Capacitive Deionization

of Sea and Brackish Waters

Clean Drinking Water and Storing Energy!

OECD Paris 2009

Doing Things PORELY!But Not POORLY !

In the Land of the Lilliputians…

Fe2O3

MnO2

CdS

Al2O3MgO

NiO

SiO2

ZrO2

TiO2

Particle

Flavors

α-FeOOH Adsorption 1974-

Natures Nanoparticulate “Tongue Depressors”

Suspensions

Platelets

!

α -FeOOH “Goethite”

Arsenate

Phosphat

e

Protons!!

Adsorbs…

Without PO4-3

With PO4-3

From Suspensions to Thin-Films

Ceramic

Membranes

1983-

Now – Smaller Particles

Nanofiltration

γ– AlOOH

“Boehmite”

Platelets

!

Photo & Photoelectrocatalysis

1991-TiO2

3nm

Films vs Suspensions

No Separation Needed

Better Light Penetration

Photoelectrodes

Transparent Semiconducting Thin-Films

Photoelectrochemistry

Grätzel Cells

Porous Electrodes !

Lubomir

Spanhel

Hirofumi Kikkawa

Energy Storage

Batteries

Capacitors

Ultracapacitors

1994-MnO2

8nmC = ε

A

d

dA

Ion Distance to Surface = Angstroms

Fa

Power Density

En

erg

y D

en

sit

y

batteries

capacitors

ultracaps

Faster Response

Longer Cycle Life

USA

Alkaline

Battery

Load-Leveling

ENERGY

WATER

POWER PLANTS NEED WATER!

Rhone River Plant- France

WATER PLANTS NEED ENERGY!

Adelaide Australia

DELIVER WATER

&

STORE ENERGY?

CAPACITIVE

DEIONIZATION!

History of CDI

Caudle et al 1960’s

Oren et al 1970-1980’s

Farmer et al 1990’s

FIFTY YEARS BUT NO COMMERCIAL SUCCESS ?

Our

System

S-OH2+ = S-OH0 + H+

S-OH0 = S-O- + H+

Proton is a Potential Determining Ion

THE PROTON HAS RETURNED!

Choosing Capacitor Materials

SiO2

TiO2

2 4 6 8 10

Al2O3

pH

Ze

taPotential

+

-

MgAl2O4

The pH range of Normal Waters.

CaCl2 Removal

How Effective is Coating?

Zero Removal in

20 minutes

for Uncoated Carbon

CaCl2 Removal with

Coatings

90% Removal in

20 minutes

Other Ion Removal

Note: Calcium is Difficult if Not Impossible to Remove

with Carbon Aerogels Capacitive Systems!

CDI vs RO

Reduced Energy (>30%)

Reduced Fouling (>60%)

Less Brine (>40%)

Low Maintenance Cost (>50%)

Higher Throughput (>70%)

Lower Capital Costs (>40%)

Third World Water

Solar Powered CDI For A Family of Four

Where Do We Go From Here?

Senior 5-Year Proposal

To Be Continued . . .

Marc A. AndersonUniv. of Wisconsin – Madison

Imdea Energia - Madridwww.marc-tech.com