Desalination Technologies

Mapping by Separation Principle of Water & Salt

Selective Vaporisation / Evaporation due to Vapour Pressure Difference between Water and Salt  Selective Crystal Formation under Rejection of Salts Selective Membrane Preability for Water and Salt Selective Movement of Ions according to their Charge Selective Exchange of Ions on Surfaces
Addition of Heat (from outside the System*) Addition of Heat (from inside the System*) Pressure Elevation Pressure Elevation Electric Potential Difference Selective Exchange of Ions on Surface
Multi-Effect Distillation (MED) Humidification-Dehumidification (HD) Hydrate - based Desalination (HBD) Reverse Osmosis (RO) Electrodialsysis (ED) / ED Reversal (EDR) Ion Exchange
Thermal Vapour Compression (TVC) Membrane Distillation (MD)      Pressure Reduction and / or Addition of Heat Electrodeionisation (EDI)           
Mechanical Vapor Compression (MVC) Rapid Spray Evaporation (RSE) Pervaporaton (PV) Capacitive Deionisation (CDI)
Adsorption Desalination (AD)            
Vacuum Membrane Distillation (VMD)
Flashing (under Addition of Heat from inside the System*) Removal of Heat Osmotic Pressure Difference Bio-Electric Potential Difference
Multi-Stage Flash (MSF) Freeze Desalination (FD) Forward Osmosis (FO) Microbial Desalination Cell (MDC)
Direct Spry Distillation (DSD)             
Ocean Thermal Energy Desalination (OTED)
Vaporisation Evaporation
Monday, 22 May 2017 12:24

Desorption

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  1. Technical Description
  2. Plant Design
  3. Feed Water
  4. Desalinated Water & Brine
  5. Data and Information
  6. Preferred Use
  7. Environmental Impact
  8. Stage of Maturity
  9. Further Developments
  10. References

1. Technical Description


 

Desorption is a technology to remove ions from water by applying an electrical voltage difference between two porous carbon electrodes, in which ions will be temporarily stored.

CDI is a technology also known as Electrochemical Demineralization 〈1〉 or as Electrosorption 〈2〉. CDI's preferred use is in low salinity desalination applications (in principle below 10,000 ppm (1), in practice below 4,000 ppm (4)), where the benefit is lower energy consumption and higher recovery rates in comparison to Reverse Osmosis (RO) or distillation as alternative methods of brackish water desalination. This is mainly because CDI removes only salt ions, i.e. a tiny mass, from the salty feed water, whereas in RO or distillation a massively larger mass of water is removed from the salty feed water (1).

 

2. Plant design


 

The humidification dehumidification (HD) process uses the temperature dependence of the vapour pressure of water in air. The vapour pressure of water in air at saturation rises exponentially with the temperature. The dependence can be approximated e.g. by the Antoine equation:

Read 5638 times Last modified on Monday, 22 May 2017 12:25
More in this category: « Sorption Electrosorption »

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