Williams International has completed testing of a coal-based "hydrotreated" fuel in its FJ44-3 gas turbine engine. The engine burned 7,580 litres (2,000USgal) of the alternative fuel during 21h and 118 cycles at Williams' Walled Lake, Michigan facility.
"The engine performance was identical to using Jet-A fuel and required no special engine or test cell modifications for the demonstration," says Williams. "This latest testing validates the flexibility of the FJ44 design to take advantage of alternative fuels composed of different compounds and created from various processes."
The fuel was developed by a team at 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 sulphur. 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 from coal in the USA. A similar process could possibly use renewable feedstocks such as waste biomass and municipal solid waste, as well as biomass such as algae that does not compete with food sources, Williams says.
Williams 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-an organisation that seeks energy security and environmental sustainability through alternative jet fuels.
"Interest in alternative fuels has increased due to oil price volatility, the desire to reduce greenhouse gas emissions, and the desire for energy independence," says Williams.
Source: Flight International
