So is the general idea to process the coal dust in some sort of separate gas producer module and feed the resulting gas into a turbine rather like the Lippisch barbecue and stovepipe method, rather than squirting black dust through injectors directly into the combustion chamber?
I have a bizarre picture in my head of a "covert" SR71 leaving a vast black smoke trail behind it as it showers klinker over the USSR to the accompanyment of a mournful "Whooo Whooo" whistle.
How would the poor hobos have ever got aboard at M3.2?