Color of oil distillates
Name: james d miks
Why is petroleum jelly not black, like asphalt, tar and other substances?
The answer is in your subject line: it's a distillate. When crude oil
is distilled, the gases are collected at different points along the
column. The purest distillates are collected at the very top, I believe.
What's left in the bottom of the pot is the black junky high molecular
weight stuff. Petroleum jelly is actually petrolatum, and according to
The Merck: A "purified mixture of semisolid hydrocarbons, chiefly of the
methane series of the general formula CnH2n+2. Actually, petrolatum is
a colloidal system of nonstraight-chain solid hydrocarbons and high-boiling
liquid hydrocarbons, in which most of the liquid hydrocarbons are held
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Update: June 2012