Sub-department of Environmental Technology 06-0068 Energie uit water prof.dr.ir. Cees J.N. Buisman KIVI/NIRIA 16 oktober 2006.

06-0068Sub-department of Environmental Technology

Energie uit water

www.wetsus.nl

www.ete.wur.nl

prof.dr.ir. Cees J.N. Buisman

KIVI/NIRIA

16 oktober 2006

06-0068Sub-department of Environmental Technology

De wereldcapaciteit wordt overschreden

06-0068Sub-department of Environmental Technology

Bio-energie op dit moment belangrijkste renewable

Source IAE 2003

06-0068Sub-department of Environmental Technology

Biomassa is geen schone brandstof

Source: Exploring the future Shell International

06-0068Sub-department of Environmental Technology

Primaire productie

Suiker energie

Primaire productie

Acetaat energie

Bio-energie acetaat ipv suiker

06-0068Sub-department of Environmental Technology

Via acetaat is er veel meer energiepotentieel in biomassa

Source SenterNovem 2003

0

20

40

60

80

100

120

140

160

PO

TE

NT

IAL

[P

J/yr

]

Sugar Acetate

06-0068Sub-department of Environmental Technology

Schone conversie essentieel

WET BIOMASS

Hydrogen : 3 $ct/MJ

Ethanol : 3 $ct/MJ

Electricty : 2 $ct/MJ

Methane : 1 $ct/MJ

via acetate

06-0068Sub-department of Environmental Technology

Elektriciteitsproductie uit Rioolwater

Biobrandstofcel + 2 kWh/kg COD

Aërobe zuivering - 0,5 kWh/kg COD

Anaërobe zuivering + 0,9 kWh/kg COD

Sub-department of Environmental Technology 06-0068

• COD = Chemical Oxygen Demand

• Used to generalize all dissolved (bio)-oxidizable material in wastewaters.

• Value expresses the amount of oxygen needed to completely oxidize the (bio)-oxidizable material.

• Represents the amount of potential energy contained in the wastewater.

COD

Sub-department of Environmental Technology 06-0068

Electrochemically Active Micro-organisms

COD in Wastewater

(e.g. fatty acids)

e-

e- e-

e-

e-

e-

e-

BIO

ANODE

Biological Anode

Electrons

Sub-department of Environmental Technology 06-0068

Electrochemically Active Micro-organisms

Bio-electrochemistry

Source: http://www.geobacter.org

Sub-department of Environmental Technology 06-0068

Nano Wires

Source Nature Reviews 2006

Sub-department of Environmental Technology 06-0068

• Glucose: C6H12O6 + 6 H2O 6 CO2 + 24 H+ + 24 e-

• Acetic Acid: CH3COOH + 2 H2O 2 CO2 + 8 H+ + 8 e-

• Sulfur: S0 + 4 H2O SO4

2- + + 8 H+ + 6 e-

• Etc.

• These electrons are released at a high energy level!

Electron production

Biological anodes

Sub-department of Environmental Technology 06-0068

• Biological Anode: CH3COOH + 2 H2O 2 CO2 + 8 H+ + 8 e-

• Cathode: 2 O2 + 8 H+ + 8 e- 4 H2O

• Overall: CH3COOH + 2 O2 2 CO2 + 2 H2O +

electricity In theory: ~1 Volt

Example Acetic Acid

Microbial Fuel Cell

Sub-department of Environmental Technology 06-0068

Microbial Fuel Cell

Glucose/CO2 (-0.41 Volt)Acetic Acid/CO2 (-0.27 Volt)

Energie Opbrengst Bacteriën

O2/H2O

(0.82 Volt)

Bio-electricity(+1.02 Volt)

Energy Consumption Bacteria

I -0.5

I -0.4

I -0.3

I -0.2

I -0.1

I 0.0

I 0.1

I 0.2

I 0.3

I 0.4

I 0.5

I 0.6

I 0.7

I 0.8

I 0.9

I 1.0 Bio-Anode Cathode

Biological Anode Potential(~ -0.2 Volt)

Energy Consumption Bacteria(= Potential loss)

Sub-department of Environmental Technology 06-0068

Microbial Fuel Cell

Anode

Cathode

e- e-

CO

DC

O2 +

H+ O

2 + H

+H

2 O

= Electrochemically Active MO

H+

Air

H2O

CO2 Exhaust

Wastewater(COD-rich)

Effluent(COD-poor)

Sub-department of Environmental Technology 06-0068

Configurations

Sub-department of Environmental Technology 06-0068

Performance

• Perspectives Power Density:

1000 W/m3

Voltage:0.5-0.7 Volt

Efficiency:~60%

• Status Power Density:

~100 W/m3

Voltage:0.2-0.6 Volt

Efficiency:15-30%

For comparison: conventional anaerobic treatment coupled to agasmotor also produces approximately 1000 W/m3.

Sub-department of Environmental Technology 06-0068

Bio electrochemie maakt grote stappen voorwaarts

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

8-jul-02 8-jul-03 7-jul-04 7-jul-05 7-jul-06 7-jul-07 6-jul-08 6-jul-09

Datum

Ver

mo

gen

sdic

hth

eid

(m

W/m

2 an

od

e o

pp

ervl

ak)

COMMERCIEEL INTERESSANT

Sub-department of Environmental Technology 06-0068

The next step

ELECTRICITYMICROBIAL FUEL CELL

CO2

ASSIMILATES

SOLAR ENERGY

O2

Sub-department of Environmental Technology 06-0068

• Biological Anode: CH3COOH + 2 H2O 2 CO2 + 8 H+ + 8 e-

• Cathode: 8 H+ + 8 e- 4 H2

• Overall: CH3COOH + 2 H2O 2 CO2 + 4 H2

In theory: 0.14-0.22 Volt required In practice: <0.5 Volt required

Example Acetic Acid

Biocatalysed Electrolysis

Sub-department of Environmental Technology 06-0068

Biocatalysed Electrolysis

Glucose/CO2 (-0.41 Volt)

Acetic Acid/CO2 (-0.27 Volt)

Energie Opbrengst Bacteriën

H+/H2

(-0.42 Volt)

Hydrogen production requires aninput of electricity (-0.22 Volt)

Energy Consumption Bacteria(= Potential loss)I -0.5

I -0.4

I -0.3

I -0.2

I -0.1

I 0.0

I 0.1

I 0.2

I 0.3

I 0.4

I 0.5

I 0.6

I 0.7

I 0.8

I 0.9

I 1.0

Biological Anode Potential(~ -0.2 Volt)

Bio-Anode Cathode

Sub-department of Environmental Technology 06-0068

Biocatalysed Electrolysis

Anode

Cathode

e- e-

CO

DC

O2 +

H+

H+

H2

= Electrochemically Active MO

H+

CO2 H2PowerSupply

Wastewater(COD-rich)

Effluent(COD-poor)

Sub-department of Environmental Technology 06-0068

Configuration

Power Supply

Electrochemical

Cell

Sub-department of Environmental Technology 06-0068

1 kg COD

2 kWh

1.6 m3 H2

Bio-electrochemical System

Sub-department of Environmental Technology 06-0068

Manure NL

675 MW (5.4% NL consumption)

4.6 billion m3 H2 (79 % car km NL)

SewageNL

160 MW (1.3 % NL consumption)

1.1 billion m3 H2 (19 % car km NL)

Bio-electrochemical Processes

Electricity and hydrogen from sustainable sources

06-0068Sub-department of Environmental Technology

www.wetsus.nl

www.ete.wur.nl