## 3 Results and Discussion
### Thermal Behavior  
#### 3.3.1 Pyrolysis  
The characteristics inferred from the thermal analysis during pyrolysis are useful to determine the capacity of maintaining self-energy balance in corn residues. The pyrolysis profiles of the wastes can be seen in Figure 3, where the weight loss with temperature and over time can be observed. In Table 3, the main pyrolysis parameters for the different samples are shown. Figure 3: (**a**) Thermogravimetric (TG) pyrolysis and (**b**) DTG Pyrolysis. In the representative pyrolysis curves of the four residues, shown in Figure 3, a similar shape was observed for all the cases, with a decrease in weight over temperature, due to moisture loss and the volatilization of compounds in the samples. The thermal degradation, taking place in three stages, can be seen in Figure 3. The first stage is due to moisture removal and the beginning of hemicellulose decomposition [11], up to the beginning of fast pyrolysis \(T_{m}\), which ranges from 269.99 to 284.6 \({}^{\circ}\)C in the different samples. The lower this temperature is, the better the characteristics of the waste for pyrolysis are, obtaining lower temperatures for Ma1, Ma2 and Ma3 wastes whereas the Ma4 sample had the highest \(T_{m}\), which could be due to the contact of this waste with the ground causing higher amounts of impurities. During the second stage, the main pyrolysis process took place, from the beginning of fast pyrolysis \(T_{m}\) to the end temperature of pyrolysis \(T_{f}\), as shown in Table 3. In this second stage, a sharp increase in the weight loss rate took place with further thermal degradation, observing two peaks related to hemicellulose and cellulose decomposition, whereas lignin decomposed during the second and third stage without any characteristic peaks [40]. [PERSON] et al. [12] described the first peak as corresponding to hemicellulose decomposition (usually ranging from 160 to 360 \({}^{\circ}\)C), whereas the second peak corresponded to cellulose decomposition (between 240 to 390 \({}^{\circ}\)C). Temperature peaks where the maximum weight loss took place were lower in Ma1 and Ma2 (287.6 and 287.8 \({}^{\circ}\)C, respectively), and this fact means that they presented greater ease in thermal degradation during the pyrolysis process. The temperature peaks were higher for Ma3 and Ma4, with values of 293.2 and 342.9 \({}^{\circ}\)C, respectively, which implies that Ma4 had worse characteristics for pyrolysis. Compared to other similar wastes, such as rice husk, [PERSON] et al. [15] obtained a value for a temperature peak of 325 \({}^{\circ}\)C, observing better characteristics in corn wastes that were not in contact with the soil, that is, the Ma1, Ma2 and Ma3 samples. In other kinds of biomass, such as woody biomass, higher peak temperatures were observed, as in the case of poplar with peak temperatures at around 345 \({}^{\circ}\)C [31]. Regarding the end temperature for pyrolysis, very similar values were observed; they were slightly lower for Ma3 and Ma4 samples (368.9 and 371.3 \({}^{\circ}\)C, respectively), than for Ma1 and Ma2 (374.5 and 373.6 \({}^{\circ}\)C), respectively. Finally, in the third stage (carbonization), a slow decomposition of the wastes took place, generating ash and fixed carbon as final products. The residual mass of the four samples at the end of the tests (at around 900 \({}^{\circ}\)C), are shown in Table 3. This residual mass included ash content and fixed carbon [8], obtaining lower values for Ma1 and Ma2 (21.30 and 21.34%, respectively) and a higher value for Ma4 (23.96%). These results are in accordance with the ash content and fixed carbon values included in Table 1.