Top-lit updraft gasifier

A top-lit updraft gasifier (also known as a TLUD) is a micro-kiln used to produce charcoal, especially biochar, and heat for cooking.

[1] A TLUD pyrolyzes organic material, including wood or manure, and uses a reburner to eliminate volatile byproducts of pyrolization.

The process leaves mostly carbon as a residue, which can be incorporated into soil to create terra preta.

Dr Thomas B Reed and the Norwegian architect Paal Wendelbo independently developed the working idea of a TLUD gasifier in the 1990s.

[2] A TLUD gasifier is a considerable improvement on the rocket stove, being a more efficient way to achieve smoke-free combustion of the fuel.