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Author Topic: Can I remove ethanol from gasoline?  (Read 8006 times)

Geezer

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Can I remove ethanol from gasoline?
« on: 29/01/2011 20:35:55 »
"Gasoline" in the US includes a significant amount of ethanol, and the amount is going to go up even more, to 15% I think. This gasoline ethanol mixture works reasonably well in automobiles, particularly if the fuel is used fairly rapidly, but it can cause a lot of problems with equipment that is only used intermittently because the ethanol acquires water from the atmosphere, and that water ends up in the fuel.

Is it possible to "wash" the alcohol out of the mixture by adding enough water to dissolve all the alcohol, then separate the water and gasoline mechanically?

Bored chemist

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Can I remove ethanol from gasoline?
« Reply #1 on: 30/01/2011 09:59:31 »
It would be possible but you would have to consider the issue of drying the gasoline afterwards and also the fact that the wash might remove other additives.
Even if the wash didn't remove other anti knocking agents, removing the alcohol would affect the octane rating of the fuel.
It might be easier to ensure that you keep the fuel in an airtight container rather than the fuel tank.
That also gets round the problem that gasoline will change in storage as the more volatile components are lost to the atmosphere.

lightarrow

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Can I remove ethanol from gasoline?
« Reply #2 on: 30/01/2011 12:52:49 »
Maybe it could be useful to put a thin layer of silicon in the mouth of the fuel tank, so that the petrol cap closes it hermetically, if this is the cause of air contact with the fuel.

Geezer

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Can I remove ethanol from gasoline?
« Reply #3 on: 30/01/2011 19:25:03 »
Thanks BC and lightarrow.

I suspect the reduced "octane" level would not be much of a problem as this sort of equipment has low compression ratios.

Maybe the best solution is to only add small amounts of fuel to the tank so that it can be run dry before putting the equipment into storage. It would also help if the manufacturers included a simple means to drain the tank, but I've never seen one that did.

I've heard there is an even bigger potential problem with 2-stroke engines running on gasohol. Apparently, under the right conditions, the lubricating oil that's added to the fuel can separate from the mixture, with disastrous results.

lightarrow

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Can I remove ethanol from gasoline?
« Reply #4 on: 30/01/2011 19:45:11 »
I've heard there is an even bigger potential problem with 2-stroke engines running on gasohol. Apparently, under the right conditions, the lubricating oil that's added to the fuel can separate from the mixture, with disastrous results.
I can confirm it to you: when I added ethyl and methyl alcohol to gasoline for my motocross bike, the oil added reduced the concentration of water that alcohol could have to mix with gasoline+oil fuel: with gasoline only I could add ethyl alcohol with some percent of water; with gasoline+oil the alcohol had to be purer (= dryer) or it didn't mix with the fuel, in the same percent (I had to reduce the percent of alcohol added).

CliffordK

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Can I remove ethanol from gasoline?
« Reply #5 on: 31/01/2011 10:52:46 »
I've heard there is an even bigger potential problem with 2-stroke engines running on gasohol. Apparently, under the right conditions, the lubricating oil that's added to the fuel can separate from the mixture, with disastrous results.
I can confirm it to you: when I added ethyl and methyl alcohol to gasoline for my motocross bike, the oil added reduced the concentration of water that alcohol could have to mix with gasoline+oil fuel: with gasoline only I could add ethyl alcohol with some percent of water; with gasoline+oil the alcohol had to be purer (= dryer) or it didn't mix with the fuel, in the same percent (I had to reduce the percent of alcohol added).
I believe some people have been using biodiesel as a lubricant additive to E-85 or other higher ethanol blends for 2 cycle engine lubrication.  Consider it experimental, but some people have had good luck with it.

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Can I remove ethanol from gasoline?
« Reply #6 on: 31/01/2011 12:56:32 »
I believe some people have been using biodiesel as a lubricant additive to E-85 or other higher ethanol blends for 2 cycle engine lubrication.  Consider it experimental, but some people have had good luck with it.
When I used my motocross bike (~ 20 years ago) I didn't have the possibility to buy E-85 so I used denaturated Alcohol or ethanol for food, bought in the shop. The first had a water percent greater than 10%, the second less than 5%.

 

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