I’m posting this very long thread as I hope it may explain a few things that I think are essential to understand about the petro diesel that we will now be getting in Australia and how it is very similar in many ways to biodiesel in terms of vehicle compatibility issues. This is useful to know if you are discussing biodiesel with your manufacturer or dealer, or if you would just like to understand for yourself.

First of all, I’ll preface this by saying that biodiesel has no sulphur and is in many ways already far superior to the highly expensive and complex processes that goes into trying to remove the sulphur from distillate (the mineral diesel that people are used to buying, which is really called “distillate”, not “diesel” as it is constantly branded). I’m only posting this thread as I think that most people who are interested in biodiesel need to be aware of “Low Sulphur Diesel” (LSD) and “Ultra Low Sulphur Diesel” (ULSD).

Why is sulphur so bad?
Sulphur in fuels is nasty when it is burned. Not only does it come out as toxic emissions, causing acid rain and other health hazards, but it also interferers with the ability of a catalytic converter to remove other bad stuff in the exhaust emissions. The catalytic converter in a modern engine sits in the exhaust pipe and helps to get rid of the yucky stuff that is not fully burned. Sulphur can choke this catalytic converter up and prevent it from doing its job. This is why many of the older diesel engines do not have the ability to clean their emissions very well – they were designed for a fuel with a high sulphur content.

Why is sulphur so good?
Lubrication. In the olden days, before everyone realised how horribly toxic petro fuels were and woke up to biodiesel, the pre-LSD fuel did a reasonably good job of lubrication. Diesel engines require a certain amount of “lubricity” from their fuel to keep things running smoothly.

What happens when the sulphur is removed?
To remove the sulphur firstly requires political pressure. The major fuel suppliers will market themselves as the saviours of the planet because they will fall into line with government regulations to clean up their product. In actual fact, removing the sulphur from the fuel is a difficult and costly process for them that requires extra refining. The process of removing the sulphur is called “sweetening”. Most commonly, this involves using hydrogen gas to change the sulphur into hydrogen sulphide (H2S), which is also called “hydrofining”. The H2S is then removed from the distillate for further processing. The process of removing the sulphur also reduces the lubricity of the fuel.

How does this effect engines?
Not only does the lubricity drop, requiring additional additives to the fuel to prevent engine problems, but in older engines, problems can be encountered with hoses and seals going brittle and shrinking. The process of removing sulphur from the fuel has now changed the fuel’s properties. If any components in the fuel system are made from natural rubber (also known as "NBR" or "buna-n" or "nitrile" rubber) then they can encounter problems. Seals in injector pumps can shrink, go brittle and leak with LSD or ULSD.

What are the manufacturers doing about this?
Since the mid 90s (dates vary), most manufacturers have been using components made from synthetic materials, such as FKM (also known as Viton). These materials do not suffer from the above problems. As such, most newer cars do not have a problem with LSD/ULSD.

What is the difference between LSD and ULSD?
Simply put, ULSD has 10 times less sulphur than LSD. LSD permits 500 parts per million (ppm) of sulphur. ULSD permits 50ppm. Before this, the maximum sulphur content in distillate was 5000ppm!

So what standards are governments implementing?
There are many different names for different standards in different countries, but I’ll address the ones that are relevant for Australia. In 2002, LSD was introduced to Australia and was mandated to be fully rolled out across the country by Dec 31st 2002. There was some noise made about this, but for most of the average consumers, it went completely unnoticed.
In Europe, the “Euro4” (ISO EN 590) standard meets the same sulphur content as ULSD and was mandated from 2005. Prior to this the “Euro3” standard was the same as LSD and has been mandated since 2000. “Euro5” (proposed for 2008) will be even cleaner.
The “Euro4” standard has now been introduced in Australia from January 2006, which means that any distillate you buy from a service station in Australia will be ULSD. Oddly, very little information is being offered to the consumer about this.


What does this new standard give us?
This has allowed many of the new “clean diesel” vehicles to be imported from Europe. These vehicles will be able to use cleaner exhaust catalysing technologies, as the sulphur problem no longer exists in the fuel. Vehicle manufacturers can now be sure that you will be putting ULSD into their vehicles, so they can be sure that the more advanced methods of removing emission pollutants (like catalytic converters) will not be poisoned by the sulphur content. This way, everyone knows that your emissions will be less and everyone is happy. This is why this year we will see far more diesel vehicles being imported into Australia, with manufacturers like Volkswagen bringing out a diesel option across their entire range of vehicles.

Biodiesel as a lubricity additive.
Remember how the removal of the sulphur caused a lack of lubricity, requiring additives? Guess what the best additive for lubricity is? Biodiesel. Due to biodiesel’s superior lubricity properties, the tiniest amount (like 2%) can be enough to restore the lubricity of ULSD. In France, all ULSD is mandated to contain 5% biodiesel, or another way of putting it is that all French diesel vehicles run on B5. Many of the major fuel companies in Australia are already using biodiesel as an additive to improve lubricity. Australian regulations state that mixes of B5 and under do not require any labelling or info to the consumer, so chances are that you are already driving with a small blend of biodiesel.

What effect will biodiesel have on my engine?
Well, at such a small blend, practically nothing. However, remember we talked about how the removal of sulphur caused nitrile rubber components problems with shrinkage? Biodiesel has the opposite effect – it can make nitrile rubber swell. There have been cases where problems caused by LSD have been solved by biodiesel for this reason. However, too much swelling or shrinking is a bad thing, causing leaks or blockages. The amount of swelling caused by biodiesel varies on the components present and can happen over months and years, not immediately, Also, the lesser the blend of biodiesel, the lesser the effect. B100 can soften hoses and swell seals over only a few months. In a newer vehicle with synthetic components, there is no problem at all.

So what do ULSD and biodiesel have in common?
Well, they are both more environmentally friendly than the old “dirty diesel” and they can both cause problems with seals and hoses in older vehicles. Most importantly modern vehicles with synthetic hoses and seals can run quite happily on both. If a vehicle is compatible for ULSD, then it is also compatible for biodiesel.

What are the differences between biodiesel and ULSD?
ULSD is low sulphur. Biodiesel is NO sulphur.
ULSD has far less harmful emissions that less refined distillate. Biodiesel in it’s natural form has far less emissions than ULSD.
There seems to be no responsibility taken by either the manufacturers, or the major fuel companies to warn consumers of the risks to older vehicles of ULSD in Australia. If any parts fail, it will clearly be the consumer who has to bear the brunt of repair and replacement.
With biodiesel, the suppliers are making an effort to educate people of the issues that this fuel can cause to older vehicles.
New vehicle warranties are not affected by ULSD, as manufacturers know that they now use synthetic components that will not be subject to shrinkage or swelling. Curiously, most manufacturers in Australia have no position of biodiesel (or a negative position out of ignorance), when the only issues potentially caused by biodiesel are the same as for ULSD and are already solved with the same synthetic components!

What implications does this have with new vehicle warranties on biodiesel?
If you ask a manufacturer to confirm compatibility of their vehicle with biodiesel, they’ll more than likely go into an ignorant panic spin and tell you that they will not warrant the use of biodiesel, possibly because they say that there is no standard (which is not true), or because they have not yet done enough testing on biodiesel, which is closer to the truth. You will be better off asking them if they can confirm compatibility with ULSD instead. At least they will know about that one. They will of course tell you that there will not be any problem, as they have had enough time to ensure their new vehicles meet “Euro4” spec. As we have learned above, if the car has synthetic bits, you will not have a problem.
Biodiesel bought from a reputable supplier, meeting the ASTM spec will not cause any problems with your engine. The photos of soaped up pumps and gummed up pistons that your dealer might have seen Bosch produce are caused by biodiesel that does not meet this spec and is just propaganda. One day dealers and manufacturers will all get to understand this better, but in the mean time, we will have to educate ourselves and not rely on their ignorant opinions. Hopefully if enough of us ask and insist, they will come around eventually.

Here is a good example of a manufacturer who is not afraid of ULSD, because they know their parts are synthetic. I bet if you were to ask them about biodiesel, they’d probably give a different answer purely out of ignorance.

Lucky you know better!

__________________
Robert.
Site Admin.

Hi Robert,

Many thanks for posting this article, although I have started to understand some these problematic areas of late, it has had to be gleaned from long articles ,sometimes arduous to say the least.
I enjoyed this posting . It helped me towards a clearer understanding, more importantly, it will help me to focus and be able to pose clearer questions to my need for further information.
Good and clear article. Many (like me) do not have the time or understanding of some of these issues to be able to concisely deal with one of our favorite subjects Thank you.

Dillyman

Robert,

thanks for this posting. I think it pretty much summs up all the hundreds of pages of info I have so far collected.

The main important factor for use of biodiesel in newer enginenes is really the quality of fuel in manufacture, transport and storage.

If the fuel is manufactured to standard and kept in clean well maintained tanks there should be no problem.

Andreas

Good effort Robert,

i see you are on a roll again with the division of your time between your 'real' job and your 'hobby'

thanks for the info

darren

Thanks Robert for your effort , very good reading . Interesting to note that biodiesel can cause rubber to swell . I can recall when I was washing parts in kerosene how if they were rubber they used to swell almost to double their size ,especially if they were brake parts , we soon changed to using just water for brake parts . I can also recall in my time on the cattle stations with lister & southern cross stationary engines , in their handbook they used to give you a "recipe" of mixing kerosene and oil to run their products if no diesel was available .

Cheers

Peter

Well written, but I am confused, I have read that it is not the sulphur which provides the fuel lubrocity. In fact, it is Sulphur build-up in the engine oil which minimises the engine oil's lubricating characteristics. In fact, if there were any test data on engine oil, it would proabably be discovered that oil change intervals (using B50 for instance) could probably be extended by 50-100% based solely on the absence of S.

Regardless, I understand it is the process by which the sulphur is removed that inhibits Ultra Low Sulphur Diesel's lubricating characteristics. The "Hydrodesulphurisation" affects the lubricating characteristics, not the S itself.

Now, I do not remember where I read this, but it wasn't a comic book, and I would like to be correct. Is there any trivia person out there that actually knows the answer?

Emission reports re: biodiesel & ULSD blends are inconsistent, and vary in their findings. The New Jersey report states the findings regarding NOX emissions and Energy Content are unquantifiable, and require additional research. Seems there is a link between emissions and duty-cycle, type of engine, and condition of the engine.

Currently, there does not seem to be much interest in developing new research into BioD/ULSD blend data, but it is NOT the same as the LSD data. Perhaps, someone will take the intiative and actually study this issue, as it appears that there could be a significant impact on the emission data currently circulated.
ML

__________________
Morris Lyda
[URL=http://www.thebiodieselstation.com]
The Biodiesel Station

Good point - I will edit the post to say that the removal process causes the low lubricity, not the lack of sulphur itself.
I'd love to see a study of ULSD/biodiesel blends done in Australia. In fact, it is very hard to find any really good Australian test data on biodiesel emissions.
Anyone have an exhaust gas analyser lying around?

__________________
Robert.
Site Admin.

We have just bought some american F250 fords designed to run on Ultra low sulphur diesel. I cannot get this in zambia and am now looking at posssibly using b100. Apart from the rubber hoses and gaskets which should be ok being a 2008 model, is there any problem with the catalytic converter or any other part of the engine experiencing difficulties?

I have just got my first tankful of b100 and it runs perfect. I cannot tell the difference. The manufacturer of the biodiesel could not give me a 100 % assurance that there will be no problems. How can I tell if there is going to be trouble and what signs do I look out for?

Hi Zambio,
You can get 500ppm Diesel from the BP service station on Kafue Road (on your left if you are driving north towards the city centre) This is the only garage that is currently selling LSD.