The Cyclone engine is a high efficiency, compact, and powerful external combustion engine that can run on traditional fuels or biofuels. Created by Cyclone Power Technologies, it is also called a "Schoell Cycle" engine after inventor Henry Schoell. Incorporating a process of heat regeneration, it is touted as a 21st century update to the traditional Rankine cycle steam engine.
This engine has received several awards. It won the Society of Automotive Engineers' AEI Tech Award in 2006 and again in 2008. In 2008, it also won Popular Science Magazine’s Invention of the Year Award.
The engine is comprised of a condenser, a steam generator, and a main engine with valves, cylinders, pistons, and other components. It uses water as both a working fluid and a lubricant, in a closed-loop piston-based system. In an external combustion chamber, water is heated and expands into steam, which creates mechanical energy and powers the engine by moving the pistons. Cooling air then moves through a condenser, is heated in an exhaust heat exchanger, and exits into the furnace in a regeneration cycle that increases the engine's efficiency and compactness.
A one-piece unit with fewer parts and no complicated systems, the Cyclone engine is smaller, lighter, and less expensive to manufacture and maintain than other kinds of engines. An innovative design allows it to operate without the use of motor oil or an oil pump. It also requires no transmission or transmission fluid and runs without the need for an exhaust system muffler, a catalytic converter, or a separate cooling system.
There are multiple environmental benefits of the Cyclone engine. It can run on nearly any kind of liquid or gaseous fuel, from traditional gasoline to palm oil, cottonseed oil, and even chicken fat. Biofuel can be used without the need for fossil fuels to be mixed in, making it a truly carbon-neutral alternative. The Cyclone engine allows for a longer burn time, which burns up more carbon particles and pollutants and results in fewer emissions. It also burns at a temperature lower than the point at which nitrogen dioxide gases is created.
The ways in which the Cyclone engine may be used seem to be unlimited. As development continues, it is speculated it will suitable for use in everything from small generators and garden equipment to cars, trucks, trains, large ships, and more. It may even be able to replace internal combustion engines for applications like transportation and power generation.