Chemistry Reference
In-Depth Information
oil on the open sea requires an official permission that will be different for
each country. Furthermore, the chemical composition of crude oils as out-
lined in Chapter 2 has the consequence that the strong van-der-Waals in-
teractions between the long alkyl chains give rise to three-dimensional
thick layers. The crude oil has to be pumped from a ship onto the sea sur-
face, where it forms thick layers, dependent on the viscosity of the crude
oil sort or fraction applied. After the campaign, intensive efforts should be
undertaken to recover the remainder of the oil from the sea surface by oil
combating ships.
In order to illustrate the range of application strategies (
chocolate
mousse
,
fuel oil spill
etc.) that are closely related to the chemical structures
of the respective crude oil fractions, examples are summarised in Table 2
that stem from the ARCHIMEDES experiments carried out in the German
Bight in 1983 and 1985 (Commission 1985).
Table 2:
Characteristics of the crude oil fractions used during ARCHIMEDES 1
in 1983 in the German Bight (Commission 1985)
Sort of spill
Fractions
included
Density
>
kg m
-3
@
Viscosity
>
m
2
s
-1
@
Evapora-
tion
>
%
@
fuel oil: 11.3 m
3
gas oil: 4.0 m
3
sea water: 34.7 m
3
# 1 Mousse spill
chocolate
mousse
990
0.0022
(i.e. 2200 cSt)
20
fuel oil: 40.0 m
3
gas oil: 6.7 m
3
#2 Pure fuel oil
spill
895
0.00075
(i.e. 750 cSt)
20
After the combating exercise some samples were taken and analysed: For
spill #1 the viscosity and the water content turned out to be 0.055 m
2
s
-1
and 75 %, respectively, while for spill #2 the viscosity and the water con-
tent attained 0.035 m
2
s
-1
and 70 %, respectively. 18 hours after the spill-
age for both spills a total amount of about 20 m
3
of pure oil was evapo-
rated, and to be combated at the sea surface remained 7.3 m
3
oil in spill #1,
and 28 m
3
fuel oil in spill #2. In total, 30 m
3
were actually recovered by the
combating vessels.
5.2. Comparison of different remote sensors flown over sea
slicks and spills
In the literature, comparison of sensors that were flown over slicks and
spills, which had been produced at different locations, can be found occa-
sionally, and in some few experiments slicks and spills were generated
within the same sea area and overflown with the same sensor systems, be it
air or spaceborne (Table 3).
