Improved performance of vacuum membrane distillation in desalination with zeolite membranes

A supported Mordenite Framework Inverted (MFI) zeolite membrane with a length of 30 cm was synthesized by the secondary growth method using a fast heating profile for the template removal (calcination) step. The presence of defects into the zeolite layer (before and after calcination) was assessed by means of single gas permeation tests. Afterwards, the membrane performance was evaluated in Vacuum Membrane Distillation (VMD) for desalination. Two cleaning procedures were applied between consecutive experiments on salty solutions and their efficiency compared. NaCl rejections of 99.9% were achieved for feeds ranging from 0.2 M to 0.9 M, dropping down to 97% for the 1.2 M feed. The highest trans-membrane flux (20.6 kg m−2 h−1) was measured for 0.2 M feed, by working at 70 °C and 120 L/h.