Produced water that returns to the surface as wastewater after oil and gas hydraulic fracturing processes in parts of Appalachia can be a source of lithium, a valuable chemical element used in consumer products, according to an important new report from NETL.

Lithium is used in rechargeable batteries for products from mobile phones, laptop computers, and digital cameras to electric vehicles, heart pacemakers, toys and clocks.

Justin Mackey, the lead investigator on the project, said “The drilling boom in Appalachia created large volumes of produced water that is considered a waste. We found that this fluid is significantly enriched with lithium compared to produced water from other shale formations.”

Marcellus Shale contains interlayered beds of volcanic ash where lithium has been partitioned from the volcanic ash into fluids. The NETL research shows that potential lithium yields and recovery efficiencies are different between the northeast and southwest regions of Pennsylvania.

The NETL research suggests that Marcellus Shale production wastewater from the two Pennsylvania regions could meet 38–40% of current domestic lithium consumption. The research shows that Marcellus Shale produced water has the capacity to provide significant lithium yields for the foreseeable future. Currently, domestic lithium consumption is estimated at 3,000 metric tons annually.

The NETL report, coauthored by Justin Mackey, Daniel J. Bain, Greg Lackey, James Gardiner, Djuna Gulliver and Barbara Kutchko, indicates that currently, 95% of the produced water being generated is reinjected during ongoing hydraulic fracturing operations.

“Typically, produced water is transported via a network of pipelines to a central facility where it is minimally treated to remove solids prior to reinjection at other well sites,” Kutchko of NETL’s biochemistry and water team said. “Ultimately, our results show mass lithium yields from Marcellus produced water are substantial and could offset associated infrastructure and disposal costs while providing a significant domestic source of lithium.”

According to U.S. Geological Survey estimates, there is roughly 96 trillion cubic feet of undiscovered gas in the Marcellus. The NETL report suggests that the production lifetime of the formation could exceed several decades. North-central Pennsylvania is underdeveloped and has some of the of the highest lithium concentrations included in the analysis.

The NETL study used chemical and production compliance data reported to the Pennsylvania Department of Environmental Protection to predict lithium mass yields from the Pennsylvania sites. In total, 595 reports were considered from 515 wells.

The work was performed in support of the U.S. Department of Energy’s Fossil Energy and Carbon Management and the datasets generated in the study are available on NETL’s Energy Data eXchange (EDX) here.

NETL is a U.S. Department of Energy national laboratory that drives innovation and delivers technological solutions for an environmentally sustainable and prosperous energy future. By using its world-class talent and research facilities, NETL is ensuring affordable, abundant and reliable energy that drives a robust economy and national security, while developing technologies to manage carbon across the full life cycle, enabling environmental sustainability for all Americans.