HARVESTING MICROALGAE
(CHLAMYDOMONAS REINHARDTII) FOR
BIOFUEL PRODUCTION USING
WASTEWATER TREATMENT TECHNIQUES
By Michael Fuad
Potential of Algae
http://geography.about.com/library/blank/blxusa.htm
Potential of Algae
http://geography.about.com/library/blank/blxusa.htm
Potential of Algae
Complete Process Producing Biofuel
Algae cultures
Photobioreactions
Dried into
algae powder
Processed in
soxhlet, oils
extracted
Harvested into
algae
concentrates
Complete Process Producing Biofuel
Algae cultures
Photobioreactions
Dried into
algae powder
Processed in
soxhlet, oils
extracted
Harvested into
algae
concentrates
Complete Process Producing Biofuel
Algae cultures
Photobioreactions
Dried into
algae powder
Processed in
soxhlet, oils
extracted
Harvested into
algae
concentrates
Complete Process Producing Biofuel
Algae cultures
Photobioreactions
Dried into
algae powder
Processed in
soxhlet, oils
extracted
Harvested into
algae
concentrates
Complete Process Producing Biofuel
Algae cultures
Photobioreactions
Dried into
algae powder
Processed in
soxhlet, oils
extracted
Harvested into
algae
concentrates
Complete Process Producing Biofuel
Algae cultures
Photobioreactions
Harvested into
algae
concentrates
Dried into
algae powder
Processed in
soxhlet, oils
extracted
Esterification
produces
biofuels
What is the problem?
• Algae cost $20.00/gallon of biofuel
• Furthermore, a significant part of that
production cost is associated with harvesting
microalgae
Background
• 10 µm
10 µm
http://algae.tcoalternativefuels.com/wp-content/uploads/2008/05/chlorellasp_microscope.jpg
Background
http://www.steve.gb.com/images/science/centrifugation.png
Background
Alternative Harvesting Methods:
1. Ultrasonic separation—Bosma et al. (2003)
Background
Alternative Harvesting Methods:
1. Ultrasonic separation
2. Froth flotation—Csordas et al. (2004)
Background
Alternative Harvesting Methods:
1. Ultrasonic separation
2. Froth flotation
3. Flocculation
Background
http://globalpolyglu.com/treatment1-2.html
Background
http://globalpolyglu.com/treatment1-2.html
Background
http://globalpolyglu.com/treatment1-2.html
Background
• Water and Wastewater Technology by
Hammer and Hammer (1996) explained
flocculation
Background
• A Lee et al. (2007)—algae are negatively
charged microparticles
Hypothesis
• I hypothesized that chemicals used in
wastewater treatments could be used to
flocculate microalgae
Background
• Knuckey et al. (2006)—identified factors that
affect flocculation, i.e. pH and dosage
Goals
1. Determine if flocculation is an effective
alternative to centrifugation for harvesting
C. reinhardtii from suspension; and
2. Identify factors that optimize flocculation of
C. reinhardtii in order to achieve harvesting
efficiency that is similar to or better than
centrifugation in preparation for biofuel
production.
Procedure
• Measure effectiveness of harvesting by
flocculation using spectrophotometer,
measuring optical density (absorbance)
Materials: Ionic Compounds
1.
2.
3.
4.
Aluminum sulfate—Al2(SO4)3
Ferric chloride—FeCl3
Calcium carbonate—CaCO3
Ammonium sulfate—(NH4)2SO4
Materials: Polyacrylamides
Results
Flocculation Efficiency
Results
1
0.8
0.6
0.4
0.2
pH 7.00
0
pH 3.00
Al2(SO4)3
FeCl3
CaCO3
Ionic Compound
(NH4)2SO4
Flocculation Efficiency
Results
1
0.8
0.6
0.4
0.2
pH 7.00
0
pH 3.00
Al2(SO4)3
FeCl3
CaCO3
Ionic Compound
(NH4)2SO4
Flocculation Efficiency
Results
1
0.8
0.6
0.4
0.2
pH 7.00
0
pH 3.00
Al2(SO4)3
FeCl3
CaCO3
Ionic Compound
(NH4)2SO4
Results: pH 3.00
Flocculation Efficiency
1.00
0.80
0.60
0.40
0.20
0.00
1
2
3
4
5
6
7
8
9
Polyacrylamide Number
10
11
12
13
Results: pH 3.00
Flocculation Efficiency
100%
80%
60%
40%
20%
0%
1
2
3
4
5
6
7
8
9
Polyacrylamide Number
10
11
12
13
Results: pH 3.00
Flocculation Efficiency
100%
80%
60%
40%
20%
0%
1
2
3
4
5
6
7
8
9
Polyacrylamide Number
10
11
12
13
Conclusions
• Flocculation effectively harvests microalgae
• The optimum flocculation technique is to use
Clarifloc Polyacrylamide C-6288 at a pH of
3.00 and a dosage of 0.025 g flocculant/g dry
algae
• Since flocculation is more efficient than
centrifugation, flocculation is a less expensive
method of harvesting microalgae
Limitations
• My research limited to a single species of
algae
• Flocculation factors might vary for different
algae species
• Effect of chemicals on environment is
experimentally unknown. However,
theoretically, flocculation is safe for
environment
Future Work
• Engineer a continuous
flocculation system
• Apply the flocculation
techniques to other
microalgae species
with potential
http://brator.sinto.co.jp/global/picture/dspirast.jpg
Acknowledgements
•
•
•
•
Dr. Roger Ruan
Science Research Team
Mrs. Fruen
Mr. Hall
http://www.bioeconomyconference.org/07%20Images/ruan.jpg
HARVESTING MICROALGAE
(CHLAMYDOMONAS REINHARDTII) FOR
BIOFUEL PRODUCTION USING
WASTEWATER TREATMENT TECHNIQUES
By Michael Fuad