Smart Coating Could Clean Oil Spills
MONDAY, MAY 19, 2014
A new coating that instantly separates oil from water offers significant promise in cleaning up major oil spills and reducing the massive water demands of fracking, researchers say.
Unlike clay, straw, wool and other absorbents that are traditionally used to soak up oil spills (and much of the water that surrounds them), the new coating removes the oil from the water, say developers at Durham University in the UK.
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One month after the Deepwater Horizon exploded in the Gulf of Mexico in April 2010, NASA Terra satellites captured the oil slick from space. The record spill dumped about 4.9 million barrels of oil. Cleanup was slow and cost billions. |
The coating can yield oil-water mixture separating efficiencies of more than 98 percent, the scientists say.
Panning for ... Oil?
The process evokes the Hollywood version of panning for gold. The researchers developed oleophobic-hydrophilic (oil repelling, water attracting) coatings that they then applied to pieces of steel mesh, such as those used in screen doors, according to a research announcement.
When an oil-water mixture was poured through the mesh, the water dripped through while the oil remained "perched" on top, said the team led by Dr. J.P.S. Badyal. When the mesh was tilted, the oil could be easily poured off into a collection container.
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Coated mesh holds the oil on top while the water "instantaneously" separates and drips through, the team said. |
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"The separation was instantaneous and more efficient than existing films, and it only took one step to make the coating," according to the announcement by the American Chemical Society, which has just published the research.
"The team also demonstrated that it could serve as an anti-fogging and self-cleaning film."
Fracking Potential
The technology could also be used to reduce and reuse some of the copious amounts of water used in hydraulic fracturing (fracking), the team says.
With fracking, a liquid (usually water) is injected into the wellbore to create fractures that are then held open with sand or other proppants while oil and gas are released from the shale. A 2011 report by the U.S. Environmental Protection Agency estimated that 70 to 140 billion gallons of water are used to fracture 35,000 U.S. wells each year.
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Fracking operations, like this one at North Dakota's Bakken Formation in 2011, use billions of gallons of water each year. Researchers say their new coating could help reduce that demand.   |
Fracking critics denounce the process's huge consumption of fresh water, its contamination of ground water, and the attendant resource drain caused by transporting, filtering, distilling and recycling wastewater.
Cleaner Surfaces
The technology could also stop surfaces from getting foggy and dirty, the team writes in "Ultrafast Oleophobic-Hydrophilic Switching Surfaces for Antifogging, Self-Cleaning, and Oil-Water Separation," which was published April 30 in ACS Applied Materials & Interfaces.
The research was funded in part by the Engineering and Physical Sciences Research Council.
Tagged categories: Coating Materials; Fracking; Oil and Gas; Pipeline; Research; Smart coatings
