Ethanol in gasoline

[Funny]

Originally Posted by Lazarus

Don't know about the E10 but stumbling with E85 on non FFV is common under load because the injectors are not putting out enough fuel not that there is water in the fuel.

Originally Posted by Christ

I would tend to agree with Lazarus here, as the fuel density of E85 is less than that of normal gasoline.

I don't want to start disagreeing with one of the other scientifically minded posters, but I think you have to think this part through, or maybe explain it a little better. Specific gravity (density) of these common liquids:

Liquid; Specific Gravity (grams per cubic centimeter)
Acetone CH3COCH3; 0.792
Alcohol - ethyl (grain) C2H5OH; 0.789
Alcohol - methyl (wood) CH3OH; 0.790
Diesel Fuel Oil 2D/3D/4D/5D; 0.81 - 0.96
Ethylene glycol; 1.125
Fuel oils 1/2/3/5A/5B/6; 0.82-0.95
Gasoline a; 0.74
Gasoline b; 0.72
Gasoline c; 0.68
Kerosene; 0.78-0.82
Toluene; 0.865
Water. fresh; 1.0
Xylene; 0.87

Found on Engineering Toolbox

All of these liquids (except water) are less dense than water, and gasoline is less dense than ethanol (ethyl) .

ChrisT, if you are talking BTU density, then I will agree with you. If you you are talking density as in mass-over-volume, I must disagree.

If the injectors are tuned for a specific density of fuel, then anything higher or lower in density would have problems being forced through, or dribbling out of, the nozzle of the injector. Please clarify your statement .

[Christ]

Well, fuel density, in this case, refers to BTU/volume. Incorrect terminology haunts me, sorry.

I understand what you're saying though, and even that is a correct reasoning for stumbling - The fuel might not be vaporized as much, thusly making it more liquid than vaporous, and causing stumbling due to the "lean" condition created therein. (Liquid fuel does not burn effectively, causing less surface area to consider for the fuel/air mixture, making it "lean") At least iirc, that's true.

However, if that were the case, adding Xylene/Toluene to fuel would raise it's specific gravity as a solution, which might also throw off the A/F ratio... which didn't happen in my case, at least not according to an A/F meter on a standard (non wide band) O2 sensor. It stayed in the same place before and after adding Xylene to the mix.

For corrective purposes, however, yes, I meant BTU/volume in that reply.

[DifferentPointofView]

Originally Posted by Funny

Just as a clarification to everyone, there is no such thing as 100% ethanol, it is unattainable in practical application because it is azeotropic. Reagent grade ethanol, the highest percent purity money can buy, is 99.8% percent. This is the highest one can obtain without putting ridiculous amounts of energy into it to drive off the water. Typical ethanol that one creates in a still, commonly known as "moonshine", is 95.6% ethanol, 4.4% water.

Wikipedia quote: "A well known example of a positive azeotrope is 95.6% ethanol and 4.4% water (by weight). Ethanol boils at 78.4°C, water boils at 100°C, but the azeotrope boils at 78.1°C, which is lower than either of its constituents. Indeed 78.1°C is the minimum temperature at which any ethanol/water solution can boil. It is true that a positive azeotrope boils at a lower temperature than any other ratio of its constituents. Positive azeotropes are also called minimum boiling mixtures."

Once ethanol is exposed to air, it immediately begins to remove moisture from it, thus becoming less and less concentrated the more exposure it receives. This is why cars have stumbling problems with E10 and E85, there is water in the gas tank. In most small engine power equipment, you will find a statement in the owners manual that tells you to not use gasoline with ethanol in it if possible because it creates moisture in the carburetor and problems such as condensation, hesitation, and frustration (This F'ing Thing Won't Start!!! *Beats mower repeatedly with a hammer*.



Again, fuel grade Ethanol is not 100%. Close, but no cigar.

Methanol, on the other hand, which is used in Heet, and other forms of "dry gas", is a great way to remove water from your gas tank. It doesn't form an azeotrope with water, and can be 100% pure. It is also completely soluble in both ethanol and water and, as such "pulls" the water out of the gas tank, through the fuel pump, and sends it through the combustion chamber.

I would be much more inclined to buy 5% Methylated Gasoline than E10. Even though the methanol reduces the overall BTU per gallon, you would effectively never have water in your gas tank. I hope this clarifies everything for everyone.

EDIT:
In response to the above post about wood being used to create ethanol...

"Methanol is often called wood alcohol because it was once produced chiefly as a byproduct of the destructive distillation of wood. It is now produced synthetically by a multi-step process: natural gas or coal gas and steam are reformed in a furnace to produce hydrogen and carbon monoxide; then, hydrogen and carbon monoxide gases react under pressure in the presence of a catalyst. Methanol is also produced from the gasification of a range of renewable biomass materials, such as wood and black liquor from pulp and paper mills."

Fine, E95.6

[Christ]

*pulls up to pump*

"Yep - you keep using your E85... I'll take some E95.6 in this puppy here... "

*slaps door of his oversized american 'replacement for male genitalia-mobile' heftily, while grinning*

First thing that popped into my head. :P

[Intrigued]

LOL! I thought only Corvettes qualified as the oversized american automobile!

...I wonder how much E95.6 it takes to make an E85 blend... starting to hurt my brains now...

[Intrigued]

Oh, and I can just see Frank Lee's avatar slapping a car and saying that!!!

[Christ]

So you want to know how much 95.6% ethanol it would take to make 100% gasoline into 85% ethanol? LOL.

I'm not going to work on it, but given the figures, a rough estimate would place it somewhere close to 89%, I believe. (88.74%)

Someone wanna do the real math?

[Funny]

95.6%/85% = 100%/X
Use Cross multiplication....95.6X = 8500

Therefore X = 88.9121% Ethanol, and 11.0879% Gasoline to make E85.

I am such a nerd... or is it the fact that I do this stuff every day at work?

[Christ]

Originally Posted by Funny

95.6%/85% = 100%/X
Use Cross multiplication....95.6X = 8500

Therefore X = 88.9121% Ethanol, and 11.0879% Gasoline to make E85.

I am such a nerd... or is it the fact that I do this stuff every day at work?

K, here's what I did in my head in 10 seconds:

100.0% - 95.6% = 4.4%

85.0(4.4%) = 3.74

85.0% + 3.74 = 88.74%

Yes, you're a n3rd. But so am I, so it's OK. We can be n3rd-fr3nz

[DifferentPointofView]

Originally Posted by Christ

*pulls up to pump*

"Yep - you keep using your E85... I'll take some E95.6 in this puppy here... "

*slaps door of his oversized american 'replacement for male genitalia-mobile' heftily, while grinning*

First thing that popped into my head. :P

Was that indirectly bashing my Jeep?

Just wondering. and frank lee's avatar did pop in my head as well.