Fuels of the Future
The Bioalcohol Paradigm
ethanol
bridge fuels
lignocellulosic
liquid fuel feedstocks
yeast
phytomass
advanced biofuels
energy synthetic biology
branched-chain fermentation
alcohols
CDC PHIL /James Gathany
original slides by: Drew Sowersby (May 2011)
_technical contributor for Advanced Biofuels USA
www.AdvancedBiofuelsUSA.org
Message to the reader
The following slide document has been created to inform a broad audience
about the importance and likely dominance of bioalcohols in the
transportation industry as the global transition from non-renewable fossil
fuels to renewable advanced biofuels gains momentum. The information
contained in these slides stands in support of the Advanced Biofuels USA
mission.
“The Mission of Advanced Biofuels USA is to promote public understanding, acceptance, and
use of advanced biofuels by promoting research, development and improvement of advanced
biofuels technologies, production, marketing and delivery; and by promoting the sustainable
development, cultivation and processing of advanced biofuels crops, and agricultural and
forestry residues and wastes.”
These slides are for public consumption and can be duplicated, replicated,
modified, adapted, distributed, transmitted, and/or shared as seen fit by the
reader. Please credit sources accordingly. If you wish to modify this
document, just add your name under mine on the first slide.
Note: Some slides contain additional information in notes section below
Concerted efforts from scientists, farmers, politicians, and grassroots
organizations like Advanced Biofuels USA to understand and advocate for
sustainability are ongoing. Most of us are seeking the promise of global
security, the development of a sustainable workforce, and an endless
supply of clean renewable energy.
Converting biomass to biofuels for transportation fuel applications is
currently one of the most active areas of investigative research in science
and engineering. The following sections will offer an in-depth technical
perspective of liquid fuels and demonstrate the overriding potential of
bioalcohols to bridge transportation energy needs of modern society with
the future of the human race.
1. Energy: The Root of All Civilization
2. Why Bioalcohols?
Blending Bridges to Sustainability
3. Leaping Barriers: Squeezing the Sun
Section 1
Energy:
The root of all civilization
In the beginning there was…..biofuels?
1 EJ = 1018 J
The post civil war exploitation of coal
helped spawn the Industrial Age, while the
subsequent incorporation of crude-oil and
natural gas fossil resources helped spawn
what has become a global economy. Is this
pattern sustainable? Most believe the
answer to this question is NO! Why?
In this section the ongoing energy crisis can be
visualized in a series of graphs depicting the startling
connection between:
1.
2.
3.
4.
Energy Consumption
GDP per capita (prosperity)
Population growth
Debt (deficit spending)
chart by : http://perotcharts.com/2008/05/growth-of-us-population-1790-2050/
http://8020vision.com/2010/06/21/the-real-population-problem/
U.S. primary energy use by fuel (1980-2035)
120
Projections
1.0 × 1015 Btu
100
Biofuels
80
40%
Liquids
60
Natural gas
40
Nuclear
20
Coal
0
1980
1995
2008
2020
U.S. Energy Information Administration (Washington, DC, June 2009)
Projections: AEO2010 National Energy Modeling System
2035
Breakdown of the U.S.
liquid fuel market
•
35 quadrillion Btu’s (37 EJ) of liquid energy annually
•~
95% of all liquids since 1958 have come from petroleum 1
• 63% of refined petroleum was delivered to market as motor
gasoline for transportation2
• less than 3% biofuels
1. Energy Information Administration, Annual Energy Review 2008, Petroleum Consumption:
Transportation Sector, 1949-2008. 2009, U.S. Department of Energy, Washington, D.C
2. O’Donnell, M. Master’s Thesis, University of Texas at Austin, 2009
Global transportation energy consumption
vs. GDP in 2006
graph from: http://environmentalresearchweb.org/blog/2009/07/high-debt-and-energy-return-on.html
Energy and Economic
Interconnectedness
http://tclocal.org/images/failure-feedback.jpg
Summary
It appears there exists a positive correlation
between energy consumption, population
growth rate, GDP, and the abstractions of
expanding debt and monetary instability. So
now what?
We must now consider alternatives to the
current trends of fossil fuel dependence and
moves toward sustainability. The next
section will discuss the biofuels option with
an in-depth analysis of the bioalcohol
paradigm.
Section 2
Why Bioalcohols?
Blending Bridges to Sustainability
What are biofuels?
Biofuels are any biologically derived solid,
liquid, or gas that stores energy used in
combustion applications.
In contrast to fossil fuels, biofuels….
1. Are sustainable (1-100 yrs vs. 106-108 yrs)
2. Can be carbon neutral or negative
3. Have a more diversified, distributed means of
production
4. Can be created as reagent grade molecules (pure)
BIOFUEL
TYPES
Alternative Transportation Fuels
Commercially available
Methanol
Natural Gas
Propane
Biodiesel
Electricity
Ethanol
Hydrogen
Under investigation and development
Biobutanol
Fischer-Tropsch (FT) diesel
Gas to Liquids (GTL)
Biogas Biomass to Liquids (BTL)
Coal to Liquids (CTL)
Hydrogenation-Derived Renewable Diesel (HDRD)
P-Series (gasoline substitute)
Source: The Energy Policy Act (EPAct) of 1992
biofuels
biomass
adapted by: Drew Sowersby
Million Barrels per Day
chart by: http://tclocal.org/images/eia-liquidfuels.jpg
Source: U.S. Department of Energy’s Energy Information Agency (EIA).
Million barrels day
Global biofuel supplies expected
to increase dramatically
less than 2% of total
liquid consumption
more than 90% of all cars
use sugarcane ethanol
BP p.l.c., Statistical Review, BP Energy Outlook 2030, London, January 2011
The evolution of biofuels is defined in terms of
the carbon feedstock used for production
1st generation fuels
• corn-starch
CO2
impact factor
• sugar from cane and beets
• soy for diesel
2nd generation – multi-component cellulose
(medium to high lignin content)
• switchgrass
• miscanthus
• agriculture and food processing residues
• poplar trees
net 0
3rd generation – high quality cellulose
(low to no lignin)
• microalgae
• macroalgae (seaweed)
•cyanobacteria
4th generation - sun fuels
• carbon dioxide + light + biocatalyst…
Bioalcohols currently dominate
commercially available biofuels
sugar
feedstocks
fermentation
biomass
The Bioalcohol
Paradigm
product
recovery
market 1
market 2
market 3
chemical
Storage
Biomass
to
Biofuels
http://www.vsjf.org/project-details/13/biomass-to-biofuels-resources
biomass
process generalization
bioalcohols
Most cellulosic material, like woods and
grasses, contains lignin
Lignocelluloses represent the most
abundant source of bioenergy
Glucose
Treatment with cellulases and/or acids
releases glucose monomers for fermentation
Rubin, E. Nature, 2008, 454, 841-845.
But lignocellulosic feedstocks
are not easily converted to
sugar substrate and can
introduce over 100 inhibitors
into fermentation batches1
phenols
organic acids
CLASSES of
inhibitors
aldehydes
ketones
1. Liu, Z. L.; Slininger, P. J.; Gorsich, Appl Biochem. Biotechnol., 2005, 124, 451-460.
So far, Saccharomyces cerevisiae have
demonstrated the ability to perform with a
lignocellulosic feedstock.
Advantages
• Are the most common microorganisms
used for production of biofuels
(primarily alcohols)
• Are eukaryotic
• Have simple nutrient requirements
• Are prime targets for bioengineering
• Convert glucose to ethanol with
unusual efficiency (FERMENTATION)
The yeast cell factory has been used by
humans for over 8000 years to create a host of
useful renewable products
Standard fermentation in yeast
Glucose
Glycolysis
(regulated and irreversible steps)
CO2 + H2O
respiration
amino acid
synthesis
CO2 + CH3CH2OH
Fermentation
Higher alcohol
synthesis
Ehrlich
Pathway
O2
Pyruvate
Yeast cells naturally create C4 and C5
alcohols using fermentation enzymes
BCAAs
(leucine, valine, isoleucine)
BAT1,
BAT2
transamination
(step 1)
branched-chain alcohol synthesis
2-Keto acids
PDC1, PDC2,
PDC3, PDC5,
PDC6, ARO10,
THI3 (KID1)
Ehrlich Pathway
decarboxylation
(step 2)
Ketoaldehydes
+
CO2
NADH-dependent
reduction
(step 3)
ADH1, ADH2,
ADH3, ADH4,
ADH5, ADH6,
SFA1, etc.
superior alcohol fuel surrogates
Branched-chain alcohols
2MB
2MP
3MB
Fermentation as a complex
adaptive system
Temperature
Excess sugar
pH
Inhibitors
Viscosity
Biocatalyst
Fluid Motion
Gases (CO2 and O2)
Nitrogen Source
Ionic Strength
Water
Hypothetical Interaction Map
Isobutanol (2MP) is a viable
platform molecule
GEVO, Inc.
isobutanol
conventional motor
gasoline
Highlights
• High yield isobutanol yeast fermentation (105 g/L per batch)
• Conversion to hydrocarbons
• Carbon emissions reduction of 85%
• Competes with oil at $65 a barrel
source: GEVO, Inc.
C4-C5 Alcohol Platform
ButylFuel, LLC
Highlights
After logging 10,000 miles
butanol….
• increased auto mileage by 9%
• reduced oxides of nitrogen by 37%
• reduced carbon monoxide to 0.01%
• reduced hydrocarbons by 95%
first American company to
commercialize butanol
Case Study:
“Production of Butyric Acid and Butanol from Biomass”
Ramey D and Yang S-T, Phase II STTR Final Report for D.O.E. (2004)
C4-C5 alcohols have advantages
compared to ethanol
 higher energy density





lower vapor pressure
lower air/fuel ratio
less corrosive
less hygroscopic
higher gasoline blend ratios
o “drop-in” fuel
 compatible with gasoline engines,
existing storage facilities, and
distribution infrastructure
1. Harvey, B. J.; Meylemans, H. A. J Chem Technol Biotechnol., 2011, 86, 2–9.
2. Dürre, P. Biotechnol. J., 2007, 2, 1525-1534.
Selected bioalcohol and gasoline properties
Boiling
point
(°C )
Solubility
in water at
20°C
(g/L)
Vapor
pressure
at 20°C
(mm Hg)
Fuel
Cn
Energy
density
(MJ/L)
Gasoline
4-12
33
38-204
negligable
275-475
Ethanol
2
21
78
miscible
59
2-methyl-1propanol*
4
26
108
95
9
3-methyl-1butanol
5
28
130
30
2
2-methyl-1butanol
5
28
128
36
(at 30°C )
3
--information obtained from MSDSs, Sigma-Aldrich website, and NIST
chemistry WebBook.
* a.k.a. isobutanol ~ 1-butanol
MJ/L
Liquid Fuel Energy Densities
butanol/pentanol
sweet spot?
MJ/kg
Source:Scott dial http://en.wikipedia.org/wiki/File:Energy_density.svg
Adapted by Drew Sowersby
Right now fuel blends are showing up at
pumps across the U.S.
BRIDGE FUELS
E10
o Up to 10% ethanol to replace MTBE
E15 - E85
o contains 15% to 85% ethanol
o requires post 2001 or Flexfuel
engine technology
B20
o contains 20% biodiesel / 80% diesel
o made commercially from soybeans
How long until we see C4 and C5
advanced alcohols at the pump?
Section 3
Leaping Barriers:
Squeezing the Sun
The Obstacle Course
It would be irresponsible to assume that human energy
needs will be fulfilled in a timely fashion. The transition to
sustainable energy will likely be a long arduous process.
Moore’s Curse and the Great Energy Delusion (The American
Magazine, November 19, 2008)
“There is one thing all energy transitions have in common: they are
prolonged affairs that take decades to accomplish,
and the greater the scale of prevailing uses and
conversions the longer the substitutions will take. The second part of this
statement seems to be a truism but it is ignored as often as the first
part: otherwise we would not have all those unrealized predicted
milestones for new energy sources.”
- Vaclav Smil-Distinguished Professor at the University of Manitoba.
Technical Barriers
GOAL
Sheer size required
for economic
growth
Geographic
distribution
START
Supply
continuity
Low crop
energy density
Kerr, R. Science, 2010, 329, 780-781
The Bright Side
The sun delivers about 1000 W/m2
of power to Earth’s surface.
• 1000 Wh = 1 kWh = 3.6 mega Joules (MJ)
• peak sun hour = 1 kWh
• peak sun hours per day based on geo location
http://pvcdrom.pveducation.org/SUNLIGHT/AVG.HTM
U.S. example?
≈ 4.00 peak sun hours avg./day1
1 peak sun hour = 3.6 MJ
14.4 MJ/(m2)day × 365 days × 9.83 × 1012 m2
US land area
≈ 5.20 × 1016 MJ/year
1 MJ = 994.78 Btu
≈ 4.90 × 1019 Btu/year
this is roughly 500X the current
amount of US energy usage
1. Solar Radiation Data Manual for Flat-Plate and Concentrating Collectors
National Renewable Energy Laboratory (NREL), 2006
Earth?
≈ 2.00-3.00 peak sun hours/day
7.2 MJ/(m2)day × 365 days × 5.14 × 1014 m2
≈ 1.35 × 1018 MJ/year
≈ 1.28 × 1021 Btu/year
“Using detailed land analysis, Illinois researchers have
found that biofuel crops cultivated on available land could
produce up to half of the world's current fuel consumption
– without affecting food crops or pastureland. Adding LIHD
(low input high density) crops grown on marginal grassland
to the marginal cropland estimate from earlier scenarios
nearly doubled the estimated land area to 1,107 million
hectares globally, even after subtracting possible pasture
land – an area that would produce 26 to 56 percent of the
world's current liquid fuel consumption.” -http://cee.illinois.edu/cai_biofuel_land
Published in the journal Environmental Science and Technology, the study led by civil and
environmental engineering professor Ximing Cai identified land around the globe available to
produce grass crops for biofuels, with minimal impact on agriculture or the environment.
What will the next transition be?
CO2 and the SUN
NON-FOOD crops and
waste/residues
Paradigm Shift
standard fermentation
to
advanced fermentation
FOOD crops
1st generation
biofuels
2nd generation
biofuels
Taking Us from the Present
to the Future
Many companies are engaged in making these
transitions happen.
See a list of more than 400 companies in the
Resources section on the Advanced Biofuels USA
web site:
http://advancedbiofuelsusa.info/resources/compan
ies-involved-with-advanced-biofuels
Find out more at www.AdvancedBiofuelsUSA.org