Isobutanol is a four-carbon alcohol traditionally produced via high-cost petrochemical routes. As a result, the market for isobutanol has historically been limited to markets such as solvents and other specialty chemicals. Gevo produces isobutanol through efficient fermentations.

Isobutanol offers a number of properties that are more attractive for a renewable gasoline blendstock than ethanol, including:

• Properties of butanol are closer to gasoline than properties of ethanol; e.g. heating value, blending vapor pressure, water tolerance, corrosivity and polarity.

• Blending ratio of butanol is higher than that of ethanol within the same oxygen limit, e.g. 3.6 wt-% oxygen is equivalent to 15-16 vol-% of butanol, but 10 vol-% of ethanol.

• Compatibility of isobutanol and n-butanol with conventional cars and infrastructure is better than that of ethanol. Butanol is not very aggressive towards materials and phase separation risk is low.

There are two Clean Air Act provisions that allow for blending of up to 12.5% biobutanol with gasoline. The fuel quality standard for Biobutanol—ASTM D7862—also allows for a biobutanol blend of up to 12.5% with gasoline.

(According to the US Department of Energy (DOE), major refiners currently cannot sell biobutanol blends for on-road use because it is not registered under 40 CFR (Code of Federal Regulations) Part 79 for companies with revenues exceeding $50 million, as required by the Clean Air Act.)

Gevo expects that the 12.5% blend of isobutanol and gasoline is attractive to customers who are looking for a higher-performance alternative to ethanol-blended gasoline.

For Gevo, the on-road gasoline market represents a much larger market opportunity for isobutanol than specialty segments. Selling into the on-road market also counterbalances the seasonal nature of some of the specialty markets like marinas.

Gevo’s planned core markets. The new move to on-road distribution fits with the gasoline blendstock area. Click to enlarge.

This expands on the previously publicized partnership between Gevo and Musket. In June, Gevo announced it had entered into an agreement with Musket to supply isobutanol for blending with gasoline. Musket is a national fuel distributor under the umbrella of the Love’s Family of Companies and specializes in commodity supply, trading and logistics across North America. Under the partnership, the initial target markets were Musket’s marine and off-road customers in Arizona, Nevada, and Utah.