Saturday, November 17, 2012

How can U.S. achieve its renewable fuel targets?

Ethanol leads the way in U.S. biofuel production. In the last 20 years there has been a growing demand for more renewable fuels in United States, with corn-derived ethanol, a biofuel produced through the fermentation of sugar in corn kernels, currently leading the US biofuel industry forward.

Under the U.S. Renewable Fuel Standard (RFS) 36 billion gallons of biofuel are supposed to go into U.S. vehicles by the year 2022. In order to achieve this goal the main focus will no doubt be on corn-based ethanol, or to be more precise by adding corn-based ethanol to gasoline.

Is this goal reachable with ethanol alone? According to the US researchers ethanol alone is not enough to achieve the RFS targets because currently available technologies are able to use only limited amounts of ethanol.

In 2011, Wallace Tyner, an agricultural economist from Purdue University, said that U.S. is already producing more corn-based ethanol than it can use, concluding that relying solely on ethanol will not be enough to meet the US renewable fuel targets.

Many cars on U.S. roads are not compatible with E85 blend.

Tyner believes that U.S. does not only have to improve current technologies in order to create biofuels that have more similar properties to gasoline than ethanol but also needs to change its vehicle fleet.
Today, the most gas stations in America pump gasoline that has 10 percent ethanol and 90 percent gasoline, a blend known as E10. Higher blends are still not widespread because there is still large number of older cars that have incompatible engine parts.

Such a countrywide usage of E10 means that U.S. is already producing more ethanol than it needs to create enough E10 fuel, and this is the main reason why U.S. cannot only rely on ethanol to meet its renewable fuel targets.

The higher blends of ethanol such as for instance E85 blend, which consists of 85 % ethanol, are available but there is not enough cars on U.S. roads to support use of higher blends (there are only around 7 million cars on U.S. roads that could support such high blend, and in order to meet RFS 2022 goal US would need to have at least 90 million E85 compatible cars on the road).

The U.S. therefore needs to focus on diversifying its biofuel production, especially focusing on more advanced biofuels (such as biofuels from cellulose and other plant waste products) and not rely solely on ethanol. These advanced biofuels would not only help meet RFS goals but they are better for environment compared to ethanol because they produce less greenhouse gas emissions than ethanol, and they also require less energy in production process.

However, these new biofuels need new technologies because current technologies are not enough to make them commercially feasible. New technologies require plenty of research and of course significant investment but this looks to be the only way for U.S. to meet the RFS goals for 2022.