Saltwater Desalinization
This will not work. Centrifugation will only separate heterogeneous mixtures by density. For example, when centrifuging blood, the cells and platelets will separate to the bottom of the tube because they are not in solution. Depending on the lipid concentration in the plasma, a lipid layer may phase separate (not in solution) and move to the top.

The salt in sea water is dissolved in solution. It will not separate. Even if the centrifugation would produce a concentration gradient across the solution, diffusion would counteract that gradient.