2026 Volume 69 Issue 5 Pages 219-229
Residue fluid catalytic cracking (RFCC) is a crucial technology for converting heavy oils into valuable light fractions. Polycyclic aromatic hydrocarbons (PAHs) in heavy oils have conventionally been regarded as stable and difficult to crack, but we found that decomposition can proceed through hydrogen transfer reactions with coexisting substances, such as naphthenes, paraffins, and aromatic ring side chains. This article introduces our research findings on the catalytic cracking of PAHs in the RFCC process specifically the effects of the number of aromatic rings, types of coexisting substances, and composition and degradation states of the catalyst on PAH conversion. Based on detailed product analyses, the reaction pathways and rate-determining steps were also determined. Furthermore, we discuss the development of an interpretable machine learning model to predict product compositions and extract key reaction factors for catalytic cracking with complex feedstocks. This model provides data-driven evidence that the interaction between hydrogen donors and PAHs contributes to both suppression of coke formation and promotion of decomposition. These findings are expected to enhance heavy oil upgrading efficiencies in petroleum refining.
