ULTRAFILTRATION – a membrane separation...
Transcript of ULTRAFILTRATION – a membrane separation...
ULTRAFILTRATION
A MEMBRANE SEPARATION TECHNIQUE
NAGARAJU M
Ph.D. Scholar
Dept. of PHP&FE
CAE, Jabalpur (M.P.)
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OUTLINE
Membrane separation techniques
Filtration spectrum
Modes of filtration
Ultrafiltration
Membrane configurations
Applications of ultrafiltration
Case study
Membrane fouling
Conclusion
References
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MEMBRANE SEPARATION TECHNIQUES
Membrane separation is a technology which
selectively separates (fractionates) materials via pores
and/or minute gaps in the molecular arrangement of a
continuous structure
Separation process is purely physical
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MEMBRANE SEPARATIONS
Pressure driven
• RO, NF, UF, MF, Gas separation, Pervaporation
Thermal driven
• Membrane distillation
Concentration driven
• Dialysis
Voltage/Charge driven
• Electro dialysis 4
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CHARACTERISTICS OF PRESSURE DRIVEN
MEMBRANE PROCESSES
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Process
technology
Typical operating
pressure (bar)
Feed recovery (%) Rejected species
MF 0.5-2 90-99.99 Bacteria, cysts, spores
UF 1-5 80-98 Proteins, viruses, endotoxins
NF 3-15 50-95 Sugars, pesticides
RO 10-60 30-90 Salts, sugars
ADVANTAGES OF MEMBRANE PROCESSES
Energy efficient by virtue of ambient temperature
operation
No phase change
Physical separation of compounds
Low capital & operating costs
Simplicity of operation and therefore minimum training
requirement to operators
Availability of different configurations
Modular in nature-over a wide range of capacities can
easily be fabricated
Short start-up and shut down times
Minimum of moving parts
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APPLICATIONS OF MEMBRANE TECHNIQUES IN
FOOD SECTOR Food sector Membrane separation
technique
Purpose
Reference
Fruit and
Vegetable
Juices
MF or UF
MF and RO
Clarification
Fruit juice concentrates
Todisco et al.,
1998
Sugar Juices MF or UF Clarification Herve, 1994
Cane Sugar
Refinery
NF Separate colourings and salts Kwok, 1996
Vegetable
Proteins
UF and diafiltration High protein yield Be´rot et al., 1998
Brewing
Sector
MF mash separation, clarification of
rough beer
Fillaudeau, 1999
Wine Making MF
Electrodialysis
Microbiological stability
Tartaric stability
Daufin et al., 2001
Milk and Dairy
Industry
RO
MF
NF
Whey concentration
Globular milk fat fractionation,
protein extraction process
Whey protein valorization
Le et al., 2014 8
FILTRATION MODES
Full feed supply passes directly
through the filter. These filters
require periodic cleaning (or
back washing) of membranes
Requires less energy
Membrane fouling predominant
Employs a high velocity of feed
flowing in parallel over the
membrane surface
Higher filtration rates by
reducing membrane fouling
Direct Flow Mode Cross Flow Mode
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ULTRAFILTRATION
Pressure driven membrane filtration technique for
concentration, fractionation and purification of
macromolecules in solutions without phase change or
addition of chemicals or solvents
Principle of sieving on a molecular level
Low applied pressures are sufficient to achieve high
flux rates
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ULTRAFILTRATION
The pore size and molecular weight cut-off (MWCO) are
used to characterize a membrane
The MWCO of ultrafiltration membranes ranges between
1-1000 kDa
Transport of solutes through ultrafiltration membranes
depends on:
1) pore size of the membrane
2) interactions between UF feed components and membrane
matrix
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PRINCIPLE
Pressure induced separation of solutes from a solvent through a semi permeable membrane
The relationship between the applied pressure on the solution to be separated and the flux through the membrane is described by the Darcy equation:
J: flux (flow rate per membrane area)
TMP: Trans membrane pressure (pressure difference between feed and permeate stream)
μ: solvent viscosity
Rt: total resistance (sum of membrane and fouling resistance)
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FACTORS AFFECTING THE PERFORMANCE OF
ULTRAFILTRATION
Flow velocity
Critical for liquids containing emulsions or suspensions
Higher flow velocity reduces the fouling
Operating pressure
Permeate rate is directly proportional to the applied pressure
Operating temperature
Permeate rates increase with increasing temperature
Flow type
Dead end configurations: batch processes with low suspended solids
Cross flow configurations: continuous operations 14
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UF membrane materials
Polymers
Polyvinylidiene fluoride (PVDF)
Polyether sulfone (PES)
Polysulfone (PS)
Polyacrylonitrile (PAN)
Polyethylene (PE)
Polypropylene (PP)
Polyvinyl chloride (PVC)
Ceramic membranes
UF membrane expected properties
Mechanical strength
Hydrophilicity
Durability
Chemical stability
Low polymer cost
Current standards (> 85% solutions)
PVDF
Chemical stability
Mechanical strength
Durability
PES
Hydrophilicity
Low polymer cost
History (early ‘90s)
UF MEMBRANE CONFIGURATIONS
Hollow fibre
Tubular
Spiral wound
plate and frame
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UF applications
Water treatment
Waste water treatment and reclamation
Food processing
industry
Biotech and Pharmaceutical
Industries
Purification and concentration of products
Automobile industry
Egg-white concentration
Textile industry
Paper and pulp industry
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UF IN FOOD INDUSTRY
Recovery of whey protein and concentration of skim
milk in dairy industry
Clarification and bacteria removal of wine
Recover valuable products from soya whey and other
dilute waste streams
Purification of fermentation solution, and clarification
and concentration of fruit juice
Concentration of gelatin
Recovery of sugar from sugary water
Fractionation and concentration of egg albumin,
proteins, extracts such as vanilla, lemon, peel extract,
etc., and animal, fish and vegetable oils 19
CASE STUDY
Concentration of lycopene in the pulp of
papaya(Carica papaya L.) by ultrafiltration on a pilot
scale
Juliana et al., 2015
Objective: To evaluate the performance of two
polymeric membranes (polysulfone 100 kDa and
polyethersulfone 50 kDa) in the concentration of
lycopene of papaya pulp (Carica papaya L.) by
ultrafiltration on a pilot scale
Food and bioproducts processing, 9 (6):296–305
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MATERIALS AND METHODS
Raw material
Whole papaya pulp (soluble solids11.5 Brix), pasteurized and frozen
Equipment
Membranes
PES50, made of polyethersulfone with a molecular weight cutoff of 50 kDa
PS 100, made of polysulfone, with a molecular weight cutoff 100 kDa 21
FT: feed tank
V: valve
LP: lobe pump
MFM: magnetic flow meter
MN: manometer
MB: membrane
TE: thermometer
MV: micrometric valve
BP: Becker to permeate
B: Balance
Effect of enzymatic treatment on the raw material in the papaya pulp
ultrafiltration
Pectinase (Pectinex Ultra SP-L)
Pectinase 0.1% of initial volume of papaya pulp
constant manual stirring at 35°C for 60 min.
Pulp heated to 50°C
UF: 1 bar pressure and velocity 3 m s−1.
pH, total solids and lycopene of the permeate and retentate, carotenoids
retention rate in the retentate, final permeate flux, and total ultrafiltration time
were statistically analyzed using ANOVA and Tukey test(p = 0.05)
Effect of operational conditions in the concentration of lycopene by
ultrafiltration using the membrane PS 100 and PES 50
Operational pressure1 or 2 bar and tangential velocity 3 or 6 m s−1 for PS 100
Operating pressure 0.8, 1.5 or 3 bar for PES 50 22
Physicochemical analysis
Papaya pulp, retentate and permeate, were analyzed on:
total carotenoids, total solids and pH
Permeate flux (J), concentration factor (CF) and
retention index (R%)
mp: mass of the permeate in time t
AP: permeation area of the membrane
ma: mass of the feed
mr: mass of the retentate
Cp and CR: concentrations of the component of interest in
the permeate and the retentate
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RESULTS AND DISCUSSION
Effect of enzymatic treatment on the raw material in the ultrafiltration of the
papaya pulp
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Table 1 – Average values of the results obtained in the ultrafiltration of papaya pulp (Carica papaya L.) at the
different conditions. (A) CF = 1.65,using polymeric membrane PS100, with or without enzymatic treatment of the
raw material, v = 3m s−1, p = 1 bar. (B) CF = 1.50, using polymeric membrane PES50, v = 6 m s−1 and p = 3.0,
1.5 or 0.8 bar.
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Total solids (a) and lycopene (b) contents of the retentate and the permeate obtained in the UF of papaya pulp (Carica papaya
L.) at 50°C using polymeric membrane PS 100 as a function of pressure and operating velocity
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Lycopene retention index (a), final permeate flux (b) and total time of ultrafiltration (c) obtained in the UF of papaya pulp
(Carica papaya L.) at 50°C using polymeric membrane PS 100 as a function of pressure and operating velocity
CONCLUSION
UF processes resulted in retention of more than 98% of
the lycopene
Enzymatic treatment of the raw material, in the
conditions studied, had no significant effect on the
permeate flux
The best UF performance was obtained with the
polysulfone membrane with a molecular weight cutoff of
100 kDa, pressure 1 bar and tangential velocity 6 m s−1
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Study Findings Reference
Fruit juices UF membrane is able to retain large particles such
as microorganism, lipids, protein and colloids; and
the small particles, for example vitamins, salts,
and sugars, are well reserved in juice
Cassano, et al.,
2007
Korla pear
juice
TSS, total sugar, pH and TA of UF pre-treated
korla pear juice were no significant change
compared to raw juice (P > 0.05)
After UF, total phenols and ascorbic acid were
decreased. Decrease of total phenols was due
to UF retention of compounds with large
molecular weight, such as self-conjugated
phenols and the bounded phenols with other
compounds. Loss of ascorbic acid was due to the
exposure to light and oxygen during the feed liquid
circulation of UF treatment
main aroma compounds in UF pre-treated juice
showed no significant change compared to raw
korla pear juice (P > 0.05)
Zhao et al, 2016
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Reviews regarding applications of UF in food sector
Study Findings Reference
Membrane
fouling
The physical strategies for fouling reduction include the
use of turbulence generating devices, sonication,
centrifuge and use of electric and magnetic fields
Vardanega
et al., 2013
Date palm
sap syrups
UF process affects significantly the sap syrup
composition. Retention of sucrose through tubular
membranes caused a decrease in its content in sap
permeate and also in the corresponding syrups, and a
richness in reducing sugars. This contributes to a
reduction of the syrup crystallization phenomenon
Ines et al.,
2016
Protein
separation
Two proteins with a close molecular weight such as
the hemoglobin (64677 Da) and bovine serum albumin
(66430 Da) can also effectively separated by stacking
flat ultrafiltration with same membranes
Feins &
Sirkar, 2005
Separation
of alpha-
chain
subunits
from tilapia
skin gelatin
α1-subunit was effectively separated by a two-step
ultrafiltration process combined a single 100 kDa
MWCO RC membrane and a sandwich configuration of
same membranes. The α2-subunit was also separated
by the same ultrafiltration process with 150 kDa MWCO
PES membranes
Shulin et al,
2015
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Study Findings Reference
Cheese
making
Membrane technology is practical for handling a
considerably large amount of production (1–2 kg of cheese
yields 8–9 kg of whey), and it is able to separate protein,
lactose, salt and water from cheese whey. In industry,
ultrafiltration is widely used to concentrate whey protein
because it can exclude impurities to some extent
Baldasso et
al., 2011
Soy
protein
isolate
The combination of the Jet Cooking and the enzyme-
assisted UF treatments are able to effectively reduce the
anti-nutritional factors found in the soy products. This
processing strategy offers a strong potential for application
in the production of soy protein products for use in infant
formulas
Yang et al.,
2014
Honey Ultra filtration improves the quality of honey and provides
honey as a safe ingredient in food processing
Itoh et al.,
1999
fish meal
effluents
UF is a promising separation process for the recovery and
concentration of proteins from fish meal effluents
Afonso et al.,
2004
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MEMBRANE FOULING
Fouling refers to the irreversible alteration in
membrane properties, resulting from several
interactions of feed stream components and
membrane (Saxena et al., 2009)
In food application, membrane is usually fouled by
biofoulants such as protein and polysaccharide
(Tsagaraki & Lazarides, 2011)
Membrane fouling results in substantial flux decline
and increase of plant maintenance and operating costs
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MECHANISMS OF MEMBRANE FOULING BY
PROTEIN SUSPENSIONS
The phenomenon of concentration polarization
followed by the formation of a gel layer (Porter,
1972)
Adsorption of solutes on the membrane surface and
inside the pore structure (Aimar et al., 1986)
Deposition and pore blocking of protein aggregates
due to denaturation (Martine et al., 1991)
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MEMBRANE FOULING
Bio-fouling
Organic fouling
Inorganic fouling
Particulate fouling
Pretreatment
(pre-filtration, dispersants,
anti-scalants etc.)
Membrane/module
(membrane surface
modification,
spacer/channel design)
Operation
(cleaning, recovery)
Categories
Control
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TECHNICAL & SCIENTIFIC CHALLENGES
Membrane
Fouling…
Membrane
Integrity…
Trace Organics
Rejection…
Module Design… 34
CONCLUSIONS
Membrane filtration processes are gaining more
attention and focus in food industry due to its
advantages (environmental friendliness, cost saving,
and product improvement) as compared with other
conventional methods
Ultrafiltration becomes an essential part in food
technology as a tool for separation and concentration
Fouling is the major problem in UF and various studies
are being conducted to improve ultrafiltration, focusing
on membrane fouling control and cleaning of fouled
membranes 35
REFERENCES Afonso, M. D., Ferrer, J. and Bo´ rquez, R., 2004. An economic
assessment of proteins recovery from fish meal effluents by ultrafiltration. Trends in Food Science & Technology. 15: 506–512.
Aimar, P., Baklouti, S. and Sanchez, V., 1986. Membrane–solute interactions: influence on pure solvent transfer during ultrafiltration. Journal of Membrane Science, 29(2): 207–224.
Baldasso, C., Barros, T. C. and Tessaro, I. C. 2011. Concentration and purification of whey proteins by ultrafiltration. Desalination, 278(1–3): 381–386.
Be´rot, S., Nau, F., Thapon, J.-L., Que´meneur, F., Jaouen, P. and Vandanjon, L., 1998, Vegetal and animal proteins, Membrane separations in the Processes of the Food Industry, G. DauŽ n, F. Rene´, P. Aimar (Eds.) (Lavoisier Tech and Doc, Paris France), pp. 373–417.
Daufin, G., Escudier, J.P., Carrère, H., Bérot, S., Fillaudeau, L. and Decloux, M., 2001. Recent and emerging applications of membrane processes in the food and dairy industry. Food and Bioproducts Processing. 79(2):89-102.
Feins, M. and Sirkar, K. K., 2005. Novel internally staged ultrafiltration for protein purification. Journal of Membrane Science, 248(1): 137–148.
Fillaudeau, L., 1999. Cross-•flow microŽ filtration in the brewing industry— An overview of uses and applications, Brewer’s Guardian, 128(7): 22–30.
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Herve´, D., 1994, Production de sucre rafŽ ne´ en sucrerie de canne, Industries Alimentaires et Agricoles, 111(7/8): 429–431.
Ines. M., Samia, B., Abir, M., Sabine, D., Hamadi, A., Christophe, B., Souhail, B. and Manel M. 2016. Effect of ultrafiltration process on physico-chemical, rheological, microstructure and thermal properties of syrups from male and female date palm saps. Food Chemistry. 203: 175–182.
Itoh, S., Yoshioka, K., Terakawa, M., Sekiguchi, Y., Kokubo, K. and Watanabe, A., 1999. The use of ultrafiltration membrane treated honey in food processing. Journal of the Japanese Society for Food Science and Technology. 46(5): 293-301.
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Saxena, A., Tripathi, B. P., Kumar, M. and Shahi, V. K., 2009. Membrane-based techniques for the separation and purification of proteins: an overview. Advances in Colloid and Interface Science, 145(1–2): 1–22.
Shulin, C., Lanlan, T., Wenjin, S., Wuyin, W., Kazufumi, O. and Munehiko, T., 2015. Separation and characterization of alpha-chain subunits from tilapia (Tilapia zillii) skin gelatin using ultrafiltration. Food Chemistry.188: 350–356.
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Vardanega, R., Tres, M.V., Mazutti, M.A., Treichel, H., De Oliveira, D., Di Luccio, M. and Oliveira, J.V., 2013. Effect of magnetic field on the ultrafiltration of bovine serum albumin. Bioprocess Biosyst. Eng. 36 (8): 1087–1093.
Yang, j., Jian, G., Xiao-Quan, Y., Na-Na Wuc, Jin-Bo, Z., Jun-Jie, H., Yuan-Yuan, Z. and Wu-Kai, X. 2014. A novel soy protein isolate prepared from soy protein concentrate using jet-cooking combined with enzyme-assisted ultra-filtration. Journal of Food Engineering. 143: 25–32
Zhao, L., Yongtao, W., Xiaotong, H., Zhijian, S. and Xiaojun, L., 2016. Korla pear juice treated by ultrafiltration followed by high pressure processing or high temperature short time. LWT - Food Science and Technology. 65: 283-289
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