Phenol and acetone: Production route
The cumene trick that yields two products at once
What this tab covers How it is made: the main production routes or, for product families, the main product types and technologies, compared on share of supply, inputs per tonne, plant scale, yield, co-products and unit cost.Almost all phenol is made by the cumene (Hock) process, which links phenol to acetone and to benzene and propylene prices. Older and niche routes oxidise toluene via benzoic acid. Direct benzene oxidation has been tried but is not significant. Because the acetone ratio is fixed, plant economics depend on finding outlets for acetone, which is why many plants integrate into BPA, MMA or isopropanol.
Routes compared
| Route | Share of supply | Inputs per tonne | Typical scale | Yield | Co-products | Unit cost |
|---|---|---|---|---|---|---|
| Cumene (Hock) process | about 95% (indicative) | about 1.33 t cumene (0.87 t benzene and 0.47 t propylene) per t phenol (indicative) | 200-700 kt/yr phenol; Gladbeck 650 kt/yr total product (S&P Global) | about 0.62 t acetone per t phenol | acetone, alpha-methylstyrene, acetophenone | feed about 0.87 x benzene + 0.47 x propylene, less acetone credit, plus about $150-200/t conversion (indicative) |
| Toluene oxidation via benzoic acid | about 3% (indicative) | about 1.1-1.2 t toluene per t phenol (indicative) | small | lower than cumene | benzoic acid | not published |
| Bio-based and lignin-derived phenols | below 1% (indicative) | not published | pilot | mixed phenols | varies | not published |
How each route works
Cumene (Hock) processBenzene is alkylated with propylene to cumene, air-oxidised to cumene hydroperoxide and cleaved with acid into phenol and acetone. Licensors include KBR/Mitsui, UOP/Sunoco and Lummus/Versalis. Units are often integrated with BPA.
Mature and scalable; locks producer into acetone market.
S&P Global, 2025; indicative Toluene oxidation via benzoic acidToluene is oxidised to benzoic acid, then oxidatively decarboxylated to phenol. No acetone co-product. Used at a few sites.
Avoids acetone; costly at scale.
indicative Bio-based and lignin-derived phenolsPhenols are recovered from lignin or biomass pyrolysis oil. Mass-balance bio-cumene routes also exist.
Lower fossil carbon, but mixed products and small scale.
indicative Unit economics are indicative ranges from the sources named; costs move with feedstock and energy prices, plant size and region.