ethylene glycol production, UPR, ecoinvent 3.6, Undefined

Categories:
ISIC4 categories:
C:Manufacturing/20:Manufacture of chemicals and chemical products/201:Manufacture of basic chemicals, fertilizers and nitrogen compounds, plastics and synthetic rubber in primary forms/2011:Manufacture of basic chemicals
Location:
RER - Europe
Reference year: 1997 - 2000
Description

Location: RER - Europe
This Multi-Output inventory is based on literature sources that are based on actual plant throughputs and measurements. The oxidation of ethylene oxide leads to the production of 1 kg of three coproducts: ethylene glycol, diethylene glycol (DEG) and triethylene glycol (TEG). Raw materials, energy consumption and emissions are modelled with literature data. Infrastructure is included with a default value.
Undefined unit processes (UPRs) are the unlinked, multi-product activity datasets that form the basis for all of the system models available in the ecoinvent database. This is the way the datasets are obtained and entered into the database by the data providers. These activity datasets are useful for investigating the environmental impacts of a specific activity (gate-to-gate), without regard to its upstream or downstream impacts.

Technology

Ethylene is directly oxidized with air or oxygen in the presence of a catalyst to ethylene oxide (EO). The ethylene oxide is subsequently treated with water (hydrolyzed) and forms a variety of glycols, most notably mono ethylene glycol (MEG), di ethylene glycols (DEG) and tri ethylene glycols (TEG). About 40% of all European EO production is converted into glycols, globally the figure is about 70%. Usually, EO and MEG are produced together at integrated plants.
An ethylene oxide / water mixture is heated up to 190 - 200°C and pressurized to 14-22 bar. About 70 – 95% of the mixture consists of MEG, the rest primarily consisting of DEG and TEG. A yield for MEG of 67% is obtained. Poly-ethylene glycols are also formed, but can be controlled by using an excess of water. The usual configuration for glycols production is an integrated EO / EG plant.
Glycol products typically consist of 70 – 95% w/w of MEG, the primary co-product being DEG, some of which can further react to TEG. All of the EO feed is converted into MEG, DEG TEG as well as some heavy glycols, which may however be incinerated. 2 – 100 kg heavy glycols / ton EO can be produced.
C2H4 + 1/2 O2  C2H4O (1)
C2H4 O + H2O  HO-C2H4-OH (2)
HO-C2 H4-OH + C2H4O  HO- C2H4-O- C2H4-OH (3)
HO-C2 H4-O-C2H4-OH + C2H4O  HO- C2H4-O-C2H4-O-C2H4-OH (4)
(1) production of ethylene oxide
(2) production of MEG from EO and water
(3) production of DEG from EO and MEG
(4) production of TEG from EO and DEG

The water-glycol mixture is fed to multiple evaporators, where water is recovered and recycled. The water-free glycol mixture is separated by fractional distillation. Acids (e.g. 1% sulfuric acid) catalyse the hydration reaction and allow lower temperatures to be used

Based on the available figures for ethylene oxide production, it can be assumed that approximately 5 million tons of ethylene oxide were converted to glycols in Europe and the U.S. in 1997 (7 million tons of glycols based on the ration of molecular weights of MEG to EO). Further production capacity of at least 1.2 million tons is reported from Saudi Arabia, Kuwait and South Korea, giving a total of ca. 8.5 million tons of ethylene glycols production worldwide.
References:
IPPC Chemicals 2002. European Commission, Directorate General, Joint Research Center, “Reference Document on Best Available Techniques in the Large Volume Organic Chemical Industry”, February 2002

Wells 1999. G. Margaret Wells, “Handbook of Petrochemicals and Processes”, 2nd edition, Ashgate, 1999

Process type
Unit
Supported nomenclature
ecoinvent 3.6
LCI modeling approach
Before modeling
Multifunctional modeling
NONE
Format
ECOSPOLD2
Aggregation type
NOT_APPLICABLE
Data provider
ecoinvent
Review status
External
Cost
For sale
License

ecoinvent EULA

Contact
support@ecoinvent.org