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Ni3Frontier 04-23-2003 06:38 AM

Re: Re: MTBE
 
[QUOTE][i]Originally posted by Tommy3rd [/i]
[B]Ethanol and Methanol is a smaller molecule than MTBE, so I don't think that's the reason. There were a lot of complaints from people being allergic to MTBE, but that was when they found out it had MTBE. Little did they know that MTBE was in gasoline 20 years ago and people never really said anything. In fact, way back then the maximum MTBE amount allowed was 15%, which yields an oxygenate content greater than 3.0
now, the max i've seen is 2.7 [/B][/QUOTE]

I dont understand much about oxygenated gasoline other than the fact that oxygenated gas is better for emissions but fuel economy suffers. You seem to know a bit about it; I'd like to learn more.

What is the oxygenate content number mean? Why is oxygenated gas required in the summer, but not winter in some areas (Woodbridge, VA my hometown).

Jsunn 04-23-2003 07:42 AM

From A Pilot...
 
Jet Fuel as have been stated is primarily Kerosene a lot like diesel fuel. It also has a much higher flash point than regular gasoline, meaning that it takes more heat to cause ignition. Jet fuel comes in many different forms, from JP-4, JP-5, and JP-8, for military fields and Jet A and Jet B for commercial fields. The main difference between them are the chemical additives that are added to the fuel to prevent corrosion, biological growth, and icing in the fuel lines and tanks.

Also a "TURBO-PROP" is a propeller that is driven by a jet engine through a reduction gearbox and thus uses jet fuel not av-gas.

Your smaller single engine prop planes and smaller dual prop jobs have reciprocating engines and use high-octane av gas.

Catch ya on the flip side.

-J

Tommy3rd 04-23-2003 02:36 PM

Re: Re: Re: MTBE
 
[QUOTE][i]Originally posted by Ni3Frontier [/i]
[B] You seem to know a bit about it; I'd like to learn more.

What is the oxygenate content number mean? Why is oxygenated gas required in the summer, but not winter in some areas [/B][/QUOTE]
Sorry buddy, i used to test petroleum products...that's the reason i know a little about it. You'll need a petroleum engineer/petroleum chemist to explain more about the dynamics of it.
oxygenate is just the oxygen content by % weight in gasoline.

to find out more about RFG (reformulated gasoline) and oxygenates, try the EPA site: [url]http://www.epa.gov/otaq/rfg.htm[/url]
The Clean Air Act is what started it all.

Also, thanks to the pilot for clearing some stuff..i always thought the "turbo-prop" meant propeller driven engines like the cessna with the propellers in the front.

Jejunum 04-23-2003 02:47 PM

[QUOTE]Ethanol and Methanol is a smaller molecule than MTBE, so I don't think that's the reason. There were a lot of complaints from people being allergic to MTBE, but that was when they found out it had MTBE. Little did they know that MTBE was in gasoline 20 years ago and people never really said anything. In fact, way back then the maximum MTBE amount allowed was 15%, which yields an oxygenate content greater than 3.0[/QUOTE]

im pretty sure ur wrong.. MTBE is a dangerous carcinogen and even in small quantities contaminates ground water; i believe that the real reason it was banned from use

Br1t1shguy 04-23-2003 04:36 PM

Do you have the SLIGHTEST understanding of what octane does? Since you're asking to put jet fuel in you're car obviously not, that is unless you're going to be running like 20:1 c/r or 40lbs of boost on 10:1 or something. If not you just made me dumber...

Tommy3rd 04-23-2003 04:54 PM

[QUOTE][i]Originally posted by Jejunum [/i]
[B]im pretty sure ur wrong.. MTBE is a dangerous carcinogen and even in small quantities contaminates ground water; i believe that the real reason it was banned from use [/B][/QUOTE]
i did not say MTBE isn't carcinogenic. i only said it's a bigger molecule than ethanol and methanol. I don't know why it was banned but i don't think it has anything to do with its molecular size. If there were leaks detected, then it could be caused by other things too, not necessarily because of MTBE.

Ni3Frontier 04-23-2003 05:28 PM

Re: Re: Re: Re: MTBE
 
[QUOTE][i]Originally posted by Tommy3rd [/i]
[B]Sorry buddy, i used to test petroleum products...that's the reason i know a little about it. You'll need a petroleum engineer/petroleum chemist to explain more about the dynamics of it.
oxygenate is just the oxygen content by % weight in gasoline.

to find out more about RFG (reformulated gasoline) and oxygenates, try the EPA site: [url]http://www.epa.gov/otaq/rfg.htm[/url]
The Clean Air Act is what started it all.

Also, thanks to the pilot for clearing some stuff..i always thought the "turbo-prop" meant propeller driven engines like the cessna with the propellers in the front. [/B][/QUOTE]

Thanks for the links! I read about the oxygenated gas in certain cities. My area is definitely one of them. So if oxygenated gas burns more completely, why does it decrease mileage and performance?

RichiQY 04-23-2003 05:44 PM

hmmm let me ask a dumb question

Tommy3rd.. whats the effect of adding alcohol in perspective to the engine and power generated?

and when you said adding too much is not good.. what harm does that do?


thx a lot..


one of the best thread i ve read on i-club..

:D

Tommy3rd 04-23-2003 06:00 PM

i remember asking one of the petroleum chemists that question. I think he said methanol/ethanol is too light/volatile that it messes with the ignition properties of gasoline.
I'm assuming you'll get ignition before the gases are fully compressed or the energy it generates when ignited is not as powerful as something with larger hydrocarbons.

sike43 04-23-2003 06:01 PM

hey there Br1t1shguy
 
im gunna keep this short and sweet , i think u made ur self dummer responding to this topic i dont wanna say anymore kuz were on a forum.

Jejunum 04-23-2003 06:52 PM

[QUOTE]Tommy3rd.. whats the effect of adding alcohol in perspective to the engine and power generated? [/QUOTE]

u didnt ask me but ill throw my 3 cents in anyways


a big problem with adding ethanol to gas is the fact that it has such a high percentage of water. Its azeotrope point, as I remember something like 89% - this means that 11% of it is water. You can get higher %'s of ethanol (of course) but its expensive. In addition if one leaves like a bottle of 99.9% ethanol out in the air it will absorb water to reach equilibrium...

and we all know water doesnt belong in our gas

Cycloexane 04-23-2003 07:55 PM

Ethanol apparently helps to produce cleaner emissions. It doesnt necesarily have any water in it (although anhydrous ethanol is much more expensive than ethanol denatured with ketones/methanol/water). Its also not very volitile. 87 ocatane gasoline is much more volitile than ethanol (but perhaps not methanol).

I used to pump gas at an airport... and Jet-A (jet fuel/aviation kerosine) is heavy, sticky, very non volitile stuff. Av-gas, was 110 octaine low led fuel, much like gasoline. Some guys i worked with used to put a half gallon or so in a nearly full tank, and it apparently really boosted their power.

RichiQY 04-23-2003 08:08 PM

[QUOTE][i]Originally posted by Jejunum [/i]
[B]u didnt ask me but ill throw my 3 cents in anyways


a big problem with adding ethanol to gas is the fact that it has such a high percentage of water. Its azeotrope point, as I remember something like 89% - this means that 11% of it is water. You can get higher %'s of ethanol (of course) but its expensive. In addition if one leaves like a bottle of 99.9% ethanol out in the air it will absorb water to reach equilibrium...

and we all know water doesnt belong in our gas [/B][/QUOTE] hmmm

absorb water part is making good sense

by running high boost. water becomes a good thing.. it can lower the detonation threshold by lowering temperature as compression ratio increase.


and under those situations . water is combustable..(correct me if i am wrong here pls)

NothingToLoose 04-23-2003 09:38 PM

RichiQY
Your kinda right. But the water is introduced into the system wrong. When water is introduced into the engine the corect way it mainly cools the air and fuel. Thus reducing detination. Im not quite the chemist some of these guys are so im not going to get any further into it. But i would like to here thier responce.. Im pretty shure im right.


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