Cradle to Gate
Identity ID
816cb85f-0b9a-4743-b0cf-9b8a12a159b8
Materials
Associated ID
b93d4e6c-9418-4f52-8317-33b87b505efc
Included activities starts
Included activities ends
Description
PS resin is widely used in household appliances, automobiles, home utensils, packaging containers, and industrial components; the dataset includes key raw and auxiliary materials, energy consumption, atmospheric emissions, and waste generated during the production process, but does not include infrastructure such as manufacturing of production equipment and construction of factory buildings within its system boundary; the life cycle inventory is compiled from multiple data sources; the polystyrene production process employs continuous bulk polymerization, with main production steps including mixing, pre-polymerization, polymerization, hydrocarbon removal, dehydration, storage, and pelletizing and packaging, as well as three auxiliary systems: vacuum system, hot oil/cooling oil system, and cooling water/chilled water system.
Activity Description
The polystyrene production process adopts a continuous bulk polymerization method. The main process includes units such as mixing, pre-polymerization, polymerization, dehydrocarbonization, dehydration, storage, granulation and packaging, as well as three auxiliary systems: vacuum system, hot oil/cooling oil system, and cooling water/chilled water system.
Process Description
Polystyrene (PS) includes general-purpose polystyrene (GPPS), expanded polystyrene (EPS), high-impact polystyrene (HIPS), and syndiotactic polystyrene (SPS). Polystyrene resin is a colorless and transparent, white, inelastic, odorless, tasteless, and non-toxic thermoplastic resin. It possesses characteristics such as transparency, electrical insulation, and surface gloss, exhibits good processability, and is suitable for downstream processing methods such as extrusion molding. PS resin is widely used in home appliances, automotive components, household goods, packaging containers, and industrial parts, making it one of the most popular plastic materials today.
Time period
2019
2026
Geography
China
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
1. Pre-polymerization unit: Before the material enters the process, the inhibitor contained in styrene is removed. Then, it is mixed with recovered styrene and recycled solvent (diluent) ethylbenzene at a certain ratio. After preheating and filtration to remove insoluble rubber or other impurities, the mixture enters the pre-polymerization reactor to initiate the polymerization reaction, with a residence time of 2. 5 to 4 hours.
2. Polymerization unit: The material exiting the prepolymerization reactor is pumped into reactor R1, where the heat generated from the polymerization reaction of styrene monomer (SM) into polymer is removed through internal cooling oil circulation coils and agitators. The conversion rate in reactor R1 is approximately 30--40%. The material is then pumped from the bottom of R1 to reactor R2, and subsequently transferred to reactor R3. In R3, the SM polymerization conversion rate reaches approximately 70%. The reaction temperatures of R1, R2, and R3 reactors are controlled differently according to their respective specifications. 3. Devolatilization Unit: The polymer is pumped out from the bottom of reactor R3 and rapidly heated to 230--240 °C via a devolatilization preheater, increasing the styrene monomer (SM) polymerization conversion to 99.7 %. The melt then enters devolatilizer DV1, where a vacuum pump removes unreacted residual SM monomer, which is sent to the monomer recovery section. The polymer is pumped from the bottom of DV1 to DV2 devolatilizer for a second vacuum stage, further removing residual SM monomer. Subsequently, the polymer is pumped to the pelletizing section.