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Energy Storage

ExxonMobil plans to use direct lithium extraction in Arkansas

The deep-pocketed firm has drilling expertise but needs technology for separating lithium from brine

by Matt Blois
November 16, 2023 | A version of this story appeared in Volume 101, Issue 38


A white warehouse containing equipment for extracting lithium from brine.
Credit: Matt Blois/C&EN
Standard Lithium extracts lithium from subterranean brine at a pilot-scale facility in Arkansas. Now the oil giant Exxon Mobil hopes to do the same.

The oil behemoth ExxonMobil has started a project to exploit subterranean brines in southwest Arkansas for lithium, a metal used to make batteries for vehicles that don’t require Exxon’s primary product: fossil fuels. The deep-pocketed firm has the expertise required to drill wells but needs technology to extract lithium from brine and turn it into a material that battery companies can use.

Exxon’s plan is to pump lithium-rich brines from far underground and chemically remove the metal using direct lithium extraction (DLE), a family of separation technologies that hasn’t been deployed at commercial scale. The company hopes to start production in 2027 and says it intends to eventually become a leading producer of the mineral.

“We see an opportunity to really leverage the things that we’re pretty good at,” Exxon CEO Darren Woods said on an Oct. 27 conference call, referring to the company’s lithium plans. “It looks fairly promising at this stage. And I would just say the aperture is wide open.”

Nearly all of the world’s lithium comes from hard rock mines or large pond systems that concentrate lithium from brine using evaporation. But several companies are already trying to use DLE to extract lithium from Arkansas brines.

Standard Lithium has a demonstration plant in El Dorado, Arkansas, and hopes to start up a commercial-scale facility by 2026. The established lithium chemical firm Albemarle produces bromine from brine in Magnolia, Arkansas, and has been piloting DLE technologies there for years. But the company is focused on expanding lithium production through more established routes, such as hard-rock mining. Albemarle recently offered $4.2 billion to buy a hard rock lithium mine in Australia, though the deal fell through. And it also plans to open a hard rock mine in North Carolina.

Other oil firms have also made investments in the lithium industry, with much of the focus on DLE. Occidental Petroleum formed a joint venture with All-American Lithium to extract lithium from geothermal brines in California’s Salton Sea using DLE. Schlumberger is developing a DLE process to produce lithium from brines in Nevada.

Exxon produced more than 1.3 million barrels of crude oil per day in 2022, so it has the expertise needed to pump brine out and reinject it after processing, according to Andy Leyland, managing director of the lithium consulting firm SC Insights. But a DLE technology that can economically pull lithium out of the brine will be key to the company’s success, and it’s not yet clear where that will come from.

“Exxon have the first in spades, the second they clearly think they can commercialize,” Leyland says. “Exxon will have tested this, but like everyone else, won’t know how well it works at a commercial scale yet.”

In January, Exxon acquired a firm called Saltwerx that specializes in repurposing old oil wells to extract brine, according to the business intelligence firm Pitchbook. In September, regulators in Arkansas granted Saltwerx and Tetra Technologies permission to extract lithium. Saltwerx and Tetra are now negotiating a joint venture and will work together on DLE. Exxon did not respond to questions about the specific DLE technology it plans to use.

While several companies are getting closer to achieving large-scale lithium production using DLE, Leyland says it’s still risky. Exxon will also have to prove to battery manufacturers that it can produce a material that is consistent enough to meet their specifications.

Still, Leyland says oil and gas companies have strengths that they can leverage in the energy storage market. “I don’t think it’ll be the last move that Exxon makes in the battery space,” he says.


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