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Reverse Osmosis |
Spinning Cone Column |
Volume of wine to be processed |
10 - 20% of total wine volume (function of initial wine concentration, target wine concentration and alcohol removed in dealcoholisation step)
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10 - 20% of total wine volume |
Stage at which wine may be treated |
Wine should be heat, cold and pectin stabilised and have been polish filtered to less than 50 NTU.
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Possible to process wine with high level of suspended solids - clarity and stabilisation is not important. |
Alcohol removal technique |
Separation based on MW.
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Separation is based on relative volatility. |
| Number of passes |
Multiple discrete alcohol removal passes if operated batchwise (usually operated continuously with long periods of recirculation).
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One pass for flavour stripping (flavour subsequently reincorporated) and one pass for dealcoholisation. |
Alcohol removal per pass |
Alcohol content reduced by 0.7% to 1.5% abv per pass (ie. at least 8 discrete passes required to reduce alcohol from 15% to 3%)
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Alcohol content may be reduced from 15% to <1% abv in one pass. |
Residence time |
Possibly many hours.
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10 - 20 seconds per pass |
Time to process 10,000L (15% abv reduced to 3% abv)
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Function of size of membrane system. |
1.25 hours for Flavour Strip and 5 hours for Alcohol Strip (using model SCC 10,000) |
Flavour considerations |
None - some flavour compounds readily pass through RO membranes.
Possible flavour adsorption (both volatile and non-volatile compounds onto membrane material).
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Flavour strip to recover volatile compounds for subsequent reincorporation. Flavour stored as high strength ethanol stream (ie. very stable). |
Strength of Alcohol removed |
<10% abv (must either be sent to drain or further processed to recover EtOH from water).
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>50% abv (ie. can be used immediately for brandy production, alco-pops etc.) |
Hold up volume |
High - dilution of product on startup and loss of product on shutdown.
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Low. |
Water removed |
Yes - large volume of water removed. Water loss must be made up (possibly through treatment of RO permeate to recover water).
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Negligble volume of water removed. |
Water consumption during processing |
High water usage if pervaporation used to treat RO permeate.
Treated water required.
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Negligible - seal water use only (recirculation of seal water possible).
No special requirements for type of water. |
Water and Chemical consumption during CIP |
Very high requirements of chemical to clean and recharge membranes.
Treated water required.
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Water used for initial rinse (before chemical CIP) and for final rinse (after chemical CIP). About 650 L of NaOH at 2% required for CIP. |
High cost consumables |
Yes - membrane cartridges.
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None. |