The invention provides for methods, devices, and systems for pyrolyzing biomass. A pyrolysis unit can be used for the pyrolysis of biomass to form gas, liquid, and solid products. The biomass materials can be selected such that an enhanced biochar is formed after pyrolysis. The biomass can be pyrolyzed under specified conditions such that a selected biochar core is formed. The pyrolysis process can form a stable biochar core that is inert and/or resistant to degradation. The biochar or biochar core can be functionalized to form a functionalized biochar or functionalized biochar core. Functionalization can include post-pyrolysis treatments such as supplementation with microbes or physical transformations including annealing and/or activation.