2. CONTENTS
MEMBRANE
TECHNOLOGY
2
INTRODUCTION
MEMBRANE SEPARATION PROCESS
TYPES OF MEMBRANES
CATEGORIES OF PRESSURE DRIVEN
MEMBRANE PROCESSES
REVERSE OSMOSIS (RO) OR
HYPERFILTRATION
FACTORS CONTROLLING MEMBRANE
PROCESSING
MEMBRANE CONFIGURATION AND MODULES
MODES OF MEMBRANE FILTRATION
ADVANTAGES OF MEMBRANE TECHNOLOGY
MAJOR MEMBRANE MODULES
MEMBRANE FOULING
APPLICATIONS OF MEMBRANE TECHNOLOGY
IN FOOD PROCESSING
3. INTRODUCTION
MEMBRANE
TECHNOLOGY
3
Membrane technology is defined as a broad term that contains several
separation processes on molecular level i.e., membrane separation
usually applied on < 10 µm size molecules.
Membrane separation is performed above the atmospheric pressure
(that varies with particular membrane process) in a closed system so,
these processes are known as pressure-driven membrane processes.
4. PRINCIPLE OF MEMBRANE
SEPARATION
• Membrane separation involves a semipermeable membrane that
selectively permits certain molecules or ions to pass through while
blocking others.
• Membrane separation is driven by a pressure difference between the
feed and permeate sides of the membrane.
• The pressure difference causes the mixture to flow through the
membrane.
• The permeate, which is the liquid or gas that passes through the
membrane, is collected on the other side.
• The selectivity of the membrane is determined by its pore size, surface
charge, and hydrophilicity.
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MEMBRANE
TECHNOLOGY
5. MEMBRANE SEPARATION PROCESS
• Feed system is divided into two streams
:
I. Retentate
II. Permeate
• Either the concentrate (retentate) or
filtrate(permeate) is the product of
interest of any membrane filtration
process.
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MEMBRANE
TECHNOLOGY
7. TYPES OF MEMBRANE
FILTRATION
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MEMBRANE
TECHNOLOGY
Microfiltration (MF) Ultrafiltration(UF) Nanofiltration(NF)
Reverse
Osmosis(RO)
Pore size
(µm)
10-0.1 0.01 0.001 <0.0001
Operating
pressure(bar)
< 1 1-10 20-40 30-60
Basis of
rejection
Absolute size of
particles(0.02-10µm)
MWCO (103-105)
MWCO(200-
1000Da)
MWCO
Solutes to be
separated
Clay, paint, oil
droplets, suspended
matters,
microorganisms
Pectin’s, proteins,
high mol. wt.
polyphenols,
enzymes
Sugars, low mol. Wt.
polyphenols , dyes.
Salts, electrolytes.
Purpose Clarification or
turbidity removal
Clarification or
turbidity removal
Decolorization and
purity increase
Concentration and
desalination
8. REVERSE OSMOSIS
OSMOSIS REVERSE OSMOSIS
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MEMBRANE
TECHNOLOGY
The molecules of a solvent pass from
a solution of low concentration to a
solution of high concentration through
a semi-permeable membrane.
10. TYPES OF MEMBRANE
MATERIALS
1. Based on material composition
• Inorganic membranes
Can resist high temperature process streams.
Lowest pore size attainable is micron range.
Examples: Ceramic, alumina, zirconia, etc.
• Polymeric membranes
Temperature limitation, maximum 900C.
Can control the pore size, tune up to angstrom level.
Examples: Cellulose acetate (CA), polysulphone (PS), polyether sulphone (PES),
polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF).
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11. TYPES OF MEMBRANE MATERIALS
2. In terms of developmental stage
• 1st generation membranes
1st membrane used in commercial scale was cellulose acetate (CA)
membrane .
These are prepared as 0.1-1µ thick skin; are held with thicker porous
supports.
They are pH (2-8) dependent and limited to temperature(< 400C).
Require very frequent cleaning due to problem of clogging.
• 2nd generation membranes
Polymeric membranes which are made of polyamide (PA), PS, PAN, PVDF,
etc.
These are much resistant to pH variations and higher temperature than CA
membranes.
• 3rd generation membranes
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MEMBRANE
TECHNOLOGY
12. MODES OF MEMBRANE FILTRATION
1. DEAD END FLOW
FEED FLOW IS PERPENDICULAR TO THE
MEMBRANE SURFACE.
DEAD END FLOW CAUSE A LARGE
REDUCTION IN THE FLUX .
2. CROSS FLOW
FLOW OF SOLUTION IS PARALLEL TO THE
MEMBRANE SURFACE.
FLOW CAUSES TURBULENCE AND
PRODUCES SHEAR.
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MEMBRANE
TECHNOLOGY
13. ADVANTAGES OF MEMBRANE
TECHNOLOGY
MEMBRANE
TECHNOLOGY
1 3
Cost-effective and energy-efficient method for separating and purifying substances.
Environmentally friendly and reduces operational costs.
Produces high-quality and pure products, ideal for the food and beverage industry.
Easily automated and scalable.
Can recover valuable substances from waste streams, improving sustainability.
Removes microorganisms, viruses, and bacteria, making it a popular method for
sterilization and disinfection.
Can be used in conjunction with other separation technologies for greater efficiency
and purity.
14. MAJOR MEMBRANE MODULES
1. Flat sheet:
a) Spiral wound module:
• Compact layout
• The basic unit is a sandwich of flat membrane
sheets called a “leaf” wound around a central
perforated tube.
• One leaf consists of two membrane sheets placed
back to back and separated by a spacer called
permeate carrier.
• Layers of the leaf are glued along three edges,
while the unglued edge is sealed around the
perforated central tube.
• Feed water enters the spacer channels at the end of
the spiral-wound element in a path parallel to the
central tube.
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MEMBRANE
TECHNOLOGY
15. MEMBRANE
TECHNOLOGY
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• Filtered water in the permeate carrier travels spirally inward toward the
central collector tube, while water in the feed spacer that does not
permeate through the membranes continues to flow across the
membrane surface.
• This concentrate stream exits the element parallel to the central tube
through the opposite end from which the feed water entered.
• Relatively large amount of membrane area per element.
• Good cost- effective solutions to high volume applications.
• Primary advantage is of low capital investment and energy costs.
• Available for all types of filtration from microfiltration to reverse osmosis
16. PLATE AND FRAME
MODULE
• The earliest module designs were based
on simple filters and consisted of flat
sheets of membranes confined in a filter
press called “plate-and-frame” modules.
• Due to its simplicity, these plate and frame
modules have been widely used in lab-
scale and industrial applications.
• Surface to volume ratio (m2/m3) is typically
350-500 for plate and frame modules.
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17. TUBULAR MODULE
• Tube like structures with porous walls.
• Work through tangential cross flow.
• Highly resistant to plugging.
• Tubular membranes are typically used when the
feed stream contains large amounts of suspended
solids or fibrous compounds.
• Tubular modules consist of a minimum of two tubes:
i. the inner tube, called the membrane tube, and
ii. The outer tube, which is the shell
• The feed stream goes across the length of the
membrane tube and is filtered out into the outer
shell while concentrate collects at the opposite end
of the membrane tube.
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MEMBRANE
TECHNOLOGY
18. HOLLOW FIBRE
MODULE
• Fibers can be bundled
together longitudinally, potted
in a resin on both ends, and
encased in a pressure vessel.
• Extremely high packing
density.
• High open channel design,
high contact surface to
volume ratio(7000-13000
m2/m3).
• Offers the possibility of
backwashing from the
permeate side, particularly
suited for low solids liquid
streams.
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MEMBRANE
TECHNOLOGY
19. MEMBRANE FOULING
• A phenomenon where solute or particles either deposit onto the membrane surface(concentration polarization)or
held into membrane pores (pore blocking) in a manner that degrades the membranes performance (in terms of
productivity and quality).
• Major foulants are bacterial growth, organic materials, biological materials, colloidal and suspended matters.
• Major factors influencing the rate of fouling are membrane properties, feed solution composition, and operating
conditions.
• Additionally, process duration and mode of filtration (dead end or cross flow) affect the rate of local increase of
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MEMBRANE
TECHNOLOGY
20. CONSEQUENCES OF FOULING
MEMBRANE
TECHNOLOGY
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• During filtration process, the longterm loss in
membrane process throughout or performance
capacity is primarily due to two phenomena:
a. Concentration polarization: Formation of a
boundary layer that builds up ( as cake or
gel) on the membrane surface.
b. Pore blocking: Blockage of membrane
pores i.e. deposition within the membrane.
• The formed boundary or gel layer acts as a
secondary membrane and rejects smaller
solutes also, reducing the native design
selectively of the membrane.
21. MEMBRANE
TECHNOLOGY
2 1
Pre-treatment of feed
solution.
Periodic pulsing filtrate
(Backwashing).
Periodic membrane
cleaning with acid-alkali
treatment.
Increasing shear by
rotating or vibrating
METHODS TO
REDUCE
FOULING
22. APPLICATION OF MEMBRANE
TECHNOLOGY IN JUICE INDUSTRY
MEMBRANE
TECHNOLOGY
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Clarification: Microfiltration and ultrafiltration membranes are commonly
used to remove suspended solids, bacteria, and other impurities from
juice.
Concentration: Reverse osmosis and nanofiltration membranes are
commonly used for juice concentration by removing water.
De-acidification: Nanofiltration and RO is used to remove acid from
acidic juices, such as orange juice.
Aroma recovery: Permeation through membrane is used to recover
aroma compounds from juices.
Fractionation: Nanofiltration and ultrafiltration membranes are used to
fractionate juice into different components, such as separating pulp from
juice or separating different types of sugars.
23. APPLICATION OF MEMBRANE
TECHNOLOGY IN DAIRY INDUSTRY
MEMBRANE
TECHNOLOGY
2 3
Milk and whey processing: Ultrafiltration and microfiltration membranes
are used to concentrate and fractionate milk and whey proteins.
Cheese production: Ultrafiltration and nanofiltration membranes are used
for cheese production to concentrate and purify milk proteins and remove
lactose.
Clarification: Microfiltration and ultrafiltration membranes are used to
remove bacteria and other impurities from milk and whey.
Concentration: Reverse osmosis and nanofiltration membranes are used
to concentrate milk and whey by removing water.
Standardization: Membrane filtration can be used to standardize the
composition of milk, such as adjusting the fat content. Microfiltration and
ultrafiltration membranes can also be used to remove bacteria and spores
from milk for longer shelf life.
24. APPLICATION OF MEMBRANE
TECHNOLOGY IN FERMENTED
BEVERAGE
MEMBRANE
TECHNOLOGY
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Clarification: Microfiltration and ultrafiltration membranes are used to
remove yeast, bacteria, and other impurities from fermented beverages.
Concentration: Reverse osmosis and nanofiltration membranes are used
to concentrate fermented beverages by removing water.
Aroma recovery: Permeation through membrane is used to recover aroma
compounds from fermented beverages.
Fractionation: Nanofiltration and ultrafiltration membranes are used to
fractionate fermented beverages into different components, such as
separating different types of sugars or removing alcohol from beer.
Enzyme immobilization: Membrane technology is used to immobilize
enzymes in the production of fermented beverages, allowing for more
efficient and precise control of fermentation processes
25. APPLICATION OF MEMBRANE
TECHNOLOGY IN PROBIOTIC BEVERAGE
MEMBRANE
TECHNOLOGY
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Cell harvesting: Microfiltration membranes are used to harvest probiotic
cells, such as bacteria, from fermentation broth.
Clarification: Microfiltration and ultrafiltration membranes are used to
remove impurities and solid particles from probiotic beverages.
Concentration: Reverse osmosis and ultrafiltration membranes are
used to concentrate probiotic beverages by removing water.
Sterilization: Membrane filtration can be used as a sterilization method
to remove any remaining bacteria or other microorganisms in probiotic
beverages.
Encapsulation: Membrane technology is used to encapsulate and
protect probiotics, such as bacteria, during the production process and to
ensure their survival during storage and consumption.
26. EMERGING APPLICATION OF
MEMBRANE TECHNOLOGY
MEMBRANE
TECHNOLOGY
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1. Novel food processing techniques
Use of membranes in novel food processing techniques such as membrane
distillation, membrane emulsification, and membrane crystallization.
These techniques can improve food quality and create new products with unique
properties.
2. High-pressure membrane processes
Use of high-pressure membrane processes to reduce the use of heat and
chemicals in food processing
These processes can preserve the nutritional value and sensory properties of food
products while increasing efficiency.
3. Membrane-based sensors
Use of membrane-based sensors to detect foodborne pathogens and spoilage
indicators in real-time
These sensors can improve food safety and reduce food waste.
27. EMERGING APPLICATION OF
MEMBRANE TECHNOLOGY
MEMBRANE
TECHNOLOGY
2 7
4. Nano-filtration for food purification
Use of nano-filtration membranes to remove impurities and contaminants from food
and beverage products.
These membranes can produce high-quality, pure food products that meet the
highest industry standards.
5. Membrane-based separation and fractionation
Use of membranes to separate and fractionate components of food products such
as proteins, fats, and flavor compounds.
This can improve the nutritional value and sensory properties of food products and
create new functional ingredients.
6. Biopolymer membrane development
Development of new biopolymer membranes that are environmentally friendly and
biodegradable.
These membranes can replace traditional synthetic membranes and reduce
environmental impact.
