Biodiesel and Ethanol

I wouldn't use anything, but real diesel, that bio stuff has algae problems, particularly in plastic tanks.  Who needs more headaches...

My BMW specified no more than 5% bio diesel. I think BMW was more concerned about quality than anything. I remember pulling into a Kum & Go and finding their pump labeled "may contain up to 20% bio diesel." I got back into my car and drove to the next station. At work I had a remote radio site that ran on solar with a diesel backup. It was really a generator with a solar assist. One year of bio diesel and the algae headaches caused me to become very particular about the fuel. This was stored in a steel tank, no less.

Edited by Lonn - 12 Oct 2018 at 6:09am

I've been of the opinion for some time that the issues with biodiesel can be solved with some good research and some smart chemists and chemical engineers working on it.  Maybe not, but I think so.  When economics demand it (if?), that work will begin more in earnest. 

With daily use,biodiesel isn't a problem....it's the setting that makes the ugly show up. So far,I can still get straight diesel off the tank truck.Still have rusty fuel tanks from one winter of bio....

Edited by SteveM C/IL - 12 Oct 2018 at 7:59am

I avoid ethanol when ever possible.  It is too hard on fuel system components.  My chainsaw will not start on ethanol.  Pure gasoline or 100LL works great in my chainsaw.  Even my saw dealer told me to not use ethanol gasoline.

Not going to get into any arguments, just my experience, have used 5% bio and 10% ethanal for 20 plus years, absolutely no trouble. Just my experience.

modirt wrote: BTU value of ethanol is about 70% or so of regular gasoline.

This is incorrect.

One gallon of 89 (RON) unleaded gasoline yields 124,000btu.

One gallon of ethanol yields 76,000btu. 

76,000 /  124,000 =  61.29%.  A little more than half the fuel energy.

The biggest issues with ethanol include:

1) It's polar, and caustic... ph 7.33, so it's a base.  It etches away the tank, fuel lines, and pot-metal castings of fuel system components... and includes it in heavier gasoline fractions and water as black goo.
2) it is extremely hygroscopic... it acts as a dessicant- will withdraw moisture from the air, even when in suspension with gasoline.
3) It's a carbohydrate, which means it will not dissolve into, or be dissolved by... a hydrocarbon.  It can only be in suspension, and if allowed to settle, it will stratify in layers with water precipitated to the bottom of the tank, followed by supersaturated ethanol, then gasoline's heaviest fractions, with the lighter ones allowed to evaporate off.  Evenutally, it turns to a nasty, black goo noted above.

The performance issue with ethanol blends, is that the flame speed of carbohydrate fuels, and the expansion curve pressures are totally different from gasoline.  Using a mixture of ethanol and gasoline in an internal combustion engine, is exactly the same as using a combination of wood-chips and black powder in a high-power rifle cartridge, or the converse... using a mixture of modern smokeless rifle powder and corn starch in a damascus shotgun barrel... or worse yet, trying to run a steam engine on dry pine slabs, or wet oak logs-  one cannot optimize for two different burn cycle constants at the same time, and ANY repeating burn cycle is substantially complicated by the inclusion of water.

If you build a fuel system from the git-go to utilize Ethanol, it's possible to get a really great result.  Same goes for methanol... my Grandfather distilled woodchips to make solvents AND fuel his Waterloo Boy sawmill engine during the fuel rationing of WW2... and it did just fine... but he didn't mix gasoline with it, and sure as heck didn't drink it...

Biodiesel's challenge, is that the bio part is naturally very uncontrolled at times... and it's character is very subject to seasonal challenges.  I've had plenty of friends with good experiences with bio in trucks they run on bio they produce on their own... they make their own production systems, and fit up their trucks and Jeeps, running on old-time mechanical injection turbodiesels... and they do just fine (aside from government regulations having a fit over not paying road-fuel taxes, right?).  I've got a buddy who uses home-brew bio in a Lister, and it generates power and heat for his hunting cabin just fine.   I've run bio grades in my company service truck, and had many instances where it was just fine, but I've had plenty of instances that gelled up lines, plugged up filters and ruined injection pumps... so we don't run diesel service trucks anymore.

From an engineering standpoint, it's best to build it to run on one, or the other, and from that, you can have a great system.  Don't mix 'em, it just makes a terrible pile of variables with which to contend.

EPA tests have proven that you get about 4% less MPG with E10. Your pump price should reflect this. $3.00 regular gasoline should mean that E10 would be priced at $2.88. Unless your state gives a motor tax break on E10, you are quietly paying a little more in road tax. Here in Iowa regular is priced at 30 cents above E10, across the board and everywhere. I wasn't a resident here when all that went into effect, but I suspect that regular gasoline is being taxed at a much higher rate. Regular gasoline here is priced well above the national average. E10 is priced near the national average.

Got to love politicians and their rose colored vegetable powered world glasses. Just remember, You will do it and You will like it, we have ways of making You like it, now do it.

AC7060IL wrote: Bio fuels need to be used, not stored.

This advice is paramount...  When ANY blend exists, this is when all bad things have time to happen.  Keep it fresh and moving, and one will have the least issues.

So what's this low sulfur stuff about? What's the sulfur for?

I been looking at all my local diesel places, they all seem to be doing Bio. Not a Shell near me that sells diesel.

Coke wrote: So what's this low sulfur stuff about? What's the sulfur for? I been looking at all my local diesel places, they all seem to be doing Bio. Not a Shell near me that sells diesel.

I *think* the railroads still use diesel with sulfur. Don't quote me until you've looked it up. In any event, I doubt you'll be able to purchase any fuel from them. Modern diesels with pollution equipment hanging on them require Ultra Low Sulfur fuel. "They" say you should add a lubricant to your fuel if you are running older equipment that was designed for older diesel fuel. I've looked up some diesel fuels and some claim to have added a lubricant of their own, depending on location. This makes me wonder if some oil companies even sell their own brand of diesel fuel or if they just market some generic stuff.

Unusual that you can use 87 octane in your chain saw. I have three two cycle pieces of equipment and the manufacturers both recommend premium fuel. As little fuel as they use, I just fill my mix can with premium.

Is that just Indiana? I've seen a lot of pumps round here that say all gas may contain up to 10% ethanol, and that's all the selections, not just the 87.

As to the biodiesel, I know for sure a bunch of places round here get their diesel from a different place than they get their gas, some even have stickers to that effect.