production speaks in favour of solar saltworks
Salt Partners - ResearchGate
Salt Partners - ResearchGate
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Salt Partners<br />
Environmental balance <strong>of</strong> salt<br />
<strong>production</strong> <strong>speaks</strong> <strong>in</strong> <strong>favour</strong> <strong>of</strong><br />
<strong>solar</strong> <strong>saltworks</strong><br />
Vladimir M. Sedivy MSc (Hons) Chem Eng, IMD<br />
President<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Santor<strong>in</strong>i 2006
Salt Partners<br />
Salt <strong>production</strong> world-wide<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Salt type<br />
Solar salt<br />
Rock salt<br />
Br<strong>in</strong>es<br />
Total<br />
Santor<strong>in</strong>i 2006<br />
World <strong>production</strong><br />
80,000,000 t/y<br />
60,000,000 t/y<br />
70,000,000 t/y<br />
210,000,000 t/y
Salt Partners<br />
Salt consumption world-wide<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Salt user<br />
Chemical <strong>in</strong>dustry<br />
Food<br />
Other<br />
Santor<strong>in</strong>i 2006<br />
Salt consumption<br />
130,000,000 t/y<br />
60,000,000 t/y<br />
20,000,000 t/y
Salt Partners<br />
Ma<strong>in</strong> salt uses world-wide<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Caustic / Chlor<strong>in</strong>e 36%<br />
Soda Ash 17%<br />
Other Chemicals 3%<br />
Human Consumption 22%<br />
Road De-ic<strong>in</strong>g<br />
12%<br />
Other Uses 10%<br />
Santor<strong>in</strong>i 2006
Salt Partners<br />
Multiple Effect Crystallisation<br />
Steam<br />
turb<strong>in</strong>e<br />
G<br />
Generator<br />
Power<br />
Cool<strong>in</strong>g<br />
water<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Fuel<br />
Br<strong>in</strong>e<br />
Steam<br />
boiler<br />
Br<strong>in</strong>e<br />
purification<br />
Salt evaporation plant<br />
Vacuum salt <strong>production</strong> with cogeneration<br />
Santor<strong>in</strong>i 2006<br />
Salt
Salt Partners<br />
Prime energy consumption for multiple<br />
effect vacuum salt crystallisation<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Water evaporation<br />
Santor<strong>in</strong>i 2006<br />
3 t / t <strong>of</strong> salt<br />
Steam to first effect 10 – 12 bar g<br />
Number <strong>of</strong> effects 6<br />
Steam consumption<br />
0.62 t / t <strong>of</strong> salt<br />
Boiler efficiency 75%<br />
Prime energy consumption<br />
450 kWh / t <strong>of</strong> salt
Salt Partners<br />
Prime energy consumption for salt<br />
crystallisation by thermocompression<br />
with mechanical vapour recompression<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Water evaporation<br />
Power consumption<br />
Santor<strong>in</strong>i 2006<br />
3 t / t <strong>of</strong> salt<br />
160 kWh / t <strong>of</strong> salt<br />
Power generation efficiency 35%<br />
Prime energy consumption<br />
450 kWh / t <strong>of</strong> salt
Salt Partners<br />
Solar salt evaporation<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Sea water density 3.85°Bè<br />
NaCl content<br />
Santor<strong>in</strong>i 2006<br />
30.09 kg NaCl / m3<br />
Bitterns density 28.53°Bè<br />
NaCl <strong>in</strong> bitterns<br />
NaCl crystallised<br />
Water evaporated<br />
Water evaporation<br />
Heat <strong>of</strong> water evaporation<br />
8.37 kg<br />
21.72 kg<br />
949.93 kg<br />
43.74 t H2O / t NaCl<br />
0.675 kWh / kg H2O<br />
Solar energy consumption 29’520 kWh / t NaCl
Salt Partners<br />
Earth’s <strong>solar</strong> energy budget<br />
Santor<strong>in</strong>i 2006<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland
Salt Partners<br />
Solar energy on the planet Earth<br />
Santor<strong>in</strong>i 2006<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland
Salt Partners<br />
Solar energy conversion <strong>in</strong>to evaporation<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Earth <strong>in</strong>solation<br />
Santor<strong>in</strong>i 2006<br />
1.366 kW / m2<br />
Surface <strong>in</strong>solation absorbed 51%<br />
Solar energy absorbed <strong>in</strong> zenith<br />
Daily <strong>solar</strong> energy absorption<br />
Conversion efficiency 45%<br />
Daily <strong>solar</strong> evaporation energy<br />
Heat <strong>of</strong> water evaporation<br />
Daily evaporation<br />
0.697 kW / m2<br />
5 – 7 kWh / m2 / day<br />
2 – 3 kWh / m2 / day<br />
0.675 kWh / kg H2O<br />
3 – 5 kg H2O / day<br />
Annual evaporation 1.1 – 1.8 m H2O / year
Salt Partners<br />
Solar evaporation conversion <strong>in</strong>to salt<br />
Annual evaporation 1.1 – 1.8 m H2O / year<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Salt crystallised per tonne <strong>of</strong><br />
sea water evaporated<br />
Correspond<strong>in</strong>g salt <strong>production</strong> 27 – 44 kg NaCl / m2 / year<br />
Crystalliser area 10%<br />
Salt layer <strong>in</strong> crystallisers 270 – 440 kg NaCl / m2 / year<br />
Salt layer density<br />
Santor<strong>in</strong>i 2006<br />
22.86 kg / t H2O<br />
2 t / m3<br />
Salt layer thickness 13 – 22 cm
Salt Partners<br />
Conversion efficiencies<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Photovoltaic cells 8 – 15%<br />
Solar collectors with stirl<strong>in</strong>g<br />
eng<strong>in</strong>e<br />
Super critical steam power<br />
plants<br />
Santor<strong>in</strong>i 2006<br />
30%<br />
40 – 45%<br />
Solar salt <strong>production</strong> 45%
Salt Partners<br />
Impurities <strong>in</strong> salt<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Rock salt<br />
Sea salt<br />
Santor<strong>in</strong>i 2006<br />
Lake salt<br />
Br<strong>in</strong>es<br />
CaSO4 0.5 – 2% 0.5 – 1% 0.5 – 2% Saturated<br />
MgSO4<br />
Traces 0.2 – 0.6% Traces<br />
MgCl2 0.3 – 1% Traces<br />
CaCl2<br />
Na2SO4<br />
KCl<br />
NaBr<br />
Traces<br />
Traces<br />
Traces<br />
Traces<br />
Traces<br />
Traces<br />
Traces<br />
Traces<br />
Insolubles 1 – 30% 0.1 – 1% 1 – 10%<br />
Traces<br />
Traces<br />
Traces
Salt Partners<br />
What impurities <strong>in</strong> salt cause <strong>in</strong> mercury and<br />
membrane cells employed <strong>in</strong> chloralkali <strong>in</strong>dustry<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
• Hydrogen evolution<br />
• Mercury butter<br />
• Membrane damage<br />
• Incrustations<br />
• Sludge deposits<br />
Santor<strong>in</strong>i 2006
Salt Partners<br />
Cost <strong>of</strong> salt and br<strong>in</strong>e purification <strong>in</strong> the<br />
chloralkali <strong>in</strong>dustry<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Cost <strong>of</strong> br<strong>in</strong>e treatment<br />
and disposal<br />
(USD / t salt)<br />
Santor<strong>in</strong>i 2006<br />
Cost <strong>of</strong> salt, br<strong>in</strong>e<br />
treatment and disposal<br />
(USD / t salt)<br />
M<strong>in</strong>imum 1.45 11.09<br />
Average 9.20 25.09<br />
Maximum 27.42 49.35
Salt Partners<br />
Relative cost <strong>of</strong> salt and br<strong>in</strong>e purification <strong>in</strong><br />
the chloralkali <strong>in</strong>dustry<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Cost <strong>of</strong> br<strong>in</strong>e treatment as<br />
percentage <strong>of</strong> salt cost<br />
Santor<strong>in</strong>i 2006<br />
Percentage <strong>of</strong> chloralkali<br />
<strong>production</strong> cost<br />
% %<br />
M<strong>in</strong>imum 120 3.6<br />
Average 166 15<br />
Maximum 256 37
Salt Partners<br />
Three <strong>saltworks</strong> areas that are critical to<br />
<strong>production</strong> <strong>of</strong> high quality <strong>solar</strong> sea salt<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
•Sea water pre-concentration area<br />
•Solar salt crystallisation area<br />
•Salt purification plant<br />
Santor<strong>in</strong>i 2006
Salt Partners<br />
Sea water pre-concentration area<br />
Santor<strong>in</strong>i 2006<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland
Salt Partners<br />
What to do and what to avoid <strong>in</strong> the sea water<br />
pre-concentration area<br />
•Increase concentration gradually, avoid back-mix<strong>in</strong>g<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, S Switzerland<br />
•Prevent seepage<br />
•Cultivate dark pre-concentration pond bottom<br />
•Ma<strong>in</strong>ta<strong>in</strong> clear br<strong>in</strong>e<br />
•Avoid calcium sulphate over-saturation<br />
•Allow nutrients <strong>in</strong> br<strong>in</strong>e to get consumed<br />
Santor<strong>in</strong>i 2006
Salt Partners<br />
Solar salt crystallisation area<br />
•Employ crystallisers <strong>in</strong> series<br />
•Dra<strong>in</strong> 28.5°Bè br<strong>in</strong>e<br />
•Support growth <strong>of</strong> Halobacterium that<br />
colours the br<strong>in</strong>e red<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
•Allow thick br<strong>in</strong>e layer to avoid<br />
reflection <strong>of</strong> <strong>solar</strong> radiation<br />
•Avoid organic matter that causes<br />
formation <strong>of</strong> small crystal agglomerates<br />
•Harvest under level control to avoid<br />
salt contam<strong>in</strong>ation with <strong>in</strong>solubles<br />
Santor<strong>in</strong>i 2006
Salt Partners<br />
Solar salt from poorly managed <strong>saltworks</strong><br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Salt that looks like a<br />
crystal, but it is an<br />
agglomerate.<br />
The agglomerate can<br />
be broken by hand.<br />
Santor<strong>in</strong>i 2006<br />
Impurities are<br />
imbedded between the<br />
small crystal<br />
fragments.<br />
The salt is not well<br />
upgradeable.
Salt Partners<br />
Salt upgradability test, NaCl content<br />
Solar salt, India<br />
100<br />
HYDROSAL-XM/0.8<br />
Hydromill<strong>in</strong>g<br />
Shear crush<strong>in</strong>g<br />
99.8<br />
HYDROSAL-XC/0.8<br />
HYDROSAL-XM/3<br />
99.6<br />
HYDROSAL-XC/3<br />
99.4<br />
99.2<br />
99<br />
0 1 2 3 4 5 6<br />
Characteristic crystal size [mm]<br />
Santor<strong>in</strong>i 2006<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
NaCl (wt%)<br />
Raw salt HYDROSAL-XB
Salt Partners<br />
Solar salt from well managed <strong>saltworks</strong><br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
Hard, clear crystal, impossible<br />
to break by hand.<br />
Santor<strong>in</strong>i 2006<br />
Impurities are only on the crystal<br />
surface. The salt is very well<br />
upgradeable with low losses.
Salt Partners<br />
Salt upgradability test, NaCl content<br />
Salt Upgradability Test: NaCl content<br />
Santor<strong>in</strong>i 2006<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
HYDROSAL-XM/0.8<br />
HYDROSAL-XC/1.5<br />
HYDROSAL-XC/3.0<br />
Raw Salt 1996 HYDROSAL-XP<br />
Raw Salt 2006 HYDROSAL-XP<br />
100<br />
99.5<br />
99<br />
98.5<br />
98<br />
97.5<br />
97<br />
Test No.: 24/96-2 Test No.: 03/06<br />
NaCl [wt%]<br />
0 1 2 3 4 5 6 7 8 9<br />
Characteristic Crystal Size [mm]
Salt Partners<br />
SALEXPOR 15 t/h<br />
<strong>solar</strong> salt ref<strong>in</strong><strong>in</strong>g<br />
plant <strong>in</strong> Portugal<br />
Santor<strong>in</strong>i 2006<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland
Salt Partners<br />
100 t/h <strong>in</strong>dustrial<br />
salt upgrad<strong>in</strong>g<br />
plant <strong>in</strong> Spa<strong>in</strong><br />
Santor<strong>in</strong>i 2006<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland
Salt Partners<br />
Vladimir M. Sedivy<br />
Salt Partners Ltd, Zurich, Switzerland<br />
40 t/h salt upgrad<strong>in</strong>g<br />
plant <strong>in</strong> Portugal<br />
produc<strong>in</strong>g purest<br />
<strong>in</strong>dustrial salt <strong>in</strong> Europe<br />
Ca<br />
Mg<br />
SO4<br />
Performance test<br />
ppm 0.6<br />
ppm 0.2<br />
ppm 53<br />
Efficiency 97.4%<br />
NaCl losses < 4%<br />
Santor<strong>in</strong>i 2006
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