Producing Vinyl Chloride

Ethylene and chlorine are combined to form a liquid, ethylene dichloride (i) which is then heated to give vinyl chloride (ii) which is then distilled off and gives hydrogen chloride gas;

H₂C=CH₂ + ClH₂C-CH₂Cl H₂C=CHCl + HCl

                                  (i)                              (ii)

Side reactions also occur to form organochlorine compounds some of which are collected as they have a commercial use. The remaining by-products are burnt to reclaim hydrogen chloride, which can be recycled and reacted with more ethylene to form new ethylene dichloride.

Vinyl chloride gas is less harmful than chlorine however a liver cancer called angiosarcoma has been linked with people who worked with vinyl chloride. Workers exposed to it are now protected and leaks and losses of vinyl chloride gas in plants are reduced to an absolute minimum and residual traces in the product PVC are removed as far as possible. These improvements ensure that the general public is at no risk at all from this chemical.