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Old 05-13-2009, 01:39 PM   #16
Oracle
 
Drives: Ford Focus
Join Date: Jun 2008
Location: Phoenix, Az
Posts: 71
Quote:
Originally Posted by theholycow View Post
I don't use acetone (as I mentioned above) and am a skeptic, but I think there's a few things to address here...



Are you suggesting that gasoline is not ridiculously volatile?

Does anyone know if there's a measure of volatility?



Do you have a car that doesn't have a sealed fuel system with evaporative emissions control? Fuel vapors go into the charcoal canister and end up getting burned in the engine.



Worse than ethanol? Ethanol is 10% of your gas.

Worse than methanol, too? If you somehow manage to have water in your gas, you put Drygas or HEET in, which is (usually) methanol, whose purpose is specifically to absorb as much water as possible.

Any water in the air in your gas tank is going into your engine, whether it goes through the ethanol that comes in your gas, any additive you put in, or if it just condenses and gets sucked into the fuel pump without binding to something flammable. You want it bound to something flammable (like ethanol, methanol, or acetone if you're one of those silly people who would try acetone).
I appologize, my first post was based on assumptions and experience. I took the time to test my hypothesis (slow day in the lab). to measure volatility i measured out 10 mL of both gasoline and acetone (regular ace hardware stuff we use as a cleaning solvent). I poured both samples into a petri dish and let sit and vaporise. the idea is that the more volatile one will evaporate faster. The Acetone evaporated out in approx. 25 minutes. the gasoline is still at it and has enough that it can cover the entire bottom of the dish and slosh around. clearly acetone is significantly more volatile

Yes my fuel system is sealed. every fuel system is. gasoline would evaporate right out of your tank if it wasnt. instead though it vaporises untill the environment becomes saturated. since acetone is more volatile than gasoline its going to vaporise faster, meaning your going to have a high concentration of acetone vapors. sure it will still be burned, but its not going to take a whole tank of gas to burn it out. like i said, i predict it being useful for less than 1/4 of a tank... and thats if you drive it straight.

As per the ethanol being more hydrophillic? i cant say conclusively. I ran a Karl-Fisher titration for water on the acetone. this is the method we use to detect water in ethanol. currently its reading 2.42% water and still climbing. as reference EtOH usually peaks at .56% water from environment absorbtion. the reason i cant say conclusively is that the titration is still going after almost an hour. normally its a short 5 minute test, leading me to beleive acetone is somehow interupting the detector... so really i cant say if it really has a high ammount of water or if its detector is botched.

Water doesnt compress very well, doesnt combust, and doesnt have a negative net effect on heat like the chemical reaction of combustion does. to get water out of your gasoline yes you want it absorbed... but if ther is no water i wouldnt want to bring in unnecessary water from the environment, ya know?
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