Hydrophilic SOD and LTA membranes for membrane-supported methanol, dimethylether and dimethylcarbonate synthesis

Hydrophilic LTA and SOD membranes have been tested in the selective water removal from methanol (MeOH), dimethylcarbonate (DMC) and dimethylether (DME) thus simulating their synthesis in membrane reactors with CO2 as feed. To further improve the pervaporation selectivity of LTA membranes for an aqueous MeOH solution, Na+ ions located in the 8-membered oxygen ring of LTA were ion-exchanged with larger K+ ions in a KNO3 solution, leading to an improvement of the pervaporation separation factor of the H2O/MeOH mixture from 2.8 to 7.4 at room temperature. Furthermore, the selective removal of steam from the organic compounds MeOH, DME and DMC on supported SOD membranes was investigated at high temperatures by steam permeation. The separation performances of SOD membranes for equimolar mixtures of steam with H-2, CO2, MeOH, DME or DMC, were evaluated in the temperature range from 125 to 200 degrees C. The mixture separation factors for steam from DME and DMC through the SOD membrane were found to be higher than 200 and 1000, respectively. (C) 2015 Elsevier Inc. All rights reserved.