On my travels I was told that there's a coal burning gas turbine at either Leicester or Leeds Univ can't remember which.
You can run a turbine on any thing that will burn, the main problem with coal dust is that the ash erodes the blades down stream of the combustion chamber.
If memory serves most gas turbine research in the thirties was based on trying to get modified steam turbines to burn coal, which is why Sir Frank Whittle was dismissed out of hand by the then experts when he suggested their use as aircraft power plants.
The other problem with powdered coal is if it gets damp you end up with the worlds largest brickette.
