Biofuels
1st gen Ethanol
• Yeast makes EtOH from plant sugar
• Corn, sugar cane, sugar beet, sorghum
• Only use part of plant
• Use crops for fuel instead of food
• Net loss of C
Biofuels
1st gen Ethanol
• Yeast makes EtOH from plant sugar
• Corn, sugar cane, sugar beet, sorghum
• Only use part of plant
• Use crops for fuel instead of food
2nd gen (cellulosic) Ethanol
• Use cell walls as source of sugar for yeast
Biofuels
2nd gen (cellulosic) Ethanol
• Use cell walls as source of sugar for yeast
• Can use entire plant
• Can use non-crops grown on marginal land
• Switchgrass (Panicum virgatum)
• C4 perennial: grows from Mexico to 55˚ N
Biofuels
Switchgrass (Panicum virgatum)
• C4 perennial: grows from Mexico to 55˚ N
• C4 = high water efficiency, also deep roots =
high nutrient efficiency so grows on poor soil
Biofuels
Switchgrass (Panicum virgatum)
• Can yield 5.4 x more energy than needed to
grow, harvest & convert it to ethanol cf 1.3 x
max for corn
• Also used for soil conservation and
phytoremediation
Biofuels
Miscanthus giganteus
• Sterile hybrid of M. sinensis & M. sacchariflorus (both
from Asia)
• C4 perennial that reproduces solely through rhizomes
• Non-invasive cf both parents, even though grows > 4m
tall cf 1-2 m max for both parents
Biofuels
Miscanthus giganteus
• Non-invasive cf both parents, even though grows > 4m
tall cf 1-2 m max for both parents
• High N efficiency + C4 = grows well on barren land
• Can yield 20 tons biomass/acre cf 7.6 for corn & 6 for
switchgrass
Biofuels
Miscanthus giganteus
• Can yield 20 tons biomass/acre cf 7.6 for corn & 6 for
switchgrass
• could supply 12% of the EU's energy by 2050
Trees
• poplar
Biofuels
Miscanthus giganteus
• Can yield 20 tons biomass/acre cf 7.6 for corn & 6 for
switchgrass
• could supply 12% of the EU's energy by 2050
Trees
• Poplar
• eucalyptus
Biofuels
Trees
• Poplar
• Eucalyptus
Can be harvested in 4-5 years
Biofuels
Trees
• Poplar
• Eucalyptus
Can be harvested in 4-5 years
Low maintenance
Biofuels
Trees
• Poplar
• Eucalyptus
Can be harvested in 4-5 years
Low maintenance
Yield <4 tons
biomass/acre cf 20
for M. giganteus
Biofuels
Trees
• Poplar
• Eucalyptus
Can be harvested in 4-5 years
Low maintenance
Yield <4 tons
biomass/acre cf 20
for M. giganteus
Sawdust, other
waste cell walls
Biofuels
2nd gen (cellulosic) Ethanol
• Use cell walls as source of sugar for yeast
• Can use entire plant
• Can use non-crops grown on marginal land
• Problem: lignin & other wall chems
Biofuels
2nd gen (cellulosic) Ethanol
• Problem: lignin & other wall chems
Biofuels
2nd gen (cellulosic) Ethanol
• Problem: lignin & other wall chems
• Chemical hydrolysis
Biofuels
Problem: lignin & other wall chems
• Chemical hydrolysis
• Digest cell walls with enzymes
Biofuels
Problem: lignin & other wall chems
• Chemical hydrolysis
• Digest cell walls with enzymes
• Need a cocktail
Biofuels
Problem: lignin & other wall chems
• Chemical hydrolysis
• Digest cell walls with enzymes
• Need a a cocktail
Fermenting other sugars
Biofuels
Fermenting other sugars
• Use other microbes
• Mutate yeast
Biofuels
Fermenting other sugars
• Use other microbes
• Mutate yeast
Mutate plants to make simpler cell walls
Biofuels
Fermenting other sugars
• Use other microbes
• Mutate yeast
Mutate plants to make simpler cell walls
• 10% of Arabidopsis genes are estimated to be involved
in plant cell wall metabolism
Biofuels
Fermenting other sugars
• Use other microbes
• Mutate yeast
Mutate plants to make simpler cell walls
• 10% of Arabidopsis genes are estimated to be involved
in plant cell wall metabolism
• Many mutants reduce lignin synthesis
Biofuels
Mutate plants to make simpler cell walls
• 10% of Arabidopsis genes are estimated to be involved
in plant cell wall metabolism
• Many mutants reduce lignin synthesis
• Easier to digest cell walls
Biofuels
Mutate plants to make simpler cell walls
• 10% of Arabidopsis genes are estimated to be involved
in plant cell wall metabolism
• Many mutants reduce lignin synthesis
• Easier to digest cell walls
• Easier for pathogens to attack
Biofuels
Mutate plants to make simpler cell walls
• 10% of Arabidopsis genes are estimated to be involved
in plant cell wall metabolism
• Many mutants reduce lignin synthesis
• Easier to digest cell walls
• Easier for pathogens to attack
• More prone to xylem collapse
Biofuels
Biodiesel = fatty acid methyl esters
• Trans-esterify oils to make them volatile
• Renewable Fuels Standard (RFS2): US must use > 1
billion gallons/year in 2012 through 2022
• > 50% reduction in CO2 cf petrodiesel
• Oils can be from seeds, algae, used cooking oil, animals
Biofuels
Problem: are shifting from growing food to growing fuel!
• Raises price of soybeans, corn, etc
• Cut down forests to grow oil crops in tropics
• Is this environmentally sound?
• Depends on real costs of growing, processing and
delivering products
Biofuels
Problem: are shifting from growing food to growing fuel!
• Raises price of soybeans, corn, etc
• Cut down forests to grow oil crops in tropics
• Is this environmentally sound?
• Depends on real costs of growing, processing and
delivering products
• NO! for corn-based ethanol!
• Probably yes for cellulosic ethanol
• Maybe for soy-based biodiesel
• Maybe for other biodiesel
• What are the real costs?
• What else could be grown?
Biofuels
Maybe for other biodiesel
• What are the real costs?
• What else could be grown?
• Best to grow in places unsuitable for other crops
• Pickleweed in salt marshes
Biofuels
Maybe for other biodiesel
• What are the real costs?
• What else could be grown?
• Best to grow in places unsuitable for other crops
• Pickleweed in salt marshes
• Algae (up to 60% oil) can generate 10x more oil/acre
• Grow in sewage, etc?
• Mutate to divert more photosynthate to lipids,
ethanol, biogasoline, H2 or electricity!
Biofuels
What else could be grown? Plants that release H2?
Biofuels
What else could be grown? Plants that release H2?
Plants that make electricity?
Biofuels
What else could be grown? Plants that release H2?
Plants that make electricity?
Plants that make plastic, antibodies, etc?
Biofuels
What else could be grown? Plants that release H2?
What else could be done?
http://www.coskata.com/process/
Biofuels
What else could be grown? Plants that release H2?
What else could be done?
• Burn crops to make electricity?
Biofuels
What else could be grown? Plants that release H2?
What else could be done?
• Burn plants to make electricity?
• 2x better energy recovery than ethanol or diesel
Biofuels
What else could be grown? Plants that release H2?
What else could be done?
• Burn plants to make electricity?
• 2x better energy recovery than ethanol or diesel
• EthosGen (Jim Abrams) wants to build an ethanol
production plant in Newport Township
Biofuels
What else could be grown? Plants that release H2?
What else could be done?
• Burn plants to make electricity?
• 2x better energy recovery than ethanol or diesel
• EthosGen (Jim Abrams) wants to build an ethanol
production plant in Newport Township
• Army likes their idea, except want them to make
electricity instead!
Biofuels
What else could be grown? Plants that release H2?
What else could be done?
• Burn plants to make electricity?
• 2x better energy recovery than ethanol or diesel
• EthosGen (Jim Abrams) wants to build an ethanol
production plant in Newport Township
• Army likes their idea, except want them to make
electricity instead!
Conclusion: Renewable fuels are feasible
Biofuels
What else could be grown? Plants that release H2?
What else could be done?
• Burn plants to make electricity?
• 2x better energy recovery than ethanol or diesel
• EthosGen (Jim Abrams) wants to build an ethanol
production plant in Newport Township
• Army likes their idea, except want them to make
electricity instead!
Conclusion: Renewable fuels are feasible
• Bioethanol/biodiesel are stopgaps
Biofuels
What else could be grown? Plants that release H2?
What else could be done?
• Burn plants to make electricity?
• 2x better energy recovery than ethanol or diesel
• EthosGen (Jim Abrams) wants to build an ethanol
production plant in Newport Township
• Army likes their idea, except want them to make
electricity instead!
Conclusion: Renewable fuels are feasible
• Bioethanol/biodiesel are stopgaps
• Bioelectricity is best long-term plan
Biofuels
Conclusion: Renewable fuels are feasible
• Bioethanol/biodiesel are stopgaps
• Bioelectricity is best
long-term plan
• Direct current (eg solar panels?)
Biofuels
Conclusion: Renewable fuels are feasible
• Bioethanol/biodiesel are stopgaps
• Bioelectricity is best
long-term plan
• Direct current (eg solar panels?)
• Hydrogen via water-splitting?
Biofuels
Conclusion: Renewable fuels are feasible
• Bioethanol/biodiesel are stopgaps
• Bioelectricity is best
long-term plan
• Direct current (eg solar panels?)
• Hydrogen via water-splitting?
• Something else?
Biofuels
Conclusion: Renewable fuels are feasible
• Bioethanol/biodiesel are stopgaps
• Bioelectricity is best long-term plan
• Direct current (eg solar panels?)
• Hydrogen via water-splitting?
• Something else?
• Photosynthetic vehicles
& houses?
Biofuels
Conclusion: Renewable fuels are feasible
• Bioethanol/biodiesel are stopgaps
• Bioelectricity is best long-term plan
• Direct current (eg solar panels?)
• Hydrogen via water-splitting?
• Something else?
• Photosynthetic vehicles
& houses?
We can learn a lot from plants!