40th Leeds-Lyon Symposium on Tribology & Tribochemistry Forum 2013
September 4-6, 2013, Lyon, France
High Pressure Behavior of Oil Extracted from Green Alga Botryococcus braunii
B. Zhang1*, T. Mawatari1, N. Ohno1, K. Tajima1
M. Ozeki2, H. Kuno2, S. Bunne2, H. Fukuda2, M. M. Watanabe3
1)
Graduate school of science and engineering, Saga University, 1 Honjo-machi, Saga-shi, Saga 840-8502, Japan.
2)
Denso corporation, 1-1 Showa-cho, Kariya-shi, Aichi 448-8661, Japan.
3)
University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
*
Corresponding author: [email protected]
Table 1 Viscosity at atmosphere pressure and pressure
viscosity coefficient of typical natural oils
Dyn. Visc.
Pres. Visc. Coeff.
mm2/s
GPa-1
40°C
100°C
20°C
40°C
B. braunii
13.8
3.5
21.0
14.6
Squalene
9.9
3.2
13.2
11.9
Squalane
18.6
6.1
16.9
(11.3)
PAO17
17.1
4.0
12.8
11.1
100
Liquid
50
:Botryococcus test results
:Botryococcus
:PAO32
:Squalane
:Squalene
T , °C
Abstract
Green alga Botryococcus braunii is regarded as a
potential source of bio-diesel fuel because of its ability
to produce large amounts of hydrocarbons and its
widespread in the world. One of the most potential oil
extracted from green alga B. braunii was investigated
for its rheological behavior and state transition under
high pressure at different temperatures. The results were
compared with that of other natural oils such as squalene
and squalane.
0
Solid
-50
0
0.5
1.0
P, GPa
Fig.2 Phase diagram of B. braunii oil together with that
of squalane, squalene and PAO32.
Figure 2 shows that B. braunii oil has a very similar
behavior to that of PAO32 and squalene, except that the
liquid-to-solid transition temperature is a little higher
than that of both PAO32 and squalene.
104
10
8
Botryococcus
Temperature
:265.6K,
:269.3K,
Viscosity , Pa·s
Bulk modulus K, GPa
12
:283K
:293K
6
4
102
101
0.2
0.4
0.6
0.8
Pressure P, GPa
1
Fig.1 Dependence of bulk modulus of B. braunii oil on
pressure at different temperatures
Figure 1 shows that the bulk modulus of B. braunii oil
increases almost linearly with pressure until a critical
pressure. When the pressure exceeded the critical value
the increase in the bulk modulus was accelerated. This
critical pressure is the liquid-to-solid transitional
pressure of the oil.
Botryoccoccus,
Experiment
:273K,
:293K
:313K,
:333K
Predictive equation
Sorab+Free Volume
:273K,
:293K
:313K,
:333K
100
10-1
10-2
10-3
0
2
0
103
200
400
600
800 1000
Pressure P, MPa
Fig.3 Dependence of viscosity on pressure at different
temperatures for B. braunii oil
The viscosity of the B. braunii oil increases with the
pressure at the all experimental temperatures, and the
dependence of viscosity on both pressure and
temperature may be expressed approximately by the
Sorab and the free volume equations, of which the
results are also given in Fig. 3.