Shell Oil’s ill-fated Arctic oil drilling venture has just been put on hold, and in an epic piece of timing, researchers at the Massachusetts Institute of Technology (MIT) have just proposed a magnet-based method for cleaning up oil spills that could, for the first time ever, link the words “simple,” “fast,” and “energy efficient” with the tedious job of separating oil from water. As an extra sustainability bonus, the cost of the operation could be offset by recycling the harvested oil, and the magnets would be reused, too. The Big Question is, will it work?
Yes, Magnets Could Probably Clean Up Oil Spills
The research team, lead by Shahriar Khushrushahi of MIT’s Department of Electrical Engineering and Computer Science, already has a leg up on the science behind the new method.
To put it mildly, your basic household magnet is not involved. According to MIT writer Larry Hardesty, the new process draws on previous research into magnetic fluids. Also known as ferrofluids, a magnetic fluid contains tiny nano-magnets in suspension.
The idea, quite simply, would be to draw the spilled oil into a ship and mix it with a water repellent ferrofluid. That would effectively magnetize the oil, while any water captured by the operation would remain neutral.
A set of larger magnets would be used to draw off the magnetized oil, which would then be separated from the ferrofluid in another step.
So far, researchers have shown that ferrofluids can be mixed with water and then separated with a high degree of efficiency, but only under controlled conditions.
The challenge for the MIT team was to develop a method that could work under less predictable conditions, where the concentration of oil could vary significantly as the operation progresses.
An Energy Efficient Way to Clean Up Oil Spills
The team has come up with a promising avenue in the form of an array of cylindrical magnets embedded vertically in a reservoir. When a mixture of magnetized oil and water is introduced, beads of oil are forced to the tops of the magnets, which stick out above the water line.
Once exposed, the oil beads can be scooped up by a set of large magnets configured in a Halbach array, which Hardesty describes as a boxy-looking device that produces a stronger magnetic field at one end and a weaker one at the other.
Aside from achieving an “excellent separation,” the process uses less energy than conventional practices. Since it is designed to take place on board a ship, it also reduces the need for energy to transport an oil-and-water mixture to a land site.
More Green Jobs for Magnets
The MIT team still has a long way to go from the lab to the next big oil spill, which hopefully will not come any time soon, though the 30-mile ice sheet drifting toward Shell’s Arctic oil rig doesn’t exactly instill optimism.
In the meantime, magnets are already beginning to play a big role in new clean technology.
One particularly interesting example is the use of magnets in the new generation of high-tech flywheels, adding a 21st century twist to an energy storage device that has been around for hundreds of years.
Yale researchers have been developing a new “liquid magnet” that could serve as a non-toxic soldering compound to replace lead in electronic devices, and Columbia University is partnering with IBM and Cornell University to develop a new energy efficient, magnet-based computer chip.
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Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.