a reaction riser configured to receive a mixture comprising a hydrocarbon feed and a cracking catalyst and crack the hydrocarbons to produce cracked hydrocarbons comprising light olefins and a spent catalyst comprising residual hydrocarbons adsorbed thereto;

a stripping zone fluidly coupled to the reaction riser and encompassing at least a portion of the reaction riser, wherein the stripping zone comprises:

a stripping medium inlet configured to receive a stripping medium;

a plurality of internals configured to (a) strip the residual hydrocarbons from the spent catalyst via the stripping medium and/or (b) provide heat to the reaction riser;

an outlet fluidly coupled to the stripping zone, configured to release stripped spent catalyst from the stripping zone; and

a catalyst regenerator fluidly coupled to the outlet, wherein the catalyst regenerator is configured to regenerate the spent catalyst to produce flue gas and a regenerated catalyst;

wherein the internals comprises heating plates coupled to 1) an internal wall of the stripping zone and/or 2) heating plates submerged in the stripping zone;

wherein the stripping medium comprises steam, air, dry gas, or combinations thereof;

wherein the stripping internals is configured to provide heat to the reaction riser by heating a heating medium in contact with the reaction riser; and

wherein the heating medium is selected from a hot oil, the stripping medium, the flue gas produced by the catalyst regenerator, a gas turbine, a molten salt, or combinations thereof.