Recent Advances in Catalysts and Reaction Kinetics for Heavy Oil Hydroconversion: A Review

Hydroconversion of heavy oils and residues is a key technology for the efficient and clean utilization of inferior feedstocks in the modern refining industry. Its intrinsic complexity arises from the high molecular weight of the feed, the abundance of heteroatoms, polycyclic aromatic structures, and the aggregation behavior of resins and asphaltenes. This review examines advances in heavy-oil composition, hydroconversion reactions, catalysts, deactivation, and kinetics through a multiscale framework linking molecular-structure reconstruction, phase-stability regulation, catalytic functionality, and reaction kinetics. First, the effects of asphaltene aggregation, resin–asphaltene interactions, and oil-phase stability on reactant transport, cracking selectivity, and deposition are discussed, emphasizing how resin–asphaltene interactions may stabilize the oil phase and suppress coke formation. Second, structural regulation strategies for supported sulfide catalysts, bifunctional hydrocracking catalysts, ebullated-bed catalysts, and slurry-phase dispersed catalysts are comprehensively discussed. Optimizing pore architecture, acidic functionality, active-phase dispersion, and deactivation resistance may improve liquid yield, reduce hydrogen consumption, and extend catalyst lifetime. Furthermore, interactions among coke and metal deposition, pore blockage, heteroatom poisoning, and active-phase sintering are analyzed, highlighting the potential of dynamic, multiscale characterization to inform long-cycle industrial operation. Finally, the development of apparent-kinetic, boiling-range lumped, continuous-distribution, molecular-level, and reactor-coupled kinetic models is systematically reviewed. Particular emphasis is placed on the engineering applicability of boiling-range lumped frameworks for process prediction, owing to their direct correspondence with refinery product cuts. Model extrapolability, parameter identifiability, and the coupling of deactivation kinetics are further identified as key challenges that require substantial advances in future research. Integrating feed molecular characterization, catalyst structure design, deactivation-mechanism elucidation, and coupled kinetic modeling may support higher liquid yields, lower coke formation and hydrogen consumption, and more stable long-term operation, providing a basis for efficient and cleaner utilization of inferior oils.