More power to desalination

Published: November 1, 2012
  • Marafiq power and desalination plant – photo GDF SUEZ/ABACAPRESS/ALSAGAFF HELMY
  • Marafiq power and desalination plant – photo GDF SUEZ/ABACAPRESS/ALSAGAFF HELMY
  • Marafiq power and desalination plant during construction (October 2009) - photo GDF SUEZ/ABACAPRESS/ALSAGAFF HELMY
  • Tractebel Engineering team on Marafiq site (2009) – photo Tractebel Engineering
  • Men at work on Marafiq site (2008) - photo GDF SUEZ/ABACAPRESS/ALSAGAFF HELMY
  • Taweelah A1 power and desalination plant-MED units – photo Tractebel Engineering
  • Extension of Taweelah A10-2 x 214 MW/750 t/h (2009) – photo Tractebel Engineering
  • Al Dur power and desalination plant –RO filters – photo Patrick Joie (Tractebel Engineering)
  • Patrick Joie on Al Dur site (2007) – photo Tractebel Engineering
  • Barka 2 power and desalination plant (April 2009) – photo Tractebel Engineering

 

In developing arid regions, water is often in as much demand as energy – calling for solutions that better meet both needs in one. With a decade’s experience in Power & Desalination plants in the Middle East, Tractebel Engineering knows first-hand what is involved…

THE MIDDLE EAST DESALINATION BOOM

Spectacular development in the Middle East in recent decades has seen entire urban and industrial hubs develop on the Arabian coastlines – with direct consequences. Read more about the Middle East desalination boom

EXPERTISE IN DEVELOPMENT

Independent Water & Power Producers (IWPP) are key to the development of Power & Desalination plants in the Middle East for good reason. But competition between consortia wanting to secure the investment opportunities is fierce. Ultimately the ability to configure the plant in a way that delivers the best possible tariffs wins the day. Find out more about our expertise in development

A FINE RESULT – MARAFIQ C’EST MAGNIFIQUE

The world’s second largest Power & Desalination plant, Marafiq in Saudi Arabia was realised in just 35 months and visited by royalty, not once but twice! Read more about this magnificent project

3 MAIN DESALINATION OPTIONS

Need a reminder of the main desalination processes?

  • Multi-Stage Flash Distillation (MSF)
  • Multiple-Effect Distillation (MED)
  • Reverse Osmosis (RO)

THE MIDDLE EAST DESALINATION BOOM

Spectacular development in the Middle East in recent decades has seen entire urban and industrial hubs develop on the Arabian coastlines – with direct consequences. Demand for electricity has spiraled, as has the need for fresh water – resulting in massive thermal power plant developments coupled with state-of-the-art desalination plants.

A CLEAR AND ONGOING NEED

The Middle East is one of the world’s driest regions. Yet, its modern coastal cities continue to attract more and more people and industries. These industries (including Petro Chemical Plants), operating in extreme temperatures, use vast amounts of cooling water. As saltwater cooling requires higher CAPEX (stainless steel materials), fresh water cooling is preferred. Predictions are that by 2025 fresh water consumption in general will increase to roughly 10 times what it was in 2006. Indicating that, even following the first desalination plant boom (since 2000) which meets today’s needs, realistically, more is to come.

POWER – THE DECIDING FACTOR

The issue is, to provide desalination plants of the scale required, the most cost effective solution is to couple them with thermal power plants functioning in co-generation mode – providing better efficiency and use of the heat generated to vaporise and distil the seawater. Fortunately, what the Middle East lacks in fresh water supplies it makes up for with its oil and gas resources. The region’s ability to fuel and consume a high base load of electricity (besides the growing industrial sector, booming real-estate developments demand modern electrical appliances and year-round air-conditioning) is relatively constant – making investment in Power & Desalination plants all the more attractive.


EXPERTISE IN DEVELOPMENT

Independent Water & Power Producers (IWPP) are key to the development of Power & Desalination plants in the Middle East for good reason. But competition between consortia wanting to secure the investment opportunities is fierce. Ultimately the ability to configure the plant in a way that delivers the best possible tariffs wins the day.

THE ROLE AND VALUE OF IWPP

The trend in the Middle East region is for State Authorities to outsource the investment in and operation of large Power & Desalination plants to experienced IWPPs for a set period (usually 20 – 25 years). In return they guarantee to buy all the power and water produced. EPC contractors also generally prefer to bid on projects financed by IWPP as they can be sure that the contracts offer margins that reflect the risk and that financial interest in certifying the completion of the plant will be demonstrated. All round it creates a highly motivating environment, hinged on – the proposal.

EXPERT PROPOSAL DEVELOPMENT

Drawing on extensive thermal PP development experience and in-house, multi-disciplinary expertise to ensure the synergy between technologies, Tractebel Engineering’s talent is determining the right plant configuration:- Identifying the number of gas turbines, type of steam turbines, desalination process, the number of units, the re-mineralisation process, while considering the net power generated, fuel consumption, water produced, plant availability, CAPEX and OPEX. We have successfully assisted IWPP in the development phase of many of these plants in this way – each one different in terms of capacity, location and footprint, the quality and intensity of the feed water, the options for concentrate disposal… There are always multiple configuration options, but just one goal –to deliver so many MW and MIGD (million imperial gallons/day) at the best price.

View our history in power & desalination development

 

 


A FINE RESULT – MARAFIQ C’EST MAGNIFIQUE

The world’s second largest Power & Desalination plants, Marafiq in Saudi Arabia was realised in just 35 months and visited by royalty, not once, but twice! As Owner’s Engineer, Tractebel Engineering still looks back at Marafiq as the benchmark for plants of this kind.

MARAFIQ – FAST TRACK FACTS

Begun in June 2007 and fully commercially operational in 2010, Marafiq IWPP is a joint venture between Marafiq, Saudi Electricity Company (SEC), the State Public Investment Fund and an international consortium comprising GDF SUEZ (20%), Gulf Investment Corporation of Kuwait and ACWA Power Projects of Saudi Arabia.

Built within Jubail Industrial City, all power is delivered to Saudi Electric Company (SEC). 37.5% of the water production is consumed by Jubail industrial customers, with the balance distributed to other parts of the province for mixed domestic /industrial consumption. Plant operation is managed by Jubail Water and Power Company (JWAP).

UNIQUE IN SIZE

Even in Saudi Arabia where everything is big, Marafiq; with a capacity of 2,750 MW electricity (CCGT) and 800,000 m3/d desalinated water, is impressive:

  • A site 830 m long by 650 m wide
  • Power block and Desalination unit developed simultaneously:
    12 gas turbines (a 600 m long turbine hall)
    12 heat recovery steam generators
    4 steam turbines
    12 stacks in a row
    27 Multi-Effect Distillers (MED) desalination units
  • Over 9,200 workers on site at peak
  • The desalinated water output will satisfy the daily needs of 4 million people.
  • The power capacity represents close to 10% of Saudi Arabia’s installed capacity.
  • The project was inaugurated by the King Abdullah of Saudi Arabia and visited by HRH Crown Prince Philippe of Belgium as part of an economic mission to Saudi Arabia.

A GOOD INTERNATIONAL TEAM EFFORT

Key to realising the Marafiq project was good planning and a well integrated, multi-disciplinary and culturally aware OE team of 35 people drawn from Tractebel Engineering entities around the world including Belgium, India and Poland.

“We were proud to be the Owner’s Engineer for the second largest power and desalination project in the world. With our multi-cultural team we overcame all the challenges in the realisation of a project that is key for the development of Saudi Arabia.” Jacques Hoffait, Product Director Thermal Power Generation & Desalination.


3 MAIN DESALINATION OPTIONS

Tractebel Engineering can advise its clients on the choice of the 3 desalination techniques:

  • Multi-Stage Flash (MSF) the most common thermal desalination technology today MSF uses steam from a thermal power plant to heat seawater to its flash (boiling) point and condenses the resulting steam to produce distilled water. Any seawater (brine) not vaporised in the first stage is pumped into a second stage tank at a lower pressure corresponding to the lowered temperature of the brine so that it flashes again – releasing more steam and condensate. The “vacuum distillation” process repeats through several stages until the brine becomes too concentrated and drops to a temperature where it can no longer flash.
  • Multi-Effect Distillation (MED) more recently developed; there are fewer suppliers of MED technology which is valued for its lower electrical consumption (less pumping). In principle it is similar to MSF. Desalination takes place over a number of stages “effects” in which the seawater is sprayed onto a layer of horizontal tubes heated, initially by steam from a thermal power plant. Coming into contact with the hot tubes some of the seawater evaporates. This steam is fed into the tubes of the next “effect” – and the process repeats using the steam produced each time to heat the tubes in the following stage before it cools down to produce the desired distilled condensate.
  • Reverse Osmosis (RO) is a non-thermal, filtration process where seawater is forced (using a pressure in excess of the osmotic pressure) through a semi-permeable membrane that removes the salt and other minerals allowing fresh water to emerge on the low pressure side of the membrane. Generally RO is installed on “clean” deep water and rocky shorelines as opposed to shallow, sandy coasts where the seawater contains more particles and ions. Even so, with more effective membranes being supplied today, RO can be considered in the Arabian Gulf provided very efficient pre- treatment (filtration) is foreseen. A trend for hybrid configurations is emerging where RO permeate is mixed with the distillate from thermal desalination to produce the end water product. Drawbacks remain associated with RO’s high energy consumption, delicate operation and use of a lot of chemicals.

WHY DESALINATE?

Globally only 3% of water is “fresh” and not all of that is usable. For countries able to produce power, but unable to rely on natural water supplies, desalination is a reliable solution.

A FUTURE CONCEPT

Reverse Osmosis desalination is found in many countries, particularly those like Spain where coastline space is limited and small RO plants, drawing operating energy from the grid, are most feasible. As a solution to high energy consumption and emission reduction, the viability of connecting RO plants to Off/On Shore Wind or Solar Power sources is now being investigated. As Renewable Energy experts we say “watch this space!”

DUBAI PRESENCE

Tractebel Engineering opened offices in Dubai in 2008 to be closer and more reactive to customers in North Africa and the Middle East.

More information

Jacques Hoffait, Product Director – Thermal Power Generation & Desalination
Patrick Joie
, Chief Engineer (Power & Gas)
Patrick Bruggemans
, Product Manager – OE Projects Thermal Power Generation & Desalination

 

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