By Steve Minett
A new industrial complex in Saudi Arabia, including desalination and power plants, has been built in Yanbu. The complex needed both cooling water for the power plant and raw water supply for the desalination plant.
It’s no surprise that most of the Arabian Peninsula is arid. It scarcely rains and water from both the sky and underground aquifers is not adequate to supply the needs of the population, agriculture and industry (see Hidell, H.R., “Saudi Arabia—The Heart of the Arab World,” WC&P, April 1998).
With a population of approximately 20 million and depletion of underground water resources, the lack of perennial rivers or permanent water bodies has prompted the development of extensive seawater conversion or desalination facilities. There are now some 30 water-processing stations scattered over the country where desalination plants of various number, size and process are being operated.
What is desalination?
Desalination, also called desalting, is the removal of dissolved salts from seawater and in some cases from the brackish waters of inland seas, highly mineralized groundwater (e.g., geothermal brines) and municipal wastewater. The desalination process renders such otherwise unusable waters fit for human consumption, irrigation, industrial applications, and various other purposes. While membrane efficiencies and costs are improving, existing desalination technology requires a substantial amount of energy and, therefore, is expensive. For this reason, it’s generally used only where sources of fresh water are not economically available.
The desalting of seawater is an ancient notion. Aristotle described an evaporation method used by Greek sailors of 4 B.C. An Arab writer of A.D. 8 produced a treatise on distillation. In the 19th century, the development of steam navigation created a demand for non-corroding water for boilers; the first patent for a desalination process was granted in England in 1869. The same year, the first water distillation plant was built by the British government at Aden, a city in what is now Yemen, to supply ships stopping at the port south of the entrance to the Red Sea. The first large still to provide water for commercial purposes was built in 1930 on the island of Aruba, near Venezuela. The largest desalination project in operation today is in al-Jubayl in Saudi Arabia. That site can produce 1.17 million cubic meters (mcm) of desalted water per day—or 310 million gallons per day (mgd).
For comparison, in the Western Hemisphere, two plants are under construction or scheduled to be built that will be the largest in the Americas—one in Tampa, Fla., at 25 mgd and another even bigger on the Caribbean island of Trinidad at 28.8 mgd.
Today, more than 8 mcm of fresh water were produced each day (2.11 bgd) by several thousand desalination plants throughout the world. The global desalination capacity expanded rapidly during the 1970s and 1980s as the oil-rich countries of the Middle East improved their standards of living. These countries produce about 75 percent of the world’s desalinated water. The United States produces about 10 percent; and Europe and Africa each account for approximately 5 percent.
Dual uses in the desert
In Saudi Arabia, the requirements necessitated a large scale custom pump made from special materials for use in a new industrial complex that will feature a desalination plant as well as a power plant.
The power and desalination plants are located in Yanbu, a city of 30,000 people that serves as the country’s second Red Sea port after Jidda and is the main port for Medina, 100 miles to the east. The economy of Yanbu was traditionally based on the pilgrim trade—which accounts for more than two million Muslim visitors to Mecca a year—and the export of agricultural products, especially dates. Its harbor is being enlarged and improved to ease the pressure on Jidda. It has one terminus of three pipelines built in the 1980s for the delivery of petroleum and petroleum products to a major petrochemical complex. Several new complexes are being planned at Yanbu.
“We’re just starting it up and there are two more they’re going to be adding,” said A-C Pump’s Jim Peterson. “It’s all refineries over there and the power plants to run them.”
Thus, water supply requirements were a major consideration in the design of the two plants. The complex needs both cooling water for the power plant and raw water supply for the desalinization plant. The water is to be divided almost equally for power and industrial water supply.
In the power plant, which is oil powered, the raw seawater is used to cool the turbine generators producing the power. The cooling water is a once-through system, where seawater is pumped through the cooling system and then returned to the sea.
The desalination plant will supply industrial water for the growing industry in the Yanbu region. Yanbu is heavily industrialized with numerous refineries, chemical plants and other general industry. The raw seawater being used for this industrial water supply will be pumped to the desalination plant where the water will be filtered and pumped throughout Yanbu.
The pump used is specifically designed for raw water from the Red Sea, which is a fairly aggressive fluid. Therefore, it has been designed with all nickel-aluminium-bronze (NiAlBrz) materials. The pump is rated at 60,000 cubic meters per hour (m3/hr), or 264,000 gallons per minute (gpm), at 30 meters head pressure—about 97 feet. This pump is technically unique in that these types of pumps are normally supplied with cast components.
“Due to site overhead crane weight handling restrictions,” said Peterson, “it was necessary to limit the maximum weight of any one component of this pump to 40 tons.” The motor itself generates 5,000 horsepower and weighs in at 90,000 pounds, and a single pump totals 140,000 pounds overall—or some 70 tons.
He added, “To meet this requirement, we fabricated the components, which are normally cast out of NiAlBrz plate, which will remove about 20,000 pounds, from the overall unit weight.” Cast units—as opposed to fabricated ones—are heavier, he said. Completely assembled the units will weigh 100 tons and be over 11 meters long.
These pumps will be pumping the raw seawater into a 110-inch pipeline and will be the sole source of cooling to the power plant. “To put the capacity into perspective,” said A-C Pump’s Paul Biver, “we could fill an Olympic-sized swimming pool in less than five minutes with this pump!”
Even in an energy rich country such as Saudi Arabia, energy efficiency is growing in importance. Peterson said the rated pump efficiency is greater than 90 percent, which was several points higher than the other bidders on the project. “This will result in up to $100,000 in energy savings per year,” he added. The pump is powered by a 4,000-kilowatt (kW) motor.
The region of the Middle East will be the proving ground for advances in desalination technology, as the water requirements and thus the need grow exponentially. Like the United States, economic restrictions for these types of projects are minimal and the only setbacks are in the technology itself. With innovations in pump designs similar to the custom pumps made by companies like A-C, advances in this critical field—already starting to assume its position as the world’s most important—will come that much quicker.
The Custom Pump Operation of A-C Pump, a subsidiary of ITT Industries, is located in Pewaukee, Wis.
About the author
Dr. Steve Minett heads Minett Media of Cambridge, England. He holds a bachelor’s degree from the University of Sussex in the United Kingdom and a post-graduate diploma in social science as well as master’s and doctorate degrees from Stockholm University. He writes about a wide variety of water quality and supply issues around the globe. Minett can be reached at +44 1954 230-250, +44 1954 232-019 (fax) or email: [email protected]
The pumps from A-C Pump are specifically designed to pump aggressive, raw water from the Red Sea and are designed with all aluminum-bronze materials. The pumps are rated at 60,000 m3/hr (264,000 gallons per minute) at 30 meters of head.
The “Desalination—The Global Expansion of Advanced Water Technology” Conference, conducted by The Center for Business Intelligence (CBI) of Boston, will be held June 29-30. Organizer of more than 150 conferences, CBI’s business-oriented forums explore the latest investment opportunities and critical issue solutions in the electric, gas, oil and water sectors.
CBI corporate sponsors include Bank of Boston, Andersen Consulting, General Electric Power Systems and water industry leader USFilter Corp. CBI produces the U.S. Water and Waste Water Conferences held in conjunction with the U.S. Conference of Mayors. For more info, call coordinator Chris Laganas at (781) 939-2407.
Water Recycling: Here to there and back again
Finding more uses—including less discriminating palates—for recycled water will be the big mantra of the 21st century, according to Ron Linsky, executive director of the National Water Resources Institute in Fountain Valley, Calif., a position that finds him well-placed in desalination and water reuse circles.
A California project set to unfold over the next year likely will offer the greatest effort to date globally on recycling water, Linsky said.
“One of the big things we’re assessing is the new Groundwater Replenishment Project in Orange County,” he said. “It’s going to be the largest recycling project in the world. It’s already in early stages of conceptual design and will have a 100-million-gallon-per-day potential. That’s the upper end of it.”
Costs at that stage are projected at $300 million to $400 million. It will take secondary effluent, i.e., municipally treated wastewater, and pass it through a microfiltration, reverse osmosis and UV disinfection process to produce extra high quality water to use for groundwater recharge and seawater intrusion prevention. The water can later be retrieved after it has percolated through soils naturally into the aquifer.
“It’s going to be a remarkable project… to provide an opportunity for 2.5 million people in Southern California to be water independent. They won’t have to rely on outside sources of water or transfers from other areas such as aqueducts to bring Colorado River water into the area. After it’s up and running, you’ll probably see this type of program everywhere in the world. ”
The Orange County Water District and sanitation districts, as well as environmental engineering consultants Camp Dresser & McKee, are involved in preliminary work on the project, to cost $4.8 million and focus on providing drinking water for 200,000 families.*
California is under tremendous pressure to reduce its dependence on Colorado River water and develop alternative sources. One example is San Diego’s “Toilet to the Tap” program, which recycled wastewater for potable use—an idea met by public distaste. Linsky said similar programs have failed in Northern California and Florida because a naive public perceives the idea as “unconscionable.” Unfortunate, he said, because the ecological process of water itself involves recycling.
“You and I drink water that’s been through two or three kidneys before we get it, probably even a dinosaur’s kidney at some point,” Linsky said. “If you live in foreign country, you realize that clean water is like gold, regardless of where it comes from.”—Carlos David Mogollón
World’s Largest Seawater Desalination Plants
The following is a list provided by Klaus Wangnick, who compiles the IDA 2000 Desalting Plants Inventory (also known as the Wangnick Report) for the International Desalination Association. Report No. 16 of the biennial publication, which includes detailed data on 14,000 installations, is to be released in early May. For more information, see his website: www.wangnick.de
1. Al Jobail, Saudi Arabia—Total capacity: 1,173,000 m3/d (310 mgd); 46 multi-stage flash distillation (MSF) units + 15 RO units; Suppliers: Mitsubishi (10 MSF), MHI/Sasakura (16 MSF), Hitachi Ziosen (10 MSF), Ishikawajima (10 MSF), Preussag Noell (15 RO, membranes: DuPont)
2. Jebel Ali, United Arab Emirates (Dubai)—Total capacity: 869,000 m3/d (230 mgd); 28
MSF units; Suppliers: Weir Westgarth (14 MSF), Envirogenics (4 MSF), Ansaldo
(3 MSF), Fisia Italimpianti (4 MSF), Hyundai (3 MSF)
3. Taweelah, United Arab Emirates (Abu Dhabi)—Total capacity: 806,000 m3/d (213 mgd); 16 MSF units; Suppliers: Fisia Italimpianti (9 MSF, 6 of them are the largest
single seawater plants with 57,600 m3/d, or 15.2 mgd, each), Sidem (4 MSF), Hanjung (3
4. Doha, Kuwait—Total capacity: 695,000 m3/d (184 mgd); 23 MSF units; Suppliers:
MHI/Sasakura (12 MSF), Fantuzzi Reggiane (4 MSF), Ishikawajima (7 MSF)
5. Az-Zour South, Kuwait—Total capacity: 482,000 m3/d, 16 MSF units;
Suppliers: MHI/Sasakura (12 MSF), Hanjung (4 MSF)
6. Shuaiba, Saudi Arabia—Total capacity: 454,000 m3/d (120 mgd); 10 MSF units;
7. Al Khobar, Saudi Arabia—Total capacity: 450,000 m3/d (119 mgd); 18 MSF units;
Suppliers: Sidem (10 MSF), Hitachi Zosen (8 MSF)
8. Jeddah, Saudi Arabia—Total capacity: 420,000 m3/d (111 mgd); 18 MSF units + 10 RO units; Suppliers: Envirogenics (10 MSF), Weir Westgarth (4 MSF), Sasakura (4
MSF), Mitsubishi (10 RO, membranes: Toyobo)
9. Umm Al Nar, United Arab Emirates (Abu Dhabi)—Total capacity: 400,000
m3/d (106 mgd); 16 MSF units; Suppliers: Sidem (7 MSF), Fisia Italimpianti (3 MSF),
Ishikawajima (6 MSF)
10. Yanbu, Saudi Arabia—Total capacity: 382,000 m3/d (101 mgd); 9 MSF units + 15 RO units; Suppliers: Snam Progetti (4 MSF), Mitsubishi (15 RO, membranes: Toyobo),
MHI/sasakura (5 MSF)
11. Abu Fontas, Qatar—Total capacity: 330,000 m3/d (87.1 mgd); 13 MSF units, suppliers Weir Westgarth (9 MSF), Sumitomo (4 MSF)