ARPA-E Archived Funding Opportunities

DE-FOA-0002751: Request for Information (RFI) on Phytomining for carbon-negative critical mineral supply chains


The purpose of this RFI is to solicit input for a potential future ARPA-E research program focused on technologies related to harvesting high value metals essential for the clean energy transition from terrestrial environments using metal hyperaccumulators (HAs). The goal is to establish economic, sustainable, and low carbon-footprint domestic supply chains of high value metals to promote an accelerated clean energy transition without supply chain constraints. ARPA-E is seeking information at this time regarding transformative and implementable technologies that could:

(a) Identify or develop hyperaccumulators suitable for economically viable phytomining in the United States. Examples include agronomic techniques to domesticate hyperaccumulating species, yield higher biomass, and to control the seed dispersal; systems biology approaches to gain desired phenotypes such as high rates of growth, fast metal uptake, and accumulation of optimal metal compounds in parts of the plant that are optimal for extraction with low carbon-footprint approaches. ARPA-E's interest includes perennial species with high biomass and high metal uptake, including tree species, and any hyperaccumulators that could be grown on high-metal, nonarable lands in the US such as ultramafic serpentine soil and mine tailings.

(b) Increase total metal uptake in hyperaccumulators that can be grown at large commercial scales in the United States. Examples include microbiome engineering to dissolve metals and engineering hyperaccumulators to grow deeper roots to expand the pool of metals available without strip mining. System-level approaches are encouraged to address the questions in this RFI. For example, employing integrated rhizosphere engineering, metal transport, and accumulation to desired locations in the plants such as saps, accumulation of metals in desired chemical forms, and monitoring/analysis tools.

(c) Extract metal from hyperaccumulators using processes that produce the lowest possible carbon emissions, ideally even carbon-negative. Examples include pre-treatment of biomass before or after drying to increase the yield, new metallurgical routes to extract metals with high yields and low impurities, and novel approaches to extract metals in desired chemical forms. ARPA-E is seeking information regarding extraction strategies without emitting carbon accumulated in the biomass back into the atmosphere. System-level approaches are encouraged to address the questions in this RFI. For example, employing integrated treatment of biomass to utilize accumulated carbon while extracting metals, co-processing of more than one type of biomass, integration with existing biomass processing routes, and recycling and recovery towards circular processes and economy.

(d) Produce high-value, high-purity chemical forms of metals directly from phytomining, which can enter the value chain of battery manufacturing and other clean-energy technologies without further processing. ARPA-E is seeking information for shortening the routes to clean energy-relevant mineral forms that can be used with minimal additional cost (CAPEX, energy, processing).

Note that some approaches may fit several of the technology categories described above. For instance, systems biology optimization of hyperaccumulators could be used to develop hyperaccumulators that are suitable for the climate and soil in the United States, while also increasing biomass, increasing metal uptake, and yielding the desired physical or chemical form of the metals of interest. Using nickel as an example target metal, ARPA-E is seeking information for new approaches that could reach at least 500 kg Ni/ha per year and >90% net greenhouse gas reduction compared to the state-of-the-art HPAL (high pressure acid leaching) process based on a lifecycle analysis.


No material submitted for review will be returned and there will be no formal or informal debriefing concerning the review of any submitted material. ARPA-E may contact respondents to request clarification or seek additional information relevant to this RFI. All responses provided will be considered, but ARPA-E will not respond to individual submissions or publish publicly a compendium of responses. Respondents shall not include any information in the response to this RFI that could be considered proprietary or confidential..

Responses to this RFI should be submitted in PDF format to the email address by 5:00 PM Eastern Time on May 26, 2022. Emails should conform to the following guidelines:

  • Please insert “Response to <insert RFI name> - <your organization name>” in the subject line of your email.
  • In the body of your email, include your name, title, organization, type of organization (e.g. university, non-governmental organization, small business, large business, federally funded research and development center (FFRDC), government-owned/government-operated (GOGO), etc.), email address, telephone number, and area of expertise.
  • Responses to this RFI are limited to no more than 12 pages in length (12-point font size).
  • Responders are strongly encouraged to include preliminary results, data, and figures that describe their potential processes.


  • RFI DE-FOA-0002751 on Phytomining for carbon-negative critical mineral supply chains (Last Updated: 4/11/2022 08:39 AM ET)

Submission Deadlines

  • Concept Paper Submission Deadline: TBD
  • Full Application Submission Deadline: TBD