gasoline

B

Bubsyouruncle

Senior Member
Watched several utubes on eliminating ethanol from pump gasoline.


Aside from the flammability aspects, comments. Like, does it work?
 
I read that the ethanol is part of the octane rating, so you have less octane and fuel when you are finished.
 
I know nothing about the science of gasoline. I do know from personal experience we use ethanol free gas in the '32 (33 engine) and all our auxillary lawn care equipment, etc. Because they tend to sit for months on end without use we don't worry about degradation and varnish etc. They always fire right up and run just fine. Perhaps if one required higher octane for a higher compression engine or performance this gas may not be the best. Don't know but would be very interested to hear more on the science on this thread. The ethanol free gas is more expensive but given it is used far far less than daily drivers the cost difference is insignificant.
 
This subject was addressed on, I believe, the H.A.M.B. several month ago. The general consensus (backed up with some good data and examples) is that it is labor intensive and ineffective at best and downright dangerous in any case

I live in the "Lake Country" in North Central Minnesota, and ALL of the gas stations (even the ones at the supermarkets!) have "non-oxygenated" (no alcohol) gas.
 
If there are boats or farm equipment around there should be non-ethanol gas available. Easy to find around here, it is all I use in my equipment.
 
Yes you can easily force "phase separation" with water. If you start with 92 Super unleaded you end up about 88 octane petrol gasoline. It's a bit of a hassle, but if you can't easily buy Non-ethanol, it is a great alternative.
I can buy non-oxygenated/non-ethanol at about a dozen gas stations in a 15 mile radius of my home so it's not worth messing with it for me.
 
As Tubman said, very dangerous. I also dont think it will be that effective. You will likely absorb as much water into the gas as you get ethanol out. Thermodynamics are against you. I teach chemistry to graduate and undergraduates in my day job.
 
Emmit51 said:
As Tubman said, very dangerous. I also dont think it will be that effective. You will likely absorb as much water into the gas as you get ethanol out. Thermodynamics are against you. I teach chemistry to graduate and undergraduates in my day job.
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Petrol gasoline is very hydrophobic. But since you are a chemistry teacher...
you already know that. Tell me more about gas and water mixing. Have the molecular properties changed recently?
 
Buy the eth and burn it up. Don't let it sit in your car forever. granted I only use non-ox as it's available. Lot of guys use only eth all the time.
 
Emmit51 said:
As Tubman said, very dangerous. I also dont think it will be that effective. You will likely absorb as much water into the gas as you get ethanol out. Thermodynamics are against you. I teach chemistry to graduate and undergraduates in my day job.
Click to expand...


But, as I understand it, gasoline and water do not mix! So how then does gasoline "absorb" water? From what I have read over the years, underground gasoline pipelines get water in them and the water settles out in low areas of the pipeline, and some water gets carried to the terminals where gas is stored in those huge tanks. These tanks have provision for draining off the water that settles out of the gas to the bottom of the tanks. This has been going on since the start of transporting gasoline through underground pipelines.
However, with the advent of diluting gasoline with ethanol, the water accumulation in the pipelines became a big problem because the ethanol would absorb that water and be ruined. So ethanol has to be shipped to the terminal by rail tank cars, which is much more expensive, as well as detrimental to the environment!
 
Emmit51 said:
As Tubman said, very dangerous. I also dont think it will be that effective. You will likely absorb as much water into the gas as you get ethanol out. Thermodynamics are against you. I teach chemistry to graduate and undergraduates in my day job.
Click to expand...


No more dangerous than filling up your lawnmower gas tank!
Here's an idea, taken from your local airport, where a standard preflight operation is draining a sample of fuel from each tank and checking it for water (which always settles to the bottom of the tanks). Failure to drain off the water (usually from condensation in the tanks) often results in a crash. So if you need to easily remove the ethanol for your A, mower, saw, etc., find a tank from a wrecked light plane and mount it in a stand in the same position as it was in the plane so that the sump drain is the lowest point. Add the appropiat amount of water to a five gallon gas can and fill it whenever you fill your daily driver. Shake and add to the plane tank. When it's full, wait a few days and drain off the ethanol/water sludge. Presto! Non-ethanol gas! Leave the plane tank outside. After all, airplanes often sit outside.
 
40 Deluxe said:
No more dangerous than filling up your lawnmower gas tank!
Here's an idea, taken from your local airport, where a standard preflight operation is draining a sample of fuel from each tank and checking it for water (which always settles to the bottom of the tanks). Failure to drain off the water (usually from condensation in the tanks) often results in a crash. So if you need to easily remove the ethanol for your A, mower, saw, etc., find a tank from a wrecked light plane and mount it in a stand in the same position as it was in the plane so that the sump drain is the lowest point. Add the appropiat amount of water to a five gallon gas can and fill it whenever you fill your daily driver. Shake and add to the plane tank. When it's full, wait a few days and drain off the ethanol/water sludge. Presto! Non-ethanol gas! Leave the plane tank outside. After all, airplanes often sit outside.
Click to expand...
Probably a lot easier to find and use an automotive fuel tank with the drain plug in the bottom (virtually all vehicles had them)
My old Piper J3 did not have one in the fuel tank.
And yes, even automotive tanks sat outside.
 
There is a web site, pure-gas.org, that lists stations that offer non-ethanol gasoline by state. While not all inclusive it may give you a place to start. I live in a small town of 2,000 and we have 5 stations the offer real gasoline, one even has dedicated pumps.
 
40 Deluxe said:
But, as I understand it, gasoline and water do not mix! So how then does gasoline "absorb" water? From what I have read over the years, underground gasoline pipelines get water in them and the water settles out in low areas of the pipeline, and some water gets carried to the terminals where gas is stored in those huge tanks. These tanks have provision for draining off the water that settles out of the gas to the bottom of the tanks. This has been going on since the start of transporting gasoline through underground pipelines.
However, with the advent of diluting gasoline with ethanol, the water accumulation in the pipelines became a big problem because the ethanol would absorb that water and be ruined. So ethanol has to be shipped to the terminal by rail tank cars, which is much more expensive, as well as detrimental to the environment!
Click to expand...

Gasoline with ethanol was never transported by pipeline. A small trace of water in ethanol gas makes it milk colored. It is blended at the local pipeline terminal. Ethanol gasoline is also stored in tanks with a domed roof. Gasoline without ethanol is stored in floating roof tanks.
 
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"while conventional gasoline can dissolve up to 150 parts per million of water at 70°F, the situation is different for gasoline oxygenated with 10% ethanol. This 90% gasoline/10% ethanol blend can dissolve up to 7,000 ppm of water at 70°F. When this blend is cooled, both the water and some of the ethanol become insoluble. Contacting the blend with more water also draws ethanol from the blend. The result, in both cases, is two layers of liquid, an upper ethanol-deficit gasoline layer and a lower ethanol-rich water layer. This phase separation of the gasoline/ethanol mix lowers the octane number and may cause knocking in an engine, while the engine will not run at all on the ethanol/water layer." https://petroclear.com/resources/dont-be-phased.php
 
WABOOM said:
Petrol gasoline is very hydrophobic. But since you are a chemistry teacher...
you already know that. Tell me more about gas and water mixing. Have the molecular properties changed recently?
Click to expand...


Yes, gasoline is hydrophobic, but when ethanol is added, it becomes more hydrophilic. "pure" gasoline, which is made up of many types of molecules and additives, absorbs water, but very little. When you mix gasoline with water, they form two layers, but each absorbs a little from the other. There is a small amount of water dissolved in the gas, and a little bit of gas dissolved in the water.



When you add ~10% ethanol to the gas, it gets more complicated. At that percentage, ethanol fully dissolves in gas. Dissolving ethanol in gas makes the gas more hydrophilic, and so if you mix ethanol-gas with water, it will still form two layers, but you will dissolve more water into the ethanol-gas, than you would with pure gas. likewise, you will dissolve some ethanol and more gas into the water (since the water is now more hydrophibic with ethanol dissolved in it).



If you let the 2 layers sit for a while to equilibrate, you will have a layer of gas that is saturated with water and still contains ethanol, and a layer of water/ethanol that is saturated with gas. Even though ethanol is completely miscible with water, you will not be able to remove all the ethanol form the gas. To get close to complete extraction, you would need to repeat the process with fresh water multiple times. Bear in mind that in addition to removing some ethanol from gas, you are also probably removing some other additives, such as detergents as well.


For anyone who does this, aside from the potential hazards of sloshing around gallons of flammable liquid and exposure to vapors, you might also consider what you will do with the water waste that is saturated with gasoline? I hope no one is dumping this "down the drain".
 
40 Deluxe said:
No more dangerous than filling up your lawnmower gas tank!

. Add the appropiat amount of water to a five gallon gas can and fill it whenever you fill your daily driver. Shake and add to the plane tank.
Click to expand...

So what's the "appropriate" amount of water for 5 gallons?
 
Non ethanol gasoline is saturated with water. All the gasoline storage tanks in a refinery have floating roofs and water drains. The floating roof is to minimize evaporation vapor emissions.
But water is a polar(meaning it has an electrical charge on it) molecule and gasoline isn't(being mostly paraffins and aromatics) so there is not much water dissolved in gasoline. BTW ethanol is also a charged molecule(not as charges as water however) which is why water dissolves in it.
 
I checked yesterday, the price of 91 octane 10% ethanol and non-ethanol gas is the same price. So if you can get the non-ethanol don't think attempting to modify 10% ethanol would be worth the effort.
 
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