1. Sugar cane to ethanol (Lecture 3)

2. Agenda Dedicated energy crops Sugar cane to ethanol Energy balance
History
Sugar cane-the ideal feedstock?
How do they do it?
Discussion
Why is the sugar cane to ethanol process so successful in Brazil?
What else could be done to improve the process?
What can we learn from Brazil?

3. Dedicated energy crop
Dedicated energy crop: plants grown specifically for applications other that food or feed.
Planted and harvest periodically
Annual basis (sugar cane)
3-10 year cycle (hybrid poplar)
Dedicated energy crops contain significant quantities of one or more of 4 energy rich components
Oils
Sugars
Starches
Lignocellulose
Herbaceous energy crops (HEC) (annuals and perennials)
Sugar cane, energy cane, napiergrass, sorghum
Short-rotation wood crops (SRWC)
Willow, oak, poplar, maple, eucalyptus

4. Sugar cane, sugar cane bagasse
Processing
Ethanol

5. Sucrose
α-D-glucopyranosyl- (1↔2)-β-D-fructofuranoside
Sucrose accounts for little more than 30% of the chemical energy stored in the mature plant; 35% is in the leaves, which are left in the fields during harvest, and 35% are in the fibrous material (bagasse) left over from pressing
Sucrase or acid are needed to break down sucrose into glucose and fructose

6. Sugar cane bioethanol (1)
Brazil produces 3,96 billion gallons/year of ethanol from sugar cane
Production cost $0.87/gallon, the lowest in the world
Fossil fuel energy used to make the fuel (input) compared with energy in the fuel (output) 1:8
Green house emission during production and use 56% less compared with gasoline

7. Oil price (1)

8. Oil price (2)

9. Gasoline price

10. History (1) 1920 utilization of ethanol as a transportation fuel
Early 1970,
1973-oil embargo (oil 3x more expensive)
1974-sugar prices
Late 1975 Brazilian National Alcohol program (20% blend)
Mid 1980
All the cars sold in Brazil ran on alcohol
Early 1990
Oil
Sugar

11. History (2) 2003 Total Flex Car (gasoline and ethanol) Gol-Volkswagen
Currently 85% of cars are flex

12. Sugar cane growers
Brazil, India, China, Thailand, Australia, South Africa, Mexico and Guatemala

13. Sugar cane in Brazil

14. Fields of sugar cane in Brazil

15. Sugar cane Harvest after 1 year to 18 months
Harvest starts in April
7 harvests before replanting
Harvested by hands or machinery
20% of sugar cane are sugars
gallons of ethanol/acre (more than 2x compared with corn)

16. Problems Environmental problems Social problems Amazon-deforestation
Burning the cane pre-harvesting
Use of pesticides and herbicides
Utilization of fields next to the rives (against Brazilian law)
Social problems
Pay
Hot, dirty and backbreaking
Snakes
Cuts
Air quality

17. Fields of sugar cane

18. Sugar cane

19. Burning

20. Harvesting (1)

21. Harvesting (2)

22. Transportation

23. Washing

24. Crushing

25. Sugar cane bagasse

26. Fermentation and distillation

27. Could we have this type of gas station in US?

28. Discussion Why sugar cane to ethanol is such as successful process?
What else could be done to improve the process?
What could we learn from Brazil?