PVC was first spotted as white gunk in a flask left in sunlight
In 1835 the French chemist Henri Victor Regnault left vinyl chloride sitting in the sun and later found a white solid at the bottom of the flask. It was polyvinyl chloride, now the stuff of pipes and tubing. Four years later Eduard Simon stumbled on polystyrene while distilling storax, a plant resin.
Petrochemicals are the chemicals refined out of petroleum, though some also come from coal, natural gas or crops such as maize and sugar cane. Two families dominate. Olefins, chiefly ethylene and propylene, are made by cracking: refineries break down oil fractions with catalysts, and chemical plants blast natural gas liquids such as ethane with steam. Aromatics, above all benzene, toluene and the xylenes, known together as BTX, come from reforming naphtha. In 2019 the world made about 190 million tonnes of ethylene and 120 million of propylene, alongside roughly 70 million tonnes of aromatics.
Those few molecules fan out into a huge range of goods. Ethylene becomes polyethylene, antifreeze and even a ripening agent for fruit. Propylene yields rubbing alcohol and aircraft deicer. Butadiene goes into synthetic rubber, benzene into dyes and detergents, and xylene into plastic bottles and synthetic fibres. A splash of 1-hexene mixed into ethylene makes a more flexible polyethylene. A separate stream, synthesis gas, feeds methanol and the ammonia behind urea fertiliser.
The industry grew out of a run of inventions. William Henry Perkin made mauveine, the first synthetic dye, in 1856, and Leo Baekeland produced Bakelite from phenol and formaldehyde in 1909. Union Carbide opened the world's first petrochemical plant in West Virginia in 1920. Then came a burst of materials: Walter Bock's Buna-S rubber for tyres in 1929, polyethylene from Michael Perrin in 1935, Wallace Carothers's nylon in 1937, Otto Bayer's polyurethane in 1938 and Roy Plunkett's Teflon in 1941. Stephanie Kwolek added Kevlar in 1965.
Production is concentrated in a handful of giant clusters, among them Jubail and Yanbu in Saudi Arabia, the Texas and Louisiana coast, Rotterdam, Antwerp, Jamnagar and Singapore. Plants huddle together to share power stations, ports, pipelines and storage, and feed one another's raw materials. Teesside in northeast England alone turns out about half of Britain's petrochemicals and commodity chemicals.
Source: Petrochemical
