Procédé : PET
Nom technique : Polyethylene terephthalate, granulate, bottle grade {RER}| production | Cut-off, S - Copied from Ecoinvent U
Localisation : RER
Catégories : food
Unité : kg
Source : Agribalyse 3.2
Coût environnemental (points d'impact) : 569.79
AGRIBALYSE v3.2 dataset, 2024.
original ecoinvent name: Polyethylene terephthalate, granulate, bottle grade {RER}| polyethylene terephthalate production, granulate, bottle grade | Cut-off, S

The dataset represents the production mix of commercial bottle grade PET production technologies. PET production covered by this study is by esterification of ethylene glycol and terephthalic acid (PTA). The esterification process is carried out under moderate pressure (2.5-5.5 bar) and at high temperature (230-270 °C) whilst the water formed during the reaction is continuously removed via distillation. 

The monomers of PET production, purified terephthalic acid (PTA) and mono ethylene glycol (MEG) are polymerised in the liquid phase to produce amorphous PET. This form of the polymer is suitable for the production of fibres and film. Most bottle grade PET today is a copolyester slightly modified through addition of 1-2% Benzene-1,3-dicarboxylic acid (isophthalic acid, IPA) or 4(hydroxymethyl)cyclohexyl-methanol (cyclohexanedimethanol, CHDM) during polymerisation.

The first step of PET production is the esterification of PTA and MEG to bishydroxyethyl terepthalate (BHET) with water as a by-product at around 220-260 °C in the presence of an anti-mony catalyst (usually Sb2O3). Water forming from the esterification reaction is continuously removed by distillation. Formation of the undesired side product diethylene glycol is suppressed by maintaining low molar ratios of MEG:PTA (less than 2 or even 1.5). BHET is then sent to Pre-polycondensation in a second reactor under a vacuum and further to a melt polycondensation reactor at higher temperatures and still under vacuum. Vacuum is required to remove water and other side products and to drive the reaction equilibrium towards the polymer.

As melt polymerisation does not produce high molecular weight, a subsequent polymerisation step, solid state polymerisation (SSP) is required for bottle grade PET. During SSP the polymer chain lengths are increased by heat in the absence of oxygen and water, by means of either vacuum or purging with an inert gas to drive off the by-products of reactions. The reaction is driven by temperature, pressure, and the diffusion of by-products from the interior of the pellet to the surface. The product of SSP is a partially crystalline resin that can be used to produce bottles via injection moulding and stretch blow moulding.

Production volume: 3400000000 kg
Included activities start: Acitivity starts with PTA entering the polymerisation plant. Both amorphous and bottle grade PET produciton are included. Energy supply is included in terms of heat production inside the battery limits of the plant. Steam and electricity supply is outside the activity.
Included activities end: Activity ends with polymer granulate leaving the factory.
Energy values: Undefined
Geography: The inventory is modelled for Europe
Technology level: Current
Technology: Coverage of production capacity in Europe: 85%
Start date: 01/01/2015
End date: 31/12/2022
Is data valid for entire period: True
Time period: Data was collected for the year 2015, processed in 2016 and published in 2017
Macro-economic scenario name: Business-as-Usual

Version: 6.3.0.0
Created: 9/19/2018 9:57:29 AM
Last edited: 1/10/2019 9:25:51 AM
Source: 4f3acb8f-af33-5b3c-a750-8176c10ad5f1_19bacec1-aff8-4398-a7bd-d125b48505b7.spold
UUID: 4f3acb8f-af33-5b3c-a750-8176c10ad5f1