Sciencemadness Discussion Board

Membranes and Diaphragms for Electrochemical Processes

Waffles SS - 1-4-2015 at 04:43

I want to try some experience with Electrolysis.

One of my problem is Diaphragm.

I dont know what type of diaphragm is needed?

Usually diaphragm use for avoid passing certain substances.

For example filter paper or asbestos sheet are usable for electrolysis of brine and these will avoid contact between Chlorine and -OH.

What type or what Diaphragm is suitable for Electrolysis of Oxalic acid.

I want to reduce Oxalic acid in cathode according to US0798920A.

If Oxalic pass from Cathode part to Anode part then it will oxidize to Carbon dioxide and i should avoid this.




[Edited on 1-4-2015 by Waffles SS]

j_sum1 - 1-4-2015 at 04:51

I have no actual experience with this, but intend to have a go some time soon. The set-up most commonly referred to here is to use an unglazed terracotta flower pot inside a larger bucket. This is effective at keeping your solutions separate while allowing conduction.
One electrode is in the flower pot and the other in the main vessel (obviously). the polarity may be either way but there is usually a preferred setup depending on what your intended product is. Capturing your product in the smaller vessel means it is more concentrated and is probably the better way to go.

Waffles SS - 1-4-2015 at 06:57

Thanks j_sum1 ,

Somebody has experience on ion exchange membrane(Specially Cation Exchange Membrane)?

It seems it is useful for this purpose but i have little information about it

Molecular Manipulations - 1-4-2015 at 08:17

I've used an ion exchange in a Chloralkali cell. I first tried to flower pot thing, which probably worked, but it wasted a lot of current as well as voltage. Next I built a salt bridge. The basic setup I used was two beakers, one with potassium chloride, the other with dilute potassium hydroxide solution. I connected them with an upside down U tube with a filter paper saturated in potassium nitrate solution, each end of the U tube went in one beaker. The anode was connected to the chloride solution, which evolved chlorine and the cathode was connected to the hydroxide solution, which reduced potassium to the metal, which in turn reacted to evolve hydrogen and produce a more hydroxide solution.

ni3rtap - 8-4-2015 at 21:31

Could you post a brief description of the procedure? google has drawn a blank