Talk:Gasoline/Archive 1

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Lead, additives, environmental effects

The environmental effects of lead in gasoline are extremely difficult to measure and have not been measured in real world settings. Theory suggests that there should be some bad effects, but it is very unclear if these should be called "major". There has been and still is some controversy about this.

off the top of my head, lead is emitted along with the exhaust gas as volatile halides as well as particulate oxides. It is a proven neurotoxic, especially in children.--134.121.3.150 18:00, 23 Feb 2004 (UTC)

Also lead was used in high performance military gasoline during WW2. I'm not sure if it might be even older than that. "1960s" is certainly too late for its introduction.

The form of lead used in gasoline is tetra-ethyl lead.

There are several lead substitutes used in modern lead-free gasoline:

dimethyl sulfur: smells horrible. Slightly corrosive to engines. Not sure if it is dangerous. This was used in small quantities back to the 1930s. The amount used is now much higher in some countries where cheap high octane gasoline without lead is desired.

is there a reference on this useage? sulfur heterocompounds are usually inherited from the crude oil as mercaptanes, dialkylsulfides and disulfides. While they can act as radical traps (anti-knocking), their effect on the octane number is weak. Following burning in the engine, toxic sulfur oxides generally denoted as SO_x are formed.--134.121.3.150 18:00, 23 Feb 2004 (UTC)

aromatic hydrocarbons (especially benzene, toluene, xylene): Really seriously poisonous and carcinogenic. Much more dangerous than lead. Slightly corrosive to some engine parts. Civilised countries limit these by law to a very small percentage. These are present to some extent in crude oil, and small quantities have always been present in gasoline.

commercial, or pump, gasoline is actually a blend of several fractions, or components, originating both from the primary processing (distillation) and from the secondary processing (which includes conversion.) Most of the aromatics are added as a fraction called reformate, which is obtained in the catalytic reforming (a.k.a. platforming) process. Aromatics have a very good octane rating, however, they tend to generate increased carbon particulates in the exhaust (black smoke), and the vapors emitted are carcinogenic, as mentioned.--134.121.3.150 18:00, 23 Feb 2004 (UTC)

branched hydrocarbons: comparitively safe, but they add significantly to the cost, given the large quantities needed.

again, i think this needs to be clarified: pump gasoline is a blend of fractions. On the one hand we have the so-called straight-run gasoline, which is a product of distillation from the crude oil, and inherits the chemical profile of the crude blend. On the other hand we have the commercial gasoline blend(s) which has to conform to commercial standards (octane number, point of crystallization, polymer formation potential, moisture content, acidity, vapor pressure) as well as to regulatory standards (emissions by evaporation, sulfur content, total aromatics, benzene, total oxygenates). The lists in parantheses are not exhaustive. The different blends are made up of similar components and additives in different proportions optimized to yield the desired properties. The blending process is half art half empirical science.--134.121.3.150 18:00, 23 Feb 2004 (UTC)
Oxygenates are other high-octane components of gasoline that allowed the complete phase-out of lead. They include alcohols and ethers. Methanol is -I think- widely used, although exposure to vapors and liquid can cause irreversible blindness. MTBE (methyl-tert-butyl-ether) is notorious in that shortly after virtually all refiners invested in plants, the ether was found to easily contaminate aquifers and bans were considered in California and Connecticut. Don't have current information on this to hand.--134.121.3.150 18:00, 23 Feb 2004 (UTC)
MMT (Methylcyclopentadienyl Manganese Tricarbonyl if you must know) is used in Canada (for a long time) and Australia (recently) to boost octane...also helps old cars designed for leaded fuel to run on unleaded fuel without need for additives to prevent valve stem problems. It's the Manganese that has the effect.

--GPoss 10:21, Jul 22, 2004 (UTC)

Someone should write something about Ignacy Łukasiewicz. He discovered the paraffin lamp and opened the world's first petroleum refinery in 1856. [[1]]

Q&A's

--QUESTION What is the generated heat (J/kg) obtained by burning gasoline?

--ANSWER

Fuel      kJ/g     kwh/kg
Kerosene  48       15.5 
Gasoline  50 
Diesel    45       15.5

--QUESTION What is the freezing point of gasoline?

Being a mixture of various components, gasoline does not have a well-defined freezing point. Depending on the region where a blend is sold, the so-called crystallization point, or clouding point, should be lower than the expected minimum temperature in that specific region. Complete freezing occurs at a much lower temperature. Will return with some numbers soon.--Unconcerned 08:52, 8 Jun 2004 (UTC)

From PNA/Chemicals

  • Petrol#World_War_II_and_octane has received some anonymous additions correcting previous information which I can't check but appear not to be a patent nonsense. Anyway, the are written in the parenthetical polemics style
(This is not true, as german aviation engines were of the direct fuel injection type and used emergency methanol-water and nitrous-oxide injection ...
(this historical "issue" is based on a very common misapprehension about wartime fuel octane numbers. ...
As someone has already pointed out ...

so it would need proper wikification/rewrite anyway. --Malyctenar 15:21, 15 Feb 2005 (UTC)

Units

Could we please have this in SI units instead of 40 hogsheads to the rod units?

As long as the article has that weird name, the weird units look pretty normal to me! The problem is, the people who use those units don't understand them, and the people who don't use those units don't understand them either. So nobody can figure out how to convert them to SI units. Okay, maybe a couple of us could; I've got that hodsheads to the rod stuff down pat, 40.00 hogsheads to the rod is 1.897 m², round off that result according to how precise your "40" is. (One problem, of course, is that people don't use the SI units for fuel consumption or fuel economy; a typical automobile fuel consumption is in the 50 to 100 µm² range, however, so 40 hogsheads to the rod takes an enormous amount of fuel.) Gene Nygaard 09:07, 10 Apr 2005 (UTC)
BTW, that means, of course, that Grandpa Simpson's vehicle would probably work fine if he had a two square meter (in cross-section) trough of fuel along the road from which he could suck up his fuel. Gene Nygaard 09:20, 10 Apr 2005 (UTC)


Odd choice...

Why does it have this in the overview paragraph? "The United States use 360 million US liquid gallons (1.36 billion litres) of gasoline each day."

It seems as though it has been stuck in there as a quick shot against the US. I'm canadian, but i think it maked the entire paragraph flow oddly. any other opinions? SECProto 19:28, May 29, 2005 (UTC)

It does appear awkward, a better value would be the maount used in the world perahps with a couple of examples of vey high and low (per capita?) users. I suspect it was in there as an exmaple when the article was first written without an international flavour. GraemeLeggett 20:30, 29 May 2005 (UTC)
Good idea. - Omegatron 20:40, May 29, 2005 (UTC)

Octane of gasoline

The acticle overall is not that clear re octane rating for gasoline. In the US what you see on the pump when is says "87 octane" is actually not the RON (Research Octane Number) but an average of the RON and the MON (Motor Octane Number). Typical gasoline has a difference (called the sensitivity) between RON and MON of around 10: so in theUSA 87 octane is typically 92 RON, 82 MON.

Elsewhere in the world (gEurpoe, Asia, Aust: not sure about other places such as Latin America) what is normally quoted is just the RON (there will often be a separte specification for MON, but the general public does not tend to worry about it).

Question is: is this all too techy for wikipedia or should I go ahead and revise.

Also: re the debate re petrol and gasoline: within the industry people refer to "gasoline" all over the world: but the general public uses petrol in english speaking countries outside Nth America. The term Mogas, for Motor Gasoline (to distinguish from Avgas (Aviation gasoline) is also common everywhere). Another term is Motor Spirit, or Spirit for short. Once again...too much detail???

--GPoss 10:21, Jul 22, 2004 (UTC)