Using of zeolite NaA membranes for improved glycol dewatering in a pilot plant for natural gas drying

The dehydration of natural gas in production and storage facilities all over the world is dominated by Methylene glycol (TEG) dehydration plants. The regeneration of TEG is done by distillation at a temperature range of 190 to 205°C. To investigate an alternative to the conventional regeneration of Methylene glycol (TEG) from the gas drying process by distillation a first pilot plant was built using hydrophilic zeolite membranes for dewatering TEG. Laboratory studies and investigations at a dehydration plant showed that TEG can be regenerated by molecular sieve membranes. The regeneration temperature and the TEG recirculated quantity can be reduced. The pilot plant is completely integrated into a gas drying plant on an underground gas storage. Before installing 20 m2 of membrane area in the pilot plant extensive investigations were done on lab scale leading to further improvements of the membrane permeation abilities. Water contents in TEG of about 0.5 wt.% were achieved. First results gaining from the pilot plant showed that a high permeance (> 0.30 kg/(m2h),) was reached and could kept constant. The permeance increase strong with the water content of the TEG. The stringent requirements for the separation factor, i.e. the selectivity, has been solved with a TEG-content in the separated water < 2 g/l. The next step is to use a 19-channel tube instead of 4- channel tubes