One exemplary embodiment can be a process for regenerating catalyst in a fluid catalytic cracking unit. Generally, the process includes providing a feed to a riser of a reaction vessel, and providing a stream to a distributor positioned within a void proximate to an inlet receiving unregenerated catalyst in a regenerator. The feed can include at least one of a gas oil, a vacuum gas oil, an atmospheric gas oil, a coker gas oil, a hydrotreated gas oil, a hydrocracker unconverted oil, and an atmospheric residue.