Abstract: Process for the manufacture of 1,2-dichlorethane and of at least one ethylene derivative compound which is different from 1,2-dichloroethane starting with a hydrocarbon source according to which: a) the hydrocarbon source is subjected to a simplified cracking which produces a mixture of products containing ethylene and other constituents; b) the mixture of products is separated at least into a fraction A enriched with compounds which are lighter than ethylene, containing part of the ethylene, into a fraction B enriched with ethylene and into a heavy fraction C; and c) one fraction among fraction A and fraction B is conveyed to the manufacture of 1,2-dichloroethane and optionally of any compound derived therefrom, optionally after having been subjected to an acetylene hydrogenation, while the other fraction is conveyed to the manufacture of at least one ethylene derivative compound manufactured directly starting with ethylene which is different from 1,2-dichloroethane and optionally of any compound derived the

Abstract: Process for the manufacture of at least one ethylene derivative compound starting from a low value residual gas, preferably a ROG, according to which: a) the low value residual gas is subjected to a series of treatment steps in a low value residual gas recovery unit in order to remove the undesirable components present therein and to obtain a mixture of products containing ethylene and other constituents; b) the said mixture of products is separated into a fraction enriched with compounds which are lighter than ethylene, containing part of the ethylene (fraction A), into a fraction enriched with ethylene (fraction B) and into a heavy fraction (fraction C); c) fraction A and fraction B are separately conveyed to the manufacture of at least one ethylene derivative compound.