Membrane seperation in milk technology

1. Membranefiltrationapplications
• Reverseosmosis(RO(
• Concentration of solution byremovalof water
• Nanofiltration(NF(
• Concentration of organic componentsbyremovalof part of
monovalentionslikesodiumandchlorine(partial
demineralisation)
• Ultrafiltration(UF(
• Concentration of largeandmacromolecules
• Microfiltration(MF(
• Removalof bacteria,separation of macromolecules

2. Filtrationprocesses
Monovalent
Water ions Multivalent
ions
Virus
Bacteria
Suspended
solids
MF
UF
NF
RO

4. Traditional membrane filtration

5. Membranematerial
• Membranes maybecomposedof natural (e.gmodified natural
cellulosepolymers) or syntheticpolymers(plastic materials)or
inorganic ceramicmaterials
• begoodfilm formers,
• managehigh permeateflows,
• havehigh selectivity,
• havegoodchemical andbacteriologicalresistance,
• beresistanttodetergents anddisinfectants,
• beinexpensive.

6. Membranematerial–celluloseacetate
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• Mostlyfor ROandUF
• Advantages
• easyto manufacture,provide high flux andhavehigh salt
rejectionproperties
• Disadvantages
• limited temperaturerange(max30°C)
,
• limited pHrange (pH3-6)–problem for cleaning with
detergents
• poorresistance tochlorine asasanitiser,
• poormembranepropertiesat high operating pressures
• susceptibility tomicrobialattackduetotheir natural origin

7. Membranematerial –syntheticpolymers
• Polyamideandpolysulphone
• Widelyusedfor UF
• WidetolerancetopH,temperatureandchlorine
Membranematerial–ceramic
• Madefrommineralmaterialssuchasglass,aluminium
oxideandzirconiumoxide
• Highresistancetochemicaldegradation, andtolerate
widepHandtemperatureranges
• Expensiveandcanbebrittle
• Mainlyusedfor microfiltration

8. Membranemodules
• Plateandframe
• Spiral wound
• Tubular,basedonpolymers
• Tubular,basedonceramics
• Hollow-fibre
Feed
Oval shaped
Rectangle shaped
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Retentate
Permeate

9. PlateandFramemodule SpiralWoundmembrane
Hollowfibremembrane

10. Membranefouling
MeansFormationof deposits
• Surface(temporary) fouling
• Pore(permanent) fouling
• Implications
• Moreenergyconsumption
• Durationof continuousoperationwithout needfor
cleaning
• Membranedurability
• Properties andqualityof concentrate
• Overall economyofthemembraneprocess

11. ApplicationsofUFindairyindustry
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• Proteinstandardisation
• Milksolidsfortificationforyogurt
• Cheese
• Increasedyield
• Wheyproteinconcentrateandisolate(WPC/WPI)
• Proteinconcentration
• MilkproteinconcentrateandIsolate(MPC/MPI)
• Proteinconcentration