Other fuels will work. Anything that can be mixed with air and will provide enough BTUs when burned can be used as a fuel. Gas turbine engines have been run on everything from Hydrogen gas to coal dust. Most commercially built engines are designed to run on kerosene, AKA jet fuel. Diesel fuel and alcohol are also popular fuels.
Many experimenters start out with propane.
Once they have a working engine and a little experience, some people convert to liquid fuels like kerosene or diesel. This is probably the most asked question, but I don't know why. The ignition system is by far the easiest part of the engine to build, at least for a non-machinist like me. Above is a schematic of the high voltage power supply I built to power the spark plug on my engine. It produces a continuous spark.