Thickening of Gasoline upon long term storage

[Frenemy90210]

Once I had stored Petrol (Gasoline) in a airtight 1 liter plastic container for 6-8 months. When I opened the container, Gasoline had become a thick brown gel. Is it reusable ? Is it still Gasoline or it has become something else ? Thx

 

[Borek]

It will still burn, but I would not put it into the engine.

If it was in the plastic container two things come to mind. First, lighter hydrocarbon fractions can seep (not sure if that's technically the best word to use) out through the plastic. Whatever is left will be thicker than the original mixture. Second, depending on what the plastic was, some of it could dissolve, changing the liquid viscosity.

 

[Asymptotic]

How certain are you that the container was air tight?

Brown discoloration suggests oxidation, thickening into a gel indicate the more volatile constituents have evaporated, and both phenomena in combination point toward less-than-airtight storage.

 

[256bits]

How certain are you that the container was air tight?

Brown discoloration suggests oxidation, thickening into a gel indicate the more volatile constituents have evaporated, and both phenomena in combination point toward less-than-airtight storage.

Are you saying that when gasoline hydrocarbons evaporate there is a residue left behind?
I am also wondering about the "oxidation" chemical reaction.

 

[Nidum]

Was there any change in volume of liquid in container ?

Any change in smell compared to normal gasoline ?

Any damage to container ?

Any sign of pressure in container having been higher or lower than atmospheric - sides ballooned out or sucked inwards?

Any organic residue ? (Moth soup can be quite glutinous sometimes) .

 

[Asymptotic]

Are you saying that when gasoline hydrocarbons evaporate there is a residue left behind?
I am also wondering about the "oxidation" chemical reaction.

Yes. When volatile, short chain hydrocarbons evaporate away what remains are the more viscous, longer chain hydrocarbons.

Read this article on The Straight Dope for a gloss of what occurs. Google "gasoline oxidation reaction" if you are interested in the details..

 

[256bits]

I

Yes. When volatile, short chain hydrocarbons evaporate away what remains are the more viscous, longer chain hydrocarbons.

Read this article on The Straight Dope for a gloss of what occurs. Google "gasoline oxidation reaction" if you are interested in the details..

OK.
I have never known standing gasoline to completely turn to a gel like consistency over time.
That is certainly not projected as being a long term storage problem from the industry.
Ethanol blend, water or other contamination, bad batch.
Varnish deposits and resin formations, but that was a small percentage of the total volume.
Oxidation and polymerization age the fuel but to what extent and time frame.
https://www.intechopen.com/books/st...ing-processes-in-long-term-storage-conditions
http://chemed.chem.purdue.edu/genchem/topicreview/bp/1polymer/reactions.html#cationic

 

[Asymptotic]

I

OK.
I have never known standing gasoline to completely turn to a gel like consistency over time.
That is certainly not projected as being a long term storage problem from the industry.
Ethanol blend, water or other contamination, bad batch.
Varnish deposits and resin formations, but that was a small percentage of the total volume.
Oxidation and polymerization age the fuel but to what extent and time frame.
https://www.intechopen.com/books/st...ing-processes-in-long-term-storage-conditions
http://chemed.chem.purdue.edu/genchem/topicreview/bp/1polymer/reactions.html#cationic

I've never had a problem with E10 gasoline and 2 cycle mix stored over the winter in plastic gas cans located in a cool, dark place, and have seen severe gelling happen only once, and only through mischance. Several years ago in late fall I had been mixing 2 cycle engine oil with gasoline, and accidentally left approximately 100 ml of gas in an exposed beaker in an unheated shed - by the time spring rolled around it had gelled up pretty well.

That's why I'm wondering whether the OP's container is truly air tight, or come to think of it, possibly stored where it is exposed to direct sunlight.

 

[hilbert2]

I think it's almost certain that some of the plastic has dissolved in the gasoline, gelifying it. I've seen plastic containers dissolve because of acetone, and even aniline (which really isn't the most nonpolar solvent you can think of).

 

[Frenemy90210]

Was there any change in volume of liquid in container ?.

Yes. Around 90 % reduction.

Any change in smell compared to normal gasoline ?.

Yes. Smell had almost gone and whatever smell was remaining, was different.

Any damage to container ?.

Nope.

Any sign of pressure in container having been higher or lower than atmospheric - sides ballooned out or sucked inwards?.

Little bit of inward sucking.

Any organic residue ? (Moth soup can be quite glutinous sometimes) .

Nope.

Gasoline was of a standard variety not the high-octane one. I am sure container was airtight. Container was not exposed to sunlight.

 

[TeethWhitener]

@hilbert2 and @Borek are almost certainly right: some plasticizer leached out of the bottle and that's what you're observing.

Edit: just to be clear, over 6-8 months, you only need the container to be just a tiny bit "not-airtight" for everything volatile inside to evaporate.

 

[Mr lee]

never had the issue, even in my antique barn finds. not till ethanol came about.

 

[zbikraw]

Gasoline is "one (or single) fraction" from distillation on large industrial column. Hard to believe it could be fractionated during evaporation through improper sealing of container. When consider oxidation reactions, remember that gasoline consist mainly of parafin hydrocarbons. "Par affinos" means "without affinity" to common chemicals, read "non-reactive" in ambient conditions. Minor components of a gasoline are mainly aromatic hydrocarbons, also nonreactive in room temperature. One can expect trace amounts of olefins and heteroaromatic compounds, also hard to react with oxygen at room temperature. Ethanol added is also nonreactive without catalyst. Oxidation of these classes of compounds is catalytic reaction, hard to believe you have catalyst in your plastic can - polymer additives are (or should be) without such reactivity. Of course, burning of gasoline is oxidation reaction, but it needs activation by flame temperature.
Polymerisarion of unsaturated components of gasoline (aromatics, heteroaromatics, olefins) is frequently observed during action of tourist burner (flame close to gasoline container) and manifests itself as non-flammable residue in container, sometime gelaous. Without high temperature and pressure it strongly needs catalyst, and in commercial plastics traces of catalysts are highly dispersed, hard to meet at surface.
Gelation of a gasoline is known in the Napalm production, and sodium palmitate is similar to some products in plastics deterioration and plastics additives.
Best regards.