Activated Carbon

I have been looking into water filtering and finding a lot of misleading information about activated charcoal or activate carbon.  I just wanted to put some information out for the Prepper World.


The first step to making activated carbon is to convert wood into char by pyrolysis.  Pyrolysis is nothing more than decomposition by heat with oxygen.  This produces gases, tars, oils, and char.
Since we are using wood, the char is in the form of charcoal, if we were converting coal it would be called coke.


So how does one burn wood without oxygen?  We set us a retort on a large scale.  We put the fuel in a small steel barrel with air holes along the lower edge.  We then put a tight lid on the barrel and place it inside a larger steel barrel.  Punch a few large air intake holes in the lower edge of the large barrel and several smaller air holes along the top edge. We put food into the big barrel filling up the space between barrels and covering the small barrel.  Light the wood on fire and get it burning.  Punch a hole in the larger barrel lid and put a small smoke stack in it to let the smoke flow out.  Put the lid on the large barrel and let it burn for 24hrs.  The heat will force the wood inside the retort barrel to produce wood gas which will force out all the oxygen and then feed the fire, thus creating
a proper charcoal by pyrolysis.


Now the activation of charcoal is just saying "modification" of char by chemical or physical methods.
The modification removes hydrocarbons and amorphous carbons from the charcoal which gives it the create porosity to make it an effective adsorbent.  We can activate the carbon by reloading our system with fresh wood between the barrels and starting the process over, but we must modify the smaller retort barrel with a pipe and a metal screen at the bottom because we are going to need to pump steam into the retort.  We need to get our retort up to  800-900°C while we have steam pumping through it.
We need to maintain the steam and proper temperature for 20 minutes and we have activated carbon.


Easier said than done, but there it is.