Optimization of Oleophilic Skimmer Optimization of Oleophilic Skimmer

Recovery SurfacesRecovery Surfaces

Victoria Broje and Arturo A. KellerVictoria Broje and Arturo A. Keller

School of Environmental Science and School of Environmental Science and Management University of California Santa Management University of California Santa

Barbara Barbara

MMS ROTEC meeting, September 2006MMS ROTEC meeting, September 2006

Background- Previous Work

Surface textures Surface textures

10 m 10 m

Neoprene Steel LD

polyethylene

10 m

Effect of surface pattern on the Effect of surface pattern on the recovery efficiencyrecovery efficiency

Surface pattern Surface pattern

U.S. Provisional Patent Application (serial no. 60/673,043) by UCSB.

Surface patterns Surface patterns

Test variables 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 Surface patterns

Comparison of patterned surfaces

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0 5 10 15 20 25

time (s)

mas

s w

ithd

raw

n (g

)

.

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0 5 10 15 20 2530 degrees groove

60 degrees groove

90 degrees groove

Large diameter

Small diameter

Flat surface notcorrected for the drop

Flat surface corrected forthe drop

Oil propertiesOil properties

Test results Test results

Smooth drum Grooved drum30 rpm 40 rpm 65 rpm 65 rpm

Effect of materials and surface patterns Effect of materials and surface patterns

Recovery efficiency vs. drum rotation speedEndicott crude - 25 mm slick

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

25.00 35.00 45.00 55.00 65.00

drum rotation speed (rpm)

reco

very

effic

ienc

y (g

pm)

. Neoprene smooth

sheet

Polypropylenesmooth sheet

Neoprene smoothcoated

Polyethylene smooth

Aluminum smooth

Aluminum grooved

Neoprene grooved

Preliminary Results from Preliminary Results from Cold Climate Research on Cold Climate Research on

Oil Spills in IceOil Spills in Ice

Arturo A. Keller & Kristin ClarkArturo A. Keller & Kristin ClarkSchool of Environmental Science & School of Environmental Science &

Management, UCSBManagement, UCSB

Project ObjectivesProject Objectives

Understand the effect of:Understand the effect of: Cold temperatures on recovery of viscous oils Cold temperatures on recovery of viscous oils

by smooth and grooved skimmer drumsby smooth and grooved skimmer drums Mixture of slush ice and oil on the recovery Mixture of slush ice and oil on the recovery

process process Material and roughness of recovery unit on oil Material and roughness of recovery unit on oil

withdrawal and slip conditionwithdrawal and slip condition Drum rotation speed on the adhesion Drum rotation speed on the adhesion

process, amount of recovered oil and process, amount of recovered oil and recovered free waterrecovered free water

Project PhasesProject Phases

Phase 1 (funded by OSRI)Phase 1 (funded by OSRI) Lab Scale studiesLab Scale studies

• Physicochemical properties of oils at and below Physicochemical properties of oils at and below freezingfreezing

• Physicochemical properties of oil/ice mixturesPhysicochemical properties of oil/ice mixtures• Oil recovery by various materials for oil/ice Oil recovery by various materials for oil/ice

mixturesmixtures• Evaluation of different recovery geometries Evaluation of different recovery geometries

(groove angle/depth) to increase oil recovery in the (groove angle/depth) to increase oil recovery in the presence of icepresence of ice

Test setup Test setup

Project PhasesProject Phases

Phase 2 (funded by MMS)Phase 2 (funded by MMS) Field Scale studiesField Scale studies

• Tests will be conducted at end of Feb at the Cold Tests will be conducted at end of Feb at the Cold Regions Research and Engineering Laboratory Regions Research and Engineering Laboratory (NH)(NH)

• Evaluate Endicott, HydroCal and diesel recovery at Evaluate Endicott, HydroCal and diesel recovery at freezing temperatures, with and without slush icefreezing temperatures, with and without slush ice

• 6 skimmer drums (4 materials, 3 geometries)6 skimmer drums (4 materials, 3 geometries)• Evaluation of drum rotational speed on overall Evaluation of drum rotational speed on overall

recoveryrecovery

Preliminary ResultsPreliminary Results

Overall behaviorOverall behavior Density decreases as ice % (by weight) Density decreases as ice % (by weight)

increasesincreases Surface tension and viscosity behavior is Surface tension and viscosity behavior is

strongly dependent on oil typestrongly dependent on oil type Higher viscosity at cold temperatures Higher viscosity at cold temperatures

increases adhesion, but some mixtures increases adhesion, but some mixtures practically don’t flowpractically don’t flow

Preliminary ResultsPreliminary Results60% Ice in Hydro Cal Mixture Ice and Endicott Mixture

Preliminary ResultsPreliminary Results

Elastomeric materials perform very well for Elastomeric materials perform very well for oil recoveryoil recovery

Surface material is important for oil onlySurface material is important for oil only As ice % increases, surface material is As ice % increases, surface material is

less importantless important Wider grooves better for very viscous oilsWider grooves better for very viscous oils Narrower grooves will be evaluated for Narrower grooves will be evaluated for

light petroleum products (e.g. diesel)light petroleum products (e.g. diesel)

Links to publications of previous Links to publications of previous workwork

V. Broje and A. A. Keller. 2006. Improved Mechanical OilV. Broje and A. A. Keller. 2006. Improved Mechanical Oil Spill 1 Recovery Using an Optimized Geometry for the S Spill 1 Recovery Using an Optimized Geometry for the Skimmer Surface. Environ. kimmer Surface. Environ. SciSci. Tech. 40(23):7914-7918 . Tech. 40(23):7914-7918    

   http://www2.bren.ucsb.edu/~keller/papers/Abstract68.pdfhttp://www2.bren.ucsb.edu/~keller/papers/Abstract68.pdf

V. Broje and A. A. Keller. 2007. Interfacial interactions beV. Broje and A. A. Keller. 2007. Interfacial interactions between hydrocarbon liquids and solid surfaces used in metween hydrocarbon liquids and solid surfaces used in mechanical oil spill recovery. J. Colloid & Interface Science, chanical oil spill recovery. J. Colloid & Interface Science, 305:286–292, doi:10.1016/j.jcis.2006.09.078 305:286–292, doi:10.1016/j.jcis.2006.09.078     http://www2.bren.ucsb.edu/~keller/papers/Abstract69.pdfhttp://www2.bren.ucsb.edu/~keller/papers/Abstract69.pdf

  

Advanced Oil Spill Recovery in Marine Environments

Victoria Broje and Arturo A. KellerBren School of Environmental Science and Management,

University of California, Santa Barbara

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.

The proposed research will help identifying parameters having major effect on oil adhesion to the recovery surface and select materials that have the highest oil recovery rate.

Preliminary Results

Force acting on test surface = weight of the plate – buoyancy force + surface tension.

RoughnessRoughness SmoothSmooth(< 10 nm)(< 10 nm)

Low Low roughnessroughness

(20 (20 m)m)

High High roughness roughness

(50 (50 m)m)

Advancing contact Advancing contact angleangle 333311 282811 222211

Recovered mass (mg)Recovered mass (mg) 55 88 1010

0.2 mm

Research Method

Preliminary Conclusions

Effect of material roughness on oil adhesion

Results of the experiments carried out with Point Mac crude

oil, plastics and elastomers

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.

• 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.

• 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.

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.

Advancing contact angle vs. recovered mass

R2 = 0.9705

R2 = 0.9263

R2 = 0.9655

R2 = 0.9314

R2 = 0.9847

0

5

10

15

20

25

30

0.7500 0.8500 0.9500 1.0500

cos of advancing angle

Point Mac

Hydrocal

Cook's inlet

IFO 120

Cook's inlet15 % weightlossPoint Mac 15% weightloss

Contact angle hysteresis vs. recovered mass

R2 = 0.9377

R2 = 0.8476

0

5

10

15

20

25

30

35

40

78.0 80.0 82.0 84.0 86.0 88.0 90.0

contact angle hysteresis

PlasticsElastomers

Results of the experiments curried out with various fresh and

evaporated oils and oleophilic plastics

Introduction

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).

Existing mechanical recovery Existing mechanical recovery equipment:equipment: Shapes of the recovery unit: mop, Shapes of the recovery unit: mop, belt, brush, disc, and drum. belt, brush, disc, and drum. Materials of the recovery surface: Materials of the recovery surface: steel, aluminum, and general-use steel, aluminum, and general-use plastics (polyethylene and plastics (polyethylene and polypropylene)polypropylene) Material selection has not been Material selection has not been based on the adhesive properties, but based on the adhesive properties, but rather on historical practice, price and rather on historical practice, price and availability. availability.