Thread Content
The industrial production of vinyl chloride first began in the 1930s, through an addition reaction using calcium carbide acetylene and hydrogen chloride. As the demand for vinyl chloride increases, efforts are being made to find cheaper raw material sources for its production. In the early 1950s, ethylene became a more economical and suitable raw material for producing vinyl chloride. An industrial production route for manufacturing vinyl chloride from ethylene and chlorine has been developed. This process includes the direct oxidation of ethylene to produce dichloroethane, and the cracking of dichloroethane to produce vinyl chloride. Subsequently, it was observed that during the dichloroethane cracking process, hydrogen chloride is formed in addition to vinyl chloride. Thus, the industry conceived that vinyl chloride could be produced from hydrogen chloride along with the acetylene production process. CH2=CH2 + CL2 → CH2Cl-CH2Cl; CH2Cl-CH2Cl → CH2=CHCL + HCl. In the late 1950s, the ethylene oxychlorination process was developed to meet the growing demand for vinyl chloride. This method is known as the equilibrium process, as it involves the use of ethylene and chlorine to produce vinyl chloride without any net consumption of hydrogen chloride. To this day, a small amount of vinyl chloride is still produced through the calcium carbide-acetylene and acetylene-ethylene methods, but the vast majority of vinyl chloride is manufactured via the equilibrium process based on ethylene and chlorine. Equation: 2CH2=CH2 + CL2 + 1/2 O2 → 2CH2=CHCL + H2O