Propylene Oxide from Propylene and Hydrogen (Indirect Oxidation)

Product

Propylene Oxide. Propylene Oxide (PO) is a major commodity chemical. This highly reactive compound is starting material for several products, from polymers and solvents to industrial fluids. Commercially, Propylene Oxide is produced mainly by the so-called chlorohydrin process, based on the reaction of propylene and chlorine in the presence of water to produce propylene chlorohydrin, which is dehydrochlorinated with a base (caustic or lime). PO may also be produced on commercial scale by the oxidation of propylene by organic hydroperoxides – the so called indirect oxidation routes – yielding alcohols as by-product.

Raw Materials

Propylene. Propylene, the main raw material consumed, is a colorless gas at room temperature. It is a low-boiling, flammable, and highly volatile gas, with molecular formula C3H6. Propylene reacts vigorously with oxidizing materials. It may be mildly irritating to the nose, throat, and respiratory tract; propylene has low acute toxicity from inhalation. PG Propylene has been mainly produced as ethylene manufacturing co-product (via steam cracking of paraffinic hydrocarbons) and by-product of petroleum refining (separation from refinery gas). Most recently, amid a tight propylene market, new and novel lower-cost chemical processes for on-purpose propylene production have emerged.

Hydrogen. The hydrogen molecule, H2, is the normal state of pure hydrogen, even though hydrogen can be found in its atomic form under specific conditions. It is a very stable molecule, not usually reactive under normal conditions. Essentially, molecular hydrogen is produced industrially by three different methods: hydrocarbons steam reforming, hydrocarbons partial oxidation and water electrolysis. Hydrogen can also be obtained as a by-product recovered in processes such as the manufacture of styrene from ethylbenzene.