Here are the basics of the corn-based fuel, ethanol.
What is ethanol?
Biofuels are transportation fuels made from plants. Ethanol is a type of biofuel made from corn.
Is ethanol always made from corn?
In the United States, a majority of ethanol is made from corn. But ethanol can also be made from soybeans, sugarcane, wheat, barley, sorghum, switchgrass, or miscanthus.
Why is most ethanol made of corn?
Corn is high in starch, meaning it contains lots of energy. By distilling this energy during a fermentation process, corn can be turned into fuel.
Its starchiness is just one reason corn-based ethanol dominates the market. The other reason is political.
Federal policies require refiners to blend ethanol into gasoline. A law passed in 2007 established the Renewable Fuel Standard (RFS), which requires yearly increases in the amount of ethanol be blended into gasoline. Farmers have responded by growing more corn. Thus, corn has remained an abundant commodity in the United States and continues to be the main source of biofuels
The RFS aims to reach 36 billion gallons of ethanol by 2022, but these targets are rarely met. Only 12.6 billion gallons of ethanol were consumed in 2020, around 10% of the total gasoline consumed in the U.S.
Where can I purchase fuel with ethanol?
Likely the nearest gas station! Whether you know it or not, your car likely has some ethanol in the tank right now. On its own, ethanol is not strong enough to power most cars, so it’s typically blended with gasoline — to make E10, E15, or other types of gas.
Ok….But what do E10, E15, or E85 mean?
E10 and E15 stand for the percentage of ethanol blended into gas. E10 means the mixture is 10% ethanol and 90% gasoline; E15 is 15% ethanol and 85% gasoline. Most cars on the road today use E10 or E15.
There are also blends like E85, which is 51%-83% ethanol. A flex-fuel vehicle is designed to burn these ethanol-rich fuels. By checking the color of your gas cap, you can quickly determine if you have a flex-fuel vehicle. A yellow cap means you can put E85 in your car. E85 is typically the cheapest fuel at the gas station. But it’s important to know that your car likely won’t get as many miles per gallon with higher blends of ethanol.
Fuel blend options at a gas station. Image Courtesy:https://upload.wikimedia.org/wikipedia/commons/thumb/3/3c/Blender_fuels_close-up_view.JPG/640px-Blender_fuels_close-up_view.JPG
Check out these resources to learn more about how to identify a flex-fuel vehicle: https://www.fueleconomy.gov/feg/flextech.shtml
I’ve heard that ethanol is just as bad for the environment as gasoline, is that true?
Yes and no… There is actually quite a bit of controversy about how sustainable ethanol is.
Basically, there are two sides: biofuel advocates (farmers, ethanol plants, agriculture-focused trade associations) and biofuel opponents (environmentalists, renewable energy experts, and oil refiners).
Biofuel advocates argue that ethanol is a renewable energy source that reduces our dependence on fossil fuels and lowers carbon emissions. They often claim that ethanol is a home-grown (which it is!), clean energy solution. A 2021 study found that ethanol is half as carbon-intensive as gasoline. A 50% reduction is certainly an improvement, but it doesn’t mean biofuels are carbon neutral.
Biofuel opponents have argued for years that ethanol is not a viable fuel. Ethanol is not carbon neutral and turning corn into fuel requires energy (the distilling process mentioned above), which produces a lot of CO2. A recent report calculated that the amount of corn planted today does not offset these emissions.
We also know that ethanol puts other natural resources at risk. Corn requires significant amounts of nitrogen fertilizer to grow. Lots of fertilizer means lots of potential pollution, especially for lakes, rivers, and oceans.
So… it seems like ethanol might not make sense environmentally. Why do we keep it around?
The short answer: politics keep ethanol in our gasoline.
What’s arguably most important to understand is that ethanol holds a lot of social and economic promise for rural communities in the Corn Belt. Ethanol sales support rural communities, farmers, and sustain local economies. Many politicians continue to be staunch supporters of ethanol since any proposed changes in ethanol regulations are seen as threats to Midwestern farmers.
***
The above only introduces the complexity that accompanies ethanol in the United States. While the science might clearly say “hey, this isn’t a fuel we should be depending on anymore,” that is only one layer of the debate. The social and economical angles of ethanol – only touched on in this piece – mean there are significant consequences for farmers and their communities if we were to take the fuel off the market today.