1. Cellulosic Ethanol and E85 Vehicles
HC399
Cellulosic Ethanol and E85 Vehicles

2. Introduction Ethanol produced by fermenting plant sugars
Worldwide, ethanol is the most commonly used biofuel for transportation
Cellulosic ethanol has many advantages over corn-based ethanol
Applications:
E85 Flexible Fuel Vehicles

3. Ethanol Sources Corn Sugar Cane Cellulosic Ethanol
Currently, primary ethanol source in US (Midwest)
10% ethanol/90% gasoline blend (burns cleaner and increases octane rating)
Sugar Cane
20% of transportation fuel market is from ethanol
7/10 new cars sold in Brazil are flex fuel
$.81/gallon
Cellulosic Ethanol

4. Limitations of Corn-based ethanol
High-energy input
Environmental Impact:
Fertilizer and Pesticide Use
Soil Erosion
Farm machinery and transportation
requirement
Limited supply
DOE: Max ethanol from corn: 12 billion gallons/year
Competes with food supply
Alexander Farrell of UC Berkeley:
Corn-based ethanol instead of gasoline reduces greenhouse gas emissions only about 18% (88% for cellulosic ethanol).

5. Cellulosic Ethanol
Agricultural, industrial, forest, yard and house hold waste: wood, corn stalks, non-edible parts of food crops, yard waste
Energy Crops: Switchgrass, Poplar Trees, Miscanthus
No commercial cellulosic-ethanol plants today
Energy Independence and Security Act of 2007: 36 billion gallons of renewable transportation fuels in the U.S. by 2022.
msnbcmedia3.msn.com/j/msnbc/Components/Photos
biofuelsdigest.com/.../2008/08/miscanthus.jpg

6. Biomass Components
Cellulose is the most abundant organic compound on Earth
Glucose molecules linked together
Cell wall component
Approximately 44% of plant
Hemicellulose
Composed of xylose and other pentoses
Approximately 30% of plant
Lignin
Inhibits conversion of cellulose to ethanol
Necessary for structural support and pest resistance
26% of biomass

7. Why Cellulosic Ethanol?
US could convert 1.3 billion dry tons of biomass a year into 60 billion gallons of ethanol, enough to replace 30% of transportation fuel
Lower energy input and low cost biomass: produced from plant waste or specialized crops
Reduce greenhouse gas emission by 88% compared to gasoline
Cellulose sources take in carbon dioxide
Demand for ethanol could increase further if methyl tertiary butyl ether (MTBE) is eliminated from gasoline

8. Hurdles of Cellulosic Ethanol
Producing cellulosic ethanol at a competitive price
Compared to corn starch and sugar feedstocks, cellulosic materials is harder to break down into fermentable sugars
Requires two additional steps: pretreatment and cellulose hydrolysis
Infrastructure
Industrial scale-up and speed
No current commercial production
Contains approximately 30% less energy/gallon than gasoline

9. Overview of Cellulosic Ethanol Production
Pretreatment
Hydrolysis
Fermentation
Distillation

11. Pretreatment
Need to extract cellulose from lignin and other plant compounds
Acid and Steam
Break hemicellulose component of biomass into simple sugars
Dilemmas:
Difficult to separate cellulose from other plant material such as lignin
Acid and Steam require energy to produce
Acid reacts with sugar reducing yield by 10% and creates byproducts that inhibit fermentation

12. Cellulose Hydrolysis Breaks cellulose into glucose Common Methods
Acid hydrolysis
Enzymatic hydrolysis: cellulase
Dilemmas:
Hydrolysis can create byproducts that inhibit enzymes
Acid generally can’t be re-used

13. Fermentation Microorganisms: Dilemma:
Baker’s yeast (Saccharomyces cerevisiae)
Z. mobilis
Escherichia coli
Dilemma:
Ferment both hexose and pentose sugars into ethanol

14. Research to Improve Cellulosic Ethanol Production
Biotechnology will play
a principal role in advancing cellulosic ethanol production
Goals:
Improve cellulosic feedstock
Increase efficiency of biomass to ethanol conversion
Improve enzymes and microbes ability to create ethanol through fermentation
Much focus on optimizing fermentation
Speed at which bacteria convert sugar into ethanol is much slower than that of yeast. Yeast: few hours to convert bath of glucose to ethanol vs. one to two days for bacteria. Researchers trying to increase bacteria’s expression of the enzymes involved in fermenting

15. Tree Biotechnology
Genetic Engineering of Poplar trees to contain lower levels of lignin
Maximum of 50% reduction of lignin
Controversy of Genetic Engineering
Similar projects in switchgrass and other potential energy crops

16. Genetic Engineering of Microbes
Baker’s Yeast:
Can only covert hexoses to ethanol
Genetically engineered to convert both hexoses and pentoses
Convert sugar into ethanol at a much faster rate than bacteria.
E. coli: insert genes so fermentation product is ethanol instead of lactic acid and acetic acid
Bacteria: E.coli and Z. mobilis:
GE to convert 90-95% of biomass sugars into ethanol
Downside: low tolerance of ethanol
wineserver.ucdavis.edu

17. Thermochemical Through heating and chemical treatment,
Cellulose > CO, CO2, and hydrogen > Ethanol
Through heating and
chemical treatment,
biomass made in to syngas
Syngas can then be converted
into ethanol
Gasification
Microbe

18. Ethanol Applications E85: Flexible Fuel Vehicles
Lignin from biomass can be used to create steam necessary for ethanol production
Biomass could fuel powerplants

19. E85 Vehicles 85% ethanol/ 15% gasoline
Lower % ethanol in winter so vehicle can start
Over 6 million FFVs on road in US
General Motors and Ford say that half their car production will be flexible fuel by 2012
Roughly 1000 E85 stations
Concentrated in Midwest
E85 Stations near Corvallis (11 within 200 miles):
About 28 mi. State of Oregon DAS Motor Pool, Salem Airport Rd. SE Salem , OR Government owned vehicles only.
About 46 mi. SeQuential Biofuels McVay Hwy. Eugene , OR 97405
About 50 mi. Leather's Shell Truck Stop Ehlen Rd NE Aurora , OR 97002
cw50detroit.com/projectgreen

20. Comparison to Gasoline
Cost of E85 fuel is less than gasoline; cost per mile is similar
Comparable power and acceleration
Environmental
Greenhouse gas emission reduction
Greater reduction for cellulosic ethanol than corn-based ethanol
Decrease in benzene (carcinogen) and carbon monoxide
Increase in acetaldehyde (toxic pollutant) and formaldehyde

21. Conclusion
Further advances in research and development of cellulosic ethanol could make it a viable alternative fuel
Low cost biomass, but need to reduce production cost
E85 vehicles: E85 burns cleaner than gasoline and reduces greenhouse gas emissions
Lithium Ion Plug-in hybrids that
run off E85

22. Bibliography: http://www.afdc.energy.gov/afdc/ethanol/e85.html