Method for converting residues incorporating deep hydroconversion steps and a deasphalting step

A process for the conversion of hydrocarbon feedstocks, at least 50% by weight of which boils at a temperature of at least 300° C., comprising the following successive stages:

• stage a), a first deep hydroconversion of said hydrocarbon feedstock in the presence of hydrogen, under an absolute pressure of between 2 MPa and 35 MPa, at a temperature of between 300° C. and 550° C., with an amount of hydrogen of between 50 Sm3/m3 and 5000 Sm3/m3, with a catalyst containing at least one nickel or cobalt Group VIII metal and at least one molybdenum or tungsten Group VIb metal,
• stage b) separation of a light fraction from a part or all of effluent resulting from said first deep hydroconversion, and obtaining at least one heavy fraction, at least 80% by weight of which exhibits a boiling point of at least 250° C., by one or more flash drums in series, or by one or more steam stripping and/or hydrogen stripping columns, or by an atmospheric distillation column, alone or followed by a vacuum distillation column, or by a combination thereof,
• stage c), a second deep hydroconversion of a part or all of the heavy fraction resulting from stage b) in the presence of hydrogen, under an absolute pressure of between 2 MPa and 35 MPa, at a temperature of between 300° C. and 550° C., with an amount of hydrogen of between 50 Sm3/m3 and 5000 Sm3/m3, with a catalyst containing at least one nickel or cobalt Group VIII metal and at least one molybdenum or tungsten Group VIb metal, the overall hourly space velocity for stages a) to c) being 0.05-0.09 h−1, the overall velocity being the flow rate of liquid feedstock of the hydroconversion stage a), taken under standard temperature and pressure conditions, with respect to the total volume of the reactors of stages a) and c),
• stage d) separation of a part or all of effluent resulting from said second hydroconversion into at least one light fraction and at least one heavy fraction, at least 80% by weight of which exhibits a boiling point of at least 300° C.,
• stage e) deasphalting said heavy fraction resulting from stage d), at a temperature of between 60° C. and 250° C., with at least one hydrocarbon solvent having from 3 to 7 carbon atoms, and a solvent/feedstock ratio (volume/volume) of between 4/1 and 9/1, obtaining a deasphalted fraction DAO and an asphalt
• stage f) after optionally distilling, and optionally preliminarily hydrotreating, converting all or a part of the optionally distilled, optionally hydrotreated deasphalted fraction DAO, in a conversion stage operating by fluidized-bed catalytic cracking in the presence of a catalyst comprising alumina, silica, silica/alumina, and optionally comprising at least one zeolite.