# Purified terephthalic acid: Production route

One process, licensed everywhere, from paraxylene to white powder

Source page: https://www.materialinsights.org/chemicals/pta/routes/

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 PEF**

Bio-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.

## Other sections

- [Summary](https://www.materialinsights.org/chemicals/pta/index.md)
- [Overview](https://www.materialinsights.org/chemicals/pta/overview/index.md)
- [Correlation](https://www.materialinsights.org/chemicals/pta/correlation/index.md)
- [Production](https://www.materialinsights.org/chemicals/pta/production/index.md)
- [Feedstocks](https://www.materialinsights.org/chemicals/pta/feedstocks/index.md)
- [Cycles](https://www.materialinsights.org/chemicals/pta/cycles/index.md)
- [Trading](https://www.materialinsights.org/chemicals/pta/trading/index.md)
- [Movement](https://www.materialinsights.org/chemicals/pta/movement/index.md)
- [Regulation](https://www.materialinsights.org/chemicals/pta/regulation/index.md)
- [Characteristics](https://www.materialinsights.org/chemicals/pta/characteristics/index.md)
- [Emissions](https://www.materialinsights.org/chemicals/pta/emissions/index.md)
- [Relationships](https://www.materialinsights.org/chemicals/pta/links/index.md)