How pentane is made

It boils near 36 °C, close to body temperature, and that is exactly why foam makers trap it in plastic beads.

stations: 5
things upstream: 2
raw sources: 2
step from the ground: 1

The short version

This five-carbon hydrocarbon is already in crude oil and natural gas, so nothing has to be built. Gas plants and refineries separate it from heavier and lighter molecules by fractional distillation, then rectify it further. Most of its fame comes from foam, where it boils inside polystyrene beads and swells them up.

Strip liquids from gas

Raw natural gas is cooled so that heavier hydrocarbons condense. Pressure drops across a control valve flash the lightest ones away from a liquid called condensate, which holds propane, butane, pentane and hexane.

Goes in
Natural gas
Distill from crude

Refineries get the same molecules from fractional distillation of petroleum. A light cut comes off with a boiling range that takes in the five-carbon compounds.

Goes in
Crude oil
Rectify the cut

Repeated distillations narrow the stream down until five-carbon hydrocarbons dominate. The three isomers boil from about 9 to 36 °C, and the most branched boils lowest.
Rearrange some isomers

An acid catalyst turns part of the normal form into isopentane, valued in high-octane fuel. The straight-chain form alone rates just 62.
Send out for foam

Sealed tankers take it to chemical plants. There it soaks into polystyrene beads as a blowing agent, a job it took over from CFCs in the 1970s. Other shipments go to refrigerant blenders and geothermal power stations.

End of the linePentane Next it goes into styrofoam, foam cup.

Worth repeating

Polystyrene foams are 95 to 98 percent air.
Carl Schorlemmer discovered normal pentane in 1862 while analyzing products from the cannel coal mined in Wigan.
Pentane occurs in hop oil and in alcoholic drinks.