1. Comenius Project WAVE: water a vital element 2009-2011 Caltanissetta Project visit 15-18 March 2010 16/03/2010 ITI & LST “S. Mottura

2. 2 The desalinator at Gela by Guido Vinci Vincenzo Lanzalaco Francesco Di Stefano 16/03/2010 ITI & LST “S. Mottura

3. Gela 16/03/2010 ITI & LST “S. Mottura Where is Gela ?

4. Gela 16/03/2010 ITI & LST “S. Mottura What does Gela look like? Timolontee’s walls Cathedral Federico II little castle gorgonica mask

5. 5 16/03/2010 ITI & LST “S. Mottura The Gela Oil Refinery Oil Refinery is a public body. It entirely belongs to ENI (hydrocarbur national body) public limited company. It receives more than 5 million tons of raw material each year, of which more than 20% is made up of local raw materials that are converted in finished products to be sold on the market. Raw materials and finished products are mainly shipped by sea.

6. 6 ENI The refinery:  produces petroleum products( GPL, diesel fuel, petrol);  produces and exports electrical energy to 100 megawatt( enough to supply a town like Gela);  produces over 2.000 m3/h of desalinated water that is supplied to the public drinking water system in Agrigento, Caltanissetta and Gela.  treats Gela waste water;  manages Dirillo Dam whose water is used both for the refinery and agriculture.

7. The water cycle of Gela refinery 16/03/2010 ITI & LST “S. Mottura Water cycle Town Refinery Agriculture Dirillo Dam Desalinator Cooling Seawater waste water depurated Depurators Remineralisation

8. The water cycle Water cycle Town Refinery Agriculture Dirillo Dam Desalinator Cooling Seawater waste water depurated Depurators The Dirillo Dam waters both the territory of Gela and Niscemi. It provides water both for agriculture and refinery.The last one uses it for different industrial processes.

9. The water cycle 16/03/2010 ITI & LST “S. Mottura Water cycle Town Refinery Agriculture Dirillo Dam Desalinator Cooling Seawater waste water depurated Depurators Remineralisation Seawater is used by the refinery for its plant machinery and it cools various phases in the industrial process.

10. The water cycle 16/03/2010 ITI & LST “S. Mottura Water cycle Town Refinery Agriculture Dirillo Dam Desalinator Cooling Seawater waste waters depurated Depurators Remineralisation Town and industrial waste waters are depurated in the biological plants.They flow into the sea in their final process.

11. The water cycle 16/03/2010 ITI & LST “S. Mottura Water cycle Town Refinery Agriculture Dirillo Dam Desalinator Cooling Seawater waste waters depurated Depurators Remineralisation Seawater is impoverished of salt and soon after it is enriched with the right salt concentration necessary to render her drinkable water.Then it arrives to the town and Siciliacque (private company) provides water in the whole isle of Sicily. Remineralisation is an important process because it avoids serious illnesses such as ischemia and cardiovascular diseases.

12. 12 16/03/2010 ITI & LST “S. Mottura In the last years new technologies has permitted the creation of desalination plants. The countries interested are the Gulf countries covering 43% of the world desalination. The Desalinator When was the desalinator built? In 1974, the “Cassa per il Mezzogiorno”, a public body, built the biggest desalinator of Europe inside the oil refinery to cope with drinking water demand of Sicilian southern coast towns of the district of Caltanissetta and Agrigento. The desalinator is composed of four “Multi Flash” thermic moduls and by one reverse osmosis module.

13. Desalination Desalination, refers to the process that removes excess salt and other minerals from seawater. Water is desalinated in order to convert salt water to fresh water so it is 16/03/2010 ITI & LST “S. Mottura suitable for human consumption, irrigation or industrial use as cooling water.

14. Desalination techniques The techniques used for desalination process are: 1. techniques exploiting the water evaporation - multiple effect processes - solar evaporation processes - thermal compression process - multiple expansion process 2. techniques exploiting the freezing - direct freezing process 3. techniques based on the salt permeable membranes (electrodyalisis) 4. techniques based (on the use of ) ion exchange resins -ion exchange 16/03/2010 ITI & LST “S. Mottura

15. DESALINATION Processes based on the separation of water from salt processes based on the separation of salt from water Thermal processes Salt Extraction with solvents Membrane based processes Ionic exchange processes Inverse Osmosis Direct Osmosis Electrodylisis Humidification Dehumidification SteamTermal Compression Steam Mechanical Compression Steam compression absorption Steam compression adsorption Freezing processes Solar Panels

16. Desalination ELECTRICAL ENERGY MECHANICAL ENERGY THERMIC ENERGY ELECTRODYALISIS MECHANICAL STEAM COMPRESSION INVERSE OSMOSIS HEAT SUBTRACTION HEAT SUPPLY SOLAR ENERGY STEAM

17. Drinking water Steam Sea water Waste Condensate Multi Flash Desalinators Brine Heater The steam developed is condensed, gathered and sent to the following chamber. The pickle gathers at the bottom. Seawater arrives through pipes to the condenser. Here the evaporation takes place in the solution bulk due to a pressure decrease in the flashing chambers. This process is repeated n chambers and allows fresh water production from 4000 m 3 to 30.000 m 3 a day.

18. 16/03/2010 ITI & LST “S. Mottura Schematic of a multi-stage 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

19. 19 Nowadays, owing to lacking in fresh water we need a system that can use solar energy to get the maximum output at low costs. This opens up new prospects of marketing, especially in the Mediterranean area. On a regional level it should resolve the problem of isles water supplying, without using fossil resources that are getting more and more expensive. Multiflash solar desalinator

20. 20 Osmosis It is the movement of water molecules (solvent) across a semi-permeable membrane from a low concentrated solution to high concentrated solution. 16/03/2010 ITI & LST “S. Mottura

21. By applying a pressure to the most concentrated solution, the flow of solvent will be reversed. 16/03/2010 ITI & LST “S. Mottura Reverse Osmosis It works by using pressure to force a solution through a membrane, retaining the solute on one side and allowing the pure solvent to pass to the other side.

22. 22 16/03/2010 ITI & LST “S. Mottura Reverse osmosis plant The most efficient method to treat and to demineralise water is the reverse osmosis plant. Concentrated Water Desalinated Water Salty Water It is a device composed of a semi-permeable membrane and two pre-filters. The first has a mechanical action. The second is a carbon active filter. At the end there are two types of water. The first one is drinkable, and the second is waste water. Water passes through the two pre-filter and then througt an osmotic membrane. This membrane removes from 80 to 98 % of all other substances (salt, ions heavy metal, organic compound, but also incidental pesticide and bacteria).

23. 23 16/03/2010 ITI & LST “S. Mottura Thank you for your attention!