Genesis Morocco


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Genesis Morocco

Project Genesis is a strategic sustainable development framework for Morocco to translate from being a net importer of energy and a country facing water shortage issues, into the number one producer both of clean renewable energy and water in the region.

Sunday, June 11, 2006    <<Home

Project Atlas

Ashkelon Desalination Plant, Seawater Reverse Osmosis (SWRO) Plant, Israel.



The new Ashkelon seawater reverse osmosis (SWRO) plant - the largest desalination plant of its kind in the world - commenced initial production in August 2005, less than 30 months after construction began. Initially running at around 30% to 40% capacity, it will ultimately provide an annual 100 million m³ of water, roughly 5% to 6% of Israel's total water needs or around 15% of the country's domestic consumer demand.

Built by VID, a special purpose joint-venture company of IDE Technologies, Vivendi Water and Dankner-Ellern Infrastructure, the plant design includes membrane desalination units and facilities for seawater pumping, brine removal, raw water pre-treatment and product water treatment. In addition, the project also required the construction of workshop and laboratory buildings, access roads and a dedicated gas turbine power station.



In total, the project cost approximately $250 million and was funded by a mixture of equity (24%) and debt (77%). The overall revenue over the period of the contract will be in the region of $825 million.
BACKGROUND

North Africa and the Middle East holds more than 6% of the global population, but less than 2% of the world's renewable fresh water. In common with other countries in this, the planet's most water-scarce region, Israel has chronic problems over water resources. Setting out to address them, in 2000, Israel launched a Desalination Master Plan.

This strategy called for the construction of a series of plants along the Mediterranean coast, to enable an annual total of 400 million m³ of desalinated water to be produced by 2005, chiefly for urban consumption. According to the plan, production is intended to rise to 750 million m³ by 2020.

The Ashkelon facility operating at full capacity will itself contribute 25% of the initial target set out in the Israeli government's master plan.



PLANT DESIGN

Reliability and continuity of operation have been heavily prioritised throughout the design process. Providing twice the capacity first envisaged, the facility forms two almost entirely self-contained plants, each operating autonomously to provide 50 million m³/yr of desalinated water.

With the exception of the seawater intake, the product water treatment system and the dedicated power plant, the site sub-systems have been duplicated to ensure independence of operation. In addition, those elements which are shared have been designed with the sufficient in-built back-up capacity to allow separate service to each plant.

The use of advanced SWRO technology and state-of-the-art energy recovery systems to reduce operating costs has achieved one of the lowest water prices - $0.527/m³ - ever offered for this kind of operation.

The plant occupies 75,000m² of industrial site belonging to the Eilat-Ashkelon Pipeline Corporation (EAPC), some 700m north of an existing Israel Electrical Company power station. Using the power station's cooling seawater discharge was one of a number of intake options initially considered but ultimately rejected in favour of using an open, submerged type, principally due to site constraints and hydrogeological limitations.

The system comprises three parallel pipes, a configuration designed to safeguard supply and enhance operational reliability by producing non-turbulent feed water flows. High density plastic piping - simple to clean and relatively resistant to biological growth - has been used to minimises maintenance.

The intake pumping station itself is equipped with vertical pumps, based on their long track-record of success in similar applications and their high degree of flexibility in operation. From the pumping station, raw seawater flows to the pre-treatment facilities through two separate lines. This ensures that the plant can at least continue to operate at half-capacity in the event of blockage or failure in one of the pipelines or static mixers. The dosing pumps at the chemical treatment facility are each equipped with real-time flow-rate adjustment and adequate redundant capacity has again been factored in to guard against down-time.

Filtration is performed in two stages, starting with gravity filters containing gravel, quartz sand and anthracite media. The combination of long residence time and a distribution system designed to minimise clogging and preferential channel formation contribute to achieving high filtration efficiency. The filters, which have an automatic backwash facility, offer a 33% standby overcapacity and were pilot tested to ensure their ability to cope with storm turbidity levels. A series of cartridge filters form the second stage, arranged in two parallel batteries. They share many of the previous design features to maximise efficiency and have a built-in spare capacity of 40%.

The filtered water passes to the SWRO process via high pressure pumps, equipped with state-of-the-art Double Work Exchanger Energy Recovery (DWEER) devices which can be operated independently of each other. This approach increases both the flexibility of the system and its overall efficiency.

The desalination facility consists of 32 Reverse Osmosis (RO) treatment trains, built over four floors and containing 40,000 membrane elements, which use optimised, multi-stage RO and boron removal procedures.

Achieving a high boron ion reduction was an important design consideration. Accordingly, the method selected is highly flexible and readily adjustable to feed water temperature fluctuations, being capable of delivering a removal efficiency of more than 92% when necessary. These demands, coupled with a number of other key requirements, including high pH tolerance, continuous low pressure operation, low membrane fouling and cost-effective, reliable performance, led to FilmTec elements being selected for the RO operation.

While the final water quality in terms of boron levels is achieved during the multiple RO stages, post treatment with lime will be used to re-mineralise the product water, which will then enter the national water system.

In keeping with the project's general drive to ensure reliability and continuity of operation, while also working to a low water sale price, electricity is provided from two separate sources. A dedicated gas turbine power station, fuelled by natural gas, has been built adjacent to the desalination plant, while an overhead line provides supply from the Israeli national grid. The provision of a dedicated power plant is a major factor in both safeguarding operational reliability and reducing energy costs, as it is offers protection from daily or seasonal demand fluctuations. The desalination system is expected to run at a continuous base load for most of its operation.

LEAD CONTRACTORS AND SUPPLIERS

The contract was formally awarded by the Israeli Ministries of National Infrastructure and Finance, on behalf of the Government of Israel. VID, the special-purpose JVC, comprises IDE Technologies (50% and lead partner), Vivendi Water (25%) and Dankner-Ellern Infrastructure (25%).

The Engineer, Procure, Construct (EPC) contractor was OTID, a joint venture company formed by IDE and OTV (Vivendi Group). Israel Chemicals and Delek Group are equal-share partners in IDE Technologies. Operation and maintenance is the responsibility of a Vivendi Group, IDE and Ellern joint venture.

The reverse osmosis membrane elements were provided by the Dow Chemical Company and the temperature and pressure transmitters by Smar. Mekorot distributes the product water.