With fuel ethanol, how much is lost to evaporation?

Question

I understand that ethanol has 30% less energy density than gasoline, but I also have other concerns about the amount lost to evaporation. In addition, I wonder what steps can be taken to prevent the fuel from becoming vinegar. While I am optimistic about biofuels, including ethanol and to a greater extent, biodiesel, I do understand the tendency of true believers to understate complications. It doesn't mean that they're not good people. It just means that they're willing to overlook some hiccups in achieving their stated aim. My favorite resource on this topic is http://journeytoforever.org/biofuel.html , but I don't see this question answered there.

Thanks, Vincent and N. I'm more knowledgeable about politics and the politics of technology than about the formation of one of my favorite condiments.

To the "top contributor", well, that's not entirely true, and is false in many areas. In Brazil, people have the option of using a B100 ethanol, and plenty of people make their own. However, for commercial availability in the U.S., you're correct in most, but not all, areas that sell ethanol and blends.

Answer 1

Ethanol is more volatile than gasoline, and when mixed the vapor pressure of the mixture is higher than for the gasoline alone. So yes, there will be higher VOC losses to the atmosphere for ethanol/gasoline blends than for gasoline alone.

Vinegar is not a problem as neither fuel grade ethanol or ethanol/gasoline blends will support the growth of the necessary microorganisms.

Answer 2

Not only is Alcohol less useful than Gasoline, but Alcohol by volume causes more pollution than gasoline, and depends on a greater oxygen usage. Alcohol should be banned as an environmental hazard! The real problem is that the Gasoline or internal combustion engine wastes more energy than virtually any other energy using device on the planet . Diesel engines are `also very wasteful and damaging. Electric motors are the wave of the future, and new processes are now being developed that will make electrics the future. Never buy another Gas or diesel vehicle!

Answer 3

You do not have much to worry.
Fermentation that turns alcohol into vinegar is the result of bacterial activity; and bacteria would not survive in an environment that is 100% ethanol, as they need water and other compounds in trace amount to survive, compounds that are not present in pure alcohol (in vinegar fermentation, the "mother of vinegar" -- a mixture of various by-products or left over stuff from the original alcoholic fermentation, with cellulose among other things -- has to be present for the alcohol to turn into acid).
As for the evaporation issue, well, gasoline is also pretty volatile, the key point is thus to keep the liquid in closed containers, just like for gas, to limit evaporation.

Answer 4

Bio Fuels are blended with conventional fuels.