A composition of fuel gas that when mixed with spent catalyst and oxygen has an induction time that allows bubbles to break up while combusting in the regenerator. Bubble breakage in a dense bed avoids generation of a flame that can generate hot spots in the regenerator which can damage equipment and catalyst. The fuel gas can be obtained from paraffin dehydrogenation products, so it can sustain operation of the unit even in remote locations. Heavier streams can be mixed with lighter streams to obtain a fuel gas composition with a desirable induction time to avoid such hot spots. Mixing of a depropanizer bottom stream and/or deethanizer overhead stream with lighter gas streams such as cold box light gas or PSA tail gas can provide the desired fuel gas composition.