Williams International has tested a coal-based, “hydrotreated” fuel in its FJ44-3 engine. The engine burned 2,000 gallons of the alternative fuel in test-stand runs involving 21 hours and 18 cycles. The synthetic fuel’s performance was identical to using Jet-A fuel and required no special engine or test cell modifications. Williams says this testing validates the FJ44 design as being able to take advantage of fuels composed of different compounds and created from different processes.
The fuel was developed by a team at The Pennsylvania State University, with help from Intertek-PARC and Duquesne University. In its final form, the coal-based, upgraded and hydrotreated fuel is a “green” product that is free of nitrogen, aromatics, and sulfur. The fuel also has a higher energy density than typical jet fuels, so it can extend range. Because the raw feed is produced by coal liquification, it can be produced, fully home-grown, from coal in the United States. A similar process could possibly use renewable feedstocks such as waste biomass and municipal solid waste, as well as biomass like algae that does not compete with food sources, Williams said.
Williams International is promoting the development and certification of alternative fuels for commercial aviation. Specific plans include emissions testing and smoke measurement. The company is also a participant in the Commercial Aviation Alternative Fuels Initiative (CAAFI)—an organization that seeks energy security and environmental sustainability through alternative jet fuels.