Thread: Biodiesel and Particulate Filters (DPF)

FB, can you please explain why "I can't post the entire report due to copyright restrictions".
I thought copyright applied to an entire document. Are you using this as an excuse to withhold useful information about findings on dino diesel from us?

I am not wanting to enter this discussion but just give you my imperical results form oil tests I have had done with a new common rail engine, run all its life on B100. There has been absolutely no degradation of the lubrication oil nor any deposits of fuel found. Wear was at the low end of normal which I expected.

I also tested my older direct injection turbo motor and it too showed reduced wear from the use of biodiesel in all wear metals. Again no oil dilution was present and soot was reduced. It made a few doubters into almost converts amongst a group of similar vehicle owners!

I cannot comment on DPF use with biodiesel but I would be very wary of any report stating that the use of biodiesel causes rings to stick. Oil problems will result if you abuse the oil, so don't. 1000 hours at 100 km / hr gives us 100,000 km's, even at an average of 50km.hr its 50,000 kmboth are a bit high for my liking.

Now I do not know about you but I would not for one use my engine oil that long in a pink fit without constant testing and monitoring.

The only thing I would see the biodiesel in the oil doing is oxidising under temp and polymerising, not breaking down into anything nasty. In fact its one of either petrol or diesel that actually forms sulphuric acid in some cases but in most cases the mineral fuel will make the oil acidic. Not biodiesel.

There is a lot of obsfucation / misleading info out there.
My 2 cents,
Matt

So the next question appears to be

Who is F-B and what is his connection to the motor fuel industry?
I confess I had not read this thread until today.

Being a very cynical sort of fellow, I am always concerned about "Experts" who suddenly show up posting lots of information that is anti-biodiesel and which seems to not agree with what mopst people have experienced and who post to no other thread.

Tilly

I dont know who FB is or isn't, same as you. My thoughts as to his "expert" nature however.....

The biodiesel study done on refrigerated transport units in europe, which is only part of the study. If the ambient temperature was cold, (say only a few degrees) it may be the temperature that" biodiesel viscosity becomes 50% greater than fossil diesel" The fuel could have been at its gel point, we dont know.
If it was cold, the TRU would not be operating at a great load, (which is noted in the paper) also which would contribute to engine coking, fossil or petrodiesel.

The final paragraph says
"All four of the B100 Biodiesel fueled engines had at least
one stuck top ring at the completion of the 1000 hour
test" (implying the fossil diesel engines were fine?)

THERE WAS ONLY FOUR ENGINES IN THE TEST.
NO ENGINE WAS RUN ON FOSSIL DIESEL.
THIS TEST WAS TO COMPARE LUBRICATING OILS, NOT FOSSIL AND BIO DIESEL.
A FOSSIL FUELED DIESEL MAY HAVE PERFORMED WORSE.

Me shakes head I have little to zero idea of what most of this thread is about, other than to say I am happy to run Bio-diesel in my $50K July 2005 model Holden Rodeo without fear or faviour.

My Uncle is in his mid 60's and he work with the public works as a fitter an turner. I have had many hours of talks with him about bio and diesel engines etc everything from diesel knock to lubrication to flash points and he is also happy to run bio in his diesel with out fear. He has seen the results of Low Sulfur Diesel on engines and anything has to be better than what it does to componets.

He belives that Bio is the best thing for diesel engines based on several things but mainly the lubrication that it provides, but also the fact that it has a higher flash point and in the 3 diesels we have anything to do with including my rodeo it has reduced the diesel knock to something at times which sounds like a normal quiet petrol engine and he loves it.

He can't understand what all the fuss is about other than the petro-chemical companies realise that if they can't stop bio with FUD they will lose a whole market with ease and never be able to regain control.

What causes coking? Sticky rings? Injector problems? etc etc when using only biodiesel and not petrol diesel ?...

Just at a very rough stab (because I am no scientist) but I would guess that poorly converted fuel, soapy fuel, glycerol laden fuel or all of the above.

I just find it difficult to see how pure biodiesel could possibly cause any of the issues described in this thread..... The only thing that I feel could contribute to any of these would be during warm up or until the engine is a full operating temp.

There has been documented problems with a particular Japanese 6 Cylinder Turbo Diesel Engine that the Big End Bearings failed at around the 100,000km mark, but this looks like it was due to nothing other than using API oil in a High Performance Diesel Engine. i.e. If you have anything other than a US built engine you should research what oil you put into the engine... In my engine for example I no longer use Castrol RX Super as it is a API oil designed for sloppy US engines but instead I use Caltex CXJ J=Japan designed for close tolerance HP Diesels. One of the symptoms of using an API standard oil was sticky rings and interestingly after I changed to CXJ the first oil change the oil was rank i.e. stunk disgusting then I starting using oil as it never had before after the third oil change that settled down and then the oil would not discolour much between oil changes. This was all before I started using Biodiesel. Now my oil is just off colour at each 5000km oil change. Soooo what I am saying is that not all engine problems including piston ring issues can be directly attributed to the use of the type/condition of fuel that is used but also what engine oil you run.
My 2cents worth......
BTW I had my bigend bearings replaced at 75,000km's as they had begun to flake. I was told that I would have likely had a rod out the side of the block within 12mths if I had not gotten them checked. Also this BE problem was only with 1989 - 1995? Toyota 1HD-T engines.

I could be wrong here, but to me it sounds like to issues F-B is referring to might be caused by SVO mixed with diesel. I've noticed that in the UK, it is a common misconception that mixing vegetable oil into diesel = biodiesel. I have seen many studies unfairly blame biodiesel when they were really using SVO + distillate, which is a completely different thing and I suspect would cause the results that they mention. Biodiesel would not perform as described.

The definition of biodiesel: biodiesel refers to alkyl esters made from the transesterification of both vegetable oils and/or animal fats.... it's a processed fuel that can be readily used in diesel-engined vehicles, which distinguishes biodiesel from the straight vegetable oils (SVO) or waste vegetable oils (WVO) used as fuels in some modified diesel vehicles.

F-B can you give some information regarding the biodiesel used, what was it made from, was it made to an internationally accepted spec, what blend was it, etc?
Seems that this thread has gone a little off topic now, but what I am most interested in is how biodiesel (I mean REAL biodiesel) can affect particulate filters, when most of the available evidence seems to indicate that biodiesel will help the performance of said filters.
How about we leave the stuck rings and diluted lubricating oils for another thread and discuss why some manufacturers are putting telling us that biodiesel is not suitable for their vehicles because of a DPF? This is what we really need to know and I feel that we have still not got a suitable answer, at least not one that I have yet understood.

Blimey.

I was attempting to offer some enlightenment on DPF usage with biodiesel but admittedly have got a little side-tracked and taken everyone else with me it seems.

Anyway, I'm neither anti-biodiesel nor trying to feed anyone duff info. Far from it in fact and to be honest I resent any such accusations. I'm not an expert on biodiesel and never said so. It can be frustrating for others when a stranger crashes into a discussion group and offers a dissenting opinion. From looking at other threads it seems that the majority of people are looking for a discussion rather than a bio fan club. And consequently I felt inclined to offer some contribution.

The "1000hr" SAE paper is not even meant to be quoted without permission and I hadn't realised that...I was expecting a "fair use" permitted for review purposes or the like. If you want to purchase and read it go to the SAE website and search for Effect of Various Lubricating Oils on Piston Deposits in Biodiesel Fueled Engines by Thomas R. Sem, 2004. I've got access to this via my employer and it'd be a bit daft to so openly ignore a copyright don't you think?

I should point out here that I'm used to dealing with service intervals of 25,000km, so it's not unusual to see an engine running for at least 500hrs without an oil change. We have seen customers that will do 1000hrs before changing oil as their average speed is so low (less than 25km/hr). Oz seems to be following the US with far shorter intervals (but is the lube a lower spec consequently..?).

Regardless of this, I've taken another look at the paper. 1000hrs does seem like a long time. But the test was also run with petro diesel for the same length and no top ring sticking deposition was observed, this list is reported:

Engine Oil and Fuel (% of Piston Diameter with Black, Sticky Deposit in Top Ring Groove)

• Fleet grade mineral oil A and B100 fuel 100%
• Premium mineral oil B and B100 fuel 100%
• Semi-synthetic oil C and B100 fuel 40 to 50%
• Fully synthetic oil D and B100 fuel 40 to 50%
• Fleet grade mineral oil A and petroleum diesel none

The duty cycle of the test was:

• 15 minutes at 2200 rpm and 21hp (which is 62% of rated load at 2200 rpm),
• 44 minutes at 1450 rpm and 10 hp (which is 37% of rated load at 1450 rpm),
• 1 minute shutdown, restart at high speed and repeat.

The oil temp was a moderate 204°F (c. 96°C). I don't perceive the low temps here and the moderatre duty cycle to be excessive for an engine. Fuel temps aren't mentioned but I'd expect them to be close to an in-cell ambient of 30-40 degrees C. There's no mention of the sump volume; it may/may not be sufficently large to permit a 1000hr change cycle. the engine was also naturally aspirated which would have made it a little less strenuous for the oil in comparison to a vehicle engine with a turbo.

So that's one peer-reviewed paper that offers some different facts and opinions about 100% biodiesel. The fuel used was the commercially available soya-based fuel typical of the US; perception is that this has worse properties than the rape seed or palm oil variants. To quote, "The fuel was sourced from West Central Soy in Ralston, Iowa."

Unfortunately this paper, whilst in the public domain, is not free. The abstract is not however (as far as I know);

ABSTRACT

Some customers of Transport Refrigeration Units (TRU’s) powered by 2.1 liter diesel engines in Europe are requesting to run 100% biodiesel fuel in their TRU’s.The purpose of this paper was to find a way for users of 100% biodiesel fuel to maintain reliable diesel engine operation through selection of a better engine lubricant.

Diesel engines that have been run with 100% biodiesel fuel have been found to have deposits inside the engine that are not found when running on fossil petroleum diesel fuel. This paper examines the effect of various engine-lubricating oils on engines running with 100% biodiesel fuel. The comparison of various engine oils was accomplished by evaluating the piston skirt and ring groove deposits when running 4 different engine oils for 1000 hours each on identical.

So what would be the implications be...if you're using a far shorter service interval with a "better" fuel and better lube.....probably nothing! Given that your average speed maybe in the region of 50km/hr a 10,000km service would a max 200hr oil life, 5 times less that the study. I'd have to admit, I'd probably risk it with the 10kkm interval too.

So that was several hundred words of irrelevent monologue. Marvellous.

Anyway, cDPF usage with biodiesel means that large amounts (say about 3% by mass fraction for a B30, for a B100 it will be way higher) of fuel will be churning round with the lube with long service intervals (25,000km). I have seen lab reports that lube laced with biodiesel at these levels oxidises and polymerises far more rapidly than with petro diesel. Shorter service intervals may mitigate this problem, but to what degree? Nobody knows, or isn't saying.

Data for the test fuel (sorry if the formatting's a bit wonky)

APPENDIX
CERTIFICATE OF ANALYSIS FOR THE TEST FUEL

ASTM D6751
LIMITS for
biodiesel
blendstock
FUEL SAMPLE
LOT NUMBER

BD020403

FREE GLYCERINE %

.02 0.00008

TOTAL GLYCERINE %

.24 0.1297

FLASHPOINT, Cº

130 MIN 136.29

WATER & SEDIMENT, % VOLUME

.050 0.01

CARBON RESIDUE %MASS

.05 MAX .0292

SULFATED ASH %MASS

.02 MAX .001

KINEMATIC VISCOSITY Cst, 40ºC

1.9-6.0 4.2138

Total sulfur by UV
fluorescence % mass

.00004

CETANE NUMBER

47 MIN 49.86

CLOUDPOINT Cº

0

COPPER CORROSION

3 MAX 1A

ACID NUMBER mgKOH/gm

.80

.89
PHOSPHOROUS BY ICP% MASS

.001 MAX 0.0007

SOAP IN OIL, PPM

47.2

DISTILLATION AT REDUCED PRESSURE Cº

360 MAX 350

IODINE NUMBER

131

Just a reply FB, firstly thank you for your input we will all be better for it one way or the other.

As for the Fuel Test Spec, the critical things are not there like the percentages of unreacted Mono Di and Triglycerides which will contribute glycerides to the burning process. As HDJ80 pointed out I am also well aware of the oil and bottom end bearings issue and it was the lube oil that caused this, in this case the incorrect oil! I am not aware of the ring deposits but I have a very similar engine and flushed it before going to a synthetic oil first then to a J (Japanese) spec oil for a J diesel. Engine design and particularly pistons, rings and tolerances are one of the bog changes between engines.

Your 1000hr at 25 km/he is 25000km but even that is stretching it, I have a car that has 20,000km changes but will not go over 10,000 without oil testing. It runs 100% biodiesel (how good it is I do not know categorically) and after 33000km = 1000 hrs at approx 36km/hr average speed its fine so far, starts and runs well and no odd things are found in the oil samples tested so far. I will do another one soon for peace of mind but I hesitate to think of taking the head off it to look! The Toyota I have may get that treatment and then I can make a decision either way!

Keep up the effort, all input is for the better.
Matt