Magnesium could be extracted from the ocean in a process being developed at Pacific Northwest National Laboratory to provide lightweight metal to reduce fuel use in cars and planes.
The Department of Energy national laboratory in Richland is leading the three-year project with a $2.43 million grant from DOE's Advanced Research Projects Agency -- Energy, or ARPA-E.
Researchers plan to develop a new way to remove naturally occurring magnesium from sea water. The research could make fuel-efficient transportation more affordable and expand the American magnesium market.
"Demand for lightweight metals such as magnesium is growing, but it's expensive and energy-intensive to produce them," said the project's lead researcher, Pete McGrail, a PNNL laboratory fellow. "We expect our method will be 50 percent more energy efficient than the United States' current magnesium production process. This will also decrease carbon emissions and the cost."
Among the lightest of metals, magnesium is used in alloys that decrease weight and increase strength of key parts used in vehicles, airplanes, power generation equipment, industrial processes and buildings.
But magnesium is about seven times more expensive to produce than the steel traditionally used. Producing lightweight metals also requires a lot of energy, and that creates carbon emissions.
The United States is home to just one bulk magnesium plant in Utah, where brine from the Great Salt Lake region is put through a chemical reaction called electrolysis to extract the metal from a molten salt. About a third of the nation's magnesium is imported, and China is the world's largest producer. China uses another method called the Pidgeon process, which requires significantly more energy and creates substantially more carbon emissions than the method used in Utah.
Reinventing the magnesium production process to make it more affordable could decrease U.S. reliance on foreign-made materials, McGrail said.
PNNL is developing a titanium-based catalyst that regenerates an important chemical used in the magnesium extraction process. The process requires temperatures of no more than 575 degrees, which is much lower than the 1,650 degrees required by the current U.S. process.
PNNL will draw on its expertise in catalyst development, molecular simulation, powder metallurgy and metal-organic chemistry for the project. Detailed computer modeling and follow-up lab tests will be used to pinpoint the catalyst's specific chemical makeup.
The project team plans to develop a prototype system. Commercial-scale magnesium production with the new process is expected to halve the current U.S. production cost, according to PNNL. It should cost less than $1.50 and require only 25 kilowatt-hours of energy per kilogram.
PNNL is working with Global Seawater Extraction Technologies and Utah magnesium plant owner U.S. Magnesium. The new production method will use a crystallization process developed by Global Seawater Extraction Technologies and tap electrolysis and practical magnesium production experience from U.S. Magnesium.
The ARPA-E grant will be matched with $210,000 from Global Seawater Extraction Technologies and $60,000 from U.S. Magnesium.
In addition to McGrail, researchers Satish Nune, Phillip Koech, Vassiliki-Alexandra Glezakou, Radha Motkuri, Carlos Fernandez, Sudhir Ramprasad and Leo Fifield are working on the project.