Friday, September 12, 2008

Alternative fuels, ethanol and vehicles

Alternative fuels are not the brand new topic as many people think they are. There is a long history of different researches by different organizations and individuals that have been constantly researching and hoping to find brand new ways to power vehicles.

When we think about the main differences between the alternative fuels and fossil fuels we mainly think about our environment, as fossil fuels like gasoline, diesel and kerosene have harmful effect on climate change and global warming phenomenon. But there is also life span of fossil fuels meaning that they are not renewable energy sources. Once certain fossil fuel is depleted it doesn't exist any longer. For instance if we ran out the oil we won't be able to create new one, and this is from energetic point of view main reason why we have to turn our attention to alternative fuels. Alternative fuels have this ability to be produced over and over again, meaning that there is no possibility of limited, or even no supply. Some alternative fuels are still subjects of many discussions, for instance biofuels that are normally produced from food sources, waste food products, plants and other organisms that can be replenished and continue to grow where many people think that food shouldn't be source for energy, especially since there are so many hungry people in the world.

Ford Ka with battery driven electrical engine. Electricity is very promising alternative fuel, but battery capacities and recharge times are still not good for everyday car usage.

US market has lately put much more attention to ethanol and biodiesel, especially after oil price became fully unpredictable. Ethanol is an alcohol, usually made out of corn or wheat. Ethanol needs to be mixed with gasoline in order to create a cleaner burning fuel. The only problem here could be the portion of produced gasoline. As long there is an oil things are fine, but once shortages creep in immediately attention is focused to alternative fuels sector. Of course alternative fuels require cleaner production technologies, with significantly less impact on environment than the fossil fuels in order to be ecologically acceptable.

Minimum mixes of ethanol and gas are ranging from country to country starting from two percent to five percent, and in some cases even to ten percent. Some scientists and energy experts believe that that fifteen to twenty percent of ethanol is probably the largest amount that can be mixed without having to physically change the mechanisms that run today's vehicles. Contrary to this opinion today you can even find cars that are being manufactured to take gigantic eighty-five percent ethanol. Of course the most difficult thing here is to start a vehicle with such large percentage of ethanol, because using gas as an igniter is much easier than to use ethanol.

Ethanol is mainly produced from sugar cane, wheat and corn based products but there are many other areas that experts explore. Mesquite, different sweet grasses, vegetable oil, palm oil, soybean oil, recycled cooking oil, and animal fat run-offs are all being researched, some of them with very encouraging results. In case you didn't know there are also some other alternative fuels used for many years like for instance propane that is used opposed to a gas by many delivery trucks, and there are also electric cars.

US are nation that highly relies on vehicles, and there have been a lot of researches that could lead to the development of vehicles powered with unconventional fuels. George Bush's administration for instance invested over one billion dollars to the development of hydrogen powered vehicles, especially in the lightweight cars segment. According to some estimation by the year 2020 there could be about two million hydrogen fueled vehicles on the road.

Hydrogen car at fueling station. Hydrogen fueling stations are still very rare because they are very expensive. Transport of hydrogen is also very expensive, but when all issues will be solved, hydrogen should be the cheapest and the cleanest alternative fuel.


Anonymous said...

So can I mix ethanol with gasoline or not?

mitch said...

Because ethanol provides less energy but has a higher octane content I have the question could the compression ratio be raised to compensate for the power difference.

Davor Habjanec said...

Increasing the compression ratio of your engine is tricky business. Yes, you can compensate the power difference with higher compression ratio, but higher compression ratio can damage your engine (engines and some engine related parts are designed to run on a certain compression ratio and higher compression ratio increases load on engine and those parts).

Other problem occurs when you go back to regular gasoline. Because of higher compression ratio in that case, fuel mix can ignite because of compression rather than spark, and that is not good for the engine.

And also, increasing the compression ratio is very expensive – horse powers are not cheep.

See also:
What does octane mean?