Yes, the same thing has occurred to me. It's essentially a steam reaction engine, like that built by Hero of Alexandria. Except of course that it doesn't vaporize water by means of an external heat source, it actually makes the water with a strongly exothermic reaction, the heat of which serves to compress the steam that is the reaction product.
When I watch people mowing their lawn or using small gas engines for leaf blowers or string trimmers, I amuse myself by thinking that the fuel tank is actually a very efficient container for a compressed gas.
I try to picture the size a compressed air reservoir would have to be in order to run a leaf blower for an hour or so without a compressor to kick on and replenish it. This seems reasonable because a string trimmer engine has about the same power capacity as the compressed air motor in a hand-held grinder or impact wrench.
When I think of it that way, I realize that the tiny fuel tank in a string trimmer holds thousands of cubic feet of high pressure gas, but is itself tiny and is made of light, inexpensive plastic.
It makes me appreciate the value of the internal combustion engine.
It makes me appreciate the value of the internal combustion engine.The sheeple will only learn that lesson after the Lefties take them all way.