The Environmental Protection Agency is currently seeking public comment on the use of
isobutanol as a fuel additive. Butamax Advanced Biofuels has submitted an application to the
EPA seeking its registration as a fuel additive of up to 16% volume, pursuant to the regulation
titled “Registration of Fuels and Fuel Additives.” The Clean Air Act requires fuel additives to be
registered with the EPA once the manufacturer has met the registration requirements – the
likelihood of the EPA approving the additive is what has prompted the Agency to make the
public aware of the potential registration.
Butanol is an alcohol, as is the nearly ubiquitous ethanol, and is garnering attention as an
attractive alternative. Ethanol is an alcohol with a relatively short carbon chain, allowing it to
blend with water as well as with fuel. Isobutanol, an isomer of butanol, has a longer carbon
chain, thus making it more at home in a solution with fuel than one with water. This property
makes it less likely to tolerate the intrusion of water into a fuel supply. More simply put, an
ethanol-blended fuel will absorb some water while an isobutanol-blended fuel will not.
The fact that the proposed additive does not absorb water would prove beneficial in humid
environments such as marinas; and to this point he National Marine Manufacturers Association
has endorsed gasoline containing isobutanol as being superior to fuel containing ethanol.
Further, Gulf Oil uses the additive in its racing fuels, maintaining that isobutanol-blended fuel is
excellent for both high-performance engines as well as everyday motors.
Moreover, isobutanol can also help the industry meet the Renewable Fuel Standard, as it fulfills
the same requirement as ethanol. A promising biofuel, isobutanol can be produced from non-
food sources, such as grass and agricultural waste, meaning it won’t compete with any food
market the way that ethanol has been known to do.
Isobutanol is also approved to travel in the same pipelines as traditional ethanol-blended
gasoline and is compatible with all vehicle engines, from motorcycles to boats. While its use
has been fairly limited—with primarily successes in Texas alone—the potential EPA designation
as an approved fuel additive would open up the market to large scale implementation.
Public comments will be accepted for the rest of this month by the EPA, at which point the
Agency will likely approve the use of isobutanol as a fuel additive. And, yes, we are eager to
hear how this turns out. At Clean Fuels National, we pride ourselves on staying up to date on
the ever-changing landscape of fuel regulation.
Is isobutanol the biofuel of the future? How will its cost stack up compared to traditional
ethanol-blended gasoline? What kind of unique challenges will it pose to fuel retailers? Check
back on our blog as we continue to look into and remain apprised of this new development.
More to come for sure!