Biodiesel From Microalgae
Lipid synthesis in microalgal cultures
Shuo Yao
Jingquan Lu
Anders Brandt
Claes Gjermansen
Klaus Breddam
•
Algal
physiology
and
lipid
synthesis
•
Large
scale
growth
•
Harvesting
•
Extraction
•
Processing
Oil
yield
l/ha/year
Soybean
400
Sunflower
1000
Jathropha
2000
Oil
Palm
6000
Algae
9000
Commercial product
Market size
t/year
Sales volume million
$US/year
Biomass
Health Food
7000
2500
Aquaculture
1000
700
Animal feed
300
Polyunsaturated FA
ARA
20
DHA
300
1500
PFFA Extracts
10
Antioxidants
beta-Carotene
1200
280
Tocopherol
100
Coloring substances
Astaxantin
300 (bm)
150
Phycocyanin
10
Phycoerythrin
2
Ferilizars/soil conditioners
5000
5572
Ref:Pulz and Gross (2004),
Spolaore et al (2006),Metting and
Pyne (1986)
Algal
Oil
production
Costs
Can
Be
Reduced
by
Integration
with
Algal
Oil
production
Costs
Can
Be
Reduced
by
Integration
with
Wastewater
Treatment
Wastewater
Treatment
Inspired by T.J. Lundquist, I.C. Woertz, N.W.T. Quinn, and J.R. Benemann:
A Realistic Technology and Engineering Assessment of Algae Biofuel
www.cehmm.org
•
Water
quality
•
Species
control;
robust
local
strains
•
Low
‐
cost
harvesting
•
Biomass
with
high
lipid
content
•
Productivities
near
the
efficiency
limits
of
photosynthesis
Figure 1-1. Commercial microalgae production in open raceway paddle wheel mixed
ponds.
Left: Earthrise Nutritionals, LLC, California. Spirulina production, Ponds ~ 1 acre.
Right: Cyanotech Co., Hawaii, producing Haematococcus pluvialis (red ponds) and Spirulina.
The production facilities on which some of the assumptions are based
Figure 1-2. Test facility for algae biomass production integrated with wastewater
treatment
Left: High Rate Ponds at Univ.of California, Berkeley.
~100,000 species; fresh and sea water
Silica cell walls
Store carbon as Lipids
Diatoms
Green algae
~8,000 species; fresh and sea water
Store carbon as Starch
Accumulate lipids upon stress
Algal
species
A few thousand strains are kept in culture
collections throughout the world,
A few hundred are being investigated for
their chemical content and
A handful are cultivated on an industrial
scale.
Challenges
•
Why so few?
•
Difficult to domesticate
•
Difficult to scale up from laboratory to large-scale cultivation
•
Low harvest efficiency
•
Production costs
Laboratory scale, max 2 litre
Algae
species
Salt water
Dunaliella sp
Brackish water
Nannochloropsis sp (constitutive lipid synthesis)
Fresh water
Chlorella sp
Chlamydomonas sp
Neochloris sp (constitutive lipid synthesis)
Haematococcus sp
Algal Lipids
Acyl lipids
Non-acyl lipids
Polar lipids
Non-polar lipids
Phospholipids
Glycolipids
(isoprenoids, carotenoids)
•
Cell size.
(C. reinhardtii can range from 2
μ
m diameter to 12
μ
m in haploid wild type to twice this size in
diploid strains)
•
Cell number.
Mitotic doubling rate;
Cells per unit culture is determined by the density at which the cells shift into stationary phase.
Little is known about why algae go into stationary phase at species-specific cell densities;
Depletion of nutrients, buildup of toxic components in the media, quorum effects, and/or other
genetic constraints.
Triacyl
glycerides
(TAG)
yield
‐
Two
parameters
to
manipulate
Risø DTU, Danmarks Tekniske Universitet
