I-Corps: Biological solutions for recovery of rare earth elements

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is the development of a bacterial bioprocess to generate rare earth elements (REEs). Rare earth elements are critical metals used in technologies such as consumer electronics and electric vehicles, and demand for these metals continues to increase annually by 8-10%. More than 50 million tons of electronic waste (E-waste) are generated globally each year. Recycling REEs from E-waste would impact billions of people worldwide by reducing the waste footprint, groundwater and soil contamination, and electronics costs. The proposed technology has the potential to reduce the carbon footprint of rare earth oxide production by 25–70% compared to current hydrometallurgical processes, preventing environmental damage estimated at $14.8 billion. In addition, developing technologies for domestic REE reuse and recycling may provide a path towards independence from foreign importation and offers a unique opportunity to generate an REE remediation and recycling pipeline, removing heavy metal contaminants from low-grade waste streams (medical waste, wastewater, fly ash) and resupplying the REEs to electronics manufacturers. This I-Corps project is based on the development of a microbial platform for one-step bioleaching, separation, and bioaccumulation of rare earth elements (REEs) from waste sources. It is combined with a purification process to provide low-cost, sustainable, manufacturing-grade rare earth oxides (REOs). The proposed process uses microbes that produce rare earth binding ligands that are highly specific for REEs, removing the need for harsh acids, high temperatures and pressures, and solvent extraction steps involved in canonical hydrometallurgical and pyrometallurgical production schemes. This bacterial process is built on the discovery that specific bacteria are able to selectively solubilize, transport, and bioaccumulate REEs from complex sources. Using genetic and metabolic engineering, a bacterial platform has been developed that exhibits enhanced bioleaching and bioaccumulation of REEs with high specificity. The proposed technology currently has the capacity to recover REEs at the g/L scale from electronic waste. If successful, this could be used to produce REOs using waste feedstocks, reducing the environmental burden of production. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.