Public Release: 

Brookhaven lab and caithness operating company win R&D 100 Award for a technology to recover silica from geothermal brine

DOE/Brookhaven National Laboratory

UPTON, NY - The U.S. Department of Energy's Brookhaven National Laboratory, in collaboration with Caithness Operating Company of Reno, Nevada, won a 2001 R&D 100 Award for developing a technology to recover commercial-quality silica from geothermal brine, a byproduct of geothermal energy production. Retrieving this valuable product from brine, which is generally disposed of as waste, results in cheaper energy production.

R&D 100 Awards are given annually by R&D Magazine to the top 100 technological achievements of the year. Typically, these are innovations that transform basic science into useful products. The awards will be presented at Chicago's Museum of Science & Industry on October 4.

Secretary of Energy Spencer Abraham said, "I'm proud of the award-winning work done at the department's Brookhaven National Laboratory. This accomplishment demonstrates the value of government-funded research to the nation."

According to "Renewable and Sustainable Energy Reviews"(Volume 1, 1997), about 0.4 percent of the world's electricity is derived from geothermal energy. Also, some areas of the world, including parts of the western U.S., use geothermal energy for heat. The new technology recovers silica from geothermal brine, reducing maintenance costs of geothermal energy production. The notably pure recovered silica provides a commercial byproduct from this environmentally friendly power source.

Brookhaven chemist Mow Lin, who invented the new silica recovery process with retired Brookhaven scientist Eugene Premuzic and Caithness researchers, said, "Our new process allows geothermal power to be more cost-competitive through lowered production costs, and it may lead to new industries - and therefore, employment - in the states rich in goethermal resources."

Silica is used widely as a drying agent for products such as salt; a polishing agent for commodities such as toothpaste; as a filler, extender or reinforcer for plastics, paper, paint and rubber; and as a catalyst for refining oil. It also has applications in fiber optics and in nanoscience.

Previous research at Brookhaven focused on silica recovered from high-salinity goethermal brines that contain many impurities. These impurities may include iron, as well as other metal salts such as zinc and manganese, and have to be removed at high cost in order to produce marketable silica. In contrast, the new Brookhaven/Caithness technology recovers silica from low-salinity brines that contain very few impurities.

Since the recovered silica using the new process is 99.9 percent pure - much purer than most silica on the market today - new uses may be found for it, including chemical production. Also, the availability of very pure and relatively inexpensive silica may lead to refinement of existing products, particularly in nanoscale materials, like chips for sub-micron electronic circuits.

The conventional process for producing silica involves fusion of silica sand with alkali to make silicate. The alkali silicate is then neutralized with acid yielding precipitated silica. The product is costly when compared with the Brookhaven/Caithness process, which is based on precipitation. A chemical reactor especially developed for the process precipitates the silica from geothermal brine under specific processing conditions.


Brookhaven and Caithness are now taking steps to commercialize the process. This work was funded by the U.S. Department of Energy's Energy Efficiency and Renewable Energy Program.

The U.S. Department of Energy's Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies. Brookhaven also builds and operates major facilities available to university, industrial, and government scientists. The Laboratory is managed by Brookhaven Science Associates, a limited liability company founded by Stony Brook University and Battelle, a nonprofit applied science and technology organization.

Note to local editors: Mow Lin lives in Rocky Point, NY, and Eugene Premuzic lives in East Moriches, NY.

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