Charcoal and Activated Charcoal

Doc Ruby

Charcoal is a lot more useful than keeping the barbie going, especially if you're in a mid to long term survival situation. Probably its most important use is a water filter, especially in activated form.

FIrst a quick tutorial on how to make charcoal, this can work on a smaller scale as well.

https://www.youtube.com/watch?v=_aARJXCV_v4

Basically use heat to drive out the moisture and when the wood starts to burn, ie you get blue smoke instead of steam impregnated white smoke, seal the container and let it sit for a day or so. This charcoal can then be ground in a mortar and pestle and stuck in a bottle to act as a filter, this guy has the general idea:

https://www.youtube.com/watch?v=VTllQnZ2HUg

Or you can just scrape it from the top of a normal campfire that used a bit of lumber.

What you really want as a filter though is activated charcoal. This is charcoal that has been treated with acid or oxidised/carbonised, and it works as an almost unbeatable impurities filter, not quite able to turn salt water into potable water but getting just about everything else. In my experience, an amount about half the size of your thumb should be good for modest amounts of water filtration for a month (ie, no lengthy showers in purified water).

Activated charcoal is just normal charcoal that has been processed to make it extremely porous and thus to have a very large surface area available for adsorption or chemical reactions. Just one gram of activated carbon has a surface area in excess of five hundred square meters.

I'm not aware of any field-useful ways to make activated charcoal, although I've heard it can be regenerated under a propane torch, if anyone has any more info on that it would be appreciated.

Charcoal can also be used as a writing implement, to make a strong pitch glue (5 parts melted sap, 1 part powdered charcoal, 1 part finely ground plant material), as camouflage paint, and of course as a fuel source for cooking or heating.

krissovo

I will have to see if I still have research documents on filtration that I once had. Basically the military tested a number systems in order to facilitate a process where we could re-use NBC filters from vehicles and the respirator canisters which are based on activated charcoal.

The basic results were that no matter what the "field" process used there is a major risk of concentrating the toxin with repeated use to dangerous levels.

Doc Ruby

I'd be happy enough if I could figure out how to make fresh activated charcoal to be honest! As far as I can tell, some sort of high pressure steam should do the trick? It would make sense too as that would probably blast the charcoal particles into complex shapes... or something...

eth0

Where do you get activated charcoal here? I want some to have a go off making ultracapacitors with

Being able to make activated charcoal yourself would be better though

Doc Ruby

Most water and any biochem filters have it somewhere in the apparatus, cars have active charcoal filters as well, to filter cabin air, generally found in one of three locations: under the hood, inside the glove box or under the dashboard. Lots of places really. I spotted a few bulk sellers on ebay as well, but I'd be wary of them.

irishlostboy

charcoal is also used as a supplement to aid gastric complaints. mix up a charcoal slurry and spoon into yourself as a low-tech treatment to dellibelly in austere conditions.
remember that charcoal, activated or otherwise will not filter viruses, and some of the nastier bacteria. best bet is to use your improv water filter on rain-water well away from industrial areas.

Grizzly 45

And is a time honoured toothpaste replacement too.Use with a brush as you would normal toothpaste in smaller amounts,and dont scrub vigourously.

slowburner

Grizzly 45 wrote: »

And is a time honoured toothpaste replacement too.Use with a brush as you would normal toothpaste in smaller amounts,and dont scrub vigourously.

I thought that soot rather than charcoal, was used as a toothpaste back in the old days?

Doc Ruby

irishlostboy wrote: »

charcoal is also used as a supplement to aid gastric complaints. mix up a charcoal slurry and spoon into yourself as a low-tech treatment to dellibelly in austere conditions.
remember that charcoal, activated or otherwise will not filter viruses, and some of the nastier bacteria. best bet is to use your improv water filter on rain-water well away from industrial areas.

Boiling or double boiling removes the viruses and bacteria, but won't get rid of most chemicals, poisons, pollutants, and toxins. Activated charcoal gets rid of those. Really for safety you need both in your water filtration system.

Grizzly 45

slowburner wrote: »

I thought that soot rather than charcoal, was used as a toothpaste back in the old days?

Just checked the ol chambers directory of 1891.No,its charcoal alright."Good for encrustions and its chemical action removes fetid odour from the breath.":)

Doc Ruby

After a bit more hunting I managed to find a sorta kinda DIY guide to activating charcoal:

Activating the charcoal is the hard part. To activate charcoal, you need to remove all of the tarry residues and non-carbon impurities that clog up its pores. There are two basic ways to do this: (1) soak the charcoal in an acid solution and then cook at high temperatures for a few hours, and (2) immerse the charcoal in superheated steam (around 1,800 F) for 30 minutes.

V. Forgione describes a process of activating the charcoal using acid from the car battery:

CAREFULLY open the vent caps on the battery. The locals should have a plastic container to collect the acid from the battery. CAREFULLY pour the acid into the container. Now, you should have anywhere from 1.8 liters to over 4 liters of acid, depending on the size of the battery. Let's just say we only need 1 liter of acid, since any more would cost you too much of your drinking water. Battery acid is about 36% sulfuric acid and 64% water.

We should use 2 liters of bottled water to get the acid down to 9%. When mixing acid with water, add the acid to the water, NOT WATER TO ACID. HOT ACID WILL SPATTER! Pour 2 liters of water into another plastic container that the locals have provided, and SLOWLY add acid to the water, stirring all the while. You have 3 liters of acid and that should treat enough charcoal for our use.

Soak the charcoal in the acid, and then reheat in the charcoal pile. With luck, this will activate the charcoal.

So quite damn dangerous and with a random chance of success. I wouldn't advise trying this unless you have to, but activated charcoal is just too useful not to know. Lots and lots of other water filter info there too, well worth a read.

crackcrack30

I take it that seasoned wood is used? is there a particular wood that is most suitable for charcoal than the rest i.e oak or beech?

thanks............

slowburner

Grizzly 45 wrote: »

Just checked the ol chambers directory of 1891.No,its charcoal alright."Good for encrustions and its chemical action removes fetid odour from the breath.":)

Sounds useful .
It's supposed to be a cure for windy dogs too.
What's that book you looked it up in G45 - it sounds v. interesting.

Doc Ruby

crackcrack30 wrote: »

I take it that seasoned wood is used? is there a particular wood that is most suitable for charcoal than the rest i.e oak or beech?

thanks............

What charcoal is, is wood you've cooked the moisture out of basically. Activated charcoal is as close to pure carbon as you're likely to get, its charcoal with all the tar, oil and other impurities flushed out with acid. This forms nano-scale structures which trap poisons and impurities in the water.

Its a lot harder to make charcoal from unseasoned wood, as in it takes longer, and you get more energy per volume from denser woods, so oak charcoal would produce heavier charcoal than say pine charcoal. There's some good information here.

Tigger

Activated charcoal ingested can remove and or neutralise chemical poisons in the gut

Tigger

We were. Among in Wexford last summer and I used to collect drift wood in the morning turn it into charcoal during the day ( in a kettle barbaque) and use it to cook the meat/fish on in the evenings fantastic taste and colours from salt seasoned random wood.

Doc Ruby

Much much better idea than battery acid for activating charcoal I have discovered is using Lye. I suppose you'd chop up the wood base into small pieces first then drop it in lye, before preparing the charcoal normally over a campfire. You need to wash out the lye afterwards though.

This is handy because lye can be easily produced almost anywhere. Usual disclaimers, lye is a hazardous chemical that can cause serious burns, although it is widely used by home soapmakers.

So, activated charcoal for water filters and other purposes out in the wilderness, not too hard to produce.