A project topic for First years Engineering students in Chemistry and environmental studies. It is suggested to perform the stated experiment separately and let me know if you have any problems! Hope it helps!

1. DESALINATION OF SEA
WATER
CHY1001 CHEMISTRY PROJECT FIRST SEMESTER
Batch :- BME08
Submitted to Prof. Akella Shivaramakrishna

2. MEMBERS OF THE GROUP INVOLVED:
BATCH REGISTRATION NO. NAME
BME08 16BME0357 ABHISHEK SAVANI
BME08 16BME0368 ABHINAV AGRAWAL
BME08 16BME0653 MAYANK AGRAWAL
BME08 16BME0723 RISHAVDEB GHOSH
BME08 16BME0798 NEELANJYAN DUTTA
BME08 16BME0896 NEEL NADKARNI
BME08 16BME0922 UJJWAL MANI SHUKLA
BME08 16BME0923 SRIVATSAN C.
BME08 16BME0978 SHOMI DEEP MAULIK
BME08 16BME0987 JEFFREY THOMSON STANLY
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3. INTRODUCTION : Significance
 Desalination process helps remove
minerals from sea water to make it
consumable.
 75% of the Earth’s surface
is covered by water
 97.5% of that water is oceans
 Only 1% is available for drinking
 Desalination is particularly relevant in
dry countries such as Australia, which
traditionally have relied on collecting
rainfall behind dams for water.
 1.5 billion people lack ready access
to drinking water
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4. The Primary process of desalinating sea-water to obtain potable
water
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evaporator
condenser
membrane
evaporator
condenser
saltwater
vapour
brine
vapour
waste tank
clean water
water
Water
drinking
water
brine
brine

5. VARIOUS PROCESSES AVAILABLE FOR
DESALINATION :
 REVERSE OSMOSIS
 Distillation
 Multi-stage Flash
 Multi-Effect Distillation
 Electro Dialysis
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6. 1. REVERSE OSMOSIS
 This is an example of membrane
desalination process.
 Saltwater is forced through
membrane sheets at high pressures
 Semi-Permeable Membrane sheets
are designed to catch salt ions
 Process produces clean water and
brine
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In case of Reverse Osmosis, Saltwater is forced
through a membrane at 600 to 1000 psi to overcome
the vapor pressure of the saline water.
LIMITATIONS
BACK

7. Detailed Study of Reverse Osmosis:-
 Reverse osmosis or hyper filtration is
actually a way of filtering water to
reduce particles to a molecular level. It
significantly decreases the salts and
other potential impurities in the water,
resulting in a high quality and great-
tasting product.
 Reverse osmosis is comparatively newer
method of treating water and purifying it
but has emerged to be one of the best.
 Reverse osmosis (RO) is a water
purification technology that uses
a semi-permeable membrane to
remove ions, molecules, and larger
particles from drinking water. In
reverse osmosis, an applied pressure
is used to overcome osmotic
pressure, a colligative property, that
is driven by chemical
potential differences of the solvent, a
thermodynamic parameter. Reverse
osmosis can remove many types of
dissolved and suspended species from
water, including bacteria, and is used
in both industrial processes and the
production of potable water.
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8. What is a “Semi-permeable
Membrane”?
 A semipermeable membrane, also termed a selectively permeable membrane (or a differentially or
partially permeable membrane), is a type of biological or synthetic, polymeric membrane that will
allow certain molecules or ions to pass through it by diffusion—or occasionally by more specialized
processes of facilitated diffusion, passive transport or active transport. The rate of passage depends
on the pressure, concentration, and temperature of the molecules or solutes on either side, as well as
the permeability of the membrane to each solute. Depending on the membrane and the solute,
permeability may depend on solute size, solubility, properties, or chemistry.
 An example of a biological semi-permeable membrane is the lipid bilayer, on which is based
the plasma membrane that surrounds all biological cells. A group of phospholipids(consisting of a
phosphate head and two fatty acid tails) arranged into a double-layer, the phospholipid bilayer is a
semipermeable membrane that is very specific in its permeability. The hydrophilic phosphate heads
are in the outside layer and exposed to the water content outside and within the cell.
The hydrophobic tails are the layer hidden in the inside of the membrane. The phospholipid bilayer is
the most permeable to small, uncharged solutes. Protein channels float through the phospholipids,
and, collectively, this model is known as the fluid mosaic model.
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9. Semi-permeable Membrane:-
 The diffusion of water through a
selectively permeable membrane is
called osmosis. This allows only certain
particles to go through including water
and leaving behind the solutes including
salt and other contaminants. In the
process of reverse osmosis, thin film
composite membranes (TFC or TFM) are
used. These are semipermeable
membranes manufactured principally
for use in water
purification or desalination systems.
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10. Steps Involved in Reverse Osmosis
 1st Step - Removal of sediments from the water. In this step all the sediments like clay, silt
and stones are removed from the water. For this, a 5-micron filter is used. The sediments
are filtered in order to make sure that no damage is done to the membrane. The micron
filter does not let these particles pass by and thus they are suspended.
 2nd Step - The Reverse osmosis treatment is the usage of carbon filter. The carbon filter is
used to remove the chlorine and other harmful chemicals that enter the water sources. The
chemicals can be harmful to human health and thus it is necessary to remove them.
 3rd Step - Reverse osmosis treatment generally focuses on passing the water from a dense
and compacted carbon filter. The water that we get may have some unpleasant
characteristics and this third step helps in the removal of all such characteristics. All the
contaminants left in the water are removed at this stage and water becomes almost clean.
 4th Step - Water passes through the membrane and all the heavy metals present in the water
are removed. Along with the metals, radioactive metals too are removed. In this step, the
impurities are drained out of the reverse osmosis system and clean water is separated.
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11.  5th Step - The whole process of reverse osmosis is post filtration. This may be the
last step but is the most important of all. In this last stage, the bacteria, chlorine,
and bad odour are removed from water. After water passes from this stage, it
comes out of the faucet and is perfect for consumption.
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12. Limitations of R.O. Process :
 Because of low back pressure in household systems; about 85% of the water entering
the plant is not recovered as clean.
 Due to the selectively permeable membrane in use, the water is mostly
demineralised, i.e. ,the water is devoid of important minerals.
 Depending upon the desired product, either the solvent or solute stream of reverse
osmosis will be waste.
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BACK
R.O. Plant in Barcelona, Spain

13. 2.Distillation
 Distillation is a process of separating the
component substances from a
liquid mixture by
selective evaporation and condensation.
 In case the process exploits differences
in the volatility of mixture's
components.
 Different types of Distillation Processes
performed in laboratory:-
• Simple distillation
• Fractional Distillation
• Steam Distillation
• Vacuum Distillation
• Short-path Distillation
• Zone Distillation
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BACK

14. A New Approach for the Removal of
Salts from Sea Water
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15. Method of Desalination
Salt Water (RO Reject) + Hydrophilic
directional solvents (Adepic Acid)
Heating thoroughly
Salt will come out of water dissolved
mostly in the directional solvent(high
concentration)
Water + Adepic acid mixture is without
salt cooling
Pure Water Adepic acid
Zero Water Wastage
R.O. Membrane(Thin Film Composite)

21. Energy Consumption of Seawater
Desalination methods:-
 Energy consumption of seawater desalination has reached as low as 3 kWh/m3 including
pre-filtering and ancillaries, similar to the energy consumption of other fresh water
supplies transported over large distances but much higher than local fresh water supplies
that use 0.2 kWh/m3 or less.
 A minimum energy consumption for seawater desalination of around 1 kWh/m3 has been
determined, excluding pre-filtering and intake/outfall pumping. Under 2 kWh/m3 has been
achieved with Reverse Osmotic membrane technology, leaving limited scope for further
energy reductions.
 Supplying all US domestic water by desalination would increase energy consumption by
around 10%, about the amount of energy used by domestic refrigerators. Domestic
consumption is a relatively small fraction of the total water usage.
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22. 22
Desalination
Method
Multi-stage
Flash (MSF)
Multi-effect
Distillation
Simple
Distillation
Reverse
Osmosis
Electrical energy
(kWh/m3)
4–6 1.5–2.5 7–12 3–5.5
Thermal energy
(kWh/m3)
50–110 60–110 None None
Electrical
equivalent of
thermal energy
(kWh/m3)
9.5–19.5 5–8.5 None None
Total equivalent
electrical energy
(kWh/m3)
13.5–25.5 6.5–11 7–12 3–5.5

23. Cogeneration
 Cogeneration is generating excess heat and electricity generation from a single
process. Cogeneration can provide usable heat for desalination in an integrated,
or "dual-purpose", facility where a power plant provides the energy for
desalination. Alternatively, the facility's energy production may be dedicated to
the production of potable water (a stand-alone facility), or excess energy may be
produced and incorporated into the energy grid. Cogeneration takes various
forms, and theoretically any form of energy production could be used. However,
the majority of current and planned cogeneration desalination plants use
either fossil fuels or nuclear power as their source of energy. Most plants are
located in the Middle East or North Africa, which use their petroleum resources
to offset limited water resources. The advantage of dual-purpose facilities is
they can be more efficient in energy consumption, thus making desalination
more viable.
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24.  The current trend in dual-
purpose facilities is hybrid
configurations, in which the
permeate from reverse osmosis
desalination is mixed with
distillate from thermal
desalination. Basically, two or
more desalination processes are
combined along with power
production. Such facilities have
been implemented in Saudi
Arabia at Jeddah and Yanbu.
 A typical Super-carrier in the US
military uses nuclear power to
desalinate 400,000 US gallons
(1,500,000 l; 330,000 imp gal) of
water per day.
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The Shevchenko BN350, a nuclear-heated desalination unit

25. Economics
 Costs of desalinating sea water
(infrastructure, energy, and maintenance)
are generally higher than fresh water from
rivers or groundwater or water recycling or
conservation, but alternatives are not
always available. Desalination costs in 2013
ranged from US$0.45 to $1.00/cubic metre
($US2 to 4/kgal). (1 cubic meter is about
264 gallons.) More than half of the cost
comes directly from energy cost, and since
energy prices are very volatile, actual costs
can vary substantially.
 The cost of untreated fresh water in the
developing world can reach US$5/cubic
metre.
 Factors that determine the costs for
desalination include capacity and type of
facility, location, feed water, labour, energy,
financing and concentrate disposal.
Desalination plants control pressure,
temperature and brine concentrations to
optimize efficiency. Nuclear
powered desalination might be economical
on a large scale.
Area/Country Desalinated Water
Cost US$/person/day
USA 0.38
Europe 0.19
Africa 0.06
UN recommended 0.05
Israel 0.40
Singapore 0.49
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26. Desalination Worldwide
Plant Name/Location
Capacity
(mgd)
Tampa Bay Desalination
Plant, USA
25.0
Point Lisas, Trinidad 28.8
Almeria, Spain 13.2
Las Palmas – Telde 9.2
Larnaca, Cyprus 14.2
Muricia, Spain Design-Bid-
Build
17.2
The Bay of Palma/Palma de
Mallorca
16.6
Dhekelia, Cyprus 10.6
Marbella – Malaga, Spain 14.5
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27. Large R.O. Seawater Desalination
Plants In Design/Construction
Plant Name/Location Capacity Installed/Avg. (mgd)
Fujairah, UAE 45
Carboneras – Almeria, Spain 32
Ashkelon, Israel 35.4 expandable to 75
Singapore 36
Cartagena – Mauricia, Spain 17.2
Campo de Cartagena – Mauricia, Spain 37
Almeria, Spain 13.2
Alicante, Spain 13.2
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28. Bibliography :
 Class notes
 Book(s) : Engineering Chemistry
 Jain & Jain
 O.G. Palanna
 en.wikipedia.org
 Google images.
 Central Library, VIT University-Vellore
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