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Biofuels

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Title: Does it take more energy to make ethanol than is contained in the ethanol? Author: Ellen Thomas Last modified by: Wesleyan University Created Date – PowerPoint PPT presentation

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Title: Biofuels


1
Biofuels
2
Why are biofuels attractive?
  • Energy security locally produced, wider
    availability, grow your own oil
  • Climate change mitigation one of the few
    low-carbon options for the transport sector
  • Lower emissions of various harmful pollutants
    (e.g., sulfur)
  • Liquid fuels conducive to existing
    infrastructure, storage, distribution
  • Bioethanol cars, light trucks, motorcycles
  • Biodiesel commercial vehicles, buses, pumps,
    isolated electricity generation

3
Biofuel production
  • Ethanol
  • Sugarcane (Australia, Brazil, China, Colombia,
    Ethiopia, India, Thailand), sugar beets (EU)
  • Maize / Corn (US, China)
  • Wheat (Canada, EU)
  • Cassava (Thailand)
  • Biomass wastes (cellulose) forest products
    (Canada), wood wastes, agricultural
    residuesmaize stover, sugarcane trash
  • Energy cropsswitch grass, hybrid poplar, willow
  • Biodiesel
  • Rapeseed (EU)
  • Soybeans (US)
  • Palm oil (Malaysia)
  • Coconut oil (Philippines)
  • Plants growing on marginal landJatropha,
    Karanja (India)

4
USDA, July 2006
5
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6
Greenhouse Gases
  • We burn fossil fuel (coal, oil fossilized
    plants and microscopic algae) MUCH faster than it
    is formed - Middle East oil 110 million years
    old US coal 320 million years old.
  • CO2 H2O -gt CH2O O2 (photosynthesis) reverse
    reaction-burning, decay respiration
  • Biofuels every year burn as we grow - crops
    pick up CO2 in photosynthesis, we put it back by
    burning -gt no net effect on concentration of
    greenhouse gases

7
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8
Things to consider
  • Alternative fuel what are its TOTAL costs?
  • Example hydrogen-powered cars what does it cost
    (energy, environmental) to make the hydrogen?
  • Biofuels energy costs of growing include
    watering, fertilizer production, transport of
    fertilizer and crop, costs of seed grain, cost of
    government subsidies, environmental pollution
    clean-up, income from byproducts
  • Other factors job creation, competition with
    food production, environmental pollution through
    fertilizer use, and so on

9
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10
Does it take more energy to make ethanol than is
contained in the ethanol?
  • SIMPLIFIED
  • 1980 yes
  • 1990 probably not
  • 2005 no
  • the ethanol industry, in terms of energy use per
    gallon of ethanol produced, has become much more
    efficient over the years, as has the farmer, in
    terms of energy use per bushel of corn grown

11
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14
Efficiency
  1. Yield of ethanol per acre
  2. Net energy yield (ratio of energy in / energy
    out)
  3. Expenses as compared to that of gasoline derived
    from oil, combined with miles/gallon (cars need
    30 more ethanol than normal gas per mile
    driven)

15
  • 1 acre sugar beets 720 gallons
  • 1 acre sugarcane 695 -720 gallons of ethanol
  • 1 acre of corn 350-420 gallons of ethanol
  • 1 acre of sorghum 172 gallons of ethanol

16
USDA, July 2006
17
Energy ratios
  • Corn to ethanol 1.3 (mean current techniques)
    to 1.7 (best present techniques)
  • Cellulose ethanol use enzymes to digest
    cellulose) - not yet fully functional.
  • Estimated 3-6
  • Sugar cane - sugar beets 6-8 (including energy
    generated through byproduct burning)
  • Difference in fermentation processes of starch
    (in corn) and sucrose (in sugar crops) higher
    efficiency of sugar

18
COSTSWorld raw sugar vs. gasoline price
Rotterdam unleaded regular gasoline 4Q 2005 US
dollars
SourceWorldbank
19
COSTSBrazil worlds lowest-cost sugar producer
  • Favorable climate, plentiful land, good soil, and
    abundant rainfall in Center-South (cane
    cultivation water intensive)
  • Use of bagasse for plant energy use and surplus
    electricity sales
  • Between 1975-2000, sugarcane yield per hectare
    increased by 33, sugar content of cane 8,
    ethanol yield from sugar 14, fermentation
    productivity 150
  • Modern sugar production and processing and high
    level of managerial skills
  • More than 500 commercial varieties of cane (each
    plant processes around 15 varieties)
  • Hybrid sugar mill/distillery complexes
  • Planting, harvesting, and plant operations
    computerized

20
Source USDA 2002
Brazilian ethanol is cheapest
21
Sugarcane-ethanol Advantages
  • Higher ethanol yield per acre
  • Lower energy costs
  • Higher net energy balance
  • Bagasse is used for production of steam power
  • Could received 2.5 credits for every gallon
  • Lower Volatile Organic C emissions

22
Sugarcane-ethanol Disadvantages (production
within US)
  • Higher feedstock costs
  • Higher cane transportation costs
  • Higher processing costs
  • Higher labor use and labor costs
  • Higher expenses for repairs, maintenance, and
    parts
  • Higher expenses for general and administration

23
Source Brazilian Government
24
Source Brazilian Government
25
Source Brazilian Government
26
Prospects for biofuels
  • Near term
  • Ethanol from sugarcane best overall chance of
    commercial viability
  • Biofuel trade liberalization beneficial to all
    consumers
  • Biodiesel remains expensive relative to world oil
    prices
  • Medium term
  • Fall in production costs
  • New feedstocks
  • Growing trade
  • Long term
  • Commercialization of cellulosic ethanol
    widespread availability, abundance, and
    significant lifecycle GreenHouse Gas emission
    reduction potential
  • Higher oil prices favoring biofuel economics

SourceWorldbank
27
In Summary
  • Significant use of biofuel-ethanol will reduce
    emissions of greenhouse gases significantly
  • Corn ethanol production IS energy efficient
  • Sugar-crop ethanol production (within US) is more
    efficient than corn ethanol production (BUT
    climate, water availability, costs)
  • Import of ethanol from Brazil would lower costs
    for consumers in the US if sugar tariffs are
    abandoned/ lowered (globalization) - no benefits
    for US farmers
  • Further research is needed to investigate
    production of cellulose - ethanol (bacterial
    enzyme action) and other compounds (butanol)
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