substance

Polyethylene

A polymer, recorded by the registry's polymer rule (docs/registry.md, Polymers): the formula is the repeat unit C2H4, which an ethylene copolymer with 1-butene or 1-hexene units shares, so the composition holds for HDPE, LDPE and LLDPE alike; the molar mass is that of the repeat unit, not of a chain (whose length has a distribution). The ChEBI id is the polymer poly(ethylene), which cross-references CAS 9002-88-4 and gives (C2H4)n (ChEBI via EBI OLS, 2026-11-05; CHEBI:60034 'polyethylene polymer' and CHEBI:53226 'polyethylene macromolecule' are related entries). No InChIKey or PubChem CID: the chemicals package (1.5.2) resolves CAS 9002-88-4 to the monomer ethene (VGGSQFUCUMXWEO-UHFFFAOYSA-N), so the entry is in tests/test_registry.py's CHEMICALS_PACKAGE_EXCEPTIONS, and PubChem's compound search finds no CID for it (PUG REST, 2026-11-05). Grades (HDPE, LDPE, LLDPE) are not split yet.

Formula: C2H4
CAS: 9002-88-4
ChEBI: CHEBI:53227

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Made by

High-density polyethylene by low-pressure polymerisation of ethylene (European average)Main productConcept · not reviewed

Used by

No process in the Atlas uses this yet.

When a process with this chemical is added to the library, it appears here.

Routes compared

One route in the Atlas makes Polyethylene: nothing to compare yet. A comparison appears when a second route is added.

Per 1 kg of Polyethylene: inventory from each route's LCI dataset, unallocated; footprints per the functional unit of their own LCA.

Route	Tier, design maturity, review status	Geography, year	Energy	Feedstocks	Key emissions	Footprint	Comparability
High-density polyethylene by low-pressure polymerisation of ethylene (European average)Ziegler or chromium-catalysed low-pressure polymerisation; the source averages slurry (loop and stirred-tank) and gas-phase plants, and the slurry-specific choices (isobutane diluent) are ASSUMED	Tier 1 (sourced conceptual)Design maturity: Concept (research)Not independently reviewedDataset review: unreviewed	RER, 2011	Electricity: 0.432 kWh Thermal energy (net), counted as steam heat delivered: 0.374 kWh	Ethylene, polymer grade: 1 kg 1-Butene, comonomer: 0.016 kg Hydrogen, chain-transfer agent: 0.00024 kg Diluent make-up (isobutane ASSUMED): 0.0059 kg Combustion oxygen, from ambient air: 0.0418 kg (free) Process water: 1.6 kg	CO2 from the flare or thermal oxidiser: 0.035 kg Water vapour from the burnt purge and vent gases: 0.0183 kg CO from the flare or thermal oxidiser: 0.000067 kg Methane: 0.0000013 kg Ethylene to air: 0.00026 kg NOx: 0.000012 kg SO2: 0.000000073 kg Particulates, PM10: 0.0000014 kg	no footprint	–

ISO 14044 requires a critical review (by a panel of interested parties, ISO/TS 14071) of a comparative assertion intended to be disclosed to the public. These routes are listed side by side for screening; a statement that one is better than another needs that review. None of these routes has had such a review.