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Energie uit water. KIVI/NIRIA 16 oktober 2006. prof.dr.ir. Cees J.N. Buisman. www.wetsus.nl. www.ete.wur.nl. De wereldcapaciteit wordt overschreden. Bio-energie op dit moment belangrijkste renewable. Source IAE 2003. Biomassa is geen schone brandstof.
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Energie uit water KIVI/NIRIA 16 oktober 2006 prof.dr.ir. Cees J.N. Buisman www.wetsus.nl 06-0068 www.ete.wur.nl
Bio-energie op dit moment belangrijkste renewable Source IAE 2003 06-0068
Biomassa is geen schone brandstof Source: Exploring the future Shell International 06-0068
Bio-energie acetaat ipv suiker Primaire productie Suiker energie Primaire productie Acetaat energie 06-0068
Via acetaat is er veel meer energiepotentieel in biomassa Source SenterNovem 2003 06-0068
Hydrogen : 3 $ct/MJ Ethanol : 3 $ct/MJ Electricty : 2 $ct/MJ Methane : 1 $ct/MJ Schone conversie essentieel WET BIOMASS via acetate 06-0068
COD • 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.
B I O A NO D E e- e- e- e- e- e- e- Electrochemically Active Micro-organisms Biological Anode Bacteria COD in Wastewater (e.g. fatty acids) Electrons
Bio-electrochemistry Electrochemically Active Micro-organisms Source: http://www.geobacter.org
Nano Wires Source Nature Reviews 2006
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 SO42- + +8 H+ + 6 e- Etc. These electrons are released at a high energy level! Biological anodes Electron production
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 Microbial Fuel Cell Example Acetic Acid
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-electricity (+1.02 Volt) O2/H2O (0.82 Volt) Microbial Fuel Cell Energy Consumption Bacteria Energie Opbrengst Bacteriën Energy Consumption Bacteria(= Potential loss) Glucose/CO2 (-0.41 Volt) Acetic Acid/CO2 (-0.27 Volt) Biological Anode Potential(~ -0.2 Volt) Bio-Anode Cathode
Microbial Fuel Cell CO2 Exhaust e- e- Effluent(COD-poor) H2O H2O CO2 + H+ Anode Cathode H+ O2 + H+ COD Wastewater (COD-rich) Air = Electrochemically Active MO
Status Power Density: ~100 W/m3 Voltage: 0.2-0.6 Volt Efficiency: 15-30% Performance • Perspectives • Power Density: 1000 W/m3 • Voltage: 0.5-0.7 Volt • Efficiency: ~60% For comparison: conventional anaerobic treatment coupled to agasmotor also produces approximately 1000 W/m3.
Bio electrochemie maakt grote stappen voorwaarts COMMERCIEEL INTERESSANT
The next step SOLAR ENERGY CO2 O2 ASSIMILATES ELECTRICITY MICROBIAL FUEL CELL
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 Biocatalysed Electrolysis Example Acetic Acid
I-0.5 I -0.4 I -0.3 I -0.2 I -0.1 I 0.0 H+/H2 (-0.42 Volt) I 0.1 I 0.2 I 0.3 I 0.4 I 0.5 Hydrogen production requires aninput of electricity (-0.22 Volt) I 0.6 I 0.7 I 0.8 I 0.9 I 1.0 Biocatalysed Electrolysis Energy Consumption Bacteria(= Potential loss) Energie Opbrengst Bacteriën Glucose/CO2 (-0.41 Volt) Acetic Acid/CO2 (-0.27 Volt) Biological Anode Potential(~ -0.2 Volt) Bio-Anode Cathode
Biocatalysed Electrolysis CO2 H2 PowerSupply e- e- Effluent(COD-poor) H2 CO2 + H+ H+ Anode Cathode COD H+ Wastewater (COD-rich) = Electrochemically Active MO
Power Supply Electrochemical Cell Configuration
2 kWh 1.6 m3 H2 Bio-electrochemical System 1 kg COD
160 MW (1.3 % NL consumption) SewageNL 1.1 billion m3 H2 (19 % car km NL) H2 H2 675 MW (5.4% NL consumption) Manure NL 4.6 billion m3 H2 (79 % car km NL) Bio-electrochemical Processes Electricity and hydrogen from sustainable sources
www.wetsus.nl www.ete.wur.nl 06-0068