Ethanol is a liquid alcohol obtained from fermenting sugar or starch converted to sugar. In the United States, fuel ethanol is made from grains such as corn, wheat and barley. A small quantity is made on an experimental basis from agricultural cellulosic biomass.

Ethanol is used either as a blending ingredient in fuels or as a main fuel. There are two types of ethanol fuels:

Low-level ethanol-gasoline blends with ethanol concentrations of up to 10 percent. They can be used in today's vehicles and are the main ethanol fuels used.

High-level ethanol-gasoline blends with ethanol concentrations of 60-85 percent. They can be used in special factory-produced vehicles called flex-fuel vehicles (FFVs).

Why is ethanol used in fuels?

Adding ethanol to gasoline increases the octane number - a measure of the fuel's resistance to pre-ignition or engine "knock." As well, ethanol contains oxygen, which allows for cleaner and more complete combustion. This in turn helps the environment.

Developing, producing and retailing ethanol fuels also generates important new activities in rural regions and creates new markets for midwest grains.

How does ethanol benefit the environment?

Relative to gasoline, ethanol fuels reduce greenhouse gas (GHG) emissions that contribute to climate change. Ethanol is made from plants, which absorb carbon dioxide (CO2) during their growth. On a full fuel cycle (i.e. from plant growth to use of the fuel in a vehicle), a 10 percent ethanol-gasoline blend reduces GHG emissions by up to 4 percent if the ethanol is made from grains, and up to 8 percent if it is made from cellulosic biomass. Blends with 85 percent ethanol (E-85) can reduce emissions by 60-80 percent.

Can ethanol fuels be used year-round?

Yes, ethanol-gasoline can be used year-round. In fact, ethanol-gasoline can serve as a gas-line anti-freeze.

Do vehicle manufacturers approve the use of ethanol blends? Does it affect their vehicle's warranty?

All vehicle manufacturers approve the use of up to 10 percent low-level blends in current vehicles and in higher proportions in FFVs. Indeed, several manufacturers now make FFVs that can use ethanol blends of up to 85 percent. This is respected in their vehicle warranty.

Does using ethanol blends affect your vehicle?

Ethanol helps maintain cleaner engines and helps clean out the fuel-injection systems. Since ethanol can loosen contaminants and residues in the fuel system, this may require changing your vehicle's fuel filter more often. Since 1985, detergent additives have been used in all ethanol blends and nearly all non-ethanol gasolines.

This helps prevent injector deposits. As well, ethanolgasoline does not adversely affect the vehicle's engine or its components.

Can ethanol-gasoline be mixed with pure gasoline?

Yes, ethanol-gasoline can be mixed with pure gasoline in your vehicle's tank. All gasolines in the US (including low-level ethanol blends) must meet fuel specifications.

What effect does using ethanol fuels have on fuel consumption?

While a 10 percent ethanol blend contains about 97 percent of the energy of "pure" gasoline, the energy loss is partly offset by the increased combustion efficiency of the engine. This could increase fuel consumption by about 2-3 percent. Several other factors influence fuel consumption.

DISTILLER'S GRAIN


What is distiller's grain?

Distillers Grain is an important co-product of dry-mill ethanol production. The dry-mill ethanol production process uses only the starch portion of the corn, which is about 70% of the kernel. All the remaining nutrients – protein, fat, minerals, and vitamins – are concentrated into distillers grain, a valuable feed for livestock.

What is the difference between dry and wet distiller's grain?

Dried distillers grain (DDG) is the most common variety. Drying the distillers grain increases its shelf life and improves its ability to be transported over longer distances. If a consistent nearby market can be secured, ethanol producers can supply the feed as wet distillers grain (WDG). The wet form is not as easily transportable, but the cost of drying the product is removed.

What kind of distiller's grain is used in the feed industry?

Dried distiller's grain with solubles (DDGS) is the form available to the feed industry. The liquid that is separated from the mash during the distilling process is partially dehydrated into a syrup, then added back onto the dried distillers grain to create DDGS.

DDGS is a high quality feedstuff ration for dairy cattle, beef cattle, swine, poultry, and aquaculture. The feed is an economical partial replacement for corn, soybean meal, and dicalcium phosphate in livestock and poultry feeds. Historically, over 85% of DDGS has been fed to dairy and beef cattle, and DDGS continues to be an excellent, economical feed ingredient for use in ruminant diets.