Propylene oxide (PO) is one of the most important chemical feedstocks for producing polyether polyol polymers such as polyurethane. Commercially, PO is manufactured by either chlorohydrin or co-production (Halcon) route. The chlorohydrin route generates chlorinated by-products, mainly dichloropropane and CaCl2. The co-production route is capital intensive and its economics is linked to the economic fortunes of the by-products, namely styrene or tert-butyl alcohol.