Location: RER - Europe
The dataset represents the production mix of commercial S-PVC production technologies
Polyvinyl chloride (PVC) is manufactured by polymerisation of vinyl chloride monomer (VCM). Polymerisation of PVC is an exothermic reaction. The pressure in the reactor is usually in the range of 0.4 – 1.2 MPa and the reaction temperature is between 35 – 70°C. During the polymerisation reaction 85 – 97% of the VCM is converted into PVC. Residual VCM is removed by stripping the polymer suspension or latex. The unreacted monomer is recovered, liquefied, and returned to polymerisation
For the polymerisation process certain process chemicals are required. Surfactants, emulsifiers and protective colloids are used to prepare and stabilize the dispersion of monomer and PVC in process water (typically around 1 kg/t VCM in suspension and around 10-20 kg/t in emulsion). Organic peroxides or peresters are used as initiators (typically 1 kg/t VCM) for the production of suspension and microsuspension PVC, while e.g. hindered phenols are used to stop the reaction (typically < 1 kg/t VCM). For the production of emulsion PVC inorganic peroxides are common.
PVC resin resulting from the suspension process (S-PVC) has a mean particle size of 50 – 200 μm. The essential differences between S-PVC grades result from the average length of polymer chains and from the porosity of the particles. Suspension PVC is always produced batch wise in a stirred vessel. The monomer is dispersed in demineralised water by the combination of mechanical stirring and surfactants. The polymerisation takes place inside the VCM droplets under the influence of VCM soluble initiators such as peresters, percarbonates, or peroxides.
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.