When there is no dissolved oxygen present in the feedstock, the fouling growth rate is extremely slow, with a film thickness of micrometers to millimeters for most trays in 1 year, consistent with our finding in the base case study. However, even a concentration as low as parts per million (ppm) of dissolved oxygen can significantly accelerate film growth to centimeters in 1 year. The impacts of dissolved oxygen in the feedstock center on the colder section of the debutanizer. This suggests that the boiling point of the antioxidant is a key design parameter to maximize the contact of the antioxidant and locations most affected by the molecular oxygen contamination, and that one may improve the effectiveness of antioxidant-type additives by introducing them from the condenser. This study presented a comprehensive extension of the multiphase detailed chemical kinetic modeling approach to incorporate the effects of dissolved oxygen in the context of polymer fouling within a distillation column. The fouling model specifically focused on the debutanizer and considered the presence of dissolved oxygen in the feedstock as the primary oxygen source. By explicitly accounting for 4 phases in each tray -tray overhead vapor, tray bulk liquid, liquid absorbed in the fouling film, and the solid in the fouling film on the tray surface -we constructed a detailed representation of the fouling process on the surface of a tray for 40 trays in a distillation column. The oxygen-perturbed polymerization occurring in the tray liquid was modeled using a detailed chemical mechanism. To manage the large number of distinct chemical species involved in the real fouling system, the molecular weight distribution of the oligomers formed in the bulk liquid was represented using the Anderson-Schulz-Flory (ASF) distribution to recover associated film growth contribution. Additionally, a fragment-based modeling approach was employed to describe the film growth chemistry, where the fragment-based reaction templates were modified to incorporate oxygen-perturbed film growth pathways.