From time to time I find myself dissolving potassium nitrate in water (endothermic solvation) and a while back i considered that if i was boil a saturated solution of potassium nitrate that it would be easier than boiling distilled water; as evaporation would have to be exothermic, which would assist boiling. If distilling sea water, i would consider that it would more efficient energy wise to saturate the solution with potassium nitrate and then distill. Compared to just simply distilling the sea water. Distillation is not a practical method of purifying water, considering the existence of reverse osmosis technology. Distillation is still used however as the primary method of obtaining ethanol, from a fermented solution. Energy efficiency is important in in this process, as much of the ethanol produced these days is for renewable energy purposes. Potassium nitrate does not dissolve in ethanol, but other compounds with the same endothermic solvation property might be able to be used. Does anyone know of such compounds and consider that this concept may have merit?