Should garden biochar have an activated carbon component?
Seems like a good bet that this will turn out to be the case. Activated carbon has a higher active surface area, sometimes an order of magnitude higher, compared to unactivated biochar. This is achieved at high temperature with the introduction of steam and/or chemicals in the absence of oxygen. There is growing interest in this potential characteristic of biochar. Attempts to achieve activated charcoal in a garden-scale kiln involve quenching, putting steam in contact with the charcoal at greater than 500 deg C. While steam activation is workable in an industrial setting [1], further study is needed. Activated carbon has yet to be confirmed as achievable in garden-scale pyrolysis, or even as a characteristic relevant to achieving Terra Preta.
