Shelf life of diesel ?

[thewayne]

Hi all,

I like the new forum. Just a question about diesel fuel's shelf life, does anyone know?  I've had some in my tanks for over 3 years and it still fires up but I read somewhere that it will go flat.  I have additives and water remover in it. Once I asked a similar question to Esso about gas and they said "if it smells like gas it is gas"  I had 4 X 45 gal. drums and used them without problems in my lawn tractor for over 4 years and there were no preservatives added at all.

Thanks in advance

Wayne

[mobile_bob]

i don't know how long this new low sulpher diesel fuel is good for, but the older
stuff if kept in a sealed tank, and treated with a good algiecide keeps for 5 years that i know of
and likely longer,, you might have to filter it to get any bugs that want to grow in it out.

somewhere i saw a paper on the long term storage of diesel fuel, iirc they treated it, kept it in
a dark no sunlight tank, at cool and stable temps, and had a draincock that they would drain
once a month to keep any condensation out,, also they would test it for algae and treat it as needed.

my bet is one could keep diesel for a very long time and still have a useable fuel for one of these older
design engines that seem to thrive on just about anything flammable.

might have to mix a bit of kerosene or maybe even RUG to get it to where it is pretty good, if it were left
in very longterm storage.

a question i have been wondering about, is how long will a mix of 50/50 waste motor oil/diesel last. motor oil should
last virtually forever, and mixed maybe the resultant stock would have a very long shelf life too?

bob g

[thewayne]

Thanks Bob,

I'll take note of your suggestions and maybe it's time to burn it up just to be on the safe side then ... start over
with a fresh batch.

Wayne

[LincTex]

The old red diesel will last for at least 10 years easily if kept indoors, in tight sealed drums. No need to drain condensation from a sealed drum. I wonder how the new ultra low stuff lasts - it seems too "dry" and not "oily" enough.  I suppose mixing oil with it wouldn't hurt a thing. I run 20% WMO mixed in my Cummins diesel in my Ford F-250.

[12gauge]

thewayne,
I was given the contents of an abandoned underground heating fuel tank that was 20 or 30 years old.  It was dark amber color but smelled like diesel so I'm using it in my 6-1 and it seems to like it.
RH

[thewayne]

Wow,

Now that's the kind of thing I was hoping to hear. Not that I want to leave it
for 20 years but ... you know what I mean.

Thanks

Wayne

[cognos]

There is no "shelf life" specification for diesel fuel - but it is recommended to be sold within 6 weeks of having been delivered to a station/terminal. Prior to that, it could have been in storage at the refinery for the same amount of time - but that would not be an ideal situation, as it is expensive to store fuels (as opposed to selling them as quickly as they are made.) It's stored at the refinery at around 100° F in a vented tank, constantly circulated. At the station, 65° is recommended.

The things that degrade diesel are exposure to oxygen, water, and side reactions that occur in the fuel over time.

Exposure to air brings with it oxygen and other airborne contaminants. Oxygen causes components in the fuel to oxidize, producing gums, varnishes, acids, long-chain hydrocarbons like ashphaltines, etc...
Contaminants in the air introduce organic and inorganic products like algae, bacteria, pollen, dust, etc...

One of the first things to fail in a fuel is the dye additive, resulting in off-colour fuel. This is done on purpose, so one can tell if the fuel is "old"  - but that does not necessarily mean it is "bad..."

Bacteria can grow in diesel.
Algae can grow in diesel.
Dirt and dust are simple inorganic contaminants that can cause filtration/flow problems, etc..

There are additives in diesel that can stop or limit the growth of organics in the fuel, but only for a limited time. One can - and should - buy additives designed for long-term storage use.

Water in the fuel can be introduced by exposure to air in a non-sealed container, due to condensation. Water can aid in the growth of agaes and bacteria, and foster the creation of acidic products. It can also create severe corrosion problems in metallic storage containers at the interface between the water layer and the fuel layer.

Additives for long-term storage use contain an oxygen scavenger and a pH buffer.

So - use an after-market additive, keep your fuel cool and out of the light, and store it in an air-tight non-reactive container with the minimum headspace, and that should keep it as good as can be. For how long, it's impossible to say, but several years appears to be possible, as has been stated here.

[Horsepoor]

I was looking for an appropriate tread to post my most recent experience and this thread is close.

I burn 8 year old waste jet fuel in my listeroids. Some fuel is newer but to oldest is from 2005. Once a year, add PRI-D (525 gallon dose) wait a few days, then "polish" the 550 gallon fuel tank with a centrifuge to remove water and filter the fuel during the process. Over the years, this works well but I am down to a couple of hundred gallons after running a couple of thousand gallons over the last 8 years.

To current events: I really screwed up over the weekend. While preforming a load test on some recent modifications, I loaded up my GTC 20/2 (down rated to 850 rpm) to about 35A (about 75% maximum capacity), topped of the tank with several gallons of fuel, and took a quick video clip. What I didn't know, was the diesel container had several gallons of water apparently from a loose fuel container cap. About 5 minutes after all this water entered the fuel injectors, the engine stalled and shut down over a period of about 60 seconds. What a mess, this wasn't fuel mixed with water; it was more like water mixed with a little fuel. I was fearful all this water had hydro locked or blown the engine.  

After purging the water and priming the fuel system, I was amazed to find the engine ran perfectly. Listeroids are pretty much idiot proof, I am VERY pleased. I can't over emphasis the high concentration of water sucked into the engine. I took a sample from the fuel filter, placed it on flammable paper but couldn't get it to burn no matter what I did. For me, this again validates the benefit of running such primitive technology, it's really hard to seriously screw one of these engines up and they are very forgiving.    

[Tom Reed]

+1 on the Pri-D the results with Pri-G have been outstanding too.

How did you get your jet A?

[mike90045]

Does Jet A have enough of the lubricity needed for diesel pumps and injectors ?

[Horsepoor]

Cujet (Chris) is the director of aviation for a billionaire. His employer owns many aircraft. From time to time, service must be preformed which requires the removal of all fuel. Seven years ago I asked him a very stupid question. When the Gulfstream 5 has to have the last 4 or 5 hundred gallons of fuel pumped out for service: why not pump the fuel back into the aircraft when finished? His reply was something like, are you suggesting I risk the lives of everyone on board by pumping a couple of thousand dollars worth of questionable fuel into the 49 million dollar aircraft so it can flame out over the middle of the Atlantic Ocean killing everyone on board? I guess a couple of thousand dollars in fuel compared to 49 million is only a fraction of a penny on a dollar. So from time to time, I get some waste jet fuel, filter, and run through a centrifuge to produce listeroid fuel.

As for lubrication, we use an additive called Opti-Lube XPD. This stuff works great.

Very interesting study on disel fuel lubrication additives, search dwn to the results section.

http://www.dieselplace.com/forum/showthread.php?t=177728

[mike90045]

I think all that goes bad in diesel, is when water is present and bio-slime grows at the boundary layer.