Systems and methods for enhancing the processing of hydrocarbons in a FCC unit by introduction of the coked FCC catalyst from the FCC reactor and a renewable feedstock to the FCC regenerator to facilitate regeneration of the coked FCC catalyst. The renewable feedstock can contain biomass-derived pyrolysis oil. The biomass-derived pyrolysis oil and coke from the coked FCC catalyst are oxidized by oxygen to provide a regenerated catalyst that is recycled to the FCC reactor.