Disposing of old diesel and petrol stored in plastic cans.

The usual suggestion is to dilute it in a car's tank before filling up with fresh fuel, that way any stale fuel is diluted with non-stale fuel. Might be less good if the can has been out in the rain and full of water. Probably worth filtering to ensure there are no bits in it.

Not so much help if nobody you know has a diesel vehicle. Perhaps it could be mixed with heating oil?

(see also the suggestion of getting a diesel heater for your workshop...)

Theo

Diesel isn't the issue as we have two diesel vehicles. I am just a little reluctant to risk polluting the fresh diesel in the tanks.

Petrol is the issue as all we have is a little Honda generator which would take (a noisy) forever to get through 5 litres.

Cheers

Dave R

Just use it, or find someone who will 'just use it'. It may not be in the "something of youth" but it will still be fuel. Most engines, especially (for example) rather basic garden/agricultural ones will work OK with old fuel.

But start them on fresh fuel first if they haven’t been used for awhile, a chap nearby could be heard this week adding to the seasonal chorus of curses and cusses as he attempted to start his mower . Quickly gleaned he just knocked the grass off after the last cut last year and parked it in the shed. And the fuel in the tank was last years,in fact it was over a year old because he bought it last spring and because of the dry summer the grass hardly needed cutting so he never got through the can. His son came around and drained the old fuel and cleaned the carb added fresh petrol and it started fine.

GH

Old diesle is great for staring bonfires. Mix 1 part of old petrol to 10 new petrol and put on lawnmower or car

Hmm, no problem with diesel but petrol does go off and lose its more volatile fractions. I’ve known small engines that have been a bastard to start until swapping to fresh fuel.

That said, 5L in a car tank full of fuel probably won’t have that deleterious effect. Split it between two tankfuls if one is concerned.

Tim

Agreed

Exactly. Cant be worse then ethanol on the petrol

Yes, me too - a long time ago when I ought to have known better. I knew it would be "interesting" so put petrol in a plastic bag and threw it onto the bonfire from a reasonable distance (I thought) away. I was wearing shorts and instantly lost the hair from my legs (nowhere else, I'm glad to say) in the resulting WHUMMPP(!) I can't begin to imagine what it's like when a fuel depot gets bombed.

A fuel depot would likely be oxygen starved at the epicenter. You would have to do something to "augment" the situation. It would still burn for a protracted period of time. You need an aerosol, a vapour, for real fun. It needs surface area and lots and lots of oxygen (or an oxidizer).

For smaller rural fuel tanks (at depots out of town), they usually have a moat around them, to catch leaks. Whereas for very large tanks at a tank farm, I don't recollect seeing moats there, as they would likely be no match for a structural failure. Tanks have never struck me as "looking like they were over-engineered". Considering the mass inside them, they look pretty flimsy.

And a question would be, why are they built above grade ? Sure, if they were below grade, you'd never detect a leak. But on balance, having ground or something else around the outside, may reduce the chances of major rupture.

And the fuel tanks should have an inert gas overfill. That way, if your tank is half full, any "blast" will be denied "legs" via oxygen over top of the liquid. Nitrogen is a good cheap material for the purpose.

When crude oil is stored at the tank farm, that's pretty dangerous. When it is sitting there, if you were up top looking at it, bubbles of gas rise to the top and burst. Any void above the top of the liquid, is chock full of "lights". Which could include methane or ethane or H2S. A pipe off the top, can be fitted to lead to the flare stack and that material can be burned off. There isn't usually an attempt to collect and distill that.

Some tanks at chemical plants, have active cooling systems. I'm not aware of tank farms resorting to temperature control.

Paul

Large fuel tanks usually have a floating roof which moves up and down with the top of the fuel so there is no void. John

Do they not always have a bund? Thought that was mandated, but probably wrong.

That is I think mandatory for domestic or business sized tanks. AS far as depots go I really couldn't say (thinking of Flitwick...)

Like the old 'Gasometers"?

It caused no end of problems when I put 3 year old fuel in my car when I ran out of petrol, but the contents of a 5L container in a 50L fillup causes no problems when I dispose of my old generator fuel. I wouln't risk more than

I think that is true. My garden lawnmower was out for a couple of years during house rebuild and simply wouldn't start till I topped it up with fresh stuff.

When I started a summer job between A levels and university, about 45 years ago, I was given fire safety training like everyone who started work there. It was a hot sunny day in summer. We were all led to a grassy area where there were two flat metal trays about a metres square and about 1 cm high. One had petrol in it. The other had diesel. The lecturer lit an oily rag on the end of a long metal pole, and when he brought it to within about 50 cm of the petrol tray, the whole lot burst into flames. Very impressive.

Then he tried the same thing with the diesel. Even with the burning rag right on top of the surface, nothing happened. And as soon as he dipped the rag into the liquid, the flame went out. He might as well have been trying to set fire to water. He tried agitating the surface of the liquid with a pole his other hand while applying the burning rag, and there were a few half-hearted flames that went out almost immediately. The only way he managed to get a slightly better fire was (paradoxically) to aim a CO2 extinguisher at the surface: the blast of CO2 was enough to break the fuel into small droplets which burned fiercely, but the CO2 put them out or else the droplets did not get hot enough to ignite the body of the fuel. Of course, blowing oxygen at it would have been very different ;-) But he said that if you are trying to put a fuel fire out and a CO2 extinguisher is all you have, aim it above the surface of the fuel and let it create a suffocating blanket of gas, rather than aiming the jet at the fuel itself in case you create droplets.

He did eventually manage to ignite the diesel by setting fire to a strip of magnesium and bringing that in contact with the surface: Mg burns a lot hotter, vaporising the fuel enough to start a self-sustaining fire. And the diesel burned with thick black smoke and dirty orange flames, and warped the tin tray, whereas the petrol tray had not got as hot because the fuel burned away more quickly.

Moral: a diesel fire is worse than a petrol one, but only if the fuel manages to ignite.

He also demonstrated what happens if you tip water onto a fuel fire: the water turns explosively to steam which blows burning fuel everywhere, hence the advice to smother a chip pan fire (or any other sort of burning-liquid fire) rather than putting water on it. He got a small chip pan of cooking fat and demonstrated the right and wrong way. A tea towel dipped in water and then *wrung out so it is not dripping* worked wonders (we all tried it), remembering to fold the tea towel back over our knuckles to protect them from the heat as we were laying the towel over - and lay it starting at the

NY snipped-for-privacy@privacy.invalid wrote:

The professionals equipped with the right PPE do sometimes do it differently, I was in a pub I once used as a local when the young girl on duty dashed out of the nominally closed kitchen as she had put a small portable deep fat fryer on to do a a bowl of chips for a couple of regulars, the thermostats must have failed on and flames were beginning to lick out of it .Normally there are two in the circuit on commercial ones to guard against such failure but this may have been a large domestic one. First thing was to Ring 999 and ask the few customers to leave the building while a couple of us carefully entered the kitchen and deployed a fire blanket and unplugged the electric supply. As it happened the kitchen was adjacent to the beer store which I knew quite well and the pub had a nitrogen generation system and a quantity stored so using some convenient pipe work I blanketed the fryer with N2, only gently wafting the pipe over the area not jetting it enough to disturb the oil under the blanket and the flames died down. Fire Brigade soon arrived and assessed the situation and one burly fireman wearing some protective PPE picked the fryer up carried it a door that lead to a garden and put it on the ground where after he stepped well back his colleagues hit it with a water jet. The oil was hot enough to reignite once it got some air and the effect (it was late evening in November) was quite spectacular especially as it largely landed on a blackberry bush which was the only casualty but only lasted about 30 seconds when the cooling effect of the water now being delivered as a fine mist won.

This was forty odd years ago so likely they would not do it like that now, not least because the fire crew would likely have lightly built females onboard and burly males cannot be seen to be better in some circumstances.

GH

Does diesil go 'off' ? I don't think so. Tim W