(617o) Equilibrium Shifting of Esterification with Water-Permselective Zeolite Membrane

Ethyl acetate (EtOAc) is one of the important chemical products and used as solvent for ink, synthetic resin, adhesive agent and so on. EtOAc is usually synthesized by the following esterification between ethanol (EtOH) and acetic acid (AcOH) in liquid phase.

AcOH + EtOH = EtOAc + H₂O

It is well known that the esterification is equilibrium-limited reaction. So far, shifting the equilibrium point has been attempted by incorporating membrane separation of water. There are two schemes for water removal: one is the vapor permeation (VP) method to remove the water vapor in the vapor phase at equilibrium with the liquid reacting mixture; the other is the pervaporation (PV) method to remove the water directly from the liquid reacting mixture. This work focused on the vapor phase esterification in flow-type membrane reactor, where water vapor is selectively separated with vapor permeation (VP) using a CHA type zeolite membrane. Advantages in this vapor system, carried out at higher temperature, should be: (1) reaction rate will become larger than that in liquid phase operated at lower temperature, and (2) a higher rate of water vapor permeation (permeability) can be obtained. As an overall, a higher productivity of EtOAc with increasing reaction and permeation rates can be expected.