Phoenix biotechnology: New materials for tomorrow s

1
Todays Wastes, Tomorrows Energy
Phoenix biotechnology New materials for
tomorrows energy.. From the wastes of todays
society
New ? bio-products
for tomorrow
Bacteria recover materials into new
products Waste minimization Resource efficiency

? Waste materials of today
Unit of Functional Bionano-Materials
2
Conversion of H2 into electricity
H2
Pt on carbon anode and cathode catalysts
2 H2 ? 4 H 4 e-
Anode
Pt catalyst
H
Proton exchange membrane
Pt catalyst
Cathode
O2 4 e- 4 H ? 2 H2O
e- flow
O2
Proton Exchange Membrane-Fuel cell
Required 1.Pt nano-catalyst 2. Clean
hydrogen
Aim Bio-based fuel cell using biohydrogen and
bio-recovered Pt
3
Resources for H2 production
Worldwide biomass residues 2 billion tonnes
burned annually world-wide 1.5 billion tonnes oil
equivalent (1999) Annual UK waste production 17
million tonnes from the food industry 3 million
tonnes from households
4
H2 production by E. coli and its relatives
FHL
Note L.S,E,A divert carbon away from H2
production
5
Effect of pH on E. coli fermentation using glucose
NB 2mol/mol is maximum from dark fermentation
6
Potential feedstocks
NB from confectionery waste conversion was as
for pure glucose see video
7
Ohmic heating increased sugar
8
Chemical effects of ohmic heating
Model fruit waste -HPLC
9.5 mM formate
Propionate
Formate
X
X
Lactate
Acetate
Butyrate
X
9
Dark fermentation H2 from wastes

• Glucose ? H2 organic acids
• E. coli bacteria
• Strain HD701, H2 over-producer
• Mixed acid fermentation
• H2 produced by Hydrogenase enzyme
• 2 mol H2/mol glucose (max)
• Uses wastes

10
Photofermentation H2 from organic acids in light

• Organic acids ? H2 CO2
• Light-driven
• Rhodobacter sphaeroides
• Photobioreactor (PBR)
• High yield, broad substrate range
• e.g. Lactate ? 6 H2
• H2 produced by Nitrogenase enzyme
• Very sensitive to NH4
• Can use wastes with high C/N

11
The dual system
An artificial symbiosis could approach 12 mol
H2/mol (i) Dark Fermentation (E. coli) 1
glucose ? 2 H2 1 Acetate 1 Ethanol
2 CO2 (ii) Photofermentation (R. sphaeroides) 1
Ethanol 1 Acetate ? 10 H2 4 CO2
No single organism can do both steps
12
Dual system
H2
Dark Fermentation
Photo- Fermentation
Organic acids
Glucose
Ammonium ion inhibits H2 photoproduction How to
transfer organic acids without NH4 ? -
Electrodialysis!
13
H2 production (dark fermentation) by fed E. coli
Organic acid buildup inhibits further H2
production
14
Continuous dark fermentation with electrodialysis
15
Continuous Photofermentation
16
Continuous photofermentationfed by
electrodialysis
17
Energy balance for Dual System

• Energy input into electrodialysis 99.5 kJ/day
• Useful products of E. coli
• H2 96 mmol/day (80 efficient dark
  fermentation)
• Mixed organic acids
• H2 potential of extracted organic acids
• 400 mmol H2/day (75 efficient
  photofermentation)
• Total H2 potential
• 590 mmol H2/day
• 168 kJ/day
• Net energy gain 69 kJ/day

Waste CO2 and biomass only process is
carbon-neutral
18
Towards zero-emission
Waste bacteria make catalysts for fuel cells
H2 ? 2H 2e- ? Hydrogenase enzyme (Reverse
direction)
Pd2 Pd0
Bacterial cell
Bacteria can recover precious metals from car
catalysts and electronic scrap
19
Palladised bacteria
Black nanoparticles of palladium metal bound
to bacterial cells
20
PEM-FC with Bio-Pd(0) anode
21
Process summary
Raw wastes
2 wastes ? 2 products
Sugar feed
Ohmic heating
Fermentation
ED
Organic acids
Bacterial cells
H2
Metal wastes
Photofermentation
Sorption reduction
Catalyst
Energy
PEM-FC
22
Thanks
Sponsors EPSRC, BBSRC, EU, Royal Society,
DEFRA Partners C-Tech Innovation Ltd EKB
Ltd Team David Penfold Iryna Mikheenko
Vic Baxter-Plant Ping Yong Mark
Redwood KevinDeplanche Marion
Paterson-Beedle Neil Creamer Movie See
Exhibition Outreach Faraday Partnership
Mini-Waste now Resource Efficiency KTN