Purified terephthalic acid: Production route
One process, licensed everywhere, from paraxylene to white powder
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 PTA uses the Amoco (Mid-Century) process: liquid-phase air oxidation of paraxylene in acetic acid with a cobalt-manganese-bromide catalyst, followed by hydrogenation to remove impurities. Licensors include INVISTA (now Koch Technology Solutions), BP, Mitsubishi Chemical and Sinopec, with Chinese engineering firms now building 2.5-3 Mt/yr trains. A small share of polyester is still made from DMT. Medium-purity grades and bio-based alternatives are niche.
Routes compared
| Route | Share of supply | Inputs per tonne | Typical scale | Yield | Co-products | Unit cost |
|---|---|---|---|---|---|---|
| PX oxidation plus hydrogenation purification (PTA) | about 95% (indicative) | about 0.655-0.665 t PX, 0.03-0.05 t acetic acid consumed, small hydrogen, about 0.1-0.15 MWh power (indicative) | 1-3 Mt/yr per train; Shenghong Lianyungang 2.4 Mt/yr (Argus); new Chinese plants average 2.75 Mt (Tiger Brokers) | over 99% on PX (indicative) | off-gas CO2 and CO from acetic acid burn; methyl acetate; wastewater with high COD | processing cost about $60-100/t over PX in large Chinese plants (indicative); non-China producers need PX plus at least $100/t (S&P Global, Jan 2026) |
| Dimethyl terephthalate (DMT) | about 3% (indicative) | PX plus methanol | small | lower | methanol recycled | higher than PTA |
| Medium-purity or single-step processes (e.g. EPTA, QTA) | about 2% (indicative) | similar PX use | 1 Mt/yr class | similar | similar | lower capex (indicative) |
| Bio-based terephthalic acid or FDCA for PEF | below 0.1% (indicative) | not published | Avantium FDCA plant about 5 kt/yr (indicative) | n/a | n/a | well above fossil (indicative) |
How each route works
PX oxidation plus hydrogenation purification (PTA)PX and acetic acid with Co-Mn-Br catalyst are oxidised with compressed air. Crude TA is separated, redissolved in hot water and hydrogenated to convert 4-carboxybenzaldehyde, then crystallised. Energy is partly recovered from the exothermic oxidation.
Mature, huge scale; tight margins and large capex.
S&P Global Jan 2026; Argus Mar 2025; Tiger Brokers 2025; indicative Dimethyl terephthalate (DMT)PX is oxidised and esterified with methanol to DMT, then transesterified with MEG. Older route still used for some PBT and specialty polyesters.
Easier purification; less efficient.
indicative Medium-purity or single-step processes (e.g. EPTA, QTA)Process variants that skip or simplify hydrogenation and are suitable for some fibre grades.
Cheaper but limited grade range.
indicative Bio-based terephthalic acid or FDCA for PEFBio-PX or other bio-routes give bio-PTA; FDCA from sugars makes PEF, a different polyester (Avantium).
Lower fossil carbon; far from parity.
indicative Unit economics are indicative ranges from the sources named; costs move with feedstock and energy prices, plant size and region.