There are currently many different concepts including switching from the normal jet fuel to liquid natural gas, the double bubble concept aircraft, and the hybrid fuel cell / gas turbine systems. Some of the advantages of using liquid natural gas(LNG) is being able to use the same engines that are currently equipped, there would have to be some slight modifications to the combustor to account for the change in combustion temperatures and fuel injection. Liquid natural gas tends to be cleaner containing 80% less sulfur and 80% les particulate matter than oil and diesel. Of course with the advantages come many disadvantages, to liquify the gas it needs to be cooled to negative 260 degrees fahrenheit and will need to be vaporized back into a gas before it reaches the combustion chamber. Another difficulty is the space it takes up even after liquefying the natural gas its volume can be reduced by more than 600% but it still takes up twice the amount of space that an equal amount of jet fuel does. This makes the conversion to liquid natural gas a difficult one because space is already limited on aircraft and needing to double the amount of space to carry the same amount would be difficult to do. Airplanes also have a unique issue when it comes to liquid natural gas, as the plane climbs it goes from 1 atmosphere of pressure at ground …show more content…
This would allow for a Reversible-Regenerative Fuel Cell Power System, which would be comprised of a fuel cell and an electrolyzer. Hydrogen and oxygen would react in the fuel cell to form electricity and water. The electricity would go to power the aircraft electrical systems and the water would be fed to the electrolyzer to be turned back into hydrogen and oxygen for reuse. The use of a Solid Oxide Fuel Cell / Gas Turbine(SOFC/GT) would use several methods to overall produce higher efficiency in energy conservation. This hybrid system would combine a gas turbine engine and a solid oxide fuel cell, both systems would receive pressurized air from the engine intakes. The high temperature exhausts would combine to drive the turbine in the gas powered engine. This system produces both mechanical and electrical energy without the need of a generator that burdens the main