Seawater Desalination Plant Research Articles

Power Generation Performance of a Pilot-Scale Reverse Electrodialysis Using Monovalent Selective Ion-Exchange Membranes.

Reverse electrodialysis (RED) is a promising process for harvesting energy from the salinity gradient between two solutions without environmental impacts. Seawater (SW) and river water (RW) are considered the main RED feed solutions because of their good availability. In Okinawa Island (Japan), SW desalination via the reverse osmosis (RO) can be integrated with the RED process due to the production of a large amount of RO brine (concentrated SW, containing ~1 mol/dm3 of NaCl), which is usually discharged directly into the sea. In this study, a pilot-scale RED stack, with 299 cell pairs and 179.4 m2 of effective membrane area, was installed in the SW desalination plant. For the first time, asymmetric monovalent selective membranes with monovalent selective layer just at the side of the membranes were used as the ion exchange membranes (IEMs) inside the RED stack. Natural and model RO brines, as well as SW, were used as the high-concentrate feed solutions. RW, which was in fact surface water in this study and close to the desalination plant, was utilized as the low-concentrate feed solution. The power generation performance investigated by the current-voltage (I–V) test showed the maximum gross power density of 0.96 and 1.46 W/m2 respectively, when the natural and model RO brine/RW were used. These are a 50–60% improvement of the maximum gross power of 0.62 and 0.97 W/m2 generated from the natural and model SW, respectively. The approximate 50% more power generated from the model feed solutions can be assigned to the suppression of concentration polarization of the RED stack due to the absence of multivalent ions.

Modeling, simulation, and optimization of the membrane performance of sea-water reverse osmosis desalination plant using neural network and fuzzy based soft computing techniques

Modeling, simulation, and optimization of the membrane performance of sea-water reverse osmosis desalination plant using neural network and fuzzy based soft computing techniques

Sustainability assessment and environmental impacts of water supply systems: a case study in Tampa Bay water supply system

Due to the accelerated industrial and urbanization development, climate change, and increasing populations and life quality expectations, the issue of drinking water shortage has raised much public awareness. The desalination system has been widely applied to accommodate the growing demand for clean water resources despite the continuous concerns about its relatively higher energy consumption and environmental footprints. This research conducted a case study in the Tampa Bay Regional Surface Water Treatment Plant and Tampa Bay Seawater Desalination Plant in Florida, U.S. It analysed the performance and environmental impacts of conventional and desalination water supply systems on three sides: energy consumption, carbon footprint, and solid waste. Potential negative effects of both water supply systems are generally associated with surface water ecology, groundwater aquifers, coastal environment, and marine organisms. Various environmental impact mitigation plans have been proposed to prevent or restore the detriments caused by carbon dioxide emissions, plant construction, and concentrated brine discharge. Due to the deficiency in freshwater resources, desalination technology is more promising through proper regulations and regional sustainable development.

Test method of seawater desalination plant based on information fusion

Test method of seawater desalination plant based on information fusion

Integration of a Combined Cycle Power Plant with MED-RO Desalination Based on Conventional and Advanced Exergy, Exergoeconomic, and Exergoenvironmental Analyses

The ever-increasing world population, change in lifestyle, and limited natural water and energy resources have made industrial seawater desalination plants the leading contenders for cost-efficient freshwater production. In this study, the integration of a combined cycle power plant (CCPP) with multi-effect distillation (MED) and reverse osmosis (RO) desalination units is investigated through comprehensive conventional and advanced exergy, exergoeconomic, and exergoenvironmental analyses. Firstly, the thermodynamic modelling of the CCPP is performed by using a mathematical programming procedure. Then, a mathematical model is developed for the integration of the existing CCPP plant with MED and RO desalination units. Finally, conventional and advanced exergy, exergoeconomic, and exergoenvironmental analyses are carried out to assess the main performance parameters of the integrated CCPP and MED-RO desalination system, as well as to identify potential technical, economic, and environmental improvements. A case study is presented based on the Shahid Salimi Neka power plant located at the north of Iran along the Caspian Sea. The mathematical modelling approach for the integrated CCPP and MED-RO desalination system is solved in MATLAB, and the results are validated via Thermoflex software. The results reveal an increase of 3.79% in fuel consumption after the integration of the CCPP with the desalination units. The exergy efficiency of the integrated system is 42.7%, and the highest cost of exergy destruction of the combustion chamber is 1.09 US$ per second. Economic and environmental analyses of the integrated system also show that gas turbines present the highest investment cost of 0.047 US$ per second. At the same time, MED exhibits the highest environmental impact rate of 0.025 points per second.

Evaluating maintenance strategies using a resilience index in a seawater desalination plant

Sustainability of industrial systems depends largely on the availability of fresh water. Therefore, the scarcity of this resource has led to the installation of several seawater desalination plants worldwide. The dependability and criticality of these plants increases the demands for systems' availability and reliability. An important intrinsic characteristic of these plants is their capacity to react robustly to shocks and to recover their operation in the face of any type of disruptive event. Resilience, therefore, is a first-order metric that must be present in every maintenance-related decision-making process. Different resilience assessment methods have been applied to various engineering systems and networks. Nevertheless, no quantitative assessment of the resilience in seawater desalination plants has been reported in the literature so far. This work proposes the adaptation and application of an availability-based resilience index using reliability block diagrams and Montecarlo simulations experiments. Besides, an application study in an actual seawater desalinization plant is provided. The main results of this work point to that different maintenance strategies cause different impact in system's availability, and that the definition of such strategies could be made considering their impact on system's resilience.

Identification of bacterial biofilms on desalination reverse osmosis membranes from the mediterranean sea

Nanofiltration and reverse osmosis are two of the most effective surface water treatment processes. They provide water of high quality and eliminate a large amount of microorganisms, organic matter and micropollutants. However, the main limitation of membrane nanofiltration is fouling, which imposes an additional cost. This study focused on the search for microorganisms capable of reducing the performance of nanofilters and also to study autoaggregation and biofilms formation by bacterial strains isolated from the nanomembranes used in the seawater desalination plant of Souk Tlata (Algeria). It provides new microbiological data on the desalination of seawater in the southern Mediterranean basin. The results revealed 14 bacterial species isolated from six fouled reverse osmosis membranes; their quantities were significant with the dominance of Raoultella sp., Klebsiella sp., Staphylococcus sp., Stenotrophomonas sp., Micrococcus sp., and Escherichia coli. In addition, electron imaging of nanomembrane surfaces revealed complex structures of microorganisms forming biofilms.

Identification, extraction of microplastics from edible salts and its removal from contaminated seawater

Microplastics (MPs) present in edible salts may create a potential health hazard for humans. The occurrence of MPs in edible salts and their extraction procedure is limited. In this work, we have developed a facile and cost-effective protocol for the extraction and separation of MPs from the edible salt sample. The visual assessment was performed to identify the shape, size, number, and color of microplastic particles using light and fluorescence microscopy. The composition of the sample was analyzed by micro-Raman spectroscopy. A wide range of MPs were found: 1400 ∼1900 particles/kg in refined sea salt, 1900 ∼2300/kg in unrefined sea salts, and 200 ∼400/kg in rock salts. A relatively high number of MPs were found in sea salts rather than rock salts. Sheet type MPs with size 1 ∼ 4μm were observed in rock salts. The most common MPs were polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), nylon, and polystyrene (PS). Further, MPs were effectively removed from synthetic seawater with the help of a microfiltration membrane, which has the capability of arresting the transfer of microplastic particles into edible salts. Therefore the use of MF/UF pretreated brine from seawater desalination plant can be explored for MPs sea salt production at low cost.

Organic compounds and microbial assessment of a seawater reverse osmosis facility at Tampa Bay Water, USA

The Tampa Bay Water seawater reverse osmosis (SWRO) facility is the first large-capacity seawater desalination plant in the United States. The feedwater source for the facility is an estuarine system that is biologically very productive and contains naturally-occurring high concentrations of algae, marine bacteria, total organic carbon (mostly dissolved), transparent exopolymer particles (TEP), the biopolymer fraction of natural organic matter, and phosphate. The high-organic composition of the feedwater places stress on the conventional sand pretreatment system utilized at the facility resulting in high organic passage into the membrane process and flow through into the permeate. In particular, the direct passage of particulate TEP (p-TEP) into the membranes has a major impact on the biofouling rate. Based on the data collected, the pretreatment is ineffective at removing key organic components that impact the rate of membrane biofouling, particularly bacteria and p-TEP. Perhaps the pretreatment could be re-designed to use a dissolved air floatation system (DAF) followed by ultrafiltration as a remedy that would likely move the biofouling problem to the ultrafiltration process, which has an easier cleaning process. Consideration could be given to using a groundwater source of feedwater as a permanent remedy to the operational issues.

Energy-water nexus in seawater desalination project: A typical water production system in China

As the most essential factors affecting sustainable regional development, energy and water resources are closely related. Based on the three-scale energy intensity database, this study calculates the whole life cycle performance of a 25,000 tons/day desalination project in Hebei Province, China by combining life cycle analysis with input-output analysis. Considering the embodied energy consumption in different time periods, the corresponding freshwater production per year is 9.13 million m3, and the total energy consumption covering the construction and operation stages is 39.46 PJ, with the energy consumption per year of 1.94 PJ. Considering the embodied energy consumption in different scales and components, the energy consumption at the national scale contributes the largest proportion (68.79%), and the evaporator is the main component in the construction stage (34.30%). For energy consumption in water production, the energy-water nexus index in the project is 18.02 kWh/m3, among which the thermal power could be replaced through the combination of seawater desalination and thermal power plants. Through the reasonable selection of key materials and components and location of seawater desalination projects, the balance between the supply and demand of energy consumption and water production could be optimized from the energy-water nexus perspective.

A Small RO and MCDI Coupled Seawater Desalination Plant and Its Performance Simulation Analysis and Optimization

To solve the problems of high specific energy consumption and excessive harmful ions in the water production of a small reverse osmosis (RO) plant, a desalination system coupling RO and membrane capacitive deionization (MCDI) is proposed in this study. Aiming at producing two cubic meters per day of fresh water with a salt concentration of less than 280 mg L−1, parameter matching optimization was carried out on two desalination system schemes of one-stage two-section RO and one-stage three-section RO coupled with MCDI. The results were compared with the parameter matching optimization results of the one-stage one-section RO and the one-stage two-section pure RO desalination system. The results show that compared with the pure RO desalination mode, the seawater desalination mode coupled with RO and MCDI reduces the specific energy consumption under the same effluent salt concentration. Moreover, it decreases the feed water pressure in front of the RO membrane, which can reduce the standard of high-pressure pump in a small seawater desalination plant. The energy consumption of the one-stage three-section RO and MCDI coupling system is lower than that of the one- stage two-section RO and MCDI coupling system, and the feed water pressure is also lower.

Metode optimasi pada interkoneksi sistem suplai uap untuk kehandalan dan ekonomi pada sea water desalination

Sea water desalination or desalination plant is an equipment that functions to change sea water into fresh water. Its reliability in supply water is important especially as raw material for the electricity generation process. Start-stop gas turbine operating mode as well as routine maintenance schedules or sudden damage in one of the desalination plant s cause a reduction in steam supply readiness. This research purposed to maintain the availability of supply steam desalination plant by using a method design interconnection line which is analyzed in terms of pressure drop and flow in theoretical calculations. This research resulted is design the interconnection line supply steam of the desalination plant by removing and modifying the position of the check valve dividing between desalination plant 1, 2 and 3. The analysis of the supply steam interconnection design in terms of pressure and flow desalination plant is still in accordance with the reference manual book. The operational cost of the desalination plant is more economical using supply steam from Block 1 Low-Pressure Auxiliary with a profit of 154.01% or 82,318,148 rupiahs per day. Keywords: Sea water desalination, interconnection line, pressure drop, flow, operational cost.

Analysis of hydraulic system for seawater desalination plant through piping analysis program

Analysis of hydraulic system for seawater desalination plant through piping analysis program

Power generation performance of a bench-scale reverse electrodialysis stack using wastewater discharged from sewage treatment and seawater reverse osmosis

In this study, we evaluated steady state power generation performance of a bench-scale RED stack with an effective membrane area of 40 m2 under different flow rate conditions using brine discharged from a seawater desalination plant and water discharged from a sewage treatment plant. Constant current operation was enabled to evaluate the steady state power output of the stack as the salt concentration profile inside the stack approached equilibrium. In addition, external current loading allowed for measurements of respective resistance of the stack, including membrane resistance, solution compartment resistance with spacers, and the resistance of each electrode; these measurements allowed for an estimation of the intrinsic stack performance when the electrode resistance was negligible. The evaluation of energy conversion efficiency revealed that 25–66% of the salinity gradient energy (SGE) was consumed in the stack and converted to electricity with a conversion efficiency of 17–26%. Furthermore, energy conversion analysis while considering the SGE loss due to both salt leakage and electrode reaction showed an energy conversion rate of 50%. Finally, the existence of flexible membrane deformation was proposed under different flow rates to obtain higher net power output. The obtained results are promising for use in full-scale RED implementation.

Modelling demand flexibility and energy storage to support increased penetration of renewable energy resources on Porto Santo

AbstractThis paper assesses the contribution of a controllable load (a reverse osmosis [RO] seawater desalination plant), together with an energy storage system in Porto Santo's small islanded electric power system. The controllable load and storage system are used to (i) smooth the net‐demand fluctuations and adapt it to the availability of renewable energy sources (RES), thus avoiding possible curtailments and contributing to a higher dissemination of RES, (ii) minimize the overall operational cost associated with the production of electricity and potable‐water, and (iii) reduce the environmental pollutants associated with the electric power systems on the island. The nonlinear nature of the problem makes it difficult to quickly obtain a robust solution through conventional mathematical tools. Therefore, an evolutionary algorithm is developed to find feasible solutions for dispatching the resources for a one‐week simulation period. The proposed algorithm determined the power output of the conventional thermal power plant, the RO desalination plant operating periods, and the storage charging and discharging periods and powers. In the proposed scenario, through a seven‐day simulation, 50% of the demand is supplied by renewable sources. The numerical results illustrate a reduction in the average total electricity‐peak demand of the island. The obtained diagrams are compared with the data gathered on Porto Santo's energy system. They display that the proposed solution is economically beneficial for the management of the electric power grid of the island of Porto Santo, while reducing the global warming potential (GWP) of the electric power system. Furthermore, it reveals that in a scenario with 50% penetration of renewable sources, through the proposed solution, a more efficient and predictable operation of the conventional electricity generators and the RO desalination plants can be achieved. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.

Influences and impacts of biofouling in SWRO desalination plants

The ability to produce fresh potable water is an ever-growing challenge, especially with an increase in drought conditions worldwide. Due to its capacity to treat different types of water, reverse osmosis (RO) technology is an increasingly popular solution to the water shortage problem. The major restriction associated with the treatment of water by RO technology is the fouling of the RO membrane, in particular through biofouling. Membrane fouling is a multifaceted problem that causes an increase in operating pressure, frequent cleaning and limited membrane lifespan. The current paper summarizes the impact of biofouling of RO membranes used in seawater desalination plants. Following a brief introduction, the elements that contribute to biofouling are discussed: biofilm formation, role of extracellular polymeric substances (EPS), marine environment, developmental phases of biofouling. Following this, is a section on the implications of membrane biofouling especially permeate flux and salt rejection. The final section focuses on the new phenomenon of compression and hydraulic resistance of biofilms. Lastly, considerations on future research requirements on biofouling and its control in seawater reverse osmosis (SWRO) membrane systems are presented at the end of the article.

Toward a Sustainable Decentralized Water Supply: Review of Adsorption Desorption Desalination (ADD) and Current Technologies: Saudi Arabia (SA) as a Case Study

Several regions are confronting a severe scarcity of fresh water due to the gap between supply and demand. They strive to bridge that gap by depleting nonrenewable water aquifers and expanding centralized energy-intensive desalination technologies. Continuing to adopt the same unsustainable approach could deplete the water aquifers and increase the consumption of fossil fuel and the ecological impact on air, water, and land. However, the traditional paradigm of centralized desalination systems could be shifted by increasing the utilization of renewable distributed generation, which can be coupled with emerging desalination technology such as adsorption desorption desalination (ADD), which has autonomous and resilient attributes that can contribute to the sustainability of decentralized fresh water supply in the future. In this work, three commercialized desalination technologies were reviewed and compared with emerging ones to explore the most economically and environmentally efficient systems within the context of decentralized water production. The well-known configurations of ADD were evaluated and compared with sea water reverse osmosis (SWRO), which is recognized as the principal commercialized desalination technology worldwide. The quantitative case study methodology was used by investigating four centralized seawater desalination plants in Saudi Arabia (SA) with their associated pipeline systems from the energy consumption point of view to determine the applicability of implementing ADD technology in SA and similar arid areas. The study reveals that adopting decentralized ADD technology coupled with renewable energy sources could reduce the specific energy consumption from 4 kWh/m3 to less than 1.38 kWh/m3. Combining reduced energy consumption from desalination plants and elimination of supply pipelines could potentially result in a significant reduction in energy consumption and carbon emissions. Finally, the study may be useful for researchers working on enhancing ADD processes, as well as technology users who would like to implement the most efficient ADD configurations. Additionally, it may initiate a direction of utilizing the results of original critical reviews as a methodology to develop the applied technologies.

Fouling behavior of marine organic matter in reverse osmosis membranes of a real-scale seawater desalination plant in South Korea

The effects of marine organic matter (MOM) characteristics on the fouling layer composition of seven parallelly arranged reverse osmosis (RO) membrane modules were identified to offer valuable insights into the fouling behavior of MOM in a real-scale seawater desalination plant in the South Korea region. Although both hydrophobic (HPO) and hydrophilic (HPI) MOM fractions governed the fouling formation of the RO membranes, HPO MOM fractions complexed with multivalent metal ions (i.e., Al, Ca, Cu, Fe, and Mg) were found to be major contributors to the irreversible fouling of the RO membranes. Despite the efficient recovery of the negative surface zeta potential after the cleaning procedures with deionized water, base and acid solutions, the contact angle of the fouled RO membrane was reduced significantly, which was more pronounced for the cleaned RO1st membranes than the cleaned RO7th membranes. HPI MOM fractions were preferentially deposited onto the membrane surfaces in the RO1st module, while residual HPO MOM fractions strongly contributed to the fouling formation of the RO membranes in the RO7th module. These phenomena might lead to significant differences in the fouling layer composition of the RO membrane modules in the real-scale seawater desalination plant in the South Korea region.

An Optimal Sizing of Stand-Alone Hybrid PV-Fuel Cell-Battery to Desalinate Seawater at Saudi NEOM City

NEOM City in Saudi Arabia is planned to be the first environmentally friendly city in the world that is powered by renewable energy sources minimizing CO2 emissions to reduce the effect of global warming according to Saudi Arabia’s Vision 2030. In recent years, Saudi Arabia has had a problem with water scarcity. The main factors affecting water security are unequal water distribution, wrong use of water resources and using bad or less efficient irrigation techniques. This paper is aimed to provide a detailed feasibility and techno-economic evaluation of using several scenarios of a stand-alone hybrid renewable energy system to satisfy the electrical energy needs for an environmentally friendly seawater desalination plant which feeds 150 m−3 day−1 of freshwater to 1000 people in NEOM City, Saudi Arabia. The first scenario is based on hybrid solar photovoltaic PV, fuel cells (FC) with a hydrogen storage system and batteries system (BS), while the second and third scenarios are based on hybrid PV/BS and PV/FC with a hydrogen storage system, respectively. HOMER® software was used to obtain the optimal configuration based on techno-economic analysis of each component of the hybrid renewable energy systems and an economic and environmental point of view based on the values of net present cost (NPC) and cost of energy (COE). Based on the obtained results, the best configuration is PV/FC/BS. The optimal size and related costs for the optimal size are 235 kW PV array, 30 kW FC, 144 batteries, 30 kW converter, 130 kW electrolyzer, and 25 kg hydrogen tank is considered the best option for powering a 150 m3 reverse osmosis (RO) desalination plant. The values of net present cost (NPC) and the cost of energy (COE) are $438,657 and $0.117/kWh, respectively. From the authors’ point view, the proposed system is one among the foremost environmentally friendly systems to provide electric energy to the seawater desalination plant, especially when connecting to the utility grid, because it is ready to reduce a large amount of greenhouse gas emissions due to using oil/nature gas in utility generation stations to reduce the effect of global warming.

Combined concentrated solar power plant with low-temperature multi-effect distillation

This study analyzes a technological concept for simultaneously generating power and desalinating water in a Middle East and North Africa country. An innovative, low-temperature, multi-effect desalination (LT-MED) process integrated with a concentrating solar power (CSP) plant was assessed and analyzed. A combined power and seawater desalination plant was modeled for the city of Aqaba by the Red Sea in Jordan. Parabolic-trough collectors using indirect steam generation with thermal energy storage connected with power and desalination blocks were designed. The designed plant was modeled and simulated using EBSILON Professional, a discrete energy balance simulation software, under several operating conditions, to analyze the results. An economic feasibility analysis of the combined CSP+LT-MED plant was also conducted. The simulation results showed the broad variability of the cogeneration system in terms of electricity generation and water production. The output power of the CSP plant without water production reached 58.7 MWel in June. The output power accompanied with distilled-water production with a mass flow rate of 170 m3/h was approximately 49.5 MWel. Furthermore, the number of desalination stages had the strongest influence on distillate production but limited the operational flexibility of the power plant due to the temperature gradients within the desalination stages. The distilled-water mass flow reached 498 m3/h for 10 stages. The research showed that the design successfully worked with up to €78.84 million, earned from selling the produced electricity. However, owing to highly subsidized water tariffs in Jordan (80% less than the actual cost), the integration of water desalination into the CSP plant was not economically feasible.