MEMBRANE…..?

“Barrier which separates 2 phases & restricts transport of various

molecules in a selective manner”.

Driven by

• Pressure

• Concentration

• Temperature

• Electrical potential

Can be

Thick/Thin

Liquid/Solid

Symmetric/Asymmetric

Natural/Synthetic

Neutral/Charged

•MEMBRANE FILTRATION

Uses a physical barrier

Porous membrane or filter,

To separate particles in a fluid.

HISTORY:• IN 1748 - ABBE JEAN-ANTOINE NOLLET; French physicist

separated degassed alcohol using pig’s bladder.

• 1824, RENE-JOACHIM-HENRI DUTROCHET, French

physiologist introduced “osmosis”: movement of water through a

biological membrane

• 1861- THOMAS GRAHAM (FATHER OF MODERN DIALYSIS): coined

“dialysis “- separated dissolved substances based on mol.wt.,

& concentration.

• 1865 – MORITZ TRAUBE invented first artificial membrane using

Copper Ferro cyanide precipitates

• 1875- WILHELM FRIEDRICH PHILIPP PFERRER: Made the membranes

to withstand operational pressures

WORKING MECHANISM:

• MEMBRANE PROCESS: The feed stream is divided into two streams:

• Retentate (concentrate) stream

• Permeate stream

• Either the concentrate or permeate stream is the product of our interest.

•REPRESENTATION OF MEMBRANE SEPARATION

Driving Force

Feed

MEM

BRA

NE

Permeate

CLASSIFICATION OF

MEMBRANES

Pressure driven

Electrically driven

Pressure

driven

Ultra filtration

Micro

filtration

Reverse osmosis

Nano filtration

Concentration driven

Pervaporation

Dialysis

Gas separatio

n

Electrically driven

Mic

rofi

ltra

tion

Low pressure driven

(2 bar)

Membrane with an open structure

Allows-Dissolved particles

Rejects-Undissolved particles

APPLICATIONS•Bacterial reduction

•Fat removal in milk

•Whey as well as protein and casein standardisation

•Removal of casein from whey protein

ULTRA FILTRATION

Medium pressure driven

(1-10 bar)

Membrane with a medium open structure

Allows-Most dissolved , some undissolved particles

Rejects-Large particles

APPLICATIONS

•NANO FILTRATIONMedium to high pressure

driven

(5-40 bar)

Membrane with slightly more open structure

Allows-Monovalent ions

Rejects-Divalent ions

APPLICATIONS

•REVERSE OSMOSIS

High pressure driven

(10-100 bar)

Dense membrane

Allows only water

REVERSE OSMOSIS

APPLICATIONS

MEMBRANE CHARACTERISTICS

• Pore size:

• Microfiltration - 0.1 – 5µm

• Ultrafiltration - 0.01-0.1 μm

• Nano filtration - 0.001-0.01 μm

• Reverse osmosis- 0.0001 – 0.001 μm

• Temperature resistant <40ºC & 70-80ºC

• Pressure resistant

•ELECTRODIALYSIS• Semi permeable membrane

• Allows either positive or negative charged ions

• Under the influence of electricity

APPLICATIONS

Demineralization of dairy products

Demineralization of whey

Desalination of cheese whey

MEMBRANE FOULING

• Process where solute or particles deposit

• Onto a membrane surface or into membrane pores

• Degrades the membrane's performance.

Pre-treatment of the feed

solution

Membrane properties

.

Cleaning

a. Narrow pore size distributionb. Hydrophilic membranes

a. Heat treatmentb. pH adjustmentc. Chlorination

a. Hydraulic cleaning

b. Mechanical cleaning

c. Chemical cleaning

METHODS TO REDUCE FOULING

APPLICATIONS IN

DAIRY INDUSTRY

Extending shelf life

Desalting or demineralization

Fat

processing

Protein

processingCheese

industry

WASTE WATER TREATMENT

Whey processing

Lactose free milkHigh calcium

low fat milk Non fat yoghurt

High protein low fat

ice-creamLow lactose low fat

milkWhey based

beverage

Lactose free ice-cream

CONCLUSION

• Alternatives to conventional processing method.

• Cold pasteurization method

• Create products, ingredients with favorable characteristics

• Without the addition of chemicals, with low energy use.

• A very good technology for wastewater treatment.

FUTURE TRENDS

• Produce even higher-quality products at reasonable costs.

• Can apply ‘Reduce, reuse, recycle’

• Reuse of process waste water for water efficiency and security

improvement.

• Recycle is the process of converting waste materials into useful end

products

REFERENCE• Trevor Britz, Richard K. Robinson, Advanced dairy science and

Technology, Black well publishers Pg. no57-61

• By P. Walstra, Dairy technology: principles of milk properties and

processes ,Eastern hemisphere distribution, Pg. no 116-118

• Jelem p 1993,’’Pressure driven membrane processes; principles

definitions” New applications of Membrane processes, Brussels

Belgium:IDF pg. no7-14

• Www.Dairyprocessinghandbook.Com/chapter/membrane-technology

• JOURNAL OF FOOD RESEARCH AND TECHNOLOGY journal

homepage: www.Jakraya.Com/journa/jfrt