Process for the manufacture of 1,2-dichloroethane

A process for manufacturing vinyl chloride, comprising:

• a) subjecting the stream of ethane to a catalytic oxydehydrogenation thus producing a gas mixture containing ethylene, unconverted ethane, water and secondary constituents;
• b) drying said gas mixture thus producing a dry gas mixture, wherein said gas mixture is optionally washed before or after said drying;
• c) after an optional additional purification step, conveying the dry gas mixture to a chlorination reactor supplied with a flow of chlorine so that at least 10% of the ethylene is converted to 1,2-dichloroethane;
• d) optionally isolating the 1,2-dichloroethane formed in the chlorination reactor from the stream of products derived from the chlorination reactor;
• e) conveying the stream of products derived from the chlorination reactor, from which the 1,2-dichloroethane has optionally been extracted in step d), to an oxychlorination reactor in which the majority of the balance of ethylene is converted to 1,2-dichloroethane, after optionally having subjected the latter to an absorption/desorption step e′), during which the 1,2-dichloroethane formed in the chlorination reactor is optionally extracted if it has not previously been extracted;
• f) isolating the 1,2-dichloroethane formed in the oxychlorination reactor from the stream of products derived from the oxychlorination reactor, wherein said 1,2-dichloroethane formed in the oxychlorination reactor is optionally added to the 1,2-dichloroethane formed in the chlorination reactor;
• g) optionally recycling to step a) the stream of products derived from the oxychlorination reactor, from which the 1,2-dichloroethane has been extracted, optionally containing an additional stream of ethane previously introduced in one of steps b) to f), after having been optionally purged of gases and/or after an optional additional treatment in order to eliminate the chlorinated products contained therein;
• and
• h) subjecting the 1,2-dichloroethane so obtained to a pyrolysis thus producing vinyl chloride.

A process for the manufacture of polyvinyl chloride, comprising:

• a) subjecting the stream of ethane to a catalytic oxydehydrogenation thus producing a gas mixture containing ethylene, unconverted ethane, water and secondary constituents;
• b) drying said gas mixture thus producing a dry gas mixture, wherein said gas mixture is optionally washed before or after said drying;
• c) after an optional additional purification step, conveying the dry gas mixture to a flow of chlorine so that at least 10% of the ethylene is converted to 1,2-dichloroethane;
• d) optionally isolating the 1,2-dichloroethane formed in the chlorination reactor from the stream of products derived from the chlorination reactor;
• e) conveying the stream of products derived from the chlorination reactor, from which the 1,2-dichloroethane has optionally been extracted in step d), to an oxychlorination reactor in which the majority of the balance of ethylene is converted to 1,2-dichloroethane, after optionally having subjected the latter to an absorption/desorption step e′), during which the 1,2-dichloroethane formed in the chlorination reactor is optionally extracted if it has not previously been extracted;
• f) isolating the 1,2-dichloroethane formed in the oxychlorination reactor from the stream of products derived from the oxychlorination reactor and is optionally added to the 1,2-dichloroethane formed in the chlorination reactor;
• g) optionally recycling to step a) the stream of products derived from the oxychlorination reactor, from which the 1,2-dichloroethane has been extracted, optionally containing an additional stream of ethane previously introduced in one of steps b) to f), after having optionally being purged of gases and/or after an optional additional treatment in order to eliminate the chlorinated products contained therein;
• h) subjecting the 1,2-dichloroethane obtained to a pyrolysis thus producing vinyl chloride;
• and
• i) polymerizing the vinyl chloride to produce polyvinyl chloride.