The cheapest, easiet way to start making biochar is what Dr. Hugh McLaughlin calls a "toucan stove"—literally, a stove made out of two cans. With simple tools and minimal skills, anyone can convert a pair of cans into a very efficient, smokeless burner to make biochar for pot tests with germinating seeds and seedlings. This ain't rocket science.

The simplest 2-can stove—the Cowboy Cooker—is two slightly different diameter cans. Stuff the smaller with biomass, then drop open-end down into the larger. Toss them both in a campfire. After fireworks subside, roll the can out, cool, and open for fresh, hot charcoal.

Nathaniel Mulcahy Worldstove in Haiti

Two-can burners are sized nicely to serve as a cooking burner in a household kitchen. This simple, humble service as a kitchen cookstove is a key to a gloal transformation.

Everybody in every household in every community every day must have food, and enough energy to cook that food.

The "3-stone fire" in most of the planet's kitchens burns precious wood to alkali ash by inefficient, smoky combustion that pollutes indoor air—a major cause of public health problems worldwide.

Converting 3-stone fires to 3-can cookstoves—smokeless, making biochar—will alleviate this global health problem, improve family cooking, increase fuel efficiency, curtail forest destruction, produce biochar to improve soil to grow more biomass and better quality food. And that's just a start, without harvesting any energy.

Imagine if one billion household cookstoves every day cook food, feed families, enrich soils, sequester carbon. And biochar is also valuable for water filtration, odor control and waste disposal.

These small, simple can stoves allow people to observe, learn and manipulate the gasification process—how to achieve "smokeburning" smokeless combustion. Any clever person who tinkers with these simple devices learns ways to make them work better. In the process, these inventors discover new insights into controlled combustion technology.

And in the 21st Century, humans must get much more clever about controlled combustion in containers, and how to capture carbon.

TLUD Stove Design

Micro-Gasification what it is, why it works Tom Reed, Paul Anderson, Paul Wever In burning any biomass, gases and vapors called “smoke” are driven from the solid fuel, then burned. For over 100 years, scientists knew biomass combustion is cleaner when air is well mixed with combustible gases, instead of combustion occurring in the solid fuel. Creating combustible gases separate from gas combustion is a distinct characteristic of a true “gasifier.” Practical small scale gasification (micro-gasification) was achieved in 1985 when Dr. Thomas B. Reed created a “Top-Lit Up-Draft” (TLUD) stove. More important, you get to observe and learn the principles of gasification.

These stoves claim a rich diversity of design and construction. Some very efficient burners are built out of used meal cans. Others are industrial machined from specialty metals for long durability under daily heating. Most are adapted from whatever materials are locally available.