sub-department of environmental technology 06-0068 energie uit water prof.dr.ir. cees j.n. buisman...
TRANSCRIPT
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