Biodiesel production from micro-algae
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Transcript of Biodiesel production from micro-algae
Dr. Amer Alzobaay
Baghdad University
What is Microalgae ?
• Algae
– Eukaryotic
– Most live in water
– Freshwater and Marine
– Photosynthetic
• Capture light energy
• Convert inorganic to organic matter
– Use lipids and oils to help float in water
– Range from small, single-celled species to complex multicellular species, such as the giant kelps
Types
• Red Algae
– Macro
• Green Algae
– Chlorophyll a
and b
– Freshwater
• Brown Algae
– Kelp
– Marine
• Diatoms
– Single celled
– Silica cell wall
• Blue Green Algae
– Fix N2 from air
– Freshwater
• Dinoflagellates
– Toxic; suck out O2
– Organic matter
Background
• Location– Most habitats
• How many– Over 36,000 species
• How does it feed?– Photosynthesis
– All have chlorophyll
• Uses– food, fertilizer, footstock,
pharmaceutical, pollution control,
water treatment, dyes, agar, Fuels
Importance
• Algae is easy to grow
• Can produce a high yield of oil
• Oil can be processed into biodiesel
• Help to solve dependence on fossil fuels
• Can be better for the Earth
Integrated with Wastewater
Treatment and CO2 capture
Grown under conditions which are unsuitable for
conventional crop production
(marine water, wastewater, open ponds)
Adaptability to a range of
environment
Historically, The first cars group in the USA operated
on the ethanol fuel (bioethanol).
Then the inventor Dr. Rudolf diesel at 1900 used the
first diesel engine and operated it by peanut oil.
Biodiesel History
Biodiesel History
• From 1978 to 1996 the U.S. Department of Energy funded a program to develop renewable transportation fuels from algae
• The main focus of the program was known as the Aquatic Species Program (or ASP)
• Production of biodiesel from high lipid-content algae grown in ponds
• Utilized waste CO2 from coal fired power plants
Why make it a fuel?
• Algae can be used to make biodiesel• Produces large amounts oil
– When compared to terrestrial crops grown for the same purpose
– Algae contain anywhere between 2% and 40% of lipids/oils by weight
– Once harvested, this oil can be converted into fuels for transportation, aviation or heating
• High growth rate and easy to grow– Warm Seasons
• Amphora sp.• Tetraselmis suecica
– Cold Seasons• Monoraphidium minutum
– Use of diatoms and green algae
Oil Yields of Various Microalgae
Production…
• Oil yield
CropOil Yield
(L/ha/year)
Biodiesel
Productivity
(Kg/ha/year
)
CropOil Yield
(L/ha/year)
Biodiesel
Productivity
(Kg/ha/year
)
Rapeseed 1190 962 Sunflower 952 946
Oil Palm 5950 4747 Jatropha 1892 656
Corn 172 152Microalgae
a58700 51927
Soybean 446 562Microalgae
b136900 121104
a Algae contain 30% oil (/wt) in biomass. b Algae contain 70% oil (/wt) in biomass. Source:
Higher oil yield
0
100
200
300
400
500
600
700
800
900
1000
Soybeans Sunflower Canola Jathropha Palm Oil Microalgae
Oil yields
(barrels/ha-yr)
How to obtain fuel from algae?
• Picking up the best algae
• Growing the algae
• Harvesting
• Generating the fuel product
• Culture and Isolation
• Is isolation a good?
Large-Scale Production
• Ponds
– Less expensive setup
– Large biomass
production
– Evaporation
– Contamination
– Land area
Open systems
Closed systems
Also referred as Photobioreactors
Tubular PBR Flat plate PBR
Closed systems• Photobioreactors
– More controlled
– Limited
contamination
– High biomass
concentration
– Less land area
– Expensive setup
Biodiesel from algae
Cultivation of Microalgae species
Harvesting of Microalgae
Extraction of Oil from Microalgae
Transesterification
Biodiesel
Pressing oil from the algae
• Dry the algae and press the oil from it.
• Can retrieve up to 70% of the oil.
• While drying must prevent the algae from
becoming contaminated.
• Cheapest and simplest method
Chemical Oil Extraction
• Use hexane solvents to remove the oil.
• Hexane is a neurotoxin.
• Must be careful when using.
• Removes oil out of almost all things.
Super Critical Oil Extraction
• Most efficient method.
• Uses carbon dioxide at critical pressure and
temperature (CO2 is almost a liquid).
• Carbon dioxide.
• Rapid diffusion of the oil.
• Very expensive process.
Three ways to produce biodiesel
• Base catalyzed transesterification with
alcohol.
• Acid catalyzed esterification with methanol.
• Enzymes methods
• Convert the oil to fatty acids. Then acid
catalyze to alkyl esters.
Base Catalyzed with Alcohol
• Most common process
• Most economical
• Low pressure (20psi)
• Low temperature (65oC)
• No intermediate steps
• High conversion rate (98%)
Triacylglycerides (TAGs)
• It’s a lipid
• Found in the
membrane and in
the cytoplasm
• High energy
Transesterification
Benefits of Algae Farming
• Year-round production
• Fast biomass production
• Less land area
• Does not compete with food crops
• Higher fuel output
• Can use brackish water
• Carbon neutral
• Algae derived biodiesel could replace fossil fuel
based diesel fuel
• 530 million m3 of biodiesel annually for the
United States
• Oil content of algae can exceed 80% of dry mass
• Oil prices are high
• Should cost about $0.50/L to be competitive with
petroleum diesel, cost about $0.35/L
• Current unrest in the Middle East
Benefits of Algae Farming
National Biodiesel Board 48
US Biodiesel Production
0
100,000,000
200,000,000
300,000,000
400,000,000
500,000,000
600,000,000
700,000,000
Gallo
ns
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
700 Million
Gallons
Growth
• More than 100 companies are working on
algae fuels, especially in USA and UK
0
20
40
60
80
100
120
140
2001 2002 2003 2004 2005 2006 2007 2008 2009
# of companies
Investments
0
100
200
300
400
500
600
700
2006 2007 2008 2009
(in million dollar)
52
Questions?
Thank you …