Comparison of SCC and RO
A comparison of SCC technology and Reverse Osmosis for alcohol reduction of wine is shown below:
| 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) | 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 | Possible to process wine with high level of suspended solids - clarity and stabilisation is not important |
| Alcohol removal technique | Separation based on Molecular Weight | 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) | 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%) | Alcohol content may be reduced from 15% to <1% abv in one pass |
| Residence time | Possibly many hours | 10 - 20 seconds per pass |
| Time to process 10,000L (15% abv reduced to 3% abv) | 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 | 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) | >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 | Low |
| Water removed | Yes - large volume of water removed. Water loss must be made up (possibly through treatment of RO permeate to recover water) | Negligble volume of water removed |
| Water consumption during processing | High water usage if pervaporation used to treat RO permeate. Treated water required | 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 | 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 | None |
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