Purified terephthalic acid

Activity Purified terephthalic acid by air oxidation of p-xylene in acetic acid and hydropurification, GLO: the inventory of 1 kilogram of its reference product, attributional, cut-off.

Calculation maturity: not assessed Design maturity: Concept (research)Not independently reviewedterephthalic-acid-1:pta-px-air-oxidation:product:terephthalic-acidPreliminaryReport a problem with this dataset

Research outputAn inventory from a research design at the design maturity its process states, not verified plant data: check its calculation maturity and review status before use. Background activities are referenced by name only; no background data is included. All caveats

What it is

Per 1 t of purified terephthalic acid (PTA), gate-to-gate. p-Xylene is oxidised with air in acetic acid over a cobalt-manganese-bromide catalyst; the crude acid is hydrogenated over palladium and recrystallised from water. Feeds from a patent's figures for conventional plants, electricity from one EU plant's estimate, steam from the IEA's best-practice value for PTA, vent emissions from US EPA AP-42.

Reference product: 1 kilogram of Purified terephthalic acid
Chemical: terephthalic-acid
CAS: 100-21-0
Code: terephthalic-acid-1:pta-px-air-oxidation:product:terephthalic-acid
Dataset: pta-px-air-oxidation version 0.1.0 · UUID 680c1593-66e4-599a-bbc0-6cacce79cbfa
Activity UUID: not available (the library assigns none; use the code)
Database: cheme-as-code-atlas-preview-a3c52e4 (version preview-a3c52e4)
Process: Purified terephthalic acid by air oxidation of p-xylene in acetic acid and hydropurification
Geography: GLO · background inputs with a site rule link at the user's site location (default DE)
Time period: 2015 · valid until 2021
Technology: continuous liquid-phase air oxidation in acetic acid with Co/Mn/Br catalyst (Amoco, Mid-Century type) and catalytic hydropurification; the DMT route and oxygen-based oxidation are not modelled · level current
Boundary: gate-to-gate: oxidation, crystallisation, filtration and drying of crude TPA, solvent and catalyst recovery, hydropurification, PTA crystallisation and drying, thermal oxidation of the vents; steam and power from outside
Classification: ISIC Rev.4 2011 (taxonomy/families.yaml (ISIC Rev.4) of the process's families)
System model: attributional, cut-off (docs/system-model.md, methodology 1.1.0)
Allocation: mass, 100 % of the dataset to this product (rule single-output, from default)
one product: nothing to allocate
Rights: CC-BY-4.0

Exchanges per 1 kilogram of Purified terephthalic acid

As exported: allocated and scaled to the reference product. Provenance: 7 given, 1 assumed, 5 calculated. Pedigree scores (1 best, 5 worst): reliability, completeness, temporal correlation, geographical correlation, further technological correlation.

Preliminary5 exchanges are not yet linked to a background dataset. They count no burden, so the inventory is incomplete: do not read a result from it as complete.

Input	Amount	Unit	Provenance	Pedigree	Linked to
p-Xylene feed:p-xylene CN105001073A (CNPC and China Kunlun Contracting and Engineering Corp., published 2015-10-28), description, background on the conventional process of a 1.2 Mt/a PTA plant (machine translation, Google Patents); compare the stoichiometric 639.1 kg/t (C8H10 + 3 O2 -> C8H6O4 + 2 H2O)	0.656	kilogram	given	3 4 4 3 3	unlinked unlinked, no technosphere mapping: no mapping (chemical 'p-xylene'); add it to lci/mappings.yaml technosphere or to the process's lca/mappings.yaml exchanges
Acetic acid (solvent make-up) feed:acetic-acid CN105001073A (CNPC and China Kunlun Contracting and Engineering Corp., published 2015-10-28), description, background on the conventional process of a 1.2 Mt/a PTA plant (machine translation, Google Patents); burnt in the oxidation or lost as vent VOC (model below)	0.039	kilogram	given	3 4 4 3 3	Atlas (pinned): Acetic acid by low-water iridium methanol carbonylation (60 t/h glacial acid, concept) (Glacial acetic acid to storage, GLO) compatible: grade the input names acetic-acid only; acetic-acid (Glacial acetic acid to storage) is taken; unit kilogram; system model cutoff (one database); allocation none (single-output); boundary plant gate (pinned): no distribution or losses; the consumer's dataset counts its delivery
Demineralised water to the process feed:water CN105001073A (CNPC and China Kunlun Contracting and Engineering Corp., published 2015-10-28), description, background on the conventional process of a 1.2 Mt/a PTA plant (machine translation, Google Patents)	2.6	kilogram	given	3 4 4 3 3	market for water, deionised (water, deionised, RoW) in your background (default ecoinvent-3.11-cutoff)
Electricity feed:electricity Tran, A. and West, K.J. (2021) Decarbonisation options for the Dutch bottle-grade PET industry. PBL and TNO (MIDDEN), PBL publication 4617, Table 3, p. 17 (0.346 GJ/t at 3.6 GJ/MWh); the site has an off-gas expander and a gas-turbine CHP, so the figure may be net of the expander's power. The plant is Eastman-based (GPT) with post-oxidation and no hydrogenation step in the report, so it is not the hydropurified route modelled here electricity	0.09611	kilowatt hour	given	3 4 4 3 4	market for electricity, medium voltage (electricity, medium voltage, DE, site location) in your background (default ecoinvent-3.11-cutoff)
Steam, as heat delivered feed:steam IEA Information Paper (Saygin et al. 2009), Table 1, p. 15 (best practice for PTA, 2.6 GJ/t of steam in final energy terms, after Meyers 2005; at 3.6 GJ/MWh); the route is not named, and covering the hydropurification is ASSUMED. Compare 0.7 to 1.0 t steam per t in the patent CN105001073A for conventional hydropurified plants (pressure not stated) and the MIDDEN estimate of 0.981 GJ/t for an Eastman-based plant without hydrogenation	0.7222	kilowatt hour	given	3 4 4 3 4	Atlas: heat from steam, per kWh (Atlas unit proxy) (heat from steam, by energy, GLO)
Cobalt oxidation catalyst (make-up) input:cobalt-catalyst CN105001073A (CNPC and China Kunlun Contracting and Engineering Corp., published 2015-10-28), description, embodiment: the conventional process at the same site (machine translation, Google Patents); mass outside the element balance	4e-5	kilogram	given	3 4 4 3 3	unlinked unlinked, no technosphere mapping: no mapping (no chemical slug or factor id); add it to lci/mappings.yaml technosphere or to the process's lca/mappings.yaml exchanges
Manganese oxidation catalyst (make-up) input:manganese-catalyst CN105001073A (CNPC and China Kunlun Contracting and Engineering Corp., published 2015-10-28), description, disadvantage (4) of the conventional process (machine translation, Google Patents); the residue loss taken as the make-up (ASSUMED); mass outside the element balance	3e-5	kilogram	assumed	4 4 4 4 4	unlinked unlinked, no technosphere mapping: no mapping (no chemical slug or factor id); add it to lci/mappings.yaml technosphere or to the process's lca/mappings.yaml exchanges
Organic residue and dissolved by-products (benzoic, p-toluic and other acids) output:residue the p-xylene lost to the oxidation residue, the detention-pond solids and the purification mother liquor (CN105001073A), modelled as p-toluic acid, PX + 1.5 O2 -> C8H8O2 + H2O (ASSUMED; the LVOC BREF, section 2.1.2.3.8, names p-toluic, benzoic and other organic acids)	0.006156	kilogram	calculated	4 4 4 4 4	unlinked unlinked, no technosphere mapping: no mapping (no chemical slug or factor id); add it to lci/mappings.yaml technosphere or to the process's lca/mappings.yaml exchanges
Effluent to wastewater treatment output:wastewater the demineralised water plus the reaction and combustion water, all ASSUMED to leave as effluent (vent humidity neglected); compare about 3.0 t/t, the patent's 3.6 Mt/a of sewage for 1.2 Mt/a (whole site)	2.851	kilogram	calculated	4 4 4 4 4	Atlas (plant): wastewater to treatment, per kg (Atlas unit proxy) (wastewater, by mass, GLO) compatible: grade the input names wastewater only; wastewater (Wastewater treated) is taken; unit kilogram; system model cutoff (one database); allocation mass (single-output); boundary plant gate of a site utility: no utility market yet (docs/markets.md)

Elementary flows

Flow	Direction	Compartment	Amount	Unit	Provenance	Pedigree
Carbon dioxide, fossil 349b29d1-3e58-4c66-98b9-9d1a076efd2e	emission	air	0.09535	kilogram	calculated	4 4 4 4 4
Carbon monoxide, fossil ba2f3f82-c93a-47a5-822a-37ec97495275	emission	air	1.9e-4	kilogram	calculated	4 4 5 4 4
NMVOC, non-methane volatile organic compounds d3260d0e-8203-4cbb-a45a-6a13131a5108	emission	air	1.98e-4	kilogram	calculated	4 4 5 4 4
Terephthalic acid dust from the product transfer vent emission:PM unlinked unlinked, no biosphere mapping: emission of PM (literature) has no biosphere3 flow identity and is not in lci/mappings.yaml biosphere	emission	not linked	7e-4	kilogram	given	4 4 5 4 4

Where these numbers come from: each exchange names its source above; the dataset is processes/terephthalic-acid-1/lca/datasets/pta-px-air-oxidation.yaml in library version a3c52e4.

Used by

Polyethylene terephthalate resin, bottle grade (melt phase and SSP) pet-1:pet-pta-continuous-ssp:product:pet

How good it is

Review: Not reviewed: no LCI review record yet
Data quality: not available
Mass and carbon closure: Not available: a hand-written dataset: no lca/manifest.json records its balance
Change report: Not available: this build has no change report against an earlier release.

KPI benchmark positions

KPI	Value	Reference range	Position
Terephthalic acid per p-xylene fed, as a share of the stoichiometric maximum	– %	98.3 to 98.9 % Tran, A. and West, K.J. (2021) Decarbonisation options for the Dutch bottle-grade PET industry. PBL Netherlands Environmental Assessment Agency and TNO (MIDDEN), PBL publication 4617 (government)	not evaluated
Acetic acid consumption per t of purified terephthalic acid	– t/t	0.04 to 0.09 t/t Karali, N., Khanna, N., Shah, N. (2024) Climate Impact of Primary Plastic Production. Lawrence Berkeley National Laboratory, LBNL-2001585 (government)	not evaluated
Electricity and steam per t of purified terephthalic acid	– GJ/t	5.3 to 9.7 GJ/t Karali, N., Khanna, N., Shah, N. (2024) Climate Impact of Primary Plastic Production. Lawrence Berkeley National Laboratory, LBNL-2001585 (government)	not evaluated

How to use it

Downloads

cheme-as-code-atlas-preview-a3c52e4.xlsx · bw2io ExcelImporter workbook (bw2io 0.9 Excel layout) · the whole database
code terephthalic-acid-1:pta-px-air-oxidation:product:terephthalic-acid
cheme-as-code-atlas-preview-a3c52e4-olca-jsonld.zip · openLCA JSON-LD (olca-schema) (2) · the whole database
process 680c1593-66e4-599a-bbc0-6cacce79cbfa (processes/680c1593-66e4-599a-bbc0-6cacce79cbfa.json)
cheme-as-code-atlas-preview-a3c52e4-multifunctional.json · Brightway 2.5 multifunctional database (JSON, for the multifunctional package) (cheme-as-code/lci-multifunctional/v1) · the whole database
code terephthalic-acid-1:pta-px-air-oxidation:product:terephthalic-acid
cheme_as_code_lci-0.1.0-py3-none-any.whl · the installer

A file with this activity alone is not available: each file above is the whole database, and the line under it says how to find this activity there.

import bw2data as bd
from cheme_as_code_lci import install

bd.projects.set_current("my-project")   # holds your licensed background + biosphere3
install("cheme-as-code-atlas-preview-a3c52e4.xlsx", background="ecoinvent-3.11-cutoff", location="DE")
activity = bd.get_activity(("cheme-as-code-atlas-preview-a3c52e4", "terephthalic-acid-1:pta-px-air-oxidation:product:terephthalic-acid"))

While any exchange of the database has no mapping, install() writes nothing and only lists the unlinked exchanges. So the last line finds no activity until the gaps are mapped: the download section gives the ways to use the database now.

How to cite

Purified terephthalic acid, from Purified terephthalic acid by air oxidation of p-xylene in acetic acid and hydropurification (dataset pta-px-air-oxidation 0.1.0), ChemE-as-Code Process Atlas LCI database preview-a3c52e4, activity terephthalic-acid-1:pta-px-air-oxidation:product:terephthalic-acid. Cite the Process Atlas paper (in preparation, 2026), by Artur M. Schweidtmann and Jana M. Weber, and the ChemE-as-Code Process Atlas LCI database version preview-a3c52e4.

DOI: none yet (the Process Atlas paper is in preparation)

For the data, cite the Process Atlas paper; for the platform that builds and checks it, the ChemE-as-Code paper.

Schweidtmann, A. M. & Weber, J. M. (2026, in preparation). Process Atlas: an open, git-native, reproducible library and life cycle inventory of chemical processes (working title).

BibTeX

@unpublished{schweidtmann_process_atlas,
  author = {Schweidtmann, Artur M. and Weber, Jana M.},
  title = {{Process Atlas: an open, git-native, reproducible library and life cycle inventory of chemical processes (working title)}},
  year = {2026},
  url = {https://atlas.cheme-as-code.org},
  note = {in preparation}
}

Schweidtmann, A. M. (2026). ChemE-as-Code: An Open-Source Platform for Agentic AI in Chemical Engineering. arXiv:2611.07947. https://doi.org/10.48550/arXiv.2611.07947

BibTeX

@misc{schweidtmann_cheme_as_code,
  author = {Schweidtmann, Artur M.},
  title = {{ChemE-as-Code: An Open-Source Platform for Agentic AI in Chemical Engineering}},
  year = {2026},
  eprint = {2611.07947},
  archivePrefix = {arXiv},
  doi = {10.48550/arXiv.2611.07947},
  url = {https://arxiv.org/abs/2611.07947}
}