Propylene Oxide (PO)

Propylene Oxide (PO)

Propylene oxide (PO) is a colorless, low-boiling, and highly volatile liquid. It is highly flammable and reactive. There are currently several large-scale processes worldwide to make propylene oxide—the chlorohydrin process, propylene oxide/styrene monomer (PO/SM), propylene oxide/tert-butyl alcohol (PO/TBA), hydrogen peroxide to propylene oxide (HPPO)—but only one, the chlorohydrin process, consumes chlorine. In the chlorohydrin process, propylene is reacted with hypochlorous acid (made from chlorine) to make propylene chlorohydrin, which is then subsequently reacted with sodium or calcium hydroxide to make PO.