Fact Checked

What is Ethanol Fuel?

John Sunshine
John Sunshine

Ethanol fuel is an alternative fuel to gasoline. Typically, it is made either from a grain such as corn or maize or from sugarcane. In the US, corn is primarily used to make ethanol, while in other generally warmer locations, sugarcane is the preferred source of biomaterial for making it. It is also possible to distill this fuel from petroleum oil, though the term is usually used to refer to bio-ethanol.

In some cases, this type of fuel can be used unmixed in an modified gasoline engine, but it is much more common to find an 85% gasoline and 15% ethanol fuel mixture. This mixture can be used directly in any gasoline engine. It burns cleaner in the engine, causing less pollution. If the ethanol is made from renewable bio-sources, then it also reduces the use of fossil fuels. Ethanol fuel does have a few disadvantages; it has a lower energy density than gasoline, so a tank will not go as far as a tank of gasoline, and it can be more difficult to start in very cold temperatures.

Sugar cane can be used to make ethanol.
Sugar cane can be used to make ethanol.

Ethanol fuel is also used as an oxygenate additive to gasoline. In the past, the chemical methyl tert-butyl ether (MTBE) was used for this purpose. This chemical has fallen out of favor, since MTBE is hazardous and very harmful to the environment. Ethanol can provide the same function without the negative effects to the environment. Oxygenating gasoline boosts the octane quality, enhances combustion and reduces carbon monoxide emissions. This practice sees more use during the winter months than it does during the summer.

In the US, bio-ethanol fuel is primarily made from corn or maize. This is largely due to the amount of corn that is grown in the US and the ease with which it is grown. Sugarcane is not as easily grown in the US.

Ethanol is made from corn in many places.
Ethanol is made from corn in many places.

Critics of this approach argue that the total energy input required to convert the corn into ethanol is almost equal to the energy in the fuel. However, the manufacture of this fuel is a relatively new business in North America, and improvements in the process are expected. The current production process is almost unchanged from the way corn whiskey was made during the pioneering days. The manufacture of ethanol fuel from corn is also changing from a limited scale production to large scale production by multinational corporations. These large corporations are researching ways to make the process more efficient.

A globe showing the Caribbean, where lots of sugarcane is produced and made into ethanol.
A globe showing the Caribbean, where lots of sugarcane is produced and made into ethanol.

In warmer climates, sugarcane is used. This process is much more favorable in terms of the energy recovered. In some cases, the leftover cane fiber material is also burned as a bio-fuel once the sugars have been removed from the cane. This increases the total amount of energy recovered from the process.

Brazil and some of the Caribbean islands are significant proponents of the sugarcane approach. Ethanol fuel is a significant contributor to the fuel requirements of these locations and is likely to continue to increase in importance. Brazil is perhaps the country that has most significantly adapted this technology, with 20% of the cars now using pure ethanol and at least 50% using a blend of gasoline and ethanol. The fuel is also posed to contribute a large share to the energy equation in the US in spite of concerns about the economics of the energy balance. Ethanol is a growing business, pun intended.

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Discussion Comments


I get 90 miles more on 13 gallons of gasoline than I get with gas and ethanol, how can we be using less petroleum?

Greed will kill us all.


Ethanol is trash. it causes more problems with engines than any fuel. If it sits, it separates from the gas and causes fuel pumps to seize up all so fuel injectors to gum up and stick on some overhead cam motors like the 4.6 ford the valves will stick and the pushrods will fall and cause major work even on a new engine.

This fuel causes so much damage to motors it should be outlawed. The companies putting this garbage in our fuel are making money using it as a filler and they make money.

The consumers are spending hundreds of millions of dollars a year fixing their motors and we the people are the ones replacing injectors, plugs, gas tanks, fuel pumps, fuel lines, doing major head work and replacing their motors because of the damage caused by ethanol.

I would rather pay more for gas without the ethanol. I have spent thousands of dollars in the last couple of years on ethanol damage to my cars. I am only one person. the gas companies and mechanic shops are getting rich from this garbage used as a filler like sawdust in a hamburger. We are told how good this ethanol is. I say it's good for nothing and needs to be discontinued forever.

It has one reason and that is for the gas companies to make more money and as a result we the consumers lose one of our greatest investments and that is our car. look in an auto parts store at all the additives they sell to help clean and protect your engine from ethanol damage. There are tons of them and i have not found any that work. You best never let a vehicle, lawnmower or boat sit with ethanol in it any length of time. If you do, get ready to break the check book out.

We need the option to buy gas without ethanol in it. If it is so good go to the airport and see if they put it in their planes. If they did they might crash when the fuel quit pumping. I say get rid of ethanol. It is a problem fuel that is used as a filler and money maker. Gas, gas, gas, gas only!


@ Fiorite - You make a good point about the economic impact petroleum subsidies have on ethanol, but I believe for ethanol to truly become a sustainable source of liquid fuel, it must be produced from non-competing crops. Corn is unsustainable because of the amount of fuel per acre, and the fact that more than half of the American diet relies on corn. Most cellulosic waste is unsustainable because it prevents those nutrients from being recycled back into the soil. If we take all of the corn waste and make fuel out of it, we will have nothing to left to till back into the farmland to protect topsoil. The best ethanol crop is going to be a hardy plant that can grow in marginal lands. Crops like hemp and switchgrass are able to grow in soil that is devoid of most nutrients, and they yield large amounts of biomass per acre.

Many argue that processing these types of biomass is not economically viable, but there have been a couple of large enzyme makers that have come up with cheap and effective enzymes that are commercially available. These enzymes can process cellulosic biomass like switchgrass, hemp, and agricultural waste all for around 50 cents per gallon. This will allow cellulosic ethanol to cost roughly the same price as gasoline. These second generation biofuel's will also have a better net energy efficiency than gasoline or corn ethanol.


The only reason that ethanol is so much more expensive than gasoline is because the price of petroleum based fuels is artificially deflated due to tax credits and subsidies. First generation biofuels may not be the cleanest fuels, but they still beat out gasoline. Researchers at the Argonne national laboratory found that it takes approximately three BTUs of energy to produce four BTUs of corn ethanol. Gasoline, on the other hand, takes five BTUs of energy to produce the same four BTUs. Although the net energy from ethanol production is greater than that of gasoline, gasoline is still cheaper.

The economics of ethanol production will not improve until there are significant changes made to American energy policy. The practice of using policy to protect a mature industry like the petroleum industry needs to be changed. If anything, economic policies should be created to protect American industries in their infancy.

The main goals of domestic fuel production are to increase national security, bolster the U.S. economy, mitigate environmental problems, and help the nation become energy independent. How can this be accomplished if taxpayer subsidies are funneled into developing overseas oil and gas reserves? This does nothing for the American economy except stifle innovation, and creates long-term price instability in the energy market.

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    • Sugar cane can be used to make ethanol.
      Sugar cane can be used to make ethanol.
    • Ethanol is made from corn in many places.
      By: rimglow
      Ethanol is made from corn in many places.
    • A globe showing the Caribbean, where lots of sugarcane is produced and made into ethanol.
      By: Anton Balazh
      A globe showing the Caribbean, where lots of sugarcane is produced and made into ethanol.
    • Brazil has been at the forefront of adopting ethanol fuel.
      By: Bastos
      Brazil has been at the forefront of adopting ethanol fuel.