Green Design Initiative

1
Ethanol
2
Ethanol

• Conversion of sugars to ETOH
• The manufacture of alcoholic beverages originated
  over 5000 years ago
• Water was generally impure and thus fermented
  juices provided a level of protection from
  spoilage by their high alcohol content

3
Ethanol as a fuel

• Long History
• Anhydrous ethanol used as an internal combustion
  engine fuel in the late 19th century
• In 1906 Congress removed the tax on ethanol to
  encourage farmers to use it as a fuel
• With appropriate pre-treatment various forms of
  biomass can be used
• Brazil National Alcohol Program
• Effort to replace gasoline with ethanol
• Since 1975 over 50 billion liters of alcohol made
• 40 of Brazils 14 million cars used ethanol (95
  ETOH/5 H20)
• 60 used 78 gasoline 12 ETOH
• US is the second largest alcohol producer
• 1980 Energy Security Act
• Gasohol - 10 ETOH - about 7 of total nationwide
  gas sales
• lead free, produces less NOx and CO
• 2001 1.8billion gallons of Ethanol produced
  mainly from corn
• Cost-competitiveness based solely on government
  subsidies

4
Ethanol fuel properties in relation to fuel
performance
From Lynd 1996Bailey 1996
5
Reasons to use Ethanol

• Energy security
• Ethanol offers substantial environmental
  benefits.
• Ethanol makes gasoline burn cleaner.
• Ethanol reduces greenhouse gas emissions.
• Ethanol is made from abundant renewable
  resources.
• Ethanol is good for farmers and rural economy.

6
Dry Milling Simplified Process
7
(No Transcript)
8
Poplars
9
Poplar Plantation
10
Poplar Cutting
11
Switchgrass Stand
12
Switchgrass
13
Switchgrass Bale
14
Simplified Bioethanol Process
Detoxification Via Ion Exchange
Dilute Acid Pretreatment
Liquid Solid Separation
Size Reduction
Biomass
Enzyme Production
SSCF Fermentation
Fuel Grade Ethanol
Separation
Solids Processing Cogen
15
Current Ethanol Costs
16
Effect of Biomass Cost on Ethanol Production Cost
17
Natural Vegetation and Ag/Urban Waste
From Lynd (1996)
18
Waste Ag Cellulosics

• Corn stover is available in the highest amounts -
  100 to 200 million tons per year.
• Bagasse could contribute another 700,000 tons.
• If all of the corn stocks and bagasse were
  collected, about 6.5 billion gallons of ethanol
  could be produced annually.
• Only 30 to 60 of the total stover and bagasse
  could be collected, reducing the potential
  ethanol to 2 to 4 billion gallons annually.

19
Sugarcane, Corn, Switchgrass Comparison
20
Variability of the literature calculations
21
Biomass Yields from Literature
Hohenstein Wright
Rainey Mann
Wright et al.
Cook Beyea
Downing et al.
22
Gross Calculation

• 195 billion gallons of ethanol needed
• Using Switchgrass
• 195 to 600 million acres of land

23
Land Use in the Contiguous 48 States
Proportion of Total Area ()
Acreage (Million Acres)
Use
Grassland Pasture Range Forest Cropland Special
Use Other Use
589 559 460 194 92
31 30 24 10 5
24
Environmental Impact

• Food vs. energy
• Land use competition
• Soil quality
• Water quality
• Chemical inputs
• Biodiversity
• monoculture
• suitability for wildlife habitat
• landscape effects
• stability

25
Greenhouse gas emissions reduction

• Burning fossil fuels converts old biomass into
  new CO2 - this then contributes to the
  greenhouse effect
• Burning new biomass contributes no net CO2 if
  we replant the harvested biomass or burn biomass
  specifically grown for energy generation (energy
  crops)

26
Greenhouse gas emissions (Corn)
27
Greenhouse gas emissions (Biomass)
28
(No Transcript)
29
(No Transcript)
30
Pipeline Infrastructure
31
Fuel Consumption
32
Ethanol Production
33
Fuel Mix
Baseline Consumption
E85
E10
E0