Cradle to Gate
Identity ID
3cd48476-d765-4a28-bd6c-cec1762e0a37
Materials
Associated ID
069aedba-d05c-402f-a618-180570ba3d08
Included activities starts
Included activities ends
Description
Polyethylene resin is cylindrical in shape, with a moisture content <=0. 0.05% (wt), mainly used for agricultural films, linings, and blends; this dataset includes primary raw materials, auxiliary materials, and energy consumption from the production process, as well as atmospheric emissions and wastewater. Infrastructure such as production equipment manufacturing and facility construction is not included within the system boundary of the dataset; the life cycle inventory is compiled from multiple data sources; the polyethylene plant employs a low-pressure gas-phase polymerization process, and the production units mainly include raw material purification and degassing, additive preparation, catalyst preparation, polymerization reaction, resin degassing and off-gas recovery, extrusion granulation, and product packaging units.
Activity Description
The production units of a polyethylene plant mainly include raw material purification and raw material degassing unit, additive unit, catalyst unit, polymerization reaction unit, resin degassing and off-gas recovery unit, extrusion granulation unit, product packaging unit, etc., with waste treatment included.
Process Description
Polyethylene resin is an odorless, tasteless, non-toxic, matte-surfaced, milky-white, wax-like granular material with a moisture content of ≤0.05% (wt). It is insoluble in most organic solvents and slightly soluble in hot toluene, acetic acid, etc. It is primarily used in agricultural films, liners, and blends.
Time period
2016
2026
Geography
China
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
The reaction mechanism of the low-pressure gas-phase polymerization process belongs to ion coordination catalytic polymerization. Ethylene can polymerize under low pressure due to the use of a highly efficient catalyst. After complexation, the catalyst forms a complex with high activity, sufficient to initiate the chain polymerization reaction of ethylene. 1-Butene is used as a comonomer, primarily to improve the polymer's properties. Isopentane (ICA) acts as an induced condensing agent to regulate the reaction temperature and does not participate in the reaction itself. Hydrogen is mainly used to control the molecular weight of the polymer. The primary equation for the polymerization reaction is: nH2C=CH2 -> [CH2-CH2]n.