I am trying to dehydrate alcohol aqueous mixtures by using a mixed matrix membrane.
I mean for alcohol dehydration via a Pervaporation membrane which I used once, is there any problem to reuse it for another condition?would the membrane performance in the second time decrease because of its using before?
Hi,
You can dry your membranes at 60-70 degrees in vacuum oven. By this method you can reuse the membranes. However, it will show slightly lower performance. You can also check the weight of the membrane before and after drying.
Dear Parimal thank you, I guess the flux of the membrane would decrease. as a matter of fact, I am wondering if its selectivity would be affected too?
Certainly! It will affect the selectivity as well. I have performed PV experiments with real bioethanol feed and my membranes showed reduced flux and selectivity.
Perform nitrogen adsorption of your membranes and you will get an idea more realistically.
Dear Zohreh Raeisi, of course it depends on membrane (material, composition, various methods of preparing, etc). Any case there are industrial plants producing absolute alcohol and degidration of organic substances. Sometimes they use membranes of 2000 m2. It would be impossible to change these membranes every time. We should take into account that polymer membranes could (exactly) change their properties during pervaporation process. On the other hand it is a task to make the membrane of high stability and with approximatelly stable perfomance. By the way, in some cases the membrane perfomance could be better after the first use, due to swelling and other reasons. Of course it is not a rule. Any case I am sure that for relatively precision scientific experiments one should use a new membrane (of the same materias and composition) in every new experiments. With best wishes - Alexander.
Dear friend,
As mentioned as above,it depends on material composition,feed solution and preparation condition.But ideally it should be stable during separation experiments ,so we can reuse membrane.Mostly Pervaporation membrane is cross-linked membrane with controlled swelling,which affect the selectivity and flux directly.If your membrane have good cross-linking density which is stable during pervaporation separation than you can reuse it easily.During reusing you have to just take the reading after minimum 1 hour,because membrane established equilibrium with feed and permeate during this time, according to swelling property.
Dear Toilkka, Parimal and Sanhay, I really appreciate your help...best wishes...
Cleaning instructions for organophilic polymeric membranes. http://pervaporation-membranes.com/downloads/datasheets/
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