A desalination plant by Doosan. Photo: Doosan

The United Arab Emirates is a country characterized by scant natural freshwater resources and, at the same time, world-leading efforts to meet its water needs by seawater desalination. The latest addition to an extensive desalination program in the country is the Shuweihat 2 independent water and power project.

Shuweihat 2, S2 for short, got under way in July 2008 when the project was awarded to desalination and power contractors. The desalination component went to Doosan Heavy Industries & Construction of Korea, self-described as the Number One desalination facilities manufacturer in the world.

The contract-winning desalination process configuration relies on duplex stainless steel, for the first time in Doosan’s history. With this project, Doosan is the last major desalination technology provider to switch to duplex in the crucial process component, the evaporator chamber, as well as in associated piping.

Doosan selected Outokumpu as the supplier of the largest single share of the total duplex need for S2. Doosan also adopted Outokumpu’s duplex concept for desalination. This concept involves the use of two or three different grades of duplex according to their corrosion resistance properties and the corrosiveness of the process environments.

Doosan’s historic switch came as a result of untiring efforts by the Outokumpu desalination and sales team to convince the technology provider of the benefits of duplex.

The chief benefit is the high strength of duplex. This allows a considerable reduction in material compared to conventional alternatives, either carbon steel (in various concepts) or austenitic stainless steel, without compromising performance. The thinner material gauges enabled by duplex mean larger units with the same amount of material, which translates into larger capacities – a key determining factor among competing desalination methods. Importantly, switching to duplex requires no adjustments to the evaporator design.

According to Outokumpu’s multiple-duplex concept, S2 will employ duplex 2205 in the bottom section of the evaporator chamber, where corrosion is severe, and lean duplex LDX 2101® in the upper section, while duplex 2304 is used in piping.

Doosan’s choice of materials for S2 proves the success of Outokumpu’s pioneering campaign to champion duplex stainless steel in desalination. “This deal confirms conclusively our duplex concept,” says Hachemi Loucif, Outokumpu’s desalination segment leader. He stewarded the Doosan-Outokumpu deal, and his Korean colleague Seung-Hoon Jee played the crucial role locally.

“Now there is no return to carbon steel or conventional austenitics in desalination evaporator chambers,” Mr. Loucif continues. He points out that while there are a number of economic benefits from duplex, there are also environmental benefits which arise from the possibility of using thinner gauges, including savings in production, transportation and welding.

Project
Shuweihat 2 (S2) power generation and desalination project, developed as an Independent Water & Power Project. Located in Jebel Dhana in Shuweihat, UAE. Scheduled for completion in August 2011.

Owner
JV of Abu Dhabi Water and Electricity Authority of the UAE (60%) and GDF Suez of France (40%)

Capacity
100 million g/d of desalinated water; 1,500 MW of power

Contractors
Desalination: Doosan Heavy Industries & Construction Co., Ltd. of Korea
Power: Samsung Engineering & Construction Group of Korea

Desalination technology
Multi-Stage Flash (MSF)

Outokumpu supply
1,832 tons of duplex stainless steel plate, out of the total duplex need for the project of approx. 5,800 tons. In duplex grades LDX 2101® (1.4162), 2304 (1.4362) and 2205 (1.4462) for the Outokumpu “triple duplex concept” (using three grades of duplex to optimize grade selection against process conditions).

Contact:
Hachemi Loucif
Head of Desalination Business
Outokumpu Group Sales & Marketing
Phone +46 586 47 626
Email hachemi.loucif(at)outokumpu.com