Prof. (Neal) Chung Tai-Shung

1981 Ph.D State U. of New York at Buffalo1980-1993 Hoechst Celanese, New Jersey (now is Celanese, Ticona and Aventis)

1993-1995 Aeroquip, MichiganJuly 23, 1995 NUS

1996-2001, Joint appointments in IMRE (Institute of Materials Research and Engineering) as Program Coordinator, Program Manager, Program Director, IMRE Deputy Director

1999-2000, consultant for Air Products (USA)2004-2007, senior consultant for Hyflux (Singapore)

2007-2010, fellow, Singapore - MIT alliance2008, consultant for Norit (the Netherland); 2010, for HTI (USA)

2008-2012, visiting chair professor, Chung Yuan Christian U, Taiwan 2010-2015, visiting honorary professor, Central South U, Hunan, China

2011-2013 Provost’ Chair Professor, NUS2012, Fellow (Academician), the Academy of Engineering Singapore

E-mail: chencts@nus.edu.sg & Websites:1) http://www.chee.nus.edu.sg/people/faculty_chungneal.html

2) http://www.chbe.nus.edu.sg/membrane

Membrane Science and TechnologyCN5251 and CN6251

Objectives1. Understand the fundamentals of membrane science and

engineering

2. Familiar with state of the art membrane technologies and their applications to solve problems in this complicated and rapidly changing world

3. To be a knowledgeable students on membrane materials and hollow fiber membrane process

4. Become creative with confidence in your career, membrane research, PG study, and future business development

Inaugural ceremony for the appointment of Prof. Chung as Provost's Chair Professor on May 26, 2011

IES (Institution of Engineers Singapore) Prestigious Engineering Achievement Award 2010 on 4 September 2010

• http://newshub.nus.edu.sg/headlines/0910/neal_06Sep10.php

IChemE (Institute of Chemical Engineers, UK) in Singapore Awards for Excellence and Innovation 2010 in Sustainable Technology (March 24, 2010)

http://newshub.nus.edu.sg/headlines/0410/icheme_06Apr10.phphttp://www.eng.nus.edu.sg/ero/announcement/web-neal03-10.pdf

http://cms.icheme.org/mainwebsite/general-barafc3d75d.aspx?map=7c0c5d8c23c21921bc19dc2bd35fb645

AWARD WINNERS WITH ICHEME DIGNITARIES: (from left) NUS Prof Chung Tai-Shung, MSD Manager of Engineering Projects Mr Tajinder Singh Rana, IChemE Fellow Mr Edwin Khew, Chairman of IChemE in Singapore Dr Keith Carpenter, Senoko Energy CEO & President Mr Brendan Wauters, Singapore Polytechnic Senior Lecturers Mr Tay Kheng Siong and Ms Phua Siew Teng

Prof. Chung and his wife Ivy

Hyflux-SNIC (Singapore NationalInstitute of Chemistry) Award in Environmental Chemistry

(19 March 2010)http://www.eng.nus.edu.sg/ero/announcement/web-neal03-10.pdf

http://www.chee.nus.edu.sg/highlights/highlight-profChung-hyflux-snic-2010-03.html

1. Expert and known in membrane science, separation and polymers. 2. Editorial Board Members

3. A part of the team developed and commercialized Vectra™liquid crystalline polymers with the annual business size of US$150 million.

4. Co-inventor of Kristal™ 600 series at Hyflux.5. An inventor of > 50 patents (including 37 US patents), one of

the highest patent holders in NUS.6. One of most highly cited NUS professors (citation >8700)7. H-Index: 45 (from 1990-now)

1) Journal of Membrane Science (Impact Factor = 3.85 in 2011) http://www.elsevier.com/wps/find/journaleditorialboard.cws_home/502692/editorialboard

2) Chemical Engineering Journal (Impact Factor = 3.461 in 2011)http://www.elsevier.com/wps/find/journaleditorialboard.cws_home/601273/editorialboard

3) Separation and Purification Reviews (Impact Factor = 2.615 in 2011)http://taylorandfrancis.co.uk/journals/journal.asp?issn=1542-2119&linktype=5

4) Desalination (Impact Factor = 2.590 in 2011)http://www.elsevier.com/wps/find/journaleditorialboard.cws_home/502683/editorialboard

5) AIChE Journal (Impact Factor = 2.261 in 2011) (from Aug 2012)6) Industrial & Engineering Chemistry Research (Impact Factor = 2.237 in 2011)

http://pubs.acs.org/userimages/ContentEditor/1233861021334/iecred-eab.pdf7) Chemical Engineering Research and Design (ChERD) (Impact Factor = 1.968 in 2011)

http://www.elsevier.com/wps/find/journaleditorsbiography.authors/713871/editorbiography8) Chemical Engineering and Technology (Impact Factor = 1.598 in 2011)

http://www3.interscience.wiley.com/journal/10008333/home/2044_edbd.html9) Polymer Engineering and Science (Impact Factor = 1.302 in 2011)

http://www3.interscience.wiley.com/journal/107639236/home/EditorialBoard.html10) Journal of Applied Polymer Science (Impact Factor = 1.289 in 2011)

http://www3.interscience.wiley.com/journal/30035/home/EditorialBoard.html11) Separation Science and Technology (Impact Factor = 1.088 in 2011)

http://www.informaworld.com/smpp/title~db=all~content=t713708471~tab=editorialboard12) Chinese Journal of Chemical Engineering (CJChE) (Impact Factor = 0.826 in 2011)

http://www.elsevier.com/wps/find/journaleditorialboard.cws_home/707628/editorialboard14) Recent Patents on Engineering (Bentham Science Publisher)

http://www.bentham.org/eng/EBM.htm15) Current Opinion in Chemical Engineering

http://www.elsevier.com/wps/find/journaleditorialboard.cws_home/725837/editorialboard16) Polish Journal of Chemical Technology

http://versita.com/pjct/editors/

Journal of Membrane Science (Impact Fact = 3.850)

Publication number in Journal of Membrane Science (JMS) (Total: 10,459) 9 April 2012

Chung132 Wessling

117Noble

89 Lai86

Matsuura96

Fane118

Koros80

Paul54

Cussler53

Drioli70

Zydney55

1 2 10 10 1110543 76 8 9

Sirkar54

Freeman54

Prof. Chung joined NUS in 1995 and has the shortest academic career in this table (16 years)

Except Prof. Wessling, Prof. Zydney AND Prof. Freeman, all others are older than Prof. Chung

Synthesis Field Tests

MaterialCharacterization

Hollow Fiber and Module Fabrication & Characterization

System Design & Processing Simulation

Methodologies to Develop Hollow Fiber Membrane Capabilities and Technology

Overview of My Previous Work (1980-1982)

Research Focuses in Celanese Engineering Resins Company:

• Mathematic simulation of injection molding process

• Stretch blow molding for PET bottles (starting my experience and understanding on membranes)

Representative Papers:

• T. S. Chung, Principles of Preform Design for Stretch Blow Molding Process, Polymer-Plastics Technology and Engineering, 20, 147 (1983).

• T. S. Chung and Y. Ide, An Analysis of Packing Stage in Injection Molding of Disk Cavities, J. Applied Polymer Science, 28, 2999 (1983).

• T. S. Chung, The Effect of Diffusion on the Inflation of a Spherical Viscoelastic Film, Chemical Engineering Science, 40, 1608 (1985).

• T. S. Chung, Pressure Build-up During the Packing Stage of Injection Molding; Polymer Engineering and Science, 25, 772 (1985).

• Liquid crystalline polymers/carbon fiber prepreg and composites for aerospace applications

• Fundamental understanding of injection molding and fiber spinning processes (starting my experience and knowledge on the fabrication of fibers and hollow fibers)

Representative Papers :• T. S. Chung, Isothermal Steady Spinning of an Oldroyd Fluid B, AlChE J., 31, 857

(1985).

• T. S. Chung, Z. Gurion, and J. B. Stamatoff, Induced Orientational Behavior of Liquid Crystal Polymer by Carbon Fibers, Polymer Composites, 6, 181 (1985).

• T. S. Chung and P. E. McMahon, Liquid Crystal Polyester/Carbon Fiber Composites, J. of Applied Polymer Science, 31, 965 (1986).

• T. S. Chung, Analysis of Pressure Increase During the Injection Mold Packing; Industrial and Engineering Chemistry Research, 26, 161 (1987).

• US Patents: 4,588,538 (May 1986), 4,734,240 (March 1988), 4,799,985 (January 1989), 4,818,318 (April 1989) US 4,871,491 (October 1989)

Research Focuses in Celanese Engineering Resins Company (1983-1985)

• Basic research on Vectra™ liquid crystal polymers

• Fundamental understanding of optical data storage process (starting my understanding on the importance of barrier materials and the effect of O2 and water diffusion and sorption)

Representative Papers :

• T. S. Chung, Product of Ultra-High Modulus Liquid Crystal Polymeric Rods; J. of Polymer Science, Physics, 26, 1549 (1988).

• T. S. Chung, G. W. Calundann, and A. J. East, Liquid-Crystalline Polymers and Their Applications Encyclopedia of Engineering Materials, Marcel Dekker Publisher, Vol. 2, 625 (1989).

• T. S. Chung, Pit Formation during Laser Marking of Thin Organic Films, J. of Applied Physics, 60, 55 (1986).

• T. S. Chung, Laser-Induced Fluid Motion on a Dye/Polymer Layer for Optical Data Storage, AlChE J., 33, 1041 (1987).

Research Focuses in Hoechst Celanese Research Division (1986-1988)

Bullet proof vest

• Developed and commercialized Vectra™ liquid crystal polymers

• Membrane separators for lithium rechargeable battery

• Kidney dialysis membranes based on Cellulose acetate

Representative Papers :• T. S. Chung, The Recent Developments of Thermotropic Liquid Crystalline

Polymers, Polymer Engineering and Science, 26, 901 (1986).

• T. S. Chung, G. W. Calundann, and A. J. East, Liquid-Crystalline Polymers and Their Applications Encyclopedia of Engineering Materials, Marcel Dekker Publisher, Vol. 2, 625 (1989).

• T. S. Chung, P. Foley and E. R. Kafchinski, Development of Polyethylene Tetrafluoroethylene Microporous Film for Advanced Batteries, J. of Material Science, Electronics. 4, 259 (1993).

• US Patents: 4,910,106 (March 1990), 4,997,603 (March 1991), 5,043,113 (August 1991).

LCP as computer connectors

Research Focuses in Hoechst Celanese Research Division (1988-1990)

• Polymer blends, high performance polymers

• Fundamental understanding of gas separation membranes

Representative Papers :• T. S. Chung and F. K. Herold, High-modulus Polyaramide and

Polybenzimidazole Blend Fibers, Polymer Engineering and Science, 31, 1950 (1991).

• T. S. Chung, et al., Fluoro-Containing Polyimide Blends: Prediction and Experiments, J. Polymer Science, Chemistry, 29, 1207 (1991).

• T. S. Chung, et al., Development of Polyethylene Tetrafluoroethylene Microporous Film for Advanced Batteries, J. Material Science, Electronics. 4, 259 (1993).

• T. S. Chung, et al., Development of A Defect-free 6FDA-Durene Asymmetric Hollow Fiber and Its Composite Hollow Fibers, J. Membrane Science, 88, 21 (1994).

• US Patents: 4,997,603 (March 1991), 5,043,113 (August 1991), 5,110,879 (May 1992), 5,209,883 (May 1993), 5,413,852(May 1995), 5,490,931 (February 1996).

Research Focuses in Hoechst Celanese Research Division (1991-1993)

Four Major Issues on Earth

Lower pharmaceutical and medical costsArtificial organs and many others

Affordable healthcare

4

New energy (biofuel, biogas, battery, fuel cell)Produce energy with higher purity

Energy 2

Capture CO2 (pre-combustion or post-combustion)Produce cleaner energy (H2, CH4, fuel cell)

Global warming3

Develop water reuse technologiesLow-cost desalination technologies

Clean water shortage

1

Potential ways to overcome these issuesIssues

Membrane R & D in the last 16 years at NUS

Mature Business Growth Business Embryonic BusinessO2/N2 , H2/N2

Separation(NUS, A-Star, Mitsui Chemicals)

CO2/CH4 Separation (BG, UOP, Mitsui Chemicals,

NRF)

H2/CO2 Separation (NRF)CO2 capture (A-Star)

Biofuel separation(A-Star, Mitsui Chemicals, PBI)

Carbon membranes C2-C4 Separation

(Mitsui Chemicals, NUS, NRF)

Osmotic power(NRF/EWI/PUB) + Dow?

UF/MF (Hyflux)

Membrane bioreactor(Hyflux)

Nano-filtration (NUS, GSK, China Gansu)

Forward osmosis(NUS, Saudi KAUST, Eastman Chemicals, BASF, NRF/EWI)

Biomimetic membranes (NRF/EWI)

Membrane distillation (A-Star)

Kidney dialysis(BASF)

Pervaporation(A-Star, Merck, Mitsui Chemicals,

GSK)

Pharmaceutics Separation (NUS, GSK)

Membranes for protein, isomers, and chiral separation

(NUS, A-Star, SMA)

Green: water related researchRed: energy relatedPurple: life science related

Grants > S$48 millions have been received in 16 years($7 millions from industries and overseas Institutes)

16

1. As a Christian, I thank God for the provision of many good PhD students (12-15), good staff (10-12 Post-doctors, 15-20 Research Assistants, 4 Lab Officers), and plenty of research funds (> S$48 millions US$38 millions).

2. Thank British Gas (UK), UOP (USA), Merck (USA), Mitsui (Japan), Hyflux (Singapore), BASF (Germany), KAUST (Saudi Arabia), PBI (USA), Eastman Chemicals (USA), GSK (USA), Singapore’s A-Star, NRF, EWI, PUB, and NUS for funding my membrane research during the last 16 years.

Acknowledgement

Team members (March 13 2010)

Water recycle and production

Global warmingEnergy

Affordable healthcare

1. Batteries & fuel cell2. High purity CH4, H2,

production3. Concentrate biofuel,

biogas

1. Capture CO2 from flue gas and power plants

2. Capture other green house gases

1. Artificial kidney, skins, and lungs2. Control release for drug delivery3. Purification and separation of proteins4. Chiral drug separation5. Pharmaceutical and medicine purification

1. Micro-filtration (MF), ultra-filtration (UF) and nano-filtration (NF) membranes, membrane bioreactor (MBR) for water reuse

2. Reverse osmosis (RO) membranes, forward osmosis (FO) and membrane distillation (MD) for seawater desalination

Membrane Technologies

Risks and Rewards in Membrane R & D

Price per ft2

membrane area

Degree of difficulties, Market entering barrier, Risks

Commodity products

High value-added productsEnergy, Biofuel,

Chemicals, CO2Capture

Pharmaceutical, Biomedical and

Life Science

$10

$100

US $1

$1000

Specialty products

Water and EV related

3 Key Elements to Determine the Performance (flux & selectivity) and Applications of a Membrane

1. Pore Size Depending on pore size, membranes can be used for gas and liquid separations

• 0.3-0.5 nm for gas separation and pervaporation• 0.4-1.2 nm for desalination, separate low Mw solutes• 2-200 nm for ultra-filtration, separate high Mw solutes • 50-1000 nm for micro-filtration, remove bacteria, solids

2. Material Chemistry• Determines the spinnability and mechanical strengths• Inherent hydrophilicity / hydrophobicity, fouling tendency• Intrinsic permeability & selectivity for gas separation • Bio-compatibility for bio-membranes • Chemical resistance for harsh environments

3. The Selective Layer Thickness• Controls the flux (productivity)• As thin as possible• The substructure provides the mechanical support but with

minimal transport resistance

The selective layer

NUS is the world leader on Hollow Fiber Spinning and Formation

Bore-fluid

Air-gap Region

Die swell

Coagulation Bath

dope

MoistureStretch

solvent vaporization

Capillary flow

Spinneret(hot)

Internal coagulation

External coagulation

NUS spinning facilities

The effects of spinneret design on membrane formation and performance

Spinnerets Parameters

Flow angels:  60 o, 75 o, 90 o

L = 4 mm

Ri = 0.25 mm

D = 0.3 mm

Pressure outlet

Z

rFlow Angle

Velocity inlet

Dope solution

L

R=0.5· DRi

enlarge

The World Leader on Dual-Layer Spinneret and spinning

Concentricity & uniformity of both layers

Membrane formation for flat asymmetric membranes and hollow fiber membranes

undesirable desirable sponge-like structure

P84-original 1μm 100nm 100nm

CrossCross--sectionsection SurfaceSurfaceEnlarged crossEnlarged cross--sectionsection

Flat

Hollow fiber

The cross-section of the wet-spun hollow fibers (0 cm air gap)

A) ΔD = 0.10 mm C) ΔD = 0.25 mm

D) ΔD = 0.35 mm E) ΔD = 0.50 mm

B) ΔD = 0.175 mm

Scale bar : 200 mWidjojo and Chung

Ind. Eng. Chem. Res. (2006)

Macrovoid - free

0

10

20

30

40

50

60

70

80

90

100

Hollow Fiber Membranes in All Journals (4,538) in 2010Chung98

Sirkar76 Saito

66 Sugo64

Li64

1

Semmense43

Sakai41 Teo

37Koros33

Sugita33

Matsuura30

Tan33 Wang

28Wessling

29

2 43 4 6 7 98 9 9 1312 14

0

10

20

30

40

50

60

Chung56

Sirkar33 Li

28Cussler21

Wang22

Sugo20

Saito20

Wessling18 Teo

15Koros14

1 82 3 4 5 6 6 109

Hollow Fiber Membranes in Journal of Membrane Science (833)in 2010

Flat-sheet asymmetric membranes

Membranes for Water Reuse and Desalination

Water Reuse and Desalination

http://whyfiles.org/131fresh_water/2.html

Global 2030 needs

2x Electricity

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

2008 2010 2015 2020 2025 2030

Emerging

Developed

(Billions of kW hours)

19.9

U.S.

0

5

10

15

20

Saudi

Arabia

Algeria

Korea

France

Spain

India

Japa

nRus

siaChin

a

50.2

62.2

Brazil

*at same consumption rate

3x Water(In billion cubic meters)

This slide is borrowed from GE water but the actual numbers on the slides are from “source unknown”

40 %

S I N G A P O R E

Where SingaporeWhere Singapore’’s water comes from?s water comes from?

Hyflux Kristal 600 Hollow Fiber Ultra-Filtration Membranes

•Testing method : Out-to-inside, 1bar

2Fiber Length (Meter)

3 - 4Tensile Strength (MPa)

200-400Initial Pure Water Flux(LMH@1 bar)

60kMWCO (Dalton)

1.15/0.60/0.27OD/ID/Wall Thickness (mm)

Modified PESMaterial

600BKristal MEMBRANE

Kristal 600 Membranes

Morphology of K600B Hollow fiber MembraneWei X, Chung T. S. “Development of a Hybrid System to Improve the Anti-Fouling Performance of the UF Membrane during the Specific Industrial Wastewater Treatment”, AIChE Annual Meeting, Salt Lake City, USA, 4-9 November 2007 Hyflux CEO, Ms. Lum

Developed by Dr. Wei Xi (Hyflux) and Prof. Neal Chung (senior consultant) in 2007Prof. Chung also led and built the Hyflux membrane R & D team in 2004-2008

Nano-filtration (NF) Hollow Fiber Membranes to Remove Toxic Ions in Water

0

20

40

60

80

100

0 2 4 6 8 10 12 14

Solution pH, [-]

Rej

ectio

n of

chr

omat

e, [%

]

20 bar10 bar

[CrVI] = 0.001 M

HCrO4-

H2CrO4

Cr2O72-

CrO42-

• Toxic anions, e.g. phosphate, arsenate, arsenite, borate anions, chromate ions• Heavy metal cations, e.g. copper ions

PBI NF fiber

Wang, Chung, Investigation of polybenzimidazole (PBI) nanofiltration hollow fiber membranes for the removal of chromate, J. Membrane Science, 281, 307 (2006).

Lv, Wang, Chung, Investigation of amphoteric polybenzimidazole (PBI) nanofiltration hollow fiber membrane for both cation and anions removal, Chemical Engineering Science, 62, 6032 (2008).

Rejection of (a) positively charged dye, Safranin O, and (b) negatively charged dye, Orange II sodium salt, solutions.

The left bottle is the feed solution while the right bottle is the permeate.(The feed solution concentration: 50ppm, pH 5.75. Pressure:5 bar)

(b) Orange II sodium salt

C16H11N2O4S -, Na+, 350.32 Da

(a) Safranin O

C20H19N4+, Cl-, 350.84 Da

RT=99.80% RT=98.75%

Thin film composite nano-filtration

hollow fiber membrane

Sun et al, Env. Sci. & Tech, 2011.

World Oil Price Chronology: 1991-2009 http://www.wtrg.com/daily/crudeoilprice.html

• High oil prices have changed the balance of desalination technologies 

• High oil prices have encouraged the seek for low‐energy separation processes   

1991‐2005

0

10

20

30

40

50

60

70

80

Sep 19,1991

Jun 15,1994

Mar 11,1997

Dec 06,1999

Sep 01,2002

May 28,2005

US$per 

barrel

2008‐2012

Now ≈100

Electricity is the largest cost in reverse osmosis (RO)

Average global cost of desalinated water in 2008 = $3.67 per thousand gal

Chemicals3%

Electricity44%

Depreciated capital37%

Maintenance & labor11%

Membranes5%

Source: Cleantech Group

= $3.67/3.785 = US$0.96/m3

Chemical Engineering News (Oct 19, 2009) 1 Gallon = 3.785411784 Liters

Derived from crude oil

How much % if the oil price reaches

$150-200?

Historic and forecasted world desalination capacity

RO

Thermal

What types of new membranes for desalination?

What types of new thermal processes?

High oil prices have encouraged us to think and look for new desalination technologies

1998

2008

80 85 90 95 2000 05 10 15 2020 Year

Thermal

RO70

60

50

40

30

20

10

0

Capacity million m3/day

Thermal

RO

Every thirsty country is looking for low-energy

desalination technologies

Emerging Membrane Technologies for Water Reuse and Desalination

2. Forward Osmosis

(a small MD pilot system at NUS )

1. Membrane distillation 3. Biomimetic Membrane

aquaporin

38

Membrane Distillation (MD)Membrane Distillation (MD)

It involves the transport of watervapor through the hydrophobicmembrane pores via a temperaturedifference across the membrane

Feed/Retentate

Distillate/PermeateT2

T1

TF

TD

Jv

Advantages

‐ 100% (theoretical) rejection of salts, colloids macromolecules, cells, and other non‐volatiles

‐ Small energy footprint‐ Lower operating temperatures and pressures‐ Integration with waste‐heat and natural energye.g. solar and geothermal

Benefits

100% pure water Small footprint

Energy saving Lower operating cost

A small MD pilot system in my lab

Why Membranes Distillation Has Not Been Commercialized?

1. Limitations on membrane materials & structure Highly hydrophobic against

– Pore wetting– Intrusion of seawater

Low heat conductivity– Materials chemistry– % Porosity– Structure of porosity

• Fouling

2. The provision of low-cost heat is needed to lower the operation cost (i.e., using hot spring or solar energy)

Tf

Tp

Vapor flux

Heat flux

Pf

Pp

Temperature and Partial Pressure Profiles

Permeate

Membrane

WaterVapor

Pore wetting

Hot Seawater

Seawater intrusion

Temperature polarization

NUS is the pioneer in developing high performance PVDF membranes for Membrane Distillation Technologies

0

10

20

30

40

50

60

70

80

90

65 70 75 80 85 90 95

Temp (ºC)

Flux

 (kg/m

2hr

)

our works (HF)commercial HFcommercial flat sheet

• Developed 3 generation PVDF hollow fibers with fluxes surpass commercially available membranes.

• Dual-layer polyvinylidene fluoride (PVDF)Hydrophilic-hydrophobic composite hollow fiber membranes

0140 050

Hydrophilic layerHydrophobic layer

Wang et al. Chem. Eng. Sci., 63, (2008) 2587; Bonyadi and Chung, J. Membr. Sci., 331, (2009) 66; Teoh and Chung, Sep. Pur. Tech., 66, (2009) 229; Wang et al., Ind. Eng. Chem. Res. (2009); Bonyadi et al., AIChE J., 55, (2009) 828; Bonyadi et al., US Provisional Patent, No. 61/193,359 (2008).

49.6μ329.6μm

Cross section

10 most-cited articles in the AIChE Journal from 2009http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1547-5905/homepage/MostCited.html

1. Capillary forces between two solid spheres linked by a concave liquid bridge: Regions of existence and forces mapping David Megias-Alguacil, Ludwig J. Gauckler; Volume 55, Issue 5, May 2009, p 1103-1109

2. A heuristic design procedure for water-using networks with multiple contaminants, Zhi-Yong Liu, Yi Yang, Lin-Zhan Wan, Xi Wang, Kai-Hu Hou; Volume 55, Issue 2, February 2009, p 374-382

3. A coupled DEM/CFD analysis of the effect of air on powder flow during die filling, Y. Guo, K. D. Kafui, C.-Y. Wu, C. Thornton, J. P. K. Seville; Volume 55, Issue 1, January 2009, p 49-62

4. Methane steam reforming at microscales: Operation strategies for variable power output at millisecond contact timesGeorgios D. Stefanidis, Dionisios G. Vlachos, Niket S. Kaisare, Matteo Maestri; Volume 55, Issue 1, January 2009, p 180-191

5. A C1 microkinetic model for methane conversion to syngas on Rh/Al2O3, Matteo Maestri, Dionisios G. Vlachos, Alessandra Beretta, Gianpiero Groppi, Enrico Tronconi; Volume 55, Issue 4, April 2009, p 993-1008

6. Modeling of a continuous rotary reactor for carbon nanotube synthesis by catalytic chemical vapor depositionSophie L. Pirard, Jean-Paul Pirard, Christophe Bossuot; Volume 55, Issue 3, March 2009, p 675-686

7. A novel approach to fabricate macrovoid-free and highly permeable PVDF hollow fiber membranes for membrane distillation, Sina Bonyadi, Tai Shung Chung, Raj Rajagopalan; Volume 55, Issue 3, March 2009, p 828-833

8. Increased gas solubility in nanoliquids: Improved performance in interfacial catalytic membrane contactorsMarc Pera-Titus, Sylvain Miachon, Jean-Alain Dalmon; Volume 55, Issue 2, February 2009, p 434-441

9. Three-dimensional simulations of biofilm growth in porous media, D. A. Graf von der Schulenburg, T. R. R. Pintelon, C. Picioreanu, M. C. M. Van Loosdrecht, M. L. Johns; Volume 55, Issue 2, February 2009, p 494-504

10. Characterization of microseparator/classifier with a simple arc microchannel, Nobuo Oozeki, Shinichi Ookawara, Kohei Ogawa, Patrick Löb, Volker Hessel; Volume 55, Issue 1, January 2009, p 24-34

Diluted draw solution

Concentrated draw solution

Fresh water

Feed (seawater)

Concentrated brine

FO membrane

NUS is the First Designing PBI Nanofiltration (NF) Hollow Fiber Membranes for Forward Osmosis (FO) Process

Wang, Chung, Qin, Polybenzimidazole (PBI) nanofiltration hollow fiber membranes applied in forward osmosis process, J. Membrane Science, 300, 6 (2007).

Yang, Wang, Chung, Dual-layer hollow fibers with enhanced flux as novel forward osmosis membranes for water reclamation, Environmental Sci. & Tech. 43, 2800–2805 (2009)

Wang, Yan, Chung, Enhanced forward osmosis from chemically modified polybenzimidazole (PBI) nanofiltration hollow fiber membranes with a thin wall, Chem. Eng. Sci. 64, 1577 (2009)

Draw solution regeneration

Draw solutions:1) Concentrated salts2) NH4HCO33) Magnetic particles4) Many others

1st

generation

CA flat sheet and hollow fiber membranesWang et al. I&EC, (2010)

Zhang et al, JMS (2010), CES (2011)Su et al, JMS (2010), (2011)

Single layer PBI Dual Layer PBI/PES

NUS Forward Osmosis Membranes for Water Reuse and Desalination

(4-5 US patents have been filed)

40

Thin-film interfacial polymerized FO membrane

Wang et, J. Membrane Science (2007), Chem. Eng. Sci. (2009)

Yang et al, Environmental Sci. & Tech. (2009).

Wang & Chung AIChE J (2011)

1st Designing Magnetic Nano-particles as Draw Solutes for Forward Osmosis Process

Diluted draw solution

Concentrated draw solution

Feed (seawater)

Concentrated brine

FO membrane

Draw solution regeneration

N S

Product (water)

Magnetic field

Magnetic nano-particles recycled back to FO

• high osmotic pressure • recovery by magnetic field

water soluble magnetic nano-particles

M. M. Ling, K. Y. Wang, T. S. Chung, Highly water soluble magnetic nanoparticles as novel draw solutes in forward osmosis for water reuse, Industry and Engineering Chemistry Research. 49, 5869–5876 (2010).

(A US patent has been filed)

filtrate collection

filtrate vs. draw solution

magnetic separation

Magnetic separation of water soluble magnetic nano-particles solutions

47

Applications of forward osmosis (FO) membranes

Pharmaceutical industry: osmotic pump for drug delivery

Hydration bag: Consisting of two bags:

1. the internal bag is made of FO membrane and full of draw solution;

2. the external bag is a plastic bag containing feed water.

Drug OutletWater

FO membrane

FO Applications as Power PlantsRenewable energy can be extracted wherever two streams of different

salinity or different chemical potential meet

Source: http://www.statkraft.de/Images/Statkraft%20Osmotic%20Power_tcm4-5362.pdf

The power plant is similar to a RO desalination plant but operating backwards.

The forecasted price for the power plant will be €40-50/MWh, comparable to other renewable energy resources

Clean river water

http://osmoticpower.com/

13 bars: a waterfall of 135 meters in a

hydropower plant

The FO membrane is the heart of the whole

process

Characteristics of FO Membranes• Semi-permeable• High water flux• High solute retention • Low concentration polarization• Low fouling• High stability at different pH levels • High resistance to chlorine

Osmotic power generation from the mixing of seawater and fresh water

River water

Seawater

Membranes for energy (CH4 and H2) and CO2 capture

Hydrogen