Tetra-ethyl lead

Missa said:
He didn't seem to want to educate to begin with. He said he didn't think it sat around degrading but gave nothing more then his thoughts and then other people gave contridictory explainations and he just said. I disagree, enough said. I have no idea his petigree and he doesn't want to explain why he thinks mogas is infiniatly stable so I can only give him the credit he is showing...
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This is an interesting thread and I've not read all the posts. To this point, with any topic I believe that the value of a good premise can be lessened by a bad presentation; and this thread is such an example. Missa really needs to learn how to spell. Doing so will elevate said presentation.

HR
 
- - - and said calendar, with good weather, reminded me to start the Austin Healey and give it the April exercise outside my hangar. Stored since late October, it started quickly.
As a side note, it had been full of 100LL aviation fuel since late October.

HR
 
Lawreston said:
- - - and said calendar, with good weather, reminded me to start the Austin Healey and give it the April exercise outside my hangar. Stored since late October, it started quickly.
As a side note, it had been full of 100LL aviation fuel since late October.

HR
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A year or so ago I decided to use a trail bike that had been in storage for a number of years. Before putting it away I had drained out all the gas and replaced it with 100L (and ran it for awhile to make sure all the old gas was gone), It needed a new battery, of course, - but having installed same, started right up.

I think everyone agrees that avgas is quite stable. My unscientific observation (with motorcycles and lawn mowers) is that the current unleaded mogas is a lot more stable than the old leaded mogas was. I haven't had any problems with fuel systems getting gummed up in recent years (used to be a common occurrence).

Can anyone familiar with refining oil explain why? (I suspect that it has to do with producing motor fuel by distillation as opposed to catalytic cracking).

Dave
 
Back to the number of tanks at gas stations discussions. Here in MO, *most* stations typically have 3 grades, 89, 91 and 93. *Most* stations typically have two tanks and the mid-grade is a 50/50 blend of the two.

In reference to the one hose for numerous grades comments. The local gas pump sales/repair guy told me that there's only about 1/2 gallon on the secondary side of the selector pump but that, yes, your first 1/2 gallon will be whatever grade the last person pumped.

In MO you can get premuim w/o ethanol. All regular gas is required to be a 10% blend, and almost all stations blend premium w/ ethanol also because it's easier, but a few stations have ethanol free 93 octane. So, when I'm getting fuel for my plane, I always pump the first few gallons into whatever vehicle I'm driving to make sure I flush out what's on the secondary side of the selector valve.
 
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jesse said:
You don't handle someone disagreeing with you well do you? Respecting the thoughts of others is pretty damn important to having a constructive conversation. You were making statements that weren't respectful and he stated he disagreed and left it at that. I'm not sure why you think he is obligated to tell you anything.

No one is obligated to do anything for you. Airplane rides or chemistry explanations. The more you act like they are, the less interested they'll be.
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Uh no, I stated what I had observed and he dismissed it out of hand without bothering to explain why.

I'm not owed anything by anyone nor do I owe anyone anything. But if you are entering a discussion don't expect me to give you much credit if all you say is I dissagee and give nothing to back it up. Discussion is more then people speaking to hear themselves talk, discussion and debate is a way for people to gain knowlage by either understanding why what they thought is wrong or having their view reinforced. I am intrested in learning something but I learn nothing by people who simply state I disagree and I give those people all the credit they deserve with such a statement.
 
In 2002, total avgas production in the United States was 0.76 million gallons per day,4 a very small amount compared to the production of turbine fuel (68 million gallons per day) or motor gasoline (372 million gallons per day).Worldwide use of avgas in 1996, by the most recent data available, is estimated to be about 2.2 million gallons per day.
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From the attached very informative read.
 

Attachments

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Missa said:
Uh no, I stated what I had observed and he dismissed it out of hand without bothering to explain why.

I'm not owed anything by anyone nor do I owe anyone anything. But if you are entering a discussion don't expect me to give you much credit if all you say is I dissagee and give nothing to back it up. Discussion is more then people speaking to hear themselves talk, discussion and debate is a way for people to gain knowlage by either understanding why what they thought is wrong or having their view reinforced. I am intrested in learning something but I learn nothing by people who simply state I disagree and I give those people all the credit they deserve with such a statement.
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Missa- I'll try one more time... much of what I posted was repeated by others. If someone else posted something I would have said, I simply chose not to repeat it.

The base fuel for Mogas and Avgas are the same basic hydrocarbon mixture. What makes them different are the additives. Mogas can have up to 50%(!) additives. What the additives are depends on the season, the state, and politics (in NE, 89 octane Mogas costs less than 87 octane where I shop because it "enriched :rolleyes:" with 10% ethanol). These additives profoundly affect Mogas stability (note the post on MTBE sometime earlier). Some additives evaporate from the fuel more quickly, which causes the gasoline to behave differently in some engines. Some additives allow microbial growth more than others, other additives inhibit it. The microbial growth clogs fuel injectors and carburator jets. The good thing about these microbes (some of them) is they help us to mitigate oil spills.

The additives range from benzene, toluene, xylene, through methanol. Benzene, toluene, and xylene are called "aromatic" hydrocarbons. They reduce detonation. If you want more information, let me find references this weekend and post them. Ok?
 
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dmccormack said:
Yep -- I know. But there aren't 5 different tanker trucks filling the underground tanks at the Sunoco station.

:dunno:
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Actually there's one truck with 3 different containers in it, I believe.

EDIT: I see this has been covered. I TRY to read through the whole thread before replying... but sometimes ah forgets.
 
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Missa said:
And what would result if your crusher got bad gas??? Would anyone die or would you just fail to crush a car?

Engine problems in a plane on take-off =/ engine probems in a car crusher.
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I never said that I'd be willing to fly on 4 yr old gas. I was just commenting on the stability of gas that had sit in cars on a junkyard lot. Two different points altogether.
 
Jeepers -- bitter disagreements about GASOLINE?????:frown3:

My solution is much simpler -- go for the turboprop!!:D:D
 
Cap'n Jack said:
Missa- I'll try one more time... much of what I posted was repeated by others. If someone else posted something I would have said, I simply chose not to repeat it.

The base fuel for Mogas and Avgas are the same basic hydrocarbon mixture. What makes them different are the additives. Mogas can have up to 50%(!) additives. What the additives are depends on the season, the state, and politics (in NE, 89 octane Mogas costs less than 87 octane where I shop because it "enriched :rolleyes:" with 10% ethanol). These additives profoundly affect Mogas stability (note the post on MTBE sometime earlier). Some additives evaporate from the fuel more quickly, which causes the gasoline to behave differently in some engines. Some additives allow microbial growth more than others, other additives inhibit it. The microbial growth clogs fuel injectors and carburator jets. The good thing about these microbes (some of them) is they help us to mitigate oil spills.

The additives range from benzene, toluene, xylene, through methanol. Benzene, toluene, and xylene are called "aromatic" hydrocarbons. They reduce detonation. If you want more information, let me find references this weekend and post them. Ok?
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Your terminology is unusual. Mogas typically is made up of hydrocarbons in the C4-C9 range and include normal paraffin’s 10-15% (low octane & stable), isoparaffins 35-45% (high octane & stable), cycloparaffins 10-15% (low to high octane & stable), aromatics 20-35% (high octane & stable), olefins 6-15% (high octane & UNSTABLE) and oxygenates 10% (high octane & mostly stable). They include additives such as antioxidants, metal deactivators, anti-icing, and corrosion inhibitors and deposit clean-up in miniscule amounts (10-300ppm).

Avgas is usually made up of one normal paraffin (butane 1-3% high octane and stable but volatile) isoparaffins 75-85% and aromatics 15-25% and TEL and can be thought of as butane 2% (vapor pressure), isopentane 15% (vapor pressure), isooctane 63% (octane and energy content) and toluene 20% (octane). It is the olefins in mogas that are unstable (they form varnish and gum) and stink. They are used to raise octane. They are not used in avgas.

TEL raises the octane of isoparaffins very well. Mogas is more volatile than avgas.

There is a lot of data demonstrating Cont IO-520/550 and Lyc IO-360 engines running with moderate detonation using 100LL. It is worse for the turbocharged engines. These engines need 100+ MON fuel.

Ed

Edward Kollin
Technical Director
Aircraft Specialties Lubricants
 
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Edward Kollin said:
Your terminology is unusual. Mogas typically is made up of hydrocarbons in the C4-C9 range and include normal paraffin’s 10-15% (low octane & stable), isoparaffins 35-45% (high octane & stable), cycloparaffins 10-15% (low to high octane & stable), aromatics 20-35% (high octane & stable), olefins 6-15% (high octane & UNSTABLE) and oxygenates 10% (high octane & mostly stable). They include additives such as antioxidants, metal deactivators, anti-icing, and corrosion inhibitors and deposit clean-up in miniscule amounts (10-300ppm).

Avgas is usually made up of one normal paraffin (butane 1-3% high octane and stable but volatile) isoparaffins 75-85% and aromatics 15-25% and TEL and can be thought of as butane 2% (vapor pressure), isopentane 15% (vapor pressure), isooctane 63% (octane and energy content) and toluene 20% (octane). It is the olefins in mogas that are unstable (they form varnish and gum) and stink. They are used to raise octane. They are not used in avgas.

TEL raises the octane of isoparaffins very well. Mogas is more volatile than avgas.

There is a lot of data demonstrating Cont IO-520/550 and Lyc IO-360 engines running with moderate detonation using 100LL. It is worse for the turbocharged engines. These engines need 100+ MON fuel.

Ed

Edward Kollin
Technical Director
Aircraft Specialties Lubricants
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I'll grant you my terminology is unusual to someone that works in the industry; I don't. I was taught in the 80's that "paraffin" was an older name for "alkane"; Rechecked, my reference is Organic Chemistry, Morrison and Boyd, 3rd Edition, Allyn & Bacon, p1249. Likewise the term "iso" is probably used mostly by the petroleum industry anymore. Except for "normal", as the prefix "n-", I don't recall seeing these terms in IUPAC nomenclature. Likewise I rarely hear "olefin" anymore; I hear it as "alkene". I'm not saying you are wrong...just explaining the difference.

How much of the aromatics and alkenes are added to either fuel?

EDIT: I think you'll find that the alkenes do not have to be present in MoGas or present in variable quantities, which probably accounts for the variability in stability. One person mentions their Mogas is very poor and doesn't last long; the other person can keep their Mogas for years; I will not discount either observation.

I would expect that biodiesel fuels would have a similar issue with stability- the fatty acids tend to be punctuated with double bonds depending on the oil source.
 
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Cap'n Jack said:
I'll grant you my terminology is unusual to someone that works in the industry; I don't. I was taught in the 80's that "paraffin" was an older name for "alkane"; Rechecked, my reference is Organic Chemistry, Morrison and Boyd, 3rd Edition, Allyn & Bacon, p1249. Likewise the term "iso" is probably used mostly by the petroleum industry anymore. Except for "normal", as the prefix "n-", I don't recall seeing these terms in IUPAC nomenclature. Likewise I rarely hear "olefin" anymore; I hear it as "alkene". I'm not saying you are wrong...just explaining the difference.

How much of the aromatics and alkenes are added to either fuel?

EDIT: I think you'll find that the alkenes do not have to be present in MoGas or present in variable quantities, which probably accounts for the variability in stability. One person mentions their Mogas is very poor and doesn't last long; the other person can keep their Mogas for years; I will not discount either observation.

I would expect that biodiesel fuels would have a similar issue with stability- the fatty acids tend to be punctuated with double bonds depending on the oil source.
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I only meant that aromatics, olefins, oxygenates, etc. are not considered additives and "additive" treat rates are typically less than 1%.

Mogas is notoriously unstable due to the olefin's (alkenes) and while it does not have to contain any of these stinky molecules the commodity pressures dictate that it will.

Biodiesel is by nature biodegradable because of the double bonds you mentioned but does not form the gum of smaller alkenes used in mogas.

Ed
 
flyersfan31 said:
Jeepers -- bitter disagreements about GASOLINE?????:frown3:

My solution is much simpler -- go for the turboprop!!:D:D
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Hmm. Somehow I'm wondering when your signature will change to something about a PA-46-500 or whatever the Meridian designation is. :)
 
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