D. Xevgenos, K. Moustakas, D. Malamis, M. LoizidouUnit of Environmental Science & Technology

School of Chemical EngineeringNational Technical University of Athens

konmoust@central.ntua.gr

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ADAPTtoCLIMATE Conference27‐28 March 2014, Filoxenia Conference Centre, 

Nicosia, Cyprus

DESALINATION & SUSTAINABILITY: RENEWABLE ENERGY DRIVEN DESALINATION & BRINE MANAGEMENT 

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Fresh Water Availability (2007)

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Fresh Water Availability (2025)

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Global Water Distribution & Water Classification

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Fresh water availability

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Although the absolute quantities of freshwater on earth havealways remained approximately the same, the unevendistribution of water and human settlement continues tocreate growing problems on freshwater availability andaccessibility

Seawater and brackish water desalination has been proven tobe a technologically sound and promising option for combatingthe coming water crisis

Water Supply & Desalination

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Processes for water desalination

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Parameters for technology selection Quality of the feeding water (sea water, brackish)

Quantity and quality of produced water

Investment cost

Space availability

Energy requirements and availability

Personnel availability and experience

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Technical characteristics of the main desalination technologies

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Installed desalination capacity by process

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Electricity consumption in RO plants depending on feedwater quality

The per m3 consumption of electric energy depends on thefeedwater as follows:

Seawater: 4 ‐ 7 kWh/m3

Brackish water: 1 – 3 kWh/m3

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Desalination & Energy

Expensive, high energy demand, combined use of fossil fuels and the grid

CO2 emissions and dependence on the availability of grid

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Energy autonomy, low operational costs and operation capacity

in isolated areas.

Improvement of the carbon footprint, reduction of the

emissions.

Renewable Energy Sources

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Renewable Energy Source – Desalination, RES‐D) :

Solar Energy

Wind Energy

Geothermal Energy

Wave energy

Renewable Energy Sources

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Wind Energy ‐ Desalination

Wind turbine –

RO

(Irakleia, 2007)

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Geothermal Energy‐Desalination

Geothermal  pump–

MED

(Kimolos, 2007)

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Wave energy ‐ Desalination

(Orkney, Scotland, 2009)

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Solar Multiple Effect Humidification

Jeddah, Saudi ArabiaFPC ‐MEH

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Solar MΕD

Almeria, SpainPTC ‐MED

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Solar‐Membrane Distillation

Grand Canaria, SpainFPC ‐MD

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PV ‐ RO

Amellou, MoroccoPV ‐ RO

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PV ‐ RO

Tazekra, MoroccoPV ‐ RO

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PV ‐ RO

Tangarfa, MoroccoPV ‐ RO

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PV ‐ RO

Azla, MoroccoPV ‐ RO

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RES – Desalination Combinations

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SOL-BRINE: Concept

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Literature Review

Suggestions for full scale 

implementation

ConstructionDesign of the prototype

Overall evaluation (LCA, economic etc.)

Operation& Optimization

Methodology

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Innovative aspects of the project

Total brine elimination. The system has been designed in line with theZero Liquid Discharge principle

Water Recovery (>90%)

Production of useful end‐products. Through the operation of theprototype system the following two products are produced: (a) distilledwater of high quality and (b) dry salt. These products have potentialmarket opportunities.

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Innovative aspects of the project

Energy autonomous operation. Solar thermal collectors are used fordelivering hot water (10 KWth at approximately 70oC) and a photovoltaicgenerator (10 kWel) for electricity. All energy requirements are coveredexclusively through the use of solar energy

Use of state‐of the art technology: the evaporation of water is realizedthrough custom designed vacuum evaporation technology (evaporator andcrystallizer) and solar dryer

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The innovative SOL-BRINE system comprises:

(a) the energy supply system and

(b) the brine treatment system

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Single line diagram

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Mass Balance

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Brine treatment system

The brine treatment system (capacity: ~ 1m3/day)  is consisted of  the following units:

(a) Evaporator

(b) Crystallizer

(c) Solar Dryer

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Evaporator unit

Figure: View of the evaporator (installed on site)

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Crystallizer

Both the crystallizer and the evaporator unit are based on the physical process of vacuum evaporation. The crystallizer is consisted of a single vessel maintained at lower levels of pressure (normal operating conditions: 5kPa  0.05 atm(a)). The crystallizer unit is equipped with scraping blades inside the boiling vessel for allowing high evaporation rates through cleaning of the heat transfer surfaces from the formed salt crystals and good agitation. 

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Crystallizer

Its purpose is to crystallize the brine effluent, producing a slurry (magma) with humidity levels of approximately 50%. The whole process is characterized by energy efficiency through the combined use of vacuum technology and heat pump.

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Crystallizer unit (installation)

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Crystallizer unit

Figure: View of the crystallizer (installed on site)

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Solar Dryer (installation)

Dryer unit

Figure: View of the dryer (installed on site)

Thank you for your attention!

konmoust@central.ntua.gr