Method for the selective hydrogenation of a pyrolysis gasoline feedstock with a three-phase reactor

Method for selective hydrogenation of at least polyunsaturated compounds in a liquid phase feedstock comprising a pyrolysis gasoline, which comprises polyunsaturated compounds, in the presence of a gaseous phase comprising hydrogen, wherein the hydrogenation is performed in a three-phase reactor having a reaction zone volume in the presence of a selective hydrogenation catalyst that is dispersed in the liquid phase, the hydrogenation being performed at a molar ratio of (hydrogen)/(polyunsaturated compounds to be hydrogenated) of between 0.5 and 10, at a temperature of between 0° C. and 200° C., at an hourly volumetric flow rate (V.V.H.)—that is defined as a ratio of volumetric flow rate of the feedstock at 15° C. to total volume of the reaction zone—of between 0.5 h−1 and 100 h−1, and at a pressure of between 1 MPa and 6.5 MPa;

• said method comprising:
• a) continuously introducing said liquid phase feedstock and the gaseous phase comprising hydrogen into a three-phase reactor containing a selective hydrogenation catalyst that is dispersed into the liquid phase,
• b) drawing a gaseous phase comprising hydrogen off at the top of the reactor,
• c) drawing a suspension from the reactor and introducing it into a separation zone in such a way as to separate either a phase containing the pyrolysis gasoline that is at least partially selectively hydrogenated and a catalyst-concentrated phase, or a C8− phase that is at least partially selectively hydrogenated and a catalyst-concentrated phase.