Hi jh5speed,
Our local National Trust house has a very old gas turbine installed in the kitchen.
It consists of an open coal fire (at ambient atmospheric pressure) and a very long vertical jet pipe called a chimney. A turbine (set of fan blades) is placed above the fire and its rotation is converted through a suitable system of bell cranks and levers to turn the spit and roast the meat.
It doesn't seem to be very efficient - would a compressor help?