Integrated System for Electromicrobial Production of Butanol from Air-Captured CO2

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OPEN 2021
Berkeley, California
Project Term:
04/22/2022 - 04/29/2024

Technology Description:

The University of California, Berkeley (UC Berkeley) team will jointly develop an integrated process to produce butanol directly from air-captured carbon dioxide (CO2). Butanol has a higher energy density than ethanol and is a precursor to jet fuel. UC Berkeley’s system takes three main inputs: ambient air, water, and a sustainable energy source, and produces butanol. The steps to produce butanol are : (1) capturing CO2 directly from the air by a solid adsorbent, (2) using a chemoautotrophic microorganism to biologically fix the captured CO2 into acetate, and (3) using acetate as a feedstock for the heterotrophic production of butanol via metabolically engineered bacteria. (Chemoautotrophs are organisms that consume CO2 and a chemical source of energy; heterotrophs are organisms that cannot utilize CO2 and instead metabolize organic compounds for nutrition.) Preliminary models indicate that butanol production from the proposed process will be more sustainable than traditional butanol fermentation.

Potential Impact:

UC Berkeley’s proposed process will result in a ground-breaking carbon capture system coupled with electromicrobial production of a renewable biofuel and precursor to jet fuel.


The process will enable a technical roadmap to sustainable biofuels and value-added chemical products.


The proposed process is projected to have substantially lower GHG emissions compared with traditional corn-derived biofuels.


Preliminary analysis suggests that the proposed process can produce butanol at $6.60 per gallon of gasoline equivalent by 2030, with further room for cost reductions. This cost is within 50% of the current cost of corn-based biofuel ($4.50/gal gasoline equivalent including U.S. corn subsidies) with substantially less land use.


ARPA-E Program Director:
Dr. James Seaba
Project Contact:
Prof. Douglas Clark
Press and General Inquiries Email:
Project Contact Email:


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