Hey there, time traveller!
This article was published 9/8/2012 (1720 days ago), so information in it may no longer be current.
Gasoline is the automobile fuel of choice, but it might have been different -- when the Model T was designed, Henry Ford expected ethanol to be the major automobile fuel.
Gasoline took the lead both because of the ease of operation with the existing technology, and the ample supply provided by increased oilfield discoveries. Now, provincial and federal governments are looking toward ethanol production, and the second-fiddle fuel is set to make a comeback for a variety of reasons.
First of all, while gasoline supplies are limited, ethanol is a renewable resource. More than five billion litres of ethanol are used in gasoline in Canada and the United States each year. This represents about one per cent of the gasoline volume. Most of the ethanol is used in "low-level" blends of five- to 10-per-cent ethanol in gasoline.
Wheat, corn, and even wood chips are being used to produce ethanol. Grains are processed with enzymes and the "mash" is distilled to produce a high-quality alcohol. Fuel-grade ethanol is about 99-per-cent pure alcohol and it's an excellent fuel additive for automobiles. By-products of the fermentation process are also valuable and include carbon dioxide, corn oil, high fibre/protein food additives (from wheat), and high-protein animal feed supplements.
There is an energy gain in the production of ethanol and its by-products. After calculating the energy needed to grow the raw materials and produce the ethanol, there is a net energy gain of 151 per cent.
This brings us to the second advantage of using ethanol as a fuel -- the environment. Ethanol is made of 35-per-cent oxygen and, when it is blended with gasoline, it encourages a more complete combustion. A 10-per-cent blend of ethanol with gasoline results in a 25- to 30-per-cent reduction in carbon monoxide emissions. Compounds such as carbon monoxide, benzene, nitrogen oxides and unburned hydrocarbons react with sunlight to form ground-level ozone.
This type of ozone reacts with sunlight to cause smog, and is not to be confused with ozone in the stratosphere, which is beneficial. Smog causes human respiratory problems and damages plants. The benefits of using ethanol include a substantial reduction in emissions that contribute to ground-level ozone -- carbon monoxides in particular.
As a fuel, ethanol burns cooler than gasoline. This reduces emissions, cleans and prevents engine deposits, and acts as a gas-line antifreeze. It also raises octane levels. At 10-per-cent blends, ethanol has an octane rating of approximately 94, which translates into performance. Race-car drivers have used ethanol for years as a performance fuel because of its high octane value.
All major auto manufacturers warrantee their vehicles for the use of E10 (10 per cent ethanol/ 90 per cent gasoline) and all automobiles made since the 1970s can use up to 10 per cent ethanol without requiring engine modifications. Some manufacturers allow an ethanol blend up to 15 per cent. Ethanol-blended fuels are readily available at about 1,000 service stations across Canada, in proportions of five- to 10-per-cent ethanol with gasoline. A few new vehicles are E85 compatible. That means they can use a variety of ethanol/gasoline mixtures up to 85-per-cent ethanol. While E85 fueling stations are currently limited to the central U.S., this next step will see even more benefits from ethanol fuel.
Don't confuse ethanol with methanol. Although both are alcohols, methanol is very corrosive and special fuel-system components are needed to operate on methanol. Most of the fuel system needs to be built using stainless steel. Many auto manufacturers do not warranty vehicles using methanol, while some do allow minimal amounts, from three to five per cent by volume.
Ethanol has a couple of disadvantages as a fuel. Currently, it's still slightly more expensive per litre to produce than gasoline, although the ethanol by-products offset this expense. As the price of gasoline increases, this disadvantage will disappear.
Ethanol doesn't ignite as well as gasoline at very low temperatures. This is overcome by blending it with gasoline. Ethanol has less energy per litre than gasoline, but if automobile engines are designed to take advantage of the higher octane level, the fuel economy and performance is similar.
Another major disadvantage is the possibility of phase separation. If excessive water is absorbed, a phase separation occurs, leaving a mixture of alcohol and water in the bottom of the tank. This causes poor engine operation and can cause corrosion in fuel-system components. Keeping fuel tanks sealed and storing fuel properly minimizes this disadvantage.
Ethanol has a cleaning effect on fuel tanks and fuel systems. Rust, corrosion and dirt in the vehicle fuel tank or in bulk storage tanks will come loose and plug up the fuel filters. Older tanks may need to be cleaned or replaced, or the fuel filter may have to be changed a few times until the tank is clean.
Finally, there are economic benefits of increased ethanol use. Agriculture will have a larger market for their produce. Jobs will be created in the production and distribution of ethanol. Dependency on offshore oil supplies will decrease. In the future, fuel-cell vehicles will need a supply of hydrogen, and ethanol is an excellent renewable source of hydrogen.
The future of ethanol as a fuel appears secure.
Jim Kerr is an experienced mechanic, instructor of automotive technology, freelance journalist and member of the Automobile Journalists' Association of Canada.