understanding the basics of membrane filtration chen 320 – group 7

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Lianne Monterroso Scott Shelton

Patricia Stratton Emily Wilborn

UNDERSTANDING THE BASICS OF

MEMBRANE FILTRATION

CHEN 320 – GROUP 7

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Introduction to Membrane Filtration

Pressure-Driven Membrane Separation

Membrane Materials, Structure, and Morphology

Membrane Format and Module Design MATLAB Code

Common Membrane Applications

Conclusion

ROADMAP

http://socialmediastrategiessummit.com/blog/a-roadmap-to-ensure-that-strategy-not-tactics-drives-your-social-media/roadmap/

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Accounts for 40% to 70% of capital and operating costs in the chemicals industry

Broad range of applications Process Water Treatment Wastewater treatment

and reuse Metal and catalyst

recovery Solvent recovery Gas separation Concentration of heat

sensitive biological macromolecules and proteins

INTRODUCTION TO MEMBRANE FILTRATION

http://cousemoses.wikispaces.com/Cubahttp://imperfectspirituality.com/2011/06/01/how-to-find-the-flow/flowing-waterfall/

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Membrane filtration can be accomplished with either dead end filtration or crossflow filtration.

Dead-end: Filter cake can form reducing filtration capacity.

Crossflow: Maintains more steady permeate flux and low pressure.

TWO MAIN TYPES OF FILTRATION

Figure: Created by Group 7

Figure: Created by Group 7

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PRESSURE-DRIVEN MEMBRANE SEPARATION

http://www.miniporeuf.com/channel.asp?id=26

• Reverse Osmosis

• Nanofiltration• Ultrafiltration• Microfiltration

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Employs tightest membranes for liquid separation. Only allows small water-soluble ions to go through

membrane along with water.

REVERSE OSMOSIS

www.degremont-technologies.com/dgtech.php?article458

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Removes multivalent ions and small molecules in nanometer range like sulfate ions, and sugars.

The most common type used for nanofiltration is the spiral membrane.

NANOFILTRATION

http://www.geaprocess.co.uk/gpuk/cmsdoc.nsf/webdoc/webb8uefdg

http://www.watertechtrading.com/purification-of-water/water-filtration/membrane-filtration/nano-filtration

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Used to retain relatively large dissolved materials like proteins and starches.

Ultrafiltration membranes are typically classified by their ability to retain component specific sizes.

ULTRAFILTRATION

http://www.answers.com/topic/reverse-osmosis

http://www.aquasource-membrane.com/-ultrafiltration-filtration-.html

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Suspended solids and large colloids are rejected, while dissolved solids and macromolecules pass through

Operate at low pressures of 10 psi or less.

MICROFILTRATION

http://www.geafiltration.com/library/enzyme_cell_separation.asp

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• Fabrication• Desired

Properties• Classification

s

MEMBRANE MATERIALS STRUCTURE AND

MORPHOLOGY

http://www.hidenisochema.com/application_industries/membrane-materials/

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Membranes are fabricated from variety of materials Made of Inorganic and organic materials Metals, polymers, and ceramics are used for different

applications based on their properties

FABRICATION OF MEMBRANES

http://icd.uni-stuttgart.de/?p=6947

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Ceramic and Metals used for aggressive media

Suitable for high temperature operations, acids, and strong solvent

CERAMICS AND METALS

http://www.made-in-china.com/showroom/ceramfil/product-detailNbcQIEdjLYhC/China-Ceramic-Membrane-Filter-CMF-Series-.html

http://www.directindustry.com/prod/purolator/stainless-steel-filter-cartridges-liquids-22202-884563.html

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Polymers are utilized most because of their price and versatility

Polymer membranes are typically made up of a thin layer of polymer on a porous backing, creating a material with high permeability, selectivity, mechanical strength, and chemical stability

POLYMERS

http://revision4gcses.wordpress.com/science/chemistry-2/polymers/

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Desired properties of membranes include:

High porosity Narrow pore size

distribution Sharp MWCO High mechanical strength Flexible High pH Chemical stability Surface properties Low fouling Low cost

DESIRED PROPERTIES

https://www.millipore.com/membrane/flx4/filter_properties_hm

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Membranes are classified according to structure, morphology, and application

Two classifications of membranes Symmetric membranes Asymmetric membranes

Composite membranes

CLASSIFICATION

http://research.che.tamu.edu/groups/Seminario/index-1.html

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Very few commercially available membranes are symmetric throughout their thickness

Some examples include: Polytetrafluoroethylene Polyethylene Polypropylene

SYMMETRIC MEMBRANES

http://ckj.oxfordjournals.org/content/3/suppl_1/i36/F2.expansion

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Include most of the commercially available membranes

Have either a thin microporous or dense permselective layer supported by a more-open porous substrate

The membrane may by integrally skinned, formed in a single operation, or by separate steps

An example of an asymmetric membrane is cellulose RO membrane, where both layers are made up of cellulose acetate.

ASYMMETRIC MEMBRANES

http://what-when-how.com/nanoscience-and-nanotechnology/nanofiltration-separations-part-1-nanotechnology/

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A composite membrane is a subset of asymmetric membranes

The skin layer and support layer are made up of different polymers based on the individual properties

The skin layer determines separation performance

Support layer determines mechanical stability

An example of a composite membrane is a polymide RO membrane which is made up of a thin polyamide permselective skin on a polysulfone UF support.

COMPOSITE MEMBRANES

http://www.ogj.com/articles/print/volume-94/issue-48/in-this-issue/production/membranes-solve-north-sea-waterflood-sulfate-problems.html

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• Cassette• Cartridge• Spiral

Wound

MEMBRANE MODULE DESIGN

Source: http://4.bp.blogspot.com/-Om7fiMFT42A/Tq4RXJWvfNI/AAAAAAAAFfg/RAxOua20zR8/s1600/2-12-idealfluidflow.008.png

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Cassette membranes are used for UF and MF.

The membrane filtrates the fluid, while the gaskets are used to separate the permeate, feed, and retentate streams.

Spacers introduce turbulence, which increases mixing and prevents the formation of a gel layer.

However, spacers are sometimes prone to particulate clogging, and can be difficult to clean.

CASSETTE

Source: "Understand the Basics of Membrane Filtration." Wang, Hua. Hongyi, Zhou. GE Global Research.

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INDUSTRIAL/LARGE-SCALE CASSETTE MODULE

Source: http://microclearmembrane.com/wp-content/themes/microclear_v0.1/img/products_photo_1.jpg

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Utilizes laminar flow for MF, UF, or NF.

Composed of a large number of hollow-fiber membranes in a cylindrical housing with permeate ports and end caps.

Has a very high packing density, therefore has a high surface area to volume ratio, making this particular filter ideal for product recovery.

CARTRIDGE

Source: "Understand the Basics of Membrane Filtration." Wang, Hua. Hongyi, Zhou. GE Global Research.

Source: http://ecx.images-amazon.com/images/I/41zayl%2BuLzL._SY300_.jpg

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Spiral Wound are used predominantly for RO.

They are composed of a multi-layered assemble of flat sheet membranes, and spacer screens.

These components are all rolled around a perforated tube, which seals the membrane and spacer layers on three sides.

SPIRAL WOUND

Source: "Understand the Basics of Membrane Filtration." Wang, Hua. Hongyi, Zhou. GE Global Research.

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They are built to have a high packing density by utilizing thin spacer screens.

Industrially, large-scale operations use these RO modules connected in parallel with one another.

SPIRAL WOUND MODULE USED FOR RO

Source: http://upload.wikimedia.org/wikipedia/commons/c/cf/Reverse_osmosis_membrane_coil.jpg

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>> % Rc: cake resistance >> % r: specific cake

resistance >> % Vs: volume of cake >> % Am: area of membrane >> >> %Plot of Rc vs. r (Vs =

0.001 m^3, Am = .01 m^2) >> r = linspace(0,10);>> Vs =

0.001;>> Am = .01; >> Rc = r*Vs/Am; >> plot(r,Rc,'-') >> legend('Vs and Am

constant') >> title('Plot of Rc vs. r') >> xlabel('r (m^-2)') >> ylabel('Rc (m^-1)')

PLOT OF CAKE RESISTANCE VS. SPECIFIC RESISTANCE WITH THE AREA OF THE MEMBRANE AND CAKE VOLUME HELD

CONSTANT

Figure: Created by Group 7

Source for Filtration equation: http://en.wikipedia.org/wiki/Microfiltration

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>> % Rc: cake resistance >> % r: specific cake resistance

>> % Vs: volume of cake >> % Am: area of membrane >> >> %Plot of Rc vs. Vs (r = 5 m^-2, Am = .01 m^2)

>> r = 5; >> Am = .01; >> Vs = linspace(1e-6,1,400); >> Rc = r*Vs/Am; >> plot(Vs,Rc,'-') >> legend('r and Am constant')

>> title('Plot of Rc vs. Vs') >> xlabel('Vs (m^-3)') >> ylabel('Rc (m^-1)')

PLOT OF CAKE RESISTANCE VS. CAKE VOLUME WITH THE AREA OF THE MEMBRANE AND SPECIFIC RESISTANCE HELD CONSTANT

Figure: Created by Group 7

Source for Filtration equation: http://en.wikipedia.org/wiki/Microfiltration

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>> % Rc: cake resistance >> % r: specific cake resistance

>> % Vs: volume of cake >> % Am: area of membrane >> >> %Plot of Rc vs. Am (r = 5 m^-2, Vs = .001 m^3)

>> Am = linspace(.0001,1,400);

>> r = 5;>> Vs = .001; >> Rc = r*Vs./Am; >> plot(Am,Rc) >> title('Plot of Rc vs Am') >> legend('r and Vs held constant')

>> xlabel('Am (m^2)') >> ylabel('Rc (m^-1)')

PLOT OF CAKE RESISTANCE VS. AREA OF THE MEMBRANE WITH THE SPECIFIC RESISTANCE

AND CAKE VOLUME HELD CONSTANT

Figure: Created by Group 7

Source for Filtration equation: http://en.wikipedia.org/wiki/Microfiltration

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•Desalinization using RO•Industrial water treatment•Biopharmaceutical manufacturing•Clarification steps in cellulosic ethanol production

COMMON MEMBRANE

APPLICATIONS

Picture: http://www.directindustry.com/prod/aqua-aerobic-systems-inc/membrane-bioreactors-mbr-wastewater-treatment-89335-876873.html

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Cost-effective Produce clean water from seawater in regions with limited

access to fresh water Removes salts, organic substances, algae, bacteria, and

suspended particles

DESALINATION FOR REVERSE OSMOSIS

Picture: "Understand the Basics of Membrane Filtration." Wang, Hua. Hongyi, Zhou. GE Global Research.

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Boiler feed water Cooling tower

water Process water in

many industries

INDUSTRIAL WATER TREATMENT

High purity water needed for:

Picture: http://en.wikipedia.org/wiki/Cooling_tower

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Conventional Treatment

MEMBRANE FILTRATION TECHNOLOGY MINIMIZES LAND, CONSTRUCTION, AND OPERATING COSTS:

Picture: "Understand the Basics of Membrane Filtration." Wang, Hua. Hongyi, Zhou. GE Global Research.

Membrane Treatment

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INDUSTRIAL MICROFILTRATION USES

Picture: http://bioprocessh2o.com/home/solutions/modular-containerized-mbr/

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For biological products: Recovery Purification Concentration

BIOPHARMACEUTICAL MANUFACTURING

Picture: "Understand the Basics of Membrane Filtration." Wang, Hua. Hongyi, Zhou. GE Global Research.

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Used for: Buffer exchange Final product

concentration Virus filtration

ULTRAFILTRATION

Picture: Created by Group 7

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CELLULOSIC ETHANOL PRODUCTION

Source: http://www.geafiltration.com/applications/membrane_filtration_ethanol.asp

Clarification of the pretreated liquor prior to hydrolysis

Clarification of the hydrolyzate stream prior to fermentation

Concentration fermentation pre-cursors

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CELLULOSIC ETHANOL PRODUCTION: CLARIFICATION USES

Picture: http://www.sciencedirect.com/science/article/pii/S0961953410003107

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Membrane filtration has lots of applications!

Several types of driving forces for membrane filtration: Pressure Difference Concentration Difference Temperature Difference

Used in many industrial processes: Desalination Wastewater and process water

treatment Biopharmaceutical

applications

CONCLUSION

Different types of membranes can be applied to various applications based on particle size: Reverse Osmosis (Smallest

constituent) Nanofiltration Ultrafiltration Microfiltration (Largest

constituent)

http://en.wikipedia.org/wiki/Filtration

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• Add a chemical to the solution being filtered to make membrane more durable

• Combine multiple driving forces

• Introduce turbulent flow to prevent clotting

SUGGESTED WORK FOR IMPROVEMENTS

http://ezial.com.au/Systems/SystemImprovements/tabid/115/language/en-GB/Default.aspx