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Author: Subject: Homemade carbon electrodes
Hexabromobenzene
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[*] posted on 18-2-2024 at 21:35


I conducted several more experiments with electrodes with saturated polyurethane varnishes and alkyd. After pyrolysis, all of them become and sound like ceramic with a weak blow. The impregnation of thermoreactive resin turns them into a semblance of glassy carbon. Theoretically, you can bake a mixture of coal with thermorectative resin without sugar. However, thermoreactive resins are prone to cracking when heated. It is probably better to bake carbon foam from coal powder and sugar, but only then soak it with thermoreactive resin. This resembles a reinforcement of epoxy fiberglass

The more affordable composition of sugar and phosphate ammonium was founded. This glue forms a crosslinked polymer and gives 2 times more carbon than with sugar pyrolysis


[Edited on 19-2-2024 by Hexabromobenzene]
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[*] posted on 8-4-2024 at 13:26


I found a cheaper and effective replacement of binder sugar for the production of carbon electrodes!
Sugar forms only 20% carbon for pyrolysis, which is very small. Also, carbon foam from sugar has small strength
I recently found information on sugar-amino adhesives. The simplest diammonium sugar phosphate 80 20. This glue, unlike sugar, forms a crosslinked polymer and gives up to 60% carbon for pyrolysis. However, a large amount of phosphorus will be a problem when baking the carbon electrode
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6960737/

More recently, I invented my binder for electrodes based on wheat flour:

150 grams of wheat flour, 200 ml of water and 30ml 15% hydrochloric acid is mixed and heats up in a boiling water bath 10 hours .Gluten reacts with sugar in an acidic medium with the formation of soluble amino products.
During pyrolysis, this glue behaves differently than sugar or molasses made of starch. First, the excess of glucose decomposes. Then there is a reaction between sugar and dissolved protein with the formation of a crosslinked polymer, which is charred (the smell differs from the smell of burnt sugar). The result is much more carbon than from the clean sugars and it has greater mechanical strength.

For the manufacture of carbon electrodes, I recommend using this glue. However, with it will not be possible to make a whole piece of carbon without pores. To do this, you need a polymer that is become solid at a ROOM TEMPERATURE to avoid the formation of gas bubbles.


[Edited on 8-4-2024 by Hexabromobenzene]
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[*] posted on 19-4-2024 at 20:07


I experienced another binder for carbon electrodes. This time from oatmeal.
900 grams of oatmeal 1.5 liters of water and 120 ml of 15% hydrochloric acid were mixed and heat about 1 day at 90-100 degrees. The resulting liquid smells like apples and cinnamon
During filtering, it was lost up to half the solution. This is probably due to cellulose . When using wheat flour, filtration is not required

The carbonization of this solution showed that it forms significant amounts of carbon (possibly more than from wheat flour) more strong than from sugar. Unlike the binder from wheat flour during carbonization, there was no smell of burnt sugar.
This means that all glucose reacted with proteins. Wheat flour contains 80% starch and 10% protein. Oatmeal contain 70% starch and 13% protein
Probably in oatmeal, the ratio of carbohydrates and proteins closer to the stichiometric

Definitely sugar-amine binder is better than sugar for the manufacture of carbon electrodes

[Edited on 20-4-2024 by Hexabromobenzene]

[Edited on 20-4-2024 by Hexabromobenzene]
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[*] posted on 21-4-2024 at 15:13


Another binder for carbon electrodes was prepared. Gluten was extracted from 1200 grams of wheat flour using water and added to 700 grams of flour. 1000 ml of water and 100 ml of 15% hydrochloric acid were added to the gluten and flour mixture
The mixture was also heated to 90-100 degrees for 1 day. When carbonation, there was no burnt sugar smell like a binder without gluten addition flour.
The carbon produced from this binder is different from the previous one. It is less foam-like and harder than the previous 2

Conclusion: for a more complete reaction with sugars in flour, 2-3 times more protein is required than what was initially in the flour.
Bran contains a suitable ratio of proteins and sugars. There are also a lot of pentoses, which quickly form addition products with amino acids
However, lignin and cellulose residues create problems during filtration

Many strong odors are observed during the preparation of binders. Sometimes it looks like cinnamon, sometimes like parquet varnish or chipboard glue.
These are probably reaction products of Maillard reaction and similar

[Edited on 21-4-2024 by Hexabromobenzene]
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[*] posted on 1-5-2024 at 09:29


After a few more experiments, I finally understood how the binder from flour works.

After filtering of flour glue, the quality of carbon after carbonization drops sharply. The amount of carbon remains higher than after a carbonization of sugar and it is stronger. However, carbon precipitation obtained from non filtered binding from flour is very homogeneous.

A binder of whole grain flour was made. It was very viscous because of a large amount unhydrolyzed flour

So after the flour hydrolysis in the solution, the gluten suspension remains, which crosslinks sugar at a pyrolysis temperature. Therefore, it is necessary

If, during pyrolysis, the binder is pressed with a sheet of metal, then a dense carbon precipitate is obtained. I expect that electrodes of excellent quality will be made of wheat flour binder. Much better than sugar. The solution after filtering is suitable for use for impregnation of the electrode
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[*] posted on 29-6-2024 at 19:21


I made a new binder. This time I used bones extract or gelatin . 1 to 4 to sugar in weight and a little acid. This composition forms a compact layer of carbon with good shrinkage. I think this is the best option.
You can use any water -soluble organic amino acid

Is the this theme interesting to anyone?
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[*] posted on 29-6-2024 at 21:23


Quote: Originally posted by Hexabromobenzene  
Is the this theme interesting to anyone?
I'm interested enough to follow your progress,
but not enough to try myself.

As you are investigating primarily the fabrication of electrodes,
I think that you need to have a measure of electrode durability in electrolysis duty.
eg amp.hours per square centimeter.

Hardness and conductivity are good,
and probably good indicators of potential performance as an anode,
but how long will each composition survive use as an electrode?




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[*] posted on 30-6-2024 at 00:09


Interesting Artikel how the old Bunsen elements made there Carbon Anode.
https://dingler.bbaw.de/articles/ar156073.html#:~:text=Bunse...
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[*] posted on 30-6-2024 at 01:03


When I will have time, I will check the electrodes. In any case, they will work at least a day

I wrote about sugar many times. This is a bad binder. Electrodes crumble from it. This can be corrected by impregnating the workpiece of epoxy or other resin and then burn it, but it is expensive

Sugar forms 20% carbon during carbonization. Sugar-amino binders up to 50-60 and this carbon is solid and durable. This is more affordable and safer than phenol-formaldehyde resin

[Edited on 30-6-2024 by Hexabromobenzene]
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[*] posted on 30-6-2024 at 01:56


Thats why later down they used Tar as binder because lot of more carbon
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[*] posted on 30-6-2024 at 12:25


Quote: Originally posted by Hexabromobenzene  

Is the this theme interesting to anyone?

I find your work very interesting. It's an easy and affordable method to produce decent pyrolytical carbon from something as mundane as oatmeal or gelatine. It can find other applications than electrodes. For example, nozzle inserts in rocket motors.

Have you measured the density of produced carbon? How hard it to scratch?




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[*] posted on 30-6-2024 at 15:06


The workpiece obtained by baking charcoal with sugar is scratched with a fingernail. When impregnating with alkyd resin and carbonization, electrode can no longer be scratched with a fingernail. It also becomes ringing as ceramics with a slight blow

I have not made electrodes from the new binder yet. However, the remains after carbonization on the electric stove are very strong. Especially a strong last composition. Its adhesion is very strong both to metal and glass. It forms a very dense layer. The remains after heating of last composition on the glass surface I could not separate without damaging the glass. It can only be separated by a metal tool from the metal. Carbonization sugar forms a very soft foam

The density of the coal obtained is comparable with water. However, it depends on the size of the coal powder, binder and the number of impregnations


[Edited on 30-6-2024 by Hexabromobenzene]
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[*] posted on 30-6-2024 at 15:29


Here is the full preparation of the last binder.
Starch was extracted from 2.5 kilograms of flour using water. After the starch at the bottom formed layer, the water was separated and 50 ml of 18% hydrochloric acid was added to the resulting starch suspension. The suspension was heated for 8 hours at 100 degrees to the full hydrolysis of starch.
Then about 300 grams of bone glue were added to the suspension and heating lasted another 5 hours

The quality char from the composition was not exellent. Then another 600 grams of bone glue and 70 grams of old amino acid creatine were added to the mixture. Another 20 ml of hydrochloric acid and hydrozysate prepared from 1.5 kg of starch were added. The mixture was heated at 90 degrees 4 hours. After the synthesis, the binder smells like soy sauce
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[*] posted on 30-6-2024 at 16:29


Also, do not forget that adding only 1-2% iron by weight to fixed carbon leads to the formation of graphite, which is more resistant to combustion, for example. However, it will be difficult for you to remove the iron later
You can add any soluble iron salt to the binder
https://www.researchgate.net/publication/272274928_Study_on_...
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[*] posted on 13-9-2024 at 12:37


The sugar-amine binder should form strong, compact, shiny carbon deposits when calcinated. If there is too much amine or sugar, the deposit will be foamy. You have to find the right ratio. For molasses and bone glue, it is 1 to 3 by weight, respectively. Molasses produces carbon deposits worse than sugar, probably because of the oligomers, but it is cheaper.

Examples of good deposits

[Edited on 13-9-2024 by Hexabromobenzene]

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[*] posted on 30-9-2024 at 15:32


Results of preliminary electrochemical tests of carbon electrodes. Current in a strong salt solution is 10 mA versus 300 mA with 2 metal electrodes and 2 AA batteries as a current source
I recommend treating the results with caution. Electrical contact was made by touching a copper wire. At a voltage of 1.5 (1 battery), the current drops to 1 mA. Perhaps the electrodes need to be galvanically coated with copper. Electrodes made of catalytic graphite (iron salts) may be better


Photo of electrodes made of carbon from HDF floor laminate board. Lithium batteries 18650 for comparison. As you can see, one electrode partially burned during baking due to the lack of protection(iron sheet) in this place. The catalytic graphite electrode is significantly more resistant to combustion

Sugar was used as a binding agent (with sugar-amine binder will be much better) and impregnation of alkyd varnish.

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[*] posted on 26-10-2024 at 02:47
Of course it's interesting !


Quote: Originally posted by Hexabromobenzene  
I made a new binder. This time I used bones extract or gelatin . 1 to 4 to sugar in weight and a little acid. This composition forms a compact layer of carbon with good shrinkage. I think this is the best option.
You can use any water -soluble organic amino acid

Is the this theme interesting to anyone?


Just wanna say that I'm very interested but I don't really have much time to experiment myself,
I made a video on this subject but before you posted about this new binder, so I used sugar and of course, the results were poor.
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[*] posted on 26-10-2024 at 09:46


Does such baking of electrodes not require an Acheson furnace ?
Such a furnace heats baked carbon rods (like TO makes using HDF powder bound with sugar) to 3000 C under a bed of sand using the resistance of the electrode ?
Maybe with a low voltage, high current transformer (a 300A welder, or better a transformer delivering 2-3V and hunderds of A) it can be done by amateurs.
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[*] posted on 27-10-2024 at 10:34


So, after many experiments with the ratio of sugar and amine, I understood how it works
When pure sugar decomposes, you have a soft carbon foam. If you add a little amine, the foam will become stronger. With an optimal ratio, you get compact residue. If there is too much amine, you get foam, but hard.

Sugar with any amine forms a complex polymer - melanoidin. Excess sugar is important. It forms carbon foam, on which solid carbon from melanoidin grows and is also a solvent for the reaction. If your binder consists of pure melanoidin, then due to the large amount of sediment, the mass foams significantly.

Quote: Originally posted by metalresearcher  
Does such baking of electrodes not require an Acheson furnace ?
Such a furnace heats baked carbon rods (like TO makes using HDF powder bound with sugar) to 3000 C under a bed of sand using the resistance of the electrode ?
Maybe with a low voltage, high current transformer (a 300A welder, or better a transformer delivering 2-3V and hunderds of A) it can be done by amateurs.


I use a wood stove for heating. Fiberboard is used to make charcoal because charcoal from HDF is several times denser and requires less binder.
A transformer would be useful for the final baking of the electrode AFTER carbonization. For example, you can make a furnace from a steel pipe wrapped in fiberglass
You don't need temperatures of 3000 degrees. You will never be able to graphitize hard carbon. And catalytic graphitization occurs at 900 degrees. 1100 degrees is enough

[Edited on 27-10-2024 by Hexabromobenzene]
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[*] posted on 27-10-2024 at 11:21


I also recommend adding a larger coal fraction to the baking mixture. This prevents cracks

It probably works as adding stones to concrete
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[*] posted on 28-10-2024 at 04:59


A broken piece of carbon electrode from fiberboard charcoal and sugar as a binder. After baking, the electrode was impregnated with alkyd resin, dried and baked again. It became hard and sounds like ceramics when struck. Before re-baking with alkyd resin, it was scratched with a fingernail

As you can see, even an electrode made of a binder such as sugar can be corrected by impregnation with thermosetting resin. A similar process occurs when baking a sugar-amine binder. Carbon from furan polymers and melanoidins stabilizes the carbon foam from sugar

21.jpg - 600kB 16.jpg - 256kB

[Edited on 28-10-2024 by Hexabromobenzene]
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[*] posted on 27-11-2024 at 07:51


Electrode test in a 10-15% salt solution. Voltage 12V current to 1.5A. The electrode is impregnated with alkyd resin. The place of contact heated significantly, but in any case, such electrodes have conductivity less than graphite and require copper coating. Maybe electrodes made of catalytic graphite (with iron salts) will show better results

I also probably found replacement varnishes for impregnation. Polyethylene and polypropylene soluble in a paraffin overheated higher melting point than plastic. This solution probably will be an excellent varnish for electrodes

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