Winning Skimming Technology Developed in School Lab

An innovative piece of oil-spill recovery equipment that evolved from a design created by a UC Santa Barbara PhD student and her faculty advisor has won the USD1 million top prize in the 2011 Wendy Schmidt Oil Cleanup X CHALLENGE. The winning prototype in the X CHALLENGE was entered by Elastec/American Marine and shares technology developed at the Bren School of Environmental Science & Management, USA. 

 

While working in the laboratory of her advisor, Professor Arturo Keller, Victoria Broje, a Russian-born physicist-turned-oil-spill-expert redesigned the standard drum oil skimmer, which is a cylinder coated with an oil-adhering material, typically polyethylene or polypropylene. The rotating drum is mounted in a rack and moved through the water on its side, lifting a thin film of oil as it goes. The oil is then scraped from the drum and collected.

 

In her substantially higher-performing skimmer, Broje introduced a "stickier" surface coating. But the real breakthrough came when she enhanced the drum by adding grooves running in the direction of rotation. The grooves add surface area, enhance oil adhesion, and can be cleaned thoroughly with a scraper that fits precisely into them, eliminating the need for brushes.

 

The design was patented, and a few months before Broje received her PhD, UC Santa Barbara completed negotiations to license the patent for the technology to Elastec/American Marine, the largest maker of oil-spill recovery equipment in the United States. Having made her mark on the technology, after graduating, Broje accepted a position as an oil-spill response expert for Shell Oil, which keeps her busy travelling the world to improve oil-spill preparedness and response.

 

For the X CHALLENGE, five years after licensing Broje's skimmer, Elastec introduced a skimmer that took the grooved design to a new level. The new skimmer incorporates 16 rotating discs spaced evenly along an axle. The discs have concentric grooves on both sides to capture the oil, giving each disc surface area equivalent to that of a single drum skimmer. The entire set-up includes four of the cylindrically shaped 16-disc units arranged one behind the other, so that the skimmer has an oil-recovery capacity equal to that of 64 drums.

 

Every X CHALLENGE sets performance standards well beyond what is considered possible at the time the challenge is issued. The industry standard for oil recovery on the ocean surface, for instance, is about 1,100 gallons per minute; for the X CHALLENGE, the minimum prize-worthy recovery level was set at 2,500 gal/min with a 70% efficiency rate, meaning that the recovered liquid could contain no more than 30% water.

 

Elastec/American Marine's winning entry shattered that "impossible" standard. The new grooved-disc skimmer recovered a 4,670 gal/min, nearly double the X CHALLENGE goal and more than three times the industry's previous best oil recovery rate in controlled conditions, with 89.5% efficiency. It was also nearly twice the recovery rate of the second-place finisher. A third-place prize was not awarded because none of the other teams met the minimum challenge recovery rate.

 

The new skimmer discs were mounted in a specially designed frame that could remain intact while being towed through waves at a minimum speed of one knot, another rigorous X Challenge element, since, according to Elastec CEO Donnie Wilson, a skimmer in a containment boom usually fails when being towed at three-quarters of a knot.

 

Inside the frame, the discs were gulping oil from the tank so fast, thanks to their grooved design, that the collecting tank was overflowing.