Design Concepts
Hybrid Desalination Proposal, Dead Sea Water Project
Much study has been done about using Hydrostatic Pressure Reverse Osmosis (HPRO) desalination
for a Dead Sea Water Project. The hydrostatic pressure between the supply reservoir and the Dead
Sea would be used to power this process.
Previous proposals have provided for pumping the water to a higher elevation reservoir so that
there is sufficient pressure for powering the HPRO desalination process, and to provide pumped
storage for hydroelectric peaking power. However, a simple analysis of the processes involved
reveals that it would be much more efficient to utilize electric pumps powered by the gravity
flow hydroelectric project to boost the inflow pressure for the HPRO desalination. This would
save the purchase and maintenance expense of both a pumping station on the intake side of the
project, at the Med Sea, and a storage reservoir at the higher elevation.
The simplicity of my design for gravity flow in a relatively short, large diameter, and below
Med sea level tunnel provides the economic advantage that has elevated the potential of this
particular design above all contending design concepts. In effect, the Med Sea is the only
required reservoir for the hydroelectric peaking power production, and for the HPRO desalination
process. By boosting pressure about twenty percent, the needed pressure for the HPRO desalination
process can be supplied.
Mechanical vapor compression (MVC) desalination combined with high pressure feed water spray in
the evaporation chamber, should be combined with hydraulic pressure reverse osmosis (HPRO)
desalination as a first stage, with the MVP process supplying a second stage. If 45% of the feed
water can be converted to fresh water in the first stage HPRO process, then the size of the MVC
plant can be reduced by almost 50%, perhaps enabling reductions in cost of the complete project.
Blending of the water from the HPRO plant with the pure water from the MVC plant will also be
beneficial, allowing the HPRO plant to operate at double the salt concentration in the
desalinated water, since it can be mixed in almost equal portions with the pure water from the
MVC plant.
The MVC plant will concentrate the brine outflow from the HPRO plant, producing a brine
concentration that is equal to the present density of the Dead Sea Water. This concentrated
brine would be injected at low velocity into the Dead Sea Water, just below the present level
of the Dead Sea. This would prevent mixing with the surface layer of Med sea water, and also
avoid contamination of the brine content of the deep Dead Sea water that supplies the potash
mining operations at the south end of the Dead Sea. This hybrid desalination arrangement would
remove 90% of the feed water as potable water.
Desalination plants located on Jordan’s side of the Dead Sea, taking water from the twenty-five
meter layer of Med sea water to be deposited on the top of the Dead Sea, could use a similar
process of RO desalination powered by electric power from the Dead Sea Water Project’s
hydroelectric capacity. Special rates for this power can be arranged as a concession to Jordan’s
support of the project. The only difference in efficiency of pumped pressure RO desalination
versus hydrostatic pressure RO desalination is the operating efficiency of the pumps, the cost of
maintaining the pumps, and the installed cost of the pumps.
The first stage of the Dead Sea Water Project desalination plan can be for RO desalination; with
plans to add the MVC desalination coming on line at the time the Dead Sea is filled to its
desirable level.
That means that a sea water reverse osmosis plant of about 500,0000,000 cubic meters per year
annual production would be sufficient for the first phase of the Dead Sea Water Project
construction plan, with the necessary MVC capacity to be added within three years after the
beginning of operation of the project.
Jordan could plan their own desalination project according to their needs, saving substantial
transport cost by picking up the water on the east side of the Dead Sea, and operating their own
desalination plants so as to avoid any control by other nations of their water supply. However,
they can arrange for their share of water from the first desalination plant that will be a part
of the Dead Sea Water Project, if they so desire.
There should be a regional agreement to eventually have all desalination plants operating on the
Dead Sea to have an outflow brine concentration equal to the Dead Sea water density. This would
enable the maximum extraction of water from the Dead Sea resource, while causing the least
disturbance to the Dead Sea environment.
The above plan was prepared by me on Feb 22, 2005.
Randolph Gonce
Design Concepts Engineer
Ezekiel’s Water Project
276 Co Rd 56
Stevenson, AL 35772
USA
256 4372687
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