Kon-Tiki

In 2014, the Ithaka Institute developed the Kon-Tiki - an open-fire deep-cone kiln that produces high-quality biochar with no external energy, no electronics, and no industrial infrastructure. Since adopted in more than 100 countries, it is the most productive biochar production solution in the world and the technical foundation of the Global Artisan C-Sink Standard.

A cone pit, biomass, and a fire. The Kon-Tiki's design looks simple although the thermodynamics behind it are complex. Understanding why the flame curtain forms, why the cone shape matters, and why the feedstock is loaded from the top is the difference between making biochar and making smoke.

No steel, no welder, no money. The soil pit Kon-Tiki is a conical hole in the ground, lined with rammed clay and rimmed with stones. It works on the same flame-curtain principle as the fabricated kiln - and it can be built in an hour with a shovel.