From oil and gas to polymers

摘要

Plastics are found in many forms in a wide array of everyday products and items, including automobiles, building materials, packaging, films, fibers, personal care products and cosmetics, and medical supplies. Over 90% of all plastics are derived from petroleum. To get from feedstock to plastic, high-technology processes break hydrocarbons down into simple molecules called monomers and then assemble them into polymers such as polyethylene, polypropylene and polystyrene. Plastics are essential in a number of fields. They lighten vehicles and airplanes, insulate buildings efficiently, extend the life of water and gas pipes, protect and conserve food, store data and more. Yet only a tiny percentage, about 4%, of world oil production goes into making polymers. However naphtha, a byproduct of crude oil distillation during refining, remains the bedrock of most commodity chemical processes. The most common method for obtaining olefins - ethylene, propylene, butadiene etc.- is cracking the molecules in a steam cracker. Aromatic compounds such as benzene and styrene are produced by catalytic reforming or similar processes.