Apparatus and associated methods relate to cooling hot biochar based on applying cool gas directly to the hot biochar. The gas may be steam comprising water vapor. Biochar may be cooled in a cooling chamber by cool steam injected into a steam loop configured to cool the steam. The biochar cooled with steam may be dried in a drying chamber by dry gas injected from a gas loop. The gas may be hydrocarbon gas. Biochar may be heated in a processing chamber. Heated biochar may be cooled in a cooling chamber by cool hydrocarbon gas injected to the cooling chamber. Biochar in the processing chamber may be heated with heat recovered from cooling. Filtered byproducts and tail gas may be recovered from the cooling chamber. Tail gas may be recycled. Various direct biochar cooling implementations may produce biochar having enhanced carbon content, increased surface area, and a hydrogen stream byproduct.