Interesting, what's your source on this?

 

Here is one: http://www.old.international-agrophy...08_22_1_21.pdf

After browsing through that expecting to find lower cetane numbers from bio, I have some observations.
Interesting the Cetane increases more if the "bio" part is more vegetable fats than animal fats. (Unsaturated fats vs saturated) I would have thought because the "bio" part is an edible thing it would spoil and reduce cetane but it increases in cetane the longer it is stored. I've thought of cetane as a measurement of stored energy but that appears to be wrong also, more or less it's just a measurement of flash point. More cetane doesn't equal more power.

Thanks Josh(I meant), you made me more smarter today .

 

When using B20 there is no need for any additional additives for lubricity or cetane.

Page 171 http://www.nrel.gov/docs/legosti/fy98/24089.pdf

Cetane Number

The cetane number of the fuel, specified by ASTM D-613, is a measure of its ignition quality. The cetane number of biodiesel exceeds that of #2 diesel, which implies that biodiesel may provide cetane enhancement when used neat or in blends, and may provide emission benefits that have been correlated to cetane number. Higher cetane numbers (as high as 55 to 60) generally improve diesel emissions, but above that level little improvement is demonstrated.

The cetane index is a calculated property that correlates well with cetane number for natural petroleum stocks, and is defined by ASTM D-976. Cetane index is also a measure of fuel aromaticity 62. It is not relevant to biodiesel.
The cetane number of biodiesel depends on the oil or fat feedstock. Fatty acids consist of long chains of carbon atoms attached to carbonyl groups. Fats and oils contain a distribution of carbon chains of varying lengths, typically ranging from 10 to 18 carbons (referred to as C10 to C18 chains). Some carbon chains contain 0, 1, 2, or more double bonds between the carbons, and have carbonyl groups in different locations. Cetane number increases with chain length, decreases with number and location of double
bonds, and changes with various locations of the carbonyl group. As bonds or carbonyl move toward the center of the chain, the cetane number decreases. Cetane numbers increases from 47.9 to 75.6 when the
number of carbons in the fatty acids in biodiesel increases (Freedman and Bagby 1990). When the number of carbons in the fatty acid chains exceeds C12, the cetane number exceeds 60. For soy methyl ester, reported cetane numbers range from 45.8 to 56.9. The variation is due to the distribution of carbon chain lengths in each fuel tested. The average of the available data presented in Table 108 is 51.3.

Generally, the cetane number for a blend of biodiesel and either #1 or #2 diesel fuel is a nearly linear function equal to the average of the cetane numbers for the fuels (Midwest Biofuels 1993; Graboski 1994). This implies that the neat cetane numbers for diesel and biodiesel can be used to estimate the cetane number over the entire range of mixtures of biodiesel with diesel fuel


I exclusively use Blusun B20 and have been using it since 2006. I currently use B20 as much as possible during warmer months, I do cut back in the colder months. The engine is quieter, smoother and I notice about .5-1 mpg improvement over standard diesel.

I am convinced when I see those that report only getting 15 mpg highway unloaded they are using inferior, low cetane diesel and further watering it down with Power Service or some other additive. I used Howes in 2006/2007 to help with gelling etc, but I feel addtives serve no real purpose other than 2 stroke oil in normal diesel.

Josh

 

Ok, if that's the case I'll run this tank down and try some B20.

 

Around here you can only get it at a VERY few places if at all.
I would run it if I could get it.


Sean

 

B20 and even B100 was more readily available until about 2008 and then it faded away. Not nearly as bad as E85 which has almost disappeared around here.

But even in Fort Collins there are 2 public stations with B20 and one city owned station with B20 and B100. Boulder, Colorado has more stations and even a few Co-oP stations with home brews.

The local Wal-Mart Muphy's station had B5-B20 for a while, but late 2012 dropped it. Even so, whatever diesel blend they have now rewards with better MPG and engine noise than many of the other normal diesel stations.

I had emailed Murphy USA asking why they dropped Biodiesel and the response was they are doing short term testing in each market.

Josh

 

Hmmm, Murphy has been selling it here for a few years now, that's where I normally get mine. I wonder if there weren't enough people buying it where you are?

 

It wasn't like there was a choice. When Murphys had it all the pumps were bio-diesel.



Josh

 

Well, no wonder they stopped carrying it...I bet they got a bunch of complaints from the gassers when they filled up with it.

Seriously, I meant maybe their sales of bio was not good. Are people in your area scared or opposed to it for some reason?

 

I don't believe anyone is scared of it here. At least not from March to October. I know Team Petroleum and Poudre Valley Co-Op sell the crap out of B20.

Although B20 is roughly .15-.20 cents more than regular diesel at those locations. When Murphy's had bio it ran about .10 cents less than average price. Even now Muphy's is roughly .05-.10 cents cheaper than most stations.

I would reckon it had to do with distribution versus consumers. Team Petroleum uses Blu-Sun (their website needs updated, as they were BluSun then Suncor and now back to BluSun) and Poudre Valley Co-Op uses Suncor B20.


Josh

 

A little off topic. Wille Nelson used to store his tour bus in a warehouse in old town, he used bio diesel. People used to say when it drove thru town it allways smelled like french fries. LOL

 

Could be true. I work with an old timer who brew his own diesel fuel from used restaurant oil in a 7.3 and I'd does smell like French fries. I think that's a different brew from the bio and bio blends that come out of the pump though.

 

Go to Biodiesel Fill Stations and Prices to show bio-diesel stations in your area.

 

That explains why the Walmart near me couldn't decide whether they wanted to carry it or not.

One time it would have B5, the next time you went back B20, then the next time the regular, dry ULSD.

As it stands now, the stickers on the pumps say that there's anywhere between a 5% and 20% bio-mix.

 

If it hasn't been mentioned here, know that bio is a better solvent than dino diesel and upon using it for the first time it will dissolve whatever crap is built up in your fuel system and may clog up the fuel filter(s). Other than that I've run B100 all summer when I could get it and the truck runs great.