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Save Old Iron

Chemical Engineers - I need your help

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wh500special

When I was a kid, my uncle was some kind of pseudo bigshot at the local army reserve center.  He would bring home practice grenades for the fourth of July and toss them in the lake.

 

KA-BOOM!

 

Fish would float to the surface stunned.

 

Usually just little bluegills and green sunfish, but one year a giant Isreali carp met it's end.

 

Good times...

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wh500special

...met it's end.

 

"its", not "it's"

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dcrage

Chuck

 

I just had a friend ask me a similiar "ethanol in gas; remove it with water" question which has prompted me to dig a little more on how effective water is in pulling ethanol out of gasoline -- The best measure of this property is a value called the "octanal/water partition coefficient"; octanol being a good analog for gasoline -- This value says that ethanol is about 2x as soluble in water as it is in octanol

 

So what that means for the 'video' sample you ran is there is still plenty of ethanol in the gas layer -- If you repeated this exercise adding an equal amount of water to gasoline, the resultant concentration of ethanol in your water level is 2x greater than the ethanol concentration in your gas layer (i.e. the gas ethanol content is about 33% of what came out of the pump) -- Since in your case you water amount is about 1/5 of the gas amount; according to my back of the envelope calculation estimates that you removed about 1/3 of the total ethanol in the original gas sample with that single wash

 

And everyone needs to remember that when doing this washing exercise you are saturating your gas with water (I saw a value of 0.1% today doing a quick Google scan for that value)

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Save Old Iron

thank you sir - very interesting.

 

I should have posted earlier on the success I had with using the 'washed' fuel shown in the video. I was able to siphon out the fuel layer and use it to complete a grass cutting session without incident.

 

I will retry this same experiment using your input. The experiment will be performed on a much smaller quantity of E10 just to proof your theory.

 

:) 

 

             i

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dcrage

Chuck

 

If your intent is remove as much ethanol as you can out of your gasoline; the "chemical engineering" trick is to do multiple washes with smaller amounts of water (i.e. the amount of ethanol remaining in 1 l of gas washed 1 time with 1 l of water would be a whole lot more than the amount of ethanol remaining in 1 l of gas washed 5 times with 200 mL aliquots of water (1 l water total) -- Since Steve (wh500special) is a ChemE; he should be able to do the calculation determine how much difference these two treatments would be in his sleep -- Whereas I would have to stop and really think about it a while

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