PROCESS FOR TREATING A STREAM OF CRACKED GAS COMING FROM A HYDROCARBON PYROLYSIS PLANT, AND ASSOCIATED PLANT

摘要

Process for treating a stream of cracked gas coming from a hydrocarbon pyrolysis plant, and associated plant. This process comprises the separation of an upstream partially condensed cracked gas stream in an intermediate separator (44B) so as to recover an intermediate liquid (136) and an intermediate cracked gas stream (138) and the injection of the intermediate liquid (140) into an intermediate demethanization column (68). The process includes sampling a portion of the intermediate liquid (136) and expanding at least a first fraction (194) obtained from the sampled portion (190). The process comprises bringing the expanded first fraction into heat exchange relationship with the overhead intermediate stream (146) from the column (68) in order for the overhead intermediate stream (146) to be at least partially condensed. The process includes the separation of the partially condensed overhead intermediate stream in a reflux first separator (76) so as to form a liquid stream (148) fed into the intermediate column (68) and a gaseous fuel stream (150).