Ethanol fuel

Ethanol is made by fermenting and then distilling starch or sugar crops such as sugar-cane, maize, sorghum, wheat and other grains, or even cornstalks, fruit and vegetable waste.

The benefits

Ethanol is a much cleaner fuel than petrol (gasoline):

• It is a renewable fuel made from plants
• It is not a fossil-fuel: manufacturing it and burning it does not increase the greenhouse effect (see Greenhouse gases and global warming)
• It provides high octane at low cost as an alternative to harmful fuel additives
• Ethanol blends can be used in all petrol engines without modifications
• Ethanol is biodegradable without harmful effects on the environment
• It significantly reduces harmful exhaust emissions
• Ethanol's high oxygen content reduces carbon monoxide levels more than any other oxygenate: by 25-30%, according to the US EPA
• Ethanol blends dramatically reduce emissions of hydrocarbons, a major contributor to the depletion of the ozone layer
• High-level ethanol blends reduce nitrogen oxide emissions by up to 20%
• Ethanol can reduce net carbon dioxide emissions by up to 100% on a full life-cycle basis
• High-level ethanol blends can reduce emissions of Volatile Organic Compounds (VOCs) by 30% or more (VOCs are major sources of ground-level ozone formation)
• As an octane enhancer, ethanol can cut emissions of cancer-causing benzene and butadiene by more than 50%
• Sulphur dioxide and Particulate Matter (PM) emissions are significantly decreased with ethanol.

Backyard ethanol

As with biodiesel, you don't have to be a corporation to make ethanol -- you can make fuel alcohol in your backyard, and many people are doing just that, and running their vehicles on clean-burning alcohol instead of gasoline.

It's more equipment-intensive than biodiesel. You need a still, and you need to learn how to ferment beer. You can build your own still, and there's good information available to help you learn what you need to know.

You'll find everything you need in our Resources section and in the Biofuels Library.

Permits: In the US, home brewers need to get a "small fuel producer" permit from the US Alcohol and Tobacco Tax and Trade Bureau (TTB).

Download the form here:
http://www.ttb.gov/forms/f511074.pdf

Two copies of the application should be sent to the TTB National Revenue Center. The address is:
Alcohol and Tobacco Tax and Trade Bureau

National Revenue Center
550 Main Street, Suite 8002
Cincinnati, Ohio 45202

Tel. 1-855-882-7665
Email: ttbquestions@ttb.gov

Permits are free, and entitle you to make up to 10,000 gallons (38,000 litres) of ethanol fuel at home for personal use per year.

Other countries have similar rules. Contact the national authority in your country and find out what's required.

How does it work?

Ethanol is a very high octane fuel, replacing lead as an octane enhancer in gasoline.

Fuels that burn too quickly make the engine "knock". The higher the octane rating, the slower the fuel burns, and the less likely the engine will knock.

When ethanol is blended with gasoline, the octane rating of the petrol goes up by three full points, without using harmful additives.

Adding ethanol to gasoline "oxygenates" the fuel, adding oxygen to the fuel mixture so that it burns more completely and reduces polluting emissions such as carbon monoxide.

Ethanol and ETBE oxygenator, made from ethanol, are much safer than the toxic and polluting MTBE fossil-fuel-derived oxygenator used by oil companies.

Production

Ethanol fuel production is a good locally-based industry, providing local jobs and a market for local materials, and helping to keep money and investment within the community. That's why so many of the farming states in the US (and Canada) back ethanol fuel.

One ethanol plant owned by farmers in Minnesota processes 11,751 bushels of grain a day to produce 33,990 gallons of ethanol and 95 tons of high-protein livestock feed.

If you happen to have a spare acre in your back yard, you can raise enough maize to make enough ethanol to drive even a 17mpg gas-guzzler about 5,000 miles, along with enough animal feed to help keep you in eggs and chicken.

If the climate favours sugarcane, an acre's worth will take you nearly 15,000 miles. A few fruit trees would help a lot too. You could put the by-product in a digester, along with other organic wastes, to produce methane gas for cooking -- or as a heat source for the distillation process.

Alcohol yield tables (for 30 different feedstocks), showing: Average yield of 99.5 percent alcohol per ton; Average yield of 99.5 percent alcohol per acre.

Energy balance

Ethanol is a highly efficient fuel. A study by the Institute of Local Self-Reliance in the US found that using the best farming and production methods, "the amount of energy contained in a gallon of ethanol is more than twice the energy used to grow the corn and convert it to ethanol".

The US Department of Agriculture says each BTU (British Thermal Unit, an energy measure) used to produce a BTU of gasoline could be used to produce 8 BTUs of ethanol.

The non-profit American Coalition for Ethanol says ethanol production is "extremely energy efficient", with a positive energy balance of 125%, compared to 85% for gasoline, making ethanol production "by far the most efficient method of producing liquid transportation fuels".

See:
Is ethanol energy-efficient?
Food or fuel?

Ethanol resources on the Web

Ethanol -- schools projects
See Biofuels > Biodiesel > Ethanol