Algal Biofuels
with thanks to:
Chris Reddy
Director, Coastal Ocean Institute
Woods Hole Oceanographic
Institution
and in collaboration with:
Scott Lindell (MBL, WHOI)
Emily Peacock
History
Rudolph Diesel (1858-1913); died likely of suicide.
• He developed the idea of an engine using high
compression to ignite the fuel, eliminating the spark
plug.
• Patent awarded in 1892.
• He was interested in using coal dust or vegetable oil
as fuel with a special interest in helping farmers.
History (continued)
• A diesel engine runs on straight peanut
oil in 1900 at Paris Exposition (wins prize)
• Lots of failures using straight vegetable
oils (SVOs).
• It was recognized that it was best to
modify fuels and not engines. Led to
biodiesel (as we know it)
• Interest fluctuates with oil prices in US
Background
•
One of the most promising fuel alternatives is
biodiesel, which is derived from animal and vegetable
fats.
•
Many tout its ability to enhance engine lubrication,
decrease harmful emissions, and minimize the
dependence on foreign oil imports.
•
It is formulated in a variety of mixtures from B2
(2% biodiesel mixed with 98% diesel derived from
fossil fuels) to B100 (100% biodiesel).
• Almost any diesel engine can be run on B2 though
B20.
Distributors of biodiesel in the US
(www.biodiesel.org)
Fats from vegetable oil
Generally liquids at room temperature
18:1
fatty acids
glycerin
18
18:2
Some use this in diesel engines; called straight vegetable oil (SVO)
Fats from animals
Solids at room temperature
18
18
18
What is biodiesel?
They are the fatty acid methyl esters
(FAMEs) that result from the chemical
breakdown of glycerides.
H3C
O
H3C
O
C16 FAME
Biodiesel Production: 3 Step
Trans-Esterification Reaction
Comparison of Properties
☺
Gas chromatography
detector
inlet
60-m long column
Typical gas chromatogram
FID Signal
– components vary in some molecular property that
can be used by a GC stationary phase to separate
them from one another
C10
C12
C14
Time (min)
C16
C18
C20
(n-alkanes)
Hill et al (2006) PNAS
• “Devoting all US soybean production
would have an offset of 6% on diesel
demand……
• “However, because of the fossil energy
required to produce biodiesel, this
change would provide a net energy gain
to just 2.9% of US diesel
consumption…..”
Algae-based bidiesel
– Grow algae and press or extract the
oil from them.
– Algal oil can be transformed with
simple chemical reactions to
biodiesel.
– Many consider it the “biofuel of the
future”
Algal Biodiesel
•
•
•
•
No “food for fuel” issues.
Harvest almost daily.
By products: Glycerine (food and other
industries); Protein (fish farms); etc
Lower emissions when burnt.
One study published in 2007 entitled,
“Biodiesel from Microalgae” in
Biotechnology Advances, indicated
that algal-based biodiesel is the only
biological source capable of replacing
fossil-fuel diesel.
US Energy Department study says
that if algal biofuels replaced
petroleum in the US market, an area
15,000 square miles would suffice (like
Maryland!)
Got algae?
Possible Biofuels “farm”
Photo
Bioreactors
Raceway Pond Product
Algal Concentrate
chemical reaction
algal oil
(algal oil is too viscous to be used
as a fuel alone and must be converted to
biodiesel)
biodiesel
Got algae?
Be careful with the hype
Take data from the “bench” and
extrapolate to millions or even billions
of gallons of water/algae. Problematic?
WHOI and MBL’s initial research
• Involved in a proposal for a one-acre
sized marine biodiesel production site in
Cape Cod.
• Motivated to identify the best algae for
this region.
• Began a survey of local species this past
summer.
Solix plant, CO
What about the cost?
ex. Solix
right now  $33/gallon
paired w/ waste heat & CO2  $5.50/gallon
selling by-products  $3.50/gallon
(but) that’s still $150/barrel!!
goal is to get down to $1.50 gallon
(or $60-80/barrel)
Algal biofuels benefits
• home-grown (less imported oil)
• biological efficiency: algae create
oils that can be harvested every 5-7
days
• energy density (they are 10-60% oil)
• no food-for-fuel problems (unlike
ethanol)
• could use waste CO2 and heat from coal
and gas power plants
Algal biofuels problems
•
•
•
•
•
Will take years to optimize technology.
Cost still high
Still dealing with hypothetical scaling.
Biodiesel is likely short-lived.
Green diesel and other green fuels are
the future on the commercial scale
(same chemical structure as traditional
fossil fuels).