WME has developed a method for regeneration of air-gas separation membranes, a technique which up until now has not been available in the market.
For years it has been a well-known problem that membranes may often be exposed to contamination, and as a consequence will become deficient in terms of performance.

Air-gas separation membranes are sensitive to contaminations from hydrocarbon aerosols/liquid (i.e. oil products) in the sense that such contamination cannot be removed nor can the membrane be regenerated, without running the risk of destroying the membrane. Most membrane based nitrogen generators have traditionally been equipped with oil lubricated feed air compressors, which increases the risk of oil contamination of the membranes.
Traditionally, this problem has been dealt with by applying traditional filtration techniques upstream the membrane, and increasing the feed air temperature after filtration, in order to create a gap between the actual temperature and dew point temperature of oil & water vapor. Even though filtration equipment is installed, there will always be a risk of oil vapor carryover into the membrane. One of the situations that may contribute to this risk is that the traditional air-gas membrane normally has a recommended max. operating temperature of 50 °C.
The compressor cooling water available may have a temperature of 36 °C, which, owing to the feed air temperature rise across the compressor, may result in a feed air temperature of as much as 46 °C, prior to the temperature increase required to avoid vapor condensation. This leaves us with a temperature gap of only 6 °C, which is not enough to avoid vapor condensation, because there is a temperature drop higher that this across the membrane, during the separation process.

With the new ETech membranes, these problems are avoided, because, at first, the membrane material, polyamide, consists of a single composition, and not, as many other membranes, a dual composition, where the governing membrane is a thin layer applied on to a substructure. The two layers are normally of different materials. The polyamide may withstand a much higher temperature (typically as much as 130 °C), and may easily operate at a temperature of 60 °C, thus avoiding the risk of vapor condensation owing to lower operating temperatures.

If however, there should be a vapor carryover, due to filtration failure or excess oil carryover from compressor, then the ETech membranes may be regenerated. ETech can therefore offer an exchange arrangement, provided that ETech membranes are already installed. It is quite apparent, the cost savings in such an arrangement, as opposed to purchasing brand new membranes.

The Life Cycle Cost of Nitrogen generator can be reduced with as much as 60% compared to a normal membrane set up, and will also contribute to increased safety, in terms of regularity and system capacity.

Benefits:

• 60 percent Life Cycle Cost reduction with regeneration of membranes
• Minimum energy usage with application of ETech patent
• 50 percent less footprint
• Increased safety