# Sugarcane Bagasse Torrefraction for Fluidized Bed Gasification
## 4 Results and Discussion  
### Thermogravimetric Analysis (TGA)  
Figure 2 shows the thermal degradation of raw sugarcane bagasse under N\({}_{2}\) atmosphere, and it is observed that the thermal degradation profile of sugarcane bagasse showed three stages of mass loss, according to the DTG curve. The first one was below 113 \({}^{\circ}\)C and belonged to the biomass moisture evaporation, accounting for a water loss of 2.3%. Figure 1: Experimental setup for torrefaction studies. Besides, the pyrolysis was concentrated in the temperature range 178-478 \({}^{\circ}\)C and reached the maximum decomposition rate at 356 \({}^{\circ}\)C, which is in line with previously reported results for this agro-fiber [35; 46; 47]. The second decomposition stage contributes to the mass loss of 28.8%, in the temperature range of 178-321 \({}^{\circ}\)C, and the maximum decomposition rate is peaking at 307.4 \({}^{\circ}\)C. Then, a third decomposition stage can be observed at a higher temperature range of 322-478 \({}^{\circ}\)C, with a maximum decomposition rate at 356 \({}^{\circ}\)C, and an associated mass loss of 45.1%. Finally, 22.1% of char is obtained, which belongs to inorganics and the remaining condensed material. Table 1 summarizes the thermal analysis results. The results were obtained from the graphical analysis of the DTG curve shown in Figure 2.  
Lignin, hemicellulose, and cellulose are macromolecular compounds that display different thermal decomposition behavior under pyrolysis conditions [34]. Moreover, their chemical composition can influence biomass pyrolytic behavior due to the interaction of their components [46]. It has been reported that sugarcane bagasse pyrolysis can be represented as an independent parallel reaction model [48]. Each component (hemicellulose, cellulose, and lignin) could decompose at temperature intervals that overlap among each other instead of starting to decompose only after the other one ends. In Figure 2, it is observed that the thermal degradation profile of sugarcane bagasse showed three zones of mass loss. The first one was below 113 \({}^{\circ}\)C and belonged to the \begin{table}
\begin{tabular}{c c c c c c} \hline \multirow{2}{*}{**Sugarcane Bagasse**} & \multicolumn{4}{c}{**Temperature (\({}^{\circ}\)C)**} & \multirow{2}{*}{**Weight Loss (\%)**} & \multirow{2}{*}{**Char (\%)**} \\  & \(\mathbf{T_{ONSET}}\) & & & & \\ \hline First stage & 30 & 58 & 113 & 2.3 & \\ Second stage & 178 & 307 & 321 & 28.8 & 22.1 \\ Third stage & 322 & 356 & 478 & 45.1 & \\ \hline \end{tabular}
\end{table} 
Table 1: Results from thermal degradation of sugarcane bagasse in N2 atmosphere and heating rate of 10 \({}^{\circ}\)C min\({}^{-1}\). Figure 2: Thermogravimetric curve (TG), its derivative (DTG), and second-order derivative (D\({}^{2}\)TG) for sugarcane bagasse biomass under N2 atmosphere and heating rate 10 \({}^{\circ}\)C min\({}^{-1}\). biomass moisture evaporation, accounting for a water loss of 2.3%. The second zone corresponds to the predominant thermal decomposition of hemicellulose, and in the third zone, the degradation of cellulose was the predominant event that took place, while the lignin decomposition starts [34]. For sugarcane biomass, the pyrolysis was concentrated in the temperature range 178-478 \({}^{\circ}\)C and reached the maximum decomposition rate at 356 \({}^{\circ}\)C, which is in line with previously reported results for this agro-fiber [35; 46; 48]. The decomposition of hemicellulose contributes to the mass loss of 28.8%, in the temperature range of 178-321 \({}^{\circ}\)C, and the maximum decomposition rate is peaking at 307.4 \({}^{\circ}\)C.  
Cellulose pyrolysis occurs in a higher temperature range of 322-478 \({}^{\circ}\)C, with a maximum decomposition rate at 356 \({}^{\circ}\)C. The associated mass loss for this temperature range is 45.1%, mainly related to cellulose degradation.