Process for the hydrotreatment of a gas oil in a series of reactors with recycling of hydrogen

摘要

Process for hydrotreatment of hydrocarbon-containing feedstock comprising sulphur- and nitrogen-containing compounds, comprising:a) separating the feedstock into heavy and light fractions,b) a first hydrotreatment stage wherein the heavy fraction and hydrogen are contacted with a first hydrotreatment catalyst Z1 to produce a first desulphurized effluent,c) separating the first effluent into a first gaseous fraction and a first liquid fraction,d) purifying the first gaseous fraction to produce a hydrogen-rich flow,e) mixing the light fraction with the first liquid fraction to produce a mixture,f) a second hydrotreatment stage wherein the mixture from stage e) and the hydrogen-rich flow from stage d) are contacted with a second hydrotreatment catalyst Z2 to produce a second desulphurized effluent,g) separating the second effluent into a second gaseous fraction and a second liquid fraction,h) recycling at least part of the second gaseous fraction to b) as a flow of hydrogen.