Coal-Burning Turbofan?

From coal to jet-A? Williams is testing just such a fuel on its ubiquitous FJ44 series engine.

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A coal-powered CitationJet? It just might happen. Williams International, the turbofan engine manufacturer, has completed an extended engine run of one of its FJ44-3 turbofans running fuel made from coal. The tests, which included 21 hours of operation and 118 operating cycles, were extremely promising and confirmed, Williams said, the promise of the FJ44, a popular small turbofan engine, to take advantage of alternative fuels in the future. The tests required no modifications to the engine or the test stand.

The fuel in this test was a coal-based formulation that could be produced domestically, say its developers, a team of researchers from Penn State University. And the process, which is currently being developed for coal, might also be applied to waste biomass, municipal solid waste and purpose-grown biomass, like algae.

Unlike jet-A, the new coal-based fuel -- Williams ran 2,000 gallons of it through the test engine -- burns cleaner and with negligible levels of nitrogen, sulfur and aromatics. It also has higher energy density, making it more efficient for longer range on the same amount of fuel per weight.