, the gain output ratio (GOR) is evaluated to be 4.23. Moreover, a solar HDH system includes a solar collector, out of three options, and a thermal storage (TES), and HDH unit is designed and modeled to provide the required heat. For solar collectors, flat-plate, parabolic-trough, and evacuated-tube are considered. It is found that the flat-plate collector has a maximum efficiency of more than 70% while producing over 25 L/d/m2 of distilled water.