Emerging from the forefront of environmental engineering research at Princeton University, a pioneering startup is redefining how critical minerals essential to clean energy and agriculture are extracted from brine. Princeton Critical Minerals (PCM), formerly known as PureLi, has developed an innovative solar evaporation technology that promises to significantly enhance the efficiency of lithium, nitrate, and potash production, all while reducing environmental impact. This breakthrough has the potential to transform a mineral extraction industry that has remained largely unchanged for decades, meeting the pressing global demand for sustainable resources.
At the core of PCM’s technology is a deceptively simple yet highly effective device: a black disc engineered with a specialized anti-fouling coating. These discs float on the surface of traditional open evaporation ponds—vast shallow basins containing mineral-rich brine—and absorb sunlight much more efficiently than the pond surfaces themselves. Acting like miniature solar collectors, the discs convert incoming solar radiation into thermal energy, substantially accelerating the evaporation process and thereby increasing the rate at which valuable minerals crystallize and can be harvested.
While conventional evaporation ponds disperse solar energy diffusely across large surface areas with less than 50% efficiency, PCM’s discs have demonstrated over 96% efficiency in converting sunlight into heat in real-world applications. This near-total absorption of solar energy effectively supplements the sun, turning these ponds into highly productive and compact evaporation systems. The concept has been vividly described by Princeton’s civil and environmental engineering professor Z. Jason Ren as “adding a second sun” to mineral extraction ponds, highlighting the stark contrast in energy conversion performance.
Field tests carried out in northern Chile—a global hotbed for lithium and nitrate mining—illustrate the transformative impact of this technology. In collaboration with Sociedad Química y Minera de Chile (SQM), one of the world’s leading chemical companies specializing in mining and agriculture, PCM deployed their floating discs in operational evaporation ponds. Results showed evaporation rates increased by an impressive 40 to 122 percent compared to traditional open ponds, variations depending on the specific brine composition. This drastic improvement not only boosts mineral yield but also shortens production cycles, directly addressing supply chain bottlenecks impacting clean energy technologies like electric vehicle batteries.
The implications of PCM’s technology extend beyond just improving output; by elevating the effectiveness of existing ponds, this innovation could curb the sprawling expansion of new evaporation sites. Conventional lithium extraction operations often require vast land areas—stretching across hundreds of square miles—to meet demand, a footprint that poses significant environmental challenges including habitat disruption and water resource depletion. PCM aims to substantially reduce this spatial footprint. More efficient ponds could mean fewer sites with smaller environmental impact, allowing mineral production to scale sustainably alongside global efforts to combat climate change.
PCM’s story is deeply intertwined with Princeton’s rich innovation ecosystem. The company originated in the academic collaboration between Professor Ren and Sean Zheng, who joined Ren’s lab as a Distinguished Postdoctoral Fellow at the Andlinger Center for Energy and the Environment. Their initial investigations stemmed from fundamental research into brine evaporation enhancement, which culminated in a scientific paper exploring the thermodynamics and interfacial processes governing solar evaporation. Recognizing the real-world potential, they leveraged university-supported entrepreneurship programs to translate laboratory knowledge into commercial technology.
Participation in initiatives such as the National Science Foundation’s I-Corps and Princeton’s IP Accelerator program provided crucial market insights and sharpened PCM’s business strategy by aligning scientific innovation with industry needs. These programs helped the founders discern that some technical phenomena that intrigued researchers held less significance for commercial viability, guiding them toward focusing on pragmatic operational improvements. Additionally, the START Innovators program fostered the transition from academic experimentation to entrepreneurship, equipping the team with essential skills in business planning and venture creation while nurturing continued technological development.
Support from Princeton’s Keller Center for Innovation in Engineering Education further accelerated PCM’s journey. The Design for Impact program, which blends financial support with expert mentorship, prepared the founders to hone their pitch and navigate the complexities of early-stage commercialization. This comprehensive support network exemplifies the multifaceted approach required to bridge the gap between academic breakthroughs and industry-scale deployment. According to Craig Arnold, Princeton’s Vice Dean for Innovation, PCM exemplifies how leveraging interdisciplinary university resources catalyzes translational research that can profoundly impact global challenges.
PCM’s rapid progress underscores the synergy between rigorous research and entrepreneurial drive. From testing small-scale prototypes in makeshift setups such as kiddie pools to deploying fully operational products in South American mineral facilities, their trajectory reflects a model of agile development anchored in real-world validation. This approach not only enhances product performance but also uncovers new research avenues. For instance, field data revealed that the solar-absorbing discs maintained higher surface temperatures relative to open ponds, with less heat transmitted to the pond bottom—a thermal stratification effect influencing mineral solubility and crystallization dynamics. Such insights fuel ongoing investigations into brine chemistry optimization at Princeton.
The partnership with SQM and other industry players is instrumental in advancing both scientific understanding and commercial deployment. Collaborative pilot projects substantiate not only the feasibility of the technology but also its adaptability across various brine compositions and extraction contexts. This iterative feedback loop between laboratory research and field application exemplifies a convergence of innovation and practicality critical for sustainable resource extraction, setting a precedent for future technologies to follow.
Beyond its immediate commercial promise, PCM’s innovation intends to inspire broader shifts within the scientific community. Professor Ren advocates that academic researchers view their work through the lens of societal impact, extending beyond publications to tangible solutions addressing pressing resource and environmental challenges. The success of PCM highlights the tangible benefits universities can offer by fostering ecosystems that support researchers in taking bold steps towards entrepreneurship without sacrificing academic rigor.
In an era where the demand for lithium and other critical minerals underpins the global transition to cleaner energy futures, technologies like PCM’s represent vital tools in minimizing environmental harm while maximizing resource efficiency. By doubling the efficiency of solar evaporation systems through advanced materials and clever design, PCM is poised to help build a more sustainable and resilient supply chain for the technologies driving the 21st-century energy transition.
As PCM moves toward full commercialization, the future holds promising vistas not only for mineral extraction but also for expanded scientific inquiry and sustainable engineering. Its story exemplifies how strategic university-industry partnerships, coupled with innovative technology and entrepreneurial zeal, can accelerate solutions to some of the most challenging problems facing humanity today.
Subject of Research: Not applicable
Article Title: Interfacial solar evaporation for sustainable brine mining
News Publication Date: 10-Feb-2025
Web References:
References:
- Ren, Z. J., Zheng, S., Khandelwal, A., Oelckers, B. "Interfacial solar evaporation for sustainable brine mining," Nature Water, 2025. DOI: 10.1038/s44221-025-00394-y
Image Credits: Bumper DeJesus, Andlinger Center for Energy and the Environment
Keywords: Solar evaporation, Lithium extraction, Critical minerals, Brine mining, Renewable energy, Evaporation ponds, Sustainable mining, Princeton University, Innovation ecosystem, Clean technology, Mineral production, Environmental engineering
