Hi fellow science fans! Say I have this 55-gallon drum full of water kept at an approximate constant temperature of 120° that I want to create power from. The air temperature is about 60° I'm thinking a possible way to do this would be to submerge a closed vessel full of a solvent that will boil at say +/- 100° and using the vapor from this solvent to spin a turbine, like a traditional steam generator. I would then like to use the ambient air temperature to condense the solvent back to a liquid for recycling. I imagine someone has tried something like this at some point in history. Is there a name for this sort of generator? Any idea what sort of solvent would have the characteristics I'm talking about at these temperatures? Also, I should mention, the hot water is free and I'm not trying to create "extra" energy from heating water or anything. Basically, pretend i'm using a hot spring the size of a 55 gallon barrel.