Process for converting heavy petroleum fractions that comprise a fixed-bed hydrotreatment stage, an ebullated-bed conversion stage, and a catalytic cracking stage

Abstract

Process for converting a hydrocarbon fraction that is obtained from atmospheric distillation of a crude, comprising a vacuum distillation stage (a) of said feedstock that makes it possible to obtain a vacuum distillate and a vacuum residue; a stage b) for treating at least a portion of the vacuum distillate in the presence of hydrogen in at least one reactor that contains at least one fixed-bed hydrotreatment catalyst under conditions that make it possible to obtain a liquid effluent with a low sulfur content; a stage c) for treating at least a portion of the vacuum residue in the presence of hydrogen in at least one triphase reactor that contains at least one ebullated-bed hydrotreatment catalyst; a stage d) in which at least a portion of the product that is obtained in stage b) is sent to an atmospheric distillation zone from which a light fraction and a heavier liquid fraction are recovered; a stage e) in which at least a portion of the product that is obtained in stage c) is sent to an atmospheric distillation zone from which a light fraction and a heavier liquid fraction are recovered; and optionally a catalytic cracking stage f) in which at least a portion of the heavier liquid fractions that are obtained in stages d) and e) are at least partially cracked into lighter fuel-type fractions.