Feed vinyl chloride monomer process

This process is shown schematically in Figure 7. The ethylene part of the feed reacts with chlorine in the liquid phase to produce 1,2-di-chloroethane (EDC) by a simple addition reaction, in the presence of a ferric chloride catalyst (9). Thermal dehydrochlorination, or cracking, of the intermediate EDC then produces the vinyl chloride monomer and by-product HC1 (1). Acetylene is still needed as the other part of the over-all feed, to react with this by-product HC1 and produce VCM as in the all-acetylene route. 

The vinylidene chloride (Mi)-vinyl chloride (M2) system is an example of a random copolymerization in which = 3.2, ri — 0.3, and r r2 — 1- Reasonably homogeneous copolymers with controlled concentrations of the less reactive component can be made in semibatch processes by controlling the monomer feed. In this case the more reactive ingredient, vinylidene chloride, is added intermittently or continuously in a proportional manner to a mixture to which all the vinyl chloride is charged initially. 

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