Reverse Osmosis Desalination System Research Articles

Multi-criteria optimization next to a comparative analysis of a polygeneration layout based on a double-stage gas turbine cycle fueled by biomass and hydrogen

The significance and advantages of utilizing renewable energy sources are widely recognized. Upon examining past studies, it was revealed that there has been a lack of research on harnessing the waste energy from double-stage gas turbines powered by biomass-hydrogen hybrid fuel for polygeneration applications. Thus, a new configuration is proposed in the study for the multi-production of electricity, cooling, heating, and potable water. In the current research, a high-pressure turbine is driven by a combustion chamber fed by a biomass gasifier. Meanwhile, a low-pressure turbine is driven by a post-combustion chamber fed by hydrogen as fuel. The heat loss of the topping gas turbine cycle is recuperated by a supercritical Brayton cycle (SBC), a steam Rankine cycle (SRC), and a water heater. The waste heat of the supercritical Brayton cycle and steam Rankine cycle is recovered through an absorption refrigeration cycle and a thermoelectric generator, respectively. Thus, the heat loss of the topping system is completely recovered. The net power output of the gas turbine cycle is considered the electricity production of the system while the output power of the SBC and SRC is utilized in a reverse osmosis desalination system to produce potable water. The investigations conducted on the system are thermodynamic and exergy-economic assessments and three-objective optimization utilizing 5 gases (i.e., CO2, CO, Nitrogen, Air, and Helium) in the SBC. The final results reveal the superiority of Helium as the supercritical gas, bringing about an exergy efficiency () of 32.11%, a total cost rate () of 103 , a payback period (PP) of 0.159 years, and a specific cost of polygeneration () of 22.03 for the system. Although the levelized cost of products of the configuration is high due to the freshwater production, of the proposed system is higher than the previous systems based on a double-stage gas turbine cycle driven by biomass and hydrogen.

Optimized multi-criteria performance of a poly-generation layout including a Stirling engine and a supercritical Brayton cycle using biogas and methane as two potential fuels of a topping gas turbine cycle

The combination of a supercritical Brayton cycle, an absorption chiller, a Stirling engine, a reverse osmosis desalination system, and a proton exchange membrane electrolyzer is investigated for waste heat recovery of a topping gas turbine cycle. The required electricity for hydrogen and freshwater production is supplied by the Stirling engine and supercritical Brayton cycle, respectively. In addition, the output power is provided by the gas turbine cycle, and the exiting cold stream of the Stirling engine is considered hot water for domestic utilization. A comparison is made between biogas and pure methane as two possible fuels for the system. Energy and exergy analyses, economic analysis using the specific exergy costing approach, and environmental analysis considering the carbon dioxide emissions are employed in the study. The three-objective optimization of the configuration discloses an exergy efficiency (ηex) of 39.49 % and 39.85 % in the cases of biogas and methane, respectively. The proposed system can improve ηex by 6.18 % points compared to the stand-alone GTC. The specific cost of poly-generation (cpoly) and the total cost rate (C˙tot) are obtained as 25.92 $GJ−1 and 249.5 $h−1 in the biogas mode, while these values are calculated as 36.75 $GJ−1 and 336.7 $h−1 in the methane case. The environmental cost rate (C˙env) of the system is 24.78 $h−1 in the case of biogas and 17.47 $h−1 in the methane mode. The results confirm the superiority of the methane case from the environmental viewpoint over biogas. However, the low values of cpoly and C˙tot in the biogas case indicate that biogas is superior to methane from a general standpoint. The utilization of the present setup for waste heat recovery of biogas-driven GTCs is recommended due to the higher ηex than the previous layouts.

Techno-economic assessment of vertical axis wind turbine driven RO desalination with compressed air energy storage for remote communities

Renewable energy desalination is gaining much attention in remote off-grid communities facing challenges in accessing clean water. Typically, batteries ensure the continuous operation of small-scale renewable reverse osmosis (RO) desalination systems; however, they are expensive and have relatively shorter lifespans. This study investigates the implementation of a compressed air energy storage (CAES) system coupled with a vertical axis wind turbine (VAWT) to directly drive small-scale RO desalination, potentially replacing batteries and reducing energy conversions. A Simulink model was developed to simulate the performance of a VAWT-driven CAES operating RO units, adaptable for both technical and economic assessments. Parametric studies have identified the optimal configuration. The most cost-effective configuration, utilising eleven VAWTs and a pressure exchanger (PX), achieves a levelised cost of water (LCOW) of 1.63 US$/m3 and an annual water production of 9400 m3. The normalised daily water production per square metre of turbine swept area at the study site is 0.19 m3/m2/day at an average wind speed of 5 m/s. While this configuration has a higher initial capital cost, it yields the lowest LCOW. The CAES system effectively addresses the intermittency challenges of wind energy. This study presents a novel, battery-free VAWT-CAES-RO system as a sustainable desalination solution for remote communities, offering a promising approach to address water scarcity in an environmentally friendly manner.

Performance investigation of a novel free piston Stirling pump for reverse osmosis desalination systems

Renewable energy (RE)-powered desalination technology is considered a cleaner and promising alternative for alleviating energy exhaustion and environmental pollution resulting from traditional desalination. Currently available solar thermal reverse osmosis (RO) desalination systems are based on the organic Rankine cycle. With the aim to expand the driving mode of reverse osmosis desalination as well as simplify the transmission chain and reduce mechanical energy losses, a novel hydraulic free piston Stirling pump (FPSP) is developed and a simple model is designed and tested for conceptual validation. A free piston Stirling pump - powered reverse osmosis desalination system is presented, and a thermodynamic–dynamic coupling model is established. A parametric analysis is performed with an emphasis on the effects of temperatures, charge pressure, spring stiffnesses, damping coefficients, and masses on the system performance, including the frequency, power output, water yield, and efficiency. Results showed that the frequency in the pumping process was higher than that in the suction process because of the different loads. Within the range investigated, the performance improved as the hot-end temperature, charge pressure, spring stiffnesses, and damping coefficient of the power piston increased, while it deteriorated with a decrease in the damping coefficient of the displacer and the piston masses. Specifically, the power output and water yield reached the optimum value as the cold-end temperature was maintained around 310 K. Under representative parameter conditions, the power output could reach 12.15 kW and the water yield was approximately 6.07 × 10−4 m3/s. In addition, the temperatures and charge pressure influence the system efficiency most.

A New Algorithmic Method for Reverse Osmosis Desalination Analysis: Design Optimization and Parametric Study

Population growth, coupled with industrial and agricultural development, has resulted in increased demand for freshwater supply. For countries with scarce water resources, desalination constitutes the only viable solution to this problem. Reverse osmosis (RO) technology has become widely used as the membrane materials have been upgraded and the costs have been reduced. Nowadays, RO is the foremost technology for desalting different types of water such as seawater, brackish, and tap water. However, its design is critical since many parameters are involved in obtaining a good design. The high use of RO encourages the establishment of a procedure that facilitates the design process and helps in obtaining an optimum-performance RO desalination system. This paper presents a procedure divided into three parts: (1) classifying RO parameters; (2) choosing the parameters in a certain order and doing the calculation process through 12 steps; and (3) then inserting the selected parameters and the obtained values on RO System Analysis (ROSA) software. These points are then summarized by creating an algorithmic chart to follow during the design phase of the RO system using ROSA. An example on the proposed list is then taken to validate the procedure, and a comparison is conducted on choosing different values for the parameters. The results of this comparative study show that choosing different parameters affects the RO system productivity. Additionally, every design has a specific optimum set of parameters, which depends upon the design constraints set by the user.

Coordinated operation for a resilient and green energy-water supply system: A co-optimization approach with flexible strategies

Sustainable operation of green renewable energy (RE)-powered reverse osmosis (RO) desalination (RE-RO) systems requires co-optimization and smart strategies to reduce costs, losses and enhance system flexibility. This study proposes a decentralized distribution system (DDS) that includes a coordinated multi-objective optimization model with smart strategies for efficient operation and planning of the RE-RO system. The DDS optimizes operation by incorporating demand-side water management (DSWM) and bidirectional regulation (BDR) in the distribution network to minimize operation and emission costs, maximize system resilience, and meet the required demand. Then, sustainable planning strategies are suggested to prioritize relevant technical factors and subfactors for improving the future operation of the DDS based on multi-criteria assessment. With proposed DDS integration, the RE-RO system achieved a 17.4 % reduction in operational costs, a 46.79 % decrease in CO2 emissions, and a 70.96 % improvement in overall system resilience through effective management of water and energy surpluses and deficits. Among the operational planning strategies, the most critical criterion was DSWM-BDR based scheduling, representing 72.09 % of the strategic focus. Thus, the implementation of the proposed coordinated operating and planning strategies can significantly contribute to the development of a sustainable energy-water system, alleviate water scarcity, and facilitate climate change adaptation.

Optimal Sizing and Techno-Economic analysis of Reverse Osmosis Desalination Systems Based on PV/Wind Green Energy System

Optimal Sizing and Techno-Economic analysis of Reverse Osmosis Desalination Systems Based on PV/Wind Green Energy System

Multi-aspect assessment and optimization of a poly-generation layout composed of a geothermal power plant and a wind turbine

The current research is an effort to propose a novel poly-generation layout by hybridization of wind power and geothermal energy as two renewable heat sources. The geothermal unit comprises a steam flash cycle as the topping system and a Kalina flash cycle as the bottoming system. Hot water is produced through the utilization of the energy of the geothermal water before reinjection to the ground. An E126/7580 wind turbine is accountable for generating the favorable output electricity. Moreover, the waste heat from the generator of the wind turbine is recovered in a trilateral flash cycle. The sum of power produced by the steam flash cycle and the trilateral flash cycle is employed to generate hydrogen in an electrolysis unit. Moreover, the output electricity of the Kalina flash cycle is employed to produce cooling and freshwater in a transcritical CO2 refrigeration cycle and a reverse osmosis desalination system. The final evaluation of the system utilizing energy and exergy-economic analyses and three-objective optimization of the layout revealed an exergetic efficiency of 37.11 % in the optimum case. The configuration produces 771.7 kW, 454.3 kW, 3585 kW, 1.29 kgh-1, and 3 kgs-1 of electricity, cooling, heating, hydrogen, and freshwater, correspondingly. The economic analysis of the system indicates a total cost rate of 140.2 $h-1, a specific cost of products equal to 19.5 $GJ-1, and a payback period of 1.03 years, suggesting an excellent economic performance for such a complex system.

Optimizing reverse osmosis desalination from brackish waters: Predictive approach employing response surface methodology and artificial neural network models

A mathematical model frame has been developed to optimize the performance of reverse osmosis (RO) desalination in brackish waters with medium to high salt concentrations using response surface methodology (RSM) and artificial neural network (ANN), specifically catered towards efficiently operating RO desalination systems. The RSM model aims at predicting RO performance with second-order polynomials based on 15 experimental datasets. Inputs for RSM model include feed TDS concentration, feed water flow rate, and concentration-to-desalination ratio, while the outputs consider rejection, membrane flux, performance index, and specific energy consumption. The Genetic Algorithm optimized back-propagation Neural Network was employed to update network weights and biases, leading to an optimal ANN network structure of 3–10-4. A ratio of 70 % training, 15 % validation, and 15 % test data was chosen to establish an ANN model that predicts the performance of RO desalination. The ANN model demonstrated significantly higher prediction accuracy than the RSM model, with impressive correlation coefficients of 0.9936 for the performance index and 0.9932 for SEC prediction, and low RMSE of 0.85 for rejection. To maximize the performance index and minimize specific energy consumption, a two-step optimization method was further set up by applying the RSM model to initially determine optimal process conditions followed by the ANN model to enhance the accuracy of performance forecasts. Optimal process conditions were proposed for specific feed TDS scenarios, which involved setting a feed TDS concentration limit to meet drinking water standards.

Multi-objective optimization and energy efficiency improvement for rotor duct in integrated energy recovery-pressure boost device

To reduce the volumetric mixing rate of the integrated energy recovery-pressure boost device, a novel symmetrical duct structure with diversion surface was proposed. The surrogate model-based multi-objective optimization framework was established, and obtained the optimal ducts V1 and V2 combined with computational fluid dynamics simulation. Numerical results indicate that optimized duct structure could promote the formation of plug flow and effectively improve the collision efficiency between high-pressure brine and low-pressure seawater, and the volumetric mixing rate corresponding to the ducts V1 and V2 was reduced by 31.52% and 22.18%, and the duct volume efficiency was increased by 16.04% and 19.56%, respectively. Finally, the performance of optimized device was verified through seawater reverse osmosis desalination system under actual working conditions. Experimental results showed that the mixing rate of optimized ducts had a significant decrease of 30.86% and 20.53% in the applicable range, and the energy recovery efficiency improved at most 5.41% and 7.55%, respectively. The optimized ducts could significantly reduce the specific energy consumption of the desalination system by 26.01% and 18.22%, respectively, and the specific energy consumption reached the lowest level of 3.02 kWh/m3, demonstrating the superiority of the structure and the accuracy and effectiveness of the optimization strategy.

Techno-Economic Feasibility of Reverse Osmosis Desalination Scale Coupled with Solar Energy: Case of Algeria

B Brackish water and seawater desalination have become important freshwater sources in arid and semi-arid regions suffering from water scarcity. Fortunately, the availability of solar energy provides an excellent opportunity to replace conventional energy with renewable energy for desalination system power. However, technical and economic feasibility studies must be carried out according to the characteristics of each region to assess its economic feasibility. This study assessed the techno-economic feasibility of a solar-powered desalination small-scale BWRO with a capacity of 2.016 m3/day. Two scenarios were proposed: a desalination station powered by a public network without a solar energy system (On-Grid) and a second powered by photovoltaic panels (Off-Grid). The result shows that the water production cost of the Off-Grid system (0.33 $/m3) was about 1.14 times lower than the water production cost of the On-Grid system (0.38 $/m3). The economic analysis result shows that the reverse osmosis desalination system coupled with a photovoltaic system (Off-Grid) is an economically suitable option for satisfying the increasing freshwater product demand compared to the grid-powered system (On-Grid), especially in arid areas.

Development, growth, and function of biofilm communities on reverse osmosis membranes desalinating tertiary effluent

Efficient tertiary effluent desalination is hindered by membrane biofouling, leading to plant downtime, shortened membrane lifespan, heightened energy consumption, and reduced permeability. While the composition of these biofouling layers is studied, little is known about bacterial succession and function. To address this, we used a benchtop reverse osmosis (RO) system to process synthetic tertiary effluent with diluted sludge. System flux monitoring tracked biofouling layer development, and RO biofilm samples were collected at early and mature stages (48, 72, 120 h). Scanning electron microscopy visualized the samples, and their 16S rRNA genes were sequenced. DNA-stable isotope probing with labeled glucose identified growing taxa in early and late biofouling stages (48, 120 h). Over time, biofouling layer biomass increased, with shifts in bacterial diversity and composition. Proteobacteria, notably oligotrophic genera, dominated early stages along with Bacteriodota, while Actinobacteria increased in mature biofilms. Functional changes included a shift from biosynthesis of cellular components like DNA, peptidoglycan, membrane lipids, and antimicrobials, to production of extracellular polysaccharides and reactive oxygen scavenging agents. In conclusion, our research enhances the understanding of biofouling dynamics within tertiary effluent desalination processes, providing insights that could improve biofouling management strategies in RO desalination systems, potentially applicable to larger-scale operations.

Techno-exergy-economic assessment of humidification-dehumidification/reverse osmosis hybrid desalination system integrated with concentrated photovoltaic/thermal

Desalination is a process used to generate water for human consumption, irrigation, or industrial purposes. Assessment of desalination plants is crucial for freshwater productivity, energy consumption, exergy destruction, and economic feasibility calculations. Therefore, the study aims to conduct a technical, exergy, and economic analysis of a concentrated photovoltaic/thermal hybrid humidification-dehumidification reverse osmosis desalination system. The photovoltaic/thermal provides the electrical and thermal requirements for the hybrid desalination unit. Theoretical models for each unit are developed and integrated using the Engineering Equation Solver software. The sensitivity of system performance parameters was investigated under different climatic and operation factors. The analysis shows that the system produces 860 L per hour at the lowest specific energy consumption and water cost (3.3 kW-hours per cubic meter and 0.916 United States dollars per cubic meter), respectively, with a cost payback period of only 12 years compared to other green-powered desalination systems. The highest destruction portion of 84.6 % is at photovoltaic/thermal, while the largest cost portion of 68 % is at reverse osmosis. Productivity, energy consumption, and water cost are influenced by feed salinity, while destruction is most affected by solar irradiance. Ambient temperature, wind speed, and cooling fluid flow rate slightly affect the techno-exergy-economics of the system.

Operation strategy optimization of an integrated proton exchange membrane water electrolyzer and batch reverse osmosis desalination system powered by offgrid wind energy

Operation strategy of the integrated wind-hydrogen system is the key to ameliorate the negative impacts of the fluctuated wind power on the hydrogen production capacity and durability ofelectrolyzer. However,the desalination system supplying pure water to electrolyzers was neglectedpreviously, with which the practical operation strategy of the hybrid wind-hydrogen-desalination system has yet to be investigated. In this work, we proposed a novel control strategy named step-by-step start for wind-hydrogen-desalination system consisting of wind turbine, proton exchange membrane water electrolyzer (PEMWE), battery and batch reverse osmosis (BRO) desalination system, which can produce hydrogen andfresh water. Real-time wind data from Shenzhen, Chinawere used as input to the integrated system. The results demonstratethe wind-hydrogen-desalination system with the proposed strategy can improve the hydrogen production by 17.55 %, the energy efficiency by 17.68 % in August, and increase hydrogen production by 10.29 %, the energy utilization efficiency by 10.44 % in December compared with traditional strategies. At low wind speeds, the switching times of PEMWE for this strategy is higher than the other strategies, while at high wind speeds, the switching times of PEMWE is significantly decreased. This work provides insights into the practical operation strategy for wind-hydrogen-desalination system depending on the real-time wind speed.

Conceptual design and 4E analyses of a tetrageneration system in two different configurations based on poplar sawdust as a local woody biomass fuel

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

Design and performance analysis of thermal assisted reverse osmosis (RO)

Abstract Today, the world is facing difficult challenges related to water scarcity and freshwater resources. Water desalination has become necessary to meet this great demand. The reverse osmosis desalination system is considered the dominant type of desalination, although the high amount of energy consumed is considered the main barrier to expanding seawater reverse osmosis (SWRO). The need for producing an environmentally friendly energy source is also one of the most important challenges in preserving the environment and reducing global warming. The coexistence of power plants that release waste heat energy through the condenser and reverse osmosis plant represents an opportunity for a synergy system. Therefore, research has shown that the low/ultralow grade heat from natural sources or industrial processes can assist the process of desalination. This paper reviews available process configurations, system design, and operating parameters, and discusses the performance of the RO process at high temperatures.

Investigation of water-cooled photovoltaic driven reverse osmosis desalination system

Investigation of water-cooled photovoltaic driven reverse osmosis desalination system

Hybrid desalination system for Baltic Sea water: A preliminary study

The world's water resources predominantly comprise salt water. In the face of forecasts of increasing demand for hydrogen obtained by electrolysis, it is becoming important to investigate the feasibility of seawater desalination. As part of a research project, the possibility of using a hybrid zero liquid discharge (ZLD) desalination system to desalinate seawater from the Baltic Sea was examined. In addition to analysing the operating parameters of the system, a detailed physico-chemical examination of the process water was carried out at each stage of treatment. It was found that the reverse osmosis (RO) and multiple-effect desalination (MED) systems allow sufficient water parameters to be obtained to feed the ion exchange (IX) system, and after deionisation it is possible to achieve the water parameters required by proton exchange membrane (PEM), anion exchange membrane (AEM) and alkaline water (AWE) electrolysers. Furthermore, the possibilities of concentrating brine in the multiple-effect desalination system and extracting salt in solid form in the ZLD system were verified.

Development of a generalized mathematical model for two-stage reverse osmosis desalination systems

This study presented a generalized mathematical model for a two-stage reverse osmosis (RO) system based on mass balance, the solution-diffusion model, and film theory. The model is user-friendly and can be customized for any membrane regardless of the manufacturer. A set of non-linear equations was solved in MATLAB to calculate the system arrangement, performance parameters, and the required feed pressure for the desired recovery ratio by incorporating membrane characteristics and design parameters. Actual data from a two-stage RO system were employed for model validation against ROSA software results. To optimize energy conservation, equal recovery rates are applied to both stages, resulting in lower calculated feed pressures than those obtained using ROSA software. The study reveals a strong agreement between the simulation results and those obtained from the ROSA software and alignment with the membrane manufacturer's recommendations, making the model a reliable tool for evaluating the system before implementation.

A novel hybrid reverse osmosis and flash desalination system powered by solar photovoltaic/thermal collectors

A novel hybrid reverse osmosis and flash desalination system powered by solar photovoltaic/thermal collectors