Patent ID: 6096195
Filing Date: 2000-08-01
Classification: C10G

Abstract:
A process for hydrotreating a hydrocarbon feedstock that contains sulfur and nitrogen, in which the feedstock is hydrotreated in the presence of a catalyst in a hydrotreatment zone (HDT); a hydrotreated hydrocarbon product, a high-pressure purging gas (12) that contains hydrogen, hydrogen sulfide, and light hydrocarbons (C.sub.5 -), and a first liquid aqueous effluent that contains water and ammonium sulfide are recovered; the first effluent is purified in a stripping zone (SE) to recover a gaseous effluent comprising hydrogen sulfide, H.sub.2 O and ammonia; the gaseous effluent is introduced into a cracking zone that comprises a catalyst, heated between 1000 and 1400.degree. C.; a cracking effluent (9, 11), which contains hydrogen sulfide, H.sub.2 O, hydrogen and nitrogen that results from the cracking of the ammonia are recovered; whereby the process is characterized in that said cracking effluent is cooled to recover a gaseous phase (11) that contains nitrogen, hydrogen, and hydrogen sulfide; said gaseous phase is introduced into a unit (20) for extracting hydrogen sulfide; the gaseous phase from which hydrogen sulfide has thus been removed is passed through a hydrogen recovery unit (SK, and at least part of the hydrogen that is recovered is recycled to hydrotreatment zone (HDT).