Vinyl Chloride Monomer (VCM)
- Vinyl Chloride or also called Vinyl Chloride Monomer (VCM) is a chlorinated hydrocarbon occurring as a colorless, highly flammable gas with a mild, sweet odor that may emit toxic fumes of carbon dioxide, carbon monoxide, hydrogen chloride and phosgene when heated to decomposition. Vinyl chloride monomer is transported as a liquefied gas.
- VCM holds a great importance as a basic raw material to produce Polyvinyl Chloride (PVC): the world’s third most used synthetic plastic polymer. In 2016, Northeast Asia was the largest consumer of VCM, accounting for over half of the world’s VCM demand, with China as the largest overall player in the VCM market.
- Early on VCM was produce from acetylene by catalytic hydrochlorination, but now nearly all production outside of China is now based on ethylene because it requires less energy cost.
- VCM (from ethylene) is produced by set a of integrated reactions. Chloride + Ethylene + Air à ethylene dichloride (EDC) or 1,2-dichloroethane.
- Series of reaction to obtain EDC can be done either by:
- Direct chlorination: Directly reacting ethylene and pure chlorine, with iron (III) chloride as catalyst. Results in high yields of EDC with high purity.
- Oxychlorination: Reacting ethylene with chloride in hydrogen chloride (this HCL from recycle), with copper (III) chloride as catalyst.
- After the reaction EDC enters the thermal cracking process, carried out at a temperature of 450-550oC and 1-40 bar pressures with pumice or charcoal used as a catalyst. The final step is cooling and separating the exit gases and then purifying the VCM as final product.
Vinyl chloride is a chemical intermediate, not a final product. Due to the hazardous nature of vinyl chloride to human health, there are no end products that use vinyl chloride in its monomer form.
VCM is mainly used to produce Polyvinyl Chloride (PVC) and also used as a raw material for vinyl chloride and vinyl acetate copolymers, vinylidene chloride and vinyl chloride copolymers, etc.
Further processing of VCM is done in several types of industries for:
- Plastic Manufacturing
- Wire and cable manufacturing
- Building/construction materials