Biochar (old)

Charcoal, biochar and activated carbon from wood stock are all made using the same process: pyrolysis. This is the carbonisation of wood by heating it in an oxygen depleted environment. In simple terms, charcoal for burning is made with very little oxygen present. This prevents any of the tars and oils that inhabit the pores within the structure of the wood from burning away. The charcoal is dense and has a high calorific value. If you introduce some oxygen into the process the volatiles start to burn away, creating a sponge like structure within the wood. The charcoal becomes lighter and more friable. This process is known as ‘activation’. Introducing oxygen is certainly not the best way to activate charcoal, but it is the easiest (you can’t make high quality activated carbon this way).

So at one end of the scale you have charcoal, in the middle you have biochar (which is partially activated) and at the other end is activated carbon. The ecological value of the charcoal we produce very much depends on how activated it is; the more activated the better! 

So once you have produced charcoal, how do you know that it’s biochar? There are a number of tests that you can do, from seeing how well it absorbs, to seeing how dense it is. As you will see from the following studies, our charcoal performs extremely well compared to commercial biochar samples, which is why we can use it so effectively for filtering water.

Once you have produced biochar and tested how effective it is, there are many things you can do with it. You can use it in your garden to help trap nutrients in your soil or to filter collected water for general use (please do not use it to filter water for drinking). There are many possibilities!