~Biodiesel The "Least Stable" Among Fuels

The "least stable sample is the B20 biodiesel even [though] it contains a substantial amount of sulfur," the researchers found. "We conclude that the instability of B20 biodiesel blend with off-highway diesel fuel comes from an acid-catalyzed hydrolysis of the ester components from the biodiesel."

Nor are problems likely to arise solely from the deliberate mixing of used oil with fuel, as with the Cummins "Centinel" recycling system. While that system results in about a 3,000-ppm dose of lube oil in fuel, the newer high-pressure fuel injection systems also result in about 1,000-ppm of lube in fuel, Stehouwer explains.

A separate test of cetane improver in 20% biodiesel blend (B20) found even worse instability problems, the researchers found. This is of special concern because modern high-pressure injection systems circulate a lot of fuel through hot injectors (as a heat sink) for return to storage tank.

That's why engine makers are pressing for a tough thermal stability limit in American Society for Testing & Materials (ASTM) D975 diesel fuel standard, as well as similarly tough thermal stability limits for biodiesel blends.

With diesel fuel, careful fuel blending and proper additization could avoid stability problems, Stehouwer points out. Otherwise, thermally-unstable fuels could form gums that could plug filters and cause injectors to stick, resulting in costly repairs, he said.

COPYRIGHT 2003 PBI Media, LLC
COPYRIGHT 2004 Gale Group



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[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

screw the press.. screw the scientest that say its crap.. if it works run it.. if its clean run it.. they must of been paid by big oil ..

is crap. Why waste your money? Go B99/100.

Jay.

__________________
On the road, currently:
'83 300D (German spec.) 168k mi. - - Wolfgang (tucked snugly away for the winter!)
'87 300D 375k mi. - finally went over to "The Dark Side"
'87 300TD 225k mi.
Cannondale 66cm CAAD5 w/Campy/Jamis Aurora
Hujsak Custom Fixie/Landshark Track Shark Custom/Ahearne Custom 29'er

Well, as long as you have a well thought out, factual argument it must be OK.

Personally, I'll wait a couple of years and see how the whole thing works out. Bio-diesel is either a great idea, or the folks that rebuild IPs for a living will get real busy. We'll see what happens.

Guess what, we are already seeing what happens, people are putting hundreds of thousands of miles on biodiesel (mostly truckers who have been using B20 for many years). Biodiesel is not as new as you think.

Stability is a concern, but there are ways around it. There is argument in the field about the necessity to leave tocopherol (vitamin E) in the feedstock during processing, which causes it to remain in the final biodiesel, or to remove it for sale by itself. Tocopherol should be left in, or even ADDED to biodiesel, because it prevents oxidation, and increases thermal stability. I agree that there should be an ASTM standard for thermal stability, but I'm confident that biodiesel producers can meet that standard.

peace,
sam

__________________
"That f***in' biodiesel is makin' me hungry."

1982 300TD Astral Silver w/ 250k (BIO BNZ)
2001 Aprilia SR50 Corsa Red w/ 5.5k (>100 MPG)

i bought my 300D for biodiesel and by gum im going to run it




as soon as i get fuel filters

And by gum is what your gonna get !



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__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

I understand there a lots of people using it successfully, I'm just not ready to jump on the bandwagon. Personally, I do not believe the technology is mature enough yet. Hopefully, these issues will be worked out and BD will become more widely available. I wouldn't be surprised to see BD use become mainstream in 3-5 years. I can wait.

While the argument is very pertinant to people with newer cars running these fuels, I think the older IDI engines with purely mechanical injection are really not going to see any problems.

I've seem/felt every part of my fuel system in my hands (even the stuff inside the IP!) and after running varying blends of biodeisel (home made...nothing fancy at all) I see no problems.

The injection shop has tested my injectors, etc. and nothing abnormal has crept up.

In the long term? Perhaps a problem will show but honestly is gumming of something serious enough that it will physically damage the old clunky stuff?

Unlikely...

Newer cars? Yes I think there could be a problem.

Just wait and see...but don't worry about protecting your 1970's-1980's "delicate instruments"...they really aren't all that delicate

Just means there's more for me. I've been running B100 off and on (mostly on) for 2 years now. And now it costs me $0.70 per gallon to make. Go ahead, run the stinky stuff.

__________________
'83 240D with 617.952 and 2.88
'01 VW Beetle TDI
'05 Jeep Liberty CRD
'89 Toyota 4x4, needs 2L-T
'78 280Z with L28ET - 12.86@110
Oil Burner Kartel #35

http://i16.photobucket.com/albums/b1...oD/bioclip.jpg

Yeah....what he said! HUH??
I bought into the whole b100 and the wvo thing hook line and sinker and that's why I got froggy and jumped on my 800$ 300SD, now I kinda like running on Diesel but at $2.39/gal I'm getting over the novelty and back to the automotive wet dream that is VEGGIEPOWER! Seriously though I can't really see the problem with ingesting veggie esters with their higher cetane ratings, greater lubricity and cleaning properties et al...with very little to lose in my case why not, yet it is worrysome that while the internet is chock full of success stories it is equally bereft of dismal failure. Last weekend I burned a liter of homebrewed/washed b100 from a jar under the hood and into the IP and she never complained....smelled different but ok. Now I have to see if all that filtered wvo from Happy Noodle will burn with only 180* of heat at the IP...then I'll be happy! I'll sing a different tune if the IP goes tits-up and sure as hell I would not play this game with anything but an old 5 banger like this but it's such a fun idea, rolling the dice to find out if I can burn garbage while toolin down the road in style...well, I got triple A and a cell phone so what the hell.

__________________
1983 300SD... 269,000 miles, nearly 2,500 on my B-100, Faded Grey, Ugly in an elegant sort of way...Duh-Benz


If any of this has been a blasphemy to you, then good, because it's been a blast for me to...A.Whitney Brown

i'm withya old300d. we been making our own b100 since march and have run it in 5 mid 80 cars with no problem and better exhaust smell ansd emissions. when we bought red last jan we started a diest of b20 and she enjoyed it a lot more than the crappy 40c that mobil, shell, citgo flying j all sell. if others wnat to run the stinky that makes more for me when i have to purchase it. for now i am combining 5 gal of b100 homebrew with a fill up of bp premium 50c and the cars like it okay. not as quiet and clean smelling as b100 but still effective.

__________________
currently
[1981 300 td tdidi 165500 dark brown/palamino-Brownie-mine-3k miles of ownership
1983 240d 162+++ Anthricite grey w/ henna red interior and hella lights-wifes car-Red

the above two cars are for sale
and can be seen on the cars for sale thread here. pix also available.


240d-144+ Manilla Yellow w/ palmino interior-greasecar kit-Blondie-the college kids car

23" gt 21 speed still on original tires-still got the nubs
21" khs tandem

Remember too, that while WVO and SVO and Biodiesel all seem pretty similar on the surface, they are very DIFFERENT chemicals, with different combustion properties, different physical properties, different chemical properties, and different rates of success, emissions output, and wear on parts.

WVO can work fine, but don't mistake a success or failure of a WVO project as a success or failure of biodiesel, which has had many years of industry support and testing. Its easy to hear "I heard about a guy who siezed his engine while running WVO" and think that it has something to do with biodiesel, but it really doesn't, the issues are very different for the two processes. (and yes, I've got experience with both systems).

peace,
sam

__________________
"That f***in' biodiesel is makin' me hungry."

1982 300TD Astral Silver w/ 250k (BIO BNZ)
2001 Aprilia SR50 Corsa Red w/ 5.5k (>100 MPG)

I would recommend that anyone participating in this discussion read the entire article from which the information cited in the OP came. It can be found here.

It's not a complete research paper, but rather, a thumbnail sketch of part of a presentation of an SAE research paper.

Interesting article, I'm sure all this will get sorted out eventually. In the mean time, I would still advise caution. I have nothing against running BD and/or VWO, it's just not for me, yet. I just have a funny feeling that in a few years people will be selling used diesels with adds that read, "never run on VWO." Hopefully you guys will prove me wrong.