The fuel and energy crisis and the increasing pollution of the environment are one of the pressing problems facing humanity today. In this regard, the question of finding new alternative energy sources is urgent. Today there is an increasing interest in solid biofuels and new methods for improving the properties of biofuels are being developed and improved, such as grinding, drying, pressing, and more recently, heat treatment. Thermal methods of impact on biomass require special attention of researchers, because while their consumption consumes some energy, it leads to an increase in the cost of production. But at the same time, they allow not only to increase the specific energy characteristics of biofuels by removing moisture and ballast components, but also to obtain fuel with new useful features (such as hydrophobicity, low greenhouse gas emissions, diminishing smoke and odours, no corrosive substances). Depending on the biomass heat treatment modes, a different end product can be obtained, and changes in it can be estimated by the weight loss. Investigations of this process were carried out in the educational scientific laboratory "DAK GPS" of the State Agrarian and Engineering University in Podilya at the plant for the torrefaction of tape-type biomass with passive interaction with the material. Control automatics allow to adjust and maintain the temperature in the thermal chamber, as well as the speed of movement of the tape, which determines the residence time of the biomass under the influence of thermal action. During each 10-minute heat treatment cycle in 20 ℃ increments, mass loss was determined, and additional factors were recorded that could indicate the beginning of internal changes in the material being studied (smoke, odour, etc.). As a result, the conducted research proved that the torrefaction process of different raw materials meets its own temperature range, in which there are active changes of material, namely converts raw biomass into torrefied product. This range for the studied samples is 40-50 ºC, in particular for barley and soybeans the process of torrefaction begins at 185-195 ºC and ends at 230-240 ºC, for poplar, willow and miscanthus these figures are respectively 235-245 ºC and 280-300 ºC. As shown by the studies, for most biomaterials of plant origin we can distinguish the beginning of intensive transformation and its end, after which there is a sharp slowdown in the weight loss, and accordingly, in the energy density of the samples.