White Papers
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The Economics of Downtime A key cost that is seldom estimated during evaluation of various technologies in seawater reverse osmosis (SWRO) projects is the cost of downtime, both planned and unplanned.This paper will prove that these downtime costs are significant to both the investors and the operators of the plant. Therefore plant availability must be a primary factor to be considered in the design phase. Plant availability is even more critical in evaluating the energy recovery technologies as they can cripple production if they break down often and require high maintenance.  Download PDF
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The Availability Advantage of Reliable Energy Recovery Technologies Availability can be defined as the probability that a system or piece of equipment when used under the specified conditions operates satisfactorily at any given time. The availability of the equipment installed in a seawater reverse osmosis facility (SWRO) is extremely important to the price, quality and quantity of the final product – water. There are three critical components in the SWRO processes; the main high-pressure feed pumps, the RO membranes, and the energy recovery device (ERD) system. This paper focuses on the economic benefits and importance of the availability of energy recovery devices in SWRO desalination plants. Download PDF
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Lifetime Durability of Ceramic PX Energy Recovery Devices In order to ensure the long-term and trouble-free lifetime of the seawater reverse osmosis (SWRO) process and its enabling technology, it is essential to utilize the most advanced and reliable materials of construction. One of the more advanced and unique materials currently in use in SWRO desalination applications is high purity (>99%) aluminum oxide (alumina) ceramics. Due to its hardness, self-lubricating properties, high compressive strength and chemical resistance, alumina ceramics create an ideal fluid bearing for the rigors of seawater applications, which perform in conditions that combine corrosive and potentially two-phase (solid/fluid) environments. Download PDF
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Highly Efficient Energy Recovery Devices Energy Recovery Devices (ERDs) are at the core of saving energy in the operation of any seawater reverse osmosis (SWRO) desalination facility. Isobaric or “positive displacement” devices such as the ERI PX Pressure Exchanger™ (PX™) devices are the most efficient solution available today and can reduce the energy consumption of seawater reverse osmosis (SWRO) systems by up to 60 percent. This paper will examine and quantify the efficiency of ERI PX devices based on an extensive database of actual test results. Significant historical performance data was evaluated and analysed to validate efficiency figures and guarantee increased efficiencies for several PX device models, including the PX Pressure Exchanger models PX-220, PX-260 and PX-300 units, The existing models offer 96.8% efficiency guarantees, which in turn offers significant energy savings for plant owners and operators. Test data will also quantify the efficiency gains provided by ERI’s Quadribaric™ technology. Download PDF
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A Five Year Lifecycle Analysis of the Perth Seawater Desalination Plant Facing impending water shortages in April 2005, Western Australia's Water Corporation formed a public-private partnership with global water treatment company Degrémont and constructor Multiplex. The resulting Multiplex Degrémont Joint Venture (MDJV) was tasked with design, build and commission of Perth's first large seawater desalination plant in just 18 months. In November 2006, the 144,000 m3 /day (38 million U.S. gallons per day) seawater reverse osmosis (SWRO) plant began delivering desalinated water into Perth’s municipal water supply. At the time of commissioning, the Perth Seawater Desalination Plant (PSDP) was the largest SWRO plant operating in the southern hemisphere and the largest single source of water for the city of Perth, supplying approximately 17% of the city’s needs. This paper will demonstrate how sustained long-term energy efficiency can be achieved in large-scale SWRO plants. Performance of the energy recovery system during commissioning of the PSDP will be compared to performance measured onsite nearly five years later. The importance of proper system design and operation for achieving maximum performance and longevity will be addressed. In addition, the role of advanced materials in sustaining performance over the designed life of the plant will be considered. Download PDF
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A Case Study: Energy Use and Process Design Considerations for Four Desalination Plants in California California is the 7th largest economy in the world with a significant need for drinking water and irrigation water for agriculture to keep up with the state’s current needs and future demands. As part of this need, California has funded projects related to more than 10 proposed desalination plants across the state through Proposition 50, a grant program administered by the State Department of Water Resources. The Sand City Desalination Facility, located in Monterey County, California, is the first full-scale, municipal desalination plant in California permitted under the new surface water treatment regulations. The facility has a capacity of 2.3 million liters per day (MLD) and produces approximately 1.1 MLD on average. Additionally, design features led to nearly $100,000 in rebates for energy efficiency measures expected to save more than 1.2 million kilowatt-hours of electricity and 667 tons of greenhouse gas emissions per year. The Cambria Desalination Facility was on track to be the second full-scale, municipal desalination plant in California. However, permitting issues related to intake location and selection has delayed the project. The proposed facility will produce up to 3.8 MLD. The proposed scwd2 Desalination Facility in Santa Cruz will produce up to 9.5 MLD and is currently in the preliminary design and permitting phase. Several in-depth studies have been completed to identify and demonstrate solutions to address concerns from the public and regulators. Download PDF
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SWRO Energy Recovery Devices: Pushing the Envelope of Materials Capabilities Energy recovery devices (ERD) have played a key role in enabling cost effective seawater desalination. Ironically, increasing efficiency and reliability requirements for large water factories are now pushing energy recovery devices to the next level of performance. Expectations are ever increasing in terms of reliability, efficiency, availability, and lower operational costs. Simply put, expectations are high and units must operate trouble free in one of the most corrosive and inhospitable industrial environments known. Energy recovery efficiency is still paramount; however reliability, serviceability, customer support, and system availability are becoming all equally important to our customers. Download PDF
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New Concept of Upgrade Energy Recovery Systems Within An Operating Desalination Plant. The Palmachim Desalination plant is one of the largest seawater reverse osmosis (SWRO) desalination plants in Israel with a capacity of 120,000 cubic meters per day. Built by the Via Maris Desalination Ltd. consortium, the plant consists of six (6) parallel SWRO trains, each with a permeate production capacity of up to 20,000 cubic meters per day. In addition its high-capacity SWRO trains, the Palmachim plant is unique because it was designed to be easily turned on, off or slowed down. Electricity tariffs in Israel are significantly higher during the day than at night with a cost ratio of up to six to one. The plant’s flexibility allows the operators to minimize energy consumption during the day when the power cost is high by shutting down up to 85% of the plants capacity. Download PDF
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Brackish Water Desalination: Energy and Cost Considerations Energy recovery devices are employed in nearly all seawater reverse osmosis (SWRO) desalination plants to recover pressure from the membrane reject stream and return it to the process. Because of the high pressures and low membrane permeate recovery rates common in these systems, the membrane reject stream contains a considerable amount of energy. The use of energy recovery devices in seawater RO is readily justified on the basis of operating cost savings. However, the application of energy recovery is much less common in brackish water RO systems, primarily because of the relatively low feed pressure and low flow rate of the membrane reject stream. The fear is that energy recovery devices can also potentially limit the flexibility of a brackish RO process because of efficiency losses or flow-rate constraints encountered during off-peak operation. Download PDF
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Desalination and Energy Efficiency for a Uranium Mine in Namibia The authors present energy saving solutions for desalination water supply for mining applications. Detailed design data for the Uranium mining desalination plant are given. Environment and economic conscious owners and operators will learn methods of design and operation of desalination systems in mining, which can be easily extrapolated to many other industrial needs, and how to minimize the total cost of ownership of a desalination process. Download PDF
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