Ethanol is a relatively low-cost alternative fuel that boasts less pollution and more availability compared to unblended gasoline, but there are a number of benefits and drawbacks to this newer form of fuel.
For environmental purposes, ethanol is less harmful than unblended gasoline. Carbon monoxide production from ethanol fuel is significantly lower than that of gasoline engines, and ethanol is easier to source since it comes from processed corn. This means it also helps farms and manufacturing economies.
The disadvantages of ethanol and other biofuels include the use of farmland for industrial corn and soy growth, rather than for food crops. Also, biofuels aren't meant for all vehicles, especially older vehicles. There is some resistance from the automotive industry when it comes to adding biofuels to the market. However, many automakers are adapting to low-emissions vehicle standards which require vehicles to use ethanol blends rather than unblended gasoline.
Ethanol Benefits for the Environment and Economy
Overall, ethanol is considered to be better for the environment than gasoline. Ethanol-fueled vehicles produce lower carbon dioxide emissions, and the same or lower levels of hydrocarbon and oxides of nitrogen emissions.
E85, a blend of 85 percent ethanol and 15 percent gasoline, also has fewer volatile components than gasoline, which means fewer gas emissions from evaporation. Adding ethanol to gasoline in lower percentages, such as 10 percent ethanol and 90 percent gasoline (E10), reduces carbon monoxide emissions from the gasoline and improves fuel octane.
Flexible fuel vehicles that can use E85 are widely available and come in many different styles from most major auto manufacturers. E85 is also widely available at a growing number of gas stations throughout the United States. Flexible fuel vehicles have the advantage of being able to use E85, gasoline, or a combination of the two, giving drivers the flexibility to choose the fuel that is most readily available and best suited to their needs.
Because ethanol is mostly a product of processed corn, ethanol production supports farmers and creates domestic jobs. And because ethanol is produced domestically, from domestically-grown crops, it reduces U.S. dependence on foreign oil and increases the nation's energy independence.
Being able to grow ethanol-producing crops reduces the pressure to drill in environmentally-sensitive places, such as the north slope of Alaska, the Arctic Ocean, and the Gulf of Mexico. It can replace the necessity for environmentally-sensitive shale oil, like that coming from the Bakken Shale, and reduces the need for the construction of new pipelines like the Dakota Access Pipeline.
The Drawbacks of Ethanol
Ethanol and other biofuels are often promoted as clean, low-cost alternatives to gasoline, but the production and use of ethanol are not all positive. The major debate about corn and soy-based biofuels is the amount of land it takes away from food production. Also, industrial corn and soy farming are harmful to the environment in a different way.
Growing corn for ethanol involves large amounts of synthetic fertilizer and herbicide. Corn production, in general, is a frequent source of nutrient and sediment pollution. Also, the typical practices of industrial corn farmers, versus commercial and local food farmers, are considered more environmentally hazardous in general.
The challenge of growing enough crops to meet the demands of ethanol and biodiesel production is significant and, some say, insurmountable. According to some authorities, producing enough biofuels to enable their widespread adoption could mean converting most of the world's remaining forests and open spaces to farmland - a sacrifice few people would be willing to make.
“Replacing only five percent of the nation's diesel consumption with biodiesel would require diverting approximately 60 percent of today's soy crops to biodiesel production,” says Matthew Brown, an energy consultant and former energy program director at the National Conference of State Legislatures.
In a 2005 study, Cornell University researcher David Pimental factored in the energy needed to grow crops and convert them to biofuels and concluded that producing ethanol from corn required 29 percent more energy than ethanol is capable of generating.
EarthTalk staff. "The Pros and Cons of Biofuels." James T. Ehler, February 2007.
Susan S. Lang. "Cornell ecologist's study finds that producing ethanol and biodiesel from corn and other crops is not worth the energy." Cornell Chronicle, July 5, 2005, Ithaca NY.