Gulf Clean-up: Breaking down oil with surfactants
Cleantech Chemistry will save for later the discussion of whether the environmental disaster in the Gulf of Mexico will put more attention on replacing petroleum in the U.S. economy. But in the meantime it is interesting to note the contribution that chemistry is making to clean-up efforts.
Water treatment firm Nalco released a statement confirming that it is supplying quantities of oil dispersants for the Gulf operation, but did not elaborate on how much of it the company was selling. Nevertheless, the announcement prompted Nalco’s stock to rise 18% to $29.25, hitting its highest point since October 2007. In the press release, Nalco thanks its suppliers for stepping up to the plate, which suggests the company is selling its dispersant as fast as it can be manufactured.
Though Nalco has not yet responded to a request for an interview, the company’s website describes its Corexit dispersant technology as designed specifically to protect and clean shorelines affected by oil spills at sea. The product is made with bio-degradable surfactants in a low-toxicity, de-aromatized hydrocarbon solvent system.
If the chemical dispersant works as designed, the solvent system distributes the surfactants into the oil slick. Then the surfactants go to work reducing the surface tension at the oil/water interface. With the oil film’s cohesion lessened, the action of the waves helps to break up the slick into small droplets of oil. The small drops sink from the surface of the sea and are further degraded by the ocean’s native bacteria.
BP CEO Tony Hayward has been reported as claiming the dispersants have had a significant impact keeping the oil from floating to the surface, but there is very little detail available about how successful the chemical treatment has been so far.
In addition to Nalco, other producers of dispersants include BP, Croda, Dasic International, INEOS Chemical, Shell, Taiho, Total, and U.S. Polychemical, writes Laurence Alexander, chemicals analyst at Jefferies & Company. Alexander has been tracking reports that the operation is requiring around 10,000 gallons of dispersants a day.