Hydroconversion of a hydrocarbon-based heavy feedstock in a hybrid ebullated-entrained bed, comprising premixing said feedstock with an organic additive

A process for the hydroconversion of a heavy oil feedstock (101) containing a fraction of at least 50% by weight having a boiling point of at least 300° C., and containing metals and asphaltenes, comprising the following steps:

• (a) preparing a first conditioned heavy oil feedstock (103) by blending said heavy oil feedstock (101) with an organic chemical compound (102) comprising at least one carboxylic acid function and/or at least one ester function and/or an acid anhydride function;
• (b) preparing a second conditioned heavy oil feedstock (105) by mixing a catalyst precursor composition (104) comprising an oil soluble organo-metallic compound or complex selected from the group consisting of molybdenum 2-ethylhexanoate, molybdenum naphthanate, vanadium naphthanate, vanadium octoate, molybdenum hexacarbonyl, vanadium hexacarbonyl, and iron pentacarbonyl with the first conditioned heavy oil feedstock (103) from step (a) in a manner such that a colloidal or molecular catalyst is formed when it reacts with sulfur;
• (c) heating the second conditioned heavy oil feedstock from step (b) in at least one preheating device;
• d) introducing said heated second conditioned heavy oil feedstock (106) from step (c) into at least one hybrid ebullated-entrained bed reactor comprising a hydroconversion porous supported catalyst and operating said hybrid ebullated-entrained bed reactor in the presence of hydrogen and at hydroconversion conditions to produce an upgraded material (107), and wherein the colloidal or molecular catalyst is formed in situ within the second conditioned heavy oil feedstock at step (c) and/or at step (d).