Alternative Fuels: A Primer

 
 
By Bill Howard  |  Posted 2006-06-16
 
 
 

Alternative fuels arent a perfect alternative to gasoline. They have less energy than gas and cost more; its improbable that production will be ramped up for more than a fraction of Americas vehicles; they have corrosive effects on normal fuel systems; and its not certain well get the technology to work soon.

Popular Mechanics (May) calculated the cost of driving a small car coast to coast on various fuel sources: It ranged from $60, for an all-electric car using coal-fired powerplants to generate power, to $804, using hydrogen.

Gasoline was pegged at $231 for the trip, although the run-up in prices since the article was written would bring the cost to around $275.

Ethanol, or grain alcohol, is the special ingredient in gasohol (10 percent ethanol, 90 percent gasoline) and E85 (85 percent ethanol, 15 percent gasoline). Its derived from fermenting corn, apples, or sugar cane (maybe Fidel has held on so long by selling black-market E85?) and its also how you make moonshine.

Ethanol fuel mixtures burn cleaner than gasoline, and there are about 6 million flexible fuel vehicles (FFVs) in the U.S.

But ethanol as a primary energy source for all cars doesnt add up: an acre of corn produces 300 gallons of ethanol per season, and all the U.S. ethanol refineries last year turned out 4 billion gallons of ethanol—but Americans burned 200 billion gallons of motor fuel. There isnt enough farmland in the U.S. to grow food, along with the feedstock for ethanol. According to Popular Mechanics youd need to use 675 million of the nations 938 million acres of farmland to make enough ethanol.

In addition, ethanol is corrosive and has only two-thirds the energy of gasoline. Some critics even say ethanol is energy-negative (in other words, more energy is expended farming, harvesting, fermenting, and transporting it than is saved in vehicles), though the Department of Energy says the process is about 35 percent positive.

Methanol is ethanols poor cousin. Also called methyl alcohol or wood alcohol, its poisonous, has only half the energy of gasoline, and is much more corrosive than gas on fuel tanks and fittings.

Methanol can be made from a variety of sources. Most typically, natural gas is converted to methane and then into methanol. But sewage, manure, landfill emissions, coal, sawdust, grass clippings, and other plants can also be used. In FFVs, methanol is mixed with gasoline, often to make M85 (85 percent methanol).

Read the full story on TechnoRide: Alternative Fuels: A Primer

Check out eWEEK.coms for the latest news, reviews and analysis in programming environments and developer tools.

Rocket Fuel