Cellulosic Ethanol and E85 Vehicles

1. HC399 Cellulosic Ethanol and E85 Vehicles http://www.wired.com/science/planetearth/magazine/15-10/ff_plant

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

3. Ethanol Sources • Corn • 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 http://www.hotstocked.com/articles-img/small/corn_ethanol.jpg

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). http://www.umassvegetable.org/images/soils_crops_pest_mgt/crop/corn5.jpg

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 www.vtnews.vt.edu/images/poplar250.jpg 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 xyloseand other pentoses • Approximately 30% of plant • Lignin • Inhibits conversion of cellulose to ethanol • Necessary for structural support and pest resistance • 26% of biomass http://en.wikipedia.org/wiki/Cellulose

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 www.eco-cars-online.info www.all-creatures.org/hope/img/earth-light.jpg

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 www.livenowcoaching.org

9. Overview of Cellulosic Ethanol Production • Pretreatment • Hydrolysis • Fermentation • Distillation http://www.pacificethanol.net/

10. http://www.verenium.com/images/pic_research_cellulosic_dia.gifhttp://www.verenium.com/images/pic_research_cellulosic_dia.gif

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 www.globalwarmingart.com

13. Fermentation • Microorganisms: • Baker’s yeast (Saccharomycescerevisiae) • 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 http://en.wikipedia.org/wiki/Cellulosic_ethanol

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 http://k41.pbase.com/v3/64/556764/1/49163116.gladiolifarmingbetweenpoplartrees8886.jpg

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 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 http://simonwilliambaird.files.wordpress.com/2008/04/syngas_brand.jpg

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

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): 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 http://gas2.org

22. Bibliography: • http://www.afdc.energy.gov/afdc/ethanol/e85.html • http://www.energy.ca.gov/research/renewable/biomass/ethanol/index.html • Http://www.nrel.gov/biomass/pdfs/40742.pdf • http://www.energy.gov/news/4827.htm • http://www.ethanolrfa.org/resource/cellulosic/ • http://www.sciencemag.org/cgi/content/full/315/5818/1488 • http://www.epa.gov/smartway/growandgo/documents/factsheet-e85.htm • http://www.e85refueling.com/ • http://yaleglobal.yale.edu/display.article?id=6817 • http://www.eia.doe.gov/oiaf/analysispaper/biomass.html • http://www.ers.usda.gov/Publications/FDS/2007/05May/FDS07D01/fds07D01.pdf