Cryogenic Heat Engine as a Zero Emission Vehicle 

Picture this: The more cars are driven, the cleaner the air becomes. Sound crazy? It's possible by using a C-H ("cryogenic heat") engine to power cars. A C-H engine is a radically new energy concept being investigated by Drs. Carlos A. Ordonez, Mitty C. Plummer, and Richard F. Reidy at the University of North Texas with support from the Texas Advanced Technology Program. The most intriguing aspect of the concept is that the fuel used by a C-H engine to power a vehicle can be either liquefied air or liquid nitrogen. Liquefied air is produced by taking air from the atmosphere and cooling and compressing it. Liquid nitrogen is similarly produced using nitrogen gas. Because air consists of 78% nitrogen gas, liquefied air and liquid nitrogen have similar properties. In order to run a C-H engine using liquefied air, liquefied air is heated and expanded in much the same way that water is heated and expanded when used to run a steam engine. However, an important difference is that pollution-emitting combustion is not necessary for the heating process. Instead, heat already existing in the atmosphere is used. As a result, the exhaust consists solely of pure, clean, breathable air. In order to prove that the concept is possible, an automobile has been converted for operation using a C-H engine. In the next phase of the planned research effort, a C-H engine electric power system will be developed and used to power an electric vehicle. The electric vehicle will be designed to travel 130 miles on a single tank of fuel. Assuming that solar energy is used to produce the fuel, the cost of fuel for operating the electric vehicle can potentially reach less than 10 cents per mile. As an environmental benefit, liquefied air and liquid nitrogen production systems remove undesirable airborne pollutants from the air. As a result, the more that cars powered by C-H engines are driven, the cleaner the air becomes.

More information can be found in our papers:

Website maintained by R.F. Reidy and last updated December 17, 2001.