Petrol Storage
 

I am doing some preliminary research for a post-apocalyptic scenario and I know that refined petroleum products have a definite (and short-ish) storage life before they become unusable (unless you add restorative chemicals) ...

Petrol (Gasoline) I've seen quoted online as having a storage life of 3, 6 or even 12 months (6 months seems to be slightly more common than the 3 or 12 month data points).

Diesel storage life seems to be the same.

How about things like Kerosine or Alcohol (methanol and ethanol)? Or other common fuels.

And how about biodiesel like canola or soybean? I am guessing they also become unusable over time ... but I can't find any data (I probably don't know enough to input the right keywords into Google search) online.

Does anyone have any first hand knowledge (or can anyone point me in the direction of some usable online data)?

Also, assuming no chemical conditioners or restoratives are available to reconstitute fuel that has passed its use by date, can it be recovered in other ways (re-refining it, for example)?

Phil McGregor
(Road to Armageddon, Orbis Mundi2)

In a sealed container, kerosene stays good for a really long time (multiple years). The one problem it might have is absorbing water, so it should be filtered.

If they're in sealed, UV-proof containers, ethanol and methanol last just about forever as far as I'm aware. Again, absorbing atmospheric water is a potential problem.

The National Biodiesel Board recommends using biodiesel within 6 months of when it's refined. I've seen suggestions that that's a worst-case scenario for hot, humid environments and it'll last longer in cold, dry environments, but I haven't seen numbers.

Kerosene and the alcohols are most likely to be spoiled by water, so either a water-absorbent filter or (for the alcohols) re-distilling should get them back to normal. Biodiesel and petro fuels I'm not familiar with any restoration techniques.

Well, that's a bit more than I had been able to find by myself ...

Anyone know about vegetable oils?

Phil
(Road to Armageddon, Orbis Mundi2)

I've had cars sitting idle for years have no problems with fuel that was left in the tank. In fact never have I encountered a situation where fuel has been a problem even after 5+ years.... :/

What sort of climatic conditions?

I presume cold temperate which would minimise the loss of the volatile components which is, I assume, what causes the problem?

Phil
(Road to Armageddon, Orbis Mundi2)

Not at all. Winters no colder than -4 C on rare nights, and daytime max of low teens. Summers about 7-8 overnight to mid 20's on average, low 30's on a few hotter days.
Had the same in warmer climates too (add about 10 degrees).

Humidity is the big killer for petro-fuels, being hygroscopic they want to absorb water. From what I understand (and that ain't saying much!), colder weather is certainly helpful but humidity is more of a problem than temperature (except for extremes of hot weather).
I vaguely recall some account of fuel stored in Antarctic or Arctic (can't remember which) research stations, that lasted well beyond it's normal lifetime - specifically because of the very low humidity level in that part of the world rather than being due to the colder weather.

Like Legbreaker, I've had petrol last longer than expected. I have a slow growing lawn that gets the lawnmower once every 6-8 weeks so I have petrol sitting in a Jerrycan for anything up to half a year or more without problems. But aside from lower humidity where I live for most of the year, I suspect the fuel blend and also volume in storage plays a part as well (although again, I'll profess my ignorance and say these are just a guesses on my part rather than any real knowledge).