Patent ID: 8119745

Claim:
A process for the manufacture of 1,2-dichloroethane starting from a stream of ethane, 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, subjecting said dry gas mixture comprising the stream of products derived from the chlorination reactor R 2 separated in step e) to an absorption A which consists of separating said gas mixture into a fraction enriched with the compounds that are lighter than ethylene containing some of the ethylene (fraction A) and into a fraction F 1 ; d) conveying said fraction A to a chlorination reactor R 1 in which most of the ethylene present in said fraction A is converted into 1,2-dichloroethane, wherein the 1,2-dichloroethane so obtained is separated from the stream of products derived from the chlorination reactor R 1 ; e) subjecting said fraction F 1 to a desorption D 1 which consists of separating said fraction F 1 into an ethylene fraction depleted of the compounds that are lighter than ethylene (fraction C) which is conveyed to a chlorination reactor R 2 , the stream of products derived from this reactor being added to the dry gas mixture subjected to step c) after having optionally extracted the 1,2-dichloroethane formed, and into a fraction F 2 ; f) subjecting said fraction F 2 to a desorption D 2 which consists of separating said fraction F 2 into a fraction enriched with ethylene (fraction B) and into a fraction F 3 , optionally containing the 1,2-dichloroethane formed in the chlorination reactor R 2 then extracted, if it has not previously been extracted, which is recycled to the absorption A, optionally after an additional treatment intended to reduce the concentration, in said fraction F 3 , of the compounds that are heavier than ethane; g) conveying said fraction B to an oxychlorination reactor in which most of the ethylene present in said fraction B is converted into 1,2-dichloroethane, wherein the 1,2-dichloroethane so obtained is separated from the stream of products derived from the oxychlorination reactor and is optionally added to the 1,2-dichloroethane formed in the chlorination reactor R 1 and optionally to that formed in the chlorination reactor R 2 ; and h) 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 g), after having been optionally purged of gases and/or after an optional treatment in order to eliminate the chlorinated products contained therein.