Patent ID: 8163167

Claim:
A process for the deep desulfurization of a heavy pyrolysis gasoline feedstock containing a diolefin concentration, an organic sulfur concentration and a high aromatic concentration, wherein said process comprises: heating said heavy pyrolysis gasoline feedstock to a temperature sufficient to provide a heated pyrolysis gasoline feedstock having a substantial portion that is in a gaseous phase and another substantial portion that is in a liquid phase; introducing said heated pyrolysis gasoline feedstock that is in said liquid phase and said gaseous phase into a reactor vessel, or more than one reactor vessel in series flow arrangement, that contains a hydrogenation catalyst and is operated in a downflow mode; contacting said heated pyrolysis gasoline feedstock in the presence of an added hydrogen treat gas having an H 2 S concentration of at least 100 ppmv with said hydrogenation catalyst at a moderate temperature condition effective to selectively hydrogenate a substantial portion of the diolefins contained in said heated pyrolysis gasoline feedstock to monoolefins and a substantial portion of the organic sulfur in said heated pyrolysis gasoline feedstock to H 2 S, but not at a temperature to significantly hydrogenate the aromatic compounds contained in said heated pyrolysis gasoline feedstock; yielding from said reactor vessel, or more than one reactor vessel in series flow arrangement, a reactor effluent; and separating H 2 S and unreacted hydrogen from said reactor effluent and recovering from said reactor effluent a low-sulfur pyrolysis gasoline product that contains less than 30 ppm organic sulfur compounds.