Ion exchange using graphite

[gatewood]

Self-explanatory, can the conductive properties of graphite (or near graphitized charcoal/coke) be exploited to make ion exchange membranes?

[chenbeier]

Graphite  has electrical conductivity, but has no positive or negative charges . This you need to exchange ions: cathion plus or anion minus.

Graphite has adsorbtions capabilitis. You can remove a lot of impurities. Used in water Filters.

Edited June 8, 2021 by chenbeier

[gatewood]

I see, pretty new to the actual workings of ion exchange resins. What exactly do you mean with "chargesplus"?

[chenbeier]

Mistyping

[gatewood]

oh, haha.

But say, if I add a small current through it (not so much so as to electrify the water) to negatively charge it, will it become good at trapping cations?

[chenbeier]

Yes, that is a common technical procedure to do electrolysis. Instead of a metal, also a Graphite Elektrode can be used.

If you have salt water NaCl, then on Anode chlorine gas and on cathod side hydrogen will be developed. Sodiumhydroxide will remain.

Edited June 8, 2021 by chenbeier

[SergUpstart]

Graphite can be used as a material for the anode of the electrolyzer. The graphite anode is gradually destroyed during the electrolysis process, but it does not pass into the solution, but precipitates. And the membranes are made of cotton paper, although at present there are membranes made of polymer material that serve for a very long time.

14 minutes ago, chenbeier said:

If you have salt water NaCl, then on Anode chlorine gas and on cathod side hydrogen will be developed. Sodiumhydroxide will remain.

A little more complicated, some of the chlorine will react with NaOH to form oxygen-containing chlorine salts, such as NaClO3

[chenbeier]

Thats correct. But for this reason you need diaphragma compartments that NaOH is not reached the Anode. And also the right current density, so no Oxidation to chlorate takes place.

Tons of NaOH is produced  in this way.

[gatewood]

1 hour ago, chenbeier said:

Yes, that is a common technical procedure to do electrolysis. Instead of a metal, also a Graphite Elektrode can be used.

If you have salt water NaCl, then on Anode chlorine gas and on cathod side hydrogen will be developed. Sodiumhydroxide will remain.

Yes for sure, but what I propose is minimal electronegativity, so it only becomes a sort of magnet for cations, without making an actual electrolysis reaction.

1 hour ago, SergUpstart said:

Graphite can be used as a material for the anode of the electrolyzer. The graphite anode is gradually destroyed during the electrolysis process, but it does not pass into the solution, but precipitates. And the membranes are made of cotton paper, although at present there are membranes made of polymer material that serve for a very long time.

A little more complicated, some of the chlorine will react with NaOH to form oxygen-containing chlorine salts, such as NaClO3

The cotton paper membranes... you mean the ones used to separate electrodes during the chloralkali process?

Edited June 8, 2021 by gatewood

[chenbeier]

Its kind of polarisation, but how will you control it, that no reaction takes place. To keep voltage below redoxpotential, but is it enough. The goal of ion exchange is to get DI water at the end.

[gatewood]

Well, yes you're right there, it would be hard to get there (to deionized water, which is what I want). How about this:

1. Thoroughly filter water with sand, HEPA and activated carbon filters.

2. Boil it a bit to remove dissolved gases.

This way, we reduce contaminants to a bare minimum, only ions remains.

3. Pass them through electronegative and electropositive graphite electrodes (this will trap ions)

If any reaction did take place, and i end up with things like sodium or potassium chlorate, then those can then be filtered with another round of activated charcoal.

[SergUpstart]

20 minutes ago, gatewood said:

The cotton paper membranes... you mean the ones used to separate electrodes during the chloralkali process?

And those used in water ionizers. (The water ionizer is essentially an electrolyzer)

3 minutes ago, gatewood said:

Well, yes you're right there, it would be hard to get there (to deionized water, which is what I want). How about this:

1. Thoroughly filter water with sand, HEPA and activated carbon filters.

2. Boil it a bit to remove dissolved gases.

This way, we reduce contaminants to a bare minimum, only ions remains.

3. Pass them through electronegative and electropositive graphite electrodes (this will trap ions)

If any reaction did take place, and i end up with things like sodium or potassium chlorate, then those can then be filtered with another round of activated charcoal.

Isn't it easier to distill water in a distiller?

[gatewood]

2 hours ago, SergUpstart said:

And those used in water ionizers. (The water ionizer is essentially an electrolyzer)

ok, can I ask you if you could elaborate on that... please? (about the whole cotton membrane)

Edited June 8, 2021 by gatewood

[chenbeier]

5 minutes ago, SergUpstart said:

And those used in water ionizers. (The water ionizer is essentially an electrolyzer)

Isn't it easier to distill water in a distiller?

I  would think so, or use reverse osmosis.

[gatewood]

Well, distilled water is not deionized water (some azeotropes carry on) and it is far more energy intensive. Also my hypothetical electrode technique wouldn't require regeneration (which can get expensive) and no resins.

Edited June 8, 2021 by gatewood

[gatewood]

I get just how unimaginative you people are.

[John Cuthber]

11 hours ago, gatewood said:

I get just how unimaginative you people are.

Do you understand the distinction between " we can not imagine" something and " we recognise the physical impossibility (or impracticability) of something?

Your idea seems to be a less practical version of this.
https://en.wikipedia.org/wiki/Electrodialysis

 

[exchemist]

14 hours ago, gatewood said:

I get just how unimaginative you people are.

Any fool can ask questions. Providing answers that are valid is a little harder, considering that imagination does not help much with that. 

 

[Phi for All]

4 hours ago, exchemist said:

Any fool can ask questions. Providing answers that are valid is a little harder, considering that imagination does not help much with that. 

People who are "pretty new to the actual workings" of science often eschew rigorous study in favor of the less intense intuition and imagination path. Until you understand the actual workings a bit better, it can seem intuitive that science should be intuitive. Rigor is often misunderstood as being hidebound.

[gatewood]

On 6/10/2021 at 4:59 AM, John Cuthber said:

Do you understand the distinction between " we can not imagine" something and " we recognise the physical impossibility (or impracticability) of something?

Your idea seems to be a less practical version of this.
https://en.wikipedia.org/wiki/Electrodialysis

 

Well that's exactly the kind of feedback I'm looking for, most appreciated (that's why I'm here, to learn from the experts).

If you (I mean, not yourself, per se) only have: "well go try distillation or reverse osmosis" to say, when I'm proposing some brainstorm idea, then it seems, I have to recur to stronger criticism, to get the actually good answers (which I have, which I'm thankful for).

Edited June 11, 2021 by gatewood