Digestate, as bio-degradable agricultural biogas waste may be subject to the direct management as a fertilizer or, after separation of the solid and liquid phase – solid phase may be subjected to thermo-chemical transformation to biochar. Biochar is a carbonization product with high carbon concentration and relatively low decomposition susceptibility, obtained from various types of organic waste (International Biochar Initiative). Biomas carbonization takes place in the torrefaction process in the temperature from 200ºC to 320ºC. The chemical composition and utility properties of biochar depend on the substrate type and the process parameters. Biochar obtained from biodegradable waste may be an element of carbon biosequestration and used as biofuel, whereas in agriculture – as soil improver, which decomposes for a long time and which positively influences soil fertility, number of biogenic components and physical and water properties. The paper presents characteristic of the torrefaction process, process products and utility values of biochar from the point of view of energy and the agricultural value.