Sustainable, green aviation and the pursuit of fuel alternatives
Fuels derived from biomass are not the only option being pursued to solve the problem of switching away from petroleum-based fossil fuels, or at least getting more mileage from those fuels. U.S. Patent Application No. 20140339367, titled Efficient Low Carbon Emission Airplane Integrating Jet Fuel and Cryogenic Fuel Systems, would protect a hybrid fuel airplane having at least one cryogenic fuel tank conforming to the airplane body’s outer mold line as well as a jet fuel tank located in the airplane’s wing. This configuration, developed by the Boeing Company (NYSE:BA) of Chicago, IL, would introduce the use of cryogenic fuels, which are fuels that require storage at extremely low temperatures in order to remain in a liquid state. Cryogenic fuels could be attractive for the airline industry because they create low emission levels and possess a high energy density per mass unit of fuel. One challenge, however, is that cryogenic fuels require large volume tanks because they have a low volumetric energy density per liter. It is because of these benefits and challenges that Boeing is pursuing alternative airplane designs to accommodate for the use of cryogenic fuels.