European production sites and capcities in kilotonnes for the year

Applied processes and techniques in the production of polyvinyl chloride 

PVC is produced by the pol5Tnerisation of vinyl chloride monomer (VCM), which in turn is produced by the thermal cracking of ethylene dichloride (EDC). The chlorine used in the manufacture of EDC is derived from common salt (NaCl) by electrolysis, so 43 % by weight of PVC originates from crude oil. 

Various trace impurities do occur in the vinyl chloride, a number of these such as 1.3 butadiene and monovinyl acetylene can have adverse effects upon the polymerisation kinetics even at very low levels (mg per kg) and thus must be stringently controlled. Any imreactive liquid having a significantly higher boiling point than vinyl chloride, such as EDC, and remaining in the VCM will be foimd in the aqueous effluent, as measures designed to remove VCM will fail to remove them. 

For both emulsion and suspension processes, the VCM gas is polymerised in an aqueous medium. 

Polymerisation reactions are exothermic, thus the reactors must be equipped with cooling facilities. The pressure in the reactor is usually in the range of 0.4 - 1.2 MPa and the reaction temperature is in the range of 35 - 70 °C. At the end of the reaction, 85 - 95 % of the VCM is converted into PVC. 

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Table 5.2 European production sites and capcities in kilotonnes for the year 1999...

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