Method for the fixed-bed treatment of a heavy fossil-based feedstock comprising a fraction of plastic pyrolysis oil

A process the treatment of a feedstock comprising a heavy fraction of hydrocarbons of fossil origin having an initial boiling point of at least 340° C. and a final boiling point of at least 550° C. and containing sulfur and nitrogen, and a fraction of plastic and/or tire and/or solid recovered fuel pyrolysis oil, said fraction of pyrolysis oil constituting less than 50% by weight of said feedstock, said process comprising:

• a) a hydrodemetallization stage carried out in a fixed bed reaction section comprising at least two permutable reactors, said section being fed at least by said feedstock and a gas stream comprising hydrogen, in the presence of at least one hydrodemetallization catalyst, at a temperature between 300 and 500° C., an absolute pressure of between 5 MPa and 35 MPa and an hourly space velocity between 0.1 and 5.0 h−1,
• b) a hydrotreating stage carried out in a reaction section comprising at least one fixed bed reactor, said section being fed at least by said effluent resulting from stage a) and optionally a gas stream comprising hydrogen, in the presence of at least one hydrotreating catalyst, at a temperature between 300 and 500° C., an absolute pressure of between 5 MPa and 35 MPa and an hourly space velocity between 0.1 and 5.0 h−1,
• c) a stage of separation of the effluent resulting from stage b) carried out in a separation section resulting in a gas fraction and at least one liquid product.