Dehydration via Pervaporation and Vapor Permeation

We have successfully deposited zeolite and carbon thin films on our commercial ceramic membrane substrate for separation of water through pervaporation and vapor permeation. Due to its aperture size and polar nature, zeolites, such as NaA, have been selected by us to be used as a dehydration membrane which preferentially permeates water over solvents. By operating at higher feed temperatures due to its unique material stability, several process advantages would accrue.

Interstage heaters become unnecessary or minimized.
Evaporative cooling occurs in the modules during pervaporation and hence multiple passes through reheaters are necessary. However, if the feed temperature can be increased to 150 to 200°C, this interstage heating requirement is reduced or eliminated.
Higher temperature higher pressure permeate collection is possible.
By raising the feed temperature (which is less costly and easier to implement), it is possible to operate the condensers at (or near) atmospheric pressure and ambient temperature, eliminating the need for vacuum service and refrigerant based chilling systems. Significant costs savings could be realized.
Higher throughputs are realized.
The productivity of the membranes increase with increasing temperature due to the higher membrane permeance and the higher vapor pressures developed.

In addition, to improve the corrosion resistance, our carbon molecular sieve membrane can perform dehydration involving harsh chemicals, of which existing pervaporation membranes fail due to the lack of material stability. Selected performance data obtained from bench study are listed below:

« Back