I was thinking. Now people plan to build factories to transform wood to liquid fuels. But why not run a motor on solid fuel. A diesel spread diesel to a fine particle dust so it burn faster and better. But you can get a explosion by sawdust. Is it not possible to get sawdust in to the motor? Does the exhaust from sawdust damage the motor? Is it possible to build a engine that don’t need a fast burning fuel? Lets say I take a gas tube and put in a sawdust burner with glow wire. I increase the pressure like in a engine and burn the sawdust. This increase the pressure and temperature. I isolate the tube. I now lead the pressure to a air engine. But I don’t want to let out hot air so I have a chamber between were I spray in water that turns to steam and increase pressure and lower the temperature to 120-150 degrees. Now I build 6-8 similar tubes that in turn give pressure to the air engine with an automatic system that remove the ashes and load a tube with sawdust. The air motor is connected to a generator and a compressor to give pressure to the loading of the tube. Can I with this system get a working cheap effective engine system that need only solid fuel like saw dust and similar? Can it at least work as power source to powerplants because wood has only half of the energy as petrol so fuel tank would get bigger? What do you think?