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Removing ethanol from E5 and E10 petrol

BlueChip

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I don’t know if this has been covered before but it’s quite easy to wash the ethanol out of petrol by adding water to the fuel and giving it a good shake. The water has an affinity for the ethanol and mops it up. Allow the shaken mix to settle for a few hours until the water layer is at the bottom and the washed petrol is clear. then decant the ethanol free petrol. There are many YouTube videos showing this.
I’ve spent too many hours this year cleaning my outboard fuel system and carb, I’m going to give this a try.
 

MADRIGAL

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12 Jan 2019
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Ma
I don’t know if this has been covered before but it’s quite easy to wash the ethanol out of petrol by adding water to the fuel and giving it a good shake. The water has an affinity for the ethanol and mops it up. Allow the shaken mix to settle for a few hours until the water layer is at the bottom and the washed petrol is clear. then decant the ethanol free petrol. There are many YouTube videos showing this.
I’ve spent too many hours this year cleaning my outboard fuel system and carb, I’m going to give this a try.
I’ve not tried it, but it makes sense to me.
 

TernVI

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Has anyone done this and checked they end up removing all the water they put in, plus 5% of the 'petrol' which was ethanol?
I think it's quite likely the 'clear' petrol will include a lot of dissolved water.

If one did succeed in removing the ethanol from E10 petrol, what would the octane rating of the remainder be?
 

Bouba

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SoF
I personally wouldn’t try that without first setting up a fuel polishing system to run the stuff through. It would also be nice to have somewhere to do this that wasn’t the garden shed.
 

TernVI

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Looks as if the solubility of water in petrol is about 0.015% https://pubs.acs.org/doi/10.1021/ie50139a019
But isn't the alcohol a 'co-solvent?'
I've been told that 'back in the day' people used to add alcohol to diesel, to dissolve unwanted water into the diesel so it would go through the system.

Also doesn't pump 'petrol' contain things like detergent?

This kind of chemistry is not my field.

Feel free to prove it works by ending up with the exact right amount of fuel.

One thing I do know is that there is a lot of nonsense on youtube!
Which is a shame because there is some great stuff too.

When people ran motorbikes on methanol, they used huge main jets.
Methanol has a low calorific value.
So it seems does ethanol:
Fuels - Higher and Lower Calorific Values
So if you remove the alcohol, won't the engine run rich?
 
Joined
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But isn't the alcohol a 'co-solvent?'
I've been told that 'back in the day' people used to add alcohol to diesel, to dissolve unwanted water into the diesel so it would go through the system.

Also doesn't pump 'petrol' contain things like detergent?

This kind of chemistry is not my field.

Feel free to prove it works by ending up with the exact right amount of fuel.

One thing I do know is that there is a lot of nonsense on youtube!
Which is a shame because there is some great stuff too.

When people ran motorbikes on methanol, they used huge main jets.
Methanol has a low calorific value.
So it seems does ethanol:
Fuels - Higher and Lower Calorific Values
So if you remove the alcohol, won't the engine run rich?
If you remove the ethanol I'm sure that this will decrease the octane rating so it is possible that the engine could be damaged by detonation (pre) / pinking / knocking unless one starts off with a high octane fuel, assuming that this contains ethanol as well.

However, I've not seen any of these videos but I do not believe that adding water in such a manner to remove the ethanol is actually possible. I will try and find some of these videos.

Richard
 

pyrojames

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Cambridge
It might run ok for a bit after doing this, but engines aren't that happy running on stuff they weren't designed for. I had a student who decided to run his car (diesel) on left over research grade jet fuel. It ran well for about 600 miles before the lack of lubricants in it killed the fuel pump and injectors.
 

JumbleDuck

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SW Scotland
If you remove the ethanol I'm sure that this will decrease the octane rating so it is possible that the engine could be damaged by detonation (pre) / pinking / knocking unless one starts off with a high octane fuel, assuming that this contains ethanol as well.
I've just checked, and pure ethanol is 113 octane. Which I find interesting, because it shows I was wrong about something: I had always thought that air-cooled Beetles converted to run on ethanol in Brazil had a lowered compression ratio because the fuel was low octane, which clearly it isn't.
 

BobnLesley

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1 Dec 2005
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Aground in Yorkshire awaiting a very high tide
...filled a bicycle pump with petrol ( mixed with a bit of polystyrene), waved it over a lit candle then shot it out of my parents garage.

30 ft of terrifying flames and the fence engulfed and burnt down .......
That's one that I never discovered as a kid; something to try this coming weekend.
 

Zing

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The Northern Powerhouse
Has anyone done this and checked they end up removing all the water they put in, plus 5% of the 'petrol' which was ethanol?
I think it's quite likely the 'clear' petrol will include a lot of dissolved water.

If one did succeed in removing the ethanol from E10 petrol, what would the octane rating of the remainder be?
Yes, I’ve done it and it works at removing it. I did it just to test for ethanol, not to remove it. I have an engine that requires ethanol free fuel.
 
Joined
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29,305
Location
Home UK Midlands / Boat Croatia
If you remove the ethanol I'm sure that this will decrease the octane rating so it is possible that the engine could be damaged by detonation (pre) / pinking / knocking unless one starts off with a high octane fuel, assuming that this contains ethanol as well.

However, I've not seen any of these videos but I do not believe that adding water in such a manner to remove the ethanol is actually possible. I will try and find some of these videos.

Richard
I've looked at a few of the videos and, as expected, some are nonsense but some look sensible and do suggest that if you mix water and petrol then the water phase will increase in volume as it absorbs the ethanol from the petrol. However, apart from the octane lowering issue raised above, none of the experiments explain what other components of the petrol might be being absorbed into the water along with the ethanol.

Richard
 

Freebee

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Joined
21 Oct 2001
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Location
Micheldever, hants
Having had a boat with a GRP fuel tank I was faced with the problem of trying to remove the ethanol, the biggest issue for me was one of safety. its all very well doing this with a jerry can of petrol but if you need 400 litres that's a lot pf processing and a lot of contaminated water to get rid of afterwards. The temptation was to build a pumping rig that would mix the water and petrol but having worked with fuels all my working life I remembered the safety issues, non sparking tools , explosion proof pumps and motors. it all CARRIES HUGE RISK and is against the law I should I think>>> I would advise cation to anybody trying this experiment.
 
Joined
5 Nov 2009
Messages
29,305
Location
Home UK Midlands / Boat Croatia
Having had a boat with a GRP fuel tank I was faced with the problem of trying to remove the ethanol, the biggest issue for me was one of safety. its all very well doing this with a jerry can of petrol but if you need 400 litres that's a lot pf processing and a lot of contaminated water to get rid of afterwards. The temptation was to build a pumping rig that would mix the water and petrol but having worked with fuels all my working life I remembered the safety issues, non sparking tools , explosion proof pumps and motors. it all CARRIES HUGE RISK and is against the law I should I think>>> I would advise cation to anybody trying this experiment.
Disposing of the adulterated water after processing is a frequent references in the videos and accompanying comments with people suggesting that it must be taken to a proper disposal centre. However, this is not really an issue if the adulteration is solely ethanol as claimed. The adulterated water is basically just wine or very diluted spirits or even urine after a very heavy night on the booze and no-one thinks twice about that lot going down the drains.

Richard
 
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