EAGER: A Novel Multi-Tray Dry Biofilm Reactor for Methane Capture from Air

Recent studies have shown that methane (CH4) contributes approximately 0.5ºC of the observed 1.1ºC present-day warming relative to the Earth’s pre-industrial global surface temperature. As a result, it is now broadly accepted that abatement of CH4 emissions should be a critical focus for slowing global warming by 2050. It is predicted that removal of 300 million tons of atmospheric CH4 can reduce global warming by 0.1-0.2ºC by 2050, a magnitude that would have a positive impact on the planet’s climate. However, a decrease of this magnitude will require removal of CH4 directly from the atmosphere, a process for which no scalable technology exists. To fill this gap, the research team proposes to develop and validate a novel, proof-of-concept multi-tray biofilm reactor that can directly capture CH4 from the air in areas with local CH4 concentrations of 500-5000 ppm, such as landfills, manure lagoons, or wastewater treatment plants, and that will convert the CH4 to a valuable product: protein for animal feed. Although multiple technologies are under development for converting point-source CH4 (e.g., natural gas or biogas with 10~40% CH4), no economically feasible technology exists to capture CH4 in the 500-5000 ppm range. This research program will focus on developing a multi-tray high-reaction-surface “dry” biofilm reactor that offers a novel solution to addressing the fundamental challenges inherent to aqueous bioconversion of gas substrates that have low solubility in water. This research program will advance understanding of the capability of biofilm-based conversion of atmospheric CH4, a greenhouse gas (GHG) that currently contributes approximately 0.5ºC of the present-day warming relative to the pre-industrial global surface temperature. This research will validate, for the first time, the potential of producing single-cell proteins (SCP) using CH4 captured directly from the air and will provide a quantitative estimate of the economic feasibility and environmental impact of the proposed technology. If successful, the proposed biofilm reactor will be the first such design capable of sustainably capturing CH4 from the air with local CH4 concentration ranging from 500 to 5000 ppm and achieving longer term CH4 sequestration as SCP by incorporating it in animal or aquaculture feed, further reducing the emission of GHG. The modular design of this biofilm reactor will facilitate scale-up for sites of varying GHG production rates. If successful, the proposed technology has the potential to contribute to slow global warming, assisting in achieving the ambitious, but necessarily, goal of 300 million tons of atmospheric CH4 removal by 2050, averting 0.1-0.2°C of global warming. Additionally, this research will open doors to the biofilm-based conversion of other gas substrates (e.g., shale gas, syngas, and biogas), by circumventing the challenges associated with the bioconversion of gas substrates with low aqueous solubilities. 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.