Ethanol as a Fuel for Our Automobiles
Ethanol as a Fuel Source for Automobiles
This hub explores the subject of the bio fuel, ethanol. Where do we get ethanol? how is it utilized in fuel? why has it been chosen as the primary bio fuel? These are questions dealt with here as well as the positive and negative aspects of ethanol as a fuel source in automobiles.
Ethanol Plant in Turner County, South Dakota, United States
Mankind Still Burns Material in Order to Produce Energy.....Just like Cavemen Did
As I write this article, I am more or less neutral on the subject of ethanol being used as an automobile fuel. Ideally I’d like to see mankind get to the place where we aren’t burning stuff to get our energy. In that regard we haven’t progressed one bit since a caveman first saw a tree get struck by lightening and took a piece of the burning timber home so he could heat the cave and cook his dinner.
Bio Fuel Field
The Source of Ethanol
Ethanol comes from feedstocks, the edible parts of plants such as corn and other grains as well as sugar cane. As these feedstocks go through the processes of fermentation, distillation and dehydration they become ethanol. The same ethanol that winds up in a shot glass ends up in a gas tank.
Current Use of Ethanol in Our Gasoline
We’ve all seen the signs on gas pumps that inform us there is up to 10% ethanol in the fuel we are currently pumping. Notice it says “up to 10%." It could be 0 or 10 or anywhere in between. Ten percent is the legal, upper limit for light duty vehicles in the United States. It’s 10% in Finland, France and Germany as well. Sweden permits 5-15%. The rest of the EU allows five percent.
There are vehicles, mostly in federal government fleets, that run on E85 fuel, or fuel that is 85% ethanol and 15% gasoline.
An ED95 fuel also exists, but it does not contain gasoline. It is 95% ethanol with performance improvers and a denaturant added. That fuel is used in modified diesel engines.
In the United States, the federal Renewable Fuel Standard (RFS) requires fuel refineries to blend ethanol with their gasoline. They do not mandate a certain percentage, but require the blend to approach ten percent.
Ethanol Fuel Mixtures for USA, Europe and Brazil
Why Is Ethanol Considered to be a Good Energy Source?
But why has ethanol even been considered as a viable source of energy, even as a replacement for gasoline in automobiles? Ethanol combusts at a cooler temperature and has a higher octane rating. The octane rating refers to how much a fuel can be compressed before it ignites via the compression rather than by the spark from the spark plug. This causes a miniature explosion, or engine knocks in the cylinder which can damage the engine. The more pressure the fuel can withstand, the more power it can deliver. Ethanol will produce more power and less engine knock than gasoline because of its higher octane rating. And it does this as it burns at a cooler temperature. These two points, cooler combustion and higher octane rating leading to a higher compression ratio are what make ethanol a desirable fuel.
USPS E85 fuel, St Paul, Minnesota
Does Ethanol Pollute the Air?
More engine power may sound like it comes with a price. Does ethanol pollute the air when used as a fuel for automobiles? The alcohol itself burns completely. There is very little pollution in that regard. But alcohol is never absolutely pure. There are contaminants which pollute the air when ethanol is used as a fuel for automobiles. These contaminants are formaldehyde and acetaldehyde. The bottom line is that these pollutants produce smog, especially in large cities with a lot of automobiles in a confined area. Surface ozone levels also increase. Ozone filters harmful solar radiation when it is way up in the stratosphere. But near the surface of the earth it is harmful if breathed. So ethanol power does not come without a price. http://en.wikipedia.org/wiki/Ethanol
Ethanol Plant in West Burlington, Iowa
Ethanol and Auto Manufacturer Engine Warranties
AAA claims that a proposed 15% ethanol/gasoline blend will seriously damage millions of automobiles across the U.S. They also report that the warranties by auto manufacturers would be void if E15 was used in one of their cars.
The Future of Ethanol as a Fuel Depends on New Technology
What does the future hold for ethanol as a fuel for our automobiles? As automakers design engine parts that can withstand the high corrosive effect of ethanol, higher percentages of ethanol to gasoline can be used. Eventually there is the possibility that the average automobile could run only on ethanol. The one thing preventing that from happening is the corrosiveness of alcohol on engine parts.
Currently ethanol is being used as an additive to gasoline. Research is being done that involves holding gasoline and ethanol in separate tanks in vehicles. The two fuels are then injected into the cylinders separately. During low power and low compression performance, only gasoline would be injected. During high power, high compression performance, ethanol and gasoline would be injected, taking advantage of the properties of ethanol. This technology would combine the strengths of both fuels. Ethanol has the added benefit of holding more oxygen which reduces engine knock which has already been discussed in this article. This would be a much more efficient use of ethanol in combination with gasoline. http://en.wikipedia.org/wiki/Ethanol_fuel#Air_pollution
Feedstocks are the current source of ethanol, but great headway is being made to produce ethanol from the fiberous parts of plants called cellulose.
The Negative Side of Ethanol
- Low atmospheric levels of ozone.
- Aldehydes as pollutants.
- Farm land used for energy production rather than for food.
- Depletion of farm soil of innate nutrients for plants.
The Positive Side of Ethanol
- Combusts at lower temperature causing engine parts to last longer.
- Carries more oxygen than gasoline which creates less engine knock.
- Has a higher octane rating which leads to greater power per gallon.
- Does not add carbon dioxide to the atmosphere as a result of burning.
- Comes from plants which means it is a renewable resource.
Still on the Fence
Still on the Fence
Here I am at the end of this article, and I haven’t swayed myself either way. I’m still on the fence when it comes to the use of ethanol as a fuel for automobiles, but I am hopeful that technology will solve some of the negatives. It would be a great thing for our planet if we had a renewable resource from which to produce our energy needs. I for one am still hoping for the day when we don’t have to burn stuff to produce energy. It would be nice to leave that in the past with the cavemen.