OVERVIEW AND ROADMAP FOR MEMBRANE PROCESS DEVELOPMENT IN DESALINATION · PDF...

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SMTC

OVERVIEW AND ROADMAP FOR MEMBRANE

PROCESS DEVELOPMENT IN DESALINATION

Tony Fane

Singapore Membrane Technology Centre

DesalTech 2015, San Diego, Aug 28-29,2015

Member of NEWRI Ecosystem

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Outline

• Context

• Status

• Research Developments

• Roadmap and the Future

• Conclusions

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Global Water Stress

Climate change and economic growth

Context

Source CSIRO

Predicted trend is hotter and drier

2030

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Singapore and Water

Water 274ML/d

Desalination 455

NeWater 500*

Wastewater MBR 23

MBR 2x60 to NeWater

(i) GE Zenon end 2014

(ii) 2016

Reclamation (NeWater) > SWRO

* 2060 Targets

Desal = 30%, NeWater > 50%

6th NEWater

UF/MF etc

SWRO

Power

Gen

PRO

RED

PRO

RED

Biogas

RO

MD

Cryst

Nonsaline

Saline

Sea/brackish Used water

QH

Potable &

Industry

WATER

INPUT

WATER

OUTPUT

POWER

[Potable]

Industry

brine

brine

saline

nonsaline

nonsal

[ED]

[MD]

CASP/UF

MBR

Potable &

Industry

UF/NF/FO

solids

Membranes and the Water Domain Fane, Wang, Hu, Status & Future of Membranes for Water, Angew. Chemie Intl, 54 (2015), 3368

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D Furakawa, 2008, NWRI

2006

~ 14,000 MLD

2013/14

> 35,0000 MLD

12% growth

(G.Pearce)

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Drinking Water (60%)

+ Pretreatment

MBRs etc

Low Pressure Membranes

Submerged (Suction)

Trend to Contained?

(Pressurized)

• Water Reclamation . All use LP membrane pretreatment.

• Seawater Desalination plant.

- Trend is to LP membrane pretreatment.

- Magtaa (Hyflux) 500 Mld desal = 1000 Mld Pretreatment

Mainly hollow fibre polymeric

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Low Pressure Membranes

Application Share by Market Value as a Function of Time Period for Membrane Filtration in Water & Wastewater 1985-2015

Greame Pearce : The Pearce Report; Low Pressure Membranes (in Prep) IDA Conf: Session S-18, Tues pm Room E

Pretreatment

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Sea water RO: Plants & Modules – Getting Larger

M.Kurihara (Toray)

Sorek, Israel , 624 MLD (2013) largest SWRO plant.

16 inch modules

Vertically aligned

RO growth is 10 to 15%

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M.Kurihara (Toray)

RO Plant – Getting Larger

Mega Ton Water Project (Japan)

Sorek , 624 MLD

Magtaa, 500 MLD

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Outline

• Context

• Status

• Research Developments

•Roadmap and the Future

• Conclusions

- Novel RO Desalination Membranes - Electrodialysis - Membrane Distillation - Forward Osmosis - Bioreactors

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Pendergast & Hoek, Energy & Env.Sci. (2011), 4, 1946-1971

The Quest for ‘Ultra permeable’ (UPM) RO membranes

Graphene

Revolutionary

Evolutionary

Far Now

Hollow Fibres AqP

R.Wang et al., Recent data-submitted

100%

R.Wang et al., JMS 494 (2015) 68-

Flat Sheet AqP

50%

Y Zhao et al., JMS,

423 ( 2012)

Evolutionary & Now

AqPAsia

FS

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Publications CNT

desalination Web of Sci. , Aug, 2015

Publications Graphene

desalination Web of Sci. , Aug, 2015

Title Topic

Title Topic

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Press Release March 25, 2015

Sumedh.S.et al, ‘Water desalination using nanoporous single-layer graphene’ Nature Nanotechnology, 10, (May 2015) , 459-464. FO Mode data:

A value = 70 g m-2 s-1 atm-1 = 250 LMH per bar (> 20 xcurrent)

Support is SiN microchip, Am = 5 micron.

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UPM potential Carbon NT, Graphene

Aquaporin

Evolution of RO Permeability

Fane,Wang,Hu, Angew Chemie Intl, 54 (2015), 3368

Advances in material science

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?

Can we anticipate a ‘step change’ in RO permeability ? Could we use a ‘step change’ in RO Permeability ?

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Electro dialysis Publications Electrodialysis desalination

Web of Sci. , Aug, 2015

Topic Title

EDR desalination brackish river water (200 MLd)

Desal 253 (2010) 170-174

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Process X ?

Sea water feed WHO standard DW

1.5 kWh/ m3

100mm filter UF ED + CEDI Post treat

Evoqua (Siemens WT)

Singapore’s Desal Challenge (2008)

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Membrane Distillation - Long gestation but interest continues

= 1370

~600 in last 4 yrs Publications MD in title Web of Sci. , June, 2015

• ZLD—MD crystallization

• FO draw regeneration

• Novel bioreactors

• Low GHG option

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PVDF nanofiber

Nanoparticle coating

b

a

1

0 2 4 6 8

0

20

40

Flu

x (K

gm-2

hr-1

)

Time (hr)

0

10

20

30

40

50 PVDF

S-PVDF

I-PVDF

Per

mea

te C

ond

uct

ivit

y (m

S)

Novel MD Membranes (Vapour transport: highly porous , hydrophobic)

Liao et al. JMS 425 & 440 (2013)

0 2 4 6 8

0

20

40

Flu

x (

Kg

m-2

hr-1

)

Time (hr)

0

10

20

30

40

50 PVDF

S-PVDF

I-PVDF

Commerical PVDF

Per

mea

te C

on

du

ctiv

ity

(m

S)

Electrospun with nanoparticle coating is super hydrophobic (Contact angle = 153 deg),with

good flux and no wetting.

EWI Project 0901-02-03

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Forward Osmosis - Still a hot topic

Publications FO in title Web of Sci. , Aug, 2015

Title

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FO Membrane Evolution at SMTC

A increases, B/A decreases S parameter decrease

FO TFC Hollow Fibers

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FEED PRODCT

FO Processes

Draw I (Engineered) + regeneration process - Various options

Draw II (Available) diluted for use / discharge - Seawater, brine, etc

Feed

Feed

Seawater, brine, etc

Water

Concentrated Feed

Diluted Draw

Regen

Membrane Draw Regen

Desalination

FOMBR

Concentration

Pretreatment

Dilution

PRO

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FO to reduce Produced Water volumes using thermal brines

FO

Produced water

50% Vol reduced

Deep well injection

Diluted brine

Thermal desal brine

Temperature Orientation

ConocoPhillips Global Water Sustainability Centre, Qatar & SMTC (Desal. –in press)

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Pressure-retarded Osmosis

Statkraft

15 bar 20 W/m2

Bench mark

has been

5W/m2

SMTC PRO hollow fiber

@ 15 bar has power

density of 20 W/m2

Power generated from SWRO brine ~

0.3 - 0.5 kWh/m3 brine.

Reduce net energy for SWRO plant

EWI Project 1102-IRIS-07-01

Optimum Pressure ~ 25 bar Best membrane/module ?

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Membrane Bioreactors A key component in Reuse/Reclamation

Membrane bioreactor(s) or MBR in title

ANAEROBIC Membrane

bioreactor(s) or MBR in title

Peak interest ? Growing interest ?

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MBR Future Trends

• Anaerobic MBRs are gaining interest

• Potential for net energy production

• Reduces GHG emissions of wastewater treatment

P.McCarty et al. ES&T, 45 (2011)

Anaerobic Fluidized Bed MBR (Inha/Stanford)

Singapore: EWI Project: (Inha/Stanford/NTU)

produced

used

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Outline

• Context

• Status

• Research Developments

• Roadmap and the Future

• Conclusions

SMTC US Roadmap report (2003)

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Angewandte Chemie Int.Ed. 54, 3368-3386

(2015)

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Possible Futures for Membrane Processes in Water*

* Angewandte Chemie Int.Ed. 54, 3368-3386 (2015)

RO/NF

• Potential energy savings: SWRO (15% - (25%)) & BWRO (45 %)

Cohen-Tanugi et al. EES (2014) 7. Assume : Permeability increased 3X

• Potential module savings (higher flux): SWRO (15 to 25%) & BWRO (40 %)

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Limited by mass transfer k

DP = 50 bar DP = 25 bar Assume: perfect rejection, no fouling.

Increase K

J = A (DP – exp (J/k).DP)

Typically: A = 1.0-2.0 l/m2.hr.bar k= 100 l/m2.hr (= 28x10-6m/s)

UPMs require Modules with enhanced Mass Transfer, k

typical k

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Strategies for improved k

Zamani, Chew et al, Desal. 356, (2015) 328-348

• Unsteady-state shear to enhance mass transfer k

Increase of k by 2x to 3x possible.

Easier with hollow fibers!

Partl Fluidization

Other Vibrations Gas Sparging

VSEP

• Novel spacer design.

3 D printed prototypes

Various spacers

Mass transfer coefficient

Pressure drop

Chong et al. EWI Project

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UPM potential

Carbon NT

Graphene

Aquaporin

Practical upper limit

required

Evolution of RO Permeability

• Getting close to upper limit of useful permeability • Constraint is module design and mass transfer

Fane,Wang,Hu, Angew Chemie Intl, 54 (2015), 3368

Advances in material science

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-0.3 kWh/m3

-2.2 kWh/m3

- 2.5

Reducing primary energy - SWRO

Intake RO plant Pretreat UF/MF

Energy Recovery

Post-treat

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-0.3 kWh/m3

-2.2 kWh/m3

- 2.5

Intake RO plant Pretreat UF/MF

Energy Recovery

Post-treat

- 0.01 kWh/m3

-1.6 to -1.7 kWh/m3

BSUF, Biofilt etc UPM RO Close to OP operation PRO power

+ 0.3 kWh/m3

- 1.3 to -1.4

Reducing primary energy - SWRO Potential to almost halve membrane energy demand

Trade off is additional capital & foot print.

Close to osmotic pressure – multistage or CCD Gravity driven biostabilized

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FO (1) RO seawater

low salinity stream (WWRO)

FO – RO Hybrids

FO (2)

[PRO]

RO seawater

low salinity stream

brine dilutebrine

I. FO dilution reduces osmotic pressure of SWRO feed.

II. FO (as PRO) recovers osmotic power from RO brine.

Brine is diluted prior to discharge. • FO 1 dilutes seawater with energy benefit to SWRO.

• PRO 2 recovers energy from brines and dilutes SW brine.

• Potential to halve energy / m3 water product.

• Trade offs

• Product has impaired water origin.

• Requires collocation of SWRO and Water Reuse plant.

Cath et al., JMS 362 (2010)

Sim et al. Membrane, (2013)

D Kim et al. JMS 483 (2015)

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Possible Futures for Membrane Processes in Water*

* Angewandte Chemie Int.Ed. 54, 3368-3386 (2015)

UF/MF

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Comparison of Longitudinal and Transverse Vibrating Hollow Fibre Membranes

Zamani, Law, Fane, JMS 429 (2013) 304

• Transverse vibrations upto 5x the maximum shear rate and upto 1/20th the TMP rise.

• Could this apply for RO – for enhanced k ?

Expt CFD

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Possible Futures for Membrane Processes in Water*

* Angewandte Chemie Int.Ed. 54, 3368-3386 (2015)

Membrane Bioreactors

(An)MBR RO

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UASB FO (SMTC HF)

MD (55 C)

QH

FO MD

• Product < 5 ppm TOC, TN • Biogas at ~ 75% theoretical • Stable fluxes > 10 LMH

Potential for net energy production and reclaimed water

• FO-MD Anaerobic MBR

Reversible fouling tendency of FO membranes an advantage

DS 0.5M NaCl

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Possible Futures for Membrane Processes in Water*

* Angewandte Chemie Int.Ed. 54, 3368-3386 (2015)

MD

FO/PRO

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Some Final Comments on Trends

• Decarbonisation-Desalination and Renewable Energy

• Fouling Control and Sensors, Smart Systems

Flow

0.00.2 0.4 0.6 0.8 1.0

X (mm)

0.2

0.4

0.6

0.8

1.0

Y (

mm

)

Spacer

Feed Retentat

e Permeate

Voltage

electrodes

Membrane

Impedance

Spectrometer

V

+

V

-

I

-

AC current vs

frequency

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SWRO NeWater

Singapore and Water: Reclamation (NeWater) & SWRO

Reclamation > SWRO

Energy and cost to reclaim/reuse is ~ 50% SWRO Desalinate 1 x and Reuse multiple times . Consider the hybrid FO –RO – PRO option.

Anticipate growth in MBR-RO and AnMBR-RO.

A Global Role Model

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Conclusions & Targets for A Road Map

• Aim for 3 (to 5) fold increase in RO permeability.

• At same time more robust and cost effective membranes.

• Increase mass transfer k by 3 to 5x (novel hydrodynamics).

• SWRO: 50% less energy ( novel memb, module, process F/S).

• FO & MD optimized to exploit renewables (osmotic, thermal).

• FO, PRO, MD, RO integrated processes.

• WW reclamation with AnMBR +RO (recover biogas,P etc).

• WWRO > SWRO, integrate and collocate to lower energy.

• Enhanced efficiency & energy usage from improved fouling

control, novel sensors , smart systems etc.

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ACKNOWLEDGEMENTS

EDB Singapore and Environment and Water Industry Programme Office (EWI) under National

Research Foundation (NRF) for supporting the Singapore Membrane Technology Centre.

The SMTC Family

http://smtc.ntu.edu.sg

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THANK YOU

ANY QUESTIONS ?

Cleantech One – Home of SMTC

NTU

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High Retention MBRs

M

W/W

S A

M

W/W

S A

X H2O

H2O

Membrane Distillation Bioreactor (MDBR)

Forward Osmosis Bioreactor (FOMBR)

Driving force : waste heat.

Low GHG options

(ORT = HRT , to improve permeate quality)

Fane et al. PCT/SG2006/000165

Phattaranawik et al., Chem. Eng & Techol., 32 (2009)

Fluxes ~ 10LMH QH

QH

Lay et al. SST 47 (2012)

Zhang et al. JMS 403 (2012)

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High efficiency biotreatment

Low efficiency biotreatment

Water Reclamation

Future trends : MBR + RO

CDOC retention

~ 95%

B.Wu et al. Desalination 311 (2013)

Toray /SMTC

RO fouling depends on MBR performance.

Potential for very low DOC.

Zhang,J. JMS 284 (2006)

MBR RO