Fig 3 Relation between viscosity and temperature
3.3 Procedure
The test procedure adopted in the tests is Japanese test standard Hakusa 52.
Environmental temperature for the tests was 25℃, at which the oil viscosity was
l0.000cSt .
3.4 Results and consideration
Tests on various combinations of surfactants with solvents were carried out. Surfactant
N0.1 which produced the highest dispersion rate, is shown in Table5b and Fig.4b.The result
of surfactant N0.2 which produced the lowest dispersion rate is given in Table5b and
Fig.4b.
In comparison of surfactant N0.1 to N0,2 in terms of solventA, dispersion rate of No.1
after a settling time of 30 seconds was considerably high; while the rate of N0.2 after a
settling t[me of 30 seconds was relatively low. After 10 minutes, surfactant No.l showed
76.596 while surfactant N0.2 showed only 16.2% which does not attain the threshold of
Japanese test standard.
Stability rate can be determined with the following formula,
The stability rate for surfactant No.1 is 76.7% while the stability rate for surfactant
N0.2 is 20.496. Surfactant N0.1 is 3.8 times as stable as surfactant N0.2.
Kenneth.W.Becker*' and his co-workers achieved dispersibility tests using a single
dispersant and five different crude oils. They reported that the dispersion rate for the
dispersant on crude oils in the tests ranges from 50% to 95% .
This suggests that the effective dispersant for a certain oil should be selected
depending on the properties of the oil, such as specific gravity, viscosity, pour points
and composition of the oil, because the effectiveness of a single dispersant cannot be
predicted for every kind of oil.
As a result of test using a wide range of combination between surfactants and solvents,
five surfactants and six solvents were determined likely to be amenable to high-viscosity
oils. From now on, various tests will be done on different oils with various viscosities
to develop dispersants for high-viscosity oils by using these surfactants and solvents.
Table5a Surfactant with high dispersion rate(No.1)
| |
Dispersion rate(%） |
| solvent |
30sec.settling |
10min.settling |
| A |
99.8 |
76.5 |
| B |
99.2 |
72.5 |
| C |
99.5 |
82.6 |
| D |
98.3 |
64.6 |
| E |
98.4 |
70.9 |
| F |
91.3 |
50.3 |
| G |
56.6 |
30.4 |
| H |
51.9 |
12.7 |
| I |
66.5 |
31.9 |
| J |
61.3 |
21.6 |
Table5b Surfsactsnt with low dispersion rate(No 2)
| |
Dispersion rate(%） |
| solvent |
30sec.settling |
10min.settling |
| A |
79.6 |
16.2 |
| B |
80.5 |
16.0 |
| C |
91.4 |
13.7 |
| D |
78.5 |
14.4 |
| E |
77.6 |
14.1 |
| F |
66.2 |
11.5 |
| G |
37.6 |
15.3 |
| H |
36.7 |
16.0 |
| I |
36.2 |
12.7 |
| J |
35.8 |
13.3 |
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