Freezing diesel

[dave50]

In winters gone by many years ago, you always used to hear about diesel fuel freezing in fuel pipes during freezing weather, especially in trucks. You never hear about it nowadays. has the problem been solved and if so, how?

[DTCwordfan]

Diesel fuel is now refined so that its low temperature properties are apt for the geography and time/temperature.

Unseasonable cold snaps can catch refinersout potentially, such as tonight/tomorrow - this is when the temperature drops below the cloud point of the fuel cause operating difficulties due to wax dropping out.
Therefore in refining terms, the cloud point can normally only be lowered by the addition of a product with a lower wax content e.g. Heating Oil and similar products - and that's what they do if the cold snap is prolonged.

However, they can manage shortterm issues by using additives at the loading rack, called cold flow improvers.

This way theylower the temperature at which the wax crystals block filters and the temperature at which the diesel freezes (that's known as "Pour Point).

These additives work by changing the size and shape of the wax crystals, making them much smaller by their chemistry action.

Hope this helps you.

[Hopkirk]

The fun has been spoiled - no more watching truck drivers lighting fires under their fuel tanks.

[TWR]

We used to use Paraffin Dave, although you could have got done for it the derv never froze, at that time in the 70s a few of our HGVs froze up even though the firm paid at that time, £5 a gallon for this non freeze additive that froze up.

[sddsddean]

When I used to run my artic to Austria, I used to put a gallon of petrol in each tank and never had a problem, though technically totally illegal!

[SpikeyBush]

sddsddean my Dad who had one of the first Astra diesels as a company car in 1982 tended to put a drop of petrol in at each winter fill-up for the same reason, but that was when diesel wasn't as refined as it is now and there'd be things floating around in it.

Glowplugs that have seen better days are now much more of a problem than diesel going gloopy.

[JonnyBoy12]

Whilst we are on the subject of diesel I have a few questions about this very versatile fuel. I hope you will be able to answer them.

1 Is it true that you can drop lighted matches into a bucket of this fuel and it will put them out?

2 Can you use biodiesel in place of normal diesel in a normal car?

3 Can this fuel cause motorcyclists to skid on it if they run over it?

4 Is this sometimes called "fuel oil" instead?

[DTCwordfan]

Johnny

1 - yes
2 - Define Biofuel.....if fat derived esters, up to 30% or you risk smelling like a fish and chip shop.
3 - any liquid hydrocarbon risks a spill, lub being the worse...with fueloil (though what would fuel oil be doing on a road)
4 - Fuel Oil is something else all together, full of very long complex hydrocarbon chains (and from which lubricants are sometimes extracted) - huge boilers such as in ships and power stations use it and to ignite it, they actually burn diesel to start with to heat the boilers. Also, diesel is less polluting in ports and near to shore, though there has been a lot done to reduce things like sulphur content (in the trade you will find LSFO and HSFO with corresponding price differentials.)

[DTCwordfan]

sorry 2 if up to 30% fat esters, diesel is ok - above that, it depends on the technique in refining the fats used and the blending.....

[EDDIE51]

JonnyBoy12, the answers to your questions are 'Yes' to all of them !
.
There are or at least there were 2 types of Diesel fuel, Summer and Winter Diesel. Winter diesel has more 'anti waxing' additives than summer diesel.
I used to work in a laboratory where we tested the 'wax point' of diesel fuel.

[DTCwordfan]

Fuel oil is not diesel....big difference in density though I would accept there is a gradation in middle distillates, Eddie.

[EDDIE51]

Been googling 'Yes' there still is Winter and Summer diesel , the change over point is 15th October in the UK . Some discusion of the pros and cons of winter v summer diesel here
http://www.motorhomef...om/ftopic-9245-0.html

[DTCwordfan]

varies by country and refining versus blending policy by the OilCos - winter diesel is all about "killing" the waxes in the diesel that "build up" and clog the diesel (without getting too techie about cold pour points etc

[sddsddean]

Also, technically speaking regarding Q1, you could drop a lit match into a bucket of petrol and the match would go out. Petrol is not flammable, but it is highly volatile. This means it evaporates very easily and it is the vapour that is highly flammable. If you could get the match through the vapour into the bucket of petrol, nothing would happen! This is why an empty tanker is in fact far more hazardous than a full one.

[EDDIE51]

sddsddean I GARANTEE that if you tried dropping a lit match into a bucket of petrol you would have a 'fireball' the match would light the vapour before it hit the liquid . DO NOT mention such an idea even as a joke , there are people stupid enough to try it ! remember the man who poured petrol on to a bonfire on Nov 5th to relight it ! 85% burns

[sddsddean]

Its not a joke Eddie. I said 'technically' you could do it if you could get the match through the vapour to the petrol. If people are that thick to try it, it will make no odds if you or I tell them not to.