The Reemergence of Biobased Isobutanol

By Kolby Hoagland | June 20, 2013

Gevo Inc. recently announced that it has resumed commercial production of biobased isobutanol in its Luvern, Minnesota plant. Once strictly an ethanol plant, Gevo purchased the Luvern plant in 2010 to produce isobutanol. Though the microbes are different, isobutanol is a product of fermentation like ethanol. The similar method to producing ethanol and isobutanol allows Gevo to use a significant portion of the existing infrastructure at the plant. Genetically modified cyanobacteria and ecoli have been developed to synthesize isobutanal at a faster rate than is possible with naturally occurring microbes. As of June 18, Gevo has restarted the once strictly ethanol facility in Luverne to produce biobased isobutanol at commercial scale.

Isobutanol has some distinct advantages to ethanol as a bio-based commodity:

- Isobutanol the primary feedstock for numerous chemical products

- The energy density of isobutanol is nearly identical to gasoline

- Isobutanol is a non-polar, hydrophobic (repels water) molecule, whereas ethanol is a polar, hydrophilic (attracts water) molecule

- Isobutanol will not suffer from phase separation when mixed with gasoline for an extented period of time

Isobutanol is a true drop-in fuel for gasoline, and with the market potential as chemical industry feedstock, Gevo is leading the way in the production of biobased isobutanol. Below are the molecular structures of isobutanol and ethanol. Both molecules comprise one oxygen atom, but isobutanol has two more carbon and four more hydrogen atoms. Though distinctly different molecules requiring different microbes for fermentation, current ethanol plants may to Gevo on how to diversify their product streams and reinforce the economic security of the plant. Future DataPoints will follow the Gevo story.


Isobutanol vs. Ethanol