Which presents a more evironmentally friendly alternative, ethanol or hydrogen?

Answer 1

You failed to specify how each substance would be used.
Are we to assume they will be used as a fuel for an automobile? Or perhaps they are just sitting in a bottle on shelf?

The combustion of ethanol and Oxygen gas (ideally) products Carbon Dioxide [a green house gas] and water vapor.
The combustion of Hydrogen gas and Oxygen gas produces only water vapor as the result.

Between the two, Hydrogen would seem more environmentally friends when combusted. But one needs to consider how each substance is produced.

Ethanol is made by fermentation of sugars. The process is rather easy and can even occur naturally if the conditions are right. A range of substances can be used as the sugar base for the ethanol fermentation...corn, sugar cane, potatoes,
Then all one needs to do is distill it.
Hydrogen gas can also be produced a number of water. Electrolysis of water (producing H2 and O2) is one very common method, but on a large scale, producing Hydrogen gas by cracking it out of Hydrocarbons is used as well.

Storage is also an issue.

Ethanol is rather simple to store as it is a liquid at room temperature. Hydrogen on the other hand can be quite difficult to store on a large enough scale to be useful since it is such a light gas with such a low boiling point.


In ALL cases, it will ALWAYS take more energy to produce the fuel than the fuel will deliver when burned; this is a basic law of physics, not a property of a few types of fuels.

Both Hydrogen gas and ethanol have their place when used as an alternative fuel. Ethanol meets a more immediate demand while Hydrogen might, someday, be a more permanent and "better" solution in the long run once the kinks are worked out.

Answer 2

For the present Ethanol. Once you already have ethanol and hydrogen in their final useable form, hydrogen would certainly be better since its only byproduct is water. In the production of hydrogen you are essentially loosing energy. Hydrogen useage would have some benefit even now by displacing pollution from heavily polluted areas to a production facility. That said in the end hydrogen ends up involving the creation of more pollutants then ethanol for now.

Answer 3

Currently ethanol, because hydrogen takes more energy to produce and contain than ethanol. Making ethanol is an energy producing process, ie. you get more out of buring it that in costs in energy to produce. Hydrogen takes more energy to produce than you get back out of it by burning it. This may change with future technology, but I would not hold my breath waiting for it.

Answer 4

Hydrogen.

Ethanol has carbons and hydrogens which react with the oxygen to produce carbon dioxide (greenhouse gas) and water.

Hydrogen's byproduct is pure water.

Answer 5

obviously H2 only..
but some risks r there with H2..have to over-come from those.