Materials for Energy, Efficiency and Sustainability: TechConnect Briefs 2016Materials for Energy, Efficiency and Sustainability TechConnect Briefs 2016

Biofuels and Bioproducts Chapter 6

The Electrobiome® Platform: Synthesis of ElectroFuels and Chemicals from CO2

H.D. May, E.V. LaBelle
Synbiohm LLC and Medical University of South Carolina, United States

pp. 175 - 178

Keywords: electrofuels, sustainable energy, CO2 utilization, electrobiome, hydrogen, acetic acid, ethanol, butanol, caproate, chain elongation, long-chain hydrocarbons

Technology: Dr. May and colleagues have discovered and developed the Electrobiome® which converts CO2, water, and electricity into hydrogen (H2), formic acid, and acetic acid while serving as a biocathode in an electrochemical cell. Synbiohm LLC and MUSC researchers are now working to expand the capability of this microbial platform to increase product yield, rates, and titers and to produce ethanol, butanol, caproic acid, and long-chain hydrocarbons. The Electrobiome has been continually operating for >3 years and the electrical input can be intermittent, allowing it to operate with stranded, interruptible, or curtailed power. Therefore, the Electrobiome could be used to convert and store electricity into higher value fuels or chemicals. Thus far, when directed to H2 the Electrobiome has generated up to 38 LH2/Lcatholyte/day or >1kg of H2 per m3 of reactor volume (1 kg H2 ≈ 1 gallon gasoline equivalent). Alternatively, when directed to acetic acid it has produced up to 3.1 kgacetate/m3catholyte/day. These rates have been achieved with ~$4 of electricity at $0.05 per kWh. Off-peak, interruptible, or curtailed power may be purchased at half of that rate, or less, thereby placing the electricity cost for producing 1 kg of H2 near the retail price of a gallon of gasoline. The goals of the present research are to produce higher value fuels or chemicals, e.g. butanol, a drop-in liquid fuel, and caproate, a higher value chemical that may serve as a diesel precursor, for