Process for converting heavy crude oil fractions, comprising an ebullating bed conversion step and a hydrocracking step

摘要

A process for converting a hydrocarbon fraction comprises a step a) for treating a hydrocarbon feed in the presence of hydrogen in at least one three-phase reactor, containing at least one hydrotreatment catalyst in an ebullating bed, operating in riser mode of liquid and of gas, the reactor comprising at least one means located close to the bottom of the reactor for extracting catalyst from the reactor and at least one means located close to the top of the reactor for adding fresh catalyst to the reactor, a step b) for treating at least a portion of the effluent from step a) in the presence of hydrogen in at least one reactor containing at least one hydrocracking catalyst in a fixed bed under conditions for producing an effluent with a reduced sulphur content, and a step c) in which at least a portion of the product from step b) is sent to a distillation zone from which a gaseous fraction, a gasoline type engine fuel fraction, a diesel type engine fuel fraction and a liquid fraction which is heavier than the diesel type fraction are recovered. The process can also comprise a step d) for catalytic cracking of the heavy fraction obtained from step c).