More Poor Man's Octane Research - LOL
12-03-2010, 09:37 AM
#32
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I don't want to be a jerk, but much of the language you're using is somewhat incorrect, and may cause confusion. So for clarity:
Toluene (C7H8) has one more carbon atom than benzene (C6H6), xylene (C8H10) has one more carbon atom than toluene, but napthalene (C10H8) has two more carbons than xylene but less hydrogen. I think the phrase "carbon has a very high anti know/auto ignition level" is meaningless. I believe it is more accurate to say "Unsaturated compounds (toluene, xylene, etc), highly branched alkanes (iso-octane) and alcohols have high anti knock/auto ignition levels". n-octane has just as many carbons as xylene but an octane rating of -10. So it's the branching and unsaturation that matters.
Xylene, Toluene and Napthalene are all similar to benzene, but not derived from it. It makes sense that higher levels of these compounds are what makes the difference in higher octane fuels to a degree. But I wonder if when you're adding toluene to 93 octane pump gas if you might go over the 30% limit you cite. At some point you may have to start adding methanol for it's higher octane rating and to prevent a very sooty burn. The contents of the octane boosters seem to support this. Like I said, there is more than just octane rating and the people who blend race gas might just know better than we do.
Sorry if this is annoying, but I think accurate language helps in these matters.
Toluene (C7H8) has one more carbon atom than benzene (C6H6), xylene (C8H10) has one more carbon atom than toluene, but napthalene (C10H8) has two more carbons than xylene but less hydrogen. I think the phrase "carbon has a very high anti know/auto ignition level" is meaningless. I believe it is more accurate to say "Unsaturated compounds (toluene, xylene, etc), highly branched alkanes (iso-octane) and alcohols have high anti knock/auto ignition levels". n-octane has just as many carbons as xylene but an octane rating of -10. So it's the branching and unsaturation that matters.
Xylene, Toluene and Napthalene are all similar to benzene, but not derived from it. It makes sense that higher levels of these compounds are what makes the difference in higher octane fuels to a degree. But I wonder if when you're adding toluene to 93 octane pump gas if you might go over the 30% limit you cite. At some point you may have to start adding methanol for it's higher octane rating and to prevent a very sooty burn. The contents of the octane boosters seem to support this. Like I said, there is more than just octane rating and the people who blend race gas might just know better than we do.
Sorry if this is annoying, but I think accurate language helps in these matters.
Correct, the anti knock is more based on being a branched alkane as compared to a straight chain alkanes and then the key to the carbon atom, from what I was reading, is more based on the isomer of each chemical; structure of the atoms is the key as you mention. I guess I was thinking out loud with the reference to each chemical having a higher carbon atom and carbon itself having a very high auto ignition point, 1292F. LOL
I am by no means a chemist, just got a bug for researching fuels and additives, octane derivatives, etc. And as the title of the thread reflects a cheap source of octane. So there is my disclaimer.
Yes, methanol would be ideal due to its clean burn and high octane.
12-03-2010, 09:53 AM
#33
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Correct, heavy and light does not directly mean higher or lower octane, however, as it turns out the "light" naptha has an auto ignition temp of 444F and "heavy" of 1022F. Figueres based on several MSDS sheets.
12-03-2010, 10:03 AM
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Also, I am not posting to try to prove right or wrong, I just want to find out what is correct and correct myself if need be.
"Toluene, formerly known as toluol, is a clear, water-insoluble liquid with the typical smell of paint thinners. Chemically it is a mono-substituted benzene derivative, i.e. one in which a single hydrogen atom from the benzene molecule has been replaced"
"IUPAC Name: Methylbenzene"
"The term xylene or xylol refers to a mixture of three structural isomers of the aromatic hydrocarbon dimethylbenzene"
"IUPAC Name: Dimethylbenzene"
"A naphthalene molecule is derived by the fusion of a pair of benzene rings. (In organic chemistry, rings are fused if they share two or more atoms.) Accordingly, naphthalene is classified as a benzenoid"
12-03-2010, 11:16 AM
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12-03-2010, 12:24 PM
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You're not misreading, just infering that if a compound has a "benzene ring" then it must have come from benzene, which isn't the case. The aromatics have similar molecular structures (aromatic rings). These are sometimes referred to as "benzene rings" since the ring structure was first identified in benzene.
12-03-2010, 02:08 PM
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You're not misreading, just infering that if a compound has a "benzene ring" then it must have come from benzene, which isn't the case. The aromatics have similar molecular structures (aromatic rings). These are sometimes referred to as "benzene rings" since the ring structure was first identified in benzene.
12-03-2010, 05:50 PM
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Red bull will make your gas tank fly right out of the car.
At some point don't you just need a bigger intercooler? Surely this will cost less in the long run.
At some point don't you just need a bigger intercooler? Surely this will cost less in the long run.
