Separation of ethylene glycol/water mixtures using NaA zeolite membranes

摘要

Inorganic membranes and particularly zeolite membranes are usually used for the dehydration of organic solvents by pervaporation (PV). This work reports an experimental study on the PV dehydration of ethylene glycol (EG)/water mixtures using commercial nanoporous NaA zeolite membranes. The concentration range investigated (C-EG > 70 wt %) was selected according to existing industrial requirements. The recirculation flow rate was kept at a value of 1.5 L/min. The fluxes and separation factors were monitored as the dehydration proceeded. In addition, the activation energy of permeation (Ea) was calculated. The effect of temperature was investigated in the range 50-70 degrees C. The results obtained demonstrated the successful performance of the membrane for the dehydration of EG/water mixtures. It was observed that at 70 degrees C and with 70 wt % initial EG concentration, larger fluxes and separation factors could be obtained, i.e., 0.94 kg m(-2) h(-1) and 1177, respectively. The Pervaporation Separation Index (PSI) of the membrane was found to be high compared to that of polymeric membranes.