Cellulosic Ethanol and E85 Vehicles

HC399

http://www.wired.com/science/planetearth/magazine/15-10/ff_plant

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

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 Ethanolhttp://www.hotstocked.com/articles-img/small/corn_ethanol.jpg

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

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.jpgbiofuelsdigest.com/.../2008/08/miscanthus.jpg

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

http://en.wikipedia.org/wiki/Cellulose

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.infowww.all-creatures.org/hope/img/earth-light.jpg

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 gasolinewww.livenowcoaching.org

Overview of Cellulosic Ethanol Production Pretreatment Hydrolysis Fermentation Distillation

http://www.pacificethanol.net/

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

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

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

Fermentation

Microorganisms: Baker’s yeast (Saccharomyces

cerevisiae) Z. mobilis Escherichia coli

Dilemma: Ferment both hexose and pentose

sugars into ethanol

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

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 cropshttp://k41.pbase.com/

v3/64/556764/1/49163116.gladiolifarmingbetweenpoplartrees8886.jpg

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

Thermochemical

Cellulose -------> CO, CO2, and hydrogen -------> Ethanol

Through heating and chemical treatment, biomass made in to syngas

Syngas can then be converted into ethanol

Microbe

Gasification

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

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

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 1100 Airport Rd. SE Salem , OR 97301 Government owned vehicles only.

About 46 mi. SeQuential Biofuels 86714 McVay Hwy. Eugene , OR 97405

About 50 mi. Leather's Shell Truck Stop 12334 Ehlen Rd NE Aurora , OR 97002

cw50detroit.com/projectgreen

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

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

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