Activated carbon

[suhasnatyan]

Hello, i want join some forum and discussion group on activated carbons, if you know then pl. do post me some.

thanks:-)

[RyanJ]

Hello' date=' i want join some forum and discussion group on activated carbons, if you know then pl. do post me some.

thanks:-)[/quote']

 

If I remember correctly activated carbon (AKA activated charcoal) is just carbon that has been ground up giving it a very high surface area. I'm not shure but I think its measured by how much Nitrogen the carbon can absorb... and I think some chemicals are sometimes used to increase its absorbancy.

 

Cheers,

 

Ryan Jones

[YT2095]

a Discussion group based around activated carbon!

 

well... other that the Obvious likelyhood of NOT finding one, I would imagine the Clientel would be well boring!

it`s subject for thread sure!

a complete userbase though?????

[suhasnatyan]

If I remember correctly activated carbon (AKA activated charcoal) is just carbon that has been ground up giving it a very high surface area. I'm not shure but I think its measured by how much Nitrogen the carbon can absorb... and I think some chemicals are sometimes used to increase its absorbancy.

 

Cheers' date='

 

Ryan Jones[/quote']

 

Thanks Ryan, for giving your views, it will help this topic alive. yes its true that activated carbons has high surface area, but it is not due to grinding on breaking the particle sizes, it is due to their porous structures, which is formed when they are activated*, you are absolutely right in saying that its SA is measured by N2 adsorption, and beside this a rough measure can be made by adsorbing ceratin chemicals(dyes, phenols) too.

Regarding chemicals to increase its adorption propety, it is also done which is known as "chemical avtivation".

I am intersted in keeping this alive, or if anybody comes across of this topic in some other forum then pl. do leave message here.

thanks-

[woelen]

I use activated charcoal for making aniline colorless, before I use that for experiments. Aniline (C6H5NH2) has a strong tendency to become brown on storage, due to formation of all kinds of oxidation products.

 

When the aniline is added to some dilute sulphuric acid and dissolved, then the resulting solution of anilinium sulfate (C6H5NH2)2.H2SO4 is brown/red. With some activated charcoal added to this, it becomes colorless.

 

What effect is responsible for this? Can the brown material also be released again by the activated charcoal?

[YT2095]

IMO, the particulate size would get lodged in the pores of the charcoal, effectively "Locking" them up.

I`m not entirely sure how you`de release them for "capture" after though?

UV light or heating is the typical way to re-active this carbon and flush the pores, but without re-trapping them again in something, I`ve no idea on that one

[BhavinB]

You can treat the activated carbon as an ion-exchange system. So if you knew what the brown stuff was, you can pass some other gas or liquid through the carbon which binds with the brown stuff strongly. This would clear it out.

 

I remember using activated carbon (a while back) to remove Se & Te from sulphate solutions and then clearing it out with water.

[suhasnatyan]

I use activated charcoal for making aniline colorless' date=' before I use that for experiments. Aniline (C6H5NH2) has a strong tendency to become brown on storage, due to formation of all kinds of oxidation products.

 

When the aniline is added to some dilute sulphuric acid and dissolved, then the resulting solution of anilinium sulfate (C6H5NH2)2.H2SO4 is brown/red. With some activated charcoal added to this, it becomes colorless.

 

What effect is responsible for this? Can the brown material also be released again by the activated charcoal?[/quote']

 

your work is really intersting, the first thing which i want to say is that i think aniline is usually adsorbed on active carbons, besides the coloured substances formed. i guess(not sure) it is only the surface phenomena, and if you want you can try chemical regeneration to get your product back.

[woelen]

What I observe is that all colored substance is absorbed by the charcoal. Some of the aniline may also be absorbed, but certainly not a significant part.

 

I may be because the aniline is not present as the free base, but as its acid salt, in the form of anilinium ions, C6H5NH3(+), while the colored impurities probably are present as large neutral molecules.

[YT2095]

I have a British army Avon S10 gas mask with NBC filters, I get my activated charcoal out of these when they`re expired (it`s not a bad source when reactivated).

the thing I`m curious about is how come this charcoal makes lousey black powder?

surely the formula is S + C + KNO3 (in correct ratios) regardless of the charcoal source?

and yet charcoal from other woods (Rose or Willow) makes much better BP.

 

so it it`s down to impurities in the rose wood charcoal, surely the formula is Much more complex than the original 3 ingredients!?

Technicaly pure BP is quite inferior.

[suhasnatyan]

I have a British army Avon S10 gas mask with NBC filters' date=' I get my activated charcoal out of these when they`re expired (it`s not a bad source when reactivated).

the thing I`m curious about is how come this charcoal makes lousey black powder?

surely the formula is S + C + KNO3 (in correct ratios) regardless of the charcoal source?

and yet charcoal from other woods (Rose or Willow) makes much better BP.

 

so it it`s down to impurities in the rose wood charcoal, surely the formula is Much more complex than the original 3 ingredients!?

Technicaly pure BP is quite inferior.[/quote']

Can you pl. tell how that "lousey black powdre" is formed, and ist it S+C+KNO3, also what is BP??,

I am always intersted in knowing anout active charcoals,

thanks in adv

[RyanJ]

Can you pl. tell how that "lousey black powdre" is formed' date=' and ist it S+C+KNO3, also what is BP??,

I am always intersted in knowing anout active charcoals,

thanks in adv[/quote']

 

BP is black powder or gun powder

 

From what I think YT was saying, the impurities in the mix make it better.

 

Cheers,

 

Ryan Jones

[suhasnatyan]

do you know os some site giving some video of activated carbon, showing their porous structures like tunnels and interlinking tunnels

[YT2095]

Can you pl. tell how that "lousey black powdre" is formed' date=' and ist it S+C+KNO3, also what is BP??,

I am always intersted in knowing anout active charcoals,

thanks in adv[/quote']

 

BP = blackpoder (gunpowder) just as Ryanj said.

 

however there is an anomaly when using Activated charcoal, the gun powder doesn`t work as good as it should.

so either our understanding on the chemical reaction(s) that place are flawed/incomplete, Or activated charcoal exhibits strange proterties when used in this simple reaction.

 

if you follow the gunpowder "Recipe" to letter! and use the purest of all the 3 ingredients, you`ll find the result very disapointing, and use Impure charcoal (directly from burnt wood) it works just as it should:confused:

[woelen]

Charcoal from charred wood contains quite a lot of salts (potassium carbonate and possibly others as well), besides carbon. Probably these salts play an important role.

 

I know of a recipe of KNO3, K2CO3 and S, which burns explosively (even when not confined), while a mix with only KNO3 and S does not explode on ignition, when it is not confined. Apparently the K2CO3 plays an important role in this reaction, but I do not fully understand this. K2CO3 is not an oxidizer at all, it contains just spent carbon (CO2, bound to K2O). I think that the K2CO3 in charcoal plays a similar role.

[RyanJ]

I know of a recipe of KNO3' date=' K2CO3 and S, which burns explosively (even when not confined), while a mix with only KNO3 and S does not explode on ignition, when it is not confined. Apparently the K2CO3 plays an important role in this reaction, but I do not fully understand this. K2CO3 is not an oxidizer at all, it contains just spent carbon (CO2, bound to K2O). I think that the K2CO3 in charcoal plays a similar role.[/quote']

 

Heres a guess, could it be that the potassium carbonate easily decomposes giving carbon dioxide. In heat this would expand rapidly.

 

I will try and find some material to research.

 

Cheers,

 

Ryan Jones

[YT2095]

I`m going to have to experiment with this when I get some more time, Impregnating activated charcoal with K carbonates, I`ll be using Reagent grade KNO3 as my "Home made" is always done with excess K OH and Carbonate so as to be sure all the AN has been used.

[suhasnatyan]

yeah i think it will work, but if u do some exp then do tell your exp here too

[suhasnatyan]

do you have any idea, how to make monoliths from powdered activated carbons and its precursors??

[YT2095]

yeah i think it will work, but if u do some exp then do tell your exp here too

 

I/We always do, it`s standard practice to share and compare results amongst ourselves here, although it`ll be some time yet as my Lab is all "upside down" after the move and so all but Crude experiments will have to wait a while, but be certain, it`s on my Experiments-To-Do list;)

 

as for your Monolith question, erm...

[suhasnatyan]

Dear YT, in one of your post you mentioned about regeneration of activated carbon by UV, can you pl. tell us something about that (if possible in detail)

thanks

[suhasnatyan]

I sincerely thanks YT and Ryan for keeping this topic alive and for their knowledge.

Knowledge spreads by sharing so i request viewers to share their views, so that all can get benefit. Dont hesistate to ask and put views..

[YT2095]

regeneration of activated carbon by UV' date=' can you pl. tell us something about that (if possible in detail)

thanks[/quote']

 

I can`t give you any details beyond seeing my father do it with his charcoal from his tropical fishtank filter, it recommended "Charging/Activating" the charcoal with UV light, spreading them out on a tray in bright sunlight was the suggested method, and it always seemed to work

[suhasnatyan]

I "Charging/Activating" the charcoal with UV light

 

I think UV light is good only for organic impurities/materials sticked on active carbons

For inorganics??

[YT2095]

yeah, that sounds likely.

also I started the Potassium doping of the activated charcoal for the BP comparison experiment, after pouring a mixture of potassium hydroxide and carbonate soln, there was a fantasticly satisfying crackly fizzy sound coming out of the carbon as it was absorbing it, much better than rice crispies

it`s currently drying now.