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values of ron and octane
- Subject: values of ron and octane
- From: juliemac57@hotmail.com (Julie Macfarlane)
- Date: Sun, 27 Apr 2003 00:00:15 +0000
Brian, you frighten me.
Julie Macfarlane
Menlo Park Research & Development
Internet Application Developer
www.menloparkrandd.com
www.montgomeryweb.org
Amsterdam NY
>From: <brian_wagner@sbcglobal.net>
>To: "Ron Pieper" <rapieper@yahoo.com>,"Josh20V"
><mkii@nycap.rr.com>,<scirocco-l@scirocco.org>
>Subject: Re: values of ron and octane
>Date: Sat, 26 Apr 2003 16:47:32 -0500
>
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> Gasoline & Octane Ratings
>
> How is gasoline made? What are octane ratings?
>
> Related Resources
> . Chemistry Glossary
> . Chemical Structures
> . Geochemistry
>
>
>
>
>
>
> Elsewhere on the Web
> . FAQ: Automotive Gasoline
> . American Petroleum Institute
> . How Car Engines Work
>
>
>
>
>
> Gasoline consists of a complex mixture of hydrocarbons. Most
>of
>these are alkanes with 4-10 carbon atoms per molecule. Smaller amounts of
>aromatic compounds are present. Alkenes and alkynes may also be present in
>gasoline.
>
> Gasoline is most often produced by the fractional distillation
>of petroleum, also known as crude oil (it is also produced from coal and
>oil
>shale). The crude oil is separated according to different boiling points
>into fractions. This fractional distillation process yields approximately
>250 mL of straight-run gasoline for each liter of crude oil. The yield of
>gasoline may be doubled by converting higher or lower boiling point
>fractions into hydrocarbons in the gasoline range. Two of the main
>processes
>used to perform this conversion are cracking and isomerization.
>
> In cracking, high molecular weight fractions and catalysts are
>heated to the point where the carbon-carbon bonds break. Products of the
>reaction include alkenes and alkanes of lower molecular weight than were
>present in the original fraction. The alkanes from the cracking reaction
>are
>added to the straight-run gasoline to increase the gasoline yield from the
>crude oil. An example of a cracking reaction is:
>
> alkane C13H28 (l) --> alkane C8H18 (l) + alkene C2H4 (g) +
>alkene C3H6 (g)
>
> In the isomerization process, straight chain alkanes are
>converted into branched chain isomers, which burn more efficiently. For
>example, pentane and a catalyst may react to yield 2-methylbutane and
>2,2-dimethylpropane. Also, some isomerization occurs during the cracking
>process, which increases the gasoline quality.
>
> In internal combustion engines, the compressed gasoline-air
>mixtures have a tendency to ignite prematurely rather than burning
>smoothly.
>This creates engine knock, a characteristic rattling or pinging sound in
>one
>or more cylinders. The octane number of gasoline is a measure of its
>resistance to knock. The octane number is determined by comparing the
>characteristics of a gasoline to isooctane (2,2,4-trimethylpentane) and
>heptane. Isooctane is assigned an octane number of 100. It is a highly
>branched compound that burns smoothly, with little knock. On the other
>hand,
>heptane is given an octane rating of zero. It is an unbranched compound and
>knocks badly.
>
> Straight-run gasoline has an octane number of about 70. In
>other
>words, straight-run gasoline has the same knocking properties as a mixture
>of 70% isooctane and 30% heptane. Cracking, isomerization, and other
>processes can be used to increase the octane rating of gasoline to about
>90.
>Anti-knock agents may be added to further increase the octane rating.
>Tetraethyl lead, Pb(C2H5)4, was one such agent, which was added to gas at
>the rate of up to 2.4 grams per gallon of gasoline. The switch to unleaded
>gasoline has required the addition of more expensive compounds, such as
>aromatics and highly branched alkanes, to maintain high octane numbers.
>
> Gasoline pumps typically post octane numbers as an average of
>two different values. Often you may see the octane rating quoted as
>(R+M)/2.
>One value is the research octane number (RON), which is determined with a
>test engine running at a low speed of 600 rpm. The other value is the motor
>octane number (MON), which is determined with a test engine running at a
>higher speed of 900 rpm. If, for example, a gasoline has an RON of 98 and a
>MON of 90, then the posted octane number would be the average of the two
>values or 94.
>
> High octane gasoline does not outperform regular octane
>gasoline
>in preventing engine deposits from forming, in removing them, or in
>cleaning
>the engine. Consumers should select the lowest octane grade at which the
>car's engine runs without knocking. Occasional light knocking or pinging
>won't harm the engine, and doesn't indicate a need for higher octane. On
>the
>other hand, a heavy or persistent knock may result in engine damage.
>
>
>
>----- Original Message -----
>From: "Ron Pieper" <rapieper@yahoo.com>
>To: "Josh20V" <mkii@nycap.rr.com>; <scirocco-l@scirocco.org>
>Sent: Saturday, April 26, 2003 3:56 PM
>Subject: Re: values of ron and octane
>
>
> > I am ron. I think I am valuable, but I am not related to anyone named
>octane levels. I never
> > 'did' anyone named octane either, not 87 times, nor 93, nor any.
>Nowhere,
>US or otherwise.
> >
> > Sorry, ya got the w-ron-g guy.
> >
> > Ron
> >
> > --- Josh20V <mkii@nycap.rr.com> wrote:
> > > Somebody care to explain the direct relation between ron and octane
>levels?
> > > What ron does 87/93/etc octane in the US have?
> >
> >
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