Scale-up of high performance mordenite membranes for dehydration of water-acetic acid mixtures

Abstract

Mordenite membranes have been successfully synthesized on 80-cm-long mullite supports by secondary growth method. The morphology and quality of mordenite membrane were greatly affected by fluoride concentration, water content and crystallization mode. Compact and high-flux mordenite membranes were obtained with the addition of NaF in precursor gel, which also exhibited a long-term acid stability for a 90 wt% HAc/H2O mixture at 75 °C. Typically, 80-cm-long mordenite membrane prepared with transverse crystallization displayed a permeation flux of ca. 0.97 kg m−2 h−1 and separation factor of ca. 1200 for separating a 90 wt% HAc/H2O mixture at 75 °C. The pervaporation performance was better than that of membranes prepared with vertical crystallization due to the negligible impact of gravity and temperature gradients. These scaled-up mordenite membranes with high reproducibility showed a promising industrial application for dehydration of water-acetic acid mixtures.