The detailed oligomerization and autoxidation mechanism for the liquid-phase submodel is generated using Reaction Mechanism Generator (RMG). We seed the mechanism generation using the oligomerization mechanism in the base case debutanizer fouling model (without oxygen) for consistency. For the mechanism generation, we use 40 simulators, each corresponding to the tray liquid at each tray, condenser, and reboiler. We initialize these simulators using the temperatures, major species concentrations, volumetric flow rates, and dissolved oxygen concentrations at each tray, condenser, and reboiler in the debutanizer obtained from the Aspen simulation.