Dehydration of diethylene glycol using a vacuum membrane distillation process

The use of a porous PTFE membrane (pore size = 0.2 mu m) in the dehydration of diethylene glycol (DEG) by a vacuum membrane distillation (VMD) method was studied. Experiments on VMD for the treatment of 85 wt. % aqueous DEG were carried out at temperatures from 70 to 90 degrees C, with stirring from 600 to 1700 rpm and vacuum degrees from 650 to 715 torr. The water contents in the feed and the permeate solution were detected by Karl Fisher titration. VMD for 100 min reduced the water content in the feed solution from 15 wt. % to 2 wt. % at 90 degrees C, 1500 rpm and 715 torr. The separation factor increased from 2500 to 9500 and the total flux declined from 18.5 to 1 kg/m(2) h. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.