## 4 Discussion  
### Biochar Yields  
According to the results, the lowest biochar production output was observed for the eucalyptus biomass. This could be attributed to the presence of abundant fine and small fractions such as leaves and branches, leading to a significant amount of material that volatilizes faster than wood itself [43]. Figure 6 shows a comparation of values for the three different biomasses. The obtained values are consistent with previous experiences conducted with biomass, particularly slow pyrolysis [44]. Nevertheless, achieving performance rates of less than 50%, which is typical in the case of solid wood, is primarily due to the inherent nature and variability of the biomass used, characterized by residual heterogeneous materials varying in size, constituents, and granulometry [45]. Previously, studies have reported yields ranging from 26% to 58% for pine within a temperature range of 300 to 450 \({}^{\circ}\)C [42].  
Previously, studies [46; 47] have found that the yield biochar varies significantly depending on the pyrolysis technique used. Slow pyrolysis conducted in an oxygen-free environment yields approximately 30% more charcoal compared to fast pyrolysis (12%) or gasification (10%). The results obtained are consistent with those of slow pyrolysis. Extended reaction times promote polymerization, thereby increasing production [13], while moderate temperatures and a short residence time typically result in more liquids [48].  
\begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Original Biomass**} & \multicolumn{3}{c}{**Final Biochar**} \\ \cline{2-7}  & **N (\%)** & **C (\%)** & **H (\%)** & **S (\%)** & **N (\%)** & **C (\%)** & **H (\%)** & **S (\%)** \\ \hline _P. pinaster_ & 0.89 & 48.21 & 6.71 & \textless{}0.30 & 0.84 & 77.62 & 2.59 & \textless{}0.30 \\ _A. dealbua_ & 0.82 & 49.51 & 6.90 & \textless{}0.30 & 1.63 & 81.06 & 2.66 & \textless{}0.30 \\ _[PERSON]_ & 0.92 & 49.91 & 6.88 & \textless{}0.30 & 1.19 & 76.17 & 2.85 & \textless{}0.30 \\ \hline \hline \end{tabular}
\end{table}
Table 7: Elementary analysis of N = Nitrogen, C = Carbon, H = Hydrogen, and S = Sulfide.  
\begin{table}
\begin{tabular}{l c c c c c c} \hline \hline \multirow{2}{*}{**Cationic Analysis (mg/kg)**} & \multicolumn{2}{c}{_P. pinaster_} & \multicolumn{2}{c}{_A. dealbua_} & \multicolumn{2}{c}{_E. globulus_} \\ \cline{2-7}  & **Biomass** & **Biochar** & **Biomass** & **Biochar** & **Biomass** & **Biochar** \\ \hline Ca & 2280 & 14,560 & 1760 & 13,880 & 4960 & 16,600 \\ Na & 360 & 526 & 376 & 580 & 1960 & 3700 \\ K & 2800 & 8870 & 1720 & 5480 & 3880 & 14,200 \\ Mn & 148 & 459 & 120 & 378 & 200 & 880 \\ Cu & 8 & 265 & 2.4 & 36 & 4 & 40 \\ P & 1216 & 2590 & 960 & 2120 & 1320 & 3320 \\ Mg & 680 & 3620 & 520 & 2640 & 2080 & 5520 \\ Fe & 680 & 2290 & 64 & 680 & 124 & 580 \\ Zn & 16 & 90.5 & 8 & 38 & 8 & 52 \\ Cr & 12 & 14 & \textless{}1 & 6 & \textless{}1 & 4.4 \\ Ti & 36 & 420 & 2 & 516 & 8 & 70 \\ Co & 0.1 & 3.3 & \textless{}0.1 & 1.05 & \textless{}0.1 & 1.2 \\ Ni & 5.6 & 12.2 & \textless{}0.5 & 4 & 2 & 4.8 \\ Si & 1320 & 2860 & \textless{}50 & 972 & 320 & 1360 \\ Al & 1280 & 4280 & 84 & 512 & 360 & 1020 \\ S & 480 & 980 & 400 & 382 & 660 & 580 \\ Cl & 233 & 402 & 1589 & 1480 & 585 & 541 \\ \hline \hline \end{tabular}
\end{table}
Table 8: Cationic analysis.