sustainable development of water desalination

8/4/2019 Sustainable Development of Water Desalination

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Sustainable Development of Water Desalination – A Middle East perspective

Prepared by: Manish Golwalkar (AS10004)

Background

The complexity expressed through the definition of sustainability notion and its application is a triple

vision: preservation of energy resources and protection of environment, achievement of social values

and justice within the present and for future generations, as well as sustainable economic development.

This paper tries to examine “water desalination” and its effect on the environment, energy systems and

long term sustainability. The focus of this topic centers on the Middle East countries (GCC countries)

which face extreme water scarcity and have adopted water desalination technologies.

Desalination – The definition

In simple terms desalination is the process of removing some salt contents from water so as to make it

suitable for human consumption and agriculture. Specifically, the term desalination is more commonly

referred to conversion of sea water to potable water

Desalination – A quick Economic Perspective

Though sea water desalination sounds like the ultimate solution for perpetual and abundant supply of

potable water for the whole world, the process is fairly complex, very high energy consuming and in

most cases economically unviable due to large investments in the infrastructure for desalination

technologies.



Desalination – The Technology

There are multiple technologies available today to achieve the desalination of sea water. A number of

countries and private companies are developing more and more methods for this process with the

primary aim to minimize the energy requirements for the process. Some of the most common methods

are described below –

1. Vacuum Distillation

Distillation is possibly the oldest known method to remove salts and

other soluble contents of water and is practiced widely in chemistry

labs. Vacuum Distillation is the method where the boiling of water is

achieved at a less than atmospheric pressure and thus a much lower

temperature than normal. This is because the boiling of a liquid occurs

when the vapor pressure equals the ambient pressure and vapor

pressure increases with temperature. Thus, because of the reduced

temperature, energy is saved.

Vacuum distillation is still one of the most preferred methods of desalination due to relatively simpler

process technology and less frivolous energy requirements.

2. Reverse Osmosis

In reverse osmosis, high pressure salt water is

forced through a water-permeable membrane.

Normally water would flow through the membrane

to balance the concentrations, but because of the

high pressure on the salt water side, the process is

reversed. The product water is at approximately

atmospheric pressure, while the salt water is at apressure of anywhere between 15 and 75

atmospheres.



The major energy requirements in this form of desalination are in the pressurization of the salt water.

Reverse osmosis requires the least amount of energy of the desalination processes, requiring 4-6 kWh

per cubic meter.

3. Multi-Stage Flash

In multi-stage flash distillation, the salt

water is heated and then placed in a

lower pressure vessel, which causes a

portion of the salt water to instantly

vaporize (flash). This steam is then

collected and condensed as desalinated

water. As only a portion of the water is

vaporized, the remaining brine goes

through a series of stages at lower and lower pressure, causing more water to be vaporized.

The major energy requirements in multi-stage flash are in heating of the salt water and controlling the

pressure of vessels. The typical energy costs are in the range of 23-27 kWh per cubic meter.

Nuclear Desalination

Nuclear Desalinations is not a method different from the above three methods. Each of the above

methods requires energy to carry out various steps of the process. In general, two types of energy

sources are commonly used – the fossil fuel based and the nuclear energy based. Whereas the principle

method is one of the above three, the source of energy can vary and when it is nuclear energy, the

desalination process is sometimes referred to as Nuclear Distillation.



Water Desalination – Considerations and driving factors

There are a number of reasons for considering desalination of sea water as the dependable source for

potable water despite the energy requirements and impact on the environment –

1. In some countries there is no natural source of potable water. Some of these countries fall in the

total desert zones where rainfall is scares and no other source of water is available.

2. Some of the countries were dependent on their neighbors for supply of potable water. The costs

of such procurements are high and in most cases, such dependence is considered very risky

from sustainability and political points of view.

3. Population growth in water scares areas – higher demand for water

4. Over exploitation of natural resources by agricultural users

5. Failure of current water resources

6. Lack of alternatives to desalination.

The Middle East countries (The GCC countries) in specific have their inclination towards desalination

primarily due the first two points – scarcity and dependence on neighboring countries. However, a

bigger reason for early adoption and expansion of their capacities is the abundant availability of crude

oil. The fossil fuels are not only the intake source of energy for these desalination plants but also the

source of money to source the technology from matured countries.

Desalination –

Impact on the environment

The sea water desalination may appear like a panacea for potable water problems, the associated

environment hazards are aplenty. Some of the impact of desalination is discussed below –

1. Impact of the marine habitats: The effluent in the waste is a heavily concentrated brine solution.

Desalination plants produce liquid wastes that may contain all or some of the following constituents:

high salt concentrations,

chemicals used during de-fouling of plant equipment and

Pre-treatment, and Toxic metals (which are most likely to be present if the discharge water was

in contact with metallic materials used in construction of the plant facilities).

After the brine solution is discharged, it has the potential to kill marine organisms. Although the brine

solution contains natural ingredients of the seawater it may cause damage by its unnatural

concentration to marine population near the outlet. Another concern is the Chemicals from pre-

treatments and from membrane periodical cleaning can harm the habitat. One example is the use of



biocides such as chlorine, which is used to clean pipes or to pretreat the water. These chemicals must be

treated before they are released to the ocean.

2. Impact of rising water Temperature: The discharged waste has the potential to raise the temperature

of coastal waters near the outlet. This has adverse effect on marine life and water quality.

3. The impact of the utilization of land is by destination the seashore for industrial zone instead of using

it for recreation and tourism.

4. The impact to aquifer occurs mainly when there are long pipes conducting seawater and brine. In this

case there is danger of leakage and penetration of salty water to aquifer.

Besides the direct impacts summarized above, there is a pressing concern for

The greenhouse gases produced during the process by the fossil fuels used in the process or The environmental threats from nuclear sources of energy for desalination process. The recent

disaster at Fukushima Daiichi, Japan has further highlighted the dangers of nuclear energy.

Desalination – Global Markets and Middle East Countries

There are two seawater desalination markets:

The GCC countries (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, UAE): mature, oil price driven,

thermal, no political resistance

The rest of the world (China, Spain, Australia, Algeria, India, Japan, US etc.): emerging, scarcity

driven, membrane, projects don’t happen, political resistance needs overcoming.



The following chart shows the cumulative Desalination capacities in the above two markets -

The following chart shows the global desalination capacities -



The Following chart shows the market forecasts for the GCC countries -

The following chart shows the desalination market growth projected for the ROW (Rest of the

World) countries



Conclusion & Take Away

Is desalination the best option?

Food & Water Watch advocates instead for better fresh water management practices. "Oceandesalination hides the growing water supply problem instead of focusing on water management and

lowering water usage," the group reports, citing a recent study which found that California can meet its

water needs for the next 30 years by implementing cost-effective urban water conservation.

Desalination is "an expensive, speculative supply option that will drain resources away from more

practical solutions," the group says

Can Middle East rely on alternate sources of potable water?

The answer to this question lies in the socio-economic and political environments prevailing in the world

today. Whereas environmentalist claim that earth still has adequate natural resources to fulfill the

global needs for potable water, the political compulsions will continue to force human beings to adopt

more environment unfriendly methods like the desalination.

The GCC countries on one side have upper hand in the global politics and economy due to the crude oil,

however, this equation will not last long. The reasons are as follows –

1. The oil reserves are limited and will run out some day.

2. US have large untapped oil reserves that are kept for future. As soon as GCC countries’ oil supply

starts falling, US will start having a bigger control over the oil markets.

Most of these countries do not have adequate supply of natural potable water. Therefore they will, in

one way or the other, depend on other countries for it. Given the tension between US and Iran / Iraq

etc. no GCC country will want to continue with such dependence. Therefore the only source viable (at

least at this time) economically as well as politically is desalination of water.

Is desalination the way to go for upcoming markets like India & China?

Both India and China have abundant supply of natural potable water in the form of rainwater, rivers and

underground waters. However, both the countries face the issue of explosion of population and high

rate of industrialization which increase the pressure on these natural resources. The bigger problem is

wastage and extremely poor methods of conserving potable water.

In my view, these countries should invest more in improving water conservation methods and reduce

wastage rather than relying on desalination methods for future.



References

Pacific Institute, The World’s Water, 2009. Published in March 2010

(http://www.grida.no/publications/rr/sickwater)

Sustainable Development of Water Desalination and Energy Systems – Kuwait Case by

Naim Hamdia Afgan (UNESCO Chair Holder Technical University of Lisbon, Lisbon,

Portugal) http://www.kfas.com/information_pages/pdf-news/Prof-Naim-H-Afgan.pdf

Wikipedia ( http://en.wikipedia.org/wiki/Desalination)

Canadian Nuclear Association –

(http://www.cna.ca/curriculum/cna_nuc_tech/desalination-

eng.asp?bc=Desalination&pid=Desalination)

(Sommariva et. al., 2004, Leeden et. al. 1990; Howard 1985 Peavy et. al., 1985 and

others):

Planning for Desalination (GHD Fichter and Sydney Water, 2005

(http://www.ffc.org.au/FFC_files/desal/Whatisdesalination-factsheet-1.pdf )

The Global Desalination Market - Christopher Gasson (Global Water Intelligence)

(http://phx.corporate-

ir.net/External.File?item=UGFyZW50SUQ9Nzg3MnxDaGlsZElEPS0xfFR5cGU9Mw==&t=1)

http://environment.about.com/od/biodiversityconservation/a/desalination.htm

UNIVERSITIES COUNCIL ON WATER RESOURCES- JOURNAL OF CONTEMPORARY WATER

RESEARCH & EDUCATION by Tamim Younos (Virginia Polytectnic Institute and State

University) - http://www.ucowr.org/updates/132/3.pdf

Al-Mutaz, I. S. 1991. Environmental Impact of Seawater; Desalination Plants.

Environmental Monitoring and Assessment 16:75-8

http://www.grida.no/publications/rr/sickwater



http://www.kfas.com/information_pages/pdf-news/Prof-Naim-H-Afgan.pdf



http://en.wikipedia.org/wiki/Desalination



http://www.cna.ca/curriculum/cna_nuc_tech/desalination-eng.asp?bc=Desalination&pid=Desalination




http://www.ffc.org.au/FFC_files/desal/Whatisdesalination-factsheet-1.pdf



http://phx.corporate-ir.net/External.File?item=UGFyZW50SUQ9Nzg3MnxDaGlsZElEPS0xfFR5cGU9Mw==&t=1






http://www.ucowr.org/updates/132/3.pdf













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