# Characterization of Congolese Woody Biomass and Its Potential as a Bioenergy Source
## 3 Results
### Biochemical Compositional  
Biochemical analysis using the Van Soest method provides information on cellulose and lignin content. Table 6 summarizes the biochemical analysis results of WB. The cellulose content in WB ranges from 17.47% to 32.55%, which is higher than the hemicellulose content, ranging from 11.01% to 23.39%. These values align with those reported by [22]. However, WB has a relatively low lignin content. The biochemical composition results obtained in this study are similar to those reported in the literature [27; 2]. The decomposition steps of biomass during thermochemical conversion depend on its biochemical composition. For example, pyrolysis decomposes hemicellulose, cellulose, and lignin at temperatures ranging from 220-315 \({}^{\circ}\)C, 315-400 \({}^{\circ}\)C, and 500-900 \({}^{\circ}\)C, respectively [2]. Pyrolysis of cellulose and hemicellulose produces a higher bio-oil yield than lignin, which significantly contributes to the formation of residual char. Generally, higher nitrogen content makes the feedstock less suitable for solid fuel and bio-oil production. Proximate analysis results showed that the moisture content in WB1, WB2, WB3, WB4, and WB5 ranged from 4.7% to 13.4%, consistent with the literature [8; 9]. Higher moisture content in biomass requires more heat during thermochemical processes to remove the moisture. The levels of fixed carbon (FC) and volatile matter (VM) are crucial for determining the ignition and subsequent gasification/oxidation characteristics of biomass, depending on its use as an energy source [2]. The volatile matter content of the WB samples ranged from 74.6% to 77.3%. Higher ash content in biomass proportionally reduces the energy content of the fuel. During thermochemical conversion, the chemical composition of the ash can lead to operational problems, particularly in combustion processes where ash can form slag at \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Analysis** & **WB1** & **WB2** & **WB3** & **WB4** & **WB5** & **WB6** \\ \hline Hemicellulose (\%) & 11.01 & 14.8 & 20.7 & 13.1 & 23.4 & 12.44 \\ \hline Cellulose (\%) & 17.0 & 18.7 & 17.5 & 27.1 & 32.6 & 31.5 \\ \hline Lignin (\%) & 7.5 & 12.9 & 12.0 & 7.3 & 18.5 & 18.48 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Biochemical analysis of woody biomass. \begin{table}
\begin{tabular}{l c c c} \hline \hline
**Parameters** & **Mean** & **Maximum** & **Minimum** \\ \hline \multicolumn{4}{c}{**Wood Biomass**} \\ \hline Volatile Matter (\%db) & 76.29667 \(\pm\) 1.07595 & 77.3 & 74.58 \\ \hline Moisture (\%db) & 7.87167 \(\pm\) 3.07025 & 77.3 & 74.58 \\ \hline Fixed Carbon (\%db) & 12.655 \(\pm\) 1.09478 & 14.63 & 11.4 \\ \hline C (\%db) & 44.425 \(\pm\) 1.00685 & 45.85 & 43.4 \\ \hline H (\%db) & 5.785 \(\pm\) 0.22125 & 6.1 & 5.5 \\ \hline N (\%db) & 0.84333 \(\pm\) 0.29944 & 1.3 & 0.5 \\ \hline O (\%db) & 48.83833 \(\pm\) 0.78027 & 50.2 & 48.03 \\ \hline HHV (MJ/kg) db (Dulong) & 14.58333 \(\pm\) 0.34881 & 14.9 & 13.9 \\ \hline HHV (MJ/kg) db (Friedl) & 17.76 \(\pm\) 0.33615 & 18.2 & 17.4 \\ \hline HHV (Proximate analysis) & 16.825 \(\pm\) 1.42776 & 19.23 & 15.26 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: A statistical analysis of the proximate analysis, ultimate analysis, and the HHV for wood biomass. higher temperatures. The results of this study showed that the ash content in the wood biomass was low and comparable with [28; 29]. Table 7 provides a clear statistical analysis of the biochemical analysis of the WB. Hemicellulose showed a mean value of 15.91% \(\pm\) 4.98%; we observed that the values (11% to 23%) are typical for woody biomasses, where hemicellulose generally represents 15% to 35% of the wood depending on the species. The low proportion relative to cellulose reflects the secondary structural nature of hemicellulose in cell walls. Our results corroborate results reported by [26]. Mean values of cellulose are represented (24.07% \(\pm\) 7.20%).