Patent ID: 8071827

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 to an absorption A 1 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 in which most of the ethylene present in said fraction A is converted to 1,2-dichloroethane, wherein optionally, the 1,2-dichloroethane so obtained is separated from the stream of products derived from the chlorination reactor; e) optionally, subjecting the stream of products derived from the chlorination reactor, from which the 1,2-dichloroethane has optionally been extracted, to an absorption A 2 which consists of separating said stream into a fraction F 2 enriched with ethane which is then conveyed back to said fraction F 1 , and into a fraction F 2 â€² enriched with compounds that are lighter than ethane; f) subjecting said fraction F 1 , optionally containing said fraction F 2 recovered in step e) of absorption A 2 , to a desorption D which consists of separating said fraction F 1 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 then extracted if it has not been extracted previously, which is recycled to at least one of the absorption steps, optionally after an additional treatment intended to reduce the concentration of compounds that are heavier than ethane in said fraction F 3 ; 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; 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.