How water innovation could be key to a sustainable economy

Workers in hard hats and protective gear crouch working around a drum of green liquid — The Princeton PureLi team works with partners in the salt flats of the Atacama desert in Chile to improve lithium production from brine. Photo courtesy of Z. Jason Ren

It did not take long for the business world to tune in after Z. Jason Ren and team published a 2023 paper on how to capture lithium, the essential element of batteries, from briny water with great efficiency.

Ren, a professor of civil and environmental engineering and the Andlinger Center for Energy and the Environment, leads a group that focuses on making more efficient use of water, particularly by recovering valuable resources and slashing greenhouse gas emissions from impaired water sources such as salty brine and wastewater.

When the group hit on a simple technology that would vastly lower the energy consumption and land use required for harvesting lithium, Ren’s postdoctoral researcher Sean Zheng left Princeton to cofound a company, PureLi, to bring the idea to market. The company soon won support from the Grantham Foundation and venture capital firm SOSV as part of the firm’s HAX startup accelerator in Newark. It is now setting up two pilot projects to extract lithium in Chile. Their system can shrink by 90% an extraction process that typically requires square miles of evaporation ponds.

For Ren, the lithium project is one example of the urgency he feels around using fundamental science to reveal where inefficient management of waste streams is harming the environment and developing solutions that move toward a “circular economy.”

“At its root, my lab asks, ‘How do we maintain a sustainable operation of our society?’,” Ren said.

In a different project, Ren is collaborating with New Jersey Resources, a company that provides natural gas utility and clean energy services, to develop ways to extract hydrogen, a clean-burning fuel, and oxygen from municipal wastewater effluent. New Jersey Resources is working on novel approaches to clean hydrogen development to decarbonize its energy sources. The same process would allow the water resource recovery utility to use the oxygen to greatly lower the energy needed to process municipal wastewater.

“At wastewater treatment plants, their waste is our gain, and our waste — oxygen — is their gain,” said Chris Chen, business development manager for New Jersey Resources. “This is the type of circular ecosystem we are looking for, and that’s why this is a great project to do with Jason.”