Making Activated Carbon

[Music] all right everyone welcome back Kody's labs so today I want to attempt to make activated carbon so this is stuff that you can buy from the store it's about six dollars per nine ounce little container here but I want to try making some of my own so I have here a box of hardwood charcoal this is just store-bought I did try making some but I ended up burning it all up in a failed attempt so yeah so essentially what this is is carbon a little bit of ash and it's guts a structure which gives a pretty high surface area fact if you look at it real close you see all kinds of little tiny holes and pores which was originally the vascular structure of the plant and if you got chemicals it like to stick to carbon well that makes a pretty good surface for to do so but it could be a lot better like this charcoal here it still has quite a lot of area where there's just no pores and also this still contains quite a lot of residual oils and tar which plug many of the holes it also makes it so it's hydrophobic and water doesn't like to actually go through this very well in order to create activated carbon what we need to do is increase the effective surface area of the charcoal now there's many ways to do this one of them is just get a hotter if you make the charcoal at a higher temperature more of those tars will vaporize often there'll be more pores open what I'm gonna do is react it with superheated steam so let me explain what that's going to do so imagine that this piece of clay here is a piece of charcoal and the tape is some bits of tar as you can see right here that piece of tar is covering up one of the pores now we can get this hot and drive off the tar that's pretty simple or we could like use sodium hydroxide or something to dissolve it off and now we're left with a piece of carbon with a bunch of little holes in it now if we react this with oxygen at high temperatures you'll burn the charcoal oxygen is kind of like a knife it burns away the carbon pretty indiscriminately whatever it touches it burns off and removes making the piece of carbon smaller so what I'm going to do is react the carbon with water instead of air now you might be thinking well water doesn't react with charcoal well no it doesn't unless you get it very hot you know it takes a lot of activation energy but water even at very high temperatures is more gentle it's more like taking a stick to it and it'll pull off little bits some parts of the charcoal are more easy to react with than others there might be catalysts present which help the reaction along but only in certain places there might be a piece of ash that the water can't react through water can also last long enough that instead of reacting with the first little bit of carbon it runs into it can actually bounce around and make it down into the pores before reacting so even the inside of the pores can become more porous in fact it's reasonable to assume that I could increase the surface area by a couple of orders of magnitude let's say you accidentally ingest a poison well you'd much rather eat 10 grams of activated carbon than a kilogram of charcoal like this isn't even going to fit in your stomach so activated carbon is very useful to have but I will point out that in a lot of cases like water purification and stuff you know if you just have a barrel of charcoal that'll work it'll still clean your water there's nothing really special about the activated carbon other why other than you need a smaller mass of it to absorb the same amount anyway let's get to activating it the first step of course is gonna be to grind this up into a smaller size [Music] [Music] so now that I've got the charcoal crushed the pieces are all different sorts of sizes and so I need to classify them down now the pieces that are too big here I can either crush again or what I'm actually going to do is just throw them over my shoulder into the compost heap yeah that'll turn it into biochar so the idea here is get the pieces down as small as I can so that the water vapor the steam can penetrate the entire particle if the particle is too big only the very outside of it might become activated so even this stuff here is probably too big for my DIY version but I am gonna save that and what I'm gonna end up with is a bunch of very fine material here which is mixed with dust now the dust is actually a problem of its own because if there's too much of it the particles are all different sizes then the steam and hot gases might not be able to penetrate it at all and most of it won't get activated so it's as if this whole thing is one big piece of charcoal and so what I'm gonna do is scoop it up like this using this finer screen no finer than this one and sift out all the dust and I might use the dust or something else and now since the particles are all about the same size their packing efficiency has decreased gas can easily pass through them so I'll just finish this up so here is my crushed in screened charcoal all of the pieces should be roughly the same size so what I'm thinking is I'll have my electric furnace here and I'll put the charcoal inside of a stainless steel flask it's got to be stainless steel because the superheated steam will burn iron if it's on alloyed and have like a little dish at the bottom maybe fill this with charcoal here to keep the air out and then have a stainless steel tube come in go up to the top and then maybe have like a tea kettle or something over here to produce the steam and of course this will be filled my crushed charcoal building okay so this is what I've come up with you see the kettle here and if I pull the furnace apart you see how I did that I had some spare fire brick I just cut to fit everything and here is the reaction vessel itself there's another stainless steel dish that goes here now if you can see down in there the tube just bends up and goes into the top of this tube end this tubing as sharp as I did I ended up filling it with tin and that keeps it from collapsing it wasn't easy to bend but I was able to do it let's just load it up now I don't want to fill this all the way up just do maybe three-quarters of the way full I should do it that's for the charcoal to remove the oxygen let me use these large pieces so I don't get them confused and as for the charcoal that I'm just heating up without the steam I'm just gonna fill up a little soup can here put it inside of another soup can add some charcoal around that keep the oxygen and steam out and we'll just set that and are right there so it gets heated the same I'll just assemble it all this back up heat it to at least 1700 degrees Fahrenheit I get the heat there's the water well they don't need that much it's gotten a bit dark or finally up to temperature so I'm gonna heat the kettle just blowtorch here and once it's boiling close the lid and send some seem into the chamber candles boiling I'm gonna put in the steam look at that it's carbon monoxide and hydrogen burning from the steam reacting with the charcoal and producing water gas nice that means it's working if I remove the steam source stops immediately okay so I'm going to do this for a few minutes and then I'll stop and let it heat back up again now this process takes energy so the charcoal in there is going to be cooling off as I do this so I can't put the steam in continuously fact I can kind of see it even slowing down a bit be a good indicator [Applause] right so this is the fourth time I've injected steam they have totaled about 10 minutes worth of steam injection and this is probably going to be my last time in fact I've unplugged to the furnace for my light now obviously it would be better if I could stir the charcoal as I'm injecting the steam but look the way I've got it set up the rate that I'm injecting the steam is so high and the rate of heating is so slow the charcoal at the top will react with the steam before the charcoal at the bottom but as the charcoal reacts to the steam it cools off because the reaction is endothermic and the charcoal below that will still be hot and so the steam will pass through into the still hot charcoal and it should in theory react with the entirety of the mixture now normally I would have taken it off by now because it's probably done but I'm gonna continue injecting this time because I'm gonna let it cool off now and it may as I'll cool it off with the steam it's finally cooled off so let's open it up and see what we got yeah that charcoal there so this should just pretty much have just gotten hot I don't think any steam would have gotten into there just dumped a bunch out here we're gently the sizes different so I'll be able to sort it that should be our activated charcoal hopefully let's go test it so here's our control the charcoal that has had no treatments done to it this is the charcoal we've activated and inside this can should be the charcoal which just got hot let me dump out the material that we filled in around the sides because that might have gotten interacted with steam and air now there's the charcoal along with some little bits from the can I might run that through a screen just to pull those out wow those bits of stuff err I'm looking see that flying around now from just playing with this a little bit I've noticed that the stuff that I ran the steam through feel slightly denser than the other charcoals so let's pull out my scale and let's actually have a look at that little beaker here let's just fill it up to control to the top so just shakes off 19.3 of your hands dump it back out let's put up with the activated charcoal do the same thing okay twenty-three and a half it is heavier denser now I would have thought that it would become less dense but it kind of makes sense see - didn't go anywhere you know there's less carbon but the same amount of ash and ash is quite heavy let's check the stuff that we just got hot let's see if the steam had any thing to really do with it interesting my guess is the heat must cause the the pieces to contract a little bit that is cool I didn't know that okay so let's continue with our tests I need to go get some iodine so I have here an iodine solution of thirty one and a half million Oller so that's about four milligrams of iodine per milliliter and charcoal will absorb the elemental iodine and the amount that absorbs should be proportional to the surface area so what I'm gonna do is take a test tube which I have labeled kind of hard to see and I am going to put the test tube on a scale to measure the way the test tube tare that away I'm going to attempt to put in about a gram of the charcoal so this is the control which hasn't had anything done to it okay so now that I've got a gram of the charcoal and the test tube I'm going to add some hydrochloric acid approximately two milliliters worth is to make sure that the charcoal is acidified because the alkaline ash and the charcoal will react with the iodine let me get this acidified I might even warm it up with the torch a little bit just to make sure it reacts now that I have the charcoal acidified I'm going to add 25 milliliters of the iodine solution this is iodine and alcohol by the way hopefully this fits ah perfect I'm gonna have to find a cap for this so here's all my samples I'll just kind of give these a shake every now and then okay so it's the next day these have sit for about twelve hours and you can already see that the activated carbon test tubes are significantly lighter than the non activated carbon test tubes this would indicate that they have absorbed significantly more iodine and in fact my activated carbon appears even lighter than the commercially activated carbon which would indicate mine's better but to get some actual numbers I have set up a burette and a sodium thiosulfate solution and before you ask it did occur to me that since I added two milliliters of hydrochloric acid each vial it diluted the solution slightly so I will need less of the thiosulfate to neutralize the iodine so what I'm going to do is transfer 10 milliliters of the iodine solution into this little beaker and then I'm gonna fill the BRIT with the thiosulfate and we're going to titrate and see just how much iodine was absorbed from the solution so let's start with my activated carbon okay now I'm going to run a cotton ball down its throat in order to filter out any charcoal that's floating around in the solution that could mess with my results I have to pull some out first use a pipette transfer it okay there's my 10 milliliters yeah transfer this over to here rinse it with a bit of water concentration here doesn't matter it's the amount of iodine in 10 milliliters so I need to make sure I have the 10 milliliters of the iodine solution hey the dred is full let's put that under it beginning the titration a little bit time give a stir oh there's a bubble crisis averted there's pretty much just drop wise until a solution goes clear there it is that took five six seven point seven milliliters of the thiosulfate solution so I just wrote down that result here and I guess it's time to work on the other three [Music] so here are my results the control the original charcoal was able to absorb only 2 milligrams of iodine per gram the stuff that we heated up managed to absorb 30 milligrams per gram which is quite a lot actually that's a pretty substantial jump there the stuff that I activated the steam managed to absorb ninety two and a half milligrams per gram is more than the stuff that we just heated up so the steam definitely helped and the commercial activated carbon absorbed 89 milligrams per gram now keep in mind there's probably pretty big error bars on these numbers but it still shows that I definitely was able to activate it and to a level comparable to what is commercially available so there you have it you now know how to make activated carbon so if you're wondering what my yield was this is about two ounces I lost a bunch of it I'm sure I could do better but considering only used about two kilowatt hours worth of electricity it's still cost-effective as long as I can do multiple batches I attempted to make some using a more primitive method you know not using an electric kiln that failed but I'll still upload the video probably to the second channel if you guys want to go check that out feel free and also speaking of charcoal I finally got back together with good and basic and we burned a whole lot of it to smelt the utah bog iron so if you guys want to check that out i'll leave a link for that as well so hope you enjoyed see you next time [Music] [Music]

Channel: Cody'sLab

Views: 750,128

Rating: 4.9587364 out of 5

Keywords: carbon, iodine, activate, biochar, charcoal, diy, homemade, make, chemistry

Id: GNKeps6pIao

Length: 20min 4sec (1204 seconds)

Published: Wed Mar 27 2019

Reddit Comments

[u/YOUREABOT]

Hey, Cody got some more chemistry equipment (?)! Loved the titration.

[u/afromagicdanny]

It’s not the video I found before my camping trip idk what happened to the video I watched about creating filters but I hope it’s helpful, this video goes over the same topics of the one I watched and a similar process to making clean charcoal, if this posts seems out of place go to my first post it explains everything I’m talking about in detail, enjoy.