This document discusses water desalination techniques. It begins by introducing desalination as the process of removing minerals from saline water to produce fresh water for human consumption or irrigation. Currently 1% of the world's population relies on desalinated water but this is expected to rise to 14% by 2025 due to increasing water scarcity. It then outlines various desalination methods like multi-stage flash distillation, reverse osmosis, and ion exchange. These techniques are used widely in the Middle East and Australia. The document also compares the energy consumption of different desalination methods and discusses their drawbacks.

1. WATER DESALINATION
MARTIN DEGOS (EMSE)
WEI-TING SHIH (NTU)
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2. INTRODUCTION
• DESALINATION IS A PROCESS THAT REMOVES MINERALS FROM SALINE WATER.
• SALT WATER IS DESALINATED TO PRODUCE FRESH WATER SUITABLE FOR HUMAN
CONSUMPTION OR IRRIGATION.
• “AT THE MOMENT, AROUND 1% OF THE WORLD'S POPULATION ARE DEPENDENT ON
DESALINATED WATER TO MEET THEIR DAILY NEEDS, BUT BY 2025, THE UN EXPECTS
14% OF THE WORLD'S POPULATION TO BE ENCOUNTERING WATER SCARCITY”
CHRISTOPHER GASSON (GLOBAL WATER INTELLIGENCE)
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3. WHERE ARE THEY USED?
• Australia
• Many countries in the Middle East:
- The single largest desalination
project is Ras Al-Khair in Saudi
Arabia (1,025,000 cubic meters per
day)
- Israel  produces 40% of its
domestic water use from seawater
desalination
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4. METHODS
• DISTILLATION
• MULTI-STAGE FLASH DISTILLATION (MSF)
• MULTIPLE-EFFECT
DISTILLATION (MED|ME)
• VAPOR-COMPRESSION (VC)
• ION EXCHANGE
• MEMBRANE PROCESSES
• ELECTRODIALYSIS REVERSAL (EDR)
• REVERSE OSMOSIS (RO)
• NANOFILTRATION (NF)
• MEMBRANE DISTILLATION (MD)
• FORWARD OSMOSIS (FO)
• FREEZING DESALINATION
• Geothermal desalination
• Solar desalination
• Solar humidification-
Dehumidification (HDH)
• Multiple-effect humidification (MEH)
• Methane hydrate crystallization (fire ice)
• High grade water recycling
• Seawater greenhouse
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5. MULTISTAGE FLASH DESALINATOR
Schematic of a multistage flash desalinator
A – steam in
B – seawater in
C – potable water out
D – waste out
E – steam out
F – heat exchange
G – condensation collection
H – brine heater
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6. ION EXCHANGE
Ion exchange resin beads 6/12

7. REVERSE OSMOSIS
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8. ENERGY CONSUMPTION
Desalination
Method
Multi-stage
Flash
Multi-Effect
Distillation
Mechanical
Vapor
Compression
Reverse
Osmosis(RO)
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
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9. DRAWBACKS
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10. VIDEO
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11. REFERENCES
• HTTPS://EN.WIKIPEDIA.ORG/WIKI/DESALINATION
• HTTPS://EN.WIKIPEDIA.ORG/WIKI/THERMOHALINE_CIRCULATION
• HOW SEAWATER DESALINATION WORKS (YOUTUBE)
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12. THANKS FOR YOUR ATTENTION
ANY QUESTIONS?
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