Method, including a hydrogenation step, for treating plastic pyrolysis oils

A process for treating a feedstock comprising a plastics pyrolysis oil comprising chlorinated compounds, said process comprising:

• a) a hydrogenation step performed in a hydrogenation reaction section, containing at least one fixed-bed reactor containing n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrogenation catalyst, said hydrogenation reaction section being fed at least with said feedstock containing the plastics pyrolysis oil containing chlorinated compounds and a gas stream comprising hydrogen, said hydrogenation reaction section having an average temperature of between 14° and 400° C., a partial pressure of hydrogen of between 1.0 and 10.0 MPa abs, and an hourly space velocity of between 0.1 and 10.0 h−1, an outlet temperature of the reaction section of step a) being at least 15° C. higher than the an inlet temperature of the reaction section of step a), to obtain a hydrogenated effluent,
• b) a hydrotreatment step performed in a hydrotreatment reaction section, containing at least one fixed-bed reactor containing n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrotreatment catalyst, said hydrotreatment reaction section being fed at least with said hydrogenated effluent obtained from step a) and a gas stream comprising hydrogen, said hydrotreatment reaction section having an average temperature of between 25° and 430° C., a partial pressure of hydrogen of between 1.0 and 10.0 MPa abs, and an hourly space velocity of between 0.1 and 10.0 h−1, an average temperature of the reaction section of step b) being higher than an average temperature of the hydrogenation reaction section of step a), to obtain a hydrotreated effluent,
• b′) a hydrocracking step performed in a hydrocracking reaction section, containing at least one fixed bed containing n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrocracking catalyst, said hydrocracking reaction section being fed at least with said hydrotreated effluent obtained from step b) and a gas stream comprising hydrogen, optionally being additionally fed with the cut comprising compounds having a boiling point greater than 175° C. obtained from step d), said hydrocracking reaction section having an average temperature of between 25° and 450° C., a partial pressure of hydrogen of between 1.5 and 20.0 MPa abs, and an hourly space velocity of between 0.1 and 10.0 h−1, to obtain a hydrocracked effluent,
• c) a separation step, fed with the hydrocracked effluent obtained from step b′) and an aqueous solution, said step being performed at a temperature of between 5° and 370° C., to obtain at least one gaseous effluent, an aqueous effluent and a hydrocarbon-based effluent, wherein step c) comprises an injection of an aqueous solution into the hydrotreated effluent obtained from step b), or the hydrocracked effluent obtained from the optional step b′), upstream of the separation step, and
• d) a step of fractionating all or a portion of the hydrocarbon-based effluent obtained from step c), to obtain at least one gaseous effluent and at least one cut comprising compounds with a boiling point of less than or equal to 175° C. and one hydrocarbon-based cut comprising compounds with a boiling point of greater than 175° C.