Polyvinylchloride (PVC) produced by polymerization of the monomer vinyl chloride (VCM) is the third-most widely produced plastic and finds applications in flooring, piping, profiles, cables, etc.

VCM production based on ethylene is a mature process, for which high plant reliability and continuous improvement of energy and raw material efficiency are required in order to remain competitive and meet environmental requirements. INOVYN operates PVC production facilities for PVC with world class energy and raw material efficiency, including the plant at Rafnes, Norway.

VCM is produced from ethylene and chlorine in a process involving several chemical conversion steps. C₂H₄ and Cl are reacted to form 1,2 dichloroethane (EDC) in a liquid phase reactor containing homogeneously dispersed promoters to control selectivity. EDC is then thermally cracked to produce VCM and HCl. Oxychlorination of ethylene, where EDC is formed from C₂H₄, HCl and oxygen in a catalytic gas phase reactor, is used to recycle the HCl formed in EDC cracking. In addition, the selective chlorination and hydrogenation are used actively to control the composition of process streams with the aim of improving process efficiency and reduce fouling of process equipment.

Understanding of the chemistry, particularly in the catalytic systems, and reliable process simulation tools are critical elements in this, as well as input to the search for possible step changes in the way of producing VCM. The latter may include recycling of PVC and utilization of raw materials from bio-resources. Nevertheless, the improvements are generally made in steps but mean millions of € saved annually within VCM and Chlorine technology. This still represents significant innovation as the challenges are considerable.