Desalination is simple but VERY expensive. There are two main technologies for desalination:
1. Distillation. Like you said, evaporate and cool down. This is very expensive because water has a very high heat capacity. All that energy has to come from somewhere. On top of this you have to do something with the left over salt. If it is left in the boiler, it will build up further reducing the efficiency, increasing costs.
2. Reverse Osmosis. This involves pushing water using high pressure through a membrane that is fine enough that the salt cannot move past. This is more efficient, but slow and has to have huge scale to supply a city.
Practical engineering on Youtube has a great video explaining the processes and difficulties in desalination. [https://www.youtube.com/watch?v=mxqOPdEUNTs](https://www.youtube.com/watch?v=mxqopdeunts)
Latest Answers