## 5 Discussion
In the literature, torrefaction followed by densification has been reported. Densification is a compaction process that uses equipment such as presses or extruders to increase the durability and improve the physical characteristics of biomass residues [81; 82; 83; 84]. In the case of torrefaction, it is possible to densify the material by friquetting or pelletizing in order to obtain a final product with greater hydrophobic character and high physical and energetic density [85; 86]. With this, the material can have standard sizes that favor transportation, storage, and handling, as well as facilitate the feeding of raw materials in industrial and domestic installations [78]. Apparently, for the lowest temperature used in this test, 200 \({}^{\circ}\)C, there should be no problems during densification, since even the color of the material is still light to dark brown and not black, as seen in samples treated at lower temperatures. Most likely, the state of lignin and cellulose did not change during the test at 200 \({}^{\circ}\)C, but it most certainly did at 300 \({}^{\circ}\)C, making it more difficult without the use of binders. The heating value tends to be higher for torrefied biomass than non-torrefied biomass. However, in contrast to this increase, there is mass loss of the material, as seen in Table 8, and the need to obtain a mass and energy balance to verify the technical-economic application of the thermochemical conversion process to check its feasibility is evident. From the thermogravimetric analysis, it can be inferred that there is an increased concentration of fixed carbon, which is associated with the loss of hydrogenated compounds, in line with the results presented in the work of [PERSON] et al. (2020) [87]. The moisture content decreases from an average value of 3.31% for dry material to an average of 1.03% in material processed at 200 \({}^{\circ}\)C. This follows the normal trend, since it is a process of forced drying of nonstructural water, but it is still present in the material. However, when assessing the moisture content of materials processed at 300 \({}^{\circ}\)C, it appears that it rises again to 3.79%. This rise should be associated with the release of water contained in the material structure and/or the release of hydroxyl radicals, as was portrayed in the work of [PERSON] and [PERSON] (2011) [88]. The results presented in Table 5 indicate that a simple heat treatment at 200 \({}^{\circ}\)C leads to an average energy densification of 1.14, with MY of 82.17% and EY of 93.85%. That is, even without entering the torrefaction zone, still in the over-drying zone, there was already energy densification in the materials under study. Analyzing the results presented in Table 6, for the materials processed at 300 \({}^{\circ}\)C, the energy densification is even more significant, since the EDR reaches an average value of 1.84, with a MY of 30.80% and EY of 56.69%. These values are in line with the values calculated for materials most commonly used in the production of energy from biomass in Europe, such as the maritime pine (_Pinus pinaster_), which has EDR, MY, and EY values of, respectively, 1.55%, 30.50%, and 47.41% [89]. With the results related to the direct increase of heating value, but mainly with the EDR values, there is an energetic densification of the materials. This increase in energy density allows an evaluation of the possibility of exporting materials, especially if they are subjected to a densification process, for example, through the production of pellets [90]. This can contribute to the optimization of logistical processes, which still need to be evaluated and quantified [91]. The combination of the improvement of properties related to logistics, namely the increase in energy density, is in accordance with the properties found in commercial coals, namely bituminous and sub-bituminous coals. In fact, with the energy content above 25 MJ\(\cdot\)kg\({}^{-1}\), the heat-treated sugarcane bagasse approaches the values that these coals normally present.