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International Journal of Marine Science 2013, Vol.3, No.5, 33-35
http://ijms.sophiapublisher.com
34
compressed air, and atomized into small drops near to
the nozzle exit. Viscosity affects the atomization
quality, size of fuel drop and penetration (Hewood,
1988; Lichty, 1967). Density is a key fuel property,
which directly influences the engine performance
characteristics. Many performance characteristics,
such as cetane number and heating value, are analogus
to the density (Tat et al., 2000).
1 Results and Discussions
The importance of microalgae oil production are high
lipid yield and high biomass productivity which can
affect production costs (Rodolfi et al., 2009). So, from
Table 1 the three micro algae used for production of
biodiesel maximum amount of oil were obtained from
Pavlova lutheri
which shows its high lipid content.
There was no significant difference in pH between the
biodiesel produced from these three micro algae. Our
results prove that biodiesel from micro algae contains
much more lipid content than macro algae as in
different reports. In many studies, it was observed that
biodiesel’s density has not changed a lot, because the
densities of methanol and oil are close to the density
of the produced biodiesel (Graboski et al., 1998). So
in our results, the density of biodiesel varies between
0.86 g/cm
3
and 0.90 g/cm
3
. This is depicted in Table 2.
The viscosity values were in the range from 3.92 mm
2
/sec
to 4.5 mm
2
/sec. It is higher than those of the diesel
fuels. The algae are therefore, an economical choice
for biodiesel production because of its availability and
lost cost and capable of meeting the global demand for
transport fuels. Like plants micro algae use sunlight to
produced oils but they do so more efficiently than
crop plants. Therefore, oil productivity of these micro
algae greatly exceeds the oil productivity of the finest
producing oil crops. Further research is going on these
micro algae for biodiesel production, its chemical
analysis and statistical significance.
2 Materials and Methods
2.1 Algae Culture
The algae namely
Isochrysis galbana
,
Pavlova lutheri
,
Dunaliella salina
were procured from CMFRI,
Tuticorin. The algae were cultured in modified
Walney’s medium. The algae were grown under low
illumination up to 50
μ
mol
·
m
-1
·
s
-1
d and unlimited
aerated condition for one week. Temperature was
adjusted to (25±2)
℃
.
Table 1 Measurement of fresh and dry weight, extracted and
biomass of algae
Treatment
of Algae
Fresh
wt/petridish (g)
Dry
weight
Extracted
oil
Biomass
Isochrysis
galbana
25
8.5 g
34.0%
1.99 g
7.96%
3.6 g
Pavlova
lutheri
25
9.2 g
36.8%
2.40 g
9.60%
3.8 g
Dunaliella
salina
25
8.7 g
34.8%
2.19 g
8.76%
4.0 g
Note: Petri dish size was same. Diameter was 7.5 and height 1 cm
Table 2 Density and viscosity analysis of biodiesel
S. No.
Biodiesel from algae
Density
(g/cm
3
)
Viscosity
(mm
2
/sec)
1
Isochrysis galbana
0.872
4.10
2
Pavlova lutheri
0.890
3.92
3
Dunaliella salina
0.877
4.45
Note: mean of n=5 values
2.2 Biodiesel extraction
2.2.1 Oil extraction
Algae were grounded with motor and pestle as much
as possible. The ground algae were dried for 20 min at
80
℃
in a incubator to remove water. Hexane and
ether solution (1:1) were mixed thoroughly with the
dried ground algae to extract oil. Then the mixture
was kept for 24 h for settling.
2.2.2 Biomass extraction
The biomass was collected after filtration and
weighed.
2.2.3 Evaporation
The extracted oil was evaporated in vacuum to release
hexane and ether solutions using rotary evaporator.
2.2.4 Mixing of catalyst with methanol
0.25 g NaOH was mixed with 25 mL methanol and
stirred properly for 20 min.
2.2.5 Biodiesel production
The mixture of catalyst and methanol was poured into
the algal oil in a conical flask. The following reaction
and steps were followed.
2.2.6 Transesterfication
The reaction process is called transesterification