Diesel & Sulphur

gunnarsilins

gunnarsilins

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www.eilean.se
This is probably an old issue, but I´ve heard a rumour that due to the lower sulphur content of diesel fuels nowadays, older engines would benefit from having about 0,5% 2-stroke oil mixed with the fuel.

I also get the impression that various bugs in diesel fuel is a more common problem nowadays - could it be linked to the lower sulphur content as well?

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No and no.

The benefit of sulphur in diesel fuel is that it forms boundary lubricant films on very hot components, mainly the exhaust valves. Low sulphur fuels have alternative high-temperature lubricants added to compensate for the reduced sulphur. Adding oil will do nothing because it will have burnt by this stage. A two-stroke oil contains some similar lubricants but you would only be duplicating what has already been done by adding it.

Diesel bugs are sulphur-reducing bacteria. If there was no sulphur there at all there would be no bacteria. The other component that is required is water. I suspect that the reason for more reported cases of the bug is:
1. Lower standards of storage, introducing water to fuel tanks
2. More people talking on these forums.

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yawn yawn

yes we went over this a few months back, sulphur is expensive to get out of diesel fuel, crude oil with hi sulphur is less expensive than lo. profits drive the industry, lo sulphur diesel is being driven by pollution legislation, sulphur in fuels only cause accelerated wear due to combustion by products. no sulphur is highly desireable
s

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Re: No and no.

There are approx 13 different types of bacteria that commonly grow in diesel.

The most common diesel 'bug' that causes all the sticky gloop, does not require sulphur. It will grow quite happily without it.



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Re: What\'s that then?

How about Hydrocarbon Utilising Micro Organisms

BAH HUMBUG!!!!

<hr width=100% size=1>Dom

2003 is going to be a good year for me
 
Re: What\'s that then?

Probably cos there's no such thing. It's down to chemical bonds. Anaerobic bacteria, which include Sulphate reducing bacteria, reduce oxidised sulphur containing compounds. They gain energy from this reduction, and can survive without oxygen.

Aerobic organisms can utilise hydrocarbons in the presence of oxygen, and have no need of any reducing reactions, and are therefore not called hydrocarbon reducing.

If you're interested in knowing more, there is a really good (relatively simple, but probably needs a little understanding of biology and chemistry) explanation of all this at <A target="_blank" HREF=http://www.betterenginesolutions.com/resources/philosophy.htm+sulphur+reducing+bacteria+diesel&hl=en&ie=UTF-8>click here</A>

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Re: What\'s that then?

Your link didn't work, got me into the host site but I couldn't find the bit about diesel bacteria. I did some searches, though, and find that, as you say, there are potentially other bacteria than sulphate reducing ones. Doesn't alter my main point, though. All are introduced by water. Uncontaminated diesel does not develop bacterial infestations.

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Re: No and no. ??

SRB ...... Sulphur Reducing Bacteria is only a part of the Bugs .... There are two distnoct tests run by us and other labs for bugs, depending on whether client wants to know SRB or general.

The problem of bugs is more general than just Sulphur.

But I agree that the more talk about it causes more to find and know about it. You also have the situation that the bug is pretty worldwide - making it difficult for a supplier to secure clean stock. In fact I would say that there is not 'TRUE CLEAN' stock - even straight of the crackers ....

We run Bug testing literally daily and never find clean diesel / gasoil.

The Lubricant for diesel .... Lubricity Additive is a polymer based additive and not quite the same as 2T .... but I would not add any other oils to any diesel - unless you wish to smoke out the neighbours !! It will be worse than useless - possibly only carboning up the engine.

Reduction of Sulphur is an issue that is still leading to a lot of industry chat .....


<hr width=100% size=1>Nigel ...
Bilge Keelers get up further ! I only came - cos they said there was FREE Guinness !
 
BONG !

Sorry but not always true.

Many of the problems emanate from the storage tanks used and having been contaminated and then not cleaned properly.

Also it is not necessary for water to be the carrier, it can be transferred in 'dry' diesel .....

Finally everyone goes on about Diesel and Bugs .... let me throw this one in :

Lub-oil can develop a similar problem, in fact any hydro-carbon in the range of Gasoils and Lub's can develop it - it is just more prevalent in Diesel.

haviong been involved in a ship that had its engine sump swarming with it ... it actually caused the engine sump paint surface to 'slide' down into the sump bottom ..... it was 'orrible !!


<hr width=100% size=1>Nigel ...
Bilge Keelers get up further ! I only came - cos they said there was FREE Guinness !
 
Re: BONG !

I am totally ignorant on this, so I will not disagree with your statements, just ask questions...

If lubrication oil in an engine can get bug infected, will the bugs survive after the engine has been run at full operating temperature, or does the oil get hot enough to kill off everything living?

<hr width=100% size=1>Adventures of the VAT unpaid <A target="_blank" HREF=http://www.xrayted.fsnet.co.uk>Teddy Bear Boat</A>
 
Re: What\'s that then?

Hmm!, It was working last night, cos I checked it, yet today it isn't,aint the internet wonderful

Just in case anyone is sad enough to want to learn more, <A target="_blank" HREF=http://www.betterenginesolutions.com/resources/philosophy.htm>here is the working link</A>

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Re: No and no.

Here in the US, the problem with low sulphur diesel seems to have been leaks in the injection pump due to the rubber O-rings being damaged. The solution was to replace them with nitrile O-rings.
john

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Re: BONG !

Water is present in all petroleum products - in minute or even larger amounts. It is in two forms : Suspended .... normally in ppm, second is free water in larger amounts.

Bacteria can survive in diesel between storage tanks based on its ability to a) find water in either of above forms, b) limited period survive without.

It cannot be said absolutely that it must have water or not .... as it seems that there is mutation already in bug forms. I would leave that to the Micro-Biologists out there to state. BUt I do know from my own lab work - that we are finding it in 'dry' and 'wet' petroleums.

I think the technical aspects are not really necessary here - just to emphasise that free water should be drained off from tanks regularly and kept topped up. Everyone quotes 'with fresh diesel' ....... makes no difference as the bug is there in old and new whatever you do....... cleanliness of the pump station that you get it from .... is again basically irrelevant ..... OK so yes - stagnant old stock allowed to accunmulate condensation etc. will allow the bugs to multiply etc. But very few diesel stations have fuel staying stagnant that long.

There is a well known fuel station in Langstone harbour that many avoid .... they claim that the tanks are dirty and not looked after ....... sorry but wrong assumption .... I know I have been suing their fuel for years and no problem - I only stopped as I found a cheaper supplier !!


<hr width=100% size=1>Nigel ...
Bilge Keelers get up further ! I only came - cos they said there was FREE Guinness !
 
Please it was posted as info.

No idea as tyhe lub oil I saw it in was on a large ships engine which the sump should not be as hot as a boat diesel engine ....

I would asume that its possible. But PLEASE - I put forward the Lub-oil bugs as illustration that all is not so clear on this subject as people think ........ I would advise that No-one start worrying about Lub-oil bugs - it is highly unlikely ..... remember that a ship uses Lub-oil purifiers and all sorts to lengthen the life of the lub ..... its there for years !! On a boat engine you change oil like you do on the car - at least some do !! so why worry !!!

A drop of Biocide in the fuel now and again, drain off the water, clean the filter bowl and away you go. (Sorry to repeat m'self - but I haven't drained my tank etc. for quite a while and don't have a problem - maybe my tanks not good enough for 'em !!!!


<hr width=100% size=1>Nigel ...
Bilge Keelers get up further ! I only came - cos they said there was FREE Guinness !
 
Re: What\'s that then?

Water is nearly always going to be there. Condensation is ever a feature in boats, and tanks aren't anymore resistant to this than other parts of the boat. You'll get enough water condensing in a tank to give the bugs half a chance to grow.

If you keep the tanks topped up, then you may minimise this effect, and rapid turnover of the contents will also help. Or add one of the additives that are supposed to remove the diesel/water interface. Can't comment on how effective these are. All I can say is that if your tank or diesel becomes contaminated, the bugs will grow if conditions are halfway decent

Years of experience in growing the things, identifying them, and being amazed by them, bugs will grow in just about anything.

An example, is if you want to isolate some soil bacteria, you add cyanide to the medium in which you are growing them. I used to have a 1kg tub of Potassium Cyanide under my bench for this purpose. Scared the hell out of my colleagues whenever I was measuring it out, and used to do it late at night eventually. Had to keep all sorts of emergency antidotes in case I inhaled any or otherwise contaminated myself.. the wee bugs just thrived on it.




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