Brief description of the hydrotreatment of a diesel fuel in the top plug in series with recycling of 1996.

摘要

The invention relates to a method for hydrotreating a hydrocarbon feedstock comprising sulphur and nitrogen compounds, which comprises the following steps: a) separating the hydrocarbon feedstock into a heavy fraction and a light fraction; b) performing a first hydrotreatment step by placing the heavy fraction and a stream of hydrogen in contact with a first hydrotreatment catalyst Z1 such as to produce a first desulphurised effluent comprising hydrogen, H2S and NH3; c) separating the first effluent into a first gaseous fraction comprising hydrogen, H2S and NH3, and a first liquid fraction; d) purifying the first gaseous fraction to produce a hydrogen-enriched stream; e) mixing the light fraction with the first liquid fraction obtained in step c) to produce a mixture; f) performing a second hydrotreatment step by placing the mixture obtained in step e) and the hydrogen-enriched stream produced in step d) in contact with a second hydrotreatment catalyst Z2 in order to produce a second desulphurised effluent comprising hydrogen, NH3 and H2S; g) separating the second effluent into a second gaseous fraction comprising hydrogen, H2S and NH3 and a second liquid fraction; and h) recirculating at least one portion of the second gaseous fraction to step b) as a hydrogen stream.