Method and installation using several catalyst beds in series for the production of gas oil has a low sulfur content

A method for hydrotreating gas oil comprising:. A first step of desulfurization of gas oil in a first catalytic zone containing a desulfurization catalyst ,. An at least partial removal of hydrogen sulphide formed after the first step ,. One or more stages of desulfurization in one or more catalytic zones comprising a desulphurization catalyst. Desulphurization in this reactor is more effective due to the partial pressure of H2S much lower, in which the distribution of the catalyst in the different areas is selected to make the most of the catalytic activity, and thus minimize necessary catalyst volume for a given unit of capacity, operating at fixed temperature and operating pressure, so as to obtain a deeply desulfurized diesel fuel.