Using a fractional distillation column you can also separate filtered sea water into water vapor and brine, at equal pressure, with the brine appropriately hotter so the vapor pressure of water over the brine is the same as over the salt-free water droplets that form on the cold end.
You'd then have to compress the water vapor until it condenses barely hotter than the brine, and use both distilled water and residual brine at their approximately equal temperature (water at higher pressure than brine, though) in ofc separate counter-flow heat exchangers to pre-heat the filtered source (sea) water to the column's operating temperature (i.e., where the source water just starts boiling at the column's operating pressure (you want a decent vapor pressure to have a reasonable vapor density and thus feasible power density for capex reasons)).
Thermodynamically this should match a reverse-osmosis process with equal input/output parameters (I left out that you need pumps/turbines to "losslessly" adapt liquid between ambient pressure and internal operating pressure).
One benefit would be that you could directly heat the brine with solar thermal collectors, to get away without having to compress the vapor to condense it, essentially an open-cycle Type-1 absorption heat pump, with solar feed. (Lacking an evaporator, with the condensed output being the desired pure water, and the absorber being fed with source sea water while the return from the generator after the heat exchanger is just warm brine for discharging. If water and brine need to be sub-ambient, you'd evaporate part of the condensed water to chill both the condensate and the brine output streams. That'd be partially-open-cycle.)
You'd then have to compress the water vapor until it condenses barely hotter than the brine, and use both distilled water and residual brine at their approximately equal temperature (water at higher pressure than brine, though) in ofc separate counter-flow heat exchangers to pre-heat the filtered source (sea) water to the column's operating temperature (i.e., where the source water just starts boiling at the column's operating pressure (you want a decent vapor pressure to have a reasonable vapor density and thus feasible power density for capex reasons)).
Thermodynamically this should match a reverse-osmosis process with equal input/output parameters (I left out that you need pumps/turbines to "losslessly" adapt liquid between ambient pressure and internal operating pressure).
One benefit would be that you could directly heat the brine with solar thermal collectors, to get away without having to compress the vapor to condense it, essentially an open-cycle Type-1 absorption heat pump, with solar feed. (Lacking an evaporator, with the condensed output being the desired pure water, and the absorber being fed with source sea water while the return from the generator after the heat exchanger is just warm brine for discharging. If water and brine need to be sub-ambient, you'd evaporate part of the condensed water to chill both the condensate and the brine output streams. That'd be partially-open-cycle.)