The Black Phantom is a machine designed to turn biomass into charcoal, a very stable form of carbon that can be stored underground in a carbon sink.

The machine, small enough to fit inside a shipping container and be transported anywhere in the world, is “effectively one giant microwave”. In goes biomass – agricultural waste, wood thinnings, even possibly sewage – and out comes a dense, carbon-rich material. The machine can fix nearly half of the biomass as charcoal.