Background- Previous Work
Optimization of Oleophilic Skimmer
Recovery Surfaces
Victoria Broje and Arturo A. Keller
School of Environmental Science and
Management University of California Santa
Barbara
Surface textures
10 m
Neoprene
10 m
Steel
10 m
LD polyethylene
Effect of surface pattern on the
recovery efficiency
Surface pattern
U.S. Provisional Patent
Application (serial no.
60/673,043) by UCSB.
Surface patterns
Test variables
• Oil type (Diesel, Endicott – Alaskan crude oil, and HydroCal
300 lubricant oil);
• Oil film thickness (10 mm, 25 mm and 50 mm);
• Drum rotation speed (30, 40 and 70 rpm);
• Air temperature (10-15ºC and 25-30ºC);
• Material of the recovery surface (Aluminum, Polyethylene,
Polypropylene, Neoprene, Hypalon);
• Pattern of the recovery surface (smooth or grooved).
Surface patterns
Comparison of patterned surfaces
Comparison of patterned surfaces
mass
withdrawn
(g)(g) . .
mass
withdrawn
0
0
-0.2
-0.2
0
0
5
5
10
10
15
15
20
20
25
25
30 degrees groove
30 degrees groove
60 degrees groove
60 degrees groove
-0.4
-0.4
90 degrees groove
90 degrees groove
-0.6
-0.6
Large diameter
Large diameter
-0.8
-0.8
Small diameter
Small diameter
-1
-1
-1.2
-1.2
time (s)
time (s)
Flat surface not
Flat
surface
corrected
for not
the drop
corrected for the drop
Flat surface corrected for
Flat
surface corrected for
the drop
the drop
Oil properties
Test results
Smooth drum
30 rpm
40 rpm
Grooved drum
65 rpm
65 rpm
Effect of materials and surface patterns
Recovery efficiency vs. drum rotation speed
Endicott crude - 25 mm slick
recovery efficiency (gpm) .
9.00
8.00
Neoprene smooth
sheet
Polypropylene
smooth sheet
Neoprene smooth
coated
Polyethylene smooth
7.00
6.00
5.00
4.00
3.00
Aluminum smooth
2.00
Aluminum grooved
1.00
0.00
25.00
Neoprene grooved
35.00
45.00
55.00
drum rotation speed (rpm)
65.00
Preliminary Results from
Cold Climate Research on
Oil Spills in Ice
Arturo A. Keller & Kristin Clark
School of Environmental Science &
Management, UCSB
Project Objectives
 Understand




the effect of:
Cold temperatures on recovery of viscous oils
by smooth and grooved skimmer drums
Mixture of slush ice and oil on the recovery
process
Material and roughness of recovery unit on oil
withdrawal and slip condition
Drum rotation speed on the adhesion
process, amount of recovered oil and
recovered free water
Project Phases
 Phase

1 (funded by OSRI)
Lab Scale studies
• Physicochemical properties of oils at and below
freezing
• Physicochemical properties of oil/ice mixtures
• Oil recovery by various materials for oil/ice
mixtures
• Evaluation of different recovery geometries
(groove angle/depth) to increase oil recovery in the
presence of ice
Test setup
Project Phases
 Phase

2 (funded by MMS)
Field Scale studies
• Tests will be conducted at end of Feb at the Cold
Regions Research and Engineering Laboratory
(NH)
• Evaluate Endicott, HydroCal and diesel recovery at
freezing temperatures, with and without slush ice
• 6 skimmer drums (4 materials, 3 geometries)
• Evaluation of drum rotational speed on overall
recovery
Preliminary Results
 Overall



behavior
Density decreases as ice % (by weight)
increases
Surface tension and viscosity behavior is
strongly dependent on oil type
Higher viscosity at cold temperatures
increases adhesion, but some mixtures
practically don’t flow
Preliminary Results
60% Ice in Hydro Cal Mixture
Ice and Endicott Mixture
Preliminary Results
 Elastomeric
materials perform very well for
oil recovery
 Surface material is important for oil only
 As ice % increases, surface material is
less important
 Wider grooves better for very viscous oils
 Narrower grooves will be evaluated for
light petroleum products (e.g. diesel)
Links to publications of previous
work



V. Broje and A. A. Keller. 2006. Improved Mechanical Oil
Spill 1 Recovery Using an Optimized Geometry for the
Skimmer Surface. Environ. Sci. Tech. 40(23):79147918
http://www2.bren.ucsb.edu/~keller/papers/Abstract68.pdf
V. Broje and A. A. Keller. 2007. Interfacial interactions
between hydrocarbon liquids and solid surfaces used in
mechanical oil spill recovery. J. Colloid & Interface
Science, 305:286–292,
doi:10.1016/j.jcis.2006.09.078 http://www2.bren.ucsb.e
du/~keller/papers/Abstract69.pdf

Advanced Oil Spill Recovery in Marine Environments
Victoria Broje and Arturo A. Keller
Bren School of Environmental Science and Management,
University of California, Santa Barbara
Introduction
Almost 14,000 oil spills are
reported each year in the United
States alone. Immediate
response to the release using
efficient recovery techniques
can significantly reduce
environmental impacts and
decrease the cost of the clean
up.
Existing mechanical recovery
equipment:
 Shapes of the recovery unit: mop,
belt, brush, disc, and drum.
 Materials of the recovery surface:
steel, aluminum, and general-use
plastics (polyethylene and
polypropylene)
 Material selection has not been
based
on theresearch
adhesive
but parameters having major
The
proposed
willproperties,
help identifying
rather on historical practice, price and
effect
on oil adhesion to the recovery surface and select materials that
availability.
have the highest oil recovery rate.
Research Method
A Dynamic Contact Angle Analyzer was used for
evaluation of candidate materials and selection of materials
that can be most efficiently used for oil spill cleanup.
Contact Angle () is an angle formed between an
oil film and test surface. The difference between
advancing and receeding contact angles is called
the contact angle hysteresis.
Contact angles can be estimated by measuring the force
acting on the test surface while it is advancing and
receeding through oil.
Force acting on test surface = weight of the plate –
buoyancy force + surface tension.
Preliminary Results
Results of the experiments curried
out with various fresh and
evaporated oils and oleophilic plastics
25
Point Mac
40
35
R2 = 0.9705
Hydrocal
20
• The contact angle hysteresis was found to be proportional to the ability of
a material to recover oil.
• Several materials have been identified as having high oil recovery potential
under dry or water wet conditions.
• Oil composition and surface roughness of test material was found to have a
significant effect on the results of the adhesion tests. Higher roughness results
in lower contact angle and larger recovered mass, for the same oil-polymer
pair.
Contact angle hysteresis vs. recovered mass
Advancing contact angle vs. recovered mass
30
Preliminary Conclusions
Results of the experiments
carried out with Point Mac crude
oil, plastics and elastomers
Cook's inlet
30
25
R2 = 0.9377
Plastics
Elastomers
20
15
2
R = 0.9847
10
R2 = 0.9314
R2 = 0.9263
5
R2 = 0.9655
0
0.7500
IFO 120
0.8500
0.9500
cos of advancing angle
1.0500
15
R2 = 0.8476
10
Cook's inlet
15 % weight
loss
Point Mac 15
% weight
loss
5
0
78.0
80.0
82.0
84.0
86.0
88.0
90.0
contact angle hysteresis
Effect of material roughness on oil adhesion
0.2 mm
Acknowledgements
This research has been funded by the University of California Toxic
Substances Research & Teaching Program and the US Department of the
Interior (Mineral Management Service).
Roughness
High
roughness
(50 m)
Smooth
(< 10 nm)
Low
roughness