Styrene
The monomer for polystyrene, ABS and synthetic rubber, made from benzene and ethylene; a market reshaped by China's capacity surge.
Commodity chemicals · Aromatics · No. 29
- Single chemical
- Feedstock: Oil, gas or coal
- about 35 Mt a year of demand (2024, indicative, industry estimates)
- 2.8 t CO₂e per t
- HS 290250
China more than doubled its styrene capacity in five years and turned from the world's biggest buyer into a seller.
Chart: Illustration: Styrene
Where it comes from
Chart: Map of where it comes from
Benzene and ethylene are joined into ethylbenzene, then superheated steam at about 600 C strips off hydrogen. About a seventh comes as a by-product of propylene oxide plants.
Three things to know
- China's styrene capacity climbed from 9 Mt a year in 2019 to 22.6 Mt in 2024, flipping it from top importer to net exporter.
- European plants need a styrene-benzene spread of $200-250 a tonne; it sank to $71.50 in November 2023 and closures followed.
- Styrene polymerises by itself if it gets warm, which is why the 2020 Visakhapatnam vapour leak killed 12 people.
The journey
- 1 Benzene, ethylene0.79 t benzene, 0.28 t ethylene
- 2 EthylbenzeneZeolite alkylation, over 99% selective
- 3 DehydrogenationSteam and iron oxide at 600 C
- 4 Styrene monomerInhibited liquid, kept below about 25 C
- 5 PolymersPolystyrene, EPS, ABS, SBR tyre rubber