Chemistry Reference
In-Depth Information
PROPYLENE (CH
3
CH
CH
2
)
Properties
Colorless, flammable gas boiling at
−
48°C (about
−
54°F). Burns with a yellow sooty flame, so it can
be substituted for propane in liquid petroleum gas
(LPG).
Commercial grades
Available in three grades: refinery (50-70%), chemical
(90-92%), and polymer (99%) grade. The remaining
percentage in each case is mainly propane. It is
shipped as a liquid in pipelines, tank cars, tank
trucks, and steel cylinders. Storage is as a liquid at
pressures of about 200 psi.
Uses
Used in the petroleum industry to make so-called
alkylate for improved octane gasoline. Large
quantities are polymerized to polypropylene for
carpeting, upholstery, ropes, and other uses. Used in
the chemical industry as a starting material for many
large-volume chemicals such as acetone,
acrylonitrile, and propylene oxide.
Manufacture
Made in exactly the same way ethylene is made, that
is, by cracking low-cost hydrocarbons. Plants that
produce propylene are always called ethylene plants
because that is the principal product.
Producers
BP Amoco, Chevron, DuPont, Exxon Mobil, Equistar,
Shell, Huntsman, Phillips, Dow, and others.
The production volume of propylene tracks that of ethylene because they
are simultaneously produced in the same plants. Usually, propylene sells for
a somewhat lower price than ethylene, but this occasionally varies when
derivative demands change. Prices for both stay relatively constant in the
25-30 cent/lb. range.
