New design: there is a piston engine, similar to the type that runs off of compressed air. It is powered by proprietary cartridges that contain compressed exhau

New design: there is a piston engine, similar to the type that runs off of compressed air. It is powered by proprietary cartridges that contain compressed exhaust fumes. Cartridges are available in several different scents: 2-stroke, bunker fuel, trash-to-energy, coal, car fire, 100LL, tobacco, crematorium, etc. It meets the requirement.