A solar multiple effect distiller for Jordan

Brackish water desalination by a stand alone reverse osmosis desalination unit powered by photovoltaic solar energy

Energy cost contributes a large portion of the overall cost of desalinated water. Improving the energy efficiency of desalination plants is therefore a primary design goal. However, accurately evaluating and comparing the energy consumption of desalination plants that use different forms and grades of energy is difficult, especially for power–water coproduction systems in which primary energy (PE) consumption leads to both salable electricity and potable water. The power plant converts PE into grades of thermal energy and electricity usable by the desalination plant. To fully capture the thermodynamic and economic cost of energy, and to fairly compare desalination systems that use different grades of input energy, we must compare energy consumption not at the point where energy enters the desalination plant itself, but as PE consumption entering the power plant. This paper investigates a variety of metrics for comparing the energy and exergy consumption attributable to desalination in coproduction plants. Previous results have shown that reverse osmosis (RO) is approximately twice as efficient as multiple effect distillation (MED) on a PE basis. We then compare the PE consumption of MED and RO from a thermoeconomic perspective. The entropy generation at the RO membrane and in the MED effects are derived in similar terms, which enables a comparison of the overall heat transfer coefficient in an MED system to the permeability of an RO membrane. RO outperforms MED in energy efficiency because of a balance of material costs, transport coefficients, and cost of energy.

Over the past decade, the author, Roger Francis, has looked at some very expensive corrosion failures in desalination plants. Avoiding Corrosion in Desalination Plants tells the reader how to avoid existing corrosion problems and how to avoid them in new builds. This book looks at corrosion problems specific to MSF, MED, and SWRO desalination plants, describing their causes, some solutions, and the relative performance of various materials. It gives advice on procuring materials for desalination plants to avoid quality problems. The world’s population is steadily increasing and with it is an increasing demand for water—for both drinking and irrigation. In many areas of the world, particularly in warmer climates, there are limited sources from rivers and wells, so desalination is being increasingly used to produce water to satisfy both requirements. Although desalination is sometimes carried out on brackish waters and highly saline well waters, most desalination plants generate fresh water from seawater. There are three main processes used in desalination plants, the oldest of which is multistage flash (MSF), where the water is essentially boiled at low pressure and the steam that flashes off is condensed for drinking water. The second process is multiple-effect distillation (MED), in which low-pressure steam is used to force evaporation of seawater and the vapor is then condensed for drinking water. Although actual MSF and MED plants (large-scale) are land based, small-scale units have been fitted to large ships, such as cruise liners, to generate fresh water. The third process is seawater reverse osmosis (SWRO), where chloride is selectively removed from water by forcing it at high pressure through a special membrane. This method involves no heat transfer but requires enough electricity to power the high-pressure pumps that are required. All three of these methods have advantages and disadvantages. This book looks at corrosion problems specific to MSF, MED, and SWRO desalination plants, describing their causes, some solutions, and the relative performance of various materials. It gives advice on procuring materials for desalination plants to avoid quality problems.

Impact of desalination plants fluid effluents on the integrity of seawater, with the Arabian Gulf in perspective

Membrane distillation (MD) is a desalination technique that consumes a lot of energy compared to reverse osmosis or multiple effect distillation. Nevertheless, MD requires relatively low-temperature heat that can be recovered at the condenser of a cooling system. Experiments have shown that distilled water production increases with the feed water temperature. The transcritical CO2 cycle and its ability to produce hot water at a higher temperature at low expense is an asset for MD. A numerical model was built using EES software. A simulation study presents the expected performance of a CO2 heat pump for simultaneous cooling and desalination. In some operating conditions, the freshwater production is more than doubled compared to standard heat pumps. The specific energy consumption per cubic meter of distilled water is still higher than with reverse osmosis. However, energy and exergy analyses considering freshwater and cooling productions show promising research paths.

There are direct links between water and energy use, sometimes referred to as the energy-water nexus. Water rights issues have confronted the southwestern U.S. for a long time. Furthermore, climate change is decreasing the already limited water resources in this region, and the growing population in the Southwest has also increased the consumption of freshwater. Here we study solar energy, which is abundant in the Southwest, as both an electric power source and the energy source to operate a desalination plant. We compare the use of different desalination technologies for seawater and brackish groundwater, which have different salinities. The data show that the dual-purpose reverse osmosis desalination plant is the most economical choice. However, since a multiple-effect desalination (MED) and a multistage-flash (MSF) can use waste heat for water production, desalinated water becomes a byproduct of the electric power plant, thus dual-purpose MED and MSF plants will be more economical than a single-purpose power plant. A MED plant using seawater or brackish water produces fresh water for $1.73/m3, while the costs are $2.81/m3 and $2.65/m3 for a MSF plant using seawater and brackish water, respectively.

Introduction of an efficient small-scale freshwater-power generation cycle (SOFC–GT–MED), simulation, parametric study and economic assessment

Impact of phosphonium-based ionic liquid on the corrosion control of aluminum alloy AA5052 in MED desalination plants during acid cleaning process

The engineering of solar power applications, such as photovoltaic energy (PV) or thermal solar energy requires the knowledge of the solar resource available for the solar energy system. This solar resource is generally obtained from datasets, and is either measured by ground-stations, through the use of pyranometers, or by satellites. The solar irradiation data are generally not free, and their cost can be high, in particular if high temporal resolution is required, such as hourly data. In this work, we present an alternative method to provide free hourly global solar tilted irradiation data for the whole European territory through a web platform. The method that we have developed generates solar irradiation data from a combination of clear-sky simulations and weather conditions data. The results are publicly available for free through Soweda, a Web interface. To our knowledge, this is the first time that hourly solar irradiation data are made available online, in real-time, and for free, to the public. The accuracy of these data is not suitable for applications that require high data accuracy, but can be very useful for other applications that only require a rough estimate of solar irradiation.

Alternatives of steam extraction for desalination purposes using SMART reactor

Advancing solar-powered hybrid FO-MD desalination: Integrating PVT collectors and PCM for sustainable water production in residential building

Multi-criteria sustainability assessment of water desalination and energy systems — Kuwait case

Desalination is the production of fresh potable water from a saline water source (seawater or brackish water) via membrane separation or evaporation. Desalination plants operate in more than 120 countries worldwide, and some desert states, such as Saudi Arabia and the United Arab Emirates, rely on desalinated water for more than 70% of their water supply. Sea or brackish waters are typically desalinated using two general types of water treatment technologies—thermal evaporation (distillation) and membrane separation. All thermal desalination technologies use distillation (heating of source water) to produce water vapor that is then condensed into low‐salinity potable water. The thermal desalination technologies most widely used today are multistage flash distillation (MSF), multiple effect distillation (MED), and vapor compression (VC). Membrane desalination is a process of separating minerals from source water using semipermeable membranes. Two general types of technologies are currently used in membrane desalination—reverse osmosis (RO) and electrodialysis (ED). Reverse osmosis desalination is the most widely used membrane separation process today. Currently, there are more than 2000 RO membrane seawater desalination plants worldwide whose total production capacity is in excess of 3 million cubic meters per day (800 MGD).

The engineering of solar power applications, such as photovoltaic energy (PV) or thermal solar energy requires the knowledge of the solar resource available for the solar energy system. This solar resource is generally obtained from datasets, and is either measured by ground-stations, through the use of pyranometers, or by satellites. The solar irradiation data are generally not free, and their cost can be high, in particular if high temporal resolution is required, such as hourly data. In this work, we present an alternative method to provide free hourly global solar tilted irradiation data for the whole European territory through a web platform. The method that we have developed generates solar irradiation data from a combination of clear-sky simulations and weather conditions data. The results are publicly available for free through Soweda, a Web interface. To our knowledge, this is the first time that hourly solar irradiance data are made available online, in real-time, and for free, to the public. The accuracy of these data is not suitable for applications that require high data accuracy, but can be very useful for other applications that only require a rough estimate of solar irradiation.

CHP (combined heat and power) retrofit for a large MED-TVC (multiple effect distillation along with thermal vapour compression) desalination plant: high efficiency assessment for different design options under the current legislative EU framework