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Formula for Heavy Paraffinic Base Oil ?

  1. Oct 20, 2006 #1
    Formula for "Heavy Paraffinic Base Oil"?

    Is there a chemical formula for "Heavy Paraffinic Base Oil"? (like the base oil in motor oil) Or is it made up of other compounds and that's why I can't find a formula for it.? If so than I need to give a full description of the chemical with a formula so what would you use to fully describe in detail "Heavy Paraffinic Base Oil" if you can't use a formula? In other words how would someone know exactly which chemical you mean?

  2. jcsd
  3. Oct 20, 2006 #2


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    You're talking about a "distillation cut," or boiling point range, C-H ratio (degree of saturation), and, maybe, melting point range. How many different compounds in the mix? Don't think anyone's ever tried for a "global" assay.
  4. Oct 20, 2006 #3
    A very large number of different hydrocarbons, most of which are chemically very similar; it's neither easy nor useful to identify them entirely. See for instance:


    It looks like motor oils are mixtures of hydrocarbons boiling above 400C, usually having >20 carbon atoms per molecule.
  5. Oct 20, 2006 #4
    Just to give you an idea of the scale of things, if you only consider the alkanes with n=20 carbons, there are http://www.research.att.com/projects/OEIS?Anum=A000602 [Broken] structural isomers! I'm not sure how many of these are actually present in crude oil, but I'm sure it's a very large number (especially after catalytic cracking.)
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