Thanks all, the solvent is water miscible, n-butanol. As both water and butanol rise in the reflux column, it was envisaged that the water would be adsorbed by the eg 3A molecular sieve ( granules ) leaving the n-butanol to trickle back into the reaction flask. Other desiccants like MgSO4 can adversely affect the outcome due to probable ion participation.
Molecular sieves have a water adsorption capacity of approx 20% w/w, retain water upto 200 deg c fluid temps, unreactive neutral conditions, 3A does not adsorb large molecules like n-butanol, can be recycled.