Gasoline composition..?
 

Hmmm.... What's this stuff we're pumping ? Any comments? :eek:

Its wet yellow and a bit stinky .. kind of reminds me of.........

Stinky?
 

Naw! That's just your upper lip! LOL!:D

Gas is BAD, unless it's part of a 170 proof mixed drink for my car.

Any new replies?
 

Hmmm.... I had hoped to start a serious discussion on gasoline composition / quality...but I guess I'm ****ing in the wind! :confused:

Gasoline is a complex mixture of hydrocarbons of various shapes:

Aliphatic (saturated, i.e. with no double bonds) straight chain hydrocarbons such as hexane
Aliphatic branched chain hydrocarbons like "octane" (2,2,4 trimethylpentane)
Olefinic (unsaturated, containing double bonds) chains, such as hexene
Aromatic, unsaturated rings, such as benzene or toluene.
Cyclics, like cyclohexane.
And recently, oxygenates like methyl tert-butyl ether or ethanol.

The type of each compound depends on the individual oil well from which the gas was distilled, the amount of "cracking" to make gasoline from heavier oils, and the amount of "reforming" smaller molecules to make gasoline.

Methyl tert-butyl ether is made from nautral gas in a chemical synthesis, and ethanol is made by distilling fermenting sugars.

I would be interested in this too since I don't know squat about petro. Ted Why don't you get the ball rolling. All I know is that there are a bunch of hydrocarbons (500) and that the octane rating of gas before they start adding additives is around 70. A good percentage of gas 35% is aromatics including benzine and tulene(sp). I also think that there is a difference in gas performance depending on the additive package and that it could be tweeked to deliver better mileage.

I think it was Remy that said if we burnt gasoline properly we would end up breaking down the Hydrocarbons into water and solid carbon. If only we could get plants to make hydrocarbons . . . hummmmm

hehe change the wet and yellow into crystal and green and you got WIIIIIIIIIIIIIIIIII D ;)

i find it hard to believe people get kicks by sniffing gasoline.... the brain MUST LOVE IT!

starting this ball rolling...
 

Hi, "zipiloto"! Well! a rational response....
You're right...there are literally hundreds of different compounds in gasoline! Complex stuff! How many? Not important....However, we can break this down into two (rough!) classes...that which vaporizes (the aromatics), and that which doesn't. What is which? We'll get to that, later.
I had noticed...in my earlier(fuelish?) years...gasoline would vaporize quickly! All of it! Using gasoline for washing car parts ( back off, critics! LOL!) would result in dry parts in a few minutes, and rust on ferrous / iron-based parts overnight... if a coating of oil / paint were not applied quickly.
A related observation : the slight amount of (dirty) gas left in the can would either be a sticky gell the following day, or be gone (dry) altogether!
Recent gas...in the last decade or two (3?) behaves differently. For example...pour a slight amount on a hard surface (not porous)... come back hours later...and the spot is still wet! Some part of the gas does not evaporate! How much? Hmmm.... How to find out...?
I took a page from recent bench studies I had done...plugged these "ideas" into an air compressor, regulated the output( to maintain a steady flow), rigged up a long-necked glass container...from my "neat junque" collection...to measure gasoline volumes, drew a scale...taped it to the neck, filled the container such that a "start" point was marked on the scale. Then I placed the steady-state air flow hose down into the liquid gasoline...at the same time starting a stopwatch. 15 seconds of bubbling...pull the hose out, mark the "new" level of liquid gas. "Hey! It dropped!"
Zero the stopwatch. Repeat the air tube (still flowing) insertion into the liquid gas (same depth), wait 15 sec., remove tube, measure.... New level! As low? Mark it.
Repeat the inserting / stopwatch bit. Mark the "new' level at 15 sec. of runtime.
Repeat. Repeat. Repeat...until the level of the quiet gasoline was about the same as last time...indicating no (measureable) change had occurred. End of study. The container, however, still had quite a bit of liquid left in it!
Take the graduated scale ..."start" to "end of run", with all its 15 second divisions... and plot a graph (semi-logarithmic) of gasoline volume at "start" to gasoline volume at "dry" (empty). Somewhere in the middle was the "end of run" mark.
Long story short , no graph to look at(it's stored away in my research files), gasoline was ... at the time of testing... 30ish % volatile, 70ish % non-volatile ! This was fresh 93 octane pump gas from a high-turnover dealer.
What was the non-volatile? Well, I did the only thing I knew to do(at that time & place)...see if it...gasoline?... would burn. A lit match dropped into a small metal bottle cap 1/2 full of this "residue" went out! So, I placed a wick of cloth in the little pool...lit the damp end of the wick. It slowly started burning ; got a little faster as it heated things up...and did it ever smoke! Dark, rolling clouds of smoke! The wind shifted, I caught a good whiff of ... diesel bus! What did this tell me? Right! ~70 % of a gallon of premium pump gas was diesel (or similar oils)! What is it now? Who knows! But I can tell you the gasoline of years ago evaporated to nothing more than a tan ring.
I also had a sealed, glass container of old 106 octane Union racing gas. I repeated this test with a sample of old racing gas...it all volatilized (vaporized). Every last drop! And this was years old! What does this say?
I then contacted a sorta local race engine builder...and talked him out of a quart or so of 112 octane racing gas he used for his dyno break-in runs (very fresh!)...took this gas back to the test rig...ran it through the study procedure (new graduated strip on the column), and... lo and behold! ~51 % is volatile! That means ~49 % is diesel.... Times change! I am not pointing any fingers, but you can smell this / these oils going into your gas tank!
I'll bet you didn't know your GAS engine could run on semi-diesel! This is the reason I developed my gas modifier( does it need modifying?LOL!). More bang for the buck....

haha, I'd have to agree with you on that one, I worked with an older gentlemen, who we actually nicknamed "crazylarry" One day we were looking for gas for the old snow blower, he finds the 5 gallon red jug, puts it up to his nose, and takes an ENORMOUS pull through his nose!! like an "i'm going to see how long i can hold my breath" pull!! I was sure he was going to die, but he didn't. Most likeley because he was already completely burnt out. He then told us "yup, that's gas" and left haha.

I would agree with you that there is a lot of other stuff in gas, but I doubt it's actually diesel, If you've ever accidently put diesel in your car you'll know why i say this ;) They will run usuually but they also produce billowing clouds of smoke, even if it's only a 1/2 tank of diesel, upping the percent in gas form say 50, to 75, shoudln't make this big of a change if it was truly diesel.

Ok so 50-70% of fuel is paraffins of some kind. So if you increase the amount of aromatics up from the current 35% won't this significantly increase green house gases? Also since now we have a more volatile mixture won't this cause heat related problem such as hot starts and ignition timing problems?
Keep it coming but keep it simple I'm not the brightest bulb on the porch:D

Was that gas summer blend or winter blend??

I hear what you are saying...but, remember, today's cars have enough 'afterburner" on 'em (EPA calls this a "catalytic converter") to burn off any residues left over from incomplete combustion. What does this scene do for diesel fumes? :confused:

Catalysts can burn off certain diesel pollutants, such as the aldehydes that cause the particular diesel smell. However, a catalyst normally can't burn off the carbon particles in diesel exhaust; and because diesels are always lean, three-way catalysts are useless for removing NOx.

New EPA regulations require soot filters that periodically are regenerated by overfueling the engine to make the exhaust hot enough to ingite the soot. EPA regulations are also requiring selective catalytic reduction of NOx using urea or ammonia. This technology has been used in pawer plants for a long time. When you fill up a new diesel, you have to fill up the pollution controls with ammonia or urea.

I think so far, Ted wins the prize for the longest composition on gasolline. :)

Interesting you should ask the "plants into hydrocarbons" question....
FYI, are you aware (my ex-neighbor was...he grew 'em!) castor beans can be "smashed" and chemically leached to extract the abundant oils in them...to burn in diesels? This entire episode took place many years ago; just about the time of the Arab Oil Embargo! He has since been "asked" to move back to Jamaica...overnight! I, too, have moved since then...everything changes.

Ted -

This ain't scientifical or anything, but I have recently noticed that when I gas up with Chevron, I get a better tank than when I gas up with 76. Now, this could be due to :

1 - Coincidence, where I am just having bad driving days after gassing up with 76 (the most likely explanation).
2 - The 76 station is watering down it's gas.
3 - Chevron has "something special" in it's gas that helps my MPG (least likely).
4 - My drivetrain just happens to appreciate Chevron gas over 76.
5 - My car has a crush on one of the Chevron toy cars and drives better.

What is your opinion? Do certain cars like certain brands of gas?

CarloSW2

It's flammable and is excellent for putting into molotov coktails.

The Nightrider!

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