The solvent dehydration process takes place through beds of zeolites that adsorb the water present in moist solvents.
During adsorption, molecular sieves absorb the moisture until saturation is reached. The exothermic reaction that occurs allows the quality of the dehydrated solvent at the outlet to be monitored.
The most commonly used zeolites in these applications are type 3A, due to the correct micropore size that allows the adsorption of water molecules but not solvent molecules.
Once saturated, the zeolite beds are regenerated using inert gas such as nitrogen, which is heated to about 210°C to desorb the water. The water is then condensed by cooling in condensation batteries and sent to a guard bed before being expelled.
This treatment restores the adsorption capacity of the zeolites to their original state.
