Al-Jubail Phase II MSF plant, Saudi Arabia
OJ Morin, who was lead desalination consultant on this project, recalls:
The Kingdom of Saudi Arabia was eager to expand the desalination capacity at al-Jubail in the eastern region of the country. The plant capacity was to be 908,500m3/d. A large power plant was to be built in conjunction with the desal facility. The water and power supplies from the plant (and Phase I) were to be used to support the planned industrial complexes to be built in the area.
This project scored a number of records, including the following:
- Largest desalination plant capacity ever built
- Largest number of units ever sited at one station
- Two-temperature operation
- Use of new scale control additives for the make-up supply
- Lowest dissolved oxygen in the make-up water ever attained at the time
- All copper-nickel tube material for the evaporator condensers
- Use of Reinforced Thermosetting material (RTR or FRP) for all the sea water supply piping, which has a diameter of up to 120 inches.
When preparing the specifications, I called for 2-temperature operation. SWCC wanted the design to be done for 90ºC, but I thought 112ºC would give the plant an additional 20% of capacity for the same plant, thus lowering their operating costs. I also suggested that the individual unit plant capacity be made at 75,700m3/d. This put SWCC into a tizzy, since they had never built a plant larger than 22,700m3/d, or one at an operating temperature higher than 90ºC. They told me that they would have to discuss this internally. They asked why we should require this higher operating temperature and if it was actually possible. I explained that the benefit was an additional 20% capacity from the same plant. A couple of weeks later they told me that they were considering the two-temperature operation, but the plant size could be no larger than 23,600m3/d. Therefore that required 40 evaporators to be built to meet the desired plant capacity.
Just one of the 40 MSF units, each of 22,712m3/d capacity, installed in al-Jubail phase 2 to OJ Morin's specification. – Kurt Kiefer.They further told me that they wanted all design information – release rates, corrosion rates, heat transfer coefficients, etc. – put into the specification. I explained that we had been asked to write a performance specification, in which none of the detailed design information is included. In fact, the contractors were bound to guarantee the performance of the plant, so they should use their own design information. SWCC turned this idea down and required the detailed information to be included, so it was.
To determine if the two-temperature operation should be allowed, SWCC canvassed the manufacturers at a bid meeting. The question they asked the bidders was 'How much more distillate capacity can be realized if the operating temperature is raised to 112ºC?'. As I remember, the responses ranged from 0 to 18%.
Following the meeting the then Governor of SWCC read me the riot act. He wanted to know how I could ask for this amount of water when nobody could deliver it. I told him that the bidders have to guarantee this figure, so if they could influence SWCC to specify a lower amount, they would. I’m not sure he believed me entirely, but the requirement was left in the specification.
With one exception, all bidders guaranteed 20% additional capacity. During the bid negotiations, they did raise their value to one per cent. They continued to insist that this simply could not be done.
The final list of desal contractors chosen by SWCC, with the number of plants to be built, was:
- Sasakura – 20 units
- Westinghouse Hitachi Zosen – 10 units
- Isikawajima Heavy Industries – 10 units
All 40 evaporators passed their performance tests, including the extra capacity.
To date all 40 evaporators are still in service. Corrosion has been minimal and the RTR piping has not given any problems.