Support : eNewsletters : Eye on Innovation : Issue 1, February 2012

Are nanomaterials the answer to oil spill cleanup?

More than 20 years after the Exxon Valdez disaster in Alaska, there is still no effective technology for removing, recovering and cleaning up oil spills from the surface of sea water and shorelines. Regardless of the cause and the size, oil spills are occurring regularly on all continents.

• A leak during a tanker loading operation led to Nigeria's worst offshore oil spill in more than a decade, dumping more than 40,000 barrels of crude oil. (December, 2011)
• The Greek cargo ship Rena ran aground and broke in two off the coast of New Zealand, spilling hundreds of tons of oil into the sea. (October, 2011)
• An offshore oil spill in the Gannet field of the North Sea, co-owned with Exxon and operated by Shell, dumped 110 tons of oil into the water, causing an oil slick about 20 miles long and 2.5 miles wide. (August, 2011)
• 3,200 barrels of oil and oil-based mud — a substance used as a lubricant in drilling — leaked into Bohai Bay off China's eastern coast, causing longterm environmental damage that is hurting the area's fishing industry. (August, 2011)
• The Deepwater Horizon oil rig went up in flames and hundreds of thousands of tons of crude oil spilled into the Gulf of Mexico near the Gulf coast of the United States. (April, 2010)

These oil spills and others like them continue to raise serious concerns worldwide about the environmental impact of oil tanker accidents at sea or mishaps during the loading and unloading of oil from ships at seaports. Similar concerns are also associated with discharge of oil in areas around oil wells and oil storage facilities. Such oil spills can cause havoc to marine ecology (sea birds, mammals, algae, coral, sea grass etc.), besides the health hazards to the human population located in nearby coastal zones. And, the economic loss resulting from oil spillage suffered by local communities, state and national governments and oil companies is enormous.

Since the 1940s there have been over 60 major oil spills, pouring more than 1.7 billion gallons of oil on sea and land. The top 10 have contributed 1.1 billion gallons. Conventional techniques, such as the following common ones, have not been able to solve the problem of these massive oil slicks:

• use of microorganisms to digest the oil,
• mechanical means like skimmers, booms, pumps, mechanical separators etc.,
• sorbents to remove oil from water through adsorption and/or absorption, and
• use of chemical dispersants like detergents.

Picture credit: NOAA

Sources: Xinhua news agency, Dialog Global Reporter, Business Wire

For more on how these and other conventional methods are used in oil spill clean-up, read the CSA Discovery Guide “Deep Sea Oil Spill Cleanup Techniques: Applicability, Trade-offs and Advantages” from ProQuest.

This issue of Eye on Innovation highlights some recent innovations using nanotechnology and nanomaterials, some spawned by the Gulf coast disaster, to deal with oil spills. We'll conduct our research in Dialog industry and technical sources, including energy, the environment, chemistry and engineering and materials technology, to investigate some of the latest innovations. The Dialog patent collection also helps to identify nanotech solutions scientists are working on worldwide.

What do nanomaterials have to offer?

In recent years a growing interest in nanomaterials and nanotechnology has surfaced worldwide as a potential source of innovation for oil spill cleanup. Some of the world's top scientists and research universities have been working on solutions, some with the help of government funding. For example, immediately following the U.S. Gulf oil spill in 2010, the National Science Foundation (NSF) funded 65 rapid response grants to researchers across the country addressing all aspects of the cleanup. These grants are deployed in times of natural or accidental disasters to quickly engage the world's best scientists and engineers to develop new products or identify alternate uses for current ones.

Patents help forecast what's coming

Patents can often forecast what technologies may be on the horizon. From the Dialog patent collection, we find some solutions that have been proposed and are currently published patents, many of which are nanomaterials of different kinds:

• Aerogels, clays, rice husk
• Nanodispersants made from chemicals
• Magnetic nanocomposites
• Nanowire-based membranes
• Foams and meshes
• Filters and cotton pads
• Carbon nanostructures and carbon nanotube sponges

Often patents are filed and granted for similar processes long before a disaster like the Deep Horizon Gulf oil spill. Scientists and engineers review the prior art and build upon previously granted patents to create inventions that offer more viable ways to provide a solution, for example, a patent granted to Ecomag Technologies Limited in 2004 (Publication No. US 2004/0108276 A1 published on June 10, 2004) and an EP patent in 2007 (Publication No. EP 1303572 B1 published on July 11, 2007). (See Figure 3)

Figure 3 : US Patent 20040108276
U.S. Patents Fulltext database on Dialog

Research institutions, universities and high-tech companies are also sources of potential techniques for oil cleanup.

• Massachusetts Institute of Technology (MIT) researchers have developed absorbent, superhydrophobic nanowire membranes for the selective absorption of oil from an oil-water mixture. They have constructed free-standing membranes comprising inorganic nanowires capable of absorbing oil up to 20 times their weight.
  
  MIT's oil-absorbing robot Sea-swarm uses this nanowire mesh to autonomously navigate the surface of the ocean to collect surface oil and process it on site.
• Swiss high-tech company HeiQ Materials has developed an oil-absorbing, hydrophobic chemical called "Oilguard," a fleece that can soak up six times its own weight in oil and thus provides preventative protection for beaches and coasts during oil spills.
• Invented by an Italian scientist, RECAM^® (REactive CArbon Material)—RE.40 for oil spills—is a new nanostructured carbon. It is hydrophobic, inert, non-flammable, completely stable, and has no negative impacts on the environment. Industrially developed by SA Envitech, which is the brand owner and the first world producer of bulk quantities of nanostructured material, RECAM has passed all the toxicity tests established by the Italian Ministry of the Environment. For large spills RECAM can be distributed across the water creating a barrier that the oil cannot penetrate, and it can be produced on ships ready for immediate use.
• The University of Central Florida devised a micro carbon "octopus" to clean up oil spills. The U.S. Patent 7,691,271 was granted in 2010.

Sources: U.S. Patents Fulltext, CLAIMS/U.S. Patents, Derwent World Patents Index^®

Nanotech viability

Scientists and engineers need to consider a number of issues as they strive for answers to the oil cleanup problem, including environmental, engineering, performance, cost and commercial viability. These materials must contain a variety of characteristics. (See Figure 4)

Opportunities and uncertainties

Nanotechnology offers opportunities for this billion dollar problem; however, there are still some uncertainties to work through. For example, does nanotechnology pose a risk to the environment and human life? Can these risks be overcome? And, will nanotechnology be an effective and economical alternative to current methods of cleaning up the huge number of oil spills worldwide? Points of view differ. These and other questions must be addressed as research on using nanomaterials to clean oil spills continues to emerge.

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