Background Previous Work Optimization of Oleophilic Skimmer Recovery

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 Hydro. Cal 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

Oil properties

Test results Smooth drum 30 rpm 40 rpm Grooved drum 65 rpm

Effect of materials and surface patterns

Preliminary Results from Cold Climate Research on Oil Spills in Ice Arturo A. Keller & Kristin Clark School of Environmental Science & Management, UCSB

Project Objectives q Understand the effect of: l l 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 q Phase 1 (funded by OSRI) l 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 q Phase 2 (funded by MMS) l Field Scale studies • Tests will be conducted at end of Feb at the Cold Regions Research and Engineering Laboratory (NH) • Evaluate Endicott, Hydro. Cal 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 q Overall behavior l l l 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 q Elastomeric materials perform very well for oil recovery q Surface material is important for oil only q As ice % increases, surface material is less important q Wider grooves better for very viscous oils q 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): 7914 -7918 q q http: //www 2. bren. ucsb. edu/~keller/papers/Abstract 68. pdf q 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: //www 2. bren. ucsb. edu/~keller/papers/Abstract 69. pdf q

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 the adhesive properties, but rather on historical price and parameters having major The proposed researchpractice, will help identifying availability. effect on oil adhesion to the recovery surface and select materials that 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 of the experiments curried Results of the experiments carried out with various fresh and evaporated out with Point Mac crude oil, oils and oleophilic plastics and elastomers Preliminary Conclusions • 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. 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