## 3 Results
### Thermogravimetric Analysis
The higher devolatilization temperature observed for the blended samples torrefied at 300 \({}^{\circ}\)C and 350 \({}^{\circ}\)C was because the samples had undergone some level of devolatilization during the torrefaction process. This devolatilization phase is mostly associated with the hemicellulose component that decomposes between 190 and 320 \({}^{\circ}\)C. Due to hemicellulose low-temperature degradation, it usually results in less char and tar compared to the other polymer components [26]. Char oxidation representing the third stage, started at varying temperatures for all samples, indicated a variation in their thermal stability as well as their complex chemical composition. For instance, M\({}_{\text{a250}}\), M\({}_{\text{e250}}\) and M\({}_{\text{e350}}\) samples converted to char at 620 \({}^{\circ}\)C, 700 \({}^{\circ}\)C and 810 \({}^{\circ}\)C, respectively. Hence, in the event of gasification, this would serve as the set temperature to avoid the occurrence of slagging and agglomeration at higher temperatures. The concentrated mineral matter in the form of a solid residue (ash content) that emerges after the thermal treatment of the samples at 900 \({}^{\circ}\)C was highest in M\({}_{\text{a350}}\) and M\({}_{\text{e300}}\) samples with values of approximately 37% compared to other samples because of the directly proportional relationship existing between torrefaction temperature and yield of solid residue. The thermogravimetric analysis aided in the determination of important parameters such as ash and volatile matter that may influence the thermal degradation of the samples. Table 1 presents the composition of the blended samples of torrefied SS and BG in terms of moisture content (MC), fuel ratio (FR), volatile matter (VM), ash content (AC) and fixed carbon (FC). The condensable and non-condensable vapor released during the thermal degradation of the samples is represented by the volatile matter. As observed from Table 1, the VM of the 50% SS to 50% BG blend (M\({}_{\text{a}}\)) decreased by 3.96% and 13.79% at the higher temperatures of 300 \({}^{\circ}\)C and 350 \({}^{\circ}\)C. Similarly, for 75% SS and 25% BG blend, VM decreased by 12.71% and 19.72% at 300 \({}^{\circ}\)C and 350 \({}^{\circ}\)C, respectively. In contrast, an increase in the volatile matter was observed for M\({}_{\text{a}250}\) and M\({}_{\text{e}250}\) samples, which can be attributed to more decomposition of hemicellulose as 250 \({}^{\circ}\)C serves as the peak temperature for hemicellulose degradation. The decrease in VM exhibited in the other samples is desirable because it enhances the heating value of biomass originating from the reduced oxygen content of biomass impacted by an increase in torrefraction temperature [32]. In addition, low VM will reduce the formation of tars, which is a major problem to counter during biomass gasification. Tar condensation at reduced temperature causes fouling and blocking of process equipment such as internal combustion engines. Thus its minimization in fuel gas is desirable [33,34]. In light of this, VM is an important parameter of consideration in the design and layout of a gasifier system, gas cooling unit and cleaning unit for tar elimination. Moisture content, as observed, showed a decreasing trend with the increase in torrefraction temperature with the exception of M\({}_{\text{a}350}\). The increase in the moisture content of M\({}_{\text{a}350}\) may be because of the hydrophilic nature of sugarcane bagasse due to its high hemicellulose composition. Hence, at a severe torrefraction condition of 350 \({}^{\circ}\)C, it tends to absorb moisture more as the hemicellulose component degrades [23]. On the same note, [PERSON] et al. [6] study showed a decrease in the moisture content of energy sorghum from 7.83% to 2.05% and sweet sorghum bagasse from 9.29% to 5.51% after torrefraction at 250 \({}^{\circ}\)C. Another study equally showed a decrease in moisture content from 4.80% to 0.87% as torrefraction temperature increased from 200 \({}^{\circ}\)C to 300 \({}^{\circ}\)C [31].